Chromosome 7q allelic losses in pancreatic carcinoma

During our DNA fingerprinting studies of paired normal and pancreatic cancer tissues using arbitrarily primed PCR, we noticed a band showing an apparent homozygous deletion in a pancreatic cancer cell line and a decreased intensity in a number of primary cancers. That band was assigned to chromosome 7. Such information led us to analyze chromosome 7 loss of heterozygosity (LOH) in a panel of 12 cryostat-enriched primary pancreatic cancers and 2 pancreatic cancer cell lines, despite the reportedly low frequency of chromosome 7 LOH in xenograft-enriched pancreatic cancers. Seventeen PCR-amplified CA-microsatellite polymorphic sites were analyzed. One of the two cell lines and eight common-type cancers (including all five poorly differentiated and three of five moderately differentiated cancers) showed chromosome 7q LOH, whereas the two uncommon types of ductal cancer (one adenosquamous and one mucinous noncystic) scored negative. Our data suggest that chromosome 7q LOH is a frequent event (80%) in cryostat-enrichable common pancreatic ductal carcinomas, that is, those primarily of high cellularity. The chromosome 7q smallest common deleted region described by our cases was between 7q31.1 and 7q32.