| Background: Colorectal cancer(CRC)is the world’s third largest malignant tumor,with more than 1.2 million new cases and over 600,000 death toll each year.In recent years,the incidence of CRC in younger adults has been significantly increasing.Although the diagnosis and treatment have made great progress,tumor metastasis and recurrence make the survival rate of colorectal cancer hardly satisfying.Therefore,it is very important to do in-depth studies on the molecular mechanism of occurrence and metastasis of colorectal cancer,which will offer theoretical basis for gene targeted therapy.KRAB zinc finger protein(KZNF)is an important transcription factor in the human genome.KZNFs participate in cell proliferation,differentiation,apoptosis,tumor formation and other important life processes.ZER6 is a typical KZNF.Transcripts from the ZER6 gene can have alternate 5’ exons and encode either a p71 or p52 isoform.Current studies have shown that p52-ZER6 protein interacts strongly with ERα in the presence of estradiol,whereas the p71-ZER6 isoform has a HUB-1 amino-terminal domain that inhibits the interaction with ERα.ZER6 can regulate the development of hormone-sensitive breast cancer through regulating the relative level of expression of two distinct isoforms.However,the role of ZER6 in colon cancer remains unclear,and the effect of ZER6 on HCT116 cell biological behavior has not been reported yet.Objectives: 1.Understanding the relation between the expression of ZER6 in clinical tissues and colon cancer development.2.Exploring the function of ZER6 in HCT116 cell growth and studying its mechanism.3.Comparing the different effect of p52-ZER6 and p71-ZER6 on HCT116.Methods: 1.Detecting the expression of ZER6 in colon cancer tissues by using RT-PCR and Western Blot.2.Detecting the cell growth of HCT116 by CCK-8,Crystal Violet Staining and EdU incorporation assay while detecting the cell cycle by FCM.3.Exploring the possible pathways that ZER6 could involve by using DoubleLuciferase Reporter assay,RT-PCR and Western Blot.Results: 1.RT-PCR and Western Blot demonstrated that ZER6 high expressed in colon cancer tissues both in RNA and protein levels.2.According to the results of CCK-8,Crystal Violet Staining,EdU incorporation assay and FCM experiment,ZER6-suppression induced G0/G1 phase arrest and eventually suppressed cell proliferation rate.3.Double-Luciferase Reporter assay,RT-PCR and Western Blot demonstrated that ZER6-suppression reduced Cyclin D1 and Cyclin E2 expressions via p21 activation.4.We found p71-ZER6 knockdown had no significant effect on p21,and p52-ZER6 knockdown promoted the expression of p21,then inhibited the expression of Cyclin D1 and Cyclin E2,eventually reduced cell proliferation rate.p52-ZER6 overexpression inhibited expression of p21,and then increased the expression of Cyclin D1 and Cyclin E2.Conclusion: 1.ZER6 overexpressed in colon cancer,so the expression of ZER6 can be used as a biomarker to diagnose colon cancer.2.p52-ZER6 inhibited the proliferation of HCT116 cells,suggesting that p52-ZER6 can serve as a potential molecular target for the treatment of colon cancer,and provide a theoretical basis and scientific guidance for the diagnosis and treatment of colon cancer. |
