Molecular analysis of cellular loci disrupted by papillomavirus 16 integration in cervical cancer: frequent viral integration in topologically destabilized and transcriptionally active chromosomal regions.
To discern the structural features of cellular loci that are disrupted by type 16 human papillomavirus (HPV-16) integration in cervical cancer, a polymerase chain reaction (PCR)-based strategy was employed for direct amplification and sequence analysis of four such cellular loci in cancer biopsy samples. One of the HPV-16-disrupted loci was found to be the microtubule-associated protein (MAP-2) gene and the other three loci were uncharacterized and were designated PID-1 to -3 (for papillomavirus integration-disrupted). The junctional sequences of the viral integration sites in the four loci analyzed are bracketed by long tracts of homogeneous purine or pyrimidine or alternating purine-pyrimidine which are known to destabilize the B-form conformation of the DNA structure. Using a panel of human/hamster hybrid cell DNAs and PCR analysis, the four loci were assigned to chromosomes 2 (MAP-2), 9 (PID-1), 1 (PID-2) and 8 (PID-3), respectively. These chromosomes carry numerous other previously determined viral integration and chromosomal fragile sites and the myc oncogenes. The PID-1 locus was further found in Southern analysis to be rearranged and amplified in another cervical cancer biopsy and a cervical carcinoma cell line (CaSki). On Northern analysis, the PID-1 and -3 probes detected a 3.0- and a 3.6-kb transcript, respectively, in normal cervical cells and in cervical cancer cell lines. The findings suggest that HPV-16 genome integrates frequently into topologically destabilized and transcriptionally active chromosomal sites. It remains to be elucidated whether the MAP-2 and the PID loci contribute to the pathogenesis of cervical cancer.
Choo
K B
KB
Department of Medical Research and Education, Veterans General Hospital, Taipei, Taiwan, Republic of China.
Chen
C M
CM
Han
C P
CP
Cheng
W T
WT
Au
L C
LC
D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002874:Chromosome Mapping; D004279:DNA, Viral; D005260:Female; D006801:Humans; D008969:Molecular Sequence Data; D027383:Papillomaviridae / Q000235:genetics* / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000473:pathology / Q000821:virology*; D014407:Tumor Cells, Cultured; D014412:Tumor Virus Infections / Q000473:pathology / Q000821:virology*; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000821:virology*; D016662:Virus Integration
D004279:DNA, Viral