PMID- 25561311 OWN - NLM STAT- MEDLINE DCOM- 20160204 LR - 20181113 IS - 2211-3436 (Electronic) IS - 2211-3428 (Linking) VI - 38 IP - 2 DP - 2015 Apr TI - Chlorogenic acid inhibits hypoxia-induced angiogenesis via down-regulation of the HIF-1alpha/AKT pathway. PG - 111-8 LID - 10.1007/s13402-014-0216-2 [doi] AB - BACKGROUND: The hypoxia-inducible factor-1 (HIF-1) is known to play an important role in cellular responses to hypoxia, including the transcriptional activation of a number of genes involved in tumor angiogenesis. Chlorogenic acid (CGA), one of the most abundant polyphenols in the human diet, has been reported to inhibit cancer cell growth. The effect of CGA on tumor angiogenesis and its underlying mechanisms are, as yet, unknown. METHODS: The effect of CGA on HIF-1alpha expression was assessed by Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR) assays in A549 lung cancer cells. The transcriptional activity of the HIF-1 complex was confirmed using a luciferase assay. To assess whether angiogenic factors are increased under hypoxic conditions in these cells, vascular endothelial growth factor (VEGF) expression levels were measured by RT-PCR and Western blotting. The direct effect of CGA on human vascular endothelial cells (HUVEC) under hypoxic conditions was analyzed using in vitro assays, including tube-formation, wound healing and Transwell invasion assays. To investigate the effect of CGA on angiogenesis in vivo, we performed a Matrigel plug assay in a mouse model. Finally, the effect of CGA on AKT and ERK activation (phosphorylation) as a putative mechanism underlying the effect of CGA on VEGF-mediated angiogenesis inhibition was assessed using Western blotting. RESULTS: We found that CGA significantly decreases the hypoxia-induced HIF-1alpha protein level in A549 cells, without changing its mRNA level. CGA was, however, found to suppress the transcriptional activity of HIF-1alpha under hypoxic conditions, leading to a decrease in the expression of its downstream target VEGF. We also found that CGA can block hypoxia-stimulated angiogenesis in vitro and VEGF-stimulated angiogenesis in vivo using HUVEC cells. In addition, we found that CGA can inhibit the HIF-1alpha/AKT signaling pathway, which plays an important role in VEGF activation and angiogenesis. CONCLUSIONS: Our data indicate that CGA plays a role in the suppression of angiogenesis via inhibition of the HIF-1alpha/AKT pathway. CGA may represent a novel therapeutic option for the treatment of (lung) cancer. FAU - Park, Jin Ju AU - Park JJ AD - College of Pharmacy, Inje University, 197 Inje-ro, Gimhae, Gyeongnam, 621-749, Republic of Korea. FAU - Hwang, Su Jung AU - Hwang SJ FAU - Park, Ji-Hyeon AU - Park JH FAU - Lee, Hyo-Jong AU - Lee HJ LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20150106 PL - Netherlands TA - Cell Oncol (Dordr) JT - Cellular oncology (Dordrecht) JID - 101552938 RN - 0 (Antineoplastic Agents) RN - 0 (HIF1A protein, human) RN - 0 (Hypoxia-Inducible Factor 1, alpha Subunit) RN - 318ADP12RI (Chlorogenic Acid) RN - EC 2.7.11.1 (Proto-Oncogene Proteins c-akt) SB - IM MH - Animals MH - Antineoplastic Agents/*pharmacology MH - Blotting, Western MH - Cell Hypoxia/physiology MH - Cell Line, Tumor MH - Chlorogenic Acid/*pharmacology MH - Down-Regulation MH - Humans MH - Hypoxia-Inducible Factor 1, alpha Subunit/metabolism MH - Immunohistochemistry MH - Mice MH - Mice, Inbred C57BL MH - Neovascularization, Pathologic/*physiopathology MH - Proto-Oncogene Proteins c-akt/metabolism MH - Real-Time Polymerase Chain Reaction MH - Reverse Transcriptase Polymerase Chain Reaction MH - Signal Transduction/*drug effects EDAT- 2015/01/07 06:00 MHDA- 2016/02/05 06:00 CRDT- 2015/01/07 06:00 PHST- 2014/12/23 00:00 [accepted] PHST- 2015/01/07 06:00 [entrez] PHST- 2015/01/07 06:00 [pubmed] PHST- 2016/02/05 06:00 [medline] AID - 10.1007/s13402-014-0216-2 [doi] PST - ppublish SO - Cell Oncol (Dordr). 2015 Apr;38(2):111-8. doi: 10.1007/s13402-014-0216-2. Epub 2015 Jan 6.