Effect Of PRDX2 On HCC Cell Biological Behaviours,and Its Association With Patients' Prognosis

Objective Hepatocellular Carcinoma(HCC)is a highly malignant gastrointestinal disease.Currently,early diagnostic biomarkers possessing high sensitivity and specificity are still lacking,thus making it very difficult to improve the overall survival of HCC patients.The oxidative stress pathway involves a large number of regulatory factors which present complicated interactions,thus making it hard to appreciate the full picture of resulting mechanism.Different tumor types,individual variations,and different stages where tumor sits are making huge obstacles to make early diagnosis and treatment and ultimately produce enormous impact on HCC patients' survival time.During different phases of cancer development,HCCs do not necessarily exhibit unanimous malignant phenotype.HCCs themselves can develop different differentiation types and form different subgroups,then the stacked phenotypes which derives from those subtypes will determine the final HCC phenotype.This feature of HCC is resulting in phase-dependent difference to oxidative stress pathway regulation.By using proteomics methods,this study aims at screening differentially expressed protein marker profiles in heterogeneous HCC tissues.Bio-informatic tools will be used to analyze protein functions and related signaling pathways.After it is clarified whether PRDX2 is differently expressed in heterogeneous HCC tissues,further studies will be conducted to investigate the PRDX2 expression differences between HCC issues and normal liver tissues,and as well as between HCC cell lines and normal liver cell lines.Lentivirus transfection and cell function tests are used to examine the effects that how PRDX2 affects biological behaviors of HCC which represented by proliferation and migration abilities.Tissue microarrays will be used to investigate PRDX2 expression levels in HCC tissues and para-cancer tissues,the correlation between PRDX2 expression and patients' survival will be studied,and whether PRDX2 is a independent prognostic factor will be analyzed.In summary,this study aims at making better understanding concerning the role that oxidative stress pathway and its regulatory factors play in the development of HCC,and their impact on the clinical prognosis of HCC patients.Methods A total of 20 tumor samples were collected from HCC patients who had undergone radical surgery in 1st Hospital of Lanzhou University,among which 10 were highly differentiated samples and others were poorly differentiated samples.The two-dimensional gel electrophoresis was applied to separate differential protein spots;MALDI-TOF-MS was applied to perform mass spectrum identification.Bioformatic methods were used to predict protein functions and pathways related to tumor phenotypes.A total of 180 cases of matched HCC tissues and their adjacent normal liver tissues were collected from patients who had underwent radical surgeries during 2009 to 2010;clinical follow-up data were collected,and eventually 176 cases were enrolled;tissue microarrays were established accordingly,immunohistochemical method was used to clarify the PRDX2 expression levels of HCC tissues and normal liver tissues;the patients were then divided into 2 subgroups depending on their high or low PRDX2 expression levels in HCC tissues;the correlation between different PRDX2 expressions and clinical index of HCC patients was studied by using several statistical methods.The correlation between PRDX2 expression levels and overall survival and disease-free survival was also analyzed.HCC cell lines with silenced PRDX2 were established,then the CCK-8 cell proliferation and transwell migration experiments were used to test the proliferation and migration alterations.Results Results from proteomics study showed that PRDX2 was differently expressed in those heterogeneous HCC tissues.Bioformatic analysis suggested that PRDX2 is related to the prognosis of HCC patients and is involved in the regulation of multiple signaling pathways.The results of WB and q-RT-PCR showed that the mRNA expression levels of PRDX2 in HCC cell lines were lower than that of normal liver cell lines.PRDX2 protein expression levels in HCC tissues were lower than that of the adjacent normal liver tissues.The results from microarrays showed that PRDX2 was universally down-regulated in HCC tissues,while in para-cancer tissues PRDX2 showed universally high expressions.The OS and DFS of HCC patients who had higher PRDX2 expression were longer than those with low PRDX2 expressions.PRDX2 is an independent prognostic factor.Cell function test results showed that the proliferation and migration ability of HCC cell lines increased after PRDX2 silencing.Conclusion The PRDX2 expression levels in heterogeneous HCC tissues were different and were correlated with prognosis of patients.PRDX2 is universally down-regulated in HCC.PRDX2 protein expression level in HCC tissue was positively correlated with patients' OS and DFS.PRDX2 is an independent predictor.The migration and proliferation of HCC cell lines were increased after PRDX2 silencing.PRDX2 is a significant biomarker for HCC.