Several benign and malignant skin
tumors were analyzed for the presence of human papillomavirus (HPV)
DNA. By hybridization with different
HPV DNA probes under non-stringent conditions (Tm -40 degrees C), two
tumors were found to contain HPV-specific DNA sequences in high copy numbers: (1) a
keratoacanthoma from a patient who also suffered from a basalioma; (2) a superficial spreading
malignant melanoma of an immunosuppressed patient. For further analysis of these DNA sequences genomic libraries from both
tumor DNAs were constructed and, out of these, 4 different HPV
DNA types have been cloned. By cross-hybridization experiments and restriction map analysis HPV 9
DNA was identified in the
keratoacanthoma whereas HPV 17a
DNA could be cloned from the
malignant melanoma. From each
tumor one additional HPV-type not identical to other known HPV-types was cloned. These isolates are closely related to HPV 9, 15, 17, 22 and 23. A physical map of both HPV DNAs was constructed. Size (7.8 kbp), co-linear alignment to HPV 16, cross-hybridization with other HPV-types under conditions of low stringency and monomeric episomal state of the HPV molecules indicate that these two
DNA probes represent new HPV types that have been tentatively designated as HPV 37 (
keratoacanthoma) and HPV 38 (
malignant melanoma). None of these two HPV types could be found in any other of 231
tumor DNAs originating from different tissues.