Preliminary Study On MiR-202/LIN28B In Cisplatin Resistance Of Non-small Cell Lung Cancer

Background and Objective: Lung cancer is the most common malignancy with the highest morbidity and mortality in the world.The majority of patients with non-small cell lung cancer(NSCLC)are advanced at the time of diagnosis.Current treatments for lung cancer are rapidly changing,but for advanced patients with non-genetic mutations and treatment progression,Whether it is first-line treatment or palliative treatment,it ultimately needs to return to chemotherapy.The unavoidable problem of lung cancer chemotherapy is cisplatin resistance.A large number of studies have found that there are many non-coding micro RNAs(mi RNAs)that express differences between tumor tissues and normal tissues.mi RNAs inhibit the translation of m RNA through the post-transcriptional regulation by complementary pairing with the target m RNA,thereby forming a complex regulatory network and participating in cell proliferation,apoptosis and other biological processes.Previous studies have found that mi R-202 functions as a tumor suppressor gene in many tumors,and can inhibit tumor development,drug resistance,invasion,and metastasis.At present,the mechanism of cisplatin resistance in NSCLC is not clear.In this study,NSCLC cisplatin-sensitive and drug-resistant strains were used as experimental subjects to observe the biological differences of mi R-202 and its target gene LIN28 B in cell experiments,and to explore mi R-202/LIN28 B.To investigate the effect of cisplatin resistance on non-small cell lung cancer,a potential gene target for reversing cisplatin resistance was sought.Methods: 1.The mi RNA microarray was used to screen differentially expressed mi RNAs in cisplatin-sensitive A549 and drug-resistant A549/DDP.The on-line database was used to predict the target genes and relevant research was searched.The mi R-202/LIN28 B was selected for study.2.Each cell line was constructed by transient transfection and stable transfection,and the expression of mi R-202 and LIN28 B was detected by fluorescence quantitative PCR to verify whether the cell line was successfully constructed.3.In each cell line,cell proliferation,migration,and susceptibility to cisplatin were measured by MTT assay,plate cloning assay,scratch assay,cycle assay,and apoptosis assay.4.Real-time fluorescence quantitative PCR was used to detect the expression of LIN28 B in cancer tissues and corresponding adjacent tissues of NSCLC patients.Clinical data were used to analyze the correlation between clinical characteristics and prognosis of LIN28 B.Results 1.According to the mi R chip results and our research project,the study was performed by mi R-202/LIN28 B through online database prediction and literature search.2.Transient transfection successfully constructed mi R-202 overexpression and interference cell lines;stable transfection successfully constructed LIN28 B overexpression and interference cell lines.3.Through in vitro cell experiments,it was found that over-expression of mi R-202 can inhibit the proliferation and migration of lung cancer cells,and increase the sensitivity of lung cancer cells to cisplatin(P<0.05).Interfering with mi R-202 can promote the proliferation and migration of lung cancer cells.Ability to reduce the sensitivity of lung cancer cells to cisplatin(P<0.05).4.Through in vitro cell experiments,we found that overexpression of LIN28 B can promote the proliferation and migration of lung cancer cells,and can reduce the sensitivity of lung cancer cells to cisplatin(P<0.05).Interfering with LIN28 B can inhibit the proliferation and migration of lung cancer cells,and can Increase the sensitivity of lung cancer cells to cisplatin(P<0.05).5.In vitro cell experiments found that mi R-202 can negatively regulate LIN28 B.6.The study of clinical tissue samples found that LIN28 B was significantly higher in cancer tissues than in adjacent tissues and significantly in tumor size,TNM staging,and postoperative recurrence times.Conclusions: 1.Mi R-202 is involved in the regulation of cisplatin resistance in NSCLC.2.Mi R-202 participates in NSCLC cisplatin resistance by regulating LIN28 B.3.The expression of LIN28 B was significantly higher in cancer tissues than in adjacent tissues.The expression of LIN28 B was significantly different from tumor size and TNM stage.The recurrence time of LIN28B-expressing NSCLC patients was significantly earlier than that of low-expression patients.