Signal Transducers and Activators of Transcription 3 Pathway Activation in Drug-Resistant Ovarian Cancer
Open Access
- 1 September 2006
- journal article
- Published by American Association for Cancer Research (AACR) in Clinical Cancer Research
- Vol. 12 (17), 5055-5063
- https://doi.org/10.1158/1078-0432.ccr-06-0861
Abstract
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.Keywords
This publication has 37 references indexed in Scilit:
- Persistent Activation of Stat3 Signaling Induces Survivin Gene Expression and Confers Resistance to Apoptosis in Human Breast Cancer CellsClinical Cancer Research, 2006
- Effect of Epidermal Growth Factor Receptor Expression Level on Survival in Patients with Epithelial Ovarian CancerClinical Cancer Research, 2005
- Cyclooxygenase-2-Dependent Activation of Signal Transducer and Activator of Transcription 3 by Interleukin-6 in Non–Small Cell Lung CancerClinical Cancer Research, 2005
- Molecular mechanisms of drug resistanceThe Journal of Pathology, 2005
- Expression of multidrug resistance-1 protein inversely correlates with paclitaxel response and survival in ovarian cancer patients: a study in serial samplesGynecologic Oncology, 2004
- The STATs of cancer — new molecular targets come of ageNature Reviews Cancer, 2004
- Ovarian cancer: strategies for overcoming resistance to chemotherapyNature Reviews Cancer, 2003
- OVEREXPRESSION OF IL-6 BUT NOT IL-8 INCREASES PACLITAXEL RESISTANCE OF U-2OS HUMAN OSTEOSARCOMA CELLSCytokine, 2002
- Interleukin-6 level in serum and ascites as a prognostic factor in patients with epithelial ovarian cancerCancer, 1994
- Longitudinal data analysis using generalized linear modelsBiometrika, 1986