Use of a parp inhibitor in combination with chemotherapy in the treatment of cxorf67 high expressing tumors

Abstract

This invention provides the use of a PARP inhibitor in combination with chemotherapy in the treatment of CXorf67-overexpressing tumors. Specifically, it provides the use of a combination of active ingredients for the preparation of a drug or formulation for the treatment or synergistic treatment of CXorf67-expressing or overexpressing tumors, wherein the combination of active ingredients comprises: (Z1) a PARP inhibitor; and (Z2) a chemotherapeutic agent. It was unexpectedly discovered for the first time that tumor cell lines or tumor tissues expressing or overexpressing CXorf67 are more sensitive to PARP inhibitors in combination with chemotherapy (e.g., PARP inhibitors in combination with platinum-based drugs), the CXorf67 gene or its protein can be used as a biomarker for detecting the sensitivity of tumor cells to PARP inhibitors in combination with chemotherapy, and that PARP inhibitors and chemotherapy have a synergistic therapeutic effect.

Description

Technical Field

[0001] This invention belongs to the field of biomedicine. Specifically, this invention relates to the application of PARP inhibitors combined with chemotherapy in the treatment of CXorf67-overexpressing tumors. Background Technology

[0002] Homologous recombination (HR) repair pathway is a fault-free repair process that primarily utilizes homologous DNA within the cell as a template to repair broken DNA during the S / G2 phase of the cell cycle. Defects or deficiencies in HR can lead to genomic instability, subsequently contributing to tumor development and progression. For example, mutations in genes such as BRCA1, PLAB2, and BRCA2 within the HR pathway have been found in many tumors. These mutations can prevent the effective repair of DNA double-strand breaks, causing alterations, rearrangements, and mutations in cellular gene copy numbers, ultimately leading to tumors and diseases such as ovarian cancer, breast cancer, pancreatic cancer, and prostate cancer.

[0003] In 2005, two laboratories simultaneously reported that PARP inhibitors could selectively kill BRCA1 / 2-mutated tumor cells. Subsequent studies found that tumor cells with BRCAness (containing HR deficiency but not BRCA1 / 2 mutations) were also sensitive to PARP inhibitors. However, further research revealed that while various PARP inhibitors exhibited comparable inhibitory efficiency in inhibiting PARP catalytic activity, their cell-killing effects varied significantly. How to further efficiently kill tumors with HR repair pathway defects remains unknown.

[0004] Therefore, there is an urgent need in this field to develop a more sensitive and effective treatment for tumors with defects in the HR repair pathway. Summary of the Invention

[0005] The purpose of this invention is to provide a more effective treatment for tumors that express or highly express CXorf67, especially a treatment method that combines PARP inhibitors with chemotherapy to achieve a synergistic therapeutic effect.

[0006] Another object of the present invention is to provide the use of the CXorf67 gene, mRNA, cDNA or protein or a detection reagent thereof as a biomarker for detecting the sensitivity of tumor cells to PARP inhibitors in combination with chemotherapy.

[0007] Another object of the present invention is to provide the use of the CXorf67 gene, mRNA, cDNA or protein or a detection reagent thereof for the preparation of diagnostic reagents or kits for detecting the sensitivity of tumor cells to PARP inhibitors in combination with chemotherapy.

[0008] In a first aspect of the invention, there is provided the use of an active ingredient combination for preparing a medicament or formulation for treating CXorf67-expressing or highly expressing tumors, or for synergistically treating CXorf67-expressing or highly expressing tumors, wherein the active ingredient combination comprises:

[0009] (Z1) First active ingredient: PARP inhibitor; and

[0010] (Z2) Second active ingredient: chemotherapy drugs.

[0011] In another preferred embodiment, the PARP inhibitor is selected from the group consisting of: Talazoparib, Olaparib, Veliparib, Rucaparib, Niraparib, Fluzoparib, Pamiparib, or combinations thereof; preferably, the PARP inhibitor is selected from: Niraparib.

[0012] In another preferred embodiment, the dose of the PARP inhibitor is 10-100 mg / kg, more preferably 20-80 mg / kg, even more preferably 30-70 mg / kg, and most preferably 50 mg / kg.

[0013] In another preferred embodiment, the chemotherapeutic agent includes drugs that disrupt DNA structure and / or function (such as platinum-based drugs).

[0014] In another preferred embodiment, the chemotherapy drug is a platinum-based drug.

[0015] In another preferred embodiment, the platinum-based drug is selected from the group consisting of Cisplatin, Carboplatin, Nedaplatin, Oxaliplatin, lobaplatin, or combinations thereof; preferably, the platinum-based drug is selected from Carboplatin and / or Cisplatin.

[0016] In another preferred embodiment, the dosage of the platinum-based drug is 0.1-20 mg / kg, more preferably 0.5-10 mg / kg, even more preferably 1-5 mg / kg, and most preferably 2 mg / kg.

[0017] In another preferred embodiment, the drug or formulation further includes a pharmaceutically acceptable carrier, diluent, or excipient.

[0018] In another preferred embodiment, the drug or formulation may also include other tumor therapeutic agents.

[0019] In another preferred embodiment, the CXorf67-expressing or highly expressing tumor is selected from the group consisting of ependymoma posterior fossa group A, kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), or a combination thereof.

[0020] In another preferred embodiment, the tumor includes a tumor with a defective HR repair pathway.

[0021] In another preferred embodiment, the tumor is a primary tumor, a metastatic tumor, a transplanted tumor, or a combination thereof.

[0022] In another preferred embodiment, the ependymoma includes a PFA.

[0023] In another preferred embodiment, the accession number of the CXorf67 gene is Gene ID: 340602.

[0024] In another preferred embodiment, the accession number of the CXorf67 mRNA is NM_203407.3.

[0025] In another preferred embodiment, the accession number of the CXorf67 protein is NP_981952.1.

[0026] In a second aspect of the invention, a pharmaceutical composition is provided, the pharmaceutical composition comprising: a PARP inhibitor, a chemotherapeutic agent, and a pharmaceutically acceptable carrier, diluent, or excipient.

[0027] In another preferred embodiment, the pharmaceutical composition further includes other tumor therapeutic agents.

[0028] In another preferred embodiment, the PARP inhibitor is selected from the group consisting of: Talazoparib, Olaparib, Veliparib, Rucaparib, Niraparib, Fluzoparib, Pamiparib, or combinations thereof; preferably, the PARP inhibitor is selected from: Niraparib.

[0029] In another preferred embodiment, the dose of the PARP inhibitor is 10-100 mg / kg, more preferably 20-80 mg / kg, even more preferably 30-70 mg / kg, and most preferably 50 mg / kg.

[0030] In another preferred embodiment, the chemotherapeutic agent includes drugs that disrupt DNA structure and / or function (such as platinum-based drugs).

[0031] In another preferred embodiment, the chemotherapy drug is a platinum-based drug.

[0032] In another preferred embodiment, the platinum-based drug is selected from the group consisting of Cisplatin, Carboplatin, Nedaplatin, Oxaliplatin, lobaplatin, or combinations thereof; preferably, the platinum-based drug is selected from Carboplatin and / or Cisplatin.

[0033] In another preferred embodiment, the dosage of the platinum-based drug is 0.1-20 mg / kg, more preferably 0.5-10 mg / kg, even more preferably 1-5 mg / kg, and most preferably 2 mg / kg.

[0034] In another preferred embodiment, the PARP inhibitor is Niraparib, and the chemotherapeutic agent is Carboplatin or Cisplatin.

[0035] In a third aspect of the invention, a medicine box is provided, the medicine box comprising:

[0036] (a) A first formulation, wherein the first formulation contains a PARP inhibitor and a pharmaceutically acceptable carrier;

[0037] (b) a second formulation, the second formulation containing a chemotherapy drug and a pharmaceutically acceptable carrier; and

[0038] (c) The instruction manual, which describes a method of using the first and second formulations in combination to treat tumors.

[0039] In another preferred embodiment, the first formulation and the second formulation are independent of each other.

[0040] In another preferred embodiment, the first and second formulations are lyophilized or liquid formulations.

[0041] In another preferred embodiment, the dosage forms of the first and second formulations are injections or gastrointestinal administration formulations.

[0042] In another preferred embodiment, the first formulation is applied before, during, or after the application of the second formulation.

[0043] In a fourth aspect of the invention, there is provided the use of the CXorf67 gene, mRNA, cDNA, or protein, or a detection reagent thereof, for (i) as a biomarker for detecting the sensitivity of tumor cells to PARP inhibitors in combination with chemotherapy; and / or (ii) for preparing diagnostic reagents or kits for detecting the sensitivity of tumor cells to PARP inhibitors in combination with chemotherapy.

[0044] In another preferred embodiment, the diagnostic reagent includes antibodies, primers, probes, sequencing libraries, nucleic acid chips (such as DNA chips), or protein chips.

[0045] In another preferred embodiment, the protein comprises a full-length protein or a protein fragment.

[0046] In another preferred embodiment, the protein contains a PALB2-binding motif.

[0047] In another preferred embodiment, the PALB2 binding motif is located at positions 420-432 of the CXorf67 protein.

[0048] In another preferred embodiment, the CXorf67 gene, mRNA, cDNA, or protein is derived from mammals, preferably rodents (such as mice, rats), primates, and humans, and more preferably from patients diagnosed with tumors that have defects in the HR repair pathway.

[0049] In another preferred embodiment, the detection is a tissue sample detection.

[0050] In another preferred embodiment, the detection includes immunohistochemistry, Western blotting, and quantitative real-time PCR.

[0051] In another preferred embodiment, the detection is to measure tumor tissue.

[0052] In another preferred embodiment, the detection reagent includes a specific antibody against CXorf67, a specific binding molecule against CXorf67, specific amplification primers, a probe, or a chip.

[0053] In another preferred embodiment, the CXorf67 protein or its specific antibody or specific binding molecule is conjugated with or carries a detectable marker.

[0054] In another preferred embodiment, the detectable marker is selected from the group consisting of chromophores, chemiluminescent groups, fluorophores, isotopes, or enzymes.

[0055] In another preferred embodiment, the specific antibody for CXorf67 is a monoclonal antibody or a polyclonal antibody.

[0056] In a fifth aspect of the invention, a diagnostic kit for detecting the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy is provided. The kit comprises a container containing a detection reagent for detecting the CXorf67 gene, mRNA, cDNA, or protein; and a label or instruction manual indicating that the kit is used to detect the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy.

[0057] In another preferred embodiment, the detection reagent for detecting the CXorf67 gene, mRNA, cDNA, or protein includes:

[0058] (a) Specific antibodies against CXorf67 protein; and / or

[0059] (b) Specific primers for specific amplification of CXorf67 mRNA or cDNA.

[0060] In another preferred embodiment, the detection is a tissue sample detection.

[0061] In a sixth aspect of the invention, a method for determining sensitivity to PARP inhibitors combined with chemotherapy is provided, the method comprising:

[0062] a) Provide test samples from the subjects;

[0063] b) Detect the expression level of CXorf67 protein in the test samples; and

[0064] c) Based on the expression level of CXorf67 protein determined in step b), the sensitivity to PARP inhibitor combined with chemotherapy is determined.

[0065] In another preferred embodiment, the presence of CXorf67 protein in the test sample indicates sensitivity to PARP inhibitors combined with chemotherapy.

[0066] In another preferred embodiment, when the expression level of CXorf67 protein in the test sample is >0.5, preferably >1.5, and more preferably >2, it can be determined that the sample is sensitive to PARP inhibitor combined with chemotherapy.

[0067] In another preferred embodiment, the subject is a human or a non-human mammal.

[0068] In another preferred embodiment, the test sample is tumor cells or tissues that express or highly express CXorf67.

[0069] In another preferred embodiment, the test sample is tumor cells or tissue with defects in the HR repair pathway.

[0070] In another preferred embodiment, the detection step (b) includes detecting the amount of CXorf67 mRNA or CXorf67 cDNA; and / or detecting the amount of CXorf67 protein.

[0071] In another preferred embodiment, the expression level of CXorf67 protein in the sample is detected by quantitative real-time PCR or immunohistochemistry.

[0072] In another preferred embodiment, the method is non-diagnostic and non-therapeutic.

[0073] In a seventh aspect of the invention, a method for determining a treatment plan is provided, the method comprising:

[0074] a) Provide test samples from the subjects;

[0075] b) Detect the expression level of CXorf67 protein in the test samples; and

[0076] c) Determine the treatment regimen based on the expression level of CXorf67 protein in the sample.

[0077] In another preferred embodiment, the subject is a human or a non-human mammal.

[0078] In another preferred embodiment, when the sample contains CXorf67 protein (preferably with an expression level of CXorf67 protein > 0.5, more preferably > 1.5, and even more preferably > 2), the treatment regimen includes: CXorf67 inhibitor therapy, PARP inhibitor combined with chemotherapy, or a combination thereof.

[0079] In another preferred embodiment, the drug components used in the CXorf67 inhibitor therapy and the PARP inhibitor combined with chemotherapy are selected from the following groups:

[0080] CXorf67 inhibitor therapy: antibodies, small molecule compounds, microRNA, siRNA, shRNA, or combinations thereof that target and inhibit CXorf67;

[0081] PARP inhibitors in combination with chemotherapy: PARP inhibitors, platinum-based drugs, or combinations thereof.

[0082] In another preferred embodiment, when the subject’s sensitivity to PARP inhibitor combined with chemotherapy is higher than that of the general population (control group), the treatment regimen further includes: CXorf67 inhibitor therapy, PARP inhibitor combined with chemotherapy, or a combination of CXorf67 inhibitor therapy and PARP inhibitor combined with chemotherapy.

[0083] In an eighth aspect of the invention, a method for synergistic killing or inhibition of tumor cells in vitro for non-disease treatment purposes is provided, comprising the steps of: contacting tumor cells with a PARP inhibitor and a chemotherapeutic drug to synergistically kill or inhibit the tumor cells.

[0084] In another preferred embodiment, the tumor cells are tumor cells that express or highly express CXorf67.

[0085] In another preferred embodiment, the chemotherapy drug is a platinum-based drug.

[0086] In another preferred embodiment, the method further includes radiotherapy, targeted therapy, immunotherapy, or a combination thereof on the tumor cells.

[0087] In another preferred embodiment, the radiotherapy includes irradiation.

[0088] In another preferred embodiment, the irradiation includes local irradiation, whole-body irradiation, or a combination thereof.

[0089] In a ninth aspect of the invention, a method for treating a tumor in a subject in need is provided, comprising the steps of administering a therapeutically effective amount of a PARP inhibitor and a chemotherapeutic agent to the subject.

[0090] In another preferred embodiment, the method further includes the step of subjecting the subject to other treatments selected from the group consisting of radiotherapy, surgical treatment, targeted therapy, immunotherapy, or combinations thereof.

[0091] In another preferred embodiment, the tumor is a tumor that expresses or highly expresses CXorf67.

[0092] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here. Attached Figure Description

[0093] Figure 1 This study demonstrated that platinum-based drugs were more sensitive to tumor cells expressing or overexpressing CXorf67. In DaoyCXorf67KO cells, CXorf67 expression was restored, and the cells were treated with different concentrations of Cisplatin or Carboplatin for 5 days. Cell viability was assessed using the CellTiter-Glo kit, and the IC50 of the drugs was calculated. 50 .

[0094] Figure 2 This study demonstrated that platinum-based drugs can increase the sensitivity of PARP inhibitors to CXorf67-expressing or highly expression-positive tumor cells. A. Daoy CXof67-KO cells were transfected with EV and CXof67 lentiviruses, respectively, or PFA-4 primary cells were transfected with sh-GFP and sh-CXorf67 viruses, respectively. The cells were seeded into 96-well plates, and treated the next day with Cisplatin (0.1 μM) or Carboplatin (1 μM), simultaneously with stimulation with different concentrations of Niraparib. After 5 days, CellTiter-Glo was applied, and the values ​​were read using a microplate reader. B. The same cell procedures were repeated. Three days after drug treatment, cells were collected and apoptosis was detected using Annexin-V / PI reagent.

[0095] Figure 3 This study demonstrated that PARP inhibitors can increase the sensitivity of platinum-based drugs to CXorf67-expressing or highly expressed tumor cells. A. Daoy CXof67-KO cells were transfected with EV and CXof67 lentiviruses, respectively. After 72 hours of culture, the cells were seeded into 96-well plates. The next day, the cells were treated with DMSO or Niraparib (1 μM) and stimulated with different concentrations of Cisplatin. After 5 days, CellTiter-Glo was applied, and the values ​​were read using a microplate reader. B. PFA-4 primary cells were transfected with sh-GFP and sh-CXorf67 viruses, respectively. After 60 hours, the cells were seeded into 96-well plates, and the above drug treatment procedures were repeated. Cell viability was then assessed.

[0096] Figure 4 This study demonstrated that PARP inhibitors combined with platinum-based drugs can inhibit the growth of tumors expressing or overexpressing CXorf67. A. Stable Luciferase-expressing C67-KO and C67-KO-replenished CXorf67Daoy cells were constructed and injected into the cerebellum of nude mice. After 7 days, the mice were randomly divided into four groups and treated with Vehicle, Cisplatin, Niraparib, and Cisplatin combined with Niraparib. Tumor size was measured every 7 days. B. The constructed PFA-4 PDX model was expanded and randomly divided into four groups of five mice each, receiving the same treatment with the above drugs. Tumor volume and size were measured every 7 days. When the tumor volume reached 800 mm², the tumor growth was recorded. 3 At that time, the mice were euthanized, and the survival curves were statistically analyzed. Detailed Implementation

[0097] Through extensive and in-depth research and numerous screenings, the inventors unexpectedly discovered for the first time that tumor cell lines or tumor tissues expressing or highly expressing CXorf67 are more sensitive to PARP inhibitors combined with chemotherapy (such as PARP inhibitors combined with platinum-based drugs). Therefore, the CXorf67 gene or its protein can be used as a biomarker for detecting the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy. Based on this, the inventors completed this invention.

[0098] the term

[0099] To facilitate understanding of the invention, certain technical and scientific terms are specifically defined below. Unless otherwise expressly defined herein, all other technical and scientific terms used herein have the meanings commonly understood by one of ordinary skill in the art to which this invention pertains. Before describing the invention, it should be understood that the invention is not limited to the specific methods and experimental conditions described, as such methods and conditions can vary. It should also be understood that the terminology used herein is intended only to describe particular embodiments and is not intended to be restrictive; the scope of the invention will be limited only by the appended claims.

[0100] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. As used herein, when referring to a specifically enumerated numerical value, the term “about” means that the value can vary from the enumerated value by no more than 1%. For example, as used herein, the expression “about 100” includes all values ​​between 99 and 101 (e.g., 99.1, 99.2, 99.3, 99.4, etc.).

[0101] As used herein, the term "treatment" refers to administering an oral or topical therapeutic agent to a patient who has one or more symptoms of a disease, and the therapeutic agent is known to have a therapeutic effect on these symptoms. Typically, the therapeutic agent is administered to the patient in an amount that effectively relieves the symptoms of one or more diseases (therapeutic effective amount).

[0102] Tumors with deficient HR repair pathway

[0103] Homologous recombination (HR) repair pathway is a fault-free repair process that primarily utilizes homologous DNA within the cell as a template to repair broken DNA during the S / G2 phase of the cell cycle. Defects or deficiencies in HR can lead to genomic instability, subsequently contributing to tumor development and progression. For example, mutations in genes such as BRCA1, PLAB2, and BRCA2 within the HR pathway have been found in many tumors. These mutations can prevent the effective repair of DNA double-strand breaks, causing alterations, rearrangements, and mutations in cellular gene copy numbers, ultimately leading to tumors and diseases such as ovarian cancer, breast cancer, pancreatic cancer, and prostate cancer.

[0104] In a preferred embodiment, the tumor with a defective HR repair pathway is a tumor that expresses or highly expresses CXorf67, selected from the following group: ependymoma posterior fossa group A, kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), or a combination thereof.

[0105] Ependymoma (EPN) is a malignant neuroepithelial tumor that occurs in the central nervous system (CNS) and can occur in both children and adults. EPN primarily occurs in three locations: supratentorial (ST), posterior fossa (PF), and spinal (SP). A 2015 study further classified ependymomas in these three locations into molecular subtypes using DNA methylation analysis: ST includes ST-SE, ST-EPN-YAP1, and ST-EPN-RELA; PF includes PF-SE, PFA, and PFB; and SP includes SP-SE, SP-MPE, and SP-EPN. PFA mainly occurs in infants and young children (mean age 3 years, range 0-51 years) and has a poor prognosis; PFB mainly occurs in adolescents (mean age 30 years, range 10-65 years) and has a better prognosis. The PFA subtype of ependymoma mainly occurs in the posterior part of the brain in children, and has a poor prognosis. Currently, treatment mainly involves surgery and radiotherapy, with a lack of effective drug therapy.

[0106] sample

[0107] As used herein, the term "sample" or "sample" refers to material specifically associated with a subject from which specific information relating to the subject can be determined, calculated, or inferred. A sample may consist wholly or partially of biological material from the subject. A sample may also be material that has been in contact with the subject in a manner that allows testing of the sample to provide information relating to the subject. A sample may also be material that has been in contact with other materials, not belonging to the subject, but which enable subsequent testing of the first material to determine information relating to the subject; for example, a sample may be a cleaning solution for a probe or scalpel. A sample may be a source of biological material other than that in contact with the subject, as long as those skilled in the art can still determine information relating to the subject from the sample.

[0108] Express

[0109] As used herein, the term "expression" includes the production of mRNA from a gene or gene segment, and includes the production of proteins encoded by RNA or a gene or gene segment, as well as the appearance of detection substances associated with expression. For example, the binding of cDNA, ligand-binding ligands (such as antibodies) to genes or other oligonucleotides, proteins, or protein fragments, and the chromogenic portion of the ligand-binding ligand are all included within the scope of the term "expression." Therefore, an increase in the density of the upper half-spot in immunoblotting such as Western blotting also falls within the scope of the biologically molecular-based term "expression."

[0110] Reference value

[0111] As used herein, the term "reference value" refers to a value that is statistically relevant to a particular outcome when compared with the results of an analysis. In a preferred embodiment, the reference value is determined based on a statistical analysis of studies comparing CXorf67 expression with known clinical outcomes. Some such studies are shown in the Examples section of this document. However, studies from the literature and user experience with the methods disclosed herein can also be used to produce or adjust reference values. Reference values ​​can also be determined by considering circumstances and outcomes that are particularly relevant to the patient's medical history, genetics, age, and other factors.

[0112] In this invention, the reference value refers to the cut-off value, which refers to the expression level of CXorf67 in tumor cells or tissues with defects in the HR repair pathway. Preferably, the expression level of CXorf67 is >0.5, more preferably >1.5, and even more preferably >2.

[0113] Samples of non-tumor cells

[0114] As used in this article, the term "sample of non-tumor cells" includes, but is not limited to, individuals with tumors that do not have defects in the HR repair pathway.

[0115] CXorf67 protein and polynucleotides

[0116] In this invention, the terms "inventive protein," "CXorf67 protein," and "CXorf67 polypeptide" are used interchangeably and all refer to proteins or polypeptides having the CXorf67 amino acid sequence. These include CXorf67 proteins with or without a starting methionine. Furthermore, the term also includes full-length CXorf67 and fragments thereof. The CXorf67 protein referred to in this invention includes its complete amino acid sequence, its secreted protein, its mutants, and its functionally active fragments.

[0117] CXorf67 (chromosome X open reading frame 67) is located at Xp11.22 on chromosome 67. It has one exon and no introns, encoding 503 amino acids. CXorf67 is a protein of unknown function, primarily located in the nucleus. Based on website predictions, it lacks known domains and is mostly disordered.

[0118] The human CXorf67 protein is 503 amino acids long (accession number NP_981952.1, ACCESSION:NP_981952XP_291352, VERSION:NP_981952.1). The mouse CXorf67 protein is 589 amino acids long (accession number NP_001159905.1, ACCESSION:NP_001159905, VERSION:NP_001159905.1).

[0119] In this invention, the terms "CXorf67 gene" and "CXorf67 polynucleotide" are used interchangeably and both refer to nucleic acid sequences having the CXorf67 nucleotide sequence.

[0120] The full-length genome of the human CXorf67 gene is 1896 bp (NCBI GenBank accession number: Gene ID: 340602), and the full-length mRNA sequence of its transcription product is 1512 bp (NCBI GenBank accession number: NM_203407.3).

[0121] The full-length genome of the mouse CXorf67 gene is 2203 bp (NCBI GenBank accession number Gene ID: 102991), and the full-length mRNA sequence of its transcription product is 1770 bp (NCBI GenBank accession number NM_001166433.1).

[0122] The DNA similarity between humans and mice with CXorf67 is 39%, and the protein sequence similarity is also 39%.

[0123] It should be understood that nucleotide substitutions in a codon are acceptable when encoding the same amino acid. Furthermore, it should be understood that nucleotide substitutions are also acceptable when they result in conserved amino acid substitutions.

[0124] Having obtained the amino acid fragment of CXorf67, the nucleic acid sequence encoding it can be constructed, and specific probes can be designed based on the nucleotide sequence. The full-length nucleotide sequence or its fragments can typically be obtained using PCR amplification, recombinant methods, or artificial synthesis. For PCR amplification, primers can be designed based on the CXorf67 nucleotide sequence disclosed in this invention, especially the open reading frame sequence, and the relevant sequence can be amplified using a commercially available cDNA library or a cDNA library prepared according to conventional methods known to those skilled in the art. When the sequence is long, two or more PCR amplifications are often required, and then the fragments amplified from each amplification are spliced ​​together in the correct order.

[0125] Once the relevant sequence is obtained, it can be obtained in large quantities using recombination methods. This typically involves cloning it into a vector, transferring it into cells, and then isolating the sequence from the proliferated host cells using conventional methods.

[0126] In addition, sequences can be synthesized artificially, especially when the fragment length is short. Typically, long sequences can be obtained by first synthesizing multiple small fragments and then joining them.

[0127] Currently, the DNA sequence encoding the protein of this invention (or its fragments, derivatives) can be obtained entirely through chemical synthesis. This DNA sequence can then be introduced into various existing DNA molecules (such as vectors) and cells known in the art.

[0128] PARP inhibitors

[0129] In 2005, two laboratories simultaneously reported that PARP inhibitors could selectively kill BRCA1 / 2 mutated tumor cells. Subsequent studies found that tumor cells with BRCAness (containing HR deficiency but not BRCA1 / 2 mutations) were also sensitive to PARP inhibitors. Early understanding of the mechanism of action of PARP inhibitors suggested that their addition leads to defects in single-strand break repair. After a round of DNA replication, single-strand breaks become double-strand breaks. Normal cells, possessing a complete HR repair pathway, survive; while cells with HR repair defects die because they cannot repair. However, further research revealed that while various PARP inhibitors have comparable inhibitory efficiency on PARP catalytic activity, their cell-killing effects vary significantly. Why does this happen? It is currently believed that in addition to inhibiting its catalytic function, PARP inhibitors can also bind (trapping) the PARP protein to DNA, preventing it from detaching and blocking replication, thus accelerating the formation of DNA double-strand breaks. It is precisely this difference in trapping ability that leads to different PARP inhibitory effects.

[0130] Currently, several PARP inhibitors have been approved for clinical treatment. For example, Olaparib, Rucaparib, Niraparib, and Talazoparib from abroad, as well as Fluzoparib and Pamiparib from China, have been approved for the treatment of BRCA-mutated ovarian cancer and breast cancer.

[0131] Currently, Niraparib and Pamiparib have been found to cross the blood-brain barrier (BBB) ​​relatively well, and Olaparib has also been reported to cross the BBB in brain tumor patients. However, some argue that the BBB integrity of brain tumor patients is already compromised, so the BBB is irrelevant. Current progress in neuro-oncology is largely focused on preclinical and clinical research, and no PARP inhibitors have yet been approved. Besides developing new PARP inhibitors, many studies are expanding their indications, such as identifying new biomarkers and combination therapies. In fact, many CNS tumors rarely have HR gene mutations, but some biomarkers that indirectly cause BRCAness have been discovered. For example, the inventors previously discovered that the expression or high expression of CXorf67 can inhibit HR repair, thereby increasing PARP inhibitor sensitivity.

[0132] Typically, the PARP inhibitors of the present invention are selected from the group consisting of: Talazoparib, Olaparib, Veliparib, Rucaparib, Niraparib, Fluzoparib, Pamiparib, or combinations thereof.

[0133] In this invention, the inventors, through extensive screening, unexpectedly discovered for the first time that tumor cell lines or tumor tissues expressing or overexpressing CXorf67 are more sensitive to PARP inhibitors combined with chemotherapy (such as PARP inhibitors combined with platinum-based drugs). Therefore, the CXorf67 gene or its protein can be used as a biomarker to detect the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy. Furthermore, PARP inhibitors combined with platinum-based drugs also have a synergistic therapeutic effect on tumor cell lines or tumor tissues expressing or overexpressing CXorf67. Based on this, the inventors completed this invention.

[0134] Platinum-based drugs

[0135] Platinum-based drugs work by halting DNA replication in tumor cells and preventing cell division. When platinum-based drugs enter tumor cells, they hydrolyze into hydrates. These hydrates are further deprotonated to generate hydroxylated coordination ions. These ions are highly reactive and, in vivo, form a closed five-membered chelate ring with the two guanine bases at the N27 position of DNA. This disrupts the hydrogen bonds between the purine and cytosine groups on the two polynucleotide chains, disturbing the normal double helix structure of DNA, causing local denaturation and inactivation, and thus eliminating its replication ability, thereby achieving an anti-cancer effect.

[0136] Typically, the platinum-based drugs of the present invention are selected from the group consisting of: Cisplatin, Carboplatin, Nedaplatin, Oxaliplatin, lobaplatin, or combinations thereof.

[0137] In this invention, the inventors unexpectedly discovered that platinum-based drugs and PARP inhibitors have a synergistic effect.

[0138] Pharmaceutical compositions or combinations of active ingredients and their uses

[0139] The present invention also provides a pharmaceutical composition for synergistic treatment of CXorf67-expressing or highly expressed tumors, wherein the pharmaceutical composition comprises: a PARP inhibitor, a chemotherapeutic agent, and a pharmaceutically acceptable carrier, diluent, or excipient.

[0140] The present invention also provides the use of a combination of active ingredients for preparing a drug or formulation for treating CXorf67-expressing or highly expressing tumors, or for synergistically treating CXorf67-expressing or highly expressing tumors, wherein the combination of active ingredients comprises: (Z1) a first active ingredient: a PARP inhibitor; and (Z2) a second active ingredient: a chemotherapeutic drug. Preferably, the drug or formulation further comprises other tumor therapeutic agents, or pharmaceutically acceptable carriers, diluents, or excipients.

[0141] Preferably, the drug, preparation, or drug composition may also be used in combination with other treatment methods selected from the group consisting of radiotherapy, surgical treatment, targeted therapy, immunotherapy, or combinations thereof.

[0142] Typically, the PARP inhibitor is selected from the group consisting of: talazoparib, olaparib, veliparib, rucaparib, niraparib, fluzoparib, pamiparib, or combinations thereof; the chemotherapy drug is a platinum-based drug selected from the group consisting of: cisplatin, carboplatin, nedaplatin, oxaliplatin, lobaplatin, or combinations thereof.

[0143] Typically, the CXorf67-expressing or highly expressing tumors include tumors with defective HR repair pathways, which can be primary tumors and / or metastatic tumors, selected from the following group: ependymoma posterior fossa group A, kidney renal clear cell carcinoma (KIRC), kidney renal papillary cell carcinoma (KIRP), or combinations thereof; wherein the ependymoma includes PFA type.

[0144] Detection methods

[0145] Taking advantage of the fact that CXorf67 is present in tumor cells or tissues (such as tumors with defective HR repair pathways, preferably ependymoma) and is closely related to the sensitivity of PARP inhibitors in combination with chemotherapy, this invention also provides a method for detecting the sensitivity of tumor cells to PARP inhibitors in combination with chemotherapy.

[0146] In a preferred embodiment of the present invention, the present invention provides a high-throughput next-generation sequencing method for detecting CXorf67, as well as Sanger sequencing, quantitative PCR (qPCR), in situ immunofluorescence assay (FISH), and immunohistochemistry.

[0147] Test kit

[0148] Based on the correlation between tumor cells expressing or overexpressing CXorf67 and their sensitivity to PARP inhibitors combined with chemotherapy, i.e., tumor cells expressing or overexpressing CXorf67 are more sensitive to PARP inhibitors combined with chemotherapy, CXorf67 can be used as a biomarker to guide the use of PARP inhibitors combined with chemotherapy.

[0149] The present invention also provides a diagnostic kit for detecting the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy, comprising a detection reagent for detecting the CXorf67 gene, mRNA, cDNA, or protein; and a label or instruction manual indicating that the kit is used to detect the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy.

[0150] Detection methods and kits

[0151] This invention relates to diagnostic assays for the quantitative and localized detection of human CXorf67 protein or mRNA levels. These assays are well known in the art. The human CXorf67 protein levels detected in these assays can be used to assess the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy.

[0152] One method for detecting the presence of CXorf67 protein in a sample is to use a specific antibody against CXorf67 protein. The method includes: contacting the sample with the CXorf67 protein-specific antibody; observing whether an antibody complex is formed. The formation of an antibody complex indicates the presence of CXorf67 protein in the sample.

[0153] CXorf67 protein or its polynucleotides can be used for the diagnosis and treatment of CXorf67 protein-related diseases. Part or all of the polynucleotides of this invention can be immobilized as probes on microarrays or DNA chips for differential gene expression analysis and gene diagnosis in tissues. Anti-CXorf67 antibodies can be immobilized on protein chips for the detection of CXorf67 protein in samples.

[0154] The main advantages of this invention include:

[0155] 1) The inventors have for the first time discovered that the CXorf67 gene, mRNA, cDNA or protein or its detection reagents can be used as biomarkers to detect the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy.

[0156] 2) The inventors have discovered for the first time that the CXorf67 gene, mRNA, cDNA or protein or its detection reagents can also be used to prepare diagnostic reagents or kits for detecting the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy.

[0157] 3) The inventors discovered for the first time that platinum-based drugs can increase the sensitivity of PARP inhibitors to CXorf67-expressing or highly expressed tumor cells.

[0158] 4) The inventors discovered for the first time that PARP inhibitors can increase the sensitivity of platinum-based drugs to CXorf67-expressing or highly expressed tumor cells.

[0159] 5) The inventors discovered for the first time that PARP inhibitors combined with platinum-based drugs can inhibit the growth of tumors expressing or overexpressing CXorf67.

[0160] 6) The inventors discovered for the first time that PARP inhibitors combined with chemotherapy (such as platinum-based drugs) have a synergistic killing effect on tumor cells that express or overexpress CXorf67.

[0161] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions, such as those described in Sambrook et al., Molecular Cloning: A Laboratory Manual (New York: Cold Spring Harbor Laboratory Press, 1989), or as recommended by the manufacturer. Unless otherwise stated, percentages and parts are weight percentages and parts by weight.

[0162] Experimental materials

[0163] The Daoy cell line was obtained from the stem cell bank of the Chinese Academy of Sciences and cultured in MEM medium (with 10% FBS, non-essential amino acids, GlutaMAX and Sodium pyruvate).

[0164] The CXorf67-KO Daoy cell line was constructed using CRISPR-Cas9 technology.

[0165] Primary PFA-type ependymoma cells were obtained from PDX tumor isolation and culture in this experiment, and were cultured using Neurobasal medium (with added B2, N2, GLUTAMAX, EGF, FGF, and heparin). All cells were cultured in an incubator at 37°C with 5% CO2.

[0166] Niraparib (HY-10619), Cisplatin (HY-17394), and Carboplatin (HY-17393) were purchased from MCE. CXorf67-shRNA and GFP-shRNA plasmids were constructed using the pLKO.1 vector. CXorf67 (HPA004003) antibody was purchased from Sigma-Aldrich. GAPDH (10494-1-AP) antibody was purchased from Proteintech. The FITC Annexin V apoptosis detection kit (#556547) was purchased from BD.

[0167] General Method

[0168] 1. Cell survival experiment

[0169] (1) In testing the effect of CXorf67 on the sensitivity of platinum-based drugs (Cisplatin and Carboplatin), Daoy cells with CXorf67-KO and KO-replenished CXorf67 were seeded into 96-well plates. On the second day, different concentrations of Cisplatin and Carboplatin were added, and the cells were cultured for another five days, with additional culture medium and drugs added as needed. On the fifth day, 50 μl of CellTiter-Glo reagent was added, and the cells were lysed at room temperature for 20 minutes. The fluorescence values ​​were then read using a microplate reader.

[0170] (2) In the sensitivity test of platinum-based drugs and the PARP inhibitor (Niraparib) on CXorf67-expressing or highly expression tumor cells, Daoy cells with CXorf67-KO and KO-replenished CXorf67 were also seeded in 96-well plates. On the second day, different concentrations of Niraparib were added, along with Cisplatin (0.1 μM) or Carboplatin (1 μM); or different concentrations of Cisplatin were added, along with Niraparib (1 μM). After culturing for 5 days, cell viability was measured as described above. For primary cells derived from PDX, CXorf67 was knocked down (sh-CXorf67), with sh-GFP as a control, and then seeded in 96-well plates. Subsequent cell treatment and viability measurements were performed using different concentrations of Niraparib combined with platinum-based drugs, or different concentrations of Cisplatin combined with Niraparib.

[0171] 2. Apoptosis experiment

[0172] Daoy CXorf67-KO cell lines were cultured, then infected with CXorf67-overexpressing lentivirus. After selection, the cells were stably cultured for 2-3 passages. KO and CXorf67-filled cells were then seeded into 96-well plates. The next day, cells were treated with Niraparib (0.5 μM), Cisplatin (0.1 μM), and Carboplatin (1 μM) individually, or with a combination of Niraparib and Cisplatin, or Niraparib and Carboplatin. After 3 days of continued culture, cells were digested and collected. Cells were washed twice with binding buffer from the Annexin-V / PI kit, then incubated with FITC-Annexin and PI at room temperature for 15 minutes. Subsequent analysis was performed using flow cytometry.

[0173] 3. Orthotopic tumor transplantation experiment in mouse brain

[0174] All mouse experiments and procedures were approved by the Animal Ethics Committee of the Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences. Six-week-old female nude mice were purchased from Shanghai Silex Company and housed in an SPF-grade environment.

[0175] Daoy cells containing the constructed CXorf67-KO and KO-replenished CXorf67 were transfected with Luciferase lentivirus. After screening for stable expression cell lines, 2×10⁶ cells were transfected with Luciferase lentivirus. 5 Tumor cells were injected into the cerebellum of nude mice (2 mm below the lambda line, 1 mm to the right of the midline, 3 mm depth). Tumor formation was then determined using in vivo imaging. Mice were randomly divided into four groups: control group, Niraparib (50 mg / kg) group, Cisplatin (2 mg / kg) group, and Niraparib combined with Cisplatin group. Cisplatin, dissolved in saline, was administered intraperitoneally once a week. Niraparib, dissolved in 0.5% methylcellulose, was administered by gavage five times a week. Tumor size was subsequently assessed every seven days using IVIS SpectrumCT imaging. Each mouse was injected with 200 μl of D-luciferin substrate (15 mg / ml), and the tumor was detected ten minutes later. Signal intensity was then calculated using software.

[0176] 4. Subcutaneous xenograft experiment in mice

[0177] The PFA-4 model of PFA-type ependymoma, previously established in the laboratory, was expanded and passaged subcutaneously in nude mice. The resulting tumor cells were digested into single cells and counted. Cells (3 × 10⁻⁶) were then divided into groups. 6 (Each mouse) was mixed with Matrigel at a 1:1 ratio and subcutaneously injected into 7-week-old female nude mice. Tumors were cultured until they reached a size of 100 mm². 3 At approximately 10:00 AM, mice were randomly divided into four groups: a control group, a Niraparib (50 mg / kg) group, a Cisplatin (2 mg / kg) group, and a Niraparib combined with Cisplatin group. Cisplatin was dissolved in physiological saline and administered intraperitoneally once a week. Niraparib was dissolved in 0.5% methylcellulose and administered by gavage five times a week. Mouse body weight and tumor volume were measured weekly and calculated using the formula (length * width * width) / 2.

[0178] Example 1. Tumor cells expressing CXorf67 are more sensitive to platinum-based drugs.

[0179] First, CXorf67 expression was restored in Daoy CXorf67KO cells. On the second day, different concentrations of Cisplatin or Carboplatin were added for 5 days, and cell viability was detected using the CellTiter-Glo kit.

[0180] like Figure 1 As shown, tumor cells expressing CXorf67 were found to be more sensitive to Cisplatin and Carboplatin.

[0181] Example 2. Platinum-based drugs can increase the sensitivity of PARP inhibitors to tumor cells expressing CXorf67.

[0182] As the data from Example 1 showed, platinum-based drugs alone can increase the sensitivity of CXof67 expressing cells to drugs. In this example, we will further explore whether platinum-based drugs can increase the sensitivity to PARP inhibitors.

[0183] The inventors first replenished CXof67 in Daoy-CXof67KO cells, then treated them with Cisplatin and Carboplatin respectively, while adding different concentrations of Niraparib for 5 days, and tested cell viability using Celltiter-Glo.

[0184] like Figure 2 As shown in Figure A, Cisplatin or Carboplatin did indeed significantly increase the inhibitory effect of PARP inhibitors on cells expressing CXof67.

[0185] Secondly, the inventors also conducted a CXof67 knockdown experiment in tumor cells derived from PFA-type ependymoma.

[0186] like Figure 2 As shown in Figure A, contrary to the overexpression experiment, knocking down CXof67 can significantly inhibit the sensitizing effect of Cisplatin or Carboplatin on PARP inhibitors.

[0187] In addition, the inventors used the Annexin-V / PI kit to test the killing effects of Cisplatin and Carboplatin in combination with PARP inhibitors on cells with and without CXorf67.

[0188] like Figure 2 As shown in B, the proportion of apoptosis was also found to be significantly increased in the combination treatment groups (i.e., Niraparib + Carboplatin; Niraparib + Cisplatin) compared to the single treatment groups (i.e., Niraparib, Carboplatin, and Cisplatin were used alone).

[0189] The above results confirm that platinum-based drugs can increase the sensitivity of PARP inhibitors (such as Niraparib) to tumor cells expressing CXorf67, and the combination of the two is significantly more effective than the use of either alone.

[0190] Example 3. PARP inhibitors can increase the sensitivity of platinum-based drugs to tumor cells expressing CXorf67.

[0191] In Example 2, it was verified that platinum-based drugs can increase the sensitivity of PARP inhibitors to CXorf67-expressing or highly expression-containing tumor cells. In this example, we will further investigate whether PARP inhibitors can increase the sensitivity to platinum-based drugs.

[0192] The inventors also first reintroduced CXof67 into Daoy cells containing CXof67KO, treated them with different concentrations of Cisplatin, and treated them with 1 μM Niraparib or DMSO for 5 days, and then tested cell viability using Celltiter-Glo.

[0193] like Figure 3 As shown in Figure A, Niraparib was found to reduce the IC50 of Cisplatin in cells replenished with CXorf67. 50 The decrease from 451 nM to 62.52 nM did significantly increase the sensitivity of Cisplatin.

[0194] In addition, the inventors tested the effect of Niraparib on Cislatin sensitivity in CXorf67-knockdown PFA-4PDX-derived primary tumor cells.

[0195] like Figure 3 As shown in Figure B, consistent with the previous results, the IC50 of Cislatin can be significantly reduced in the presence of CXorf67 expression. 50 However, when CXorf67 was knocked down, the synergistic effect was significantly weakened.

[0196] The above results confirm that PARP inhibitors can increase the sensitivity of platinum-based drugs to CXorf67-expressing or highly expressed tumor cells, and the combination of the two is significantly more effective than the use of either drug alone.

[0197] Example 4. PARP inhibitors combined with platinum-based drugs can inhibit the growth of tumors expressing CXorf67.

[0198] To verify whether platinum-based drugs and PARP inhibitors have a synergistic effect in vivo, the inventors first constructed stable Luciferase cell lines from Daoy C67-KO and KO cells replenished with CXorf67. The cells were injected into the cerebellum of immunodeficient mice, and tumor formation was assessed after approximately 7 days. The mice were then randomly divided into four groups: ① Vehicle (empty vector); ② Cisplatin (2 mg / kg, intraperitoneal injection, once a week); ③ Niraparib (50 mg / kg, gavage, five times a week); and ④ Niraparib (50 mg / kg, gavage, five times a week) + Cisplatin (2 mg / kg, intraperitoneal injection, once a week). Tumor size was assessed weekly using in vivo imaging after drug administration.

[0199] like Figure 4 As shown in Figure A, the results indicate that both Niraparib and Cisplatin can reduce tumor volume (especially CXorf67-expressing or highly expressing tumors), and the combination of Niraparib and Cisplatin can significantly inhibit tumor formation.

[0200] Furthermore, the same assay was performed on a PDX model derived from PFA-type ependymoma patients. PFA-4 cells were mixed with Matrigel 1:1 and injected subcutaneously into BALB / c nude mice (3 × 10⁻⁶ cells / mL). 6 Cells / animal), 5 animals per group, when the tumor volume reaches 100mm 3 At approximately 10:00 AM, mice were administered ① Vehicle; ② Cisplatin (2 mg / kg, intraperitoneal injection, once a week); ③ Niraparib (50 mg / kg, gavage, five times a week); and ④ Niraparib (50 mg / kg, gavage, five times a week) + Cisplatin (2 mg / kg, intraperitoneal injection, once a week), respectively. Tumor volume and mouse weight were measured weekly.

[0201] like Figure 4 As shown in Figure B, the results showed that both Niraparib and Cisplatin could reduce the volume of tumors (especially those expressing or overexpressing CXorf67), and the combination of the two could significantly inhibit tumor growth, exhibiting a synergistic effect.

[0202] The specific experimental data for the above results are shown in Tables 1-4:

[0203] Table 1

[0204]

[0205] Table 2

[0206]

[0207] Table 3

[0208]

[0209] Table 4

[0210]

[0211]

[0212] After calculating the average of the data in Tables 1-4, the data are summarized in Table 5:

[0213] Table 5

[0214]

[0215] According to the data in Table 5, when 36 days after treatment, Z3 > Z1 + Z2 (i.e., 739.3354 > 426.0953 + 262.4895), which indicates that the reduction in tumor volume when Niraparib and Cisplatin are used together exceeds the sum of the reductions in tumor volume when Niraparib and Cisplatin are used alone.

[0216] The above analysis shows that PARP inhibitors and chemotherapy (including platinum-based drugs) have a synergistic killing effect on tumor cells that express or highly express CXorf67.

[0217] All documents mentioned in this invention are incorporated herein by reference as if each document were individually incorporated by reference. Furthermore, it should be understood that after reading the foregoing teachings of this invention, those skilled in the art can make various alterations or modifications to this invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0218] discuss

[0219] CXorf67 is located at p11.22 on the X chromosome, contains only one exon and no introns, and its CDS (coding sequence) is 1512 bp long, encoding 503 amino acids. Our laboratory work in 2020 discovered another function of CXorf67: it can influence the efficiency of homologous recombination (HR) repair by regulating the binding of PALB2 and BRCA2.

[0220] The PARP (poly(ADP-ribose) polymerase) family currently has 17 members, mainly located in the nucleus, and contains a common ART (ADP-ribosyltransferase) catalytic motif for PARylation modification. PARP1 is the most extensively studied member. As a DNA damage sensing protein, it can use NAD+ to attach negatively charged PAR to DNA damage repair proteins to transmit repair signals. Early studies found that PARP1 plays a role in single-strand break and base excision repair, and recent studies have shown that it also plays an important role in nucleic acid excision, mismatch, and homologous recombination repair.

[0221] Double-strand breaks (DSBs) are one of the most serious types of DNA damage faced by cells. DNA double-strand break repair is generally classified into two types based on the involvement of homologous sequences. One is classical non-homologous end joining (cNHEJ), which is independent of homologous sequences and mainly functions during the G0 / G1 phase of the cell cycle. The other is the homologous recombination (HR) repair pathway, a fault-free repair method that primarily uses homologous DNA within the cell as a template to repair broken DNA during the S / G2 phase of the cell cycle. This homologous DNA can be sequences from sister chromatids, homologous chromosomes, or translocations.

[0222] Tumors with deficient HR repair pathways are sensitive to PARP inhibitors. When PARP inhibitors block DNA single-strand break repair, DNA undergoes replication, transforming single-strand breaks into double-strand breaks. HR repair deficiency in tumor cells leads to cell death; normal cells, however, have intact HR repair and are not killed. The inventors' previous results showed that CXorf67 expression or high expression can inhibit DNA homologous recombination repair by competitively binding to PALB2 with BRCA2, and they proposed for the first time that CXorf67 can serve as a biomarker for PARP inhibitor use in tumor cells. Furthermore, the inventors found that PARP inhibitors combined with radiotherapy can more effectively kill tumor cells expressing or highly expressing CXorf67. However, the efficacy of combining PARP inhibitors with other treatments remains unclear, and how to further efficiently kill tumors with deficient HR repair pathways remains unknown.

[0223] Based on the aforementioned needs, in this invention, the inventors, through extensive screening, unexpectedly discovered for the first time that tumor cell lines or tumor tissues expressing or overexpressing CXorf67 are more sensitive to PARP inhibitors combined with chemotherapy (such as PARP inhibitors combined with platinum-based drugs). Therefore, the CXorf67 gene or its protein can be used as a biomarker to detect the sensitivity of tumor cells to PARP inhibitors combined with chemotherapy. Furthermore, PARP inhibitors combined with platinum-based drugs also exhibit a synergistic killing effect on tumor cell lines or tumor tissues expressing or overexpressing CXorf67. Based on this, this invention provides a more sensitive and effective treatment method for tumors with deficient HR repair pathways.

Claims

1. Use of a combination of active ingredients, characterized in that, The combination of active ingredients is used to prepare a drug or formulation for treating tumors expressing or overexpressing CXorf67, or for synergistically treating tumors expressing or overexpressing CXorf67, wherein the combination of active ingredients comprises the following components: (Z1) First active ingredient: PARP inhibitor, wherein the PARP inhibitor is Niraparib; and (Z2) Second active ingredient: Chemotherapy drug, wherein the chemotherapy drug is a platinum-based drug selected from: Carboplatin and / or Cisplatin; The tumors expressing or highly expressing CXorf67 are ependymomas.

2. Use according to claim 1, characterized in that, The drug or formulation may also include a pharmaceutically acceptable carrier.

3. Use according to claim 1, characterized in that, The tumor is a primary tumor, a metastatic tumor, a transplanted tumor, or a combination thereof.

4. A pharmaceutical composition for treating ependymoma, characterized by, The pharmaceutical composition comprises the following components: a PARP inhibitor, a chemotherapeutic agent, and a pharmaceutically acceptable carrier; The PARP inhibitor is Niraparib; The chemotherapy drug is a platinum-based drug, and the platinum-based drug is selected from: Carboplatin and / or Cisplatin.

5. The pharmaceutical composition of claim 4, wherein The dosage of the PARP inhibitor is 10-100 mg / kg.

6. The pharmaceutical composition of claim 4, wherein The dosage of the PARP inhibitor is 20-80 mg / kg.

7. The pharmaceutical composition of claim 4, wherein The dosage of the PARP inhibitor is 30-70 mg / kg.

8. The pharmaceutical composition of claim 4, wherein The dosage of the PARP inhibitor is 50 mg / kg.

9. The pharmaceutical composition of claim 4, wherein The dosage of the platinum-based drugs is 0.1-20 mg / kg.

10. The pharmaceutical composition according to claim 4, wherein The dosage of the platinum-based drugs is 0.5-10 mg / kg.

11. The pharmaceutical composition according to claim 4, wherein The dosage of the platinum-based drugs is 1-5 mg / kg.

12. The pharmaceutical composition of claim 4, wherein The dosage of the platinum-based drug is 2 mg / kg.

13. A medicine box, characterized in that, The medicine box consists of the following parts: (a) A first formulation, the first formulation comprising a PARP inhibitor and a pharmaceutically acceptable carrier, wherein the PARP inhibitor is Niraparib; (b) A second formulation comprising a chemotherapeutic agent and a pharmaceutically acceptable carrier, wherein the chemotherapeutic agent is a platinum-based drug selected from: Carboplatin and / or Cisplatin; and (c) The instruction manual, which describes a method of using the first and second formulations in combination to treat ependymoma.

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