HELQ Reverses The Malignant Phenotype Of Osteosarcoma Cells Via CHK1-RAD51 Signaling Pathway

Objective:To investigate the effect and mechanism of HELQ on osteosarcoma cells malignant phenotype and DNA damage repair.Methods:The lentivirus-vectors(Lv-shHELQ and Lv-HELQ)targeting HELQ gene were constructed,as well as a negative lentivirus-vector.All lentivirus-vectors were identified by bases and then transfected,respectively,to human osteosarcoma cell line 143 B and U2-OS,with negative lentivirus-vector transfecting cells acting as negative control group.Cell invasion,migration,proliferation and the level of DNA damage were investigated using Transwell,wound healing,CCK8 and Comet assay.The HELQ mRNA and protein expression were investigated by using fluorescent quantitative PCR and western blot analysis.Furthermore,protein expression levels of CHK1 and RAD51 were also measured by western blot analysis.Result:The expression of HELQ mRNA was significantly lower in U2-OS and 143 B cells,but the expression of HELQ protein was significantly higher in U2-OS and 143 B cells,compared to HOB cells.The invasion,migration and proliferation abilities were significantly higher in the cells transfected by the Lv-shHELQ and significantly lower in the cells transfected by the Lv-HELQ,the level of DNA impairment is significantly lower in the OS cells transfected with Lv-HELQ but significantly higher in the OS cells transfected with Lv-shHELQ,compare to the negative control.HELQ,CHK1 and RAD51 protein expression levels were higher in cells transfected with Lv-HELQ but lower in cells transfected with Lv-shHELQ,compare to the negative control.Conclusion:HELQ may involve in OS cells malignant phenotype and DNA repairing via activating the CHK1-RAD51 signaling pathway.