Inhibitory effects of 3,3'-diindolylmethane on epithelial-mesenchymal transition induced by endocrine disrupting chemicals in cellular and xenograft mouse models of breast cancer.

As a phytoestrogen, 3,3'-diindolylmethane (DIM) plays a chemopreventive role by inhibiting cancer progression. In this study, we examined the effects of 17β-estradiol (E2), two endocrine disrupting chemicals (EDCs), triclosan (TCS) and bisphenol A (BPA), and DIM on epithelial-mesenchymal transition (EMT) and metastatic behaviors of estrogen receptor (ER)-positive MCF-7 breast cancer cells. An in vitro assay revealed that E2 (10-9 M), TCS (10-5-10-7 M), and BPA (10-5-10-7 M) induced MCF-7 cell proliferation compared to a control through the ER pathway. In addition, E2, TCS, and BPA changed the cell morphology from the epithelial to the mesenchymal phenotype and increased the migration and invasion capacity of MCF-7 cells via ER; however, co-treatment with DIM (20 μM) effectively suppressed E2, TCS, and BPA-induced cell proliferation, EMT, migration, and invasion of MCF-7 cells. Western blot assay revealed that DIM regulated the protein expression of EMT- and metastasis-related genes toward the inhibition of these processes. Moreover, E2, TCS, and BPA increased the protein expression of CXCR4, which is a receptor of chemokine CXCL12 that is positively involved in breast cancer metastasis via an ER-dependent pathway. Conversely, DIM and a CXCR4 antagonist (AMD3100) decreased CXCR4 protein expression, which led to inhibition of the EMT process, indicating that DIM may suppress E2, TCS or BPA-induced EMT, migration, and invasion of MCF-7 breast cancer cells by suppressing CXCR4 protein expression. These in vitro effects of E2, TCS, BPA, and DIM were also identified in a xenografted mouse model transplanted with MCF-7 breast cancer cells. Taken together, DIM is a potent chemopreventive compound for preventing metastatic behaviors of breast cancer cells induced by EDCs with cancer-related toxicity.

Lee GA ，Hwang KA ，Choi KC 《-》

Progression of breast cancer cells was enhanced by endocrine-disrupting chemicals, triclosan and octylphenol, via an estrogen receptor-dependent signaling pathway in cellular and mouse xenograft models.

Lee HR ，Hwang KA ，Nam KH ，Kim HC ，Choi KC ... -  《-》

Genistein suppressed epithelial-mesenchymal transition and migration efficacies of BG-1 ovarian cancer cells activated by estrogenic chemicals via estrogen receptor pathway and downregulation of TGF-β signaling pathway.

Epithelial-mesenchymal transition (EMT), which is activated by 17β-estradiol (E2) in estrogen-responsive cancers, is an important process in tumor migration or progression. As typical endocrine disrupting chemicals (EDCs), bisphenol A (BPA) and nonylphenol (NP) have a potential to promote EMT and migration of estrogen-responsive cancers. On the contrary, genistein (GEN) as a phytoestrogen is known to have chemopreventive effects in diverse cancers. In the present study, the effects of BPA and GEN on EMT and the migration of BG-1 ovarian cancer cells and the underlying mechanism were investigated. ICI 182,780, an estrogen receptor (ER) antagonist, was co-treated with E2 or BPA or NP to BG-1 cells to identify the relevance of ER signaling in EMT and migration. As results, E2 and BPA upregulated the protein expression of vimentin, cathepsin D, and MMP-2, but downregulated the protein expression of E-cadherin via ER signaling pathway, suggesting that E2 and BPA promote EMT and cell migration related gene expressions. However, the increased protein expressions of vimentin, cathepsin D, and MMP-2 by E2, BPA, or NP were reduced by the co-treatment of GEN. In a scratch assay, the migration capability of BG-1 cells was enhanced by E2, BPA, and NP via ER signaling but reversed by the co-treatment of GEN. In the protein expression of SnoN and Smad3, E2, BPA, and NP upregulated SnoN, a negative regulator of TGF-β signaling, and downregulated pSmad3, a transcription factor in the downstream pathway of TGF-β signaling pathway, suggesting that E2, BPA, and NP simultaneously lead to the downregualtion of TGF-β signaling in the process of induction of EMT and migration of BG-1 cells via ER signaling. On the other hand, the co-treatment of GEN reversed the downregulation of TGF-β signaling by estrogenic chemicals. Taken together, GEN suppressed EMT and migration capacities of BG-1 ovarian cancer cells enhanced by E2, BPA, and NP via ER signaling and the downregulation of TGF-β signal.

Kim YS ，Choi KC ，Hwang KA 《-》

Kaempferol, a phytoestrogen, suppressed triclosan-induced epithelial-mesenchymal transition and metastatic-related behaviors of MCF-7 breast cancer cells.

As a phytoestrogen, kaempferol is known to play a chemopreventive role inhibiting carcinogenesis and cancer progression. In this study, the influences of triclosan, an anti-bacterial agent recently known for an endocrine disrupting chemical (EDC), and kaempferol on breast cancer progression were examined by measuring their effects on epithelial-mesenchymal transition (EMT) and metastatic-related behaviors of MCF-7 breast cancer cells. Morphological changes of MCF-7 cells were observed, and a wound-healing assay was performed after the treatment of triclosan and kaempferol. The effects of triclosan and kaempferol on protein expression of EMT-related markers such as E-cadherin, N-cadherin, Snail, and Slug and metastasis-related markers such as cathepsin B, D, MMP-2 and -9 were investigated by Western blot assay. In microscopic observations, triclosan (10-6M) or E2 (10-9M) induced transition to mesenchymal phenotype of MCF-7 cells compared with the control. Co-treatment of ICI 182,780 (10-8M), an ER antagonist, or kaempferol (25μM) with E2 or triclosan restored the cellular morphology to an epithelial phenotype. In a wound-healing scratch and a transwell migration assay, triclosan enhanced migration and invasion of MCF-7 cells, but co-treatment of kaempferol or ICI 182,780 reduced the migration and invasion ability of MCF-7 cells to the control level. In addition, kaempferol effectively suppressed E2 or triclosan-induced protein expressions of EMT and metastasis promoting markers. Taken together, triclosan may be a distinct xenoestrogenic EDC to promote EMT, migration, and invasion of MCF-7 breast cancer cells through ER. On the other hand, kaempferol can be an alternative chemopreventive agent to effectively suppress the metastatic behavior of breast cancer induced by an endogenous estrogen as well as exogenous xenoestrogenic compounds including triclosan.

Lee GA ，Choi KC ，Hwang KA 《-》

Bisphenol A and nonylphenol have the potential to stimulate the migration of ovarian cancer cells by inducing epithelial-mesenchymal transition via an estrogen receptor dependent pathway.

Kim YS ，Hwang KA ，Hyun SH ，Nam KH ，Lee CK ，Choi KC ... -  《-》