Expression of a novel lacrimal gland gene lacritin in human breast tissues

Abstract

The purpose of this study was to examine breast tumors and normal breast tissues for the expression of the glycoprotein lacritin. The mRNA and protein expression of lacritin has been reported to be restricted to the lacrimal gland. We investigated 37 human primary invasive breast tumors, seven breast cancer cell lines and 16 normal breast tissues by quantitative real-time PCR for lacritin expression. We detected lacritin transcripts in 51% (19/37) of the primary invasive breast tumors, in 71% (5/7) of the breast cancer cell lines, and also in 56% (9/16) of the normal breast tissues. No lacritin mRNA was detectable in peripheral blood of healthy individuals. Here we show by quantitative real-time PCR that lacritin is expressed in human breast tumors, breast cancer cell lines, and normal breast. The previously reported restricted expression pattern of lacritin is therefore incorrect. Lacritin transcripts were not detected in peripheral blood which makes lacritin a potential candidate as a breast cancer marker gene.