Journal Article

Curcumin and Emodin Down-Regulate TGF-β Signaling Pathway in Human Cervical Cancer Cells

Karunagaran, Devarajan, Thacker, Pooja Chandrakant

2015

Overview

Cervical cancer is the major cause of cancer related deaths in women, especially in developing countries and Human Papilloma Virus infection in conjunction with multiple deregulated signaling pathways leads to cervical carcinogenesis. TGF-β signaling in later stages of cancer is known to induce epithelial to mesenchymal transition promoting tumor growth. Phytochemicals, curcumin and emodin, are effective as chemopreventive and chemotherapeutic compounds against several cancers including cervical cancer. The main objective of this work was to study the effect of curcumin and emodin on TGF-β signaling pathway and its functional relevance to growth, migration and invasion in two cervical cancer cell lines, SiHa and HeLa. Since TGF-β and Wnt/β-catenin signaling pathways are known to cross talk having common downstream targets, we analyzed the effect of TGF-β on β-catenin (an important player in Wnt/β-catenin signaling) and also studied whether curcumin and emodin modulate them. We observed that curcumin and emodin effectively down regulate TGF-β signaling pathway by decreasing the expression of TGF-β Receptor II, P-Smad3 and Smad4, and also counterbalance the tumorigenic effects of TGF-β by inhibiting the TGF-β-induced migration and invasion. Expression of downstream effectors of TGF-β signaling pathway, cyclinD1, p21 and Pin1, was inhibited along with the down regulation of key mesenchymal markers (Snail and Slug) upon curcumin and emodin treatment. Curcumin and emodin were also found to synergistically inhibit cell population and migration in SiHa and HeLa cells. Moreover, we found that TGF-β activates Wnt/β-catenin signaling pathway in HeLa cells, and curcumin and emodin down regulate the pathway by inhibiting β-catenin. Taken together our data provide a mechanistic basis for the use of curcumin and emodin in the treatment of cervical cancer.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Antineoplastic Agents, Phytogenic - pharmacology / Apoptosis / beta Catenin - antagonists & inhibitors / beta Catenin - genetics / beta Catenin - metabolism / Biochemistry / Biotechnology / Breast cancer / Cancer / Cancer therapies / Carcinogenesis / Carcinogens / Cell adhesion & migration / Cell cycle / Cell Line, Tumor / Cell migration / Cell Movement - drug effects / Cell Proliferation - drug effects / Cervical cancer / Cervix / Chemotherapy / Collagen - chemistry / Crosstalk / Curcumin / Curcumin - pharmacology / Cyclin D1 - antagonists & inhibitors / Cyclin D1 - genetics / Cyclin D1 - metabolism / Cyclin-Dependent Kinase Inhibitor p21 - antagonists & inhibitors / Cyclin-Dependent Kinase Inhibitor p21 - genetics / Cyclin-Dependent Kinase Inhibitor p21 - metabolism / Deregulation / Developing countries / Downstream / Drug Combinations / Drug Synergism / Emodin / Emodin - pharmacology / Epithelial-Mesenchymal Transition - drug effects / Female / Gene expression / Gene Expression Regulation, Neoplastic / HeLa Cells / Human papillomavirus / Humans / Kinases / Laminin - chemistry / LDCs / Ligands / Medical research / Mesenchyme / Metastasis / NIMA-Interacting Peptidylprolyl Isomerase / Peptidylprolyl Isomerase - genetics / Peptidylprolyl Isomerase - metabolism / Phytochemicals / Pin1 protein / Protein-Serine-Threonine Kinases - antagonists & inhibitors / Protein-Serine-Threonine Kinases - genetics / Protein-Serine-Threonine Kinases - metabolism / Proteins / Proteoglycans - chemistry / Receptors, Transforming Growth Factor beta - antagonists & inhibitors / Receptors, Transforming Growth Factor beta - genetics / Receptors, Transforming Growth Factor beta - metabolism / Signal transduction / Signal Transduction - drug effects / Signaling / Smad3 protein / Smad3 Protein - antagonists & inhibitors / Smad3 Protein - genetics / Smad3 Protein - metabolism / Smad4 protein / Smad4 Protein - antagonists & inhibitors / Smad4 Protein - genetics / Smad4 Protein - metabolism / Snail Family Transcription Factors / Transcription Factors - antagonists & inhibitors / Transcription Factors - genetics / Transcription Factors - metabolism / Transforming Growth Factor beta - antagonists & inhibitors / Transforming Growth Factor beta - genetics / Transforming Growth Factor beta - metabolism / Tumor cell lines / Tumorigenesis / Viruses / Wnt protein / Wnt Proteins - genetics / Wnt Proteins - metabolism / β-Catenin