Mucin gene expression in ovarian cancers

Ovarian cancer is a highly lethal disease with metastases present in the ma jority of patients at the time of diagnosis. The molecular mechanisms under lying the metastatic process of this cancer are not well understood. One fa mily of cell-associated and secreted glycoproteins, the mucin glycoproteins , has been implicated in events leading to metastasis of several epithelial cancers including gastrointestinal and lung cancers. The purpose of this s tudy was to characterize mucin gene expression in ovarian cancers and relat e expression to tumor histology, stage, and patient survival. RNA nas isola ted from 29 epithelial ovarian cancers, 1 neuroendocrine carcinoma, 3 mixed mesodermal tumors, and two transformed, yet nonmalignant, ovarian epitheli al cell lines. The expression of mucin genes, MUC1, 2, 3, 4, 5AC and 5B, wa s determined by northern analyses. Epithelial ovarian cancers expressed sev eral mucins including MUC1, 2, 4, and 5AC; MUC3 and 5B were rarely expresse d. In contrast, the transformed nonmalignant ovarian epithelial cell lines expressed only MUC1 and 5AC. Although there was no correlation of mucin exp ression with tumor histology, there was a significant decrease in expressio n of MUC3 and MUC4 with increasing cancer stage (P < 0.05). In addition, a trend toward improved patient survival occurred with increased expression o f MUC4. These observations suggest a relationship between mucin gene expres sion and the metastatic process in epithelial ovarian cancers. Additional i nvestigation of MUC3 and MUC4 in ovarian cancers may lead to new approaches for early detection and therapy.