The Mechanism Of MLL2 Promoting The Development Of A549 Lung Cancer Cells And Bioinformatics Research Of Radish Seed Grain Inhibiting A549 Lung Cancer Cell

Object: Lung cancer poses great harm to human health and life, and the five- year survival rate of lung cancer is less than 15%, which is the main cause of cancer death. Many carcinogens can be activated or inhibited by oncogenes and tumor suppressor genes to promote the transformation of living cells into cancer cells. MLL2 exists in various epithelial and tissue cancer cells, such as prostate cancer, colon cancer, lung and liver cancer cells are found. Because the methylation of Cp G island of MLL2 gene promoter in these tumor cells significantly increased, so it is considered to be a tumor gene. This study mainly about MLL2 effects on lung cancer cell research, MLL2 gene induced by human lung adenocarcinoma A549 cell proliferation, migration, and invasion possible mechanism was discussed, and to study the effects of MLL2 gene in lung cancer on histone H3 and H4 lysine amino acid residues of methyl, the possible related genes and signal transduction pathway is analyzed by bioinformatics methods.Methods: We studied the effects of two A549 lung cancer cells on the biological behavior of lung cancer cells, which were constructed over expression and gene silencing of MLL2. We transfected the plasmid containing MLL2 gene by liposome, and use RT-PCR, Western Blot, CCK-8 cell assay to test A549 lung cancer cell proliferation and colony formation. Then, we used fluorescence quantitative PCR(FQ-PCR) to detect MLL2, MMP-2(matrix metalloproteinase-2), PKR(double chain RNA dependent protein kinase) m RNA expression, Western Blot to detect PKR of MLL2 and MMP-2 expression. In order to determine the proliferation, migration and invasion of A549 cells, Transwell were carried out. Then, the over expression and silencing MLL2 plasmid was transfected into human lung adenocarcinoma A549 cells. Using Western blot and immunofluorescence, we test MLL2 of h3k4me3 and H3k4me2, H3k4me1, h3k9me3, H3k9me2, H3k9me1, H3k27me3, H3k27me2, H3k27me1, H3k36me3, H3k36me2, H3k36me1 and H4k20me3 methylation status. Finally, we use R/Bioconductor to analyze and dig the data of gene chip. Download GEO contains radish seed before and after treatment of A549 lung cancer cells of the original data, and then standardized processing, quality control, the different gene screening and analysis, go analysis, clustering and path summary, further analysis of gene regulatory network and molecular interactions.Results: We have successfully constructed the overexpression MLL2 A549 cells. MTT assay was used to detect the migration and found that the cells overexpressing the MLL2 gene, and empty vector group and the control group were compared to the expression of a significant increase in cell invasion and migration of the MLL2, overexpressing MLL2 weakly the adhesion between the same cells and increase heterogeneous cells stick supplementary provisions, and accelerated proliferation and increased colony formation rate. In addition, MLL2 induced MMP-2 m RNA expression increased significantly; the expression of P-PKR protein decreased; PKR m RNA expression had no significant difference compared with the control group and empty vector group. Blot western analysis is showed that MLL2 caused the expression of H3K9me3 weakened, silence MLL2 enhanced H3K9me3 expression, and H3 histone 20 and H4 group protein 4, 27, 36 sites of methylation status has no significant difference. Immunofluorescence showed that MLL2 enhanced by H3K9me3, which was consistent with the results of western blot. Finally, through the results of bioinformatics, we found that the A549 lung cancer cells and MLL2 related genes were down regulated after the treatment of radish seeds.Conclusion: We found that overexpression of MLL2 can promote the growth of A549 lung cancer cells, promote MMP-2 and PKR phosphorylation and proliferation, migration and invasion of lung adenocarcinoma A549 cells. Moreover, lung cancer gene MLL2 has the function of H3K9me3 methylation, and there is no methylation of other histon proteins. Finally, through bioinformatics, we found that the treatment of radish seeds can inhibit A549 lung cancer cell MLL2 related genes and help to inhibit the development of lung cancer cells.