Application of MEK inhibitor combined with p53 activator in preparation of pancreatic cancer treatment drugs and construction method of drug screening platform

Abstract

The invention relates to the technical field of medicine screening, and particularly discloses application of an MEK inhibitor combined with a p53 activator in preparation of a medicine for treating pancreatic cancer and a construction method of a medicine screening platform. The MEK inhibitor trametinib is combined with the p53 activator COTI-2 to treat pancreatic cancer, it is found that trametinib and COTI-2 have a synergistic interaction effect, and the treatment effect of the combination of trametinib and COTI-2 is remarkably better than that of a single drug.

Description

Technical Field

[0001] The present invention relates to the technical field of drug screening, and in particular to the use of a MEK inhibitor combined with a p53 activator in the preparation of drugs for treating pancreatic cancer and a method for constructing a drug screening platform. Background Art

[0002] Pancreatic cancer is known as the "king of cancers" mainly because of its rapid progression, difficulty in early detection and inadequate treatment. In approximately 90% of pancreatic cancer cases, KRAS oncogenic mutations are key drivers of disease development and maintenance, leading to persistent KRAS activation. Abnormally activated KRAS genes participate in multiple downstream pathways and cellular processes. However, due to the relatively smooth surface of the KRAS protein and the lack of obvious small molecule drug binding pockets, it is difficult to develop KRAS inhibitors. Currently, in addition to targeting KRAS, there are G12C Except for small molecule inhibitors, no effective inhibitors against mutant KRAS have been developed. G12C KRAS is present in only 1.5% of human pancreatic cancers. Due to the lack of effective drugs that directly target mutant KRAS in pancreatic cancer, alternative approaches often focus on developing drugs that target related effector pathways, such as MEK inhibitors, PI3K inhibitors, mTOR inhibitors, and AKT inhibitors. However, single-agent therapies currently have poor efficacy in pancreatic cancer treatment. Therefore, there is a need to explore a combination therapy approach for pancreatic cancer treatment. Summary of the Invention

[0003] To develop a combination therapy for pancreatic cancer, the present invention provides the use of a MEK inhibitor combined with a p53 activator in the preparation of a pancreatic cancer treatment drug and a method for constructing a drug screening platform. This study combined the MEK inhibitor trametinib with the p53 activator COTI-2 to treat pancreatic cancer. Trametinib and COTI-2 demonstrated a synergistic effect, with the combined therapeutic effect significantly superior to that of either drug alone.

[0004] The present invention provides the use of a MEK inhibitor combined with a p53 activator in the preparation of a drug for treating pancreatic cancer.

[0005] The MEK inhibitor and p53 activator in the present invention have a synergistic effect in treating pancreatic cancer. The inhibitory effect of the MEK inhibitor combined with the p53 activator on tumors is significantly better than that of using the MEK inhibitor or the p53 activator alone.

[0006] Furthermore, the MEK inhibitor is trametinib, and the p53 activator is COTI-2; The structural formula of COTI-2 is: .

[0007] Furthermore, trametinib synergizes with COTI-2 to inhibit the proliferation of tumor cells and reduce tumor volume.

[0008] Furthermore, the pancreatic cancer is KRAS and TP53 double-mutant pancreatic cancer.

[0009] The present invention also provides a method for constructing a PDO and PDX / PDOX dual-model drug screening platform, comprising the following steps: Construction of a PDO in vitro model: Obtain pancreatic cancer tumor tissue samples, digest the pancreatic cancer tumor tissue samples to obtain single pancreatic cancer tumor cells, and use 3D culture methods to culture them to obtain organoids, namely the PDO in vitro model; In vivo model construction: Transplanting ex vivo pancreatic cancer tumor tissue samples into mice to construct an in vivo model; The PDO in vitro model and in vivo model together constitute an in vivo and in vitro dual-model pancreatic cancer drug screening platform; The adenocarcinoma drug comprises a MEK inhibitor combined with a p53 activator.

[0010] Furthermore, the in vivo model construction process is as follows: the ex vivo pancreatic cancer tumor tissue sample is subcutaneously transplanted into the mouse to construct an in vivo pancreatic cancer PDX model; or, the organoid is resuspended and subcutaneously injected into the mouse to construct an in vivo PDOX model.

[0011] The present invention also provides a method for screening drugs for treating pancreatic cancer, comprising the following steps: Constructing a drug screening platform according to the aforementioned construction method; First, the drug to be tested is applied to the PDO in vitro model and the efficacy is tested to screen for synergistic drug combinations. The synergistic drug combinations screened out are applied to in vivo models and subjected to efficacy testing to screen for drug combinations that have inhibitory effects on tumor growth.

[0012] Furthermore, the drug to be tested is any one of a MEK inhibitor and a p53 activator or a combination of both.

[0013] Further, the MEK inhibitor is trametinib or selumetinib; The p53 activator is COTI-2 or APR246.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This study used the MEK inhibitor trametinib in combination with the p53 activator COTI-2 to treat pancreatic cancer. Trametinib and COTI-2 demonstrated a synergistic effect, with the combined therapeutic effect significantly superior to that of either agent alone. This study demonstrated a synergistic effect of the MEK inhibitor trametinib and the p53 activator COTI-2 in both PDO and PDX / PDOX models of pancreatic cancer harboring KRAS and TP53 mutations, providing a novel approach for the treatment of pancreatic cancer.

[0015] 2. The PDO constructed by this invention retains the genetic properties of the original tissue; the constructed PDX / PDOX model not only retains the structure and function of the original tissue but also simulates the in vivo drug metabolism environment, which can reduce treatment failure caused by pancreatic cancer heterogeneity. This invention uses high-throughput sequencing of patient tissue samples to identify drug targets. Since there are many target drugs for the same target, the dual PDO and PDX / PDOX models are then used to verify the efficacy of target drugs and screen for the optimal drug combination, facilitating the screening of combined drugs for cancer treatment.

[0016] 3. By constructing patient-derived organoid (PDO) models and patient-derived xenograft tumor (PDX / PDOX) models, the genetic characteristics and heterogeneity of the tumor are retained, and the genomic and phenotypic complexity of the patient's tumor can be accurately reproduced. It is the best in vitro and in vivo model for personalized drug screening. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 Schematic diagram of the construction process of organoids of the present invention.

[0019] Figure 2 The growth morphology, histological morphology and immunophenotypic characteristics of the pancreatic cancer organoid constructed in Example 1 of the present invention; In the figure, A shows the growth morphological characteristics of pancreatic cancer organoids; B shows the growth morphological characteristics of established pancreatic cancer organoids after multiple passages; C shows the histological morphology and immunophenotypic characteristics of established pancreatic cancer organoids.

[0020] Figure 3 This is the mutation gene spectrum of 8 pancreatic cancer tissues and their corresponding organoids and 1 pancreatic cancer liver metastasis organoid.

[0021] Figure 4 Dose-effect curves and CI value analysis of tumor organoids to different drugs; In the figure, A is the dose-effect curve of PDO099 to different drugs (drug action for 96 h); B is the dose-effect curve of PDO433 to different drugs (drug action for 96 h); C is the dose-effect curve of PDO099 on trametinib and COTI-2 alone and in combination (drug action for 96 hours); D is the CI value of trametinib and COTI-2 in Figure C analyzed by CompuSyn software; E is the dose-effect curve of PDO433 on trametinib and COTI-2 alone and in combination (drug action for 96 h); F is the CI value of trametinib and COTI-2 analyzed by CompuSyn software in Figure E.

[0022] Figure 5 Construct flow charts and drug susceptibility testing results for PDX and PDOX models; In the figure, A is the flow chart for constructing PDX and PDOX models; B is the tumor volume-time curve of tumor-bearing NCG mice carrying PMC099 samples after administration; C is the weight-time curve of tumor-bearing NCG mice carrying PMC099 samples after administration; D is the tumor volume-time curve of tumor-bearing NCG mice carrying PMC433 samples after administration; E is the weight-time curve of tumor-bearing NCG mice carrying PMC433 samples after administration. DETAILED DESCRIPTION

[0023] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. The experimental methods described in the embodiments of the present invention are conventional methods unless otherwise specified, and the materials, reagents, etc. used in the following embodiments can be obtained from commercial sources unless otherwise specified.

[0024] The present invention provides the use of a MEK inhibitor combined with a p53 activator in the preparation of a drug for treating pancreatic cancer and a method for constructing a drug screening platform.

[0025] Example 1: A method for constructing a tumor organoid (PDO) and PDX / PDOX dual-model drug screening platform.

[0026] In this example, pancreatic cancer organoids were constructed using samples from pancreatic cancer patients. Two pancreatic cancer patients were selected: one with a pancreatic in situ tumor and one with a pancreatic tumor-liver metastasis.

[0027] 1. Construction of organoid (PDO) model The construction process of pancreatic cancer organoid (PDO) model is as follows Figure 1 As shown, tumor tissue samples from patients with pancreatic in situ tumors or liver biopsy samples from patients with pancreatic tumor-liver metastases are used as experimental samples. The experimental samples are then digested to obtain single cells, which are then cultured in 3D to create organoids. After the organoids are passaged and expanded, a pancreatic cancer organoid model is obtained, which can be used for drug sensitivity testing. The specific steps are as follows:

[0028] 1. Sample Acquisition: For a patient diagnosed with stage II pancreatic ductal adenocarcinoma (PMC099) and a patient diagnosed with pancreatic tumor-liver metastasis (PMC433), with informed consent, a tumor tissue sample from the patient with pancreatic ductal adenocarcinoma was surgically removed and designated as sample PMC099. A liver biopsy sample from the patient with pancreatic tumor-liver metastasis was obtained by puncture and designated as sample PMC433.

[0029] 2. Digest the sample to obtain single cells: (1) Digestion of PMC099 samples to obtain single cells: PMC099 samples were washed three times with PBS containing 2% penicillin and then minced; digested with 5 mL of basal culture medium containing 5 mg / mL collagenase II (Solebo C8150) in a 37°C constant temperature incubator for 90 minutes; after digestion, undigested tissue fragments were filtered out with a 70 μm cell mesh and the cell suspension was collected; 15 mL of basal culture medium was added to terminate the digestion, centrifuged at 4°C, 1500 rpm for 5 minutes, and the supernatant was discarded to collect the cells. Then, 5 mL of red blood cell lysis buffer (Solebo R1010) was added to the cells, pipetted to mix the suspension evenly, and allowed to stand for 10 minutes. Centrifuged at 4°C, 1500 rpm for 5 minutes, and the supernatant was discarded. 10 mL of PBS was added to resuspend the cells, and the supernatant was discarded after centrifugation at 4°C, 1500 rpm for 5 minutes. 5 mL of basal culture medium was added to resuspend the cells, and the supernatant was discarded after centrifugation at 4°C, 1500 rpm for 5 minutes to obtain the PMC099 cell sample.

[0030] Basal culture medium: 48.5 mL Advance DMEM / F12 + 500 μL 100x Glutamax + 500 μL 1M HEPES + 500 μL penicillin-streptomycin double antibody.

[0031] (2) Digestion of PMC433 samples to obtain single cells: The PMC433 samples were washed three times with PBS containing 2% penicillin and streptomycin; the samples were digested with 5 mL of basal culture medium containing 5 mg / mL collagenase II (Solabo C8150) in a 37°C constant temperature incubator for 60 min; after digestion, the undigested tissue was filtered out with a 70 μm cell sieve and the cell suspension was collected; 15 mL of basal culture medium was added to terminate the digestion, and the cells were collected by centrifugation at 4°C and 1500 rpm for 5 min, after which the supernatant was discarded to obtain the PMC433 cell sample.

[0032] 3. 3D cultured organoid models Use 100 μL of basal culture medium to resuspend the PMC099 cell sample and PMC433 cell sample respectively, then add 300 μL of matrigel (Corning 354230, matrigel). After mixing, take 75 μL of cell suspension from each well and inoculate it into a preheated 24-well plate. Place it in a 37°C cell culture incubator for more than 30 minutes. After the matrigel is completely solidified, add 500 μL of complete culture medium to each well; replace the culture medium every 3 days for organoid culture. After 10 days of culture, P0 generation organoids PDO099 and P0 generation organoids PDO433 were obtained, namely, the organoid PDO099 model and the organoid PDO433 model were obtained.

[0033] The complete culture medium formula is: Advanced DMEM / F12 (Gibco 12634010), HEPES 10mM (Biosharp BL1061A), Glutamax 1x (Gibco 35050061), Penicillin-Streptomycin 1x (HycloneSV30010), Primocin 1x (Invivogen ant-pm-1), N2 1x ( Gibco 17502048), B27 1x (Gibco 12587010), A83-01 500nM (Abmole M5037), hEGF 50ng / ml (PeproTech AF 100-15-1000), Noggin 100ng / ml (Sino Biological 10267-HNAH), hFGF10 100ng / ml (Sino Biological 10573-HNAE), R-spondin1 1μg / ml (Sino Biological 11083-HNAS), hGastrin I 10nM (Sigma-Aldrich 05-23-2301), N-acetylcysteine ​​1.25mM (Sigma-Aldrich A9165), nicotinamide 10mM (Sigma-Aldrich N0636), PGE2 1μM (Sigma-Aldrich 900117P), Forskolin 1μM (R&D1099), Y27632 10μM (Abmole Bioscience M1817).

[0034] The present invention takes photos and records the growth of organoids under a bright field microscope on the 1st, 5th and 10th day of organoid culture. Figure 2 As shown in Figure A, the pancreatic cancer organoids constructed in the present invention present a mixed morphology of cystic structure and dense structure, with different filling cavity degrees.

[0035] 4. Passaging and expanding organoid models When the P0 organoids PDO099 and PDO433 were cultured to a density of approximately 80%, they were passaged and expanded. 500 μL of Triple Digestion Solution (Thermo Fisher 12605010) was added to each well, and the solidified Matrigel was resuspended by pipetting. The cells were incubated in a 37°C cell culture incubator for digestion, and pipetting was performed every 5 minutes. The organoids (PDO099 and PDO433) were observed under a microscope until they were digested into single cells. After that, 1 mL of basal medium was added to terminate the digestion. The cell suspension was collected and centrifuged at 1500 rpm for 5 minutes at 4°C. The supernatant was discarded and the cell suspension was resuspended in 75 μL of basal medium. 225 μL of Matrigel was added and mixed. The cells were then plated in a 24-well plate at a volume of 75 μL per well and incubated at 37°C for more than 30 minutes. After the Matrigel was completely solidified, 500 μL of complete medium was added to each well and cultured for another 1 minute. This was the P1 generation. The P1 generation was expanded to 80% density and then digested and expanded once to become the P2 generation, and so on. The growth of the organoids was recorded under a bright field microscope.

[0036] The results are as follows Figure 2 As shown in Figure 2B, the long-term expansion of the organoids of the present invention has little effect on the morphology and growth rate of the organoids.

[0037] In order to characterize whether the pancreatic cancer organoids (organoid PDO099 and organoid PDO433) constructed in this example retain the characteristics of their original tumors, HE staining and immunohistochemical staining were performed.

[0038] The results are as follows Figure 2 As shown in Figure C, HE staining results show that the cultured organoid tissue morphology has a ductal cavity structure. Immunohistochemical staining for the ductal cell marker SOX9, the tumor proliferation indicator Ki67, and the pancreatic cancer tumor markers CK7 and CK20 showed that the organoids and their corresponding tissues were consistent. This shows that the morphology and histological characteristics of the pancreatic cancer organoids obtained by the present invention are highly consistent with the tissue from which they were derived, confirming that this example successfully constructed pancreatic cancer organoids.

[0039] 2. Comparative Analysis of Next-Generation Sequencing of Pancreatic Cancer Tissue Samples and Pancreatic Cancer Organoids Following the protocol used to construct organoid PDO099, we constructed corresponding organoids from surgically resected samples from seven additional patients with pancreatic ductal carcinoma. These patients were designated PMC028, PMC112, PMC128, PMC133, PMC140, PMC151, and PMC155. Genomic analysis of the tumor tissue samples and corresponding organoids from these seven patients was performed using next-generation sequencing. Sequencing and analysis were performed by Segregant Genetics.

[0040] The results are as follows Figure 3As shown, genetic mutations are heterogeneous, but the in vitro organoids of the present invention retain the vast majority of genetic mutations from the matched tissue samples, indicating that the pancreatic cancer organoids constructed by the present invention retain the genetic characteristics of the original tissue. Furthermore, statistical analysis revealed that KRAS and TP53 mutation rates were high in these samples.

[0041] 3. Drug Sensitivity Testing of Pancreatic Cancer Organoid (PDO) Model Next-generation sequencing results show that KRAS and TP53 gene mutations are highly prevalent in pancreatic cancer. Due to the large number of drugs targeting the same target, and to address the clinical limitations of targeted drug selection, this study used pancreatic cancer organoids to test their sensitivity to inhibitors of the classic KRAS downstream pathway and p53 activators, including MEK inhibitors: trametinib and selumetinib; PI3K inhibitors: apellisib and buparinibic; mTOR inhibitors: temsirolimus and everolimus; AKT inhibitor: MK2206; and mutant p53 activators: COTI-2 and APR246.

[0042] The present invention performs drug sensitivity testing on pancreatic carcinoma in situ organoids PDO099 and pancreatic tumor-liver metastasis organoids PDO433. The cultured organoids are digested and plated in 96-well plates. After 24 hours, different concentrations of the above-mentioned inhibitors or activators are added. The inhibitors and activators are all purchased from Selleck, and the final concentrations are 0.00001 μM, 0.0001 μM, 0.001 μM, 0.01 μM, 0.1 μM, 1 μM, 10 μM and 20 μM. After 96 hours of action, cell activity is detected using CTG.

[0043] The results are as follows Figure 4 A and Figure 4 As shown in Figure B, the present invention found that these drugs have inhibitory effects on both PDO099 and PDO433, indicating that the pancreatic cancer organoids constructed by the present invention can be used to predict patients' responses to targeted drugs based on mutant genes; among them, MEK inhibitors and p53 activators have better efficacy, and the proportion of KRAS gene mutations and TP53 gene mutations occurring simultaneously in the samples sequenced by the present invention is relatively high, about 77%; therefore, the present invention selected the most effective MEK inhibitor trametinib and the p53 activator COTI-2 for combination therapy, and found that the inhibitory effect of trametinib and COTI-2 combined administration was significantly higher than that of single drugs ( Figure 4 C. Figure 4 CompuSyn software calculated the CI values ​​of trametinib and COTI-2 in PDO099 and PDO433 (CI values ​​less than 1 indicate that the two drugs have a synergistic effect). It was found that the two drugs have a synergistic effect ( Figure 4 D and Figure 4F), indicating that MEK inhibitors combined with mutant p53 activators are a new treatment strategy for KRAS and TP53 double-mutant pancreatic cancer.

[0044] IV. Construction of PDX / PDOX Models and Drug Efficacy Testing After drug screening with PDO, in order to further verify the efficacy of MEK inhibitors combined with mutant p53 activators at the in vivo level (PDO / PDOX model), the present invention obtained a tumor tissue sample from a patient PMC099, washed it three times with physiological saline, cut it into small pieces, and subcutaneously transplanted it into 8-week-old NCG female mice to construct its PDX model (PDX099). For patient PMC433, since it was a puncture sample with limited material, the present invention resuspended the organoid PDO433 in a culture medium containing 50% Matrigel and subcutaneously injected it into 8-week-old NCG female mice to construct its PDOX model (PDOX433) ( Figure 5 The tumor size was measured twice a week and the tumor volume was calculated as follows: V (mm 3 ) = (length × width^2) / 2. When the tumor grows to 700mm 3 The mice were killed and disinfected with alcohol. The tumors were washed and cut into small pieces and inoculated into a new batch of NCG female mice as P1 generation. When the tumors of P1 generation mice grew to 700mm 3 , similarly, the mice were killed, disinfected with alcohol, the tumors were taken out, cleaned, cut into small pieces, and then inoculated into a new batch of NCG female mice as the P2 generation.

[0045] The present invention uses mice of the P2 generation to test the efficacy. 3 At 4 hr, mice were randomly divided into groups of 6 and administered the following regimens: Trametinib (2 mg / kg daily via oral gavage) and COTI-2 (10 mg / kg daily via subcutaneous injection). Mouse body weight and tumor size were measured every two days.

[0046] In vivo results Figure 5 As shown, both trametinib and COTI-2 alone inhibited tumor growth in mice, indicating that the in vivo model constructed by the present invention can be used to predict the efficacy of patients with targeted drugs based on mutant genes; at the same time, the combined treatment effect of trametinib and COTI-2 was significantly better than that of single drugs, and had no significant effect on the weight of mice ( Figure 5 B. Figure 5 C. Figure 5 D and Figure 5 These results further suggest that MEK inhibitors combined with p53 activators are a new therapeutic strategy for KRAS and TP53 double-mutant pancreatic cancer.

[0047] 5. Analysis of the mechanism of action of MEK inhibitors combined with p53 activators p53 is a key tumor suppressor, playing a critical role in cell growth, differentiation, and apoptosis through multiple pathways, including cell cycle regulation, apoptosis promotion, genome stability maintenance, and tumor angiogenesis inhibition. MEK inhibitors play a crucial role in cancer therapy by inhibiting MEK kinase activity in the MAPK signaling pathway and blocking signal transduction, thereby inhibiting tumor cell proliferation, inducing apoptosis, and suppressing angiogenesis, invasion, and metastasis. However, MEK inhibitors' regulation of the cell cycle and apoptosis is partially dependent on p53. Mutations in p53 occur in most tumor cells, limiting the efficacy of MEK inhibitors. However, p53 activators can promote the refolding and reactivation of mutant p53 to wild-type form, and thus, combining p53 activators with MEK inhibitors can enhance therapeutic efficacy. Furthermore, there are reports that trametinib, through inhibition of DUSP6, modulates p53 post-translational modifications, inducing increased p53 phosphorylation. Combining trametinib with p53 activators further enhances p53 activity, leading to more pronounced induction of p53 transcriptional targets.

[0048] This study established a dual-model drug screening platform using PDO in vitro and PDX / PDOX in vivo models. Based on next-generation sequencing results from patient tissue samples, the dual models were used to screen for effective mutation-targeted drugs. The screening results revealed that the combination of a MEK inhibitor and a p53 activator is a novel treatment strategy for pancreatic cancer patients with both KRAS and TP53 mutations.

[0049] Although preferred embodiments of the present invention have been described, additional changes and modifications to these embodiments may occur to those skilled in the art once the basic inventive concepts become known.

[0050] Obviously, those skilled in the art may make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if such modifications and variations fall within the scope of the claims and their equivalents, the present invention is intended to include such modifications and variations.

Claims

1. Application of MEK inhibitors combined with p53 activators in the preparation of drugs for the treatment of pancreatic cancer.

2. The use of the MEK inhibitor combined with the p53 activator in the preparation of a drug for treating pancreatic cancer according to claim 1, characterized in that: The MEK inhibitor is trametinib, and the p53 activator is COTI-2; The structural formula of COTI-2 is: 。 3. Use of the MEK inhibitor combined with the p53 activator according to claim 2 in the preparation of a drug for treating pancreatic cancer, characterized in that: The trametinib cooperates with COTI-2 to inhibit the proliferation of tumor cells and reduce tumor volume.

4. Use of the MEK inhibitor combined with the p53 activator in the preparation of a drug for treating pancreatic cancer according to claim 1, characterized in that: The pancreatic cancer is KRAS and TP53 double-mutant pancreatic cancer.

5. A method for constructing an in vivo and in vitro dual-model pancreatic cancer drug screening platform, characterized in that: The steps include: Construction of a PDO in vitro model: Obtain pancreatic cancer tumor tissue samples, digest the pancreatic cancer tumor tissue samples to obtain single pancreatic cancer tumor cells, and use 3D culture methods to culture them to obtain organoids, namely the PDO in vitro model; In vivo model construction: Transplanting ex vivo pancreatic cancer tumor tissue samples into mice to construct an in vivo model; The PDO in vitro model and in vivo model together constitute an in vivo and in vitro dual-model pancreatic cancer drug screening platform; The adenocarcinoma drug comprises the MEK inhibitor according to claim 1 in combination with a p53 activator.

6. The method for constructing an in vivo and in vitro dual-model pancreatic cancer drug screening platform according to claim 5, characterized in that: The in vivo model construction process is as follows: ex vivo pancreatic cancer tumor tissue samples are subcutaneously transplanted into mice to construct an in vivo pancreatic cancer PDX model; or, organoids are resuspended and subcutaneously injected into mice to construct an in vivo PDOX model.

7. A method for screening drugs for treating pancreatic cancer, characterized in that: The steps include: The drug screening platform constructed according to the construction method of claim 5; First, the drug to be tested is applied to the PDO in vitro model and the efficacy is tested to screen for synergistic drug combinations. The synergistic drug combinations screened out are applied to in vivo models and subjected to efficacy testing to screen for drug combinations that have inhibitory effects on tumor growth.

8. The method for screening drugs for treating pancreatic cancer according to claim 7, characterized in that: The drug to be tested is any one of a MEK inhibitor and a p53 activator or a combination of both.

9. The method for screening drugs for treating pancreatic cancer according to claim 8, characterized in that: MEK inhibitors are trametinib or selumetinib; The p53 activator is COTI-2 or APR246.

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