Kidney cancer sunitinib drug resistance diagnostic marker and application thereof

Abstract

The invention discloses a diagnostic marker for the drug resistance of kidney cancer sunitinib. The diagnostic marker for the drug resistance of kidney cancer sunitinib is selected from a group consisting of histone acetyltransferase KAT2A. The invention further discloses a kit for detecting the sunitinib drug resistance of the kidney cancer. The kit comprises a reagent for detecting the expression quantity of KAT2A. The KAT2A provided by the invention is used as a renal cancer sunitinib drug resistance diagnosis marker, has good specificity and high sensitivity, provides a new diagnosis and treatment means for renal cancer sunitinib drug resistance, is beneficial to drug resistance monitoring and avoids further invalid treatment, and has a good medical conversion prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of biological medicine and diagnosis, and particularly relates to a diagnosis marker for sunitinib-resistant renal cancer and application thereof. BACKGROUND

[0002] The information disclosed in this Background section is for the purpose of providing an overview of some of the background art only and is not intended to be nor should it be taken as admitting that such information in any way constitutes prior art to the present application.

[0003] Renal cancer is one of the most common cancers in adults. According to the data published on the website of the American Cancer Society, there are expected to be 81610 new cases and 14390 death cases in the United States in 2024. Renal cell carcinoma (RCC) is the most common subtype of renal cancer, accounting for more than 90% of all renal cancer cases. Local renal cancer can be treated by surgery, but advanced renal cancer is not sensitive to radiotherapy and chemotherapy and has a poor prognosis. About 20% to 30% of renal cancer patients have metastasis at the time of diagnosis, and the 5-year survival rate is only about 12%.

[0004] In recent years, targeted therapy has become a popular direction for the treatment of renal cancer, and several molecular targeted drugs have been launched successively, which have achieved remarkable effects in the treatment of RCC. The receptor tyrosine kinase inhibitors (TKIs) represented by sunitinib are currently the first-line treatment for advanced renal cancer.

[0005] Although sunitinib greatly improves the treatment effect of advanced renal cancer, long-term use of sunitinib will gradually induce tumor drug resistance and reduce the clinical efficacy of the drug. About 20% of patients will show congenital drug resistance when taking sunitinib for the first time, and most patients will develop secondary drug resistance after 6-11 months of sunitinib treatment, leading to progression and metastasis of renal cancer.

[0006] At present, the specific mechanism of sunitinib-resistant renal cancer is not clear, and there is also a lack of effective biological markers to predict sunitinib-resistant renal cancer, and there is also a lack of effective treatment methods to reverse or delay drug resistance. Therefore, there is an urgent need in the art to explore the molecular mechanism of sunitinib-resistant renal cancer and the key gene targets of renal cancer drug resistance, to find diagnostic markers that can effectively predict the efficacy of sunitinib according to these targets, and to develop new drugs to reverse sunitinib-resistant renal cancer, so as to improve the efficacy of sunitinib treatment for renal cancer.

[0007] KAT2A, also known as acetyltransferase GCN5 (General control non-derepressible 5, GCN5), is the first identified histone acetyltransferase, belonging to the HAT superfamily. KAT2A is expressed in many mammalian tissues and cells; it is mainly distributed in the nucleus, but also found in the cytoplasm and mitotic bodies. KAT2A is involved in a wide range of cellular processes, including chromatin regulation, autophagy, neuronal apoptosis, cell proliferation, chromosome condensation, inflammation, stem cell differentiation, hematopoiesis and oxidative stress, etc.

[0008] KAT2A plays a key role in the occurrence and pathogenesis of different cancers. KAT2A has a significant impact on the prognosis of non-small cell lung cancer, acute lymphoblastic leukemia, colon cancer, liver cancer and breast cancer. KAT2A is highly expressed in non-small cell lung cancer, which enhances the growth of non-small cell lung cancer by promoting the expression of E2F1, cyclin D1 and cyclin E1. The deletion of KAT2A reduces the expression of c-MYC, inhibits cell proliferation and increases the death of non-small cell lung cancer cells. The expression of KAT2A is significantly up-regulated in human colon adenocarcinoma tissues, and the bidirectional regulation of E2F1 and c-Myc on KAT2A plays an important role in the progression of colorectal cancer. KAT2A acetylates E2A-PBX1 and increases the stability of E2A-PBX1 protein in cells, promoting the progression of acute lymphoblastic leukemia (ALL). In human hepatocellular carcinoma, KAT2A expression is up-regulated, which synergizes with E2F1 to enhance AIB1 transcription and promote liver cancer progression. KAT2A can play a role downstream of the TGF-β / Smad signaling pathway, regulating the epithelial-mesenchymal transition (EMT) and progression of breast cancer. Our previous studies have shown that KAT2A is an independent risk factor for poor prognosis of renal cancer, and high expression of KAT2A can promote renal cancer cell proliferation, migration and distant metastasis.

[0009] In addition, KAT2A is closely related to tumor chemotherapy resistance / sensitivity. In breast cancer drug-resistant cells, KAT2A promotes the expression of AIB1 in breast cancer by reducing the level of p53, mediates tamoxifen resistance, indicating that KAT2A and its downstream effectors can be used as potential therapeutic targets to prevent or overcome tamoxifen resistance in breast cancer. Acute myeloid leukemia (AML) except acute promyelocytic leukemia (APL) is resistant to all-trans retinoic acid (ATRA). KAT2A maintains the expression of stem cell and leukemia-related genes by abnormal acetylation of histone 3 histone 9 (H3K9ac) residues, and promotes the resistance of non-APL acute myeloid leukemia to ATRA. The strategy of targeting epigenetic factors by combining KAT2A and LSD1 inhibitors may reverse the resistance of non-acute promyelocytic leukemia AML to ATRA. Studies have shown that KAT2A-ATM axis mediates the occurrence of acquired resistance of topoisomerase inhibitors in leukemia treatment. SUMMARY

[0010] In view of the deficiencies of the prior art, the purpose of the present application is to provide an application of histone acetyltransferase KAT2A as a diagnostic marker for renal cancer sunitinib resistance. By studying the clinical significance of KAT2A in renal cancer tissue and the molecular pathways regulating the proliferation of renal cancer cells, the results show that KAT2A can be used as a new target for the treatment of renal cancer sunitinib resistance, providing a potential intervention target for the treatment of renal cancer drug-resistant and metastatic patients; the application of the active ingredient for down-regulating or blocking the expression of KAT2A molecules in renal cancer in the preparation of anti-renal cancer drug-resistant drugs. At the same time, a method and kit with good sensitivity are provided for the diagnosis of renal cancer drug resistance, and a feasible basis for treatment is provided.

[0011] The technical scheme adopted by the present application is as follows: In a first aspect of the present application, an application of histone acetyltransferase KAT2A is provided, including any of the following applications: application as a diagnostic marker for renal cancer sunitinib resistance; application in the preparation of a kit for detecting renal cancer sunitinib resistance; application in the preparation of a diagnostic or therapeutic agent for renal cancer drug resistance.

[0012] Among them, KAT2A is a member of the histone acetyltransferase family.

[0013] In a second aspect of the present invention, a kit for detecting sunitinib resistance in renal cancer is provided, comprising a reagent for detecting KAT2A expression; the reagent is used to detect KAT2A expression in a biological sample, and the KAT2A expression level is detected by real-time fluorescence quantitative PCR technology; the biological sample is selected from a subject's fresh tissue or cells, whole blood, serum, plasma, platelets, other body fluids (such as urine, saliva), or formalin-fixed and paraffin-embedded (FFPE) tissue or cells; and the reagent is selected from a probe, gene chip, antibody, or PCR primer with specificity for KAT2A detection.

[0014] Using this kit to detect the expression level of KAT2A can further provide evidence for the prognosis or progression of renal cancer patients, and also provide a new intervention strategy for the treatment of renal cancer patients who are resistant to sunitinib.

[0015] Furthermore, the kit is used to detect the expression level of KAT2A in tissue specimens or biological samples by real-time fluorescence quantitative PCR technology.

[0016] Furthermore, the kit also contains a standard sample or a molecular weight marker of KAT2A.

[0017] Furthermore, the kit contains amplification primers or binding polypeptides for detecting KAT2A.

[0018] Furthermore, the amplification primers for detecting KAT2A are as follows: Upstream primer: 5'-TGACCCGAAGCACAAGACTC-3', Downstream primer: 5′-ACAATCTCCGTGAAGCCCTG-3′.

[0019] In a third aspect of the present invention, there is provided a method for preparing a drug for treating drug-resistant renal cancer using a reagent for downregulating or blocking the activity of KAT2A molecules in renal cancer.

[0020] In a fourth aspect of the present invention, an anti-renal cancer drug resistance drug is provided, wherein the active ingredient of the anti-renal cancer drug resistance drug is a component that downregulates or blocks the activity of the KAT2A molecule in renal cancer.

[0021] Among them, the reagent for downregulating or blocking the activity of the KAT2A molecule in renal cancer in the third aspect or the component for downregulating or blocking the activity of the KAT2A molecule in renal cancer in the fourth aspect is a KAT2A inhibitor, a KAT2A antagonist, a KAT2A antibody, an RNA interference molecule or an antisense oligonucleotide targeting the KAT2A coding sequence.

[0022] In one or some embodiments of the present application, the active ingredient of the anti-renal cancer drug resistance drug is an inhibitor CPTH2 of KAT2A.

[0023] In a fifth aspect of the present application, a method for screening an anti-renal cancer sunitinib drug resistance drug is provided, which comprises the step of detecting the expression amount of KAT2A.

[0024] Compared with the related art known to the present inventors, one of the technical solutions of the present application has the following beneficial effects: The present application helps to provide a new direction for renal cancer sunitinib drug resistance. The present application has great significance for the selection of treatment plan for renal cancer patients, reduction of recurrence, and improvement of survival rate of patients.

[0025] The present application discloses the application of KAT2A as a renal cancer drug resistance treatment target. The use of this target can effectively prevent and treat renal cancer sunitinib drug resistance, improve the efficacy while reducing the side effects, and has great significance for developing targeted treatment of renal cancer and even developing new individualized comprehensive treatment methods. The use of KAT2A as a diagnostic marker for renal cancer sunitinib drug resistance involved in the present application is disclosed for the first time. Since KAT2A is highly expressed in drug-resistant renal cancer, down-regulating KAT2A significantly inhibits the cell activity of drug-resistant renal cancer cells (786-O-R and ACHN-R cells) in sunitinib, and promotes sunitinib sensitization, which has outstanding substantial features. Therefore, the application of KAT2A in the prevention and treatment of renal cancer sunitinib drug resistance has made a pioneering progress. BRIEF DESCRIPTION OF DRAWINGS

[0026] The drawings accompanying the specification of the present application form a part thereof and serve to provide further understanding of the present application, the exemplary embodiments of the present application and their descriptions serve to explain the present application, and do not constitute an improper limitation on the present application.

[0027] Figure 1 The expression of KAT2A mRNA in the renal cancer tissues of sunitinib-sensitive and drug-resistant renal cancer patients.

[0028] Figure 2 ROC curve analysis for the diagnostic significance of predicting the sunitinib drug resistance of ccRCC patients by the expression level of KAT2A.

[0029] Figure 3 The change in the proliferation ability of sunitinib drug-resistant renal cancer cell lines and non-drug-resistant cells under different sunitinib concentrations.

[0030] Figure 4 It is shown that the mRNA expression level of KAT2A in two sunitinib drug-resistant renal cancer cells (786-O-R, ACHN-R) is significantly higher than that in the parent cells (786-O, ACHN).

[0031] Figure 5 It is shown that down-regulation of KAT2A using KAT2A shRNA significantly down-regulates the proliferation ability of drug-resistant renal cancer cells in sunitinib, and promotes the sensitivity of drug-resistant renal cancer cells to sunitinib.

[0032] Figure 6 It is shown that the specific inhibitor CPTH2 of KAT2A significantly inhibits the proliferation ability of drug-resistant renal cancer cells (786-O-R, ACHN-R) in sunitinib, and enhances the sensitivity of drug-resistant renal cancer cells to sunitinib.

[0033] Figure 7 It is shown that the specific inhibitor CPTH2 of KAT2A can improve the sensitivity of drug-resistant renal cancer to sunitinib in mice. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed description is exemplary in nature and is intended to provide further description of the application. 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 application belongs.

[0035] It should be noted that the terms used herein are only intended to describe specific embodiments and are not intended to limit exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, they indicate the presence of the features, steps, operations and / or combinations thereof.

[0036] The present inventors investigated the mRNA expression of KAT2A in renal cancer tissues of renal cancer patients. The results of qRT-PCR experiments showed that the expression of KAT2A in renal cancer tissues of sunitinib-resistant renal cancer patients was significantly higher than that of non-drug-resistant renal cancer patients, indicating that KAT2A might become a new biomarker. Predicting the drug resistance of renal clear cell carcinoma patients to sunitinib by KAT2A expression level has certain diagnostic significance.

[0037] By long-term administration of sunitinib with gradually increasing concentration, sunitinib-resistant cell lines (786-O-R, ACHN-R) were established. CCK-8 experiments showed that the half inhibitory concentration IC 50 significantly increased, indicating that the sunitinib-resistant renal cancer cell lines were successfully constructed, and 786-O-R and ACHN-R cells can be used as in vitro cell models for subsequent renal cancer drug resistance research.

[0038] qRT-PCR was used to compare KAT2A expression levels in 786-O and 786-OR, and ACHN and ACHN-R cells. The results showed that KAT2A mRNA expression levels were significantly higher in drug-resistant cells (786-OR or ACHN-R) than in parental cells.

[0039] The established drug-resistant renal cancer cell lines 786-OR and ACHN-R were selected for loss-of-function studies. Lentiviral-mediated shRNA was used to inhibit KAT2A expression in 786-OR and ACHN-R cells. CCK-8 assays showed that the IC of shKAT2A-resistant renal cancer cells in the sunitinib group was significantly decreased. 50 It was significantly lower than that in the control group cells, indicating that knocking down KAT2A could enhance the growth inhibitory effect of sunitinib on drug-resistant renal cancer cells and enhance the sensitivity of drug-resistant renal cancer cells to sunitinib.

[0040] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0041] The detection method for detecting KAT2A in this embodiment has the following specific steps: 1. Total RNA extraction from tissues or cells: 1) Remove approximately 50 mg of renal cancer tissue from liquid nitrogen and place it in a 2 ml enzyme-free EP tube. Add 1 ml of Trizol and homogenize thoroughly with a tissue homogenizer. Incubate the cells at room temperature for 5 minutes to lyse the cells. For total RNA extraction, wash the cells twice in the dish with PBS, add 1 ml of Trizol and lyse the cells at room temperature for 5 minutes, then transfer the cells to an enzyme-free EP tube.

[0042] 2) Add about 200 ml of chloroform, cap the tube tightly, and flip it upside down by hand to ensure full contact between the solutions in the EP tube. Then, let it stand at room temperature for 10 minutes. 3) Precool the centrifuge to 4°C, balance, and centrifuge at 12,000 rpm for 15 minutes. 4) Use a pipette to transfer the upper aqueous phase to another 2 ml enzyme-free centrifuge tube; 5) Add 500 ml of isopropanol to the centrifuge tube, mix thoroughly, and let stand at room temperature for 10 minutes; 6) Place the centrifuge tube in a 4°C centrifuge, balance, and centrifuge at 12,000 rpm for 10 minutes. 7) Discard the supernatant. A trace amount of white RNA precipitate will be seen at the bottom of the tube. Add 1 ml of pre-chilled 75% ethanol to resuspend. 8) Precool the centrifuge to 4°C, balance, and centrifuge at 8000 rpm for 5 minutes. 9) Discard the supernatant, retain the precipitate, and dry at room temperature for 5 minutes; 10) Add DEPC water 20-40 mL to dissolve the precipitate; 11) After detecting the concentration and purity of RNA by spectrophotometer, store the RNA in -80℃ refrigerator for later use.

[0043] Note: All instruments during the experiment are free of RNAase contamination.

[0044] 2. qRT-PCR experiment is used to detect the expression of KAT2A mRNA: 1) Reverse transcription of RNA into cDNA In a 10 μL reaction system, use 500 ng of total RNA as a template, and configure the corresponding reaction system according to the instructions of TaKaRa PrimeScript TMRT reagent Kit (Perfect Real Time) reverse transcription kit. All operations are strictly performed on ice. In order to ensure the accuracy of the reaction liquid preparation, the reaction liquid is prepared according to the volume of about 3 holes more than the actual amount. After the reaction system is correctly prepared, reverse transcription reaction is immediately performed. The reaction conditions are: 37℃, reaction for 15 min→ 85℃, reaction for 5 s→ 4℃, reaction for an indefinite time. The obtained reverse transcription product cDNA can be directly used for the following qRT-PCR experiment, or it can be stored in a -80℃ refrigerator for later use.

[0045] 2) qRT-PCR reaction According to the instructions of TaKaRa kit, configure the corresponding reaction system, and add the reagents listed in the following table to the pre-cooled EP tube in turn. All operations are strictly performed on ice.

[0046] Table 1 qRT-PCR amplification reaction system configuration

[0047] Amplification program: First step: pre-denaturation (95℃, reaction for 30 s, 1 cycle); Second step: PCR reaction (95℃, reaction for 5 s→ 60℃, reaction for 30 s, 40 cycles); Third step: melting curve (95℃, reaction for 15 s→ 60℃, reaction for 15 s→ 95℃, reaction for 15 s, 1 cycle).

[0048] Example 1 1. Renal cancer tissue samples

[0049] The tumor primary lesions obtained after urological surgery for kidney cancer were collected, and the specimens were immediately treated with liquid nitrogen and stored in a -80°C refrigerator, or paraffin-embedded after formalin fixation. The specimens were used for PCR, Western Blot, tissue chip production, and immunohistochemical analysis. The basic information and clinical information of the patients, including age, gender, tumor size, Fuhrman grade, and TNM stage, were statistically analyzed. The TNM stage was referred to the American Cancer Society 2010 kidney cancer staging standard.

[0050] 2. Follow-up The prognosis was followed up by telephone, outpatient service, and medical records, including recurrence, metastasis time, target drug treatment time, disease progression time, survival status and time, and imaging data.

[0051] The pathological diagnosis of the clinical cases involved in this study was clear cell renal cell carcinoma (ccRCC), and recurrence or metastasis occurred after surgery and regular treatment with sunitinib for more than 3 months. A total of 43 eligible patients were randomly divided into a screening set (n=22) and a validation set (n=21). The starting point of the study was the time when regular treatment with sunitinib was started, and the endpoints included disease progression time and death time.

[0052] The evaluation criteria for the efficacy of the drug on the tumor were based on the Response Evaluation Criteria in Solid Tumors (RECIST). Specifically, the baseline of the lesions was determined by imaging before receiving target drug treatment, and the sum of the longest diameters of all target lesions was used as the reference baseline for effective remission records. The disease efficacy criteria included: ① complete remission (CR), all target lesions disappeared; ② partial remission (PR), the sum of the maximum diameters of the target lesions decreased by ≥30% and maintained for at least 4 weeks; ③ stable disease (SD), the sum of the maximum diameters of the target lesions decreased by less than PR or increased by less than PD criteria; and ④ progressive disease (PD), the sum of the maximum diameters of the target lesions increased by ≥20% or new lesions appeared.

[0053] According to the RECIST 1.1 criteria, the patients involved in this study were divided into a sunitinib-sensitive group and a drug-resistant group. The classification criteria were as follows: the sensitive group included patients with CR, PR, or SD for at least 8 months; and the drug-resistant group included patients with PD within 8 months.

[0054] 3. Detection of KAT2A expression in kidney cancer pathological tissues of sunitinib-sensitive and drug-resistant patients qRT-PCR was used to detect the mRNA expression level of KAT2A in renal cancer tissues of patients in the sunitinib-resistant and sensitive groups. The results showed that the expression level of KAT2A in renal cancer tissues of patients with sunitinib resistance was significantly higher than that in the sensitive group ( Figure 1 , P <0.01).

[0055] 4. ROC curve analysis and validation of the diagnostic significance of KAT2A expression level in predicting sunitinib resistance in ccRCC patients The AUC of KAT2A for predicting sunitinib resistance in ccRCC patients was 0.8667 (95% confidence interval: 0.7169-1.000, P =0.0037), with a sensitivity of 80.00% and a specificity of 75.00%. Therefore, the expression level of KAT2A has a certain diagnostic significance in predicting the resistance of ccRCC patients to sunitinib. Figure 2 .

[0056] Example 2

[0057] Renal cell carcinoma cell lines 786-O and ACHN were used as constructs. Sunitinib-resistant cell lines (786-OR and ACHN-R) were established by chronically administering increasing concentrations of sunitinib. The renal cell lines were digested, resuspended into single cells, counted, and plated at 1000 cells per well in a six-well plate containing 5 mM sunitinib. The cells were shaken thoroughly to distribute the cells individually and cultured in a constant-temperature incubator. After the single cells attached and formed clusters, they were digested and expanded in culture flasks and maintained in medium containing 5 mM sunitinib for one generation. Subsequently, the cells were cultured at increasing concentrations of 10 mM, 15 mM, and 20 mM, ultimately maintaining the cells at 20 mM.

[0058] CCK-8 kit was used to detect the half inhibition rate (IC50) of sunitinib on the proliferation of renal cancer cells. 50 The experimental method is as follows: cells in good growth state are digested and resuspended, and the cell quantification is 3×10 4The cells were inoculated in 96-well plates at 100 μl per well, i.e. 3000 cells, and placed in an incubator for 24 hours. The culture medium containing sunitinib was prepared in a concentration gradient, i.e. 1 μM, 2 μM, 4 μM, 8 μM, 16 μM, 32 μM, 64 μM, 128 μM and 256 μM. After 24 hours of plating, the 96-well plates were removed, and the above culture medium containing sunitinib was replaced. Three replicates were set for each concentration, and each well contained 200 μl. The 96-well plates were placed in an incubator for 48 hours, and then removed. The detection was performed according to the method described in the CCK-8 kit. The absorbance value at 450 nm was detected by an enzyme-labeled instrument, and a drug dose-response curve was plotted. Then, the IC 50 value was calculated.

[0059] The results show that the IC 50 of sunitinib in the drug-resistant cell lines 786-O-R and ACHN-R is about 5 times higher than that in their parent cells Figure 3 , indicating that the drug-resistant renal cancer cell models are successfully constructed.

[0060] Example 3

[0061] The total RNA of the cells was extracted, and the expression level of KAT2A in 786-O and 786-O-R, ACHN and ACHN-R cells was detected by qRT-PCR. The results show that the mRNA expression level of KAT2A in the sunitinib-resistant cells 786-O-R and ACHN-R is significantly higher than that in the sunitinib-sensitive cells 786-O and ACHN Figure 4 .

[0062] Example 4

[0063] The drug-resistant renal cancer cell lines 786-O-R and ACHN-R that have been constructed are selected for loss-of-function research. The expression of KAT2A in 786-O-R and ACHN-R cells is inhibited by using shRNA regulated by a lentivirus, and then the growth inhibition effect of sunitinib on the two groups of drug-resistant renal cancer cell lines is studied. The CCK-8 experiment shows that the IC 50 of sunitinib for the shKAT2A group of drug-resistant renal cancer cells is significantly lower than that for the control group of cells Figure 5 , indicating that knocking down KAT2A can enhance the growth inhibition effect of sunitinib on drug-resistant renal cancer cells and enhance the sensitivity of drug-resistant renal cancer cells to sunitinib.

[0064] Example 5

[0065] The effect of KAT2A inhibitor CPTH2 on drug-resistant renal cancer cells was studied by cell experiment. The 786-O-R cells were divided into three groups, one group of cells was normally cultured as Ctrl group; the other two groups of cells were added with 100 mM and 200 mM of CPTH2 in the culture medium respectively as CPTH2 (100 mM) group and CPTH2 (200 mM) group. The proliferation abilities of the three groups of cells under the culture of sunitinib were compared. The research results showed that CPTH2 significantly enhanced the proliferation inhibition effect of sunitinib on 786-O-R cells, and the IC 50 values of the three groups of cells were 24.57 mM, 11.92 mM and 8.348 mM respectively. Figure 6 .

[0066] Example 6

[0067] Next, a nude mouse subcutaneous tumor experiment was carried out to study the effect of CPTH2 on drug-resistant renal cancer in vivo. The 786-O and 786-O-R cells were cultured to sufficient amount and then planted in the subcutaneous of the outer side of the middle of the armpit of nude mice to establish a CDX model (Cell-Derived Xenograft, cell line-derived xenotransplantation model) for evaluating the effect of CPTH2 on improving the sensitivity of drug-resistant renal cancer to sunitinib in vivo. Fifteen healthy, pathogen-free BALB / c nude mice (5 weeks old) were selected and randomly divided into three groups: (1) Sensitive group (Sen group): 786-O cells (5×10 5 cells) were injected subcutaneously into the outer side of the middle of the armpit of nude mice, and then PBS was injected intraperitoneally, three times a week (n=5); (2) Resistance group (Res group): 786-O-R cells (5×10 5 cells) were injected subcutaneously into the outer side of the middle of the armpit of nude mice, and then PBS was injected intraperitoneally, three times a week (n=5); (3) Resistance-CPTH2 group (Res-CPTH2 group): 786-O-R cells (5×10 5 cells) were injected subcutaneously into the outer side of the middle of the armpit of nude mice, and then CPTH2 was given, three times a week (n=5). After the tumors were formed to 100 mm 3 , the three groups of mice were given sunitinib drug 40 mg / kg / day by gavage, and the tumor volume change was measured and recorded every 5 days. The volume calculation formula was V=l / 2´a´b2 (a was the longest diameter, and b was the shortest diameter). The nude mice were sacrificed and the tumor tissues were taken out after 4 weeks of sunitinib treatment. Part of the tumor tissues were preserved in formalin, and the rest were frozen in a-80℃ refrigerator. The tumor growth curve was drawn according to the tumor growth volume of each group of mice.

[0068] The results show that the growth rate of the tumor in the Res group is obviously faster than that in the Sen group, and the growth rate of the tumor in the Res-CPTH2 group is obviously slower than that in the Res group Figure 7 , indicating that CPTH2 can improve the sensitivity of drug-resistant renal cancer to sunitinib.

[0069] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application should be equivalent replacement methods, and are all included in the protection scope of the present application.

Claims

1. Use of a histone acetyltransferase KAT2A, characterized in that, Any of the following applications: Application in diagnosis of renal cancer sunitinib drug resistance as a diagnostic marker; Application in preparation of a kit for detecting renal cancer sunitinib drug resistance; Application in preparation of a diagnostic or therapeutic drug for renal cancer drug resistance.

2. A kit for detecting sunitinib resistance of renal cancer, characterized in that, The kit comprises reagents for detecting the expression level of KAT2A.

3. The kit for detecting renal cancer sunitinib resistance according to claim 2, wherein the sunitinib is a compound represented by the following formula (I) : ###0001### (I) wherein R represents a hydrogen atom or a methyl group. The reagent is used for detecting the expression level of KAT2A in a biological sample, and the expression level of KAT2A is detected by real-time fluorescent quantitative PCR technology; the biological sample is selected from fresh tissue or cells, whole blood, serum, plasma, platelets, other body fluids of a subject, or formalin-fixed and paraffin-embedded (FFPE) tissue or cells; the reagent is selected from a probe, a gene chip, an antibody or a PCR primer specific for KAT2A.

4. The kit for detecting renal cancer sunitinib resistance according to claim 2, wherein the sunitinib is a compound represented by the following formula (I) : ###0001### (I) The kit also contains a standard sample or a molecular weight marker of KAT2A. ​ 5. The kit for detecting sunitinib resistance in renal cancer according to claim 2, wherein: The kit contains amplification primers or binding polypeptides for detecting KAT2A.

6. The kit for detecting sunitinib resistance in renal cancer according to claim 5, characterized in that: The amplification primers for detecting KAT2A are as follows: Upstream primer: 5'-TGACCCGAAGCACAAGACTC-3', Downstream primer: 5'-ACAATCTCCGTGAAGCCCTG-3'.

7. Application of a reagent for down-regulating or blocking the molecular activity of KAT2A in renal cancer in the preparation of an anti-renal cancer drug-resistant drug.

8. The use according to claim 7, characterized in that The reagent for down-regulating or blocking the molecular activity of KAT2A in renal cancer is an inhibitor of KAT2A, an antagonist of KAT2A, an antibody of KAT2A, an RNA interference molecule or an antisense oligonucleotide against the coding sequence of KAT2A.

9. A drug for resisting drug resistance of kidney cancer, characterized in that, The active ingredient of the anti-renal cancer drug-resistant drug is the component for down-regulating or blocking the molecular activity of KAT2A in renal cancer.

10. A method for screening a drug for resistance to sunitinib against renal cancer, characterized by, The method comprises the step of detecting the expression level of KAT2A.

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