ABSTRACT
Cadherin-11 (CDH11), associated with epithelial to mesenchymal transformation in development, poor prognosis malignancies and cancer stem cells, is also a major therapeutic target in rheumatoid arthritis (RA). CDH11 expressing basal-like breast carcinomas and other CDH11 expressing malignancies exhibit poor prognosis. We show that CDH11 is increased early in breast cancer and ductal carcinoma in-situ. CDH11 knockdown and antibodies effective in RA slowed the growth of basal-like breast tumors and decreased proliferation and colony formation of breast, glioblastoma and prostate cancer cells. The repurposed arthritis drug celecoxib, which binds to CDH11, and other small molecules designed to bind CDH11 without inhibiting COX-2 preferentially affect the growth of CDH11 positive cancer cells in vitro and in animals. These data suggest that CDH11 is important for malignant progression, and is a therapeutic target in arthritis and cancer with the potential for rapid clinical translation.
Subject(s)
Arthritis, Rheumatoid/metabolism , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Cadherins/metabolism , Carcinoma, Ductal, Breast/metabolism , Pyrazoles/pharmacology , Sulfonamides/pharmacology , Animals , Antibodies, Monoclonal/pharmacology , Apoptosis/drug effects , Arthritis, Rheumatoid/drug therapy , Arthritis, Rheumatoid/pathology , Blotting, Western , Breast Neoplasms/pathology , Cadherins/antagonists & inhibitors , Cadherins/genetics , Carcinoma, Basal Cell/drug therapy , Carcinoma, Basal Cell/metabolism , Carcinoma, Basal Cell/pathology , Carcinoma, Ductal, Breast/drug therapy , Carcinoma, Ductal, Breast/pathology , Carcinoma, Intraductal, Noninfiltrating/drug therapy , Carcinoma, Intraductal, Noninfiltrating/metabolism , Carcinoma, Intraductal, Noninfiltrating/pathology , Carcinoma, Lobular/drug therapy , Carcinoma, Lobular/metabolism , Carcinoma, Lobular/pathology , Celecoxib , Cell Movement/drug effects , Cell Proliferation/drug effects , Cyclooxygenase 2 Inhibitors/pharmacology , Female , Flow Cytometry , Humans , Immunoenzyme Techniques , Mice , Mice, Nude , RNA, Messenger/genetics , RNA, Small Interfering/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Surface Plasmon Resonance , Tumor Cells, Cultured , Tumor Stem Cell Assay , Xenograft Model Antitumor AssaysABSTRACT
PURPOSE: One of the major obstacles in the treatment of ovarian cancer is the development of multidrug resistance. Recent evidence shows that high-grade ovarian cancer often shows activation of the signal transducers and activators of transcription 3 (Stat3) pathway with subsequent transcription of genes that support tumor growth and survival. Less studied is the role of the Stat3 pathway in acquired drug resistance. There is no information on Stat3 expression in chemotherapy naïve ovarian cancer as compared with tumors collected later in the natural history of the disease. To further clarify the significance of Stat3 activation in ovarian cancer, here we investigated the Stat3 expression and activation in ovarian cancer and ovarian cancer multidrug resistance cell lines. EXPERIMENTAL DESIGN: Western blotting, electrophoretic mobility shift assay, luciferase assays, ELISA assay, and real-time reverse transcription-PCR determined interleukin-6 and Stat3 pathway expression and activation in cell lines. Stat3 expression in ovarian cancer tissue microarray was evaluated by immunohistochemistry. RESULTS: Activated (phosphorylated) Stat3 is overexpressed in most paclitaxel-resistant ovarian cancer cells. Inhibition of Stat3 activation results in significant decreases in paclitaxel resistance and enhanced apoptosis. Drug-resistant recurrent tumors have significantly greater phosphorylated Stat3 (pStat3) expression as compared with matched primary tumors. Tumors with associated inflammatory cell infiltrates also have a higher proportion of cells staining intensely for nuclear phosphorylated Stat3 as compared with tumors without inflammatory infiltrates, consistent with paracrine activation of the Stat3 pathway by immune-mediated cytokines. CONCLUSIONS: These data support the hypothesis that interruption of Stat3 signaling could reverse resistance to paclitaxel and perhaps other chemotherapy agents in human cancer.
