Application of GSK-F1 in preparation of drugs for reducing NSUN2 protein stability, solid tumor targeted therapy and / or radiotherapy sensitization

Abstract

The invention belongs to the field of anti-solid tumor drugs, and particularly relates to application of GSK-F1 in preparation of drugs for reducing the stability of NSUN2 protein, targeted therapy of solid tumors and / or radiotherapy sensitization. The research shows that the GSK-F1 has the effect of inhibiting the stability of the NSUN2 protein, and can realize targeted therapy and radiotherapy sensitization on solid tumors on the basis of inhibiting the stability of the NSUN2 tumor protein.

Description

Technical Field

[0001] This invention belongs to the field of anti-solid tumor drugs, specifically involving the application of GSK-F1 in the preparation of drugs that reduce the stability of NSUN2 protein, target solid tumor therapy and / or radiosensitizer. Background Technology

[0002] Solid tumors are a type of tumor that grows in solid organs or tissues, forming palpable and visible solid structures. Examples include lung cancer, breast cancer, nasopharyngeal carcinoma, liver cancer, pancreatic cancer, and colorectal cancer. Radiotherapy and chemotherapy are among the main treatment methods for malignant tumors, but radiotherapy and chemotherapy resistance is a fundamental cause of treatment failure and recurrence. Tumorigenesis involves the activation of oncogenes and the inactivation of tumor suppressor genes. The abnormal expression of these oncogenes and tumor suppressor genes is a crucial molecular mechanism driving tumor development and the formation of treatment resistance, and represents important molecular targets for the development of targeted cancer drugs. Therefore, screening and identifying key target genes closely related to the occurrence and treatment resistance of malignant tumors, and developing novel treatment strategies for malignant tumors, are at the forefront and a hot research topic.

[0003] NSUN2 (NOP2 / Sun RNA methyltransferase 2) is an important m5C RNA methyltransferase belonging to the conserved RNA modifying enzyme family and has been proven to be a key factor in regulating mRNA stability and translation efficiency. This invention found that NSUN2 is highly expressed in tumors such as nasopharyngeal carcinoma, breast cancer, lung cancer, and liver cancer, and is positively correlated with clinical progression and poor prognosis in patients. Furthermore, it was demonstrated that NSUN2 can promote the proliferation, migration, and invasion of nasopharyngeal carcinoma, liver cancer, and lung cancer cells, and promote tumor growth and radioresistance formation in nasopharyngeal carcinoma, thereby exerting its tumor gene function. This suggests that NSUN2 may be an important molecular target for solid tumor treatment and radiosensitization. However, no small molecule inhibitors or antitumor drugs targeting the tumor protein NSUN2 have been reported in the literature to date. Using computer-aided molecular docking and a series of molecular and cell biology techniques, GSK-F1 was screened and identified as a small molecule compound that can bind to and inhibit the stability of NSUN2 protein. It was also confirmed that this small molecule inhibitor can inhibit the proliferation of nasopharyngeal carcinoma cells, breast cancer cells, lung cancer cells, and liver cancer cells, inhibit tumor growth in nasopharyngeal carcinoma cells, and increase the sensitivity of nasopharyngeal carcinoma cells to radiotherapy. It is expected to become a novel targeted drug for the treatment of solid tumors and radiosensitization targeting the tumor protein NSUN2. Summary of the Invention

[0004] This invention discovers a novel use and mechanism of action for the small molecule drug GSK-F1. The invention screened and confirmed that GSK-F1 can dose-dependently reduce the stability of the NSUN2 tumor protein in solid tumors such as nasopharyngeal carcinoma, breast cancer, lung cancer, and liver cancer, and inhibit tumor cell proliferation and in vivo tumor growth in an NSUN2-dependent manner. It also enhances the inhibitory effect of radiotherapy on tumor cell proliferation and in vivo tumor growth, thereby exerting an anti-tumor effect in the treatment of solid tumors and radiosensitization, without significant toxic side effects in mice. Therefore, GSK-F1 shows promise as a potential anti-tumor drug targeting the NSUN2 tumor protein in solid tumors.

[0005] The main objective of this invention includes providing the use of GSK-F1 in the preparation of drugs that reduce the stability of NSUN2 protein. The GSK-F1 is named 5-(2-amino-4-oxo-3-(2-(trifluoromethyl)phenyl)-3,4-dihydroquinazolin-6-yl)-N-(2,4-difluorophenyl)-2-methoxypyridine-3-sulfonamide, and its structural formula is as follows:

[0006] .

[0007] Research has revealed that the oxygen atoms on the methoxy and sulfonyl groups of GSK-F1 form hydrogen bonds with the Val715 and Leu717 residues on the target protein NSUN2, thereby reducing the stability of the target protein NSUN2.

[0008] Furthermore,

[0009] The applications also include the preparation of drugs that reduce the stability of NSUN2 protein by pharmaceutically acceptable chemical modifications and / or structural simplifications of GSK-F1.

[0010] Furthermore,

[0011] The drug is prepared into a pharmaceutically acceptable dosage form; the dosage form includes oral and / or injectable dosage forms; the drug further comprises pharmaceutically acceptable excipients.

[0012] A secondary objective of this invention is to provide the use of the above-mentioned GSK-F1 in the preparation of drugs for targeted therapy and / or radiosensitization of solid tumors.

[0013] The oxygen atoms on the methoxy and sulfonyl groups of GSK-F1 form hydrogen bonds with the Val 715 and Leu 717 residues on the target protein NSUN2, thereby reducing the stability of the target protein NSUN2 and achieving the effect of targeted therapy and / or radiosensitization for solid tumors.

[0014] Furthermore,

[0015] This also includes preparing drugs for targeted therapy and / or radiosensitization of solid tumors by pharmaceutically acceptable chemical modifications and / or structural simplifications of GSK-F1.

[0016] Furthermore,

[0017] The drug is prepared into a pharmaceutically acceptable dosage form; the dosage form includes oral and / or injectable dosage forms; the drug further comprises pharmaceutically acceptable excipients.

[0018] Furthermore, the solid tumors mentioned include at least one of nasopharyngeal carcinoma, breast cancer, lung cancer, and liver cancer.

[0019] The dosage form described in this invention can further be a powder for injection, an injection solution, a tablet, a pill, a capsule, a spray, a dispersion, etc. The routes of administration include, but are not limited to, administration to the tumor, intravenous, arterial, intraperitoneal, and oral administration.

[0020] Beneficial effects of the invention

[0021] This invention, GSK-F1, can target and inhibit the NSUN2 protein, exhibiting a strong tumor growth inhibitory effect in solid tumors. It can be used to prepare drugs for the prevention and / or treatment of malignant tumors. In vitro experiments demonstrate that GSK-F1 can inhibit the proliferation of nasopharyngeal carcinoma, breast cancer, lung cancer, and liver cancer cells, and promote the inhibitory effect of radiotherapy on tumor cell proliferation in nasopharyngeal carcinoma. In vivo experiments show that GSK-F1 can inhibit the in vivo growth of nasopharyngeal carcinoma cells and increase tumor sensitivity to radiotherapy, demonstrating good therapeutic potential and application prospects. The drug GSK-F1 provided by this invention, which targets and inhibits the NSUN2 protein to prevent and / or treat and / or radiosensitize solid tumors, can be further formulated into a drug dosage form that is convenient for clinical use and can achieve optimal efficacy, possessing high clinical application value. Attached Figure Description

[0022] Figure 1 Results of prediction of the expression and binding ability of the small molecule compound GSK-F1 on NSUN2 protein;

[0023] in:

[0024] Figure 1 A: Results of Western blot analysis of NSUN2 protein expression levels after treating nasopharyngeal carcinoma cells (CNE2, 5-8F) with different concentrations of GSK-F1 for the same time.

[0025] Figure 1 B: The results of Western blot analysis of NSUN2 protein expression levels were obtained by treating MCF-7 breast cancer cells with different concentrations of GSK-F1 for the same time.

[0026] Figure 1 C: The results of Western blot analysis of NSUN2 protein expression levels after treating lung cancer cells A549 with different concentrations of GSK-F1 for the same time.

[0027] Figure 1 D: The results of Western blot analysis of NSUN2 protein expression levels after treating Hep3B liver cancer cells with different concentrations of GSK-F1 for the same time.

[0028] Figure 1 E: Schematic diagram of the predicted binding ability between GSK-F1 and NSUN2 through molecular docking simulation analysis.

[0029] Figure 2 Detection of the binding affinity and stability of small molecule compound GSK-F1 with NSUN2;

[0030] in:

[0031] Figure 2 A: The effect of GSK-F1 binding to NSUN2 on the stability of NSUN2 protein in nasopharyngeal carcinoma CNE2 cells was detected by thermal stability assay. DMSO was the control group and GSK-F1 was the treatment group.

[0032] Figure 2 B: The effect of GSK-F1 binding to NSUN2 on the stability of NSUN2 protein in nasopharyngeal carcinoma 5-8F cells was detected by thermostability assay, with DMSO as the control group and GSK-F1 as the treatment group.

[0033] Figure 2 C: After co-treatment with actinomycin C (CHX) for different times (0 h, 4 h, 8 h, 12 h), the effect of GSK-F1 on the stability of NSUN2 protein in nasopharyngeal carcinoma CNE2 cells was detected by Western blot.

[0034] Figure 2 D: After co-treatment with actinomycin C (CHX) for different times (0 h, 4 h, 8 h, 12 h), the effect of GSK-F1 on the stability of NSUN2 protein in nasopharyngeal carcinoma 5-8F cells was detected by Western blot.

[0035] Figure 3 The killing and radiosensitizing effects of GSK-F1 on solid tumor cells depend on its targeted inhibition of the NSUN2 protein.

[0036] in:

[0037] Figure 3A: Results of IC50 values ​​detected by CCK8 assay after treating nasopharyngeal carcinoma cells with different concentrations of GSK-F1 for 24 h and 48 h.

[0038] Figure 3 B: Results of IC50 values ​​detected by CCK8 assay after treating breast cancer cells with different concentrations of GSK-F1 for 48 h;

[0039] Figure 3 C: Results of IC50 values ​​detected by CCK8 assay after treating lung cancer cells with different concentrations of GSK-F1 for 48 h;

[0040] Figure 3 D: Results of IC50 values ​​detected by CCK8 after treating liver cancer cells with different concentrations of GSK-F1 for 48 h;

[0041] Figure 3 E: Results of NSUN2 protein expression detection in radiotherapy-resistant cells;

[0042] Figure 3 F: The viability of nasopharyngeal carcinoma cells (CNE2, 5-8F) was detected by CCK8 assay after radiotherapy alone, radiotherapy combined with GSK-F1, or radiotherapy combined with GSK-F1 and restoration of NSUN2 expression.

[0043] Figure 3 G: Apoptosis rate of nasopharyngeal carcinoma cells (CNE2, 5-8F) after radiotherapy alone, GSK-F1 combined with radiotherapy, or GSK-F1 combined with radiotherapy + restoration of NSUN2 expression was detected by flow cytometry.

[0044] The data are presented as mean ± standard error, and three independent experiments were conducted. ; ; There was no statistically significant difference between the two values ​​(ns).

[0045] Figure 4 The inhibitory and radiosensitizing effects of GSK-F1 on tumor growth in tumor-bearing mice depend on its targeted inhibition of the NSUN2 protein.

[0046] Figure 4 A: Photos of tumor-bearing mice in the Ctrl group (control group), GSK-F1 group, Ctrl-IR group (radiotherapy induction group), and GSK-F1-IR group (GSK-F1 synergistic radiotherapy induction group);

[0047] Figure 4 B: Photographs of transplanted tumors removed from the Ctrl, GSK-F1, Ctrl-IR and GSK-F1-IR groups after the mice were euthanized;

[0048] Figure 4 C: Weight results of xenografts in the Ctrl group, GSK-F1 group, Ctrl-IR group and GSK-F1-IR group;

[0049] Figure 4 D: Mouse tumor growth curve plotted by measuring tumor size every 2 days;

[0050] Figure 4 E: Results of weighing mice in the Ctrl group, GSK-F1 group, Ctrl-IR group and GSK-F1-IR group;

[0051] The data is presented as mean ± standard error. ; ; There was no statistically significant difference between the two values ​​(ns).

[0052] Figure 5 Immunohistochemical detection of the expression of related molecules and the effect of GSK-F1 on organ toxicity in tumor-bearing mice;

[0053] in:

[0054] Figure 5 A: The expression levels of NSUN2, γ-H2AX, Ki67 and cleaved-PARP (c-PARP) in tumors of the Ctrl group, GSK-F1 group, Ctrl-IR group and GSK-F1-IR group were detected by IHC.

[0055] Figure 5 B: The heart, liver, spleen, lung, and kidney of mice in the Ctrl group, GSK-F1 group, Ctrl-IR group, and GSK-F1-IR group were removed, and HE staining was performed to observe the results of each organ and tissue condition. Detailed Implementation

[0056] The present invention will be further described below with reference to specific embodiments, but not in a way that limits the invention.

[0057] The cell lines CNE2, 5-8F, MCF-7, A549, Hep3B, and CNE2-IRR (radiotherapy-resistant cells derived from the mother cell CNE2) used in this invention were all preserved by the Cancer Institute of Central South University. Cell culture conditions were as follows: adherent growth in 1640 and DMEM liquid medium containing 10% fetal bovine serum (FBS) and 1% penicillin and streptomycin, in a constant temperature incubator at 37°C and 5% CO2 concentration.

[0058] Example 1: GSK-F1 dose-dependently targets and inhibits NSUN2 protein expression in solid tumor cells.

[0059] 1.1 Experimental Design:

[0060] Nasopharyngeal carcinoma cells CNE2 and 5-8F, breast cancer cells MCF-7, lung cancer cells A549, and liver cancer cells Hep3B were treated with different concentrations of GSK-F1 (0 µM, 0.5 µM, 1 µM, and 2 µM), respectively. Cells were collected after 12 h and protein extraction was performed immediately. The protein expression level of NSUN2 was detected by Western blotting. Furthermore, the binding affinity and binding site of GSK-F1 to NSUN2 were predicted using molecular docking.

[0061] 1.2 Experimental Results:

[0062] Western blot analysis revealed that in solid tumor cells such as nasopharyngeal carcinoma, breast cancer, lung cancer, and liver cancer, the protein expression level of NSUN2 gradually decreased with increasing GSK-F1 treatment concentration. Figure 1 The results (AD) indicate that GSK-F1 can inhibit the protein expression level of NSUN2 in a dose-dependent manner. Furthermore, molecular docking simulations show that the oxygen atoms on the methoxy and sulfonyl groups of GSK-F1 form hydrogen bonds with the Val 715 and Leu 717 residues on the target protein NSUN2, with a binding energy of -7.73 kcal / mol. Figure 1 E), thereby reducing the stability of the target protein.

[0063] Example 2: GSK-F1 targets and reduces the stability of NSUN2 protein

[0064] 2.1 Experimental Procedure:

[0065] The binding affinity between the small molecule GSK-F1 and the NSUN2 protein was verified using a GETSA (Germ-Transfer Assay) assay. Simultaneously, the effect of GSK-F1 on the stability of the NSUN2 protein was investigated using stability assays.

[0066] 2.2 Experimental Results:

[0067] In nasopharyngeal carcinoma cells CNE2 and 5-8F, the small molecule inhibitor GSK-F1 was confirmed to have good binding ability to NSUN2 protein in vitro by the cell thermal displacement assay (GETSA). Figure 2 AB). After treatment with actinomycete ketone (CHX) for 0 h, 4 h, 8 h, and 12 h, Western blot analysis of NSUN2 protein stability revealed that GSK-F1 promoted the degradation of NSUN2 protein. Figure 2 CD).

[0068] Example 3: GSK-F1 promotes the killing of solid tumor cells and radiosensitization by targeting and inhibiting NSUN2.

[0069] 3.1 Experimental Design:

[0070] The IC50 value of GSK-F1 against solid tumor cells was determined. Different types of solid tumor cells (CNE2, 5-8F, MCF-7, A549, Hep3B) were seeded at 2000 cells / well in 96-well plates. The control groups were 1640 medium and DMEM medium (containing serum) but cell-free. Different concentrations of GSK-F1 were set to treat CNE2, 5-8F, MCF-7, A549, and Hep3B tumor cells, respectively. Concentration gradients were set at 0 µM, 4 µM, 8 µM, 16 µM, 64 µM, and 128 µM. Each concentration gradient was set in triplicate. The control group was the DMSO treatment group (Ctrl group). After 24 h and 48 h of treatment, 10% CCK8 solution was added to each well, and the cells were incubated at 37°C for 2 h. The absorbance was measured using a microplate reader (wavelength 450 nm). The IC50 values ​​of GSK-F1 against different tumor cell lines were calculated using GraphPad Prism software at 24h and / or 48h.

[0071] CNE2-IRR cells (radiotherapy-resistant cell line) and their parent CNE2 cells were collected, and total protein was extracted. The differential expression of NSUN2 in CNE2-IRR cells and their parent cells was detected by Western blot.

[0072] The effect of GSK-F1 on the radiosensitivity of nasopharyngeal carcinoma cells was investigated. Well-grown nasopharyngeal carcinoma cells (CNE2 and 5-8F) were seeded in 12-well plates. When the cell density reached 60-80%, NSUN2 transfection was performed using Polyplus. 24 hours after transfection, cell counts were performed, and cells were seeded at 1000 cells / well in 96-well plates. The control group consisted of culture medium (containing serum) but no cells. CNE2 and 5-8F cells were treated with the same drug concentration, with five replicates for each concentration gradient. The control group was treated with DMSO. After radiotherapy induction, five time points were set: 0 days, 1 day, 2 days, 3 days, and 4 days. Then, 10% CCK8 solution was added to each well, and the cells were incubated at 37°C for 2 hours. The absorbance was measured using a microplate reader (450 nm). The survival rate of tumor cells after radiotherapy or combined drug treatment is calculated using the following formula: Cell survival rate = (absorbance value of drug-treated group - absorbance value of blank group) / (absorbance value of control group - absorbance value of blank group).

[0073] The effect of GSK-F1 on radiotherapy-induced apoptosis was investigated. Well-grown nasopharyngeal carcinoma cells (CNE2, 5-8F) were seeded in 6-well plates. When the cell density reached 60-80%, NSUN2 transfection was performed using Polyplus. After 24 h of transfection, GSK-F1 was added, followed by 24 h of radiotherapy induction. Cells were then digested, and Annexin V and PI were added for flow cytometry apoptosis detection.

[0074] Ctrl: DMSO processing group

[0075] Ctrl-IR: DMSO treatment group + radiotherapy group

[0076] GSK-F1-IR: GSK-F1 treatment + radiotherapy group

[0077] GSK-F1+NSUN2-IR: GSK-F1 treatment + radiotherapy + NSUN2 recovery group.

[0078] 3.2 Experimental Results:

[0079] The CCK8 assay results showed that GSK-F1 exhibited good anti-tumor activity in solid tumor cells such as nasopharyngeal carcinoma, breast cancer, lung cancer, and liver cancer, with IC50 values ​​of CNE2 (IC50-24 h: 28.79 µM; IC50-48 h: 19.86 µM), 5-8F (IC50-24 h: 26.08 µM; IC50-48 h: 11.01 µM), MCF-7 (IC50-48 h: 4.656 µM), A549 (IC50-48 h: 5.312 µM), and Hep3B (IC50-48 h: 11.2 µM). Figure 3 AD). This indicates that GSK-F1 can significantly inhibit tumor cell growth in vitro, demonstrating a good anti-tumor effect. In radiotherapy-resistant nasopharyngeal carcinoma cells (CNE2-IRR), NSUN2 expression was higher ( Figure 3 E). The CCK8 assay results showed that GSK-F1 promoted the inhibitory effect of radiotherapy on the proliferation of nasopharyngeal carcinoma cells, while reversing NSUN2 expression reversed the synergistic inhibitory effect of GSK-F1 on radiotherapy-induced nasopharyngeal carcinoma cells. Figure 3 F). Furthermore, flow cytometry-mediated apoptosis assays showed that GSK-F1 significantly promoted radiotherapy-induced apoptosis in CNE2 and 5-8F nasopharyngeal carcinoma cells, while reversing NSUN2 reversed the synergistic promoting effect of GSK-F1 on radiotherapy-induced apoptosis in nasopharyngeal carcinoma cells. Figure 3 (G), indicating that GSK-F1 promotes radiosensitization of tumors by targeting and inhibiting NSUN2, thereby promoting the inhibition of radiotherapy-induced tumor cell proliferation and apoptosis.

[0080] Example 4: GSK-F1 exerts anti-tumor and radiosensitizing effects in tumor-bearing mice by targeting and inhibiting NSUN2.

[0081] 4.1 Experimental Procedure:

[0082] Twenty-eight 4-week-old female BALB / c nude mice, weighing 16 ± 2 g, were purchased from Hunan Slack Jingda Experimental Animal Co., Ltd. All mice passed quality inspection. Animal husbandry and related procedures were performed at the Department of Experimental Animals, Central South University, under specific pathogen-free (SPF) conditions.

[0083] (1) Prepare nasopharyngeal carcinoma cells CNE2 with good growth status. After collecting the cells, wash them twice with pre-cooled physiological saline.

[0084] (2) Prepare 3×10 for each nude mouse 6 150 μL of cell suspension was injected subcutaneously into the upper right forearm axilla of nude mice. A total of four groups were set up: control group Ctrl, GSK-F1 group, Ctrl-IR group and GSK-F1-IR group, with 7 nude mice in each group.

[0085] (3) Starting from the 8th day after injection, measure the length (L) and width (W) of the subcutaneous tumor in nude mice with calipers every 2 days, record the results and calculate the tumor volume using the following formula: Volume = L × W 2 / 2.

[0086] (4) When the tumor volume in mice reaches 50 mm 3 After lateral displacement, control group mice were injected with DMSO, Ctrl-IR group mice received DMSO injection plus radiotherapy, GSK-F1 group mice received intratumoral injection of 5 mg / kg GSK-F1 per tumor per cycle, and GSK-F1-IR group mice received intratumoral injection of 5 mg / kg GSK-F1 per tumor per cycle plus radiotherapy. Injections were given every 2 days for a total of 5 cycles.

[0087] (5) When the tumor grows to a certain size, the animal is euthanized by cervical dislocation, the tumor is removed, photographed and the tumor volume and weight are recorded.

[0088] 4.2 Experimental Results:

[0089] The results of the in vivo nude mouse xenograft model showed that, compared with the control group, the tumor growth of mice in the GSK-F1 treatment group was significantly inhibited and the tumor weight was significantly reduced. Figure 4 B shows that the tumors in the GSK-F1 group were smaller than those in the Ctrl group, and the tumors in the GSK-F1-IR group were the smallest. Figure 4 C shows that the tumors in the GSK-F1 group were lighter than those in the Ctrl group, and the tumors in the GSK-F1-IR group were the lightest. Figure 4D found that GSK-F1 significantly inhibited tumor growth rate, with the GSK-F1-IR group showing the most significant inhibition; and GSK-F1 had no effect on mouse body weight. Figure 4 E). Therefore, this indicates that GSK-F1 can significantly inhibit tumor growth in vivo, thus demonstrating an in vivo anti-tumor effect.

[0090] Example 5: Immunohistochemical detection of the expression of related molecules and the effect of GSK-F1 on organ toxicity in nasopharyngeal carcinoma-bearing mice.

[0091] 5.1 Experimental Procedure:

[0092] After dehydration, fixation, paraffin embedding, and sectioning of some tumors from each group in Example 4, the expression of NSUN2, DNA damage marker γ-H2AX, proliferation marker Ki67, and apoptosis marker cleaved-PARP in the tumors of the Ctrl group, GSK-F1 group, Ctrl-IR group, and GSK-F1-IR group was detected.

[0093] Three mice were randomly selected from each of the Ctrl group, GSK-F1 group, Ctrl-IR group, and GSK-F1-IR group. The heart, liver, spleen, lung, and kidney were dissected, dehydrated, fixed, embedded in paraffin, sectioned, and then stained with hematoxylin and eosin (HE) to observe the state of each organ and tissue.

[0094] 5.2 Experimental Results:

[0095] The expression of NSUN2, the DNA damage marker γ-H2AX, the cell proliferation-related molecule Ki67, and the apoptosis-related molecule cleaved-PARP (c-PARP) in the tumor tissues of nude mice was detected by immunohistochemistry (IHC). The results showed that compared with the control group, NSUN2 expression was significantly decreased in the GSK-F1 group and even lower in the GSK-F1-IR group. Radiotherapy promoted γ-H2AX expression, which was highest in the GSK-F1-IR group. Ki67 expression decreased in the GSK-F1 group and even lower in the GSK-F1-IR group. Cleaved-PARP expression increased in the GSK-F1 group and even higher in the GSK-F1-IR group. Figure 5 A) indicates that after GSK-F1 treatment, NSUN2 protein was inhibited in nude mouse xenografts, cell proliferation was significantly suppressed, and apoptosis was initiated. GSK-F1 treatment combined with radiotherapy significantly inhibited tumor growth. HE staining results showed no significant damage to any organs or tissues in the GSK-F1 group, indicating that GSK-F1 has a certain degree of in vivo biocompatibility. Figure 5 B). The above results indicate that GSK-F1 can significantly inhibit the growth of nasopharyngeal carcinoma cells without significant organ toxicity.

[0096] This invention demonstrates that GSK-F1 can dose-dependently target and inhibit the expression and stability of NSUN2 protein in solid tumors. It can inhibit the proliferation of solid tumor cells and in vivo tumor growth in an NSUN2-dependent manner, and increase the sensitivity of nasopharyngeal carcinoma cells to radiotherapy, thereby exerting an anti-tumor effect in solid tumors. Furthermore, it exhibits no significant toxic side effects in mice. Therefore, GSK-F1 shows promise as a potential anti-tumor drug targeting the NSUN2 protein.

Claims

1. The application of GSK-F1 in the preparation of drugs that reduce the stability of NSUN2 protein, characterized in that, The GSK-F1 is named 5-(2-amino-4-oxo-3-(2-(trifluoromethyl)phenyl)-3,4-dihydroquinazolin-6-yl)-N-(2,4-difluorophenyl)-2-methoxypyridine-3-sulfonamide, and its structural formula is as follows: 。 2. The application according to claim 1, characterized in that, The oxygen atoms on the methoxy and sulfonyl groups of GSK-F1 form hydrogen bonds with the Val 715 and Leu 717 residues on the target protein NSUN2, thereby reducing the stability of the target protein NSUN2.

3. The application according to claim 1, characterized in that, This also includes preparing drugs that reduce the stability of the NSUN2 protein by pharmaceutically acceptable chemical modifications and / or structural simplifications of GSK-F1.

4. The application according to claim 1, characterized in that, The drug is prepared into a pharmaceutically acceptable dosage form; the dosage form includes oral and / or injectable dosage forms; the drug further comprises pharmaceutically acceptable excipients.

5. The application of GSK-F1 in the preparation of sensitizing drugs for targeted therapy and / or radiotherapy of solid tumors, characterized in that, The GSK-F1 is named 5-(2-amino-4-oxo-3-(2-(trifluoromethyl)phenyl)-3,4-dihydroquinazolin-6-yl)-N-(2,4-difluorophenyl)-2-methoxypyridine-3-sulfonamide, and its structural formula is as follows: 。 6. The application according to claim 5, characterized in that, The oxygen atoms on the methoxy and sulfonyl groups of GSK-F1 form hydrogen bonds with the Val 715 and Leu 717 residues on the target protein NSUN2, thereby reducing the stability of the target protein NSUN2 and achieving the effect of targeted therapy and / or radiosensitization for solid tumors.

7. The application according to claim 5, characterized in that, This also includes preparing targeted therapy and / or radiosensitizing agents for solid tumors by pharmaceutically acceptable chemical modifications and / or structural simplifications of GSK-F1.

8. The application according to claim 5, characterized in that, The drug is prepared into a pharmaceutically acceptable dosage form; the dosage form includes oral and / or injectable dosage forms; the drug further comprises pharmaceutically acceptable excipients.

9. The application according to claim 5, characterized in that, The solid tumors mentioned include at least one of nasopharyngeal carcinoma, breast cancer, lung cancer, and liver cancer.

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