Characterization of Desmoglein 2 Expression in Ovarian Serous Tumors and Its Prognostic Significance in High-Grade Serous Carcinoma

: Desmogleins (Dsgs) are major members of the desmosomal cadherins that are critically involved in cell-cell adhesion and the maintenance of normal tissue architecture in epithelia. DSG2 is the most ubiquitous desmosomal cadherin; however, abnormal expression of DSG2 has been detected in several types of cancer with controversial results. So far, little is known about DSG2 expression in ovarian serous tumor (OST) and its associations with survival and clinicopathologic data. In this study, mRNA and protein expression of DSG2 was detected in 33 cases of nonfixed samples and 92 cases of paraffin-embedded OST specimens (including benign, borderline, low-grade, and high-grade) by using qRT-PCR and immunohistochemistry, respectively. DSG2 expression was then measured in 162 cases of high-grade serous carcinoma (HGSC) by immunohistochemistry, and the expression levels were correlated with clinicopathologic and prognostic data. As the results, DSG2 could be readily detected in benign tumor with relative weak expression at the mRNA level and showed weak but complete staining at the cell-cell borders. This was similar to the expression pattern in the normal fallopian epithelial tissue. However, the expression tendency of DSG2 at the mRNA and protein level was inconsistent in borderline and malignant OST. In addition, we found that a low DSG2 expression was associated with poor prognosis (P < 0.05) and high mitosis (P = 0.0042) of HGSC. Thus, DSG2 may be involved in the progression of ovarian cancer and plays a different role in different OST. Moreover, a low DSG2 expression was associated with poor prognosis of HGSC.