pomolic-acid and Neoplasms

Pomolic acid (PA), an active triterpenoid from Euscaphis japonica, inhibits the proliferation of a variety of cancer cells, but the molecular mechanisms of the anti-angiogenic potential of PA have not been fully elucidated in breast cancer cells.. We investigated the molecular mechanisms underlying the anti-angiogenic effect of PA in epidermal growth factor (EGF)-responsive human breast cancer cells, MCF-7 and MDA-MB-231, and human umbilical vascular endothelial cells (HUVEC).. Effects of PA on EGF-induced HIF1α/VEGF expression in MCF-7, MDA-MB-231 and HUVEC were assayed. As to the mechanisms, EGF-mediated MAPKs, PI3K/Akt, and mTOR signaling pathway were performed. Wound healing and invasion assay, tube formation assay, immunoblot assay, real-time PCR, luciferase gene assay, electrophoretic mobility shift assay and immunofluorescence staining were used for assessment.. PA significantly and selectively suppressed EGF-induced HIF1α/VEGF expression, whereas it did not affect the expression of HIF1β in MCF-7 and MDA-MB-231. Furthermore, PA inhibited EGF-induced angiogenesis in vitro and downregulated HIF1α/VEGF expression in HUVEC. Mechanistically, we found that the inhibitory effects of PA on HIF1α/VEGF expression are associated with inhibition of HIF1α/VEGF expression through an EGF-dependent mechanism. In addition, PA suppressed the EGF-induced phosphorylation of p38-MAPK and mTOR.. PA suppresses EGF-induced HIF1α protein translation by inhibiting the p38-MAPK and mTOR kinase signaling pathways and plays a novel anti-angiogenic role.

Topics: Angiogenesis Inhibitors; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Endothelial Cells; Female; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Magnoliopsida; MCF-7 Cells; Neoplasms; Neovascularization, Pathologic; Oleanolic Acid; p38 Mitogen-Activated Protein Kinases; Phosphatidylinositol 3-Kinases; Phosphorylation; Plant Extracts; Real-Time Polymerase Chain Reaction; Signal Transduction; TOR Serine-Threonine Kinases; Triterpenes; Vascular Endothelial Growth Factor A