Mali Aniket V, Joshi Asavari A, Hegde Mahabaleshwar V, Kadam Shivajirao S
Center for Innovation in Nutrition Health and Disease (CINHD), Interactive Research School for Health Affairs (IRSHA), Bharati Vidyapeeth Deemed to be University (BVDU), Dhankawadi, Pune, Maharashtra 411043, India.
Pharmaceutical Sciences, Poona College of Pharmacy, Bharati Vidyapeeth Deemed to be University (BVDU), Pune, Maharashtra 411038, India.
Cancer Biol Med. 2018 May;15(2):137-156. doi: 10.20892/j.issn.2095-3941.2018.0012.
Triple-negative breast cancer (TNBC) is highly metastatic, and there is an urgent unmet need to develop novel therapeutic strategies leading to the new drug discoveries against metastasis. The transforming growth factor-β (TGF-β) is known to promote the invasive and migratory potential of breast cancer cells through induction of epithelial-mesenchymal transition (EMT) via the ERK/NF-κB/Snail signaling pathway, leading to breast cancer metastasis. Targeting this pathway to revert the EMT would be an attractive, novel therapeutic strategy to halt breast cancer metastasis.
Effects of enterolactone (EL) on the cell cycle and apoptosis were investigated using flow cytometry and a cleaved caspase-3 enzyme-linked immunosorbent assay (ELISA), respectively. Effects of TGF-β induction and EL treatment on the functional malignancy of MDA-MB-231 breast cancer cells were investigated using migration and chemo-invasion assays. The effects of EL on EMT markers and the ERK/NF-κB/Snail signaling pathway after TGF-β induction were studied using confocal microscopy, quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blot, and flow cytometry.
Herein, we report that EL exhibits a significant antimetastatic effect on MDA-MB-231 cells by almost reverting the TGF-β-induced EMT . EL downregulates the mesenchymal markers N-cadherin and vimentin, and upregulates the epithelial markers E-cadherin and occludin. It represses actin stress fiber formation via inhibition of mitogen-activated protein kinase p-38 (MAPK-p38) and cluster of differentiation 44 (CD44). EL also suppresses ERK-1/2, NF-κB, and Snail at the mRNA and protein levels.
Briefly, EL was found to inhibit TGF-β-induced EMT by blocking the ERK/NF-κB/Snail signaling pathway, which is a promising target for breast cancer metastasis therapy.
三阴性乳腺癌（TNBC）具有高度转移性，迫切需要开发新的治疗策略以实现针对转移的新药发现。已知转化生长因子-β（TGF-β）通过ERK/NF-κB/蜗牛信号通路诱导上皮-间质转化（EMT），从而促进乳腺癌细胞的侵袭和迁移潜能，导致乳腺癌转移。靶向该通路以逆转EMT将是一种有吸引力的新型治疗策略，可阻止乳腺癌转移。
分别使用流式细胞术和裂解的半胱天冬酶-3酶联免疫吸附测定（ELISA）研究肠内酯（EL）对细胞周期和细胞凋亡的影响。使用迁移和化学侵袭试验研究TGF-β诱导和EL处理对MDA-MB-231乳腺癌细胞功能恶性的影响。使用共聚焦显微镜、定量逆转录聚合酶链反应（qRT-PCR）、蛋白质印迹和流式细胞术研究TGF-β诱导后EL对EMT标志物和ERK/NF-κB/蜗牛信号通路的影响。
在此，我们报告EL对MDA-MB-231细胞具有显著的抗转移作用，几乎可逆转TGF-β诱导的EMT。EL下调间充质标志物N-钙黏蛋白和波形蛋白，并上调上皮标志物E-钙黏蛋白和闭合蛋白。它通过抑制丝裂原活化蛋白激酶p-38（MAPK-p38）和分化簇44（CD44）来抑制肌动蛋白应力纤维形成。EL还在mRNA和蛋白质水平上抑制ERK-1/2、NF-κB和蜗牛。
简而言之，发现EL通过阻断ERK/NF-κB/蜗牛信号通路抑制TGF-β诱导的EMT，这是乳腺癌转移治疗的一个有前景的靶点。
