Genetic and epigenetic characteristics of non-muscle invasive and muscle invasive bladder cancer in patients infected by human papillomavirus: literature review

Abstract

Infectious diseases and chronic inflammation are important risk factors for the development of malignant tumors in humans. One of the key infectious agents involved in human oncogenesis is the human papillomavirus (HPV). Non-muscle invasive bladder cancer is defined as a superficial neoplasia limited to the mucosa, aggravated by recurrence in 80 % of cases and progression in 30 % of cases. The development of this disease is associated with the influence of various carcinogenic agents, including HPV. Currently, a direct relationship has been revealed between the presence of viral DNA in the tumor tissue of the bladder and markers of proliferative activity, angiogenesis, and apoptosis factors. More and more researchers believe in the involvement of the virus in the development of recurrent forms of bladder cancer and the emergence of its invasive/poorly differentiated forms. Improving the diagnosis and postoperative monitoring of non-muscle invasive and muscle invasive bladder cancer is not possible without the improvement of minimally invasive molecular methods, which requires an understanding of the molecular mechanisms of HPV-associated carcinogenesis.Therefore, this review focuses on the analysis of the molecular mechanisms of HPV effect on progression of non-muscle invasive and muscle invasive bladder cancer. The features of miRNA expression in patients with papillomavirus infection of high oncogenic risk types and non-muscle invasive or muscle invasive bladder cancer are considered in detail. In particular, the role of miR-34а, -218, -20a, -424, -200a, -205-5p, -944, -100, -99a, -202, -30a, -145-5p, -195 and -199a-5 is described in the development and progression of bladder cancer. The mechanisms of disruption in the functioning of key cell signaling pathways during HPV integration in patients with bladder cancer, including changes in gene copy number and methylation level, are also considered.However, the number of HPV-positive tumor specimens that have been comprehensively analyzed using genome-wide studies in the literature remains small. Larger patient cohorts would be useful to further refine HPV-associated integration events and genomic changes, as well as to study clinical manifestations of the consequences of these alterations. Further research on the clinical implications of the observed genomic changes is needed to accurately stratify patients for targeted therapy, radiation and chemotherapy.