The Molecular Mechanism Of TP53 K351N Mutant In Platinum-resistance In Epithelial Ovarian Cancer

BACKGROUNDOvarian cancer is the most lethal malignancy of the female genital tract.The main reason is that the lack of special clinical symptoms;Second,we have no effective screening methods;Moreover,the majority of ovarian cancer is highly malignant,moreover,a pelvic or abdominal pelvic spread planting is very early,or lymph node metastasis,resulting in most patients with ovarian cancer is in middle-late(?-?)stage before they see doctors.Since 2011,the guideline for patients with advanced ovarian cancer has recommended primary debulking surgery(PDS)followed by platinum-based chemotherapy as the preferred treatment option.For patients who are unable to tolerate PDS or who cannot achieve optimal resection in PDS,the recommended treatment option is platinum-based neoadjuvant chemotherapy followed by neoadjuvant chemotherapy(NACT-IDS).Although,with the advancement and development of surgical techniques and systemic treatments,the overall survival rate of patients with advanced ovarian cancer has hardly changed much in the 30 years since the introduction of platinum drugs.The main reason is the endogenous or acquired drug resistance of tumor cells during treatment.Many studies have confirmed that the NACT-IDS treatment model increases the risk of platinum-derived acquired drug resistance in patients.Regardless of whether endogenous or acquired resistance,it is a mountain to improve the prognosis of patients with ovarian cancer.Therefore,it is very important to further elucidate the mechanism of chemotherapy resistance in ovarian cancer and overcome or avoid drug resistance.In recent years,the rapid development of molecular biology,we may be able to find the answer at the genetic level.OBJECTIVESFrom the molecular level,we explored the relationship between TP53 K351N mutation and EOC platinum resistance,providing theoretical support for clinical drug use.METHODS:The wild-type and mutant P53 plasmids were constructed by us.Through transfection and drug screening,stable expression of wild-type A2780 cell line,stable expression of mutant A2780 cell line were obtained.The results were verified by gene sequencing;Testing the inhibitory effects of cisplatin on stable expression of wild-type A2780 cell line,stable expression of mutant A2780 cell line and A2780 cell line by crystal violet method;Flow cytometry was used to detect the difference in the apoptosis rate of stable expression of wild-type A2780 cell line,stable expression of mutant A2780 cell line and A2780 cell line;The western bolt technique was used to detect the differences in the expression of caspase3,BAX,and Bcl2 of stable expression of wild-type A2780 cell line,stable expression of mutant A2780 cell line and A2780cell line.RESULTS:Cis-platin had growth inhibitory effects on stable expression of wild-type group,mutant group,and blank.However,cisplatin had the weakest inhibitory effect on the mutant group,followed by the blank effect,and had the strongest inhibitory effect on the growth inhibition of the wild-type group.The tolerability of TP53 Mut to cisplatin was 2.65 times higher than that of TP53 Wt(P<0.05).By flow cytometry,the apoptosis rate of the mutant group was the lowest at the same time and the same concentration of cisplatin,followed by the blank group,while the wild type group had the highest apoptosis rate.At 15 hours,the apoptosis rate of TP53 Mut group was 11.4 times that of TP53 Wt group;at 30 hours,the apoptosis rate of TP53 Mut group was 9.55 times that of TP53 Wt group(P<0.05).Apoptotic protein detection,at the same time,the same concentration of cisplatin,mutation group caspase-3 protein and BAX protein expression is the lowest,Bcl2 protein expression is the highest,indicating that TP53 K531 mutation can inhibit its apoptotic activity.In contrast,the wild group could up-regulate the expression of caspase3 protein and BAX protein,down-regulate the expression of Bcl2 protein and increase its apoptotic activity.According to its gray value,the relative expression of activated caspase-3 protein in TP53 Wt group was 1.46 times that of TP53 Mut group,and the ratio of BAX/Bcl2 in TP53 Wt group was 10.78 times that of TP53 Mut group.CONCLUSIONS:In the face of cell damage,the normal P53 gene mediates repair of the cell and repairs the cell,allowing the cell to survive;if it fails to repair the cell damage,it mediates apoptosis.Cis-platin is a cytotoxic drug that mediates cell apoptosis by inhibiting DNA replication and damaging cell membrane structure,preventing P53 from repairing damage.Cisplatin is a cytotoxic drug that inhibits cell DNA replication and damages cell membrane structures.Cis-platin makes the P53 gene unable to repair damage,which in turn mediates apoptosis.The TP53 K351N mutation prevented the cells from mediating normal cell apoptosis even if they were unable to repair them,resulting in resistance to cisplatin in stable expression of mutant A2780 cell line;In clinical work,whether it is the choice of PDS treatment mode or NACT-IDS treatment mode,if the TP53 K351N mutation can be detected before chemotherapy,it can guide the choice of chemotherapy regimen and avoid chemotherapy resistance.