Genomic aberrations of human papillomavirus recovered from cervical cancers

Human papillomaviruses (HPV) contribute to the development of malignancies of the uterine cervix and the viral E6 and E7 oncogenes are invariably retained and expressed in cervical cancer tissues. Minor, but not major, structural aberrations have been found quite frequently in viral DNA recovered from cervical cancer tissues. We examined the presence of the DNA sequence of HPV type 18 in 33 cervical cancer tissues by polymerase chain reaction. HPV type 18 DNA sequences was found in 24 of these 33 cervical cancer tissue specimens, and at least 21 of these 24 specimens did not appear to retain all the region and open reading frames examined. Twelve of these 24 tissues seemed to harbor only the E6 and/or E7 genes. These results can be construed to suggest that the absence of viral genes other than E6 and E7 is quite frequent in HPV recovered from cervical cancer tissues and that the E6 and E7 genes are important in the carcinogenesis of cervical carcinoma. It is possible that the E6 and/or E7 alone may be sufficient to maintain the transformed phenotype of cervical cancer.