Investigating the role of the siRNA on the expression of HPV16 E6 oncoprotein on the proliferation and cell progression of CaSki cells

Abstract

Persistent infection with high-risk Human papillomaviruses (hr-HPV) such as hr-HPV-16 and hr-HPV-18 lead to cervical cancer, the fourth most common cancer in the world. In the present study, we investigated the alteration of E6 oncogene expression by E6-specific short interfering RNA (siRNA), in combination with Oxaliplatin. Methods: The cervical cancer cell line, CaSki, was obtained from Iranian Biological Resource Center, was transfected with E6-siRNA, then treated with Oxaliplatin. The cellular genes such as p53, MMP9, Nanog, and caspases gene expression was assessed by quantitative Real-time PCR. Cell death rate, cell cycle, and cell viability were examined by Annexin V/PI staining, DAPI staining, and MTT test, respectively. Furthermore, the stemness ability and cell metastasis were determined by colony formation assay and scratch test, respectively. Results: The combination of Oxaliplatin and siRNA increased the gene re-expression involved in the p53-dependent apoptosis pathway (increase in apoptosis to 44.2%), and reduced stemness and metastasis ability compared to either siRNA or Oxaliplatin monotherapy. Our results demonstrated that E6-siRNA and Oxaliplatin combination increased the cervical cancer cells’ sensitivity to Oxaliplatin; in contrast, decreased the survival rate, proliferation, metastasis, and consequently escalated apoptosis rate. It also induced cell cycle arrest in the sub-G1, and reduced the chemotherapy drug dosage.