Genetic alterations in gallbladder carcinoma.

Gallbladder carcinoma is an aggressive cancer associated with a poor prognosis. Unfortunately, the precise molecular mechanisms of development and progression of this highly malignant tumor remain unknown. It is still unclear whether loss of heterozygosity (LOH) plays a significant role in gallbladder carcinogenesis, but recent studies have found a high incidence of LOH at several chromosomes in gallbladder carcinoma. In particular, LOH on chromosomes 1p, 3p, 5p, 8p, 9p, 9q, 13q, 16q, and 17p has been highlighted and LOH on 3p, 9p, 13q, 16q, and 17p has been detected in preneoplastic lesions and in the early phase of gallbladder carcinoma during multistep carcinogenesis. The proto-oncogene, K-ras, is the best known genetic alteration in several human neoplasms, including gallbladder carcinoma. The accumulation of these genetic changes leads to a disruption in cell-cycle regulation and also continuous cell proliferation. We present an overview of K-ras alteration and LOH at several chromosome loci in gallbladder carcinoma. Further studies of the molecular mechanism in gallbladder carcinoma and the delineation of the genetic influence involved should promote our understanding of gallbladder carcinogenesis.