Characterization of copine VII, a new member of the copine family, and itsexclusion as a candidate in sporadic breast cancers with loss of heterozygosity at 16q24.3

In a search for candidate tumor suppressor genes within a 650-kb common reg ion of loss of heterozygosity (LOH) at 16q24.3 in breast cancer tissues, a 2.6-kb cDNA, named copine VII (CPNE7), was characterized. The gene is 2654 bp and codes for a 633-residue protein with high homology to the other memb ers of the copine family, such as copine I, copine III, and N-copine. The p redicted amino acid sequence contains two copies of a C2 domain in the N-te rminus. Since these domains have been found in several membrane-binding pro teins involved in different intracellular processes, copine VII was viewed as a potential tumor suppressor gene. Mutation analysis was carried out by single-strand conformation polymorphism analysis of 18 breast tumor tissue samples with ascertained LOH on chromosome 16q24.3, Since only two polymorp hisms were identified, no evidence was found to indicate that copine VII is the tumor suppressor gene at 16q24.3 involved in breast cancer. (C) 1999 A cademic Press.