Leucine Zipper, Putative Tumor Suppressor 1 (LZTS1)

LZTS1 encodes a tumor suppressor protein that is ubiquitously expressed in normal tissues. In uveal melanomas, expression of this protein is silenced in rapidly metastasizing and metastatic tumor cells but has normal expression in slowly metastasizing or nonmetastasizing tumor cells. This protein may have a role in cell-cycle control by interacting with the Cdk1/cyclinB1 complex. This gene is located on chromosomal region 8p22. Loss of heterozygosity (LOH) in the 8p arm is a common characteristic of many types of cancer. FEZ1 expression was undetectable in more than 60% of epithelial tumors, but FEZ1 mutations were found in primary esophageal cancers and in a prostate cancer cell line. Transcript analysis from several FEZ1-expressing tumors revealed truncated mRNAs, including a frameshift.