Cloning of BRAK, a novel divergent CXC chemokine preferentially expressed in normal versus malignant cells

Chemokines are a family of related proteins that regulate leukocyte infiltr ation into inflamed tissue and play important roles in many disease process es. Chemokines are divided into two major groups, CC or CXC, based on their sequence around the amino terminal cysteines. We report the PCR cloning of a novel human chemokine termed BRAK for its initial isolation from breast and kidney cells. This novel chemokine is distantly related to other CXC ch emokines (30% identity with MIP-2 alpha and beta) and shares several biolog ical activities. BRAK is expressed ubiquitously and highly in normal tissue . However, it was expressed in only 2 of 18 cancer cell lines. BRAK is loca ted on human chromosome 5q31. (C) 1999 Academic Press.