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Hepatoma-derived growth factor (HDGF) is a novel multifunctional growth factor that elicits pleiotropic effects on biological processes such as lung remodeling and renal development. Recent studies demonstrated that HDGF is related to tumor proliferation, invasion, angiogenesis, and apoptosis. However, the molecular mechanism of HDGF’s involvement in apoptosis remains to be clarified. In this study, we first analyze the role of HDGF in colorectal carcinoma (CRC) progression by immunohistochemistry. Then we used small interference RNA (HDGF-siRNA) to block HDGF and assessed its effect on inducing apoptosis of CRC loVo cells. Apoptosis was detected using flow cytometry (FCM), DNA ladder analysis, and Hoechst 33258 staining. In addition, the expression levels of some apoptosis-related proteins were examined by western blot. The result showed that HDGF expression gradually increased in the colorectal carcinogenesis process. Further studies demonstrated that knock-down of HDGF can down-regulate the survivin, activate the mitochondrial pathway, and induce apoptosis in loVo cells. These findings suggest that HDGF is involved in colorectal carcinogenesis process. Further blocking HDGF exhibits potent pro-apoptotic properties in colon cancer cells. Thus, HDGF might be a potential therapeutic target for human colorectal cancer. These findings may have major implications in the treatment of colorectal cancer.

Hepatoma Derived Growth Factor (HDGF) is a nuclear protein with both mitogenic and angiogenic activity, it is highly expressed in the developing heart and vasculature. To date the mechanisms of HDGF’s function are unknown. Oligonucleotide microarray analysis was used to gain insights into HDGF function. Adenoviral expression of HDGF significantly (≥ 2 fold) downregulated a large group (66) of genes, and increased expression of a relatively small number of genes (9). Two groups of target genes which are involved in cardiovascular development and transcriptional regulation were validated by real time PCR, including the skeletal/cardiac muscle specific SET and MYND domain containing 1 (SMYD1) gene. This suggested that HDGF could function as a transcriptional repressor. In a one-hybrid system, GBD-HDGF significantly repressed reporter gene activity in a dose dependent manner. This demonstrated that HDGF has transcriptional repressive activity. Moreover, in G-7 myoblast cells, overexpression of a GFP-HDGF fusion specifically downregulated SMYD1 mRNA expression and the activity of the human SMYD1 promoter. HDGF repressed SMYD1 gene transcription through interaction with a transcriptional corepressor C-terminal binding protein (CtBP). Overexpressing of CtBP potentiated the trans-repressive activity of HDGF; on the other hand, knocking down CtBP attenuated the trans-repressive effect of HDGF. HDGF binds CtBP through a non-canonical binding motif (PKDLF) within the PWWP domain, as substitutional mutation of DL to AS abolished HDGF and CtBP interaction and diminished the trans-repressive effect of HDGF without affecting DNA binding. Finally, fluorescent microscopy studies showed that HDGF induced the nuclear accumulation of CtBP suggesting that HDGF forms a transcriptional complex with CtBP. Taken together, our data demonstrate that HDGF functions as a transcriptional repressor of the SMYD1 gene, through interaction with the transcriptional corepressor CtBP. Because of moderate conservation of the CtBP binding motif in HDGF family members, trans-repressive activity mediated by CtBP may be a common function among HDGF proteins.

Hepatoma-derived growth factor (HDGF) is a heparin-binding protein purified from the conditioned medium of the human well-differentiated hepatocellular carcinoma (HCC) cell line, HuH-7, which can proliferate autonomously in a serum-free chemically-defined medium; this factor is highly expressed in several cancer cells (Nakamura et al., 1989, 1994; Mori et al., 2004). Hepatoma-derived growth factor is an acidic 26 kDa protein consisting of 230 amino acids with no hydrophobic signal sequence in its N-terminus, and it has a high affinity to the glycosaminoglycans heparin and heparan sulphate (Nakamura et al., 1994; Dietz et al., 2002). Exogenously supplied HDGF stimulates the proliferation of fibroblasts, endothelial cells, vascular smooth muscle cells, pulmonary epithelial cells and hepatocytes, as well as HCC, lung cancer, and colon cancer cells. A possible receptor-binding site is estimated to be residing at amino acid residues 81–100 within the hath region (described below) (Abouzied et al., 2005). Indeed, exogenous HDGF stimulates the Erk phosphorylation in endothelial cells (Everett et al., 2004). Hepatoma-derived growth factor is a major member of the HDGF family of proteins which consists of HDGF and five HDGF-related proteins (HRP) (Izumoto et al., 1997; Dietz et al., 2002). The N-terminal region of HDGF is highly conserved among the other five HDGF-related proteins (HRP), and this region is called hath (homologous to the amino terminus of HDGF) region, which contains the PWWP domain (Izumoto et al., 1997). The HDGF family members are characterized based on whether they contain the hath region and nuclear localization signals (NLS) in their gene-specific regions and are targeting to the nucleus (Nakamura and Hada, 2004). Hepatoma-derived growth factor contains two nuclear localization signals (NLS) in the molecule of HDGF; the first functional nuclear localization signal (NLS1) is in the hath region and the second NLS (NLS2) is in gene-specific regions of the C-terminal region (Kishima et al., 2002a). Hepatoma-derived growth factor can traffic to the nucleus using these NLSs, especially the NLS2 in its gene-specific region, and this factor is dominantly localized in 26 Hepatocellular Carcinoma: Prognosis Using Hepatoma-Derived Growth Factor Immunohistochemistry

Hepatoma-derived growth factor (HDGF) is highly expressed in human cancer and its expression is correlated with poor prognosis of cancer. The growth factor is known to stimulate cell growth while the underlying mechanism is however not clear. Transfection with HDGF cDNA stimulated while its specific antisense oligonucleotides repressed the growth of human hepatocellular carcinoma HepG2 cells. Furthermore, knock-down of HDGF by antisense oligos also induced apoptosis in HepG2 cells and in other human cancer cells, e.g. human squamous carcinoma A431 cells. HDGF knock-down was found to induce the expression of the pro-apoptotic protein Bad and also inactivate ERK and Akt, which in turn led to dephosphorylation of Bad at Ser-112, Ser-136, and activation of the intrinsic apoptotic pathway, i.e. depolarization of the mitochondrial membrane, release of mitochondrial cytochrome c, increase in the processing of caspase 9 and 3. As HDGF knock-down not only suppresses the growth but also induces apoptosis in human cancer cells, HDGF may therefore serve as a survival factor for human cancer cells and a potential target for cancer therapy.

Hepatoma-derived growth factor is a nuclear targeted mitogen containing a PWWP domain that mediates binding to DNA. To date, almost nothing is known about the molecular mechanisms of the functions of hepatoma-derived growth factor, its routes of secretion and internalization or post-translational modifications. In the present study, we show for the first time that hepatoma-derived growth factor is modified by the covalent attachment of small ubiquitin-related modifier 1 (SUMO-1), a post-translational modification with regulatory functions for an increasing number of proteins. Using a basal SUMOylation system in Escherichia coli followed by a MALDI-TOF-MS based peptide analysis, we identified the lysine residue SUMOylated located in the N-terminal part of the protein adjacent to the PWWP domain. Surprisingly, this lysine residue is not part of the consensus motif described for SUMOylation. With a series of hepatoma-derived growth factor mutants, we then confirmed that this unusual location is also used in mammalian cells and that SUMOylation of hepatoma-derived growth factor takes place in the nucleus. Finally, we demonstrate that SUMOylated hepatoma-derived growth factor is not binding to chromatin, in contrast to its unSUMOylated form. These observations potentially provide new perspectives for a better understanding of the functions of hepatoma-derived growth factor.

Hepatoma-derived growth factor (hHDGF)-related proteins (HRPs) comprise a new growth factor family sharing a highly conserved and ordered N-terminal PWWP module (residues 1–100, previously referred to as a HATH domain) and a variable disordered C-terminal domain. We have shown that the PWWP module is responsible for heparin binding and have solved its structure in solution. Here, we show that under physiological conditions, both the PWWP module and hHDGF can form dimers. Surface plasmon resonance (SPR) studies revealed that the PWWP dimer binds to heparin with affinity that is two orders of magnitude higher ( K d = 13 nM) than that of the monomeric PWWP module ( K d = 1.2 μM). The monomer–dimer equilibrium properties and NMR structural data together suggest that the PWWP dimer is formed through a domain-swapping mechanism. The domain-swapped PWWP dimer structures were calculated on the basis of the NMR data. The results show that the two PWWP protomers exchange their N-terminal hairpin to form a domain-swapped dimer. The two monomers in a dimer are linked by the long flexible L2 loops, a feature supported by NMR relaxation data for the monomer and dimer. The enhanced heparin-binding affinity of the dimer can be rationalized in the framework of the dimer structure.

The role of hepatoma-derived growth factor (HDGF), a novel nuclear-targeted vascular smooth muscle cell (SMC) mitogen in vascular injury is unknown. We hypothesized that HDGF plays a role in SMC proliferation and migration in formation of the neointima after balloon injury of the rat carotid. Using co-immunohistochemical staining, HDGF and proliferating cell nuclear antigen (PCNA) were co-expressed in 80% of nuclei of neointimal cells 7 d post carotid balloon injury with HDGF. The HDGF-positive medial and neointimal cells were smooth muscle actin negative and therefore likely represented a subgroup of SMC that have undergone phenotypic switching. Utilizing modified Boyden chamber migration assays, adenoviral-expressed HDGF in mouse SMC increased migration 10-fold (20 versus 2). HDGF gene silencing reduced both SMC proliferation and migration. In conclusion, HDGF is highly expressed in the media and neointima post balloon injury, a SMC mitogen and positive regulator of cell migration. We speculate that HDGF is involved in the SMC proliferative and migratory response to injury resulting in neointimal formation.

Purpose: Hepatoma-derived growth factor (HDGF) is a unique nuclear/growth factor and might play an important role in the development and progression of carcinomas. In the present study, association of HDGF expression with recurrence and prognosis of gastric carcinoma was examined. Patients and Methods: HDGF expression in 317 patients with gastric carcinoma (233 males and 84 females) with ages ranging from 26 to 81 years (median, 60 years) was analyzed by immunohistochemistry. Samples with >90% of tumor cells to express positive immunoreactivity similar to or stronger than that in endothelial cells both for nucleus and cytoplasm were regarded as HDGF index level 2, and others as HDGF index level 1. Results: One hundred and eighty-two cases showed level 1 HDGF expression, whereas 135 cases showed level 2 HDGF expression. Patients with level 2 expression showed higher rates of proximal tumor location (P < 0.0001), large tumor size (P < 0.0001), infiltrative tumor growth (P < 0.0001), presence of vascular and lymphatic invasion (P < 0.0001 for both), presence of lymph node metastasis (P < 0.0001), deep tumor invasion (P < 0.0001), and poorer disease-free and overall survival (P < 0.0001 for both) compared to those with level 1 expression. Multivariate analysis revealed HDGF expression level as an independent prognosticator for disease-free and overall survival. Conclusion: HDGF expression level was shown to be a prognostic factor for gastric carcinoma.

Background Hepatoma-derived growth factor (HDGF) belongs to a polypeptide family containing five additional members called HDGF related proteins 1–4 (HRP-1 to -4) and Lens epithelial derived growth factor. Whereas some family members such as HDGF and HRP-2 are expressed in a wide range of tissues, the expression of others is very restricted. HRP-1 and -4 are only expressed in testis, HRP-3 only in the nervous system. Here we investigated the expression of HDGF, HRP-2 and HRP-3 in the central nervous system of adult mice on the cellular level by immunohistochemistry. In addition we performed Western blot analysis of various brain regions as well as neuronal and glial cell cultures. Results HDGF was rather evenly expressed throughout all brain regions tested with the lowest expression in the substantia nigra. HRP-2 was strongly expressed in the thalamus, prefrontal and parietal cortex, neurohypophysis, and the cerebellum, HRP-3 in the bulbus olfactorius, piriform cortex and amygdala complex. HDGF and HRP-2 were found to be expressed by neurons, astrocytes and oligodendrocytes. In contrast, strong expression of HRP-3 in the adult nervous system is restricted to neurons, except for very weak expression in oligodendrocytes in the brain stem. Although the majority of neurons are HRP-3 positive, some like cerebellar granule cells are negative. Conclusion The coexpression of HDGF and HRP-2 in glia and neurons as well as the coexpression of all three proteins in many neurons suggests different functions of members of the HDGF protein family in cells of the central nervous system that might include proliferation as well as cell survival. In addition the restricted expression of HRP-3 point to a special function of this family member for neuronal cells.

Untersuchung der Butyrateffekte auf die Genexpression von Zellkulturen während der Adenom-Karzinom-Sequenz mit Hilfe von Microarrays. Analyse des HDGF-Genclusters. Verwendete Zellkulturen Geki2, HT29 und SW620, Examination of butyrate effects on genexpression of cellculteres during adenom-carcinom-sequence by use of microarrays. Analysis of hdgf-gencluster. USed cellcultures Geki2, HT29 und SW620.

Human immunodeficiency virus type 1 (HIV-1) integrase (IN) functions in cells within the context of high molecular weight preintegration complexes (PICs). Lens epithelium-derived growth factor (LEDGF) transcriptional coactivator/p75 and hepatoma-derived growth factor related protein 2 (HRP2) tightly bind to HIV-1 IN and stimulate its integration activity in vitro. Here, we show that each recombinant host cell factor efficiently reconstitutes the in vitro activity of HIV-1 PICs disrupted for functional integration by pre-treatment with high concentrations of salt. Mutational analysis reveals that both the IN-binding and DNA-binding activities of LEDGF/p75 contribute to functional PIC reconstitution. We also investigate a role(s) for these proteins in HIV-1 infection by using short-interfering RNA. HIV-1 infection was essentially unaffected in HeLa-P4 cells depleted for LEDGF/p75, HRP2, or both proteins. We conclude that cells knocked-out for LEDGF/p75 and/or HRP2 will be useful genetic tools to address the roles of these host cell factors in HIV-1 replication.

Hepatoma-derived growth factor (HDGF), unrelated to hepatocyte growth factor, is a heparin-binding protein originally purified from human hepatoma HuH-7 cells. HDGF exhibits mitogenic activities for certain hepatoma cells, fibroblasts and vascular smooth muscle cells, and angiogenic activities through nuclear targeting. Recently, HDGF was found to be a mitogen for lung epithelial cells in vitro and in vivo. This suggests that HDGF may play a critical role in the development and progression of lung cancer. We investigated, immunohistochemically, the relationship between HDGF expression and clinicopathological variables, and the prognostic significance of HDGF in 102 patients with completely resected non-small-cell lung cancer (NSCLC: 70 adenocarcinomas and 32 squamous cell carcinomas). To address the mechanism of action of HDGF, we evaluated the contribution of HDGF to tumor cell proliferation and intratumor angiogenesis using anti-Ki-67 and anti-CD31 antibodies, respectively. HDGF expression was strongly detected in the nucleus of cancer cells; the HDGF-labeling index (LI) was 20-95% (median 64.5%). There was no significant association between HDGF-expression level and clinicopathological variables. Patients with NSCLC showing a high HDGF-LI (> or =65%) had significantly worse overall and disease-free survivals than those with NSCLC showing a low HDGF-LI. Multivariate analysis revealed that HDGF is a significant independent prognostic factor, more powerful than pathological stage. Moreover, HDGF expression correlated with Ki-67-LI and intratumor microvessel density. We consider HDGF as a useful prognostic marker for patients with completely resected NSCLC and it may play a critical role in the pathobiology of lung cancer through its mitogenic and angiogenic activities.

The vertebrate intestine is a model for investigating inductive cellular interactions and the roles of epithelial stem cells in tissue regeneration,and for understanding parallels between development and cancer. We have used serial analysis of gene expression to measure transcript levels across stages in mouse intestine development. The data(http://genome.dfci.harvard.edu/GutSAGE)identify novel differentiation products, potential effectors of epithelial-mesenchymal interactions, and candidate markers and regulators of intestinal epithelium. Transcripts that decline significantly during intestine development frequently are absent from the adult gut. We show that a significant proportion of such genes may be reactivated in human colon cancers. As an example, hepatoma-derived growth factor (HDGF) mRNA is expressed prominently in early gut tissue, with substantially reduced levels after villous epithelial differentiation. HDGF expression is dramatically increased in human colorectal cancers, especially in tumors proficient in DNA mismatch repair, and thus represents a novel marker for a distinctive tumor subtype. HDGF overexpression in fetal intestine explants inhibits maturation,suggesting a role in epithelial differentiation. To investigate the molecular basis for HDGF functions, we isolated components of a nuclear HDGF complex,including heterogeneous nuclear ribonucleoproteins implicated in processing RNA. These genes are regulated in tandem with HDGF during intestine development and one factor, TLS/Fus, is commonly overexpressed in colon cancers. Tumor expression of fetal genes may underlie similarities between developing and malignant tissues, such as self-renewal, invasion and angiogenesis. Our findings also advance understanding of HDGF functions and implicate this developmentally regulated gene in RNA metabolic pathways that may influence malignant behaviors in colorectal cancer.

Hepatoma-derived growth factor (HDGF) is a heparin-binding proliferating factor originally isolated from conditioned medium of the hepatoma-derived cell line HuH-7. HDGF has greatest homology in an amino acid sequence with high mobility group 1 (HMG1), which has been characterized as a DNA-binding, inflammatory, and potent neurite outgrowth molecule. HDGF is reported to be widely expressed and act as a growth factor in many kinds of cells. However, it has not been investigated in the nervous system. Here, we show by Western blot analysis that HDGF is present in the mouse brain from the embryonic period until adulthood. In situ hybridization and immunohistochemical analyses revealed that HDGF was expressed mainly in neurons, and HDGF protein was localized to the nucleus. HDGF and high mobility group 1 were secreted under physiological conditions and released extracellularly in necrotic conditions. Furthermore, we showed that exogenously supplied HDGF had a neurotrophic effect and was able to partially prevent the cell death of neurons in which endogenous HDGF was suppressed. Therefore, we propose that HDGF is a novel type of neurotrophic factor, on account of its localization in the nucleus and its potential to function in an autocrine manner under both physiological and pathological conditions throughout life.

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. Furthermore, vascular endothelial growth factor (VEGF) was detected immunohistochemically in the tumor tissues. Transient expression of HDGF induced both VEGF gene and protein expression as demonstrated by a reporter assay using VEGF gene promoter. The administration of anti-VEGF neutralizing antibody significantly suppressed, but did not block, the tumor growth of HDGF-overexpressing cells in nude mice. Thus, these findings suggested that HDGF-induced tumor formation in vivo involves induction of VEGF as well as direct angiogenic activity.

For isolation of novel cellular transforming genes that potentially participated in hepatocarcinogenesis, we conducted anchorage-independent growth (AIG) assays on 10 human liver cancer cell lines and observed strong AIG capabilities in PLC5 and Huh7 but negligible in Tong cells. After cloning of genes by differential subtractive chain reactions (DSC) from strong AIG to AIG negative cells, we sequenced 2304 clones and identified 245 genes. After four stringent criteria for selection of transforming genes among DSC clones, our results of quantitative RT-PCR analysis indicated that six genes, DDX3, EIF3S2, CLIC1, HDGF, GPC3, and HSPCA were overexpressed in 64%, 62%, 60%, 58%, 49%, and 47%, respectively, of 45 hepatocellular carcinoma (HCC) tissues. The results of cellular transformation capability by AIG assays indicated that the transfectants of EIF3S2 showed the strongest (> 100-fold), DDX3 and CLIC1 were moderate, GPC3 and HSPCA were weak, and HDGF was none in forming colonies in soft agar. Together, our results suggested that Tong is a suitable human cell line for screening of overexpressed and/or cellular transforming genes. In addition, our results suggested that diverse functions of cellular transforming genes in various biological pathways could transform human Tong cells and potentially reveal new targets for drug development of HCC.

Hepatoma-derived growth factor (HDGF) is involved in hepatocarcinogenesis, as well as in liver development and regeneration. This study investigated the correlation of HDGF expression with differentiation and prognosis of hepatocellular carcinoma (HCC).HDGF expression in 100 patients with HCC (81 men and 19 women) with ages ranging from 34 to 81 years (median, 61 years) receiving surgical treatment was analyzed by immunohistochemistry. HDGF messenger RNA expression was evaluated in 10 cases by reverse transcription-polymerase chain reaction. The immunostaining pattern in HCCs was categorized as a positive HDGF index (showing positive staining in90% of tumor cells in both nucleus and cytoplasm) or a negative HDGF index (all others).Twenty-seven cases (27%) showed a positive and 73 (73%) showed a negative HDGF index. HDGF messenger RNA expression was significantly higher in four cases with a positive HDGF index than in six with a negative index. Cases with well-differentiated histological characteristics showed a higher rate of positive HDGF index than those with a poorly differentiated subtype. Univariate and multivariate analysis revealed significantly poorer disease-free and overall survivals in patients with a positive HDGF index compared with patients with a negative index.These findings suggest the potential utility of HDGF immunohistochemistry in determining the prognosis of HCC.

Background and Aim: The present study investigated the expression of hepatoma-derived growth factor (HDGF) in human hepatocellular carcinoma (HCC) and in the liver during hepatocarcinogenesis in two rodent models. Methods: Expression of HDGF was analyzed using northern blotting and immunohistochemistry in the human and rodent models. Results: Hepatoma-derived growth factor was more highly expressed in HCC than in the adjacent liver in humans with hepatitis, as shown by northern blotting. Using immunohistochemistry with the specific anti-HDGF antibody, HDGF was more strongly and frequently expressed in the nucleus and cytoplasm of HCC cells than in the adjacent normal hepatocytes. Hepatoma-derived growth factor was also more strongly expressed in the tumors than in the adjacent fatty liver of fatty liver Shionogi (FLS) mice, than in the cirrhotic liver of choline-deficient amino acid feeding rats, as shown by northern blotting and immunohistochemistry. In the liver of FLS mice, HDGF expression increased gradually from the age of 24 weeks through to 52 weeks after birth, showing that HDGF expression was already increased at an early stage before tumor development. In the non-tumorous liver with fatty change, the foci expressing HDGF appeared at 24 weeks of age, which were the activated macrophage clusters with enhanced DNA synthesis and fat droplets. It is suggested that HDGF was secreted or released from these foci and stimulated hepatocyte proliferation in a paracrine manner in FLS mice, and stimulated the proliferation of hepatic tumor cells in an autocrine manner. Conclusions: The present findings suggest that HDGF plays an important role in the development or progression of HCC in humans and rodents.

Lung epithelial cells have an integral role in the maintenance of lung homeostasis; however, the regulatory mechanism thereof has not been fully clarified. Recently, hepatoma-derived growth factor (HDGF) was reported to be involved in organ development and remodeling through its mitogenic effect. We investigated the biological role of HDGF in lung remodeling. HDGF was more highly expressed in the lungs of idiopathic pulmonary fibrosis, chiefly in the epithelial cells, than in control nonfibrotic lungs. We also confirmed the expression of HDGF protein and mRNA in the lungs of bleomycin-instilled mice, mainly in the bronchial and alveolar epithelial cells, by immunohistochemical analysis and in situ hybridization. We found that recombinant HDGF promoted DNA synthesis in rat alveolar epithelial cells and A549 cells in vitro. Endogenous HDGF overexpressed by gene transfer was translocated into the nucleus and promoted the proliferation of A549 cells. In vivo intratracheal instillation of recombinant HDGF induced the proliferation of bronchial and alveolar epithelial cells without causing marked interstitial inflammation. These findings suggest that HDGF may be involved in lung remodeling after injury by promoting the proliferation of lung epithelial cells, probably in an autocrine manner.

Hepatoma Derived Growth Factor (HDGF) was originally identified as a secreted mitogen from the human hepatoma cell line Huh-7. Although initially thought to be a cytoplasmic protein, it became clear that HDGF is a nuclear targeted protein containing a canonical bipartite nuclear localization sequence. In the developing vasculature HDGF is highly expressed in the nucleus of smooth muscle and endothelial cells. HDGF expression in smooth muscle in particular, declines after birth in larger arteries only to be re-expressed with vascular injury in cells of the highly proliferative neointima. In addition, levels of HDGF have recently been shown to be elevated in a number of cancers, suggesting a potential role in cancer development. Because of these roles, HDGF is a potential target for drug design. This review will describe current knowledge about the biochemical functioning of the protein and identify potential avenues for drug development.

The identification and characterization of hepatic stem cell compartments is the key to resolving clinical disorders and diseases in the liver. Hepatoblasts (or early fetal hepatocytes) fulfill several criteria of hepatic stem cells during liver development. Unlike mature hepatocytes, immature fetal hepatocytes can proliferate autonomously in the absence of any growth factors in vitro. However, the regulation of fetal hepatocyte proliferation remains unclear. Recently, we identified a novel factor, hepatoma-derived growth factor (HDGF), from the human hepatoma-derived cell line HuH-7, which autonomously proliferate in serum-free defined medium. Here, we focus on the functional roles of HDGF, and review several molecules involved in the growth regulation of hepatocytes in the immature stage.

Hepatoma-derived growth factor (HDGF)-related proteins (HRPs) comprise a family of polypeptides named after HDGF, which was identified by its mitogenic activity towards fibroblasts. In the present study, we describe a hitherto unknown HRP, termed HRP-4. The cDNA of bovine HRP-4 (bHRP-4) predicts a polypeptide of 235 amino acids. Northern- and Western-blot analyses of various bovine tissues demonstrated that HRP-4 is only expressed in the testis. Recombinantly produced bHRP-4 and murine HDGF (mHDGF) histidine-tagged polypeptides display growth-factor activity for cultured primary human fibroblasts at an optimum concentration of 1ng/ml in serum-free medium. The growth-factor activity declines with increasing concentrations to reach background levels at 1μg/ml. The expression of the fusion proteins, bHRP-4–green fluorescent protein and mHDGF–green fluorescent protein, in HEK-293 cells demonstrates nuclear localization of the proteins. bHRP-4 and mHDGF bind to the glycosaminoglycans heparin and heparan sulphate, but not to chondroitin sulphate. Affinity constants determined for these interactions are between 6 and 42nM. Comparison of the bHRP-4 amino acid sequence with HRP-1–3 and p52/75/lens epithelium-derived growth factor (LEDGF) shows that these proteins share a conserved N-terminal part of 91 amino acids but have C-termini of different lengths and charge. This demonstrates the modular structure of these proteins and allows its classification into three groups based on charge, size and sequence comparison. HRP-4, HRP-1 and HDGF are small acidic proteins, HRP-3 is a small basic protein, and HRP-2 and p52/75/LEDGF are larger basic proteins.

Hepatoma derived growth factor (HDGF) is a mitogenic growth factor in the progression of human glioma. In this paper, we study the gliomagenesis role of HDGF in syngenic glioma rat model by Lenti-virus sh-HDGF (LV-shHDGF) infection. The tumor inhibition of HDGF depletion in rat glioma C6 cells was measured by MRI scanning. We found all glioma tumors growth after implanting but only HDGF knock down tumors had a significant reduction in the tumor size at the 4th-week MRI-scanning. After tumor volume was quantified on serial brain section, we found a 10-folds of reduction in the tumor size was observed in HDGF knock down tumors than scrambles (p Note: This abstract was not presented at the meeting. Citation Format: Li-Feng Liu, Shu-Shong Hsu, Chih-Hao Chen. Downregulated expression of hepatoma-derived growth factor (HDGF) reduces glioma cancer cell tumor growth and angiogenesis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2786. doi:10.1158/1538-7445.AM2014-2786

Hepatoma-derived growth factor (HDGF) is the first member of a new gene family that contains the HATH (homologous to the amino-terminus of HDGF) region in the N-terminal region and nuclear localization signals in the remaining parts of the sequence and traffic to the nucleus. HDGF was purified from the conditioned medium of HuH-7 hepatoma cells by DNA synthesis stimulating activity for Swiss 3T3 cells. HDGF stimulates the proliferation of endothelial cells, vascular smooth muscle cells, some hepatoma cells, and fibroblasts. HDGF is ubiquitously expressed in normal tissues, predominantly in testis, kidney, liver, heart, and brain. Recent studies have indicated that HDGF may play important roles in fetal organ development and tissue repair, such as renal glomerular formation and vascular smooth muscle cell proliferation during vascular development and neointima formation. HDGF was highly expressed in fetal liver and mainly in fetal hepatocytes with little expression in hematopoietic cells. HDGF expression in fetal hepatocytes decreased in accordance with the differentiation to mature hepatocytes. HDGF expression was significantly induced in regenerating liver after partial hepatectomy and drug-induced liver damage in adult liver. We assume that HDGF is significantly involved in liver development and regeneration.

Hepatoma-derived growth factor (HDGF) is the first member identified of a new family of secreted heparin-binding growth factors highly expressed in the fetal aorta. The biologic role of HDGF in vascular growth is unknown. Here, we demonstrate that HDGF mRNA is expressed in smooth muscle cells (SMCs), most prominently in proliferating SMCs, 8-24 hours after serum stimulation. Exogenous HDGF and endogenous overexpression of HDGF stimulated a significant increase in SMC number and DNA synthesis. Rat aortic SMCs transfected with a hemagglutinin-epitope-tagged rat HDGF cDNA contain HA-HDGF in their nuclei during S-phase. We also detected native HDGF in nuclei of cultured SMCs, of SMCs and endothelial cells from 19-day fetal (but not in the adult) rat aorta, of SMCs proximal to abdominal aortic constriction in adult rats, and of SMCs in the neointima formed after endothelial denudation of the rat common carotid artery. Moreover, HDGF colocalizes with the proliferating cell nuclear antigen (PCNA) in SMCs in human atherosclerotic carotid arteries, suggesting that HDGF helps regulate SMC growth during development and in response to vascular injury.

Background/Purpose: The mechanisms by which static airway pressures in the developing lung affect development are unknown. The in vitro murine fetal lung model with airway ligation reproduces the phenomenon of intraluminal airway pressure in developing lungs. We have applied the technique of differential display of mRNAs to fetal murine lungs that were maintained in organ culture with and without tracheal ligation. The goal of this investigation was to identify genes that are induced or enhanced by airway pressure during lung development. Methods: Fetuses were harvested from CD-1 mice on gestational day (Gd) 14. The lungs were removed and trachea either transected or ligated and organ cultured for 7 days. Total RNA was extracted from cultured unligated controls and ligated lungs. Reverse transcription (RT) of the purified total RNA from each pooled sample was performed with anchor primer H-T 11 G or C and one of 24 arbitrary primers followed by polymerase chain reaction (PCR) of the RT mixtures. PCR products were electrophoresed on a DNA sequencing gel. Differentially expressed cDNA bands of interest were cut from the dried gel. Each cDNA was then reamplified. Reamplified cDNAs were extracted, PCR amplified, cloned, and sequenced for homology to existing sequences in the GenBank database. Results: Sequencing identified 4 differentially expressed genes enhanced by tracheal ligation: hepatoma-derived growth factor (HDGF), ribosomal protein S24, stathmin, and parathyroid hormone (PTH). Conclusions: Genes enhanced by airway pressure or tracheal ligation are mitogenic for fibroblasts, correlate with cell proliferation, regulate cell proliferation and differentiation, and may play a role in growth in distal lung and type II cell differentiation. Further work is necessary to identify the mechanisms by which these genes influence lung maturational processes. J Pediatr Surg 35:113-119. Copyright © 2000 by W.B. Saunders Company.

Hepatoma-derived growth factor (HDGF) and HDGF-related proteins (HRP) belong to a gene family with a well-conserved amino acid sequence at the N-terminus (the hath region). A new member of the HDGF family in humans and mice was identified and cloned; we call it HRP-3. The deduced amino acid sequence from HRP-3 cDNA contained 203 amino acids without a signal peptide for secretion. HRP-3 has its 97-amino-acid sequence at the N-terminus, which is highly conserved with the hath region of the HDGF family proteins. It also has a putative bipartite nuclear localizing signal (NLS) sequence in a similar location in its self-specific region of HDGF and HRP-1. Northern blot analysis shows that HRP-3 is expressed predominantly in the testis and brain, to an intermediate extent in the heart, and to a slight extent in the ovaries, kidneys, spleen, and liver in humans. Transfection of green fluorescent protein (GFP)-tagged HRP-3 cDNA showed that HRP-3 translocated to the nucleus of 293 cells. GFP-HRP-3 transfectants significantly increased their DNA synthesis more than cells transfected with vector only. The HRP-3 gene was mapped to chromosome 15, region q25 by FISH analysis. These findings suggest that a new member of the HDGF gene family, HRP-3, may function mainly in the nucleus of the brain, testis, and heart, probably for cell proliferation.

Boosting angiogenesis is a crucial process to enhance tissue growth in tissue engineering (TE). Hepatoma-derived growth factor (HDGF) has been identified as an angiogenic factor, but its involvement in angiogenesis in an arteriovenous loop-based TE chamber developed by the laboratory is unclear. In this study, the authors first examined the effects of HDGF on angiogenic responses in endothelial cells and in a corneal model of neovascularization, and then characterized the expression of HDGF in the TE chamber. HDGF (1-500 ng/mL) induced concentration-dependent angiogenic responses in human endothelial cells in vitro (proliferation, migration, and tube formation). Local application of HDGF stimulated neovascularization in a rat model of corneal angiogenesis. In the TE chamber, there was an increase in blood vessel volume from day 3 to day 14. Immunofluorescence microscopy revealed that HDGF is highly expressed in the neovessels in the chamber. Peak expression of HDGF (day 3) coincided with the infiltration of inflammatory cells, and the mRNA level of endogenous HDGF correlated with that of tumor necrosis factor α (TNFα). In vitro, TNFα stimulated HDGF expression in endothelial cells. The data suggest that HDGF may be involved in angiogenic responses in the TE chamber and the proinflammatory cytokine TNFα may have a pivotal role in stimulating HDGF expression. Enhancing HDGF signaling may be a new approach to extend vascularization for TE. © 2013 National Taiwan University.

Gold nanoparticles (AuNPs) have been widely studied for use in disease therapeutics as targeting and imaging agents, drug delivery vehicles and as self-therapeutics. When AuNPs interact with the biological milieu they form a corona layer, which is predominantly composed of proteins. The outer “soft” layer is dynamic and here proteins are free to exchange over time. The inner “hard” layer on the other hand consists of proteins firmly bound to the NP surface. The Vromans effect predicts that given a limited surface area, low affinity, high abundance proteins, that first attach to the surface, are over time replaced by high affinity, low abundance proteins. Our aim was to enrich low abundance proteins on the AuNP surface to probe for differentially expressed proteins that are not detected by traditional methods of protein identification. We studied the binding of ovarian cell lysates (cancerous and non cancerous) to 10 nm sized positively and negatively charged AuNPs. The formation of corona around the AuNPs was characterized by dynamic light scattering and zeta potential measurements. The composition of the protein corona was identified using mass spectrometry. Proteins were also identified from the cell lysate pool to serve as a control to assess protein enrichment on NP surface. Using this approach, Hepatoma Derived Growth Factor (HDGF) was identified as a low abundance protein that was detected by mass spectrometry in cancer cells only after enrichment on the surface of positively charged AuNPs. HDGF is overexpressed in multiple ovarian cancer cells lines and knock down using siRNA shows decrease in cell proliferation, G2/M arrest and apoptosis. This suggests an important role of HDGF in the tumorigenicity of ovarian cancer, which could serve as an important therapeutic target for the disease. Citation Format: Karuna Giri, Rochelle Arvizo. Detecting low abundance therapeutic targets for ovarian cancer using engineered gold nanoparticles. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3215. doi:10.1158/1538-7445.AM2013-3215

Cutaneous malignant melanoma is the fastest increasing malignancy in humans. Hepatoma-derived growth factor (HDGF) is a novel growth factor identified from human hepatoma cell line. HDGF overexpression is correlated with poor prognosis in various types of cancer including melanoma. However, the underlying mechanism of HDGF overexpression in developing melanoma remains unclear. In this study, human melanoma cell lines (A375, A2058, MEL-RM and MM200) showed higher levels of HDGF gene expression, whereas human epidermal melanocytes (HEMn) expressed less. Exogenous application of HDGF stimulated colony formation and invasion of human melanoma cells. Moreover, HDGF overexpression stimulated the degree of invasion and colony formation of B16–F10 melanoma cells whereas HDGF knockdown exerted opposite effects in vitro. To evaluate the effects of HDGF on tumour growth and metastasis in vivo, syngeneic mouse melanoma and metastatic melanoma models were performed by manipulating the gene expression of HDGF in melanoma cells. It was found that mice injected with HDGF-overexpressing melanoma cells had greater tumour growth and higher metastatic capability. In contrast, mice implanted with HDGF-depleted melanoma cells exhibited reduced tumor burden and lung metastasis. Histological analysis of excised tumors revealed higher degree of cell proliferation and neovascularization in HDGF-overexpressing melanoma. The present study provides evidence that HDGF promotes tumor progression of melanoma and targeting HDGF may constitute a novel strategy for the treatment of melanoma.

This report describes the localization of the human hepatoma-derived growth factor (HDGF) gene to human chromosome Xq25 using fluorescence in situ hybridization. Homology to the high-mobility group (HMG)-1 protein was also demonstrated. 13 refs., 1 fig.

PURPOSE. Retinal ganglion cell (RGC) degeneration is an important cause of visual impairment and can be modeled by optic nerve transection, which causes the death of 90% of RGCs within 14 days postaxotomy. We performed a proteomic study to identify and quantify proteins in the rat retina after optic nerve transection. Our goal was to isolate potential targets for therapeutic intervention to prevent RGC degeneration. METHODS. iTRAQ proteomics was used to analyze adult rat retinas at 1, 3, 4, 7, 14, and 21 days postaxotomy. Hepatomaderived growth factor (HDGF), a target identified by iTRAQ, was delivered by intraocular injections. Wortmannin or PD98059 were coadministered with HDGF to determine if the protective effects of HDGF are dependent on PI3 kinase or MAP kinase activity, respectively. RESULTS. At a false-discovery rate of 5%, 216 proteins were identified by iTRAQ proteomics, 71 of which showed changes in expression ( 1.3·) at one time point after injury: 52 proteins had expression peaks, whereas 19 showed downward expression spikes. Levels of GAPDH did not change after axotomy. Among these differentially expressed proteins was HDGF. HDGF delivery significantly increased RGC survival compared with control treatments, and increased Akt phosphorylation in the retina at 24 hours after intraocular injection. RGC rescue by HDGF was dependent on both MAP kinase and PI3 kinase activity in the retina. CONCLUSIONS. We have identified numerous proteins that are differentially regulated at key time points after axotomy, and how the temporal profiles of their expression parallel RGC death. Using these data, we showed that HDGF is a potent neuroprotective factor for injured adult RGCs. (Invest Ophthalmol Vis Sci. 2012;53:3973‐3989) DOI:10.1167/ iovs.11-8350

Hepatoma derived growth factor (HDGF) is a neurotrophic factor found in mouse spinal cord and hippocampal neurons. In various malignant tumors, the role of HDGF in tumor progression and its use as a diagnostic biomarker or therapeutic target have been extensively explored. However, the prognostic function and mitogenic role of HDGF in gliomagenesis is yet to be verified. In this study, we found a significant incidence of HDGF prevalence between the different pathological types and stages of glioma in 105 patients. We also found a prognostic significance in 41 glioblastoma multiforme (GBM) patients with the prevalence of nucleus HDGF predicts the short survival of GBM after surgery. To delineate the mitogenic role of HDGF in gliomagenesis, an adenoviral-expressed HDGF small interfering RNA (Ad-HDGF siRNA) was used to knock down the expression of nucleus HDGF. After knocking down the nuclear HDGF expression in human GBM cells, cell growth and cell invasion and induction on apoptosis by caspase-3 activation were significantly inhibited. We concluded that HDGF is a mitogenic growth factor in the progression of glioma and it can be a useful prognostic marker for GBM and therapeutic target for clinical management of glioma in the future. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5627. doi:1538-7445.AM2012-5627

Background & Aims: Unusual hypervascularity is a hallmark of human hepatocellular carcinoma (HCC). Angiogenesis is essential for tumorigenesis and metastasis. While microRNA (miRNA) deregulation is implicated in carcinogenesis, the role of miRNAs in tumor angiogenesis remains unknown. Methods: MiRNAs deregulated in HCC were identified using array-based miRNA profiling. A luciferase reporter assay was used to confirm target association between miR-214 and hepatoma-derived growth factor (HDGF). Tube formation and in vivo angiogenesis assays were performed to validate the roles of miR-214 and HDGF in angiogenesis. Results: Downregulation of miR-214 was associated with HCC progression and poor clinical outcome. Ectopic expression of miR-214 suppressed cell proliferation and xenograft tumor growth and depressed the vascularity of the tumor and its surrounding tissues. The genes downregulated by ectopic expression of miR-214 were involved in the regulation of apoptosis, cell cycle, and angiogenesis. Integrated analysis implicated HDGF as a downstream target of miR-214. Conditioned medium of HCC cells contained bioactivity to stimulate tube formation of human umbilical vein endothelial cells, which was abolished by pretreatment of the conditioned media with HDGF antibodies, and silencing of HDGF expression or ectopic expression of miR-214 of the donor HCC cells. The angiogenic activity of the conditioned media lost by ectopic expression of miR-214 in the donor cells was restored by supplementation with recombinant HDGF. In vivo tumor angiogenesis assays showed significant suppression of tumor vascularity by ectopic expression of miR-214. Conclusions: A novel miR-214/HDGF paracrine pathway contributes to hypervascularity of HCC and is a candidate target for anti-HCC therapy. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5274. doi:1538-7445.AM2012-5274

Background HDGF is a growth factor which is overexpressed in a wide range of tumors. Importantly, expression levels were identified as a prognostic marker in some types of cancer such as melanoma. Methods To investigate the presumed oncogenic/transforming capacity of HDGF, we generated transgenic mice overexpressing HDGF in melanocytes. These mice were bred with mice heterozygous for a defective copy of the Ink4a tumor suppressor gene and were exposed to UV light to increase the risk for tumor development both genetically and physiochemically. Mice were analyzed by immunohistochemistry and Western blotting. Furthermore, primary melanocytes were isolated from different strains created. Results Transgenic animals overexpressed HDGF in hair follicle melanocytes. Interestingly, primary melanocytes isolated from transgenic animals were not able to differentiate in vitro whereas cells isolated from wild type and HDGF-deficient animals were. Although, HDGF-/-/Ink4a+/- mice displayed an increased number of epidermoid cysts after exposure to UV light, no melanomas or premelanocytic alterations could be detected in this mouse model. Conclusions The results therefore provide no evidence that HDGF has a transforming capacity in tumor development. Our results in combination with previous findings point to a possible role in cell differentiation and suggest that HDGF promotes tumor progression after secondary upregulation and may represent another protein fitting into the concept of non-oncogene addiction of tumor tissue.

Hepatoma-derived growth factor related protein 3 (HDGFRP3) belongs to the HDGF polypeptide family. Expression of HDGF is a prognostic factor for NSCLC, pancreatic and gastrointestinal tumors, and silencing of HDGF suppressed cell proliferation, migration and invasion of squamous lung cancer cells. Here we investigated the expression of HDGFRP3 in various tumor cell lines by quantitative PCR and western blot analysis. HDGFRP3 is highly expressed and secreted from neuroblastoma (NB) cell lines. The presence of high levels of HDGFRP3 was confirmed in two animal models of human NB. Since HDGFRP3 shares a conserved Pro-Trp-Trp-Pro motif (PWWP) domain with its family members, we assessed whether it could promote proliferation, migration and angiogenesis in analogy to HDGF. Recombinant HDGFRP3 inhibited migration of endothelial cells in a modified Boyden chamber experiment, while cell survival was not affected. Nevertheless, the protein promoted angiogenesis in vitro, as assessed through vascular sprouting and tubulogenesis assays. Starting from the structural insight of the PWWP domain, an oligonucleotide-based inhibitor was designed and tested to block the pro-angiogenic effect of HDGFRP3. A single stranded DNA inhibited the pro-angiogenic properties of HDGFRP3 in vitro. After modifications to improve its serum stability, the cytotoxicity of the designed oligonucleotide-based molecule (BN210) was tested by an MTT cell viability assay on various NB cell lines. BN210 slightly reduced NB cells proliferation. To determine if BN210 could be used both as single anti-angiogenic agent and in combination with chemotherapy in vivo, orthotopic NB tumor-bearing mice were randomly divided in different groups of treatment: 1 mg/kg of vincristine (VCR), once a week for 4 weeks; 7-21 mg/kg of BN210, either i.p. (5 days/week) or i.v (every 2 days). Other mice were treated with a combination of VCR and BN210. NB-bearing mice treated with BN210 alone showed a partial increase in life span, compared to control mice. However, mice treated with the combination of VCR plus BN210 had statistically significant increased life span, compared to both the control and the single treatment groups, with long term survivors obtained with the combined schedule when BN210 was injected i.v. Thus, the oligonucleotide-based inhibition of the pro-angiogenic activity of HDGFRP3 can be considered as a novel strategy for combined anti-tumor therapy in NB. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5144. doi:10.1158/1538-7445.AM2011-5144

Prostate cancer (PCa) is a leading cause of death by cancer in men, resulting in approximately 32,000 deaths each year. While the cause of PCa is not clearly known at this time, some risk factors include age, diet, race, and activation of certain oncogenes. Hepatoma-derived growth factor (HDGF) is a recently discovered oncogene and a key mitogenic growth factor which is activated in lung, liver, and skin cancers, however, its role in the development of PCa is unknown. Therefore, the goal of this study is to characterize the role of HDGF in prostate carcinogenesis. A normal prostate cell line, RWPE-1, and four different PCa cell lines, LNCaP, 22RV1, DU145, and PC-3, were analyzed for their expression level of HDGF by western blot analysis. Results of this evaluation revealed that HDGF is over-expressed in multiple PCa cell lines while minimally expressed in RWPE-1 cells. When the HDGF gene is ectopically over-expressed in normal RWPE-1 cells, proliferative rate was increased by 1.5 fold compared to the normal cells, suggesting that HDGF has growth stimulating activity. On the contrary, down regulation of HDGF expression by siRNA significantly inhibited the survival of both androgen dependent (LNCaP) and androgen independent (PC-3) PCa cells. DNA content analysis of RWPE-1 cells stably expressing HDGF by flow cytometry showed that the majority of the cells were in the G2/M phase (55%) of the cell cycle while only 28% of the control RWPE-1 cells were at G2/M phase implying HDGF may have a mitotic function in prostate cells. Furthermore, AKT (phosphorylated form) and NFκB (p65 domain) signaling molecules were found to be activated in RWPE-1 cells expressing HDGF. This activation resulted in the increase of anti-apoptotic molecules Cyclin-E and BCL-2 and the simultaneous decrease in the pro-apoptotic molecule Bax. Activation of AKT-NFκB pathway plays a vital role in the carcinogenesis of several cancers, including PCa. Thus, HDGF over-expression may play a role in regulating this survival pathway in prostate carcinogenesis. Collectively, the results of this study suggest that HDGF is a key player in the development of PCa and may serve as a target for chemopreventive or chemotherapeutic strategies in PCa. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1109. doi:10.1158/1538-7445.AM2011-1109

HDGF was identified as an oncogene relevant for colon cancer carcinogenesis by cDNA-array analysis, RT-PCR and immunohistochemistry. The analysis were performed in colonic adenoma (Geki2), carcinoma (HT29) and metastasis (SW620) cell lines, and in 50 colorectal cancer tissues and corresponding normal mucosa. By incubation of the cell lines with the short chain fatty acid butyrate (4mM), it was possible to (down-) regulate the HDGF-expression level. In the patients we analysed, HDGF overexpression was not associated with a worse prognosis or any other clinical parameter. To study the mechanisms of action of HDGF we stably transfected a HDGF-siRNA containing plasmid into HT29 colon carcinoma cells, resulting in a almost complete inactivation of HDGF-expression. This blocking leads to altered growth characteristics and cell differentiation and the cells exhibit potent pro-apoptotic properties. An affymetrix-expression array was performed and first results will me shown at the meeting. In conclusion, HDGF might be a potential therapeutic target for human colorectal cancer and a modulation of expression is possible by the short chain fatty acid butyrate. These findings may have major implications in the treatment of colorectal cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2248. doi:10.1158/1538-7445.AM2011-2248