MOLECULAR-CLONING AND CHARACTERIZATION OF LOH11CR2A, A NEW GENE WITHIN A REFINED MINIMAL REGION OF LOH AT 11Q23

Deletions at chromosome 11q23 are frequent events in a variety of huma n neoplasms, including breast, lung, and ovarian carcinomas. Two commo n regions of loss of heterozygosity, shared between lung and breast ca rcinomas, have been previously identified at 11q23, suggesting that th e same tumor susceptibility genes are altered in these two malignancie s. One of these regions, refined in lung adenocarcinoma, is included b etween loci D11S1345 and D11S1328. Here, we describe the refinement of the same region in breast carcinomas and the characterization of a ne w gene found within this area. The gene, called LOH11CR2A, spans an ar ea of approximately 40 kb and is transcribed at a low level in all the tissues in which it has been analyzed. The predicted amino acid prima ry sequence revealed no homology with other proteins that could help t o elucidate a possible function for the LOH11CR2A protein. Here, we te sted the hypothesis that LOH11CR2A could be a tumor suppressor gene. A nalysis of human breast, lung, and ovarian carcinomas revealed the pre sence of several amino acid substitutions in the coding region of this gene. However, a role for these amino acid changes in the tumorigenic process could not established. (C) 1997 Academic Press.