论文摘要:
Objective
Cancer stem cells(CSC)is regarded to be a primary cause in cancer development and progression. It remains unknown whether onco-proteins of high-risk human papillomavirus(HPV) contribute to the maintenance of the stemness of cervical CSC. The aim of our study is to identify the effect of HPV16 E7 and involved mechanism in the maintenance of stemness of cervical CSC.
Methods
Serum-free culture was used to enrich cervical CSCs from SiHa and CaSki cells. CSC markers expression, tumor formation, and drug resistance were detected to assess stemness of cells. RNA-Seq was conducted to identify differentially expressed genes between cervical CSCs with and without HPV16 E7 knock-down. Computer model, CO-IP, and gene function experiment were used to verify downstream signaling pathway of HPV16 E7.
Results
We identified a population of cells that highly expressed OCT4 and SOX2 and exhibited self-renewal, tumor formation and drug resistance. The expression level of OCT4 and SOX2 were significantly decreased in E7 knock-down cells (both P<0.05). During 841 differential expression genes between SiHa stem cells with and without E7 knockdown, APH1B was found, by KEGG and GO analysis, to participate in E7 maintains stemness in cervical CSCs. CO-IP and pull-down showed that APH1B could be directly combined by E7.
Conclusion
HPV16 E7 via targeting APH1B maintains of the stemness of cervical cancer stem cells and APH1B might be a potential diagnostic biomarker or therapeutic target.