IDENTIFICATION OF THE CHROMOSOME-12 TRANSLOCATION BREAKPOINT REGION OF A PLEOMORPHIC SALIVARY-GLAND ADENOMA WITH T(1-12)(P22-Q15) AS THE SOLE CYTOGENETIC ABNORMALITY
Pfj. Kools et al., IDENTIFICATION OF THE CHROMOSOME-12 TRANSLOCATION BREAKPOINT REGION OF A PLEOMORPHIC SALIVARY-GLAND ADENOMA WITH T(1-12)(P22-Q15) AS THE SOLE CYTOGENETIC ABNORMALITY, Cancer genetics and cytogenetics, 79(1), 1995, pp. 1-7
Cell line Ad-312/SV40, which was derived from a primary pleomorphic sa
livary gland adenoma with t(1;12)(p22;q15), was used in fluorescence i
n situ hybridization (FISH) analysis to characterize its translocation
breakpoint region on chromosome 12. Results of previous studies have
indicated that the chromosome 12 breakpoint in Ad-312/SV40 is located
proximally to locus D12S8 and distally to the CHOP gene. We here descr
ibe two partially overlapping yeast artificial chromosome (YAC) clones
, Y4854 (500 kbp) and Y9091 (460 kbp), which we isolated in the contex
t of a chromosome walking project with D12S8 and CHOP as starting poin
ts. We present a composite long-range restriction map encompassing the
inserts of these two YAC clones and show by FISH analysis that both Y
ACs span the chromosome 12 breakpoint os present in Ad-312/SV40 cells.
Subsequently, we have isolated cosmid clones corresponding to various
sequence-tagged sites (STSs) mapping within the inserts of these YAC
clones. These included cRM51, cRM69, cRM85, cRM90, cRM91, cRM110 and c
RM111. In FISH studies, cosmid clones cRM85, cRM90, and cRM111 appeare
d to map distally to the chromosome 12 breakpoint, whereas cosmid clon
es cRM51, cRM69, cRM91, and cRM110 were found to map proximally to it.
These results assign the chromosome 12 breakpoint in Ad-312/SV40 to a
DNA region of less than 165 kbp. FISH evaluation of the chromosome 12
breakpoints in five other pleomorphic salivary gland adenoma cell lin
es indicated that these are located proximally to the one in Ad-312/SV
40, at a distance of more than 0.9 Mbp from STS RM91. These results, w
hile pinpointing a potentially critical region on chromosome 12, also
provide evidence for the possible involvement of 12q13-q15 sequences l
ocated elsewhere.