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

Taurine alleviates colitis by regulating oxidative stress, inflammatory responses, ER stress, and apoptotic pathways

Colitis is an inflammatory condition affecting the colon, characterized by oxidative stress, ER stress, and apoptosis, which leads to severe tissue damage. Existing treatments are associated with significant side effects, necessitating the exploration of alternative therapeutic agents. Taurine is a commonly consumed bioactive sulfur-containing amino acid, recognized for its cyto-protective property. In this study, we are using a male Wistar rat model for 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis and treated them with taurine. Colitis development was indicated by repeated loose bloody stools, reduced appetite, and weight loss. Macroscopic examination revealed an inflamed colon surface with ulcerations, while histopathology showed a destroyed crypt structure and damage to the epithelial and mucosal layers in the colitis-affected rats. However, taurine administration reverses such adverse effects of colitis. Taurine significantly mitigates the oxidative stress by upregulating the level of anti-oxidant molecules, such as CAT, GST and SOD, which were significantly down-regulated in colitis. In addition, increased levels of inflammatory molecules (TNF-α, IL- 1β, IL- 6, MCP- 1, ICAM- 1, and VCAM- 1) in colitis were reduced by taurine supplementation. Furthermore, we observed taurine alleviates colitis induced up-regulation of important endoplasmic reticulum (ER) stress markers like, CHOP, GRP78, calpain 1, and caspase 12. We have also demonstrated that taurine supplementation reverses colitis induced apoptosis by assessing the modulation of apoptotic markers (Bax, Bcl- 2, caspase 9 and caspase 3). Furthermore, no instances of toxicity from taurine were observed. Thus, taurine shows a potential to be utilized as a therapeutic agent for colitis with further detailed investigation.

Hypoxia induced deregulation of sphingolipids in colon cancer is a prognostic marker for patient outcome

Sphingolipids are important for the physicochemical properties of cellular membranes and deregulated in tumors. In human colon cancer tissue ceramide synthase (CerS) 4 and CerS5 are reduced which correlates with a reduced survival probability of late-stage colon cancer patients. Both enzymes are reduced after hypoxia in advanced colorectal cancer (CRC) cells (HCT-116, SW620) but not in non-metastatic CRC cells (SW480, Caco-2). Downregulation of CerS4 or CerS5 in advanced CRC cells enhanced tumor formation in nude mice and organoid growth in vitro. This was accompanied by an enhanced proliferation rate and metabolic changes leading to a shift towards the Warburg effect. In contrast, CerS4 or CerS5 depletion in Caco-2 cells reduced tumor growth in vivo. Lipidomic and proteomic analysis of membrane fractions revealed significant changes in tumor-promoting cellular pathways and cellular transporters. This study identifies CerS4 and CerS5 as prognostic markers for advanced colon cancer patients and provides a comprehensive overview about the associated cellular metabolic changes. We propose that the expression level of CerS4 and CerS5 in colon tumors could serve as a basis for decision-making for personalized treatment of advanced colon cancer patients. Trial registration: The study was accredited by the study board of the Deutsche Krebsgesellschaft (Registration No: St-D203, 2017/06/30, retrospectively registered).

Long noncoding RNA LINC00649 functions as a microRNA‑432‑5p sponge to facilitate tumourigenesis in colorectal cancer by upregulating HDGF

Long intergenic nonprotein coding RNA 649 (LINC00649) is a functional regulator in acute myeloid leukaemia. However, the contribution of LINC00649 in colorectal cancer (CRC) has yet to be confirmed. Accordingly, the present investigation was devoted to exploring the detailed functions of LINC00649 and reveal the mechanisms underlying the LINC00649-induced promotion of CRC progression. LINC00649 expression in CRC was investigated by reverse transcription-quantitative PCR. Knockdown of LINC00649 was achieved using small interfering RNAs or short hairpin RNA, followed by functional experiments. The binding between LINC00649 and microRNA (miR)-432-5p was predicted by a bioinformatics tool, and corroborated by luciferase reporter assay and RNA immunoprecipitation. In the present study, LINC00649 was expressed at a high level in CRC. The aberrant expression of LINC00649 exhibited an inverse association with CRC patient prognosis. Functionally, the downregulation of LINC00649 exerted anticarcinogenic activities in CRC by decreasing cell proliferation, migration, and invasion and inducing cell apoptosis. Furthermore, the growth of CRC cells in vivo was attenuated after LINC00649 deficiency. Mechanistically, LINC00649 functioned as a competitive endogenous RNA by competitively binding to miR-432-5p in CRC cells, inducing an increase in hepatoma-derived growth factor (HDGF). Ultimately, functional rescue experiments highlighted that the exogenous introduction of miR-432-5p inhibitor or HDGF overexpression plasmid partially abated the inhibitory effects of LINC00649 silencing. In conclusion, LINC00649 promoted the aggressiveness of CRC cells by adjusting the miR-432-5p/HDGF axis. Thus, the LINC00649/miR-432-5p/HDGF pathway may be a promising target for CRC therapy.

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.

Use Chou's 5-steps rule to study how Baicalin suppresses the malignant phenotypes and induces the apoptosis of colorectal cancer cells

Baicalin is a traditional Chinese herb purified from the root of Scutellaria baicalensis Georgi. In this study, we further analyzed the molecular mechanism behind the anti-tumor activity of Baicalin in colorectal cancer (CRC). The establishment of circular RNA (circRNA)/microRNA (miRNA)/messenger RNA (mRNA) axis was predicted by bioinformatic databases and verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Baicalin dose-dependently reduced the expression of circRNA myosin heavy chain 9 (circMYH9) in CRC cells. Baicalin exposure suppressed the malignant phenotypes of CRC cells, which were largely reversed by the overexpression of circMYH9. CircMYH9 functioned as a molecular sponge for miR-761. CircMYH9 overexpression protected CRC cells from Baicalin-induced injury partly through down-regulating miR-761. MiR-761 interacted with the 3' untranslated region (3' UTR) of hepatoma-derived growth factor (HDGF) mRNA. CircMYH9 up-regulated HDGF expression partly through sponging miR-761 in CRC cells. MiR-761 silencing counteracted the anti-tumor activity of Baicalin partly through up-regulating HDGF in CRC cells. Baicalin suppresses xenograft tumor growth in vivo, and this suppressive effect was partly reversed by the overexpression of circMYH9. In conclusion, Baicalin exhibited an anti-tumor activity in CRC cells partly through down-regulating circMYH9 and HDGF and up-regulating miR-761.

miR-4323 targets hepatoma-derived growth factor (HDGF) to suppress colorectal cancer cell proliferation

MicroRNAs (miRNAs) are regulators of cancer progression via directly binding to the 3' untranslated region (3'UTR) of target genes to control the activity of signaling network. Recent studies have revealed the function of several miRNAs in colorectal cancer, however, there are still numerous miRNAs which have not been studied yet. Herein, we showed that miR-4323 was a downregulated miRNA according to previous microarray data. The downregulation of miR-4323 was further confirmed in colorectal tumors via RT-qPCR. miR-4323 overexpression decreased cell proliferation rate via induction of cell apoptosis in colorectal cancer cells. Mechanistically, miR-4323 decreased β-catenin and its downstream genes including c-Myc and MMP9 in colorectal cancer cells, indicating the inactivation of Wnt signaling. HDGF, an anti-apoptotic protein, was predicted by several software as a potential target of miR-4323. HDGF was experimentally verified as a target gene of miR-4323 using dual luciferase reporter assay. Ectopic expression of HDGF attenuated the effect of miR-4323 on cell proliferation and apoptosis in cells. Altogether, the data demonstrate a critical role of miR-4323 in the regulation of colorectal cancer.

Solute carrier family 12 member 2 as a proteomic and histological biomarker of dysplasia and neoplasia in ulcerative colitis

BACKGROUND AND AIMS

Ulcerative colitis (UC) patients have a greater risk of developing colorectal cancer through inflammation-dysplasia-carcinoma sequence of transformation. The histopathological diagnosis of dysplasia is therefore of critical clinical relevance, but dysplasia may be difficult to distinguish from inflammatory changes.

METHODS

A proteomic pilot study on 5 UC colorectal dysplastic patients highlighted proteins differentially distributed between paired dysplastic, inflammatory and normal tissues. The best candidate marker was selected and immunohistochemistry confirmation was performed on AOM/DSS mouse model lesions, 37 UC dysplasia, 14 UC cancers, 23 longstanding UC, 35 sporadic conventional adenomas, 57 sporadic serrated lesions and 82 sporadic colorectal cancers.

RESULTS

Differential proteomics found 11 proteins significantly more abundant in dysplasia compared to inflammation, including Solute carrier family 12 member 2 (SLC12A2) which was confidently identified with 8 specific peptides and was below the limit of quantitation in both inflammatory and normal colon. SLC12A2 immunohistochemical analysis confirmed the discrimination of preneoplastic and neoplastic lesions from inflammatory lesions in mice, UC and in sporadic contexts. A specific SLC12A2 staining pattern termed "loss of gradient" reached 89% sensitivity, 95% specificity and 92% accuracy for UC-dysplasia diagnosis together with an inter-observer agreement of 95.24% (multirater κfree of 0.90; IC95%: 0.78 - 1.00). Such discrimination could not be obtained by Ki67 staining. This specific pattern was also associated with sporadic colorectal adenomas and cancers.

CONCLUSIONS

We found a specific SLC12A2 immunohistochemical staining pattern in precancerous and cancerous colonic UC-lesions which could be helpful for diagnosing dysplasia and cancer in UC and non-UC patients.

Hepatoma-Derived Growth Factor: An Overview and Its Role as a Potential Therapeutic Target Molecule for Digestive Malignancies

Hepatoma-derived growth factor (HDGF) was identified in research seeking to find a novel growth factor for hepatoma cells. Subsequently, four HDGF-related proteins were identified, and these proteins are considered to be members of a new gene family. HDGF has a growth-stimulating role, an angiogenesis-inducing role, and a probable anti-apoptotic role. HDGF is ubiquitously expressed in non-cancerous tissues, and participates in organ development and in the healing of damaged tissues. In addition, the high expression of HDGF was reported to be closely associated with unfavorable clinical outcomes in several malignant diseases. Thus, HDGF is considered to contribute to the development and progression of malignant disease. We herein provide a brief overview of the factor and its functions in relation to benign and malignant cells. We also describe its possible role as a target molecule for digestive malignancies.

Proteomics analysis of colon cancer progression

BACKGROUND

The aim of this pilot study was to identify proteins associated with advancement of colon cancer (CC).

METHODS

A quantitative proteomics approach was used to determine the global changes in the proteome of primary colon cancer from patients with non-cancer normal colon (NC), non-adenomatous colon polyp (NAP), non-metastatic tumor (CC NM) and metastatic tumor (CC M) tissues, to identify up- and down-regulated proteins. Total protein was extracted from each biopsy, trypsin-digested, iTRAQ-labeled and the resulting peptides separated using strong cation exchange (SCX) and reverse-phase (RP) chromatography on-line to electrospray ionization mass spectrometry (ESI-MS).

RESULTS

Database searching of the MS/MS data resulted in the identification of 2777 proteins which were clustered into groups associated with disease progression. Proteins which were changed in all disease stages including benign, and hence indicative of the earliest molecular perturbations, were strongly associated with spliceosomal activity, cell cycle division, and stromal and cytoskeleton disruption reflecting increased proliferation and expansion into the surrounding healthy tissue. Those proteins changed in cancer stages but not in benign, were linked to inflammation/immune response, loss of cell adhesion, mitochondrial function and autophagy, demonstrating early evidence of cells within the nutrient-poor solid mass either undergoing cell death or adjusting for survival. Caveolin-1, which decreased and Matrix metalloproteinase-9, which increased through the three disease stages compared to normal tissue, was selected to validate the proteomics results, but significant patient-to-patient variation obfuscated interpretation so corroborated the contradictory observations made by others.

CONCLUSION

Nevertheless, the study has provided significant insights into CC stage progression for further investigation.

Proteomics analysis of colon cancer progression

BACKGROUND

The aim of this pilot study was to identify proteins associated with advancement of colon cancer (CC).

METHODS

A quantitative proteomics approach was used to determine the global changes in the proteome of primary colon cancer from patients with non-cancer normal colon (NC), non-adenomatous colon polyp (NAP), non-metastatic tumor (CC NM) and metastatic tumor (CC M) tissues, to identify up- and down-regulated proteins. Total protein was extracted from each biopsy, trypsin-digested, iTRAQ-labeled and the resulting peptides separated using strong cation exchange (SCX) and reverse-phase (RP) chromatography on-line to electrospray ionization mass spectrometry (ESI-MS).

RESULTS

Database searching of the MS/MS data resulted in the identification of 2777 proteins which were clustered into groups associated with disease progression. Proteins which were changed in all disease stages including benign, and hence indicative of the earliest molecular perturbations, were strongly associated with spliceosomal activity, cell cycle division, and stromal and cytoskeleton disruption reflecting increased proliferation and expansion into the surrounding healthy tissue. Those proteins changed in cancer stages but not in benign, were linked to inflammation/immune response, loss of cell adhesion, mitochondrial function and autophagy, demonstrating early evidence of cells within the nutrient-poor solid mass either undergoing cell death or adjusting for survival. Caveolin-1, which decreased and Matrix metalloproteinase-9, which increased through the three disease stages compared to normal tissue, was selected to validate the proteomics results, but significant patient-to-patient variation obfuscated interpretation so corroborated the contradictory observations made by others.

CONCLUSION

Nevertheless, the study has provided significant insights into CC stage progression for further investigation.

A novel SNP in the 5' regulatory region of organic anion transporter 1 is associated with chronic kidney disease

We aimed to analyze the associations of single nucleotide polymorphisms (SNP) in the 5′ regulatory region of the human organic anion transporter 1 (OAT1) gene with chronic kidney disease (CKD). A case-control study including age- and sex-matched groups of normal subjects and patients with CKD (n = 162 each) was designed. Direct sequencing of the 5′ regulatory region (+88 to −1196 region) showed that patients with CKD had a higher frequency of the −475 SNP (T > T/G) than normal subjects (14/162 vs. 2/162). The luciferase activity assay results indicated that the −475G SNP had a higher promoter efficiency than the −475T SNP. Chromatin immunoprecipitation (ChIP) and LC/MS/MS analyses showed that the −475G SNP up-regulated 26 proteins and down-regulated 74 proteins. The Southwestern blot assay results revealed that the −475G SNP decreased the binding of Hepatoma-derived growth factor (HDGF), a transcription repressor, compared to the −475T SNP. Overexpression of HDGF significantly down-regulated OAT1 in renal tubular cells. Moreover, a zebrafish animal model showed that HDGF-knockdown zebrafish embryos had higher rates of kidney malformation than wild-type controls [18/78 (23.1%) vs. 1/30 (3.3%)]. In conclusion, our results suggest that an OAT1 SNP might be clinically associated with CKD. Renal tubular cells with the −475 SNP had increased OAT1 expression, which resulted in increased transportation of organic anion toxins into cells. Cellular accumulation of organic anion toxins caused cytotoxicity and resulted in CKD.

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.

MicroRNA-511 Inhibits Cellular Proliferation and Invasion in Colorectal Cancer by Directly Targeting Hepatoma-Derived Growth Factor

Dysregulated microRNA (miRNA) expression is involved in the occurrence and development of colorectal cancer (CRC) through the regulation of various important physiological events. Hence, miRNAs may be used as effective targets for CRC treatment; however, this hypothesis warrants further investigation. miRNA-511 (miR-511) plays vital roles in the progression of different tumor types. However, the expression, exact role, and the mechanisms underlying the regulation of colorectal carcinogenesis and progression by miR-511 remain poorly understood. This study presents that miR-511 expression was decreased in CRC tissues and cell lines compared with that in adjacent nonneoplastic tissues and normal human colon epithelium cell lines, respectively. The enforced expression of miR-511 in CRC cells significantly reduced cell proliferation and invasion. Hepatoma-derived growth factor (HDGF) was mechanically validated as a direct target of miR-511 in CRC. Furthermore, miR-511 was negatively associated with HDGF in CRC tissues. The restored HDGF expression can abrogate the tumor-suppressive roles of miR-511 in CRC cells. More importantly, miR-511 overexpression suppressed the PI3K/AKT signaling pathway in CRC. These results suggest that miR-511 can potentially serve as a therapeutic target for the therapy of patients with CRC.

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.

Hepatoma-derived growth factor promotes growth and metastasis of hepatocellular carcinoma cells

We aimed to elucidate the effects of hepatoma-derived growth factor (HDGF) on growth and metastasis of hepatocellular carcinoma (HCC) cells. Tissue microarrays with 236 HCC specimens and 18 extrahepatic metastases were utilized to detect the HDGF expression by immunohistochemistry. Meanwhile, HDGF expressions in HCC cell lines with different metastatic potentials were examined using immunofluorescence staining, real-time PCR and western blotting. After HDGF silencing, the growth and metastatic potentials of HCC cells were evaluated by soft agar assay, invasion assay, together with tumorigenicity assay in nude mice. The gelatin zymography was performed by detecting MMP-2 and MMP-9 levels. Additionally, western blotting was conducted to determine the levels of total and phosphorylated ERK1/2, JNK, p38 and Akt. The results showed that HDGF was overexpressed in HCC metastasis tumour, and the expression increased with the differentiation degree of tumours (Grade I 44.0%, Grade II 48.4% and Grade III 65.6%). Consistently, HDGF levels were positively associated with the metastatic capability of HCC cells (MHCC97L < MHCC97H < HCCLM3). The growth and metastasis were suppressed by HDGF-siRNA. Gelatinolytic activities were enhanced in the three metastatic HCC cell lines, but had no significant difference among them. The tumourigenicity and metastatic capability of HCCLM3 cells in nude mice were inhibited after silencing HDGF. Meanwhile, HDGF-siRNA specifically suppressed the total and phosphorylated protein levels of ERK1/2, while not JNK, p38 and Akt. In conclusion, HDGF was overexpressed in HCC patients and cells, and HDGF might be closely correlated with HCC metastasis via regulating ERK signalling pathway. Copyright © 2016 John Wiley & Sons, Ltd.

A proteomics approach to identifying novel protein targets involved in erinacine A-mediated inhibition of colorectal cancer cells' aggressiveness

Erinacine A, a major active component of a diterpenoid derivative isolated from Hericium erinaceus mycelium, has been demonstrated to exert anticancer effects. Herein, we present an investigation of the molecular mechanism of erinacine A induction associated with cancer cells’ aggressive status and death. A proteomic approach was used to purify and identify the differentially expressed proteins following erinacine A treatment and the mechanism of its action in apoptotic and the targets of erinacine A. Our results demonstrate that erinacine A treatment of HCT‐116 and DLD‐1 cells increased cell cytotoxicity and reactive oxygen species (ROS) production as well as decreased cell proliferation and invasiveness. Ten differentially displayed proteins were determined and validated in vitro and in vivo between the erinacine A‐treated and untreated groups. In addition, erinacine A time‐dependent induction of cell death and inhibitory invasiveness was associated with sustained phosphorylation of the PI3K/mTOR/p70S6K and ROCK1/LIMK2/Cofilin pathways. Furthermore, we demonstrated that erinacine A–induced HCT‐116 and DLD‐1 cells viability and anti‐invasion properties by up‐regulating the activation of PI3K/mTOR/p70S6K and production of ROS. Experiments involving specific inhibitors demonstrated that the differential expression of cofilin‐1 (COFL1) and profilin‐1 (PROF1) during erinacine A treatment could be involved in the mechanisms of HCT‐116 and DLD‐1 cells death and decreased aggressiveness, which occurred via ROCK1/LIMK2/Cofilin expression, with activation of the PI3K/mTOR/p70S6K signalling pathway. These findings elucidate the mechanism of erinacine A inhibiting the aggressive status of cells by activating PI3K/mTOR/p70S6K downstream signalling and the novel protein targets COF1 and PROF1; this could be a good molecular strategy to limit the aggressiveness of CRC cells.

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.

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.

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.

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.

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.

Proteomic Changes Induced by Podophyllotoxin in Human Cervical Carcinoma HeLa Cells

Podophyllotoxin, a kind of lignan extracted from the Podophyllum plant, has been shown to inhibit the growth of various carcinoma cells. However, the molecular mechanism remains unclear. In this study, the inhibition of cell growth and changes in protein expression induced by podophyllotoxin were investigated in human cervical carcinoma HeLa cells. Our results demonstrate that Podophyllotoxin inhibits HeLa cell growth and induces apoptosis. By using proteomic techniques, seven proteins were found to be significantly regulated by podophyllotoxin compared to the untreated control; among them, four were down-regulated and three were up-regulated. All of the seven proteins were identified with peptide mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) after in-gel trypsin digestion. Five of these proteins are involved in protein metabolism, and the other two play roles in cell communication and signaling transduction pathways. It is suggested that the effect of podophyllotoxin on the growth of tumor cells is significantly related to the metabolism-associated proteins.

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.

Curcumin inhibits proliferation and induces apoptosis of human colorectal cancer cells by activating the mitochondria apoptotic pathway

Curcumin, a natural plant extract from Curcuma longa, is known for its anti-carcinogenic and chemopreventive effects on a variety of experimental cancer models. In this study, we evaluated the effects of curcumin and elucidated its mechanism in human colorectal carcinoma cells. Cell viability assay showed that curcumin significantly inhibited the growth of LoVo cells. Curcumin treatment induced the apoptosis accompanied by ultra-structural changes and release of lactate dehydrogenase in a dose-dependent manner. Moreover, treatment with 0-30 µg/mL curcumin decreased the mitochondrial membrane potential and activated the caspase-3 and caspase-9 in a dose- and time-dependent manner. Nuclear and annexin V/PI staining showed that curcumin induced the apoptosis of LoVo cells. FACS analysis revealed that curcumin could induce the cell cycle arrest of LoVo cells at the S phase. Furthermore, western blotting analysis indicated that curcumin induced the release of cytochrome c, a significant increase of Bax and p53 and a marked reduction of Bcl-2 and survivin in LoVo cells. Taken together, our results suggested that curcumin inhibited the growth of LoVo cells by inducing apoptosis through a mitochondria-mediated pathway.

S100A6 is transcriptionally regulated by β-catenin and interacts with a novel target, lamin A/C, in colorectal cancer cells

In this paper we document an increased expression of S100A6, a calcium binding protein of the S100 family, and its co-localization with β-catenin in colorectal cancer tissues and in metastatic, SW620, versus non-metastatic, SW480, human colorectal cancer cell lines. Moreover, we show up-regulation of the S100A6 protein level in non-metastatic SW480 cells due to overexpression of β-catenin as well as the activation of the S100A6 gene promoter upon cell transfection with β-catenin and the TCF-Lef1 transcription factor. Since we found a high level of S100A6 in metastatic SW620 cells we searched for its interacting partners in the protein extract prepared from these cells. Using several methods we found that S100A6 interacts with lamin A/C, a protein known to be implicated in colon carcinogenesis. Our results reveal a novel and important network of relations and interactions between proteins potentially involved in colorectal cancer development and progression.

Overexpression of hepatoma-derived growth factor in melanocytes does not lead to oncogenic transformation

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.