Hepatoma‐derived growth factor induces tumorigenesis in vivo through both direct angiogenic activity and induction of vascular endothelial growth factor

Abstract

Hepatoma-derived growth factor (HDGF) is highly expressed in tumor cells, and stimulates their proliferation. In the present study, we investigated the role of HDGF in tumorigenesis and elucidated the mechanism of action. Stable transfectants of NIH3T3 cells overexpressing HDGF did not show significant anchorage-independent growth in soft agar assay. However, these stable transfectants overexpressing HDGF generated sarcomatous tumors in nude mice. These tumors were red-colored macroscopically, and histologically showed a rich vascularity. Immunohistochemical analysis using CD31 antibody showed new vessel formation. Recombinant HDGF stimulated proliferation of human umbilical vein endothelial cells in a dose-dependent manner, and stimulated tubule formation. ncogenesis is induced by genetic alterations of various proteins involved in the cell cycle and cellular proliferation, especially by up-regulation of oncogenic genes and/or down-regulation of tumor suppressor genes. Overexpression of growth factors, receptors for growth factors, proteins related to signal transduction from the respective receptors and positive transcriptional regulatory factors, and suppressed expression of growth-inhibitory genes, including negative signal transducers and transcriptional regulatory factors, have all been associated with tumor formation in nude mice. [1][2][3][4][5][6][7][8][9] Hepatoma-derived growth factor (HDGF) is a heparin-binding protein purified from the conditioned media of Huh-7 hepatoma cells, which proliferate autonomously in a serum-free chemically defined medium.10, 11) HDGF contains a well-conserved N-terminal amino acid sequence, which is called the hath (homologous to amino terminus of HDGF) region. 11,12) HDGF is translocated to the nucleus via nuclear localization signals and its nuclear translocation is essential for induction of cell growth activity. 13,14) It is highly expressed in fetal tissues and may be involved in development of organs, including the cardiovascular system, kidney and liver. [15][16][17][18] HDGF has mitogenic activity for some hepatocellular carcinoma (HCC) cells, in addition to fibroblasts, endothelial cells, vascular smooth muscle cells and fetal hepatocytes. 10,11,13,15,16,18,19) It is abundantly expressed in tumor cell lines, and HDGF antisense oligonucleotides suppress the proliferation of hepatoma cells expressing HDGF endogenously. 19) In human and murine models of HCC, HDGF expression increases at an early stage, even before tumor formation. Furthermore, HDGF is more abundantly expressed in HCC than in adjacent non-tumor liver tissues.20) HDGF is a unique nuclear/growth factor, possibly playing an important role in the development and progression of cancer cells.Increasing evidence suggests that HDGF might be implicated in tumorigenesis. However, whether HDGF really induces transformation of cells and tumor formation in vivo is not known. Therefore, we established stable cell lines overexpressing HDGF from NIH3T3 fibroblasts by transfection, and investigated their oncogenic p...

Molecular and functional analysis of the stem cell compartment of chronic myelogenous leukemia reveals the presence of a CD34− cell population with intrinsic resistance to imatinib

“…While modulations of genes functionally related to apoptosis 22,23,25,35,36 and DNA repair 23, 25 have already been reported by other groups, our microarray data showed, for the first time, the increased expression of pro-angiogenic factors (VEGFA, 37 HDGF, 38 RANTES/CCL5, 39 and EREG 40 ) in CML Lin Ϫ CD34 Ϫ cells versus normal counterparts ( Figure 4A).…”

Antisense to Cyclin D1 Inhibits Vascular Endothelial Growth Factor–Stimulated Growth of Vascular Endothelial Cells: Implication of Tumor Vascularization

“…SiTrio cyclin D1 and negative control small interfering RNA (siRNA) were purchased from B-Bridge International, Inc. Reporter gene assay. The VEGF gene promoter region (provided by Dr. Abraham, SIOS, Inc., CA) was inserted upstream of the luciferase reporter gene in pGVB (Toyo, Inc., Tokyo, Japan) as described previously (36). Cells were transfected with siRNA and 2 Ag reporter plasmid pGVB-VEGF and 0.025 Ag pRL-SV40 (36) in Opti-MEM I Reduced Serum Medium.…”

What drives intense apoptosis resistance and propensity for necrosis in glioblastoma? A role for Bcl2L12 as a multifunctional cell death regulator

“…71 HMGB1-RAGE interaction induces proliferation, angiogenesis, invasion, metastasis and chemotherapy-resistance. 71 Similarly, HDGF is overexpressed in many different cancers, including gastrointestinal stromal tumors (GISTs), 72 esophageal carcinoma, 73 pancreatic cancer, 74 hepatocellular carcinoma, 75 non-small cell lung cancer, 76 colorectal cancer 77 and melanoma, 78 and has potent angiogenic, 79 invasive 80 and metastatic potential. 73 Contrasting its role under pathophysiological conditions, such as gliomagenesis, necrosis can also be beneficial for an organism as it constitutes a warning system against toxic exposure.…”