Expression Of ZHX2 Gene In Hepatitis B Virus-Associated Hepatocellular Carcinoma

BackgroundLiver cancer is one of the malignant tumors that threaten the survival of human-beings.Most of the primary liver cancer is hepatocellular carcinoma?HCC?.It is the fifth most common malignant tumor in men and the eighth most common malignant tumor in women.And it is also the second largest cause of cancer death in the world.Chronic hepatitis B virus?HBV?infection is one of the major risk factors worldwide.According to a statistics,there were 770000 new cases of liver cancer in the world in 2012,of which 56%were related to HBV.At present,the global incidence of HCC is increasing.According to 2015 statistics,about 3.50%of the global population,or 257 million people,are infected with HBV,with a particularly high prevalence in Asia and sub-Saharan Africa,with 4.7 million new cases of chronic hepatitis B?CHB?reported each year.Many patients with chronic hepatitis B are at risk of developing liver cirrhosis and liver cancer,which is still a highly related disease in Asia.At present,the effective treatment of patients with liver cancer is only ideal in the early stage of the disease with low tumor burden.At this stage,surgical resection,liver transplantation and local ablation are all likely to achieve a cure,and patients after treatment are estimated to survive for more than 5 years.Therefore,early detection,early diagnosis and early treatment of HCC are still very important for the prognosis.Hepatitis B virus?HBV?infection is the most common known cause of HCC.HCC often has no obvious symptoms in the early stage and is often found in the late stage,resulting in a poor prognosis.HCC is an invasive cancer,early detection and treatment has a great impact on the prognosis of HCC.Most HCC cases are accompanied by chronic hepatitis B virus?HBV?infection,while other non-HBV factors may increase the risk of liver cancer in CHB patients.HBV plays both direct and indirect roles in the occurrence of HCC.The direct carcinogenic effects of HBV include integration into the host genome,resulting in DNA gene deletion,cis/trans activation,translocation,production of fusion transcripts and general genomic instability,as well as multiplicity of viral transcripts?HBsAg and HBx?.In the process of HBV infection,repeated liver inflammation caused by host immune response can lead to liver fibrosis and cirrhosis,accelerate hepatocyte turnover,.Thus promote the accumulation of variation,and eventually lead to canceration.Because HBV is not a direct cytopathic effect,it is generally believed that host response to virus-infected hepatocytes mediates hepatocyte damage,and long-term chronic liver inflammation and weak immune-mediated virus clearance lead to the occurrence and development of liver cirrhosis and liver cancer.At the same time,chronic hepatitis B is a dynamic disease.Patients with chronic hepatitis B often show different serum ALT activity,HBVDNA expression and HBV antigen levels in different clinical stages.It is generally believed that cancer is caused by a variety of factors,including genetic mutations and epigenetic changes.This may cause abnormal expression of corresponding mRNA in structure or quantity,which will affect the normal biological response and eventually lead to carcinogenesis.HBx is considered to be the most important factor in HBV-induced hepatocellular carcinoma.Zinc finger and homeobox 2?ZHX2?are transcriptional suppressors,which were first discovered by Olsson in 1977 and play a transcriptional inhibitory role mainly in the nucleus.ZHX2 was first discovered as a negative regulatory gene of AFP expression,and then its tumor suppressor gene function was found.There is hypermethylation of ZHX2 gene promoter in hepatocellular carcinoma tissue and HepG2 cell line,which leads to down-regulation of ZHX2 mRNA expression.ZHX2 gene is involved in the inhibition of liver cancer from many aspects.ObjectiveIn this study,Real-time quantitative polymerase chain reaction?RT-qPCR?was used to evaluate the relationship between the expression of ZHX2 gene mRNA in Peripheral blood mononuclear cells?PBMC?and hepatitis B virus-associated hepatocellular carcinoma,and to analyze the correlation between ZHX2 mRNA expression and the condition and severity of patients with hepatitis B virus-associated hepatocellular carcinoma.MethodsThis study inculded 76 HCC patients?HCC group?,52 CHB patients?CHB group?,and 26 healthy controls?HCs group?.Collected fasting peripheral blood samples,and isolated PBMC RNA from blood samples,reverse transcribed PBMC RNA.RT-qPCR was used to detect the mRNA expression level of ZHX2 gene in PBMC of all subjects.Results1.Comparison of the basic clinical characteristics of experimental subjects:There was no significant difference in gender?P=0.762?and age?P=0.605?among the three groups,but there were significant differences in ALT?P=0.004?,AST?P<0.001?,GGT?P<0.001?,AKP?P<0.001?,TBIL?P<0.001?and ALB?P<0.001?.There were significant differences in HBeAg?P=0.021?,AFP?P<0.001?,INR?P=0.032?,PT?P=0.011?and PTA?P=0.004?between HCC group and CHB group,but there was no significant difference in HBsAg?P=0.418?and HBVDNA?P=0.386?.2.There were evidently differences in mRNA level of ZHX2 gene among HCC group,CHB group and HCs group?P<0.001?.ZHX2 mRNA level in HCC group was evidently lower than in CHB group?Z=-4.466,P<0.001?and in HCs group?Z=5.218,P<0.001?.ZHX2 mRNA level in CHB group was lower than in HCs group?Z=-2.507,P=0.012?.3.In HCC patients,the ZHX2 mRNA level was not correlated with HBsAg level?Spearman's r=-0.003,P=0.980?.There were no significant difference in ZHX2 mRNA expression level between HBeAg?-?group and HBeAg?+?group?Z=-0.341,P=0.733?.There were no significant difference in ZHX2 mRNA level between HBV DNA?-?group andHBV DNA?+?group?Z=-0.688,P=0.491?.The ZHX2 mRNA level were not correlated with ALT?Spearman's r=0.042,P=0.721?,AST?Spearman's r=-0.018,P=0.882?,GGT?Spearman's r=-0.012,P=0.919?,AKP?Spearman's r=0.041,P=0.731?,TBIL?Spearman's r=0.158,P=0.181?,ALB?Spearman's r=-0.092,P=0.440?,AFP?Spearman's r=-0.085,P=0₄66?,INR?Spearman's r=0.223,P=0.057?,PT?Spearman's r=-0.199,P=0.085?and PTA?Spearman's r=-0.206,P=0.081?in HCC patients.4.In HCC patients,there were no evidently difference in ZHX2 mRNA level between LC?+?group and LC?-?group?Z=-0.458,P=0.647?.There were no significant difference in ZHX2 mRNA level between CTP staging A group and CTP staging B group and CTP staging C group?P=0.495?.there were no significant difference in ZHX2 mRNA level between TNM staging?I+II?group and TNM staging??+??group?Z=-0.726,P=0.468?,ZHX2 mRNA level in Tumor size?<5cm?group were higher than in Tumor size??5cm?group?Z=-0.780,P=0.436?.ZHX2 mRNA level in vascular invasion?-?group were higher than in vascular invasion?+?group?Z=-2.281,P=0.023?.Conclusion1.The ZXH2 mRNA level in HCC patients is lower than in CHB patients and healthy controls,which suggests that the expression level of ZHX2 mRNA may be related to the occurrence of hepatitis B virus-associated hepatocellular carcinoma.2.ZHX2 mRNA level in Tumor size?<5cm?group were higher than in Tumor size??5cm?group,and ZHX2 mRNA level in vascular invasion?-?group were higher than in vascular invasion?-?group.Which suggests that ZHX2 may be related to the severity of HCC.