Hepatoma-derived growth factor involved in the carcinogenesis of gastric epithelial cells through promotion of cell proliferation by Erk1/2 activation

Heparin-binding growth factor (HDGF) drives radioresistance in breast cancer by activating the STAT3 signaling pathway

Although reports implicate radioresistance as an important obstacle for the management of breast cancer, its molecular mechanism is elusive. Herein, we found that high HDGF levels are expressed significantly in breast cancer and exhibit a positive association with poor survival prognosis. Heparin-binding growth factor (HDGF) was upregulated in radioresistant breast cancer cells, however, its knockdown could reduce breast cancer radioresistant both in vitro and in vivo. Additionally, the binding of RXRα to HDGF promoter blocked HDGF transcriptional activity, consequently inhibiting breast cancer radioresistance. The enhanced radioresistant activity of HDGF is induced by TKT and STAT3, impacting the STAT3-Tyr705 and STAT3-Ser727 phosphorylation and STAT3 transcriptional activity. Notably, HDGF depletion renders radioresistant hypersensitive to the drug that targets STAT3 phosphorylation. This article demonstrates the novel function of HDGF as a promising molecular target for predicting radioresistance in breast cancer.

A novel HDGF-ALCAM axis promotes the metastasis of Ewing sarcoma via regulating the GTPases signaling pathway

Ewing sarcoma (ES) is a type of highly aggressive pediatric tumor in bones and soft tissues and its metastatic spread remains the most powerful predictor of poor outcome. We previously identified that the transcription factor hepatoma-derived growth factor (HDGF) promotes ES tumorigenesis. However, the mechanisms underlying ES metastasis remain unclear. Here, we show that HDGF drives ES metastasis in vitro and in vivo, and HDGF reduces metastasis-free survival (MFS) in two independent large cohorts of human ES patients. Integrative analyses of HDGF ChIP-seq and gene expression profiling in ES cells reveal that HDGF regulates multiple metastasis-associated genes, among which activated leukocyte cell adhesion molecule (ALCAM) emerges as a major HDGF target and a novel metastasis-suppressor in ES. HDGF down-regulates ALCAM, induces expression and activation of the downstream effectors Rho-GTPase Rac1 and Cdc42, and promotes actin cytoskeleton remodeling and cell-matrix adhesion. In addition, repression of ALCAM and activation of Rac1 and Cdc42 are required for the pro-metastatic functions of HDGF in vitro. Moreover, analyses in murine models with ES tumor orthotopic implantation and experimental metastasis, as well as in human ES samples, demonstrate the associations among HDGF, ALCAM, and GTPases expression levels. Furthermore, high HDGF/low ALCAM expression define a subgroup of patients harboring the worst MFS. These findings suggest that the HDGF/ALCAM/GTPases axis represents a promising therapeutic target for limiting ES metastasis.

Downregulation of HDGF inhibits the tumorigenesis of bladder cancer cells by inactivating the PI3K-AKT signaling pathway

Background

Hepatoma-derived growth factor (HDGF) is a heparin-binding protein that has been observed to be abnormally expressed in numerous malignancies, but the definite role of HDGF in bladder cancer (BCa) has not been clarified. Here, we conduct the present study to evaluate correlations between HDGF and BCa.

Methods

Bioinformatics analysis was used to evaluate HDGF expression levels in BCa tissues. The effect of HDGF on cell proliferation, migration, invasion, cell cycle and apoptosis was analyzed utilizing CCK-8, clone formation, Transwell assays and flow cytometry, respectively. In addition, the xenograft tumor model was established.

Results

Based on bioinformatics analysis, we noticed that HDGF was highly expressed in BCa tissues and was positively correlated with poor prognosis in patients. Knockdown of HDGF markedly reduced tumorigenesis in BCa cells. Furthermore, the results of flow cytometry showed that HDGF deletion enhanced apoptosis in T24 and 253J cells and led to cell cycle arrest in G1 phase. In further studies, we found that tumor growth was inhibited in xenograft nude mouse models with HDGF deletion. The results of RNA-seq analysis revealed that the PI3K-AKT signaling pathway-related genes were obviously changed in HDGF-deficient 253J cells, and this result was further confirmed by Western blot analysis.

Conclusion

In summary, we suggest that HDGF plays a substantial role in BCa and promotes tumor development and progression by regulating the PI3K-AKT signaling pathway, which provides a promising target for BCa treatment.

Upregulation of miR‑95-3p inhibits growth of osteosarcoma by targeting HDGF

Osteosarcoma is the most common bone malignancy and miR-95-3p plays an important role in multiple cancers. The purpose of this study was to explore the effect and potential mechanism of miR-95-3p on the growth of osteosarcoma. In vitro, the osteosarcoma cell lines, SAOS-2 and U2OS cells, were transfected with miR-95-agomir to assess the role of miR-95-3p in proliferation and apoptosis of osteosarcoma cells. We determined that overexpression of miR-95-3p significantly attenuated cell proliferation but enhanced apoptosis in SAOS-2 and U2OS cells. We also found that overexpression of miR-95-3p in osteosarcoma cells downregulated the expression of hepatoma-derived growth factor (HDGF). Next, knockdown of HDGF by siRNA targeting HDGF clearly inhibited cell proliferation and induced apoptosis in U2OS cells. In vivo, a tumor formation assay in BALB/c nude mice was conducted by injecting the pre-miR-95 or control vector lentivirus-infected U2OS cells to determine the effect of miR-95-3p on the growth of osteosarcoma. Results showed miR-95-3p overexpression inhibited the osteosarcoma growth and downregulated the HDGF expression in xenografted tumor. For mechanism study, we co-transfected HDGF/pcDNA3.1 plasmid and miR-95-agomir to U2OS cells, and we demonstrated that overexpression of HDGF could attenuate the effects of miR-95-3p on U2OS cell proliferation, apoptosis and migration. These findings indicated that miR-95-3p might act as a potential tumor suppressor in osteosarcoma by targeting HDGF. Thus, miR-95-3p may become a potential therapeutic in treatment of osteosarcoma.

Helicobacter pylori Infection-Induced Hepatoma-Derived Growth Factor Regulates the Differentiation of Human Mesenchymal Stem Cells to Myofibroblast-Like Cells

Hepatoma-derived growth factor (HDGF) plays a critical role in tumor cell proliferation, anti-apoptosis, VEGF expression, lymph node metastasis and poor prognosis in human gastric cancer. Gastric cancer, as one of the most prevalent cancers worldwide, is the second leading cause of cancer-related mortality in the world for the prognosis of gastric cancer is generally poor, especially in patients with advanced stage. Helicobacter pylori (H. pylori) infection causes the chronic inflammation of stomach as well as the development of gastric cancer, with a three to six-fold increased risk of gastric cancer. Carcinoma-associated fibroblasts (CAFs) are myofibroblasts in tumor microenvironment, which possess various abilities to promote the progression of cancer by stimulating neoangiogenesis, proliferation, migration, invasion and therapy resistance of tumor cell. Mesenchymal stem cells (MSCs) are reported to promote tumor malignance through differentiation of MSCs toward CAFs. In the present study, we demonstrated that H. pylori infection promotes HDGF expression in human gastric cancer cells. HBMMSCs treated with HDGF assume properties of CAF-like myofibroblastic phenotypes, including expression of myofibroblast markers (α-smooth muscle actin (α-SMA), procollagen α1, tropomyoson I, desmin, fibroblast activation protein (FAP)), and fibroblast markers (prolyl-4-hydroxylase A1 (PHA1) and fibroblast specific protein-1 (FSP-1)/S100A4). HDGF recruits HBMMSCs, and then HBMMSCs further contributes to cell survival and invasive motility in human gastric cancer cells. Treatment of HDGF neutralizing antibody (HDGF-NAb) and serum significantly inhibit HDGF-regulated differentiation and recruitment of HBMMSCs. These findings suggest that HDGF might play a critical role in gastric cancer progress through stimulation of HBMMSCs differentiation to myofibroblast-like cells.

Hepatoma-derived growth factor functions as an unfavorable prognostic marker of human gliomas

Hepatoma-derived growth factor (HDGF) regulates various cellular processes involved in the onset and development of tumors. To evaluate the role of HDGF in human gliomas, western blotting analysis, immunohistochemistry staining and reverse transcription-quantitative polymerase chain reaction were performed to detect HDGF protein and mRNA expression levels in glioma and intractable epileptic brain tissue. Various clinicopathological characteristics, including age, gender, World health Organization grade, HDGF expression level, Karnofsky performance Status (KPS) and Ki-67 index were obtained from medical records. The correlation between HDGF expression and these clinicopathological characteristics was statistically evaluated. Following this, multivariate liner regression was used to evaluate their effect on patient survival time. HDGF expression, at the protein and mRNA levels, was observed to be more upregulated in glioma tissues compared with intractable epileptic brain tissue without tumor. Furthermore, the level of HDGF expression was positively associated with the grade of malignancy [grades II~IV, Ki-67 index ≥20% or KPS <80 (P<0.05)] and poor prognosis in glioma patients. Notably, the univariate survival analysis identified a negative correlation between HDGF-expression and survival time (P<0.01) and multivariate liner regression demonstrated that HDGF expression is an independent prognostic factor for gliomas (P=0.01). Overall, HDGF upregulation may be a crucial step in the development and invasion of glioma. Further survival analysis highlighted its prognostic value for this malignancy, implying its potential as a promising therapeutic target for gliomas.

Downregulated expression of hepatoma-derived growth factor inhibits migration and invasion of prostate cancer cells by suppressing epithelial-mesenchymal transition and MMP2, MMP9

Hepatoma-derived growth factor (HDGF) is commonly over-expressed and plays critical roles in the development and progression in a variety of cancers. It has previously been shown that HDGF is overregulated in prostate cancer cells compared to normal prostate cells, which is correlated with cellular migration and invasion of prostate cancer. Here, the molecular mechanisms of HDGF in prostate cancer is investigated. It is shown that HDGF knockdown reduces prostate cancer cellular migration and invasion in both androgen-sensitive LNCaP cells and androgen-insensitive DU145 and PC3 cells. Furthermore, Western blot analysis reveals that HDGF knockdown inhibits epithelial-mesenchymal transition (EMT) of prostate cancer cells by upregulation of protein E-cadherin and downregulation of proteins N-cadherin, Vimentin, Snail and Slug. In addition, mechanistic studies reveal that proteins MMP2 and MMP9 are down-regulated. In conclusion, our data suggested that HDGF knockdown inhibits cellular migration and invasion in vitro of prostate cancer via modulating epithelial-mesenchymal transition (EMT) signaling pathway, as well as MMP2 and MMP9 signaling pathway. These results supported that HDGF is a relevant protein in the progression of prostate cancer and may serve as a potentially therapeutic target for prostate cancer as well as its downstream targets.

The evaluation of hepatoma-derived growth factor in determining of prognosis and estimating of invasive probability of tumoral cells, recurrent, and metastasis of lymphatic glands in breast carcinoma

Introduction:

Recently, hepatoma-derived growth factor (HDGF) has been considered as a significantly important factor in determining the prognosis and estimating the probability of tumor cell invasions, recurrence, and lymph node metastasis in different cancers, including breast malignancies.

Materials and Methods:

Immunohistochemistry (IHC) study for HDGF was performed on paraffin-embedded blocks of patients with breast carcinoma in Modarres hospital, Tehran, Iran, since 1387–1390 (74 cases); three separate pathologists read the slides after complete IHC staining. Thereafter, necessary information was recorded from patient files, and eventually, findings were analyzed by SPSS program.

Results:

Expression of nuclear HDGF has significant statistical correlation with tumor grade according to Nottingham grading scheme; this correlation is also seen with nuclear pleomorphism of tumor cells and mitotic count. No correlation between age and tumor size with expression of HDGF is found. Lymph node metastasis is in inverse ratio to nuclear HDGF staining.

Conclusion:

Nuclear expression of HDGF in tumor cells is increased concordantly to tumor grade, which implies us to the role of this marker in determining the prognosis and choosing the most suitable treatment plan.

Atomic force microscopy characterization of kinase-mediated phosphorylation of a peptide monolayer

We describe the detailed microscopic changes in a peptide monolayer following kinase-mediated phosphorylation. A reversible electrochemical transformation was observed using square wave voltammetry (SWV) in the reversible cycle of peptide phosphorylation by ERK2 followed by dephosphorylation by alkaline phosphatase. A newly developed method for analyzing local roughness, measured by atomic force microscope (AFM), showed a bimodal distribution. This may indicate either a hole-formation mechanism and/or regions on the surface in which the peptide changed its conformation upon phosphorylation, resulting in increased roughness and current. Our results provide the mechanistic basis for developing biosensors for detecting kinase-mediated phosphorylation in disease.

Positive feedback loop of hepatoma-derived growth factor and β-catenin promotes carcinogenesis of colorectal cancer

To clarify the role of hepatoma-derived growth factor (HDGF) and β-catenin in carcinogenesis of colorectal cancer (CRC), our results showed that high HDGF expression was found in CRC cells and tissues and significantly related to histological differentiation (p = 0.035) and lymph node metastasis (p = 0.000). Significant positive correlation between HDGF expression and β-catenin abnormal expression was found in CRC tissues. High HDGF and lymph node metastasis were the strong independent prognostic indicators for reduced overall survival in CRC patients. HDGF knockdown dramatically inhibited cellular proliferation, migration, invasion, and tumorigenesis, both in vitro and in vivo, but induced G1 phase arrest and apoptosis in CRC cells. HDGF knock-down dramatically suppressed β-catenin and its down-stream genes expression in CRC cells. Intriguingly, β-catenin knock-down dramatically suppressed HDGF expression in CRC cells. Human recombinant Wnt3a and DKK1 treatment increased and decreased HDGF, β-catenin, c-Myc, cyclin D1, MMP9, and phos-GSK-3β (Ser9) protein expression in nuclear and cytoplasmic fraction of CRC cells upon β-catenin knock-down, respectively. Three HDGF-binding elements in β-catenin promoter were found and specific for transcriptional activation of β-catenin in CRC cells. In conclusion, our results first suggest that HDGF and β-catenin interacts as a positive feedback loop, which plays an important role in carcinogenesis and progression of CRC.

Hepatoma derived growth factor (HDGF) dynamics in ovarian cancer cells

As a leading cause of cancer death among women, identification of pathophysiologically-relevant biomarkers for ovarian cancer is important. The heparin binding, hepatoma-derived growth factor (HDGF) is overexpressed in ovarian cancer cell lines and may have prognostic value, but the mechanism by which this predominantly nuclear protein is secreted or functions is unknown. In this study, we focused on the circumstances under which HDGF is released by cells and the functional relevance of extracellular HDGF in the context of ovarian cancer. Immunofluorescence imaging showed nuclear localization of HDGF in ovarian cells, but unlike what is reported for other cell types, HDGF was minimally secreted into the media. However, HDGF was passively released by necrotic and late apoptotic cells. Extracellular HDGF was functionally relevant as it stimulated phosphorylation of ERK 1/2 and P38 in both non-cancer and ovarian cancer cells, and enhanced cellular migration. Overall, our study uncovers a novel function of HDGF as a messenger of cellular condition (alarmin) which in-turn modulates cellular function-aspects that could be used as a biomarker for ovarian cancer.

Transcriptomic changes associated with DKK4 overexpression in pancreatic cancer cells detected by RNA-Seq

The promotion of tumor development by Dickkopf 4 (DKK4) is receiving increased attention. However, the association between DKK4 and pancreatic cancer remains unclear. DKK4 expression was measured in pancreatic ductal adenocarcinoma tissues using qRT-PCR and immunohistochemistry. A DKK4-overexpressing pancreatic cancer cell line was established, and the differentially expressed genes (DEGs) that were induced by DKK4 were identified using transcriptome sequencing. The association between the identified DEGs and pancreatic cancer was assessed using gene ontology (GO), pathway analysis, pathway interaction networks, differentially expressed gene interaction network analysis, and co-expression gene networks. Finally, the accuracy of the analyses was validated using serial paraffin and frozen sections of clinical samples. DKK4 is highly expressed in pancreatic cancer tissues. DEGs of overexpression DKK4 of PANC-1 are mostly upregulated. GO and pathway analysis showed that DKK4 are associated with tumor and organ development and immune inflammation. The mitogen-activated protein kinase (MAPK) signaling pathway was the main signal transduction pathway that showed significant enrichment in overexpression DKK4 of PANC-1. The results of GO, pathway analyses, and differentially expressed gene interaction network identified genes that are closely associated with tumor development, including MAPK3, PIK3R3, VAV3, JAG1, and Notch3. The immunohistochemistry and immunofluorescence results suggested that DKK4 is co-expressed with MAPK3 and VAV3 in pancreatic cancer tissues. The results presented here show for the first time that DKK4 is highly expressed in pancreatic cancer tissues. Bioinformatics analysis of a DKK4-overexpressing of PANC-1 identified several oncogenes that are closely associated with tumors, and the MAPK signaling pathway is the core signal transduction pathway. DKK4 can be co-expressed with MAPK3 and VAV3 in pancreatic ductal adenocarcinoma tissues. Thus, DKK4 may have function on the development and progression of pancreatic cancer.

Prognostic role of hepatoma-derived growth factor in solid tumors of Eastern Asia: a systematic review and meta- analysis

Hepatoma-derived growth factor (HDGF) is a novel jack-of-all-trades in cancer. Here we quantify the prognostic impact of this biomarker and assess how consistent is its expression in solid tumors. A comprehensive search strategy was used to search relevant literature updated on October 3, 2014 in PubMed, EMBASE and WEB of Science. Correlations between HDGF expression and clinicopathological features or cancer prognosis was analyzed. All pooled HRs or ORs were derived from random-effects models. Twenty-six studies, primarily in Eastern Asia, covering 2,803 patients were included in the analysis, all of them published during the past decade. We found that HDGF overexpression was significantly associated with overall survival (OS) (HROS=2.35, 95%CI=2.04-2.71, p<0.001) and disease free survival (DFS) (HRDFS=2.25, 95%CI =1.81-2.79, p<0.001) in solid tumors, especially in non-small cell lung cancer, hepatocellular carcinoma and cholangiocarcinoma (CCA). Moreover, multivariate survival analysis showed that HDGF overexpression was an independent predictor of poor prognosis (HROS=2.41, 95%CI: 2.02-2.81, p<0.001; HRDFS=2.39, 95%CI: 1.77-3.24, p<0.001). In addition, HDGF overexpression was significantly associated with tumor category (T3-4 versus T1-2, OR=2.12, 95%CI: 1.17-3.83, p=0.013) and lymph node status (N+ versus N-, OR=2.37, 95%CI: 1.31-4.29, p=0.03) in CCA. This study provides a comprehensive examination of the literature available on the association of HDGF overexpression with OS, DFS and some clinicopathological features in solid tumors. Meta-analysis results provide evidence that HDGF may be a new indicator of poor cancer prognosis. Considering the limitations of the eligible studies, other large-scale prospective trials must be conducted to clarify the prognostic value of HDGF in predicting cancer survival.

HDGF: a novel jack-of-all-trades in cancer

HDGF is an important regulator of a broad range of cancer cell activities and plays important roles in cancer cell transformation, apoptosis, angiogenesis and metastasis. Such a divergent influence of HDGF on cancer cell activities derives from its multiple inter- and sub-cellular localizations where it interacts with a range of different binding partners. Interestingly, high levels of HDGF could be detected in patients' serum of some cancers. This review is focused on the role of HDGF in tumorigenesis and metastasis, and provides insight for application in clinical cancer therapy as well as its clinical implications as a prognostic marker in cancer progression.

Integrating proteomics with electrochemistry for identifying kinase biomarkers

We present an integrated approach for highly sensitive identification and validation of substrate-specific kinases as cancer biomarkers. Our approach combines phosphoproteomics for high throughput cancer-related biomarker discovery from patient tissues and an impedimetric kinase activity biosensor for sensitive validation. Using non-small-cell lung cancer (NSCLC) as a proof-of-concept study, label-free quantitative phosphoproteomic analysis of a pair of cancerous and its adjacent normal tissues revealed 198 phosphoproteins that are over-phosphorylated in NSCLC. Among the differentially regulated phosphorylation sites, the most significant alteration was in residue S165 in the Hepatoma Derived Growth Factor (HDGF) protein. Hence, HDGF was selected as a model system for the electrochemical studies. Further motif-based analysis of this altered phosphorylation site revealed that extracellular-signal-regulated kinase 1/2 (ERK1/2) are most likely to be the corresponding kinases. For validation of the kinase-substrate pair, densely packed peptide monolayers corresponding to the HDGF phosphorylation site were coupled to a gold electrode. Phosphorylation of the monolayer by ERK2 and dephosphorylation by alkaline phosphatase (AP) were detected by electrochemical impedance spectroscopy (EIS) and surface roughness analysis. Compared to other methods for quantification of kinase concentration, this label-free electrochemical assay offers the advantages of ultra-sensitivity as well as higher specificity for the detection of cancer-related kinase-substrate pair. With implementation of multiple kinase-substrate biomarker pairs, we expect this integrated approach to become a high throughput platform for discovery and validation of phosphorylation-mediated biomarkers.

Hepatoma-Derived Growth Factor: Its Possible Involvement in the Progression of Hepatocellular Carcinoma

The development of hepatocellular carcinoma (HCC) is an important complication of viral infection induced by hepatitis virus C, and our major research theme is to identify a new growth factor related to the progression of HCC. HDGF (hepatoma-derived growth factor) is a novel growth factor that belongs to a new gene family. HDGF was initially purified from the conditioned medium of a hepatoma cell line. HDGF promotes cellular proliferation as a DNA binding nuclear factor and a secreted protein acting via a receptor-mediated pathway. HDGF is a unique multi-functional protein that can function as a growth factor, angiogenic factor and anti-apoptotic factor and it participates in the development and progression of various malignant diseases. The expression level of HDGF may be an independent prognostic factor for predicting the disease-free and overall survival in patients with various malignancies, including HCC. Furthermore, the overexpression of HDGF promotes the proliferation of HCC cells, while a reduction in the HDGF expression inhibits the proliferation of HCC cells. This article provides an overview of the characteristics of HDGF and describes the potential role of HDGF as a growth-promoting factor for HCC.

Downregulation of the expression of HDGF attenuates malignant biological behaviors of hilar cholangiocarcinoma cells

Hepatoma-derived growth factor (HDGF) has been reported to be a potential predictive and prognostic marker for several types of cancer and important in malignant biological behaviors. However, its role in human hilar cholangiocarcinoma remains to be elucidated. Our previous study demonstrated that high expression levels of HDGF in hilar cholangiocarcinoma tissues correlates with tumor progression and patient outcome. The present study aimed to elucidate the detailed functions of the HDGF protein. This was performed by downregulating the protein expression of HDGF in the FRH0201 hilar cholangiocarcinoma cell line by RNA interference (RNAi) in vitro, and revealed that downregulation of the HDGF protein significantly inhibited the malignant biological behavior of the FRH0201 cells. In addition, further investigation revealed that downregulation of the protein expression of HDGF significantly decreased the secretion of vascular endothelial growth factor, which may be the mechanism partially responsible for the inhibition of malignant biological behaviors. These findings demonstrated that HDGF is important in promoting malignant biological behaviors, including proliferation, migration and invasion of hilar cholangiocarcinoma FRH0201 cells. Inhibition of the expression of HDGF downregulated the malignant biological behaviors, suggesting that downregulation of the protein expression of HDGF by RNAi may be a novel therapeutic approach to inhibit the progression of hilar cholangiocarcinoma.

Hepatoma-derived growth factor: from the bovine uterus to the in vitro embryo culture

Early in cow embryo development, hepatoma-derived growth factor (HDGF) is detectable in uterine fluid. The origin of HDGF in maternal tissues is unknown, as is the effect of the induction on developing embryos. Herein, we analyze HDGF expression in day 8 endometrium exposed to embryos, as well as the effects of recombinant HDGF (rHDGF) on embryo growth. Exposure to embryos did not alter endometrial levels of HDGF mRNA or protein. HDGF protein localized to cell nuclei in the luminal epithelium and superficial glands and to the apical cytoplasm in deep glands. After uterine passage, levels of embryonic HDGF mRNA decreased and HDGF protein was detected only in the trophectoderm. In fetal fibroblast cultures, addition of rHDGF promoted cell proliferation. In experiments with group cultures of morulae in protein-free medium containing polyvinyl alcohol, adding rHDGF inhibited blastocyst development and did not affect cell counts when the morulae were early (day 5), whereas it enhanced blastocyst development and increased cell counts when the morulae were compact (day 6). In cultures of individual day 6 morulae, adding rHDGF promoted blastocyst development and increased cell counts. Our experiments with rHDGF indicate that the growth factor stimulates embryonic development and cell proliferation. HDGF is synthesized similarly by the endometrium and embryo, and it may exert embryotropic effects by autocrine and/or paracrine mechanisms.

Diterpenoid C of Radix Curcumae: an inhibitor of proliferation and inducer of apoptosis in human colon adenocarcinoma cells acting via inhibiting MAPK signaling pathway

CONTEXT

Radix Curcumae is a traditional Chinese medicine that possesses antitumor properties, from which a new compound, diterpenoid C, was previously isolated and characterized.

OBJECTIVE

In this study, using human colon adenocarcinoma SW620 cells, we further investigated the antitumor effects of diterpenoid C and the underlying mechanisms.

MATERIALS AND METHODS

Cell proliferation was assessed with the MTT assay. Cell apoptosis and cell-cycle progression were analyzed with flow cytometry. The expression of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (p38 MAPK), and their phosphorylated forms, as well as caspase-3 protein levels were examined with Western blots.

RESULTS

Diterpenoid C could inhibit the proliferation of SW620 cells in a dose- and time-dependent manner. The median inhibitory concentration (IC50) at 24, 48, and 72 h were 28.31, 15.58, and 6.14 μg/ml, respectively. The inhibition of proliferation was found to be statistically significant as compared with the well-established drugs 5-fluorouracil (5-Fu) and oxaliplatin (L-OHP) (p < 0.01). Diterpenoid C also induced apoptosis and arrested cell cycle. It showed the highest apoptosis rate (98.20 ± 0.91%) at 70 μg/ml, at 72 h. Meanwhile, diterpenoid C suppressed the phosphorylation of ERK, JNK, and p38 MAPK proteins, and markedly induced the cleavage of caspase 3.

DISCUSSION AND CONCLUSION

Diterpenoid C inhibits proliferation and induces apoptosis of cancer cells by suppressing the MAPK signaling pathway and inducing apoptotic factor caspase-3. Our results suggest that this novel compound might become a potent chemotherapeutic agent for the treatment of colon cancer and further studies are warranted.

Prognostic significance of nuclear hepatoma-derived growth factor expression in gallbladder cancer

AIM: To assess the expression of nuclear hepatoma-derived growth factor (HDGF) in benign and malignant gallbladder lesions and to determine its clinicopathological significance.

METHODS: We studied 40 patients with gallbladder cancer (GBC) and a control group of 40 patients with cholelithiasis. All diagnoses of GBC and cholelithiasis were confirmed by histopathological examination after surgery. None of the patients received chemotherapy or radiotherapy before surgery. All tissue samples were fixed in 4% formalin immediately after removal and embedded in paraffin for immunohistochemical staining. The HDGF expression in the GBC and cholelithiasis specimens was examined by immunohistochemical staining. The relationship between the HDGF expression and the clinicopathological parameters of GBC was analyzed.

RESULTS: Nuclear HDGF expression was significantly higher (77.5%) in GBC than in chronic cholelithiasis (21.5%, P < 0.001). High nuclear HDGF levels were associated with histopathological subtype (P < 0.05), clinical stage (P < 0.01), and perineural invasion (P < 0.01) but not with sex, age, history of gallstones, or lymph node metastasis. A univariate Kaplan-Meier analysis showed that positive nuclear HDGF expression was associated with decreased overall survival (P < 0.01). Multivariate Cox regression analysis showed that nuclear HDGF expression and lymph node metastasis were independent risk factors for disease-free survival.

CONCLUSION: The expression of nuclear HDGF might be closely related to the carcinogenesis, clinical biological behaviors, and prognosis of gallbladder adenocarcinoma.

Alterations in the rat serum proteome induced by prepubertal exposure to bisphenol a and genistein

Humans are exposed to an array of chemicals via the food, drink and air, including a significant number that can mimic endogenous hormones. One such chemical is Bisphenol A (BPA), a synthetic chemical that has been shown to cause developmental alterations and to predispose for mammary cancer in rodent models. In contrast, the phytochemical genistein has been reported to suppress chemically induced mammary cancer in rodents, and Asians ingesting a diet high in soy containing genistein have lower incidence of breast and prostate cancers. In this study, we sought to: (1) identify protein biomarkers of susceptibility from blood sera of rats exposed prepubertally to BPA or genistein using Isobaric Tandem Mass Tags quantitative mass spectrometry (TMT-MS) combined with MudPIT technology and, (2) explore the relevance of these proteins to carcinogenesis. Prepubertal exposures to BPA and genistein resulted in altered expression of 63 and 28 proteins in rat sera at postnatal day (PND) 21, and of 9 and 18 proteins in sera at PND35, respectively. This study demonstrates the value of using quantitative proteomic techniques to explore the effect of chemical exposure on the rat serum proteome and its potential for unraveling cellular targets altered by BPA and genistein involved in carcinogenesis.

miR-141 suppresses proliferation and motility of gastric cancer cells by targeting HDGF

miR-141 belongs to the miR-200 family, and has been found to be associated with numerous human malignancies; however, its role in gastric cancer (GC) has not been examined in detail. Here, we validated that miR-141 was decreased in GC tissues and cell lines. Forced expression of miR-141 significantly repressed GC cell proliferation and colony formation. Furthermore, miR-141 suppressed in vitro migration and invasion of GC cells. Hepatoma-derived growth factor (HDGF) was confirmed to be a direct target of miR-141 in GC cells. The suppressive effects of miR-141 on GC cell proliferation, colony formation, in vitro migration, and invasion were partially mediated by suppressing HDGF expression. Moreover, the expression of HDGF was negatively correlated with miR-141 in GC tissues. Our data suggest that miR-141 might be associated and plays essential role in GC progression.

Upregulation of nucleus HDGF predicts poor prognostic outcome in patients with penile squamous cell carcinoma bypass VEGF-A and Ki-67

Hepatoma-derived growth factor (HDGF) has been verified to serve as a credible prognostic marker for several types of cancers, but its role in urologic carcinomas remains undetermined. In this study, we analyzed the significance of HDGF, as well as its relative factors such as vascular endothelial growth factor-A (VEGF-A) and Ki-67, in penile squamous cell carcinoma (PSCC). Formalin-fixed paraffin-embedded PSCC samples from 54 patients receiving surgery at Qilu Hospital of Shandong University were included in the retrospective study. The expressions of HDGF, VEGF-A, and Ki-67 were detected by immunohistochemistry of a non-biotin polymerized horseradish peroxidase method. The relationships between the expressions of HDGF and VEGF-A, Ki-67 were assessed. Moreover, their correlations with clinical pathologic characteristics and disease prognosis were, respectively, evaluated. HDGF, VEGF-A, and Ki-67 were positively expressed in 28 (51.9%), 29 (53.7%), and 26 (48.1%) patients, respectively. The expressions of VEGF-A and Ki-67 were closely correlated with PSCC type (P < 0.05). A statistically significant relationship between the expressions of HDGF and VEGF-A in PSCC was observed (P = 0.03). Patients with symptom interval of more than 6 months had a significantly poorer survival rate than those with symptom interval less than 6 months (43.3 vs. 70.8%, P = 0.043). Patients with positive HDGF expression also showed a significantly poorer survival rate than those with negative HDGF expression (39.3 vs. 73.1%, P = 0.013). Logistic regression demonstrated that the expression level of HDGF was an independent predictor for the prognosis of postoperative patients. The expression of HDGF significantly correlated with VEGF-A, but not Ki-67 expression. Overexpression of HDGF, rather than VEGF-A or Ki-67, was confirmed to be an independent prognosticator of poor outcome for PSCC patients.

The expression of TMPRSS4 and Erk1 correlates with metastasis and poor prognosis in Chinese patients with gastric cancer

Purpose

The present study investigated the clinical significance of transmembrane protease, serine 4(TMPRSS4) and extracellular signal-regulated kinases 1 (Erk1) in the development, progression and metastasis of gastric cancer.

Methods

Immunohistochemistry was employed to analyze TMPRSS4 and Erk1 expression in 436 gastric cancer cases and 92 non-cancerous human gastric tissues.

Results

Protein levels of TMPRSS4 and Erk1 were up-regulated in gastric cancer lesions compared with adjacent noncancerous tissues. High expression of TMPRSS4 correlated with age, size, Lauren’s classification, depth of invasion, lymph node and distant metastases, regional lymph node stage and TNM stage, and also with expression of Erk1. In stages I, II and III, the 5-year survival rate of patients with high TMPRSS4 expression was significantly lower than in patients with low expression. Further multivariate analysis suggests that up-regulation of TMPRSS4 and Erk1 were independent prognostic indicators for the disease, along with depth of invasion, lymph node and distant metastasis and TNM stage.

Conclusions

Expression of TMPRSS4 in gastric cancer is significantly associated with lymph node and distant metastasis, high Erk1 expression, and poor prognosis. TMPRSS4 and Erk1 proteins could be useful markers to predict tumor progression and prognosis of gastric cancer.

Downregulated expression of hepatoma-derived growth factor (HDGF) reduces gallbladder cancer cell proliferation and invasion

Hepatoma-derived growth factor (HDGF), a heparin-binding growth factor, has a wide range of biological functions, including mitogenic activity and vascular development. Recent studies demonstrated that HDGF also acted as an oncogene with aberrantly increased activity in multiple human cancers; however, little is known about the biological function of HDGF in gallbladder cancer (GBC). In this study, we focused on the clinical significance and biological functions of HDGF in GBC and found that Nuclear HDGF protein overexpression was frequently detected in GBC tissues. Patients with nuclear HDGF-positive tumors had worse overall survival than patients with HDGF-negative tumors. Furthermore, treatment of GBC lines with HDGF-targeting siRNA oligonucleotides (HDGF-siRNA) significantly reduced the proliferation of GBC-SD and SGC-996 cell lines and diminished both anchorage-independent growth on soft agar and cell migration. These data indicate that HDGF acts as a putative oncogene in GBC and could be a novel diagnostic and therapeutic target for GBC.

Hepatoma-derived growth factor and nucleolin exist in the same ribonucleoprotein complex

BACKGROUND

Hepatoma-derived growth factor (HDGF) is a protein which is highly expressed in a variety of tumours. HDGF has mitogenic, angiogenic, neurotrophic and antiapoptotic activity but the molecular mechanisms by which it exerts these activities are largely unknown nor has its biological function in tumours been elucidated. Mass spectrometry was performed to analyse the HDGFStrep-tag interactome. By Pull-down-experiments using different protein and nucleic acid constructs the interaction of HDGF and nucleolin was investigated further.

RESULTS

A number of HDGFStrep-tag copurifying proteins were identified which interact with RNA or are involved in the cellular DNA repair machinery. The most abundant protein, however, copurifying with HDGF in this approach was nucleolin. Therefore we focus on the characterization of the interaction of HDGF and nucleolin in this study. We show that expression of a cytosolic variant of HDGF causes a redistribution of nucleolin into the cytoplasm. Furthermore, formation of HDGF/nucleolin complexes depends on bcl-2 mRNA. Overexpression of full length bcl-2 mRNA increases the number of HDGF/nucleolin complexes whereas expression of only the bcl-2 coding sequence abolishes interaction completely. Further examination reveals that the coding sequence of bcl-2 mRNA together with either the 5' or 3' UTR is sufficient for formation of HDGF/nucleolin complexes. When bcl-2 coding sequence within the full length cDNA is replaced by a sequence coding for secretory alkaline phosphatase complex formation is not enhanced.

CONCLUSION

The results provide evidence for the existence of HDGF and nucleolin containing nucleoprotein complexes which formation depends on the presence of specific mRNAs. The nature of these RNAs and other components of the complexes should be investigated in future.

JNK suppression is essential for 17β-Estradiol inhibits prostaglandin E2-Induced uPA and MMP-9 expressions and cell migration in human LoVo colon cancer cells

Background

Epidemiological studies demonstrate that the incidence and mortality rates of colorectal cancer in women are lower than in men. However, it is unknown if 17β-estradiol treatment is sufficient to inhibit prostaglandin E2 (PGE2)-induced cellular motility in human colon cancer cells.

Methods

We analyzed the protein expression of urokinase plasminogen activator (uPA), tissue plasminogen activator (tPA), matrix metallopeptidases (MMPs), plasminogen activator inhibitor-1 (PAI-1) and tissue inhibitor of metalloproteinases (TIMPs), and the cellular motility in PGE2-stimulated human LoVo cells. 17β-Estradiol and the inhibitors including LY294002 (Akt activation inhibitor), U0126 (ERK1/2 inhibitor), SB203580 (p38 MAPK inhibitor), SP600125 (JNK1/2 inhibitor), QNZ (NFκB inhibitor) and ICI 182 780 were further used to explore the inhibitory effects of 17β-estradiol on PGE2-induced LoVo cell motility. Student's t-test was used to analyze the difference between the two groups.

Results

Upregulation of urokinase plasminogen activator (uPA), tissue plasminogen activator (tPA) and matrix metallopeptidases (MMPs) is reported to associate with the development of cancer cell mobility, metastasis, and subsequent malignant tumor. After administration of inhibitors including LY294002, U0126, SB203580, SP600125 or QNZ, we found that PGE2 treatment up-regulated uPA and MMP-9 expression via JNK1/2 signaling pathway, thus promoting cellular motility in human LoVo cancer cells. However, PGE2 treatment showed no effects on regulating expression of tPA, MMP-2, plasminogen activator inhibitor-1 (PAI-1), tissue inhibitor of metalloproteinase-1, -2, -3 and -4 (TIMP-1, -2, -3 and -4). We further observed that 17β-estradiol treatment inhibited PGE2-induced uPA, MMP-9 and cellular motility by suppressing activation of JNK1/2 in human LoVo cancer cells.

Conclusions

Collectively, these results suggest that 17β-estradiol treatment significantly inhibits PGE2-induced motility of human LoVo colon cancer cells.

[Aberrant expression of HDGF and its prognostic values in surgically resected non-small cell lung cancer]

BACKGROUND AND OBJECTIVE

Our previous studies revealed that hepatoma-derived growth factor (HDGF) is highly expressed in non-small cell lung cancer (NSCLC) cells, playing important roles in promoting NSCLC cells growth and invasion. The aim of this study is to detect the expression of HDGF in 158 cases of surgically resected NSCLC and evaluate its clinical significance.

METHODS

Immunohistochemical SP method was used to detect the expression of HDGF in 158 NSCLC tissues and 12 normal control lung tissues. Survival analysis was further conducted.

RESULTS

HDGF was found significantly highly expressed in 158 NSCLC tissues compared with normal control lung tissues (P < 0.001). The 5-year survival rate was 38.2% in HDGF high expression cases, compared with 63.1% in HDGF low expression cases, the difference was statistically significant (P=0.009). Linear correlation analysis discovered a significantly negative correlation between HDGF expression and the survival time (r=-0.183, P=0.022). COX proportion hazard model analysis revealed that pathological stages and HDGF expression were independent prognostic factors for this group of 158 resected NSCLC cases.

CONCLUSIONS

HDGF is highly expressed in human NSCLC tissues, predicting worse prognosis in resected NSCLCs. It might be useful molecular biomarker for predicting the prognosis of resected NSCLCs.

Cell surface heparan sulfates mediate internalization of the PWWP/HATH domain of HDGF via macropinocytosis to fine-tune cell signalling processes involved in fibroblast cell migration

HDGF (hepatoma-derived growth factor) stimulates cell proliferation by functioning on both sides of the plasma membrane as a ligand for membrane receptor binding to trigger cell signalling and as a stimulator for DNA synthesis in the nucleus. Although HDGF was initially identified as a secretory heparin-binding protein, the biological significance of its heparin-binding ability remains to be determined. In the present study we demonstrate that cells devoid of surface HS (heparan sulfate) were unable to internalize HDGF, HATH (N-terminal domain of HDGF consisting of amino acid residues 1-100, including the PWWP motif) and HATH(K96A) (single-site mutant form of HATH devoid of receptor binding activity), suggesting that the binding of HATH to surface HS is important for HDGF internalization. We further demonstrate that both HATH and HATH(K96A) could be internalized through macropinocytosis after binding to the cell surface HS. Interestingly, HS-mediated HATH(K96A) internalization is found to exhibit an inhibitory effect on cell migration and proliferation in contrast with that observed for HATH action on NIH 3T3 cells, suggesting that HDGF exploits the innate properties of both cell surface HS and membrane receptor via the HATH domain to affect related cell signalling processes. The present study indicates that MAPK (mitogen-activated protein kinase) signalling pathways could be affected by the HS-mediated HATH internalization to regulate cell migration in NIH 3T3 fibroblasts, as judged from the differential effect of HATH and HATH(K96A) treatment on the expression level of matrix metalloproteases.

Secretion of hepatoma-derived growth factor is regulated by N-terminal processing

Hepatoma-derived growth factor (HDGF) was first purified as a growth factor secreted by hepatoma cells. It promotes angiogenesis and has been related to tumorigenesis. To date, little is known about the molecular mechanisms of HDGF functions and especially its routes or regulation of secretion. Here we show that secretion of HDGF requires the N-terminal 10 amino acids and that this peptide can mediate secretion of other proteins, such as enhanced green fluorescent protein, if fused to their N-terminus. Our results further demonstrate that cysteine residues at positions 12 and 108 are linked via an intramolecular disulfide bridge. Surprisingly, phosphorylation of serine 165 in the C-terminal part of HDGF plays a critical role in the secretion process. If this serine is replaced by alanine, the N-terminus is truncated, the intramolecular disulfide bridge is not formed and the protein is not secreted. In summary, these observations provide a model of how phosphorylation, a disulfide bridge and proteolytic cleavage are involved in HDGF secretion.

Overexpressed HDGF as an independent prognostic factor is involved in poor prognosis in Chinese patients with liver cancer

BACKGROUND

Hepatoma-derived growth factor (HDGF) is involved in the hepatocarcinogenesis. In this study, we investigated the HDGF expression in hepatocellular carcinoma (HCC) and its correlation with clinicopathologic features, including the survival of patients with HCC. Furthermore, we examined the biological processes regulated by HDGF during the development of using HepG2 cell line as a model system.

METHODS

We used immunohistochemistry to compare HDGF protein expression in HCC and normal liver tissues and further analyze the HDGF protein expression in clinicopathologically characterized 137 HCC cases. We stably knocked down the endogenous expression level of HDGF in HepG2 cells with specific shRNA-expressing lentiviral vector. Following the successful establishment of stable cells, we examined in vitro cell growth by MTT assay, anchorage-independent growth by soft-agar colony formation assay and cell migration/invasion by transwell and boyden chamber assay. And in addition, we also investigated the in vivo tumor growth by xenograft transplantation of HepG2 cells into nude mice.

RESULTS

Protein expression level of HDGF was markedly higher in HCC tissues than that in the normal liver tissues(P = 0.011). In addition, high expression of HDGF protein was positively correlated with T classification(p < 0.001), N classification (p < 0.001), and clinical stage (p < 0.001) of HCC patients. Patients with higher HDGF expression showed a significantly shorter overall survival time than did patients with low HDGF expression. Multivariate analysis suggested that HDGF expression might be an independent prognostic indicator(p < 0.001) for the survival of patients with HCC. HDGF-specific shRNA (shHDGF) successfully knocked down its endogenous expression in HepG2 cells. Compared to the parental and control shRNA-transfected (shCtrl) HepG2 cells, the shHDGF cells exhibited significantly reduced in vitro cell growth, anchorage-independent growth, cell migration and invasion (p < 0.05). In vivo, the xenograft transplants from shHDGF cells gave rise to much smaller tumors as compared to those from shCtrl cells.

CONCLUSION

High HDGF expression is associated with poor overall survival in patients with HCC. Down-regulation of HDGF inhibits the growth, anchorage-independent growth, migration and invasion of HepG2 cells.

Significance of HDGF expression in hepatocellular carcinoma tissue and HepG2 cells

AIM: To investigate the expression of hepatoma-derived growth factor (HDGF) in hepatocellular carcinoma (HCC) tissue and HepG2 cells and to analyze its significance.

METHODS: Ten HCC tissue samples and matched noncancerous tissue samples were collected. The mRNA expression of HDGF in these HCC samples, noncancerous tissue samples and HepG2 cells was detected by real-time RT-PCR. The protein expression of HDGF in 137 HCC tissue samples and 49 normal liver tissue samples was examined by immunohistochemistry. The relationship between HDGF expression and clinicopathological parameters in HCC was then analyzed.

RESULTS: The expression levels of HDGF mRNA were 21.11 and 11.39 times higher in HCC tissue and HepG2 cells than in noncancerous tissue, respectively. The positive rate of HDGF expression in HCC tissue was significantly higher than that in normal liver tissue (77.4% vs 51.5%, P = 0.011). High expression of HDGF protein was positively correlated with T classification, N classification and clinical stage (all P < 0.05) in HCC patients. Univariate Cox analysis showed that HDGF expression, N classification and clinical stage had significant correlation with survival prognosis of HCC patients (P = 0.028, 0.041 and 0.000; HR = 1.557, 1.526 and 2.316, respectively). Multivariate analysis showed that HDGF expression might be an independent prognostic indicator (P = 0.000, HR = 0.358) for the development and progression of HCC. Patients with higher HDGF expression showed a significantly shorter overall survival time than those with low HDGF expression.

CONCLUSION: HDGF is highly expressed in HCC tissue and HepG2 cells. High HDGF expression is an independent prognostic factor in HCC patients. High HDGF expression is associated with poor overall survival in patients with HCC.

17beta-estradiol inhibits prostaglandin E2-induced COX-2 expressions and cell migration by suppressing Akt and ERK1/2 signaling pathways in human LoVo colon cancer cells

Epidemiological studies demonstrate that the incidence and mortality rates of colorectal cancer in women are lower than in men. However, it is unknown if 17beta-estradiol treatment is sufficient to inhibit prostaglandin E2 (PGE2)-induced cellular motility in human colon cancer cells. Upregulation of cyclooxygenase-2 (COX-2) is reported to associate with the development of cancer cell mobility, metastasis, and subsequent malignant tumor. After administration of inhibitors including LY294002 (Akt activation inhibitor), U0126 (ERK1/2 inhibitor), SB203580 (p38 MAPK inhibitor), SP600125 (JNK1/2 inhibitor), or QNZ (NFkappaB inhibitor), we found that PGE2 treatment increases COX-2 via Akt and ERK1/2 pathways, thus promoting cellular motility in human LoVo cancer cells. We further observed that 17beta-estradiol treatment inhibits PGE2-induced COX-2 expression and cellular motility via suppressing activation of Akt and ERK1/2 in human LoVo cancer cells. Collectively, these results suggest that 17beta-estradiol treatment dramatically inhibits PGE2-induced progression of human LoVo colon cancer cells.

Mild intellectual disability associated with a progeny of father-daughter incest: genetic and environmental considerations

We report the case of a 34-year-old female resulting from a father-daughter sexual abuse and presenting a phenotype of mild intellectual disability with minor dysmorphic features. Karyotyping showed a normal 46, XX constitution. Array-based comparative genomic hybridization (array-CGH) revealed a heterozygote 320kb 6p22.3 microdeletion in the proband, encompassing only one known gene, and therefore unlikely to be the cause of the phenotype. However, the role of other genetic factors, such as a recessive condition, could not be ruled out as a putative cause for the phenotype. On the other hand, the role played by a heavily detrimental familial situation on the development and outcome, and possibly leading or contributing to a mild intellectual disability, should be taken into account.

shRNA targeting HDGF suppressed cell growth and invasion of squamous cell lung cancer

Hepatoma-derived growth factor (HDGF), a nuclear protein with both mitogenic and angiogenic activity, has been reported to be mainly involved in tumorigenesis and the progression of non-small cell lung cancer. In this study, the HDGF expression was knocked down by specific-shRNA with lentivirus expression vector targeting HDGF in lung squamous cell carcinoma 520 cells. HDGF knocked down by shRNA suppressed the cell proliferation significantly both in vitro and in vivo as indicated by MTT, plate clone and transplanted tumor model assays. In addition, the knocked-down expression of HDGF also inhibited cell migration and invasion as shown in transwell and Boyden experiments. We concluded that HDGF acts as an oncogene participating in the pathogenesis of squamous cell lung cancer, and HDGF may be a key therapeutic target for non-small cell lung cancer.

Apoptosis of human colorectal carcinoma cells is induced by blocking hepatoma-derived growth factor

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 and its role in keloid pathogenesis

Hepatoma-derived growth factor (HDGF) is a novel mitogenic growth factor that has been implicated in many different carcinomas. Its role in keloid biology has not yet been investigated. The present study is aimed at examining the role of HDGF in keloid pathogenesis. Immunohistochemical staining and Western blot analyses were used to examine in vivo localization and expression of HDGF in keloid and normal skin tissue. This was followed by the detection of HDGF expression in fibroblasts cultured in vitro and fibroblasts exposed to serum. To investigate the effect of epithelial–mesenchymal interactions, a two-chamber system was employed in which keratinocytes on membrane inserts were co-cultured with the fibroblasts. HDGF expression levels in all cell extracts and conditioned media were assayed through Western blot analysis. In another set of experiments, the effect of exogenous recombinant HDGF on keloid fibroblasts (KF) and normal fibroblasts (NF) was examined. Cell proliferation was assessed by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and by quantifying proliferating cell nuclear antigen (PCNA) expression. Downstream targets of HDGF were identified by detecting their expression through Western blot analysis. Our results indicate that there was an increase in HDGF expression in the dermis of keloid compared with normal skin tissue. The application of serum and epithelial–mesenchymal interactions did not seem to have any effect on intracellular HDGF expression levels. However, co-culturing keloid keratinocytes with KFs resulted in increased HDGF secretion when compared with monoculture or normal controls. Furthermore, treatment with exogenous recombinant HDGF was found to increase the proliferation of KFs, activate the extracellular signal-regulated kinase (ERK) pathway and up-regulate the secretion of vascular endothelial growth factor (VEGF).