HGF regulates VEGF expression via the c-Met receptor downstream pathways, PI3K/Akt, MAPK and STAT3, in CT26 murine cells

Abstract

In the present study, we assessed the involvement of hepatocyte growth factor (HGF)/c-Met signalling with vascular endothelial cell growth factor (VEGF) and hypoxia inducible factor (HIF)-1α expression in the downstream pathways phosphatidylinositol 3-kinase (PI3K)/Akt, mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) in CT26 cells, to determine the mechanisms of the potent anti-angiogenic effect of NK4. We established genetically modified CT26 cells to produce NK4 (CT26-NK4). VEGF expression in subcutaneous CT26 tumours in vivo and in culture supernatants in vitro was determined by ELISA. HIF-1α expression in nuclear extracts was evaluated by western blot analysis. VEGF and HIF-1α mRNA levels were examined by real-time reverse transcription-polymerase chain reaction (RT-PCR). The DNA binding activity of HIF-1α was evaluated using an HIF-1α transcription factor assay kit. Our results demonstrated that VEGF expression was reduced in homografts of CT26-NK4 cells, compared to those of the control cells. In vitro, VEGF expression, which was induced by HGF, was inhibited by anti-HGF antibody, NK4 and by kinase inhibitors (PI3K, LY294002; MAPK, PD98059; and STAT3, Stattic). HGF‑induced HIF‑1α transcriptional activity was also inhibited by the kinase inhibitors. Real-time RT-PCR demonstrated that HGF‑induced HIF‑1α mRNA expression was not inhibited by LY294002 and PD98059, but was inhibited by Stattic. These data suggest that the PI3K/Akt, MAPK and STAT3 pathways, downstream of HGF/c‑Met signalling, are involved in the regulation of VEGF expression in CT26 cells. HGF/c‑Met signalling may be a promising target for anti-angiogenic strategies.

The Novel VEGF Receptor/MET–Targeted Kinase Inhibitor TAS-115 Has MarkedIn VivoAntitumor Properties and a Favorable Tolerability Profile

“…HGF/MET signaling also plays a role as a proangiogenesis factor in endothelial cells independent of VEGF/VEGFR signaling (26,27). Furthermore, HGF upregulates VEGF expression and downregulates thrombospondin-1 in cancer cells (25,39). The HGF-mediated change in the expression of these factors promotes tumor angiogenesis.…”

The biological complexity of colorectal cancer: insights into biomarkers for early detection and personalized care

“…Another way by which the HGF/cMET signaling pathway contributes to tumor progression and metastases is through stimulation of angiogenesis and lymphangiogenesis, thus acting in a synergistic manner with the VEGF/VEGFR pathway ( Figure 2). Moreover, the HGF/cMET signaling pathway promotes the growth of endothelial cells and overexpression of pro-angiogenic factors, such as VEGF itself [Ding et al 2003;Zhang et al 2003;Matsumura et al 2013].…”

Interplay between VEGF-A and cMET signaling in human vestibular schwannomas and schwann cells

“…The HGF/cMET signaling pathway has been shown to interact closely with the VEGF-A signaling pathway in other physiological signaling, such as in endothelial cells, 7 and in pathological signaling, such as in adenocarcinoma 8 and glioma cells. 9 Specifically, previous research in endothelial cells shows that VEGF-A and HGF synergistically activate mitogen-activated protein kinases (MAPKs), stimulation with VEGF-A increases cMET levels, and stimulation with HGF elevates VEGFR2 levels.…”