VEGFR-1 Activation-Induced MMP-9-Dependent Invasion in Hepatocellular Carcinoma

Abstract

Aim: VEGFR-1 can promote invasion through epithelial-mesenchymal transition induction in hepatocellular carcinoma (HCC). This study aims to elucidate VEGFR-1 impact on proteolytic enzymes profile involved with invasion. Materials & methods: The effect on cell invasion was evaluated by invasive and migration assays with and without VEGFR-1 activation. The mechanism was investigated by real-time PCR, western blot and gelatin zymography using inhibitors for MMP-9. In total, 95 HCC patients were enrolled for its clinical value evaluation. Results: VEGFR-1 activation induced invasion in HCC cells with an increase in the expression and activity of MMP-9 and Snail. MMP-9 blockage effectively inhibited VEGFR-1-induced invasion. High coexpression of both in HCC predicted a worse clinical outcome. Conclusion: Data show a novel VEGFR-1 activation-to-MMP-9 mechanism promoting HCC invasion. KEYWORDS• hepatocellular carcinomaHepatocellular carcinoma (HCC) is an aggressive disease with a poor prognosis due to the tumor invasiveness, intrahepatic spread and extrahepatic metastasis [1]. HCC metastasis is frequently associated with epithelial-mesenchymal transition (EMT) and extracellular matrix (ECM) degradation using proteases including matrix metalloproteinases (MMPs) [2,3]. Understanding of the molecular mechanisms regulating the metastatic and invasive behavior of this malignant tumor is essential for improving the treatments.Activation of growth factor receptors is one of the most important mechanisms for survival and invasion of human cancers. VEGFR-1 is one of three typical membrane-bound tyrosine kinase receptors that specifically bind VEGF-B and PGF. VEGFR-1-mediated signaling promotes cancer metastasis via three major mechanisms: promotion of angiogenesis, activation of tumor cell proliferation and induction of tumor EMT, which endows tumor cell with a more invasive phenotype [4,5]. Activation of VEGFR-1 on the endothelial cells by its ligands results in the enhanced angiogenesis and metastasis. VEGFR-1 signaling facilitates malignant angiogenesis through the enhancement of endothelial migration and activity [6]. VEGFR-1 activation in breast cancer cells promotes tumor growth via activation of MAPK and PI3K/Akt signaling [7,8]. Moreover, activation of VEGFR-1 in cancer cells can also induce EMT, a critical mechanism for acquisition of invasive potential and promotion of cancer cell metastasis [4,[9][10]. Furthermore, it is reported that activation/induction of proteolytic enzyme-mediated degradation of the ECM is also one of the essential steps in carcinoma invasion [1]. Many growth factors including TGF-β, EGF and IGF-1 have the ability to enhance the cancer cell invasiveness through activation of proteolytic enzymes [11][12][13]. While the mechanisms of angiogenesis and EMT are well established, the VEGFR-1 signaling pathways that regulate the activation of proteolytic enzymes are poorly understood.For reprint orders, please contact: reprints@futuremedicine.com

The Emerging Role of Circular RNAs in Hepatocellular Carcinoma

“…The AUC of hsa_circ_0001649 was 0.63, with the cut-off value, sensitivity, and specificity of 0.0007855, 0.81 and 0.69, respectively 26 . Further studies demonstrated that knockdown of hsa_circ_0001649 by siRNA in HCC cells greatly increased the expression of several MMPs, such as MMP9, MMP10, and MMP13, indicating the possible role of hsa_circ_0001649 in regulating the invasion and metastasis of HCC 26 , 48 - 50 . Bioinformatic analysis reveals that hsa_circ_0001649 have potential binding sites of several RNA-binding proteins (RBPs), including U2 auxiliary factor 65 kDa subunit (U2AF65), Eukaryotic initiation factor 4A-III (EIF4A3) and Regulator of nonsense transcripts 1 (UPF1), implying that it may function as a protein sponge or a transcription regulator 26 .…”

Dynamics of Axl Receptor Shedding in Hepatocellular Carcinoma and Its Implication for Theranostics

“…Moreover, modulations of gene expression affect major regulators of HCC, such as c-myc, cyclin A2, cyclin D1, retinoblastoma 1, Axin1, insulin-like growth factor-II receptor/mannose-6-phosphate receptor, p16 INK4a , Yes-associated protein (YAP)1, E-cadherin, suppressors of cytokine signaling (SOCS), interleukin (IL)-6, phosphatase and tensin homolog, or cyclooxygenase 2 in HCC [14,15]. Notably, the expression of a large panel of receptor tyrosine kinases (RTKs) is increased, including ErbB receptors, fibroblast growth factor receptors, Met and its ligand hepatocyte growth factor, vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptors (PDGFRs) and TAM (Tyro3, Axl and Mer) receptors [16,17,18,19,20,21,22,23,24,25,26]. Under physiological conditions, Axl is predominantly expressed in liver endothelial cells and mostly involved in platelet aggregation and vessel integrity.…”

Loss of Caveolin-1 in Metastasis-Associated Macrophages Drives Lung Metastatic Growth through Increased Angiogenesis

“…Moreover, we showed that VEGFR1 modulation by Cav1 was responsible for the observed phenotype, because treating mice with the VEGFR1-blocking antibody MF1 abrogated the increased metastatic growth and vessel formation in Cav1 KO→WT chimeras intravenously injected with LLC cells ( Figures 5 B and 5C). Previous studies have shown that VEGFR1 activity drives Mmp9 expression in the context of cancer ( Bergers et al., 2000 , Hiratsuka et al., 2002 , Li et al., 2015 ). Accordingly, we observed a strong increase in Mmp9 expression in macrophages upon Cav1 deletion, which was inhibited after MF1 treatment ( Figure 5 D).…”