Increased tissue immunoexpression of YKL-40 protein in high grade serous ovarian cancers

YKL-40 is a glycoprotein secreted by numerous human cells, such as cartilage, synovial, and endothelial cells. The biological role of YKL-40 has not yet been fully unveiled, however, its participation is perceived in angiogenesis, growth, proliferation, differentiation, and remodeling processes. The primary goal of our study was to evaluate possible differences in tissue immunoexpression of YKL-40, assumed between high grade and low-grade ovarian cancers and between the above-mentioned cancer types and benign lesions. Another purpose was to find out whether immunoexpression of the studied protein could correlate with the tumor proliferation process, evaluated by Ki-67 immunoexpression. The analysis comprised 45 women, diagnosed and treated for epithelial ovarian tumors at the Medical University of Lodz between 1997 and 2002. YKL-40 protein immunoexpression was semiquantitatively assessed, whereas immunoexpression of Ki-67 was evaluated using a computer image analysis system. Significantly higher immunoexpression values of both examined proteins were observed in high-grade serous ovarian cancers vs. low-grade and benign tumors. Moreover, a significant positive correlation was identified between the immunoexpressions of YKL-40 and Ki-67 proteins in the studied groups of tumors. In conclusion, the obtained data suggest an overt prominence of TKL-40 tissue immunoexpression of YKL-40 in high-grade serous ovarian tumors, which could then be approached as a helpful, additional marker to identify more aggressive ovarian cancers.