Volume 270,
Number 41,
Issue of October 13, 1995 pp. 24321-24326
©1995 by The American Society for Biochemistry and Molecular Biology, Inc.
Deletion
in Human Chromosome Region 12q13
15 by Integration of Human
Papillomavirus DNA in a Cervical Carcinoma Cell Line
(Received for publication, June 21, 1995; and in revised form, August 9,
1995)
Marta I.
Gallego ,
Pedro A.
Lazo
In human cervical carcinomas papillomavirus DNA is frequently
integrated in the cell genome. We have cloned the integration site of
human papillomavirus-18 DNA in human chromosome region 12q13-15
present in the SW756 cervical carcinoma cell line. Viral DNA is broken
from nucleotides 2643 to 3418 in the E1 and E2 open reading frames,
resulting in a deletion of 775 bases of viral DNA. Cloning and sequence
analysis of the rearranged and germline alleles shows that there is no
homology between the target cellular and viral DNA, suggesting it is a
nonhomologous recombination. The target cellular region is called
papillomavirus associated locus 2 (PAL2). The 5`- and
3`-flanking probes derived from the hybrid viral-cellular clone detect
completely different germline restriction fragments in DNA from cells
with normal chromosome 12. There is no overlap between the restriction
maps of the target germline clones obtained with 5`- and 3`-flanking
probes. Probes from these germline clones beyond the breakpoint
position do not detect any DNA rearrangement in SW756 cells DNA. These
data prove that there is a deletion of cellular DNA as consequence of
the integration, with an estimated minimum size of 14 kilobases. Both
cellular flanking probes are outside the amplicon of this chromosome
region identified in the OSA and RMS13 sarcoma cell lines, comprising SAS-CHOP-CDK4-MDM2 genes and where translocation breakpoints
are located in liposarcomas. The integration at 12q13-15 might
have been selected by its contribution to the tumor phenotype.