Identification of rearranged sequences of HPV16 DNA in precancerous and cervical cancer cases.

Integration of HPV16 DNA into the host chromosome is considered to be a crucial step towards genomic instability and cervical cancer development. Aim of the present study was to investigate the presence of HPV16 rearranged intra-viral sequences in HPV16-positive normal, precancerous and cervical cancer samples using the method of Restriction Site-PCR (RS-PCR). Sequence analysis of HPV16 integrants revealed for the first time in clinical samples two distinct rearranged intra-viral sequences, concerning the conjunction of E2 and L1 genes and the conjunction of E1 and L1 genes with inverted orientation. Furthermore mapping analysis of the E1 and E2 genes in cervical samples with rearranged intra-viral sequences of HPV16 genome was conducted in order to determine the integrity of viral genes. The identification of intra-viral rearrangements provides valuable information regarding the HPV16 DNA integration, and may be a significant biomarker for the presence of chromosomal instability and DNA damages in clinical samples.