The Study On Expression And Function Of Cancer Imprinting Gene PEG10 Regulated By Hepatitis B Virus

Chronic hepatitis B refers to chronic hepatitis symptoms caused by HBV virus infection in human liver tissue.In general,HBV is mainly transmitted by the body fluid(blood,lymph,cerebrospinal fluid and other tissue fluid,semen).The virus has a great ability of transmit.It is reported that there are 240 million people infected by HBV,and about 700,000 people die every year from the complications caused by chronic hepatitis B.Fortunately,there is an effective vaccine to prevent human beings from infection by HBV,but there are still many patients infected by HBV cause no-responsing to HBV vaccine or not being vaccinated.The interactions between the proteins from HBV and human immune mechanism,as well as the replication mechanism of HBV are still unclear.There are some studies reveal that the HBV patient has a several times risk to come to liver cancer than normal person.HBV involved in the occurrence of liver cancer mainly includes two aspects:On the one hand,long-term HBV infection makes liver cells to be repeatedly attacked by inflammation.Repeated injury and repairmen may lead to fibrosis of normal tissue lesions(commonly known as cirrhosis),as it gets worse,it comes to liver cancer.On the other hand,a series of HBV replication in the human body led to the activation of the proto-oncogene in normal cells,or change the apparent inheritance of cells to induce cancer.PEG10(paternally expressed 10)is a cancer imprinted gene.Most of the current researches for this protein are focused on its relationship with cancer.It is already known that PEG 10 has a close relationship with malignant tumors,such as liver cancer,pancreatic cancer.High expression of PEG10 was observed in tumor tissue,while in the normal tissue,PEG10 expression is very low.It is reported that PEG10 may be related to the occurrence,migration and proliferation of cancer,functioned as the target protein of other proteins,such as C-myc,E2Fs and so on.These two proteins act directly on the upstream regulatory region of the PEG10 genome,which mediates the expression of PEG 10,and may attend the occurrence of cancer.In this study,we did an analysis based on databases of HBV-infected patients and found that there may be a close relationship between HBV replication and PEG10 expression.We detected expression of PEG 10 in different liver cancer celllines,and found that infection with HBV can increase the expression of PEG10.Different HBV protein components have different effects on the up-regulation of PEG10,and the effect of HBsAg is most significant.Furthermore,we tested the effect of PEG10 on the proliferation and migration of hepatocarcinoma cells by over expression or down-regulation of PEG 10 in HBV infected hepatocytes.It was found that PEG10 did involve in the proliferation and migration of HBV-infected tumors.Finally,we detected the HBeAg?HBsAg by ELISA and RT-PCR.It was also found that increased expression of PEG 10 also up-regulated HBV replication.These results suggest that HBV may promote the proliferation and migration by inducing high expression of PEG 10 in targeted cells,and PEG 10 can positively feed to further promote the HBV replication and contribute to the progression of HBV infection.