HPV genotyping and p16 expression in Xingu Indigenous Park, Brazil

• Published in: Genetics and molecular research 2016-09, Vol.15 (3)
• Main Authors: Freitas, V G, Focchi, G R, Pereira, E R, Levi, J E, Speck, N M G, Ribalta, J C
• Format: Article
• Language: English
• Subjects: Adult; Aged; Biomarkers, Tumor - biosynthesis; Biomarkers, Tumor - genetics; Brazil; Cervical Intraepithelial Neoplasia - genetics; Cervical Intraepithelial Neoplasia - pathology; Cervical Intraepithelial Neoplasia - virology; Colposcopy; Cyclin-Dependent Kinase Inhibitor p16 - biosynthesis; Cyclin-Dependent Kinase Inhibitor p16 - genetics; Female; Gene Expression Regulation; Genotype; Human papillomavirus 16 - genetics; Human papillomavirus 16 - isolation & purification; Human papillomavirus 16 - pathogenicity; Human papillomavirus 31 - genetics; Human papillomavirus 31 - isolation & purification; Human papillomavirus 31 - pathogenicity; Humans; Middle Aged; Papillomavirus Infections - genetics; Papillomavirus Infections - pathology; Papillomavirus Infections - virology
• ISSN: 1676-5680; 1676-5680
• DOI: 10.4238/gmr.15036840

The association between high-risk human papillomavirus (HPV) genotypes and p16 expression in indigenous women from the Xingu Indigenous Park, Brazil, was unknown. This study evaluated p16 expression in women with a histological diagnosis of cervical intraepithelial neoplasia (CIN) 3 or higher and correlated this expression with HPV genotypes to determine possible discrepancies in the expression of this marker. We evaluated 37 previously collected samples with different HPV genotypes and high-grade lesions diagnosed based on cytology, histology, and colposcopy. Immunohistochemical analysis was performed using paraffin-embedded tissue sections and the CINtec® Histology Kit. p16 protein expression was investigated by immunostaining with an anti-p16 antibody. HPV genotyping was performed by reverse hybridization. The age of the study population ranged from 22-75 years (43.81 ± 15.89 years) and parity ranged from 1-11 (5.92 ± 2.58). Thirteen different HPV genotypes were found using the INNO-LiPA kit. Single and multiple infections by HPV were found with prevalence of single infections (P = 0.029). Comparison between HPV genotype and simple or multiple infections was highly significant; it was observed more HPV 52 followed by HPV 16 in single infections (P < 0.001). p16 expression was predominantly diffuse, which was observed in 91.7% of lesions, whereas 8.3% were focal (P < 0.001). HPV 52, HPV 16 and 31 were the most prevalent HPV types in high-grade CIN in these indigenous women. Diffuse p16 expression in high-grade CIN was not influenced by the viral genotype; however, more studies are necessary to further our understanding of this restricted group.