KAI1, A METASTASIS SUPPRESSOR GENE FOR PROSTATE-CANCER ON HUMAN-CHROMOSOME 11P11.2

A gene from human chromosome 11p11.2 was isolated and was shown to sup press metastasis when introduced into rat AT6.1 prostate cancer cells. Expression of this gene, designated KAI1, was reduced in human cell l ines derived from metastatic prostate tumors. KAI1 specifies a protein of 267 amino acids, with four hydrophobic and presumably transmembran e domains and one large extracellular hydrophilic domain with three po tential N-glycosylation sites. KAI1 is evolutionarily conserved, is ex pressed in many human tissues, and encodes a member of a structurally distinct family of leukocyte surface glycoproteins. Decreased expressi on of this gene may be involved in the malignant progression of prosta te and other cancers.