Pro-inflammatory cytokines analysis in HPV-positive cancer cells

Recent data have expanded the concept that inflammation is a critical component of tumor progression. Many cancers arise from sites of infection, chronic irritation and inflammation. It is becoming clear that the tumor microenvironment is an indispensable participant in the neoplastic process, fostering proliferation, survival and migration. In addition, tumor cells have co-opted some of the signalling molecules of the innate immune system, such as selectins, chemokines and their receptors for invasion, migration and metastasis. Virus-induced tumors, like cervical high risk Papillomavirus-induced Squamous Cell Carcinomas (SCC), represent a paradigmatic example of the tight interplay between inflammatory responses and malignant transformation as inflammation is an integral part of the innate antiviral response. To establish a tumorigenic role of inflammatory mediators in HPV+ SCC, we analysed by real time RT-PCR the expression of inflammatory cytokines, chemokines and related molecules (i.e. IL-1α, IL-1β, IL-1RA, IL-1R1, IL-6, IL-8, MIP-1α and MIP-1β) in several HPV+ carcinoma cell lines as well as in HPV- SCC (i.e. C33A). We also analysed human foreskin keratinocytes transduced by E6 and E7 from mucosal (HPV-16) or cutaneous (HPV-38) genotypes. Our results indicate that in HPV+ SCC the level of IL-1β mRNA is augmented compared to HPV- SCC. Interestingly, despite huge increase in mRNA levels, these cells didn’t secrete any IL-1β. On the other hand, IL-6 mRNA appears upregulated in the same cells as well as secreted in the supernatants. Finally, we also tested the effect of the antiviral cytokine IFN-β on the levels of these pro-inflammatory mediators.