Expression of Basic Fibroblast Growth Factor in Rat Liver Fibrosis and Hepatic Stellate Cells

Summary:The expression of basic fibroblast growth factor (bFGF) in rat liver fibrosis and hepatic stellate cells (HSCs) and the relationship between the expression of bFGF and rat liver fibrogenesis were studied. Sixty male SD rats (230-260 g) were divided into 4 groups randomly (the 0 week group, 1 week group, 4 week group and 8 week group). Liver fibrosis was induced by subcutaneous injection of carbon tetrachloride. The sections of rats' liver in each group were tested by Van-Gieson (V-G) staining and immunohistochemistry. The expression of bFGF mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). HSCs were isolated by the combined methods of collagenase IV perfusion and density gradient centrifugation. The expression of bFGF protein in cultured HSCs was detected by Western blot. Images of immunohistochemistry detection, agarose gel electrophoresis of RT-PCR and SDS-polyacrylamide gel electrophoresis of Western blot were analyzed semiquantitatively by image-analyzing system. The results were analyzed by statistics. The results showed that the fibers were gradually increased in the sections of rat liver with the prolongation of the model induction. At the end of the 8th weeks, liver fibrosis was formed. The expression of bFGF detected by immunohistochemistry showed a similar tendency of gradual increase. At the end of the 8th weeks, the bFGF expression could be observed in many regions in sections and the strongest expression was in interstitial cells including HSCs and some hepatocytes in regions around the portal area and central veins. Also there was moderate expression widely in extracellular matrix (ECM). In RT-PCR detection and Western blot detection of HSCs cultured in vitro, the similar tendency of gradual increase was evident either. It is suggested that bFGF is related with liver fibrosis of rats closely and may be a fibrogenesis factor of liver. bFGF possibly regulates liver fibrogenesis through regulating metabolism of extracellular matrix (ECM) by autocrine and paracrine stimulation.

Changes in growth factor and cytokine expression in biliary obstructed rat liver and their relationship with delayed liver regeneration after partial hepatectomy

AIM： To study the effects of obstructive jaundice on liver regeneration after partial hepatectomy. METHODS： Hepatocyte growth factor （HGF）, its receptor, c-Met, vascular endothelial growth factor （VEGF） and transforming growth factor-β1 （TGF-β1） mRNA expression in both liver tissue and isolated liver cells were investigated after biliary obstruction （BO） by quantitative reverse-transcription polymerase chain reaction （RT-PCR） using a LightCycler. Immunohistochemical staining for desmin and e-smooth muscle actin （α-SNA） was also studied. Regenerating liver weight and proliferating cell nuclear antigen （PCNA） labeling index, and growth factor expression were then evaluated after 70% hepatectomy with concomitant internal bUiary drainage in BO rats or sham-operated rats. RESULTS： Hepatic TGF-β1 mRNA levels increased significantly 14 days after BO, and further increased with duration of cholestasis. Meanwhile, HGF and VEGF tended to increase, but was not significant. In cell isolates, TGF-β1 mRNA was found mainly in the hepatic stellate cell （HSC） fraction. Immunohistochemical studies revealed an increased number of HSCs （desmin-positive cells） and activated HSCs （α-SMA-positive cells） in portal areas after BO. In a hepatectomy model, liver regeneration was delayed in BO rats, as compared to sham-operated rats. TGF-β1 mRNA was significantly up-regulated up to 48 h after hepatectomy, and the earlier HGF mRNA peak was lost in BO rats. CONCLUSION： BO induces HSCs proliferation and activation, leading to up-regulation of TGF-β1 mRNA and suppression of HGF mRNA in livers. These altered expression patterns may be strongly involved in delayed liver regeneration after hepatectomy with obstructive jaundice.

Growth factor-and cytokine-driven pathways governing liver stemness and differentiation

Liver is unique in its capacity to regenerate in response to injury or tissue loss. Hepatocytes and other liver cells are able to proliferate and repopulate the liver. However, when this response is impaired, the contribution of hepatic progenitors becomes very relevant. Here, we present an update of recent studies on growth factors and cytokine-driven intracellular pathways that govern liver stem/pro-genitor cell expansion and differentiation, and the rel-evance of these signals in liver development, regeneration and carcinogenesis. Tyrosine kinase receptor signaling, in particular, c-Met, epidermal growth factor receptors or fibroblast growth factor receptors, contribute to prolifera-tion, survival and differentiation of liver stem/progenitor cells. Different evidence suggests a dual role for the trans-forming growth factor (TGF)-β signaling pathway in liver stemness and differentiation. On the one hand, TGF-βmediates progression of differentiation from a progenitor stage, but on the other hand, it contributes to the expan-sion of liver stem cells. Hedgehog family ligands are nec-essary to promote hepatoblast proliferation but need to be shut off to permit subsequent hepatoblast differentiation. In the same line, the Wnt family and β-catenin/T-cell fac-tor pathway is clearly involved in the maintenance of liver stemness phenotype, and its repression is necessary for liver differentiation during development. Collectively, data indicate that liver stem/progenitor cells follow their own rules and regulations. The same signals that are essential for their activation, expansion and differentiation are good candidates to contribute, under adequate conditions, to the paradigm of transformation from a pro-regenerative to a pro-tumorigenic role. From a clinical perspective, this is a fundamental issue for liver stem/progenitor cell-based therapies.

Reduction of tumorigenicity of SMMC-7721 hepatoma cells by vascular endothelial growth factor antisense gene therapy

AIM: To test the hypothesis to block VEGF expression of SMMC-7721 hepatoma cells may inhibit tumor growth using the rat hepatoma model. METHODS: Amplify the 200 VEGF cDNA fragment and insert it into human U6 gene cassette in the reverse orientation transcribing small antisense RNA which could specifically interact with VEGF165, and VEGF121 mRNA. Construct the retroviral vector containing this antisense VEGF U6 cassette and package the replication-deficient recombinant retrovirus. SMMC-7721 cells were transduced with these virus and positive clones were selected with G418. PCR and Southern blot analysis were performed to determine if U6 cassette integrated into the genomic DNA of positive clone. Transfected tumor cells were evaluated for RNA expression by ribonuclease protection assays. The VEGF protein in the supernatant of parental tumor cells and genetically modified tumor cells was determined with ELISA. In vitro and in vivo growth properties of antisense VEGF cell clone in nude mice were analyzed. RESULTS: Restriction enzyme digestion and PCR sequencing verified that the antisense VEGF RNA retroviral vector was successfully constructed.After G418 selection, resistant SMMC-7721 cell clone was picked up. PCR and Southern blot analysis suggested that U6 cassette was integrated into the cell genomic DNA. Stable SMMC-7721 cell clone transduced with U6 antisense RNA cassette could express 200 bp small antisense VEGF RNA and secrete reduced levels of VEGF in culture condition. Production of VEGF by antisense transgene-expressing cells was 65+/-10 ng/L per 10(6) cells, 42045 ng/L per 10(6) cells in sense group and 485+/-30 ng/L per 10(6) cells in the negative control group, (P【 0.05). The antisense-VEGF cell clone appeared phenotypically indistinguishable from SMMC-7721 cells and SMMC-7721 cells transfected sense VEGF. The growth rate of the antisense-VEGF cell clone was the same as the control cells. When S.C. was implanted into nude mice, growth of antisense-VEGF cell lines was greatly inhibited compared with control cells. CONCLUSION: Expression of antisense VEGF RNA in SMMC-7721 cells could decrease the tumorigenicity, and antisense-VEGF gene therapy may be an adjuvant treatment for hepatoma.

Effect of transforming growth factor beta and bone morphogenetic proteins on rat hepatic stellate cell proliferation and transdifferentiation

AIM: To explore different roles of TGF-β (transforming growth factor beta) and bone morphogenetic proteins (BMPs)in hepatic stellate cell proliferation and trans-differentiation.METHODS: Hepatic stellate cells were isolated from male Sprague-Dawley rats. Sub-cultured hepatic stellate cells were employed for cell proliferation assay with WST-1 reagent and Western blot analysis with antibody against smooth muscle alpha actin (SMA).RESULTS: The results indicated that TGF-β1 significantly inhibited cell proliferation at concentration as low as 0.1 ng/ml, but both BMP-2 and BMP-4 did not affect cell proliferation at concentration as high as 10 ng/ml. The effect on hepatic stellate cell trans-differentiation was similar between TGFβ1 and BMPs. However, BMPs was more potent at transdifferentiation of hepatic stellate cells than TGF-β1. In addition, we observed that TGF-β1 transient reduced the abundance of SMA in hepatic stellate cells.CONCLUSION: TGF-β may be more important in regulation of hepatic stellate cell proliferation while BMPs may be the major cytokines regulating hepatic stellate cell transdifferentiation.

Hepatocyte growth factor gene therapy prevents radiation-induced liver damage

AIM: To transfer human HGF gene into the liver of rats by direct electroporation as a means to prevent radiationinduced liver damage.METHODS: Rat whole liver irradiation model was accomplished by intra-operative approach. HGF plasmid was injected into liver and transferred by electroporation using a pulse generator. Control rats (n = 8) received electrogene therapy (EGT) vehicle plasmid and another 8rats received HGF-EGT 100 μg 48 h before WLIR.Expression of HGF in liver was examined by RT-PCR and ELISA methods. Apoptosis was determined by TUNEL assay. Histopathology was evaluated 10 wk after whole liver irradiation.RESULTS: Marked decrease of apoptotic cells and downregulation of transforming growth factor-beta 1 (TGF-β1)mRNA were observed in the HGF-EGT group 2 d after liver irradiation compared to control animals. Less evidence of radiation-induced liver damage was observed morphologically in liver specimen 10 wk after liver irradiation and longer median survival time was observed from HGF-EGT group (14 wk) compared to control rats (5 wk). (P = 0.031).CONCLUSION: For the first time it has been demonstrated that HGF-EGT would prevent liver from radiation-induced liver damage by preventing apoptosis and down-regulation of TGF-β1.

Transcription factor EGR-1 inhibits growth of hepatocellular carcinoma and esophageal carcinoma cell lines

AIM: The transcription factor EGR-1 (early growth response gene-1) plays an important role in cell growth, differentiation and development. It has identified that EGR-1 has significant transformation suppression activity in some neoplasms, such as fibrosarcoma, breast carcinoma. This experiment was designed to investigate the role of egr-1 in the cancerous process of hepatocellular carcinoma (HCC) and esophageal carcinoma (EC), and then to appraise the effects of EGR-1 on the growth of these tumor cells. METHODS: Firstly, the transcription and expression of egr-1 in HCC and EC, paracancerous tissues and their normal counterpart parts were detected by in situ hybridization and immunohistochemistry, with normal human breast and mouse brain tissues as positive controls. Egr-1 gene was then transfected into HCC (HHCC, SMMC7721) and EC (ECa109) cell lines in which no egr-1 transcription and expression were present. The cell growth speed, FCM cell cycle, plate clone formation and tumorigenicity in nude mice were observed and the controls were the cell lines transfected with vector only. RESULTS: Little or no egr-1 transcription and expression were detected in HCC, EC and normal liver tissues. The expression of egr-1 were found higher in hepatocellular paracancerous tissue (transcription level P=0.000; expression level P=0.143, probably because fewer in number of cases) and dysplastic tissue of esophageal cancer (transcription level P=0.000; expression level P=0.001). The growth rate of egr-1-transfected HHCC (HCC cell line) cells and ECa109 (EC cell line) cells was much slower than that of the controls. The proportion of S phase cell, clone formation and tumorigenicity were significantly lower than these of the controls' (decreased 45.5% in HHCC cells and 34.1% in ECa109 cells; 46.6% and 41.8%; 80.4% and 72.6% respectively). There were no obvious differences between SMMC7721 (HCC) egr-1-transfected cells and the controls with regard to the above items. CONCLUSION: The decreased expression of egr-1 might play a role in the dysregulation of normal growth in the cancerous process of HCC and EC. Egr-1 gene of transfected HHCC and ECa109 cells showed obvious suppression of the cell growth and malignant phenotypes, but no suppression in SMMC7721 (HCC cell line) cells.

Construction of hepatocyte growth factor gene recombinant adenovirus vector and its expression in rat bone marrow mesenchymal stem cells

Objective：To construct the adenoviral expression vector system containing human hepatocyte growth factor （hHGF） cDNA, and to further study the transduction efficiency and the expression of HGF in mesenchymal stem cells （MSCs）. Methods：The HGF cDNA was amplificated from the expression plasmid pCMV-HGF, and was subcloned into the adenovirus shuttle plasmid pDC316-IRESEGFP vector containing a green fluorescence protein （GFP） reporter gene. Virus Ad-HGF was produced by homologous recombination in HEK293 package cells. Bone marrow derived MSCs were harvested and cultured, and then were transduced with Ad-HGF. The efficiency of Ad-HGF transduction was assessed by FACS analysis using GFP gene expression. And HGF/MSCs were generated. The HGF concentrations in supernatants of HGF/MSCs were determined by ELISA using anti-human HGF monoclonal antibody. Results： The recombinant, named pDC316-HGF-IRES-eGFP, was digested with restriction enzyme, and the DNA sequencing of HGF was identical to the report in Genebank and did not reveal any mutation. GFP expression could be observed on the second day after packing of the linearized pAd-HGF in HEK293 cells and 7.15 × 10^10pfu/ml titer of Ad-HGF was obtained. Forty-eight hours after transduction, 96.89% of HGF/MSCs were GFP positive. Peak concentration levels of hHGF（103ng/mL） in the cultured supernatants were detected on day 2 post-transduction, and the adenovirus-mediated expression of HGF by MSCs was maintained for at least 2 weeks in vivo. Conclusion：Our data demonstrated that the adenovirus expression＇vector system pDC316-HGF-IRES-EGFP has been constructed successfully, and their effective expressions also have been obtained in MSCs. This will provide material basis for the next study on liver regeneration after small-for-size liver transplantation.

Hematotesticular barrier is altered from early stages of liver cirrhosis:Effect of insulin-like growth factor 1

AIM:The pathogenesis of hypogonadism in liver cirrhosis is not well understood.Previous results from our laboratory showed that IGF-1 deficiency might play a pathogenetic role in hypogonadism of cirrhosis.The administration of IGF-1 for a short period of time reverted the testicular atrophy associated with advanced experimental cirrhosis. The aim of this study was to establish the historical progression of the described alterations in the testes, explore testicular morphology,histopathology,cellular proliferation,integrity of testicular barrier and hypophyso- gonadal axis in rats with no ascitic cirrhosis. METHODS:Male Wistar rats with histologically-proven cirrhosis induced with carbon tetrachloride(CCI_4)for 11 wk, were allocated into two groups(n=12,each)to receive recombinant IGF-1(2 μg/100 gd,sc)for two weeks or vehicle.Healthy rats receiving vehicle were used as control group(n=12). RESULTS:Compared to controls,rats with compensated cirrhosis showed a normal testicular size and weight and very few histopathological testicular abnormalities. However,these animals showed a significant diminution of cellular proliferation and a reduction of testicular transferrin expression.In addition,pituitary-gonadal axis was altered,with significant higher levels of FSH(P<0.001 vscontrols)and increased levels of LH in untreated cirrhotic animals.Interestingly,IGF-1 treatment normalized testicular transferrin expression and cellular proliferation and reduced serum levels of LH(P=ns vs controls,and P<0.01 vs untreated cirrhotic group). CONCLUSION:The testicular barrier is altered from an early stage of cirrhosis,shown by a reduction of transferrin expression in Sertoli cells,a diminished cellular proliferation and an altered gonadal axis.The treatment with IGF-1 could be also useful in this initial stage of testicular disorder associated with compensated cirrhosis.

Bone morphogenetic protein-7 represses hepatic stellate cell activation and liver fibrosis via regulation of TGF-β/Smad signaling pathway

BACKGROUND Liver fibrosis is a refractory disease whose persistence can eventually induce cirrhosis or even liver cancer.Early liver fibrosis is reversible by intervention.As a member of the transforming growth factor-beta(TGF-β)superfamily,bone morphogenetic protein 7(BMP7)has anti-liver fibrosis functions.However,little is known about BMP7 expression changes and its potential regulatory mechanism as well as the relationship between BMP7 and TGF-βduring liver fibrosis.In addition,the mechanism underlying the anti-liver fibrosis function of BMP7 needs to be further explored.AIM To investigate changes in the dynamic expression of BMP7 during liver fibrosis,interactions between BMP7 and TGF-β1,and possible mechanisms underlying the anti-liver fibrosis function of BMP7.METHODS Changes in BMP7 expression during liver fibrosis and the interaction between BMP7 and TGF-β1 in mice were observed.Exogenous BMP7 was used to treat mouse primary hepatic stellate cells(HSCs)to observe its effect on activation,migration,and proliferation of HSCs and explore the possible mechanism underlying the anti-liver fibrosis function of BMP7.Mice with liver fibrosis received exogenous BMP7 intervention to observe improvement of liver fibrosis by using Masson’s trichrome staining and detecting the expression of the HSC activation indicator alpha-smooth muscle actin(α-SMA)and the collagen formation associated protein type I collagen(Col I).Changes in the dynamic expression of BMP7 during liver fibrosis in the human body were further observed.RESULTS In the process of liver fibrosis induced by carbon tetrachloride(CCl4)in mice,BMP7 protein expression first increased,followed by a decrease;there was a similar trend in the human body.This process was accompanied by a sustained increase in TGF-β1 protein expression.In vitro experiment results showed that TGF-β1 inhibited BMP7 expression in a time-and dose-dependent manner.In contrast,high doses of exogenous BMP7 inhibited TGF-β1-induced activation,migration,and proliferation of HSCs;this inhibitory effect was associated with upregulation of pSmad1/5/8 and downregulation of phosphorylation of Smad3 and p38 by BMP7.In vivo experiment results showed that exogenous BMP7 improved liver fibrosis in mice.CONCLUSION During liver fibrosis,BMP7 protein expression first increases and then decreases.This changing trend is associated with inhibition of BMP7 expression by sustained upregulation of TGF-β1 in a time-and dose-dependent manner.Exogenous BMP7 could selectively regulate TGF-β/Smad pathway-associated factors to inhibit activation,migration,and proliferation of HSCs and exert antiliver fibrosis functions.Exogenous BMP7 has the potential to be used as an antiliver fibrosis drug.

Vascular endothelial growth factor and angiopoietins regulate sinusoidal regeneration and remodeling after partial hepatectomy in rats

AIM： To study the regulatory mechanisms of sinusoida regeneration after partial hepatectomy. METHODS： We invesldgated the expression of angiopoietin （Ang）-1, Ang-2, Tie-2, and vascular endothelial growth factor （VEGF） in regenerating liver tissue by quantitative reverse-transcription polymerase chain reaction （RT- PCR） using a LightCycler （Roche Diagnostics） and also immunohistochemical staining after 70% hepatectomy in rats. In the next step, we isolated liver cells （hepatocytes, sinusoidal endothelial cell （SEC）, Kupffer cell, and hepatic stellate cells （HSC）） from regenerating liver tissue by in situ collagenase perfusion and counterflow elutriation, to determine potential cellular sources of these angiogenic factors after hepatectomy. Proliferation and apoptosis of SECs were also evaluated by proliferating cell nuclear antigen （PCNA） staining and the terminal deoxynucleotidyl transferase d-uridine triphosphate nick end labeling （TUNEL） assay, respectively. RESULTS： VEGF mRNA expression increased with a peak at 72 h after hepatectomy, decreasing thereafter. The expression of Ang-1 mRNA was present at detectable levels before hepatectomy and increased slowly with a peak at 96 h. Meanwhile, Ang-2 mRNA was hardly detected before hepatectomy, but was remarkably induced at 120 and 144 h. In isolated cells, VEGF mRNA expression was found mainly in the hepatocyte fraction. Meanwhile, mRNA for Ang-1 and Ang-2 was found in the SEC and HSC fractions, but was more prominent in the latter. The PCNA labeling index of SECs increased slowly, reaching a peak at 72 h, whereas apoptotic SECs were detected between 120 h and 144 h. CONCLUSION： Ang-Tie system, together with VEGF, plays a critical role in regulating balance between SEC proliferation and apoptosis during sinusoidal regeneration after hepatectomy. However, the VEGF system plays a more important role in the early phase of sinusoidal regeneration than angiopoietin/Tie system.

SF/HGF-c-Met autocrine and paracrine promote metastasis of hepatocellular carcinoma

AIM: To explore the role of SF/HGF-Met autocrine and paracrine in metastasis of hepatocellular carcinoma (HCC). METHODS: SF/HGF and c-met transcription and protein expression in HCC were examined by RT-PCR and Western Blot in 4 HCC cell lines, including HepG2, Hep3B, SMMC7721 and MHCC-1, the last cell line had a higher potential of metastasis. sf/hgf cDNA was transfected by the method of Lipofectin into SMMC7721. SF/HGF and c-met antibody were used to stimulate and block SF/HGF-c-met signal transduction. Cell morphology, mobility, and proliferation were respectively compared by microscopic observation, wound healing assay and cell growth curve. RESULTS: HCC malignancy appeared to be relative to its met-SF/HGF expression. In MHCC-1, c-met expression was much stronger than that in other cell lines with lower potential of metastasis and only SF/HGF autocrine existed in MHCC-1. After sf/hgf cDNA transfection or conditioned medium of MHCC-1 stimulation, SMMC7721 changed into elongated morphology, and the abilities of proliferation (P 【 0.05) and mobility increased. Such bio-activity could be blocked by c-met antibody (P 【 0.05). CONCLUSION: The system of SF/HGF-c-met autocrine and paracrine played an important role in development and metastasis potential of HCC. Inhibition of SF/HGF-c-met signal transduction system may reduce the growth and metastasis of HCC.

Osteopontin is an important mediator of alcoholic liver disease via hepatic stellate cell activation

AIM: To investigate over-expression of Osteopontin (OPN) pathway expression and mechanisms of action in human alcoholic liver disease (ALD), in vivo and in vitro acute alcohol models.

IGFBPrP1 induces liver fibrosis by inducing hepatic stellate cell activation and hepatocyte apoptosis via Smad2/3 signaling

AIM: To investigate the role and mechanism of insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) in the development of liver fibrosis.

Prokineticin 2/Bv8 is expressed in Kupffer cells in liver and is down regulated in human hepatocellular carcinoma

AIM： TO study the implication of prokineticin 1 （PKI/EGVEGF） and prokineticin 2 （PK2/13v8） in hepatocellular carcinoma angiogenesis.METHODS： The gene induction of PK1/EG-VEGF and PK2/Bv8 was investigated in 10 normal, 28 fibrotic and 28 tumoral livers by using real time PCR. Their expression was compared to the expression of VEGF （an angiogenesis marker）, vWF （an endothelial cell marker） and to CD68 （a monocyte/macrophage marker）. Furthermore, the rnRNA levels of PK1/EG-VEGF, PK2/Bv8, prokineticin receptor 1 and 2 were evaluated by real time PCR in isolated liver cell populations. Finally, PK2/Bv8 protein was detected in normal liver paraffin sections and in isolated liver cells by immunohistochernistry and immunocytochemistry.RESULTS： PK2/Bv8 mRNA but not PK1/EG-VEGF was expressed in all types of normal liver samples examined. In the context of liver tumor development, we reported that PK2/13v8 correlates only with CD68 and showed a significant decrease in expression as the pathology evolves towards cancer. Whereas, VEGF and vWF mRNA were significantly upregulated in both fibrosis and HCC,as expected. In addition, out of all isolated liver cells examined, only Kupffer cells （liver resident macrophages） express significant levels of PK2/Bv8 and its receptors, prokineticin receptor 1 and 2.CONCLUSION： In normal liver PK2/Bv8 and its receptors were specifically expressed by Kupffer cells. PK2/Bv8 expression decreased as the liver evolves towards cancer and did not correlate with HCC angiogenesis.

HGF/C-Met在舌部鳞状细胞癌的表达及其临床意义

目的:探讨肝细胞生长因子及其受体C-Met蛋白在舌鳞癌中的表达与其临床病理特征之间的关系。方法:通过免疫组化法检测10例正常舌组织、14例舌癌前病变及63例舌鳞癌中肝细胞生长因子、C-Met的表达,数据通过SPSS13.0统计软件非参数秩和检验统计。结果:肝细胞生长因子和C-Met在舌癌、舌癌前病变及正常舌组织的阳性表达率分别为84.1%、57.1%、40.0%和76.2%、35.7%、20.0%,其表达差异均具有统计学意义(P<0.05)。在中、低分化组(90.3%)及有淋巴结转移组(100%)舌鳞癌中肝细胞生长因子的阳性表达率显著高于高分化组(78.1%)及无转移淋巴结组(76.7%);在Ⅲ、Ⅳ期(82.1%)及有淋巴结转移组(85.0%)的舌鳞癌中C-Met阳性表达率显著高于Ⅰ、Ⅱ期(71.4%)及无转移淋巴结组(72.1%),表达差异均具有统计学意义(p<0.05);63例舌癌组织切片中46例HGF及C-Met都有阳性表达,其在舌鳞状细胞癌中的表达显著正相关(P<0.01)。结论:过度表达的HGF/C-Met可作为判断舌鳞状细胞癌生物学行为、恶性潜能和预测淋巴结转移趋势的参考指标。

肝癌间质细胞中HGF/cMET系统的表达对肝癌细胞恶性生物学功能的影响

目的探索肝癌间质细胞与正常肝细胞共培养对肝癌恶性生物学功能的影响,探讨其相互作用所涉及的信号通路,明确肝癌微环境中间质细胞在肿瘤进展中的作用。方法人肝癌间质细胞或人肝细胞生长因子(hepatocyte growth factor,HGF)与肝正常细胞系L-02共培养,检测肝正常细胞中抑癌基因PTEN及癌基因K-RAS的表达及肝正常细胞的增殖变化;Real-time PCR和Western blot检测下游相关信号通路的变化。结果肝癌间质细胞与正常肝细胞L-02共培养使得抑癌基因PTEN的转录水平下调1.15倍,翻译水平下调10倍多(P<0.05),而原癌基因K-RAS的转录水平上调1.4倍,翻译水平上调9倍以上(P<0.05);共培养后的肝细胞增殖能力较对照组增加2倍以上;ELISA实验结果显示,共培养后的培养液中含有较对照组3倍以上的HGF(P<0.05,1 085±108 vs.387±23);同时实验组细胞表达的cMET也较对照组细胞高出4倍以上(P<0.05);外源性HGF一致性促进了肝细胞的增殖能力和活力(P<0.05)。结论肝癌间质细胞可能通过分泌HGF激活HGF/cMET信号通路,促进正常肝细胞的增殖。这为探索肿瘤微环境对肿瘤发生、发展的分子机制及肝癌治疗提供新的途径。

达康灌肠方对溃疡性结肠炎大鼠肠黏膜HGF、c-Met、EGFR及PCNA表达的影响

目的研究中药达康灌肠方(简称达康方)对溃疡性结肠炎大鼠肝细胞生长因子(HGF)、肝细胞生长因子受体(c-Met)、表皮生长因子受体(EGFR)及增殖细胞核抗原(PCNA)表达的影响。方法将SD大鼠分为5组,除空白对照组外,其余大鼠采用TNBS(2,4,6-三硝基苯磺酸)法诱导大鼠溃疡性结肠炎模型。将造模成功的大鼠再分为模型组、达康方高、低剂量组和阳性药(柳氮磺吡啶片,SASP)组,各组进行相应干预。采用免疫组化定量分析(灰度值)的方法检测实验大鼠结肠组织HGF、c-Met、EGFR及PCNA的表达。结果与空白对照组比较,模型组大鼠结肠组织HGF、c-Met、EGFR及PCNA的表达差异均有统计学意义(P<0.05)。与模型组比较,达康方高剂量组及阳性药组HGF、c-Met、EGFR及PCNA的表达增强,达康方低剂量组c-Met、EGFR表达增强,差异均有统计学意义(P<0.05)。达康方高、低剂量组之间比较,HGF及EGFR表达差异有统计学意义(P<0.05)。结论中药达康灌肠方可通过干预HGF、c-Met、EGFR表达而加快结肠黏膜的修复,恢复结肠上皮屏障功能,减少黏膜上皮接触肠腔内造成炎症持续的各种抗原,减轻炎症反应,促进结肠黏膜上皮细胞增殖而修复结肠黏膜损伤。

HGF与CTLA-4Ig双基因修饰增强脐带间充质干细胞的免疫抑制和促增殖作用

【目的】探讨人脐带间充质干细胞(hUCMSC)经肝细胞生长因子(HGF)和细胞毒性T细胞相关抗原4免疫球蛋白(CTLA4-Ig)双基因修饰后免疫调节能力的变化及其促进肝细胞增殖作用的影响。【方法】酶联合消化法提取并鉴定人脐带间充质干细胞;对照组的hUCMSC转染携带绿色荧光蛋白(EGFP)基因的Ad5-EGFP,实验组的hUCMSC转染携带HGF和CTLA-Ig双基因的腺病毒Ad5-HGF/CTLA-4Ig。流式细胞仪检测对照组hUCMSC转染Ad5-EGFP后72 h表达EGFP细胞比率;实验组Ad5-HGF/CTLA-4Ig转染hUCMSC 72 h后,CCK8检测细胞存活率,同时再次检测hUCMSC免疫表型和向成骨细胞分化的能力,ELISA检测细胞上清中HGF含量,Western blot检测细胞中CTLA4-Ig蛋白的表达水平,通过CCK8法检测双基因修饰后hUCMSC对淋巴细胞增殖的影响及其上清对L02细胞增殖的影响。【结果】携带外源基因的腺病毒可有效转染hUCMSC,不影响其干细胞特性和多向分化能力,经HGF/CTLA-4Ig基因修饰hUCMSC可分泌高浓度HGF并高表达CTLA-4Ig,同时能有效地抑制淋巴细胞增殖,其上清能明显促进肝细胞增殖。【结论】hUCMSC经HGF/CTLA-4Ig基因修饰后生物学特性无明显改变,并能高表达HGF和CTLA-4Ig,其免疫调节及促进肝细胞增殖的能力进一步加强,为肝移植术后存在的肝细胞损伤的保护治疗提供了新思路。

抗癌防移片对BALB/c小鼠大肠癌肝转移HGF、VEGF蛋白表达的影响

目的:探究抗癌防移片对于抑制大肠癌肝转移的作用及其机制。方法:采用BALB/c小鼠注入CT26细胞悬液,建立大肠癌小鼠模型,造模成功后的48只小鼠随机分为4组:模型组,西药组,中药组,中西药组,每组12只小鼠,分别予以不同的处理方式干预4周。采用免疫组织化学测定HGF、VEGF蛋白表达光镜下观察,对HGF、VEGF蛋白进行分析比较。结果:模型组与西药组、中西结合组比较,HGF、VEGF蛋白表达明显升高(P<0.01);单纯中药组与西药组、中西结合组相比,HGF、VEGF蛋白表达明显升高(P<0.05);中西结合组与西药组比较,HGF、VEGF蛋白表达下降(P>0.05)。结论:抗癌防移片可能通过抑制HGF、VEGF的表达,抑制血管新生,从而抑制大肠癌肝转移。