Inhibition of antiviral drug cidofovir on proliferation of human papillomavirus-infected cervical cancer cells

Abstract

In order to evaluate the potential application value of cidofovir (CDV) in the prevention of human papillomavirus (HPV) infection and treatment of cervical cancer, the inhibitory effect of CDV on the proliferation of HPV 18-positive HeLa cells in cervical cancer was preliminarily investigated, using cisplatin (DDP) as a positive control. An MTT assay was used to analyze the effects of CDV and DDP on HeLa cell proliferation. In addition, clone formation assay and Giemsa staining were used to examine the extent of HeLa cell apoptosis caused by CDV and DDP. Flow cytometry was also used to detect the shape and size of apoptotic cells following propidium iodide staining, while western blot analysis identified the expression levels of of E6 and p53 proteins in HeLa cells. A cell climbing immunofluorescence technique was used to locate the subcellular position of p53 in HeLa cells. The results demonstrated that CDV and DDP inhibited the proliferation of HeLa cells in a concentration- and time-dependent manner. Flow cytometry showed that CDV and DDP treatments resulted in cell arrest in the S-phase, and triggered programmed cell death. Furthermore, western blot analysis revealed that CDV and DDP inhibited E6 protein expression and activated p53 expression in HeLa cells. Finally, the immunofluorescence results indicated that CDV and DDP inhibited the nuclear export of p53 by E6 protein, which is required for degradation of endogenous p53 by MDM2 and human papilloma virus E6. In conclusion, CDV and DDP inhibited HeLa cell proliferation in a concentration- and time-dependent manner, reduced the expression of E6 protein, and reinstated p53 protein activity. Thus, CDV regulates cell cycle arrest and apoptosis, and may be a potential cervical cancer therapeutic strategy.

ISG15 inhibits cancer cell growth and promotes apoptosis

“…Activated-p53 in turn induces cell cycle arrest and/or apoptosis. IFN-treated cells are more susceptible to p53-dependent apoptosis and HeLa cells undergo apoptosis in response to DNA damage in a p53-dependent manner (39,40). We explored the expression of p53 and its downstream protein p21 in HeLa cells treated with IFN-α or in cells overexpressing ISG15.…”

Oncogenic and Stemness Signatures of the High-Risk HCMV Strains in Breast Cancer Progression

“…A study revealed the potential of combining GCV with certain chemotherapeutic agents to suppress EBV-positive NPC tumor growth [ 54 ]. In HPV-infected cervical cancer cells, cidofovir and cisplatin inhibited cellular proliferation, reduced E6 protein expression, and restored the activity of p53 [ 55 ]. A third study showed the effectiveness of anti-herpetic drugs, GCV and cidofovir, as single therapies or in combination with chemotherapy in treating KSHV-associated primary effusion lymphoma (PEL) [ 56 ].…”

The Role of the p16 and p53 Tumor Suppressor Proteins and Viral HPV16 E6 and E7 Oncoproteins in the Assessment of Survival in Patients with Head and Neck Cancers Associated with Human Papillomavirus Infections

“…Briefly, after the standard preparation process, the sections were incubated overnight with the primary antibodies at 4 • C. We used a monoclonal mouse anti-CDKN2A/p16INK4a antibody (Abcam, Cambridge, UK, 1:300 dilution, ab201980); a monoclonal mouse anti-p53 antibody (Santa Cruz Biotechnology, Inc., Dallas, TX, USA, 1:50 dilution, sc-47698); a monoclonal mouse anti-HPV16 E6 + HPV18 E6 antibody (Abcam, Cambridge, UK, prediluted, ab51931) [32][33][34]; and a monoclonal mouse anti-HPV16 E7 antibody (Santa Cruz Biotechnology, Inc., 1:50 dilution, sc-6981). We used a HiDef Detection HRP Polymer system and a diaminobenzidine tetrahydrochloride substrate kit (Cell Marque, Rocklin, CA, USA) to visualize the products of IHC reactions.…”