Study of genetic variability of human papillomavirus and determination of molecular targets for detection and typing
Human papillomavirus, cervical cancer, PCR, genotyping, selective pressure, diversity
Human papillomavirus (HPV) is a small DNA virus characterized as one of the most common sexually transmitted agents worldwide, whose accurate detection and genotyping is only possible through molecular biology techniques. Among the more than 180 different types already characterized, different evolutionary dynamics and biological properties have been reported, so that a particular group of HPVs is strongly related to chronic infections and progression to cancers such as cervical, anal, vulvar, vaginal, oropharyngeal and of penis. In the present work, analyzes of genomic variability, selection pressure and phylogeny were performed, revealing divergent profiles between some coding regions of different groups, indicating probable determinants for viral evolution. The characterization of these regions allowed the selection of molecular targets for the development of a new set of primers for the detection and genotyping of HPV through the polymerase chain reaction (PCR) technique. The E1 viral gene was chosen as the target, due to the presence of a conserved region of variable size among the genotypes. The proposed system was validated in vitro, and compared with the gold-standard HPV detection system. The proposed method allowed the discrimination of the main oncogenic HPV types through the analysis of the size of the amplified fragment by agarose/polyacrylamide gel electrophoresis, with confirmation by direct sequencing, reducing the time and cost necessary for viral identification. Understanding the viral diversity and evolution is an important tool for the future development of new diagnostic and therapeutic approaches to this global public health problem.