GENOTYPING OF HIGH-RISK HPV IN RENAL CELL CARCINOMA PATIENTS FROM PAKISTAN

Abstract

Human papillomavirus (HPV), an epitheliotropic virus, is one of the most common sexually transmitted diseases (STDs). It accounts for approximately 5.2% of all cancers, with high-risk HPV genotypes established as a risk factor for anogenital and oral cancers. Globally, few studies have investigated the etiological association of HPV with renal cell carcinoma (RCC), with inconclusive results. There is also a lack of research on HPV prevalence in RCC patients from Pakistan. Therefore, this study aims to unveil any etiological link between high-risk HPV genotypes (HPV16 and 18) and RCC within the Pakistani population. After informed consent, 50 samples of RCC including the formalin-fixed-paraffin embedded (FFPE) and fresh biopsies, confirmed by H&E and IHC staining, were collected along with histopathological and clinical data. DNA was extracted and processed for HPV detection using L1 consensus primers GP5+/6+ followed by HPV genotyping using E6-E7 specific primers for HPV16 and HPV18, via conventional PCR. For comparative structural analysis, HPV-positive samples were amplified with MY09/11 primers followed by Sanger sequencing. The resulting DNA sequences were translated into protein sequences using MEGA 11 software. Homology modeling was then performed via trROSETTA and the 3D structure alignment via MOE. 30% (15/50) prevalence of HPV was observed of which HPV16&18 co-infection was seen in 93.3% of the cases, while a single case was positive for HPV16 alone. Histologically, all HPV-positive cases were of clear cell RCC subtype with a higher incidence of low-grade tumors. No association of clinicopathological characteristics was found with HPV-positive RCC patients. Moreover, no significant structural variations were seen in the HPV-L1 proteins of the HPV-positive RCC samples. Although the frequency of HPV was not so high, an association was found to be an important risk factor. HPV is therefore a serious issue in low- and middle-income countries (LMICs), significantly contributing to preventable cancers. The globally available HPV vaccines are an effective preventive option for Pakistan, as indicated by comparative structural analysis. Thus, it is imperative to implement local HPV screening and vaccination programs, to lower the burden of HPV-induced carcinomas.