Preliminary Study Of The Mechanism For LncRNA MEG3 Inhibiting Inproliferation And Invasion Of Hepatocellular Carcinoma Cells By Up Regulating P53

Background: lncRNA is a kind of long-chain RNA with length over 200 nucleotides but does not have protein translation function.Most of them are transcribed by RNA polymerase Ⅱ.Although lncrna can not encode protein,it plays an important role in many important biological regulation processes,such as chromatin modification,X chromosome silencing,transcription activation,epigenetic and so on.lncRNA can participate in the development of tumor through gene transcription regulation,phenotype genetic regulation,nucleosome remodeling and signal transduction between cells,such as the proliferation,migration,local infiltration,and metastasis of tumor cells,and play a similar role in cancer genes or tumor suppressor genes.Many studies have shown that the abnormal expression of lncrna is closely related to the occurrence and development of tumor metastasis,angiogenesis,immunotherapy resistance and prognosis.The relationship between hepatecelllar carcinoma(HCC)and the abnormal expression of lncrna was studied.The expression of lncrna between liver cancer and adjacent tissues was detected by real-time quantitative PCR.The expression of lncRNA MEG3 was significantly different between the two tissues.By constructing the expression vector of lncrna MEG and overexpression in the hepatoma cells,we found that meg3 can extend the half-life of p53 protein by interacting with p53 protein,promote the transcription activity of p53,inhibit the proliferation of hepatoma cells and promote apoptosis of HCC cells.In this study,we studied the relationship between lncRNA MEG3 and clinicopathological characteristics in liver cancer and the value of prognosis evaluation.The effects of lncRNA MEG3 on the proliferation and migration of hepatoma cells were also detected by in vitro experiments.On this basis,we have explored the mechanism of lncRNA MEG3 in inhibiting liver cancer by increasing the expression of p53,which provides a theoretical basis for further clinical transformation.Method:1.To detect the expression of lncRNA MEG3 in liver cancer and adjacent tissues: the expression of lncRNA MEG3 in liver cancer and fresh tissues was detected by real-time quantitative PCR;the expression of lncRNA MEG3 in 60 patients with liver cancer and adjacent tissues was detected by real-time quantitative PCR,and the relationship between lncRNA MEG3 and clinicopathological characteristics and survival prognosis was analyzed by means of computer.2.The overexpression vector of lncRNA MEG3 was constructed,and the effect of overexpression of lncRNA MEG3 on the proliferation of different hepatocarcinoma cells was detected by CCK8 experiment;the effect of lncRNA MEG3 on the migration and invasion of different hepatocarcinoma cells was detected by Transwell experiment.3.The effect of overexpression of lncRNA MEG3 on the expression of p53 in different liver cancer cells was detected by Western blot.Result:1.The expression of lncRNA MEG3 in 15 hepatoma clinical samples was detected by QRT PCR.The results showed that the expression of lncRNA MEG3 in the liver cancer tissue was significantly decreased compared with that of the adjacent tissues(P < 0.01)2.Compared with TNM stage Ⅰ and Ⅱ,the expression of lncRNA MEG3 in liver cancer tissues of stage Ⅲ and Ⅳ patients was significantly lower(p=0.0184);the expression level of lncRNA MEG3 was also negatively correlated with the lymph node metastasis of liver cancer(p=0.0287);the expression of lncRNA MEG3 was not significantly correlated with the age,gender and differentiation of liver cancer tissue.3.The relationship between the expression of lncRNA MEG3 and prognosis of liver cancer was analyzed by Kaplan Meier.The results showed that the total survival period of patients with low expression of lncnrna MEG3 was shorter than that of patients with high expression of lncrna MEG 3(p=0.006).4.CCK8 results showed that overexpression of lncrna meg3 in Hep G2 and Huh7 cells significantly inhibited the proliferation of hepatoma cells.5.Transwell assay showed that up-regulation of lncrna-meg3 expression in Hep G2 and Huh7 cells significantly reduced the number of migration and invasion cells.6.WB results showed that the expression of p53 protein was significantly increased by the high expression of lncRNA MEG3 in different hepatoma cells.The results showed that lncRNA MEG3 may participate in the development of tumor by affecting the expression of p53.Conclusion1.The expression of lncRNA MEG3 in liver cancer tissue was significantly lower than that in the adjacent tissues,and the low expression of lncRNA MEG3 patients had higher malignant degree and poor prognosis.It suggested that lncRNA MEG3 could be used as a potential marker for the classification and adverse prognosis of liver cancer;2.Overexpression of lncRNA MEG3 in hepatoma cells can inhibit the proliferation,migration and metastasis of HCC cells;3.lncRNA MEG3 may inhibit the proliferation and migration of hepatoma cells by increasing the expression of p53,which is the potential target of molecular targeted therapy for liver cancer.