Function And Mechanism Of GADD45α Inhibits The Proliferation Of Rat Hepatoma Cells CBRH-7919

Growth arrest and DNA damage induction 45α(GADD45α)is a stress-inducing protein that plays an important role in cell survival,death,chromatin assembly,genomic stability,and DNA repair.The protein expressed by GADD45α responds to environmental stress by MTK1/MEKK4 kinase-mediated activation of the p38/JNK pathway.The transcriptional expression pattern of GADD45α is mediated by both p53-dependent and p53-independent mechanisms.In this thesis,through previous bioinformatics analysis,it was found that the GADD45α gene was expressed in low abundance in various cancer tissues.GADD45α has significant differences in the expression levels of cancer tissues and adjacent tissues.However,the expression of GADD45α was abnormally increased during the process of liver diseases and liver cancer caused by unfavorable factors such as DNA damage and environmental stress.The TCGA tumor database analysis of liver cancer found that patients with high expression of GADD45α had a higher survival rate as well as lower recurrence and metastasis.Some evidence preliminarily indicates that GADD45α played an important role in the development of liver cancer.Therefore,in this thesis,the rat hepatoma cells CBRH-7919 and the rat liver cells BRL-3A treated with a continuous low concentration of MC-LR were used as the main experimental materials to explore the specific functions and molecular regulation mechanism of GADD45α in the development of liver cancer.In this thesis,experimental methods such as GADD45α gene overexpression and siRNA gene knockdown were used.Cell viability was detected by MTT,it was found that overexpression of GADD45α inhibited the viability of hepatoma cells.EDU was used to detected cell proliferation,the results showed that overexpression inhibited the proliferation of liver cancer cells,The result of invasion and metastasis test indicated that overexpression of GADD45α slowed the invasion and metastasis of the cells,while interference with the expression of GADD45α promoted the invasion and metastasis of hepatoma cells.Flow cytometry was used to detect cell apoptosis and cycle.It was found that GADD45α overexpressing significantly blocked the cell cycle progression and promote apoptosis in hepatoma cells.While knockdown the expression of GADD45α promoted cell cycle progression and inhibits apoptosis.The signal pathway diagram in which GADD45α may play a role was analyzed and drawn through online websites such as IPA and KEGG.The results of qRT-PCR and Western-blot showed that the gene and protein levels of P38,JNK,MAPK,AKT,and other signaling pathways changed significantly.GADD45α may play a regulatory role in the development of liver cancer through P38,JNK,MAPK,AKT,and other related signaling pathways.