Effect Of MYL9 Gene On Proliferation And Migration Of Non-small Cell Lung Cancer

Objective: Among all malignant tumors in China,lung cancer is the most common tumor.According to histological type and biological characteristics,lung cancer can be roughly divided into two types,which are small cell lung cancer(SCLC)and non-small cell lung cancer(NSCLC).The most common type of lung cancer in the clinic is NSCLC,which accounts for 80% to 85% of the total number of lung cancers.Because the onset of lung cancer is very insidious,and lung cancer lacks obvious specific symptoms at the early stage,and is prone to lymphatic and hematogenous metastasis,most patients have entered the advanced stage when the lung cancer is diagnosed,and the treatment effect and prognosis are poor.Previous lung cancer patients treated with surgery,radiotherapy and chemotherapy,but that were not effective.In recent years,targeted therapy and immunotherapy have gradually been applied to the clinic and have achieved very good results.However,due to various reasons such as drug resistance,the five-year survival rate of lung cancer is still relatively low,and the overall prognosis is still poor.The pathogenesis and development mechanism of lung cancer are complicated.Although more and more studies are constantly being explored and verified,the specific mechanism has not yet been clarified,and the prevention and treatment of lung cancer are still difficult.In order to effectively prevent lung cancer and treat lung cancer,and improve the survival rate and quality of life of lung cancer patients,our research needs to focuse on the continuously explore the specific mechanism of lung cancer occurrence and development,and to seek to a key target for lung cancer of prevent this specific mechanism.Then we can design relevant diagnostic tools and treatments based on these targets to effectively inhibit the occurrence and development of lung cancer.In the previous research,we used bioinformatics methods such as gene enrichment to screen out one of the key genes closely related to the occurrence and development of NSCLC in the gene chip database,myosin regulatory light chain 9(MYL9)gene.In order to further clarify the biological function of MYL9 gene,this study silenced the MYL9 gene in NSCLC H1299 cell line by using RNA interference technology.After that,we detected the proliferation and migration of H1299 cells which had been silencing the MYL9 gene.We explored the effect of MYL9 gene on the proliferation and migration of H1299 cell line,and explored potential new targets for targeted therapy of lung cancer.Methods:(1)Lentiviral transfection and silencing of MYL9 gene stable cell line: The experimental cells were NSCLC H1299 cells.Three groups were set up in this experiment,which were control group,negative control group and knockdown group.H1299 cells transfected with pSLLV-U6-zsGreen-puro– MYL9 virus silencing MYL9 gene were knocked down(KD)group,and H1299 cells transfected with pSLLV-U6-zsGreen-puro-NC empty virus were negative control(NC)group,H1299 cells without transfection operation as control(CON)group.(2)We used real-time quantitative PCR to detect the MYL9 mRNA expression level.(3)We used MTT assay to detected the H1299 cells’ proliferation ability.(4)The migration ability of H1299 cells was observed by scratch test.Results:(1)In this study,a stable H1299 cell line that silences MYL9 gene and a stable H1299 cell line transfected with no-load virus were successfully constructed.(2)We used real-time quantitative PCR to detect the MYL9 mRNA expression level.The detection result shows that KD group MYL9 mRNA expression of the gene was the lowest,which was significantly lower than that of the CON group and the NC group(P<0.05).(3)We used MTT assay to determine the proliferation of the three group cells at 24 h,48h,72 h,96h and 120 h.The cell growth curve showed that the three group cells increased with time.The A values at 24 h,48h,72 h,96h and 120 h in the KD group were lower than those in the CON group and the NC group.The difference was statistically significant(P<0.05),suggesting that the proliferative capacity of KD group was significantly decreased.(4)In the scratch test,the scratch areas healing rate of 24 h in the CON group,NC group and KD group were(33.98±0.89)%,(21.68±1.12)%,(8.77±2.01)%,and the scratch areas healing rates of 48 h were(83.75±3.25)%,(82.51±13.64)%,(28.43±2.12)%,the healing rate of scratch areas in KD group at 24 h and 48 h were significantly lower than that in CON group and NC group,the difference was statistically significant(P < 0.05).It is suggested that the migration ability of cells in KD group is significantly reduced.Conclusion: In this experiment,a lentiviral vector with silenced MYL9 gene was successfully constructed,which was successfully transfected into H1299 cells and stably expressed in H1299 cells.It was confirmed that silencing MYL9 gene can inhibit the proliferation of NSCLC cells and block the migration of NSCLC cells in vitro.This study provides new ideas for the proliferation and metastasis of lung cancer,and may provide new targets for the treatment of lung cancer.