通里攻下法对急性肝衰竭大鼠肝细胞凋亡的影响(摘要)

目的:探讨通里攻下法对内毒素脂多糖(LPS)致急性肝衰竭大鼠肝细胞凋亡的影响。方法:以LPS D-GalN联合制备大鼠急性肝衰竭模型,观察大鼠肝组织病理学变化;以免疫组化法(SP法)检测Fas、FasL蛋白在大鼠肝组织中的表达情况,并观察通里攻下中药对肝细胞凋亡的作用。结果:LPS D-GalN可引起严重的急性肝坏死并有广泛的肝细胞凋亡,伴Fas、FasL蛋白在肝细胞中表达增强;肝细胞Fas/FasL阳性     

IL-33及其受体ST2在D-GalN/LPS诱导的急性肝功能衰竭小鼠中的表达及意义

目的研究D-GalN/LPS诱导的急性肝衰竭小鼠中IL-33及其受体ST2的表达及意义。方法腹腔注射DGaIN(900 mg/kg)/LPS(10μg/kg)诱导急性肝衰竭小鼠模型。通过q-PCR、Westcrn印迹、ELISA、免疫组织化学染色等实验技术检测IL-33及其受体ST2在不同时间点的动态变化。结果急性肝衰竭小鼠肝内的IL-33 mRNA水平随着肝损伤加重不断增高,肝衰竭时上升至峰值,D-GalN/LPS诱导后7 h,肝组织表现为明显坏死。而肝内ST2L受体蛋白含量在DGalN/LPS诱导后3 h,未出现明显的肝细胞损伤前已显著升高,之后不断下降,到7 h肝衰竭时其水平降至最低。此外,外周血清中IL-33蛋白水平亦随时间持续升高,在7 h肝衰竭时达高峰,与IL-33 mRNA的动态变化相一致。然而血清sST2蛋白水平在0 h和3 h肝细胞损伤的早期无明显差异,但在5 h肝细胞损伤的中期却显著升高,之后又显著降低。免疫组织化学染色显示急性肝衰竭小鼠肝内IL-33来源于血管内皮细胞和肝血窦细胞核内。结论 IL-33及其受体ST2随时间的动态变化与急性肝衰竭的病情进展存在紧密联系,提示IL-33/ST2轴参与了急性肝衰竭的发生发展过程。     

罗格列酮对D-氨基半乳糖联合脂多糖诱导的小鼠急性肝衰竭的保护作用

目的观察罗格列酮对D-氨基半乳糖(D-GalN)联合脂多糖(LPS)诱导的小鼠急性肝衰竭的保护作用,并研究其可能的作用机制。方法雄性昆明小鼠随机分为三组:正常组、对照组和治疗组。对照组和治疗组以D-GalN/LPS腹腔注射构建小鼠急性肝衰竭模型,正常组则相应予以生理盐水腹腔注射;治疗组于造模前2 h予以罗格列酮灌胃,正常组和对照组则相应予以生理盐水灌胃。比较各组小鼠24 h存活率,检测血清丙氨酸氨基转移酶(ALT)和天门冬氨酸氨基转移酶(AST)水平,肝组织病变程度及肝组织中肿瘤坏死因子-α(TNF-α)和天冬氨酸特异半胱氨酸蛋白酶-3(Caspase-3)mRNA的表达水平。结果治疗组小鼠24 h存活率明显高于对照组(P0.05),血清ALT、AST水平明显低于对照组(P0.05);治疗组与对照组比较,肝组织炎性细胞浸润明显减少,肝细胞以变性为主,未见明显坏死;治疗组小鼠肝组织中TNF-α、Caspase-3 mRNA表达水平明显低于对照组(P0.05)。结论罗格列酮对D-GalN/LPS小鼠急性肝衰竭有保护作用,可改善肝细胞炎症和坏死,降低急性肝衰竭的死亡率,其机制可能与罗格列酮下调TNF-α、Caspase-3的表达有关。     

多功能蛋白APE1/Ref1在肝衰竭大鼠肝细胞不同部位的表达意义

目的研究多功能蛋白酶脱嘌呤/脱嘧啶核酸内切酶(APE1/Ref1)在慢加急性肝衰竭大鼠肝细胞不同部位的表达意义。方法将30只SD大鼠随机分为对照组(n=15)和模型组(n=15)。采用四氯化碳(CCL4)联合D-氨基半乳糖(D-GalN)和内毒素(LPS)注射法制备肝衰竭模型,使用B超监测筛选成功模型。检测血清ALT、AST、总胆红素(TBIL),采用HE染色观察肝组织病理学变化,采用免疫组化和免疫印迹法检测肝组织胞浆蛋白、胞核蛋白、总蛋白APE1/Ref1的表达。结果本组实验,经B超筛选模型成功率达80%;正常对照组血清ALT、AST和TBIL水平分别为(56.5±16.0)U/L、(178.7±36.5)U/L和(3.2±0.6)μmol/L,均显著低于模型组【(620.4±347.5)U/L、(1077.7±666.1)U/L和(21.2±16.9)μmol/L,均P0.05】;免疫组化法检测模型组肝组织APE1/Ref1表达水平为(6.8±1.3)IOD,显著低于正常对照组的【(8.1±1.2)IOD,P0.05】,模型组胞浆蛋白水平为(0.91±0.08)IOD,明显高于正常对照组的【(0.18±0.01)IOD,P0.01】,而核蛋白和总蛋白水平分别为(0.71±0.01)IOD和(0.92±0.03)IOD,均明显低于正常对照组【(1.41±0.04)IOD和(1.15±0.01)IOD,P0.05】。结论慢加急性肝衰竭大鼠肝内APE1/Ref1表达呈现由细胞核内转向胞浆内表达的特征,总体表达呈下降水平。     

HMGB1在急性肝衰竭大鼠中的表达及作用

目的探讨HMGB1在急性肝衰竭大鼠肝组织和血中的变化规律及作用。方法将48只健康雌性SD大鼠按数字表随机分为对照组、模型组,每组24只,采用腹腔内注射D-Gal N（400 mg/kg）＋LPS（100μg/kg）的方法诱导急性肝衰竭,同时对照组予腹腔注射等量生理盐水。两组大鼠均在4、8、12小时时间点取血液及肝组织标本,检测血清ALT、AST水平,HE染色观察肝组织病理变化,ELISA法检测血清HMGB1浓度,RT-PCR法检测肝组织HMGB1 m RNA表达,免疫组化法检测肝组织HMGB1的表达。结果 D-Gal N（400 mg/kg）＋LPS（100μg/kg）的方法能成功诱导急性肝衰竭模型。对照组血清HMGB1浓度及肝组织HMGB1 m RNA表达在各时间点均较低,而模型组随时间延长而升高。对照组肝细胞核与胞浆中仅见少量HMGB1蛋白表达,模型组肝组织HMGB1蛋白表达随时间延长升高。结论急性肝衰竭时血和肝组织中HMGB1水平均随时间延长而升高,且两者变化与肝损程度正相关。     

大黄对急性肝衰竭大鼠肝细胞凋亡的影响

目的 探讨大黄对急性肝衰竭大鼠肝细胞凋亡的影响及可能机制.方法 Wistar大鼠随机分为4组:正常对照组、模型组、大黄组和促肝细胞生长素(PHGF)组.大黄组和PHGF组于造模前3d分别每天灌服大黄水煎液和皮下注射PHGF 1 ml/100 mg,正常组和模型组每天灌服0.9％氯化钠注射液1 ml/100 mg.采用D-氨基半乳糖(D-GalN)/内毒素脂多糖(LPS)腹腔注射制备大鼠急性肝衰竭模型,造模8h后开腹取大鼠肝组织作病理检查,HE染色光镜下观察大鼠肝组织病理学变化,应用TUNEL法检测肝细胞凋亡情况,并应用免疫组化法分别检测肝组织中Fas、FasL和caspase-3的表达.结果 D-GαlN和LPS可引起严重的急性肝坏死并有广泛的肝细胞凋亡,伴Fas、FasL和caspaSe-3在肝细胞中强烈表达,大黄能减轻肝组织损伤,并可降低肝细胞凋亡及Fas、FasL和caspase-3表达(P均＜0.05).结论 大黄可抑制急性肝衰竭大鼠肝细胞凋亡,其机制可能与减轻肝细胞Fas、FasL和caspase-3表达有关.     

高脂血症大鼠肝脏内C-反应蛋白的基因表达

目的研究高脂血症大鼠血清中C-反应蛋白（CRP）、总胆固醇（TC）、甘油三酯（TG）的含量变化和血清CRP水平与肝组织CRP mRNA及蛋白的表达的相关性。方法将体重200g左右SD大鼠随机分成：对照组、高脂血症模型组2组,每组6只,对照组给予普通饮食,高脂血症模型组喂饲高脂饮食。在喂饲6、12w时分别采取各组大鼠的尾静脉血检测血清CRP与TC、TG的含量。12w后采用Realtime-PCR法、Western印迹法检测大鼠肝脏CRP mRNA及蛋白的表达水平。结果在饲养6w时模型组大鼠血清CRP、TC、TG含量明显高于对照组（P〈0.01）;模型组随着建模时间的延长各指标持续增高,12w后显著高于对照组（P〈0.01）;12w后大鼠肝脏CRP mRNA及蛋白表达量,模型组均较对照组明显升高（P〈0.05,P〈0.01）。结论高脂血症大鼠血清中CRP含量升高,其机制与大鼠肝脏CRP mRNA及蛋白表达量升高有关。     

Urotensin Ⅱ在急性肝衰竭小鼠肝组织中的表达及损伤作用

目的:探讨Urotensin Ⅱ(UⅡ)在急性肝衰竭(acute liver failure,ALF)小鼠肝组织中的表达及损伤作用.方法:♂Balb/c小鼠随机分成4组(每组6只):正常对照组(A组)、预处理对照组(B组)、模型组(C组)和预处理模型组(D组).模型动物以脂多糖(lipopolysaccharide,LPS)/D-半乳糖胺(D-galactosamine,D-GalN)腹腔注射,预处理动物在造模前30min,用UⅡ受体拮抗剂Urantide0.6mg/kg尾静脉注射.LPS/D-GalN攻击12h后,采集血清和肝组织标本,并观察24h小鼠存活情况;采用Reitman-Frankel法检测血清丙氨酸氨基转移酶(alanine aminotransferase,ALT)和天冬氨酸氨基转移酶(aspartate amino-transferase,AST)活性水平;采用HE染色显微镜观察肝组织损伤程度;RT-PCR法检测UⅡ及其受体UTmRNA的表达;ELISA法检测血清UⅡ多肽分泌水平;免疫组织化学方法检测肝组织UⅡ多肽及其UT受体蛋白质表达.结果:C组小鼠死亡率为66.7%,A、B和D组所有动物均存活;LPS/D-GalN攻击引起C和D组小鼠血清ALT和AST水平显著升高(P<0.01),而D组较C组显著降低(2271.09U/L±102.24U/Lvs1160.67U/L±258.32U/L,1569.42U/L±204.04U/Lvs1030.31U/L±108.09U/L,P<0.01);C组小鼠肝组织结构破坏明显,见大片出血性坏死及炎症表现,D组肝组织结构保持完整,仅有局灶性出血坏死,炎症明显减轻;C和D组小鼠血清UⅡ多肽水平较A和B组高(P<0.01),但D组较C组明显降低(3.73g/L±0.52g/Lvs1.90g/L±0.27g/L,P<0.01);LPS/D-GalN诱导了C和D组小鼠肝组织UⅡ和UT的mRNA及蛋白质高水平表达,而D组的表达水平较C组显著降低(P<0.01).结论:LPS/D-GalN可诱导ALF小鼠肝组织表达和分泌UⅡ,并促进肝组织UT受体的表达;UⅡ的表达与分泌可能存在正反馈调控机制;UⅡ/UT受体介导了LPS/D-GalN诱导的ALF的发生.     

Pim-3基因抑制暴发性肝细胞凋亡的机制

目的 探讨Pim-3基因对暴发性肝细胞凋亡的抑制机制. 方法 32只大鼠随机分成4组(8只/组).A组为正常对照组,B、C组和D组采用流体力学注射方法,分别以林格氏液、空载体质粒pEGFP-N2和重组质粒pEGFP-N2/Pim-3溶液预处理大鼠;1 d后,予脂多糖(LPS) /D-半乳糖胺(D-GalN)腹腔注射诱导暴发性肝细胞凋亡.8h后处死大鼠,采集肝组织标本.用Caspase-3活性测定法检测细胞凋亡情况;RT-PCR检测肝组织诱导型一氧化氮合酶(iNOS)、p53基因表达水平;Western blot检测肝组织Bcl-2、Bax蛋白表达水平.组间数据比较采用非参数Kruskal-Wallis检验.结果 LPS/D-GalN联合攻击造成了大鼠肝内Caspase-3活性显著增高,而D组Caspase-3活性较B组和C组均显著降低[(141.7±13.7)RFU比(508.1±32.0)、(493.5±33.1)RFU,P值均＜0.01].LPS/D-GalN的应用也诱导了肝组织iNOS mRNA、p53 mRNA、Bax蛋白表达,与B组和C组相比,D组iNOS mRNA和p53 mRNA的表达水平显著降低(0.06±0.01比0.42±0.08、0.35±0.06;0.73±0.11比1.17±0.25、1.23±0.31,P值均＜0.01),而Bax蛋白表达水平差异无统计学意义(1.19±0.09比1.13±0.08、1.25±0.11,P＞0.05);另外,D组肝内Bcl-2蛋白表达水平较A、B组和C组均显著升高(3.05±0.29比1.03±0.05、0.98±0.06、1.10±0.08,P值均＜0.01).结论 Pim-3基因通过对损伤基因和凋亡相关基因的影向抑制了暴发性肝细胞凋亡的发生.     

抗肝衰复方对急性肝衰竭大鼠高迁移率族蛋白-1和增殖细胞核抗原表达的影响

目的:观察抗肝衰复方对急性肝衰竭大鼠肝组织高迁移率族蛋白-1(HMGB1)和增殖细胞核抗原(PCNA)的影响,探讨抗肝衰复方对大鼠急性肝衰竭的作用机制.方法:健康雄性Wistar大鼠110只,随机分为正常组10只、模型组20只、促肝细胞生长素(PHGF)对照组20只、茵陈蒿汤(YCHT)组20只、抗肝衰复方小剂量组20只、抗肝衰复方大剂量组20只.除正常组外其余各组分别给予D-氨基半乳糖(D-GalN)800mg/kg和内毒素脂多糖(LPS)0.1mg/kg的剂量,腹腔注射1次成模.正常组给予等量生理盐水腹腔注射.各组均于造模后2小时用药,按每次1.5mg/100g,每天2次灌胃.模型组和正常组均分别按1.5ml/100g灌服生理盐水,2次/d,连用3天.造模后72小时取材.观察造模后72小时内大鼠病死率.检测血清丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)与总胆红素(TBil)含量.HE染色观察肝组织病理变化,蛋白印迹法分析肝组织HMGB1表达,免疫组织化学染色法检测肝组织PCNA蛋白表达.结果:抗肝衰复方大剂量组病死率及血清ALT、AST、TBil含量降低;肝细胞坏死、炎性浸润程度显著改善;HMGB1表达水平明显降低,PCNA表达水平明显升高,与模型组相比P＜0.01或P＜0.05.结论:抗肝衰复方对急性肝衰竭大鼠模型的防护作用,可能与抑制HMGB1的释放,降低内毒素血症,促进肝组织PCNA表达有关.     

Growth hormone promotes early initiation of hepatocyte growth factor gene expression in the liver of hypophysectomized rats after partial hepatectomy.

GH accelerates hepatic regeneration in the rat. Hepatocyte growth factor (HGF), a potent hepatocyte mitogen in vitro, is considered to be a major regulator of hepatic regeneration. In the present study, the effects of GH and insulin-like growth factor-I (IGF-I) on HGF gene expression in regenerating rat liver was investigated. In hypophysectomized rats treated with GH, hepatic HGF mRNA levels were increased 3 h after partial hepatectomy and reached peak levels after 5 h. In rats with intact pituitaries and in hypophysectomized rats not given GH treatment, HGF mRNA levels in liver were unchanged during the first 5 h following hepatectomy and reached peak levels after 10-18 h. DNA synthesis in the liver of GH-treated rats increased from low levels 10 h after hepatectomy to peak levels after 18 h. In rats without GH treatment the synthesis of DNA was still low 18 h after hepatectomy and was increased after 26 h. Treatment of hypophysectomized rats with IGF-I promoted increases in hepatic HGF mRNA levels and DNA synthesis 3.5 h and 15 h after hepatectomy respectively. HGF mRNA levels were constantly lower after sham-hepatectomy than after partial hepatectomy. In summary, in hypophysectomized rats the responses of hepatic HGF gene expression and DNA synthesis to partial hepatectomy were both accelerated by treatment with GH or IGF-I.     

The clinical value of hepatocyte growth factor and its receptor—c-met for liver cancer patients with hepatectomy

BACKGROUND: To study the dynamic change of hepatocyte growth factor after hepatectomy in patients with primary liver cancer, and to analyse the prognostic value of hepatocyte growth factor and c-met for these patients. METHODS: Thirty-one consecutive patients undergoing partial hepatectomy for liver cancer were studied. Serum hepatocyte growth factor level was determined by using enzyme-linked immunosorbent assay kit before and after operation, respectively. C-met protein and MRNA expressions in cancerous and paracancerous tissues were examined by immunohistochemical and RT-PCR methods, respectively. The correlations between clinical-pathologic parameters and the expressions of hepatocyte growth factor in serum and c-met in cancerous tissues were analysed, respectively. RESULTS: Liver cancer patients had a significantly higher level of serum hepatocyte growth factor than normal controls (1.0424+/-0.498 ng/ml versus 0.685+/-0.115 ng/ml, p=0.008). Serum hepatocyte growth factor level was positively affected by tumour size, node cirrhosis, portal vein tumour thrombi, cholangiocarcinoma (including combined hepatocellular carcinoma), poorly differentiated hepatocellular carcinoma and tumour recurrence or metastases. After hepatectomy, serum hepatocyte growth factor level peaked on the third postoperative day, and then declined, but did not return to normal level on the postoperative day 10. From the preoperative day to postoperative day 10, the level of serum hepatocyte growth factor had a decrease of percent (85.33+/-10.2%) in the group with large tumours (>5 cm), but an elevation of percent (121.9+/-10.3%) in the group with small tumours (相似文献   

熊脱氧胆酸促进肝脏部分切除后肝细胞再生

目的 探讨熊脱氧胆酸（ｕｒｓｏｄｅｏｘｙｃｈｏｌｉｃ ａｃｉｄ，ＵＤＣＡ）对胆道梗阻肝脏部分切除（ＰＨ）后肝细胞再生的影响。方法Ｗｉｓｔａｒ大鼠随机分为正常７０％肝部分切除组（Ｎ－ＰＨ）、胆道梗阻２周７０％ＰＨ组（ＢＤＯ－ＰＨ）、ＢＤＯ—ＰＨ ＵＤＣＡ治疗组及ＢＤＯ—ＰＨ生理盐水治疗组。观察肝组织学改变，检测７０％ＰＨ后肝细胞ＢｒｄＵ标记、肝内肝细胞生长因子（ＨＧＦ）及其受体Ｍｅｔ ｍＲＮＡ表达。结果 ＵＤＣＡ治疗能促进胆道梗阻后肝功能好转并减轻肝组织学病变；ＵＤＣＡ治疗组大鼠７０％ＰＨ后肝内ＨＧＦ／Ｍｅｔ ｍＲＮＡ高峰表达值均高于ＢＤＯ—ＰＨ组（Ｐ ＜ ０．０５），肝细胞 ＢｒｄＵ高峰标记指数（５９．３９±１０．８２）％高于 ＢＤＯ—ＰＨ组肝细胞 ＢｒｄＵ高峰标记指数（３６．２２±８．３７％（ｔ＝４．１４９，Ｐ＜０．０１），而与Ｎ－ＰＮ组肝细胞ＢｒｄＵ高峰标记指数（６８．６４±１１．２６％）％相比差异无显著性（ｔ＝１．４５１，Ｐ＞０．０５）。结论 ＵＤＣＡ通过缓解胆道梗阻后肝组织损害并上调７０％ＰＨ后肝内ＨＧＦ／Ｍｅｔ ｍＲＮＡ表达，从而促进胆道梗阻肝脏部分切除后肝细胞再生。     

Hepatocyte growth factor as well as vascular endothelial growth factor gene induction effectively promotes liver regeneration after hepatectomy in Solt-Farber rats

BACKGROUND/AIMS: Hepatic oval cells play an important role in liver regeneration when proliferation of mature hepatocytes is inhibited. The aim of this study was to examine the effect of hepatocyte growth factor (HGF), or vascular endothelial growth factor (VEGF) on proliferation of oval cells in the Solt-Farber rat model. METHODOLOGY: One hour after 70% partial hepatectomy, 2-acetyl-aminofluorene-induced damaged rats were infected intravenously with recombinant adenoviral vectors, encoding rat HGF or human VEGF, or Escherichia coli beta-galactosidase as a control. RESULTS: The plasma HGF concentrations in the HGF-transferred rats were elevated compared with the other groups at 4 and 7 days after hepatectomy. Oval cells were confirmed by positive staining of both cytokeratin-19 and alpha-fetoprotein. Oval cells around the portal tracts in the HGF or VEGF-transferred rats increased in number compared with the control rats at 7 and 9 days after hepatectomy. The proliferating cell nuclear antigen labeling indices of oval cells and the hepatic regeneration rate after hepatectomy were significantly augmented by the HGF or VEGF treatment. Moreover, cyclin E expression was elevated in the HGF-treated rats. CONCLUSIONS: In the Solt-Farber rat model, HGF or VEGF gene injection effectively promoted liver regeneration after hepatectomy mainly with increased proliferation of hepatic oval cells.     

Expressions of molecules associated with hepatocyte growth factor activation after hepatectomy in liver cirrhosis

BACKGROUND/AIMS: The activation pathway of hepatocyte growth factor (HGF), including HGF activator (HGFA) and HGFA inhibitor-1, 2 (HAI-1, 2), has recently been clarified. The present study examined mRNA expressions of HGF, HGFA and HAI-1 following partial hepatectomy in normal and cirrhotic rats. METHODOLOGY: Liver cirrhosis was induced by intraperitoneal injections of dimethylnitrosamine. Two weeks after, the cirrhotic and normal rats underwent 70% hepatectomy and the liver regeneration rate, DNA synthesis of hepatocytes, plasma HGF level, and mRNA expressions of HGF, HGFA, and HAI-1 in the liver, spleen, and lung were examined at different times. RESULTS: Liver regeneration in the cirrhotic rats was deteriorated with a later peak of hepatocellular DNA synthesis. Hepatic HGF mRNA and splenic HAI-1 mRNA were upregulated and liver HGFA mRNA was downregulated in the cirrhotic rats. CONCLUSIONS: Insufficient HGF activation both by a reduced expression of hepatic HGFA and an increased expression of splenic HAI-1 may be one of the reasons for the impaired liver regeneration in cirrhosis.     

Identification and characterization of "injurin," an inducer of expression of the gene for hepatocyte growth factor.

The marked and rapid increase of hepatocyte growth factor (HGF) mRNA in the intact lung of rats after partial hepatectomy or unilateral nephrectomy suggests the existence of a humoral factor mediating a signal of injury to distal organs and may induce the expression of HGF gene in these organs. We have now identified a proteinous factor in the sera of rats with injury of liver or kidney that increases HGF mRNA in the intact lung. When the serum of rats with liver insult caused by partial hepatectomy or ischemic treatment was injected i.p. into normal noninjured rats, it induced a marked HGF mRNA expression in the lung of the recipient rats. The addition of serum from rats with various hepatic or renal injuries to MRC-5 human embryonic lung fibroblasts in culture also led to the induction of HGF mRNA expression, so that the production of HGF by MRC-5 cells after treatment with the sera was remarkably increased in the culture medium. However, serum from the normal intact rat induced no HGF production and no HGF mRNA in the lung in vivo and lung fibroblasts in vitro. This factor, which increases HGF production, was purified greater than 200-fold from sera of CCl4-treated rats. The factor proved to be an acid- and heat-stable protein with an apparent molecular mass of 10-20 kDa in SDS/PAGE. Its activity markedly increased within 3-6 hr in the plasma of rats after various treatments that injured the liver or kidney. These results suggest that the factor specifically appears in the blood of rats with organ injury and may be involved in organ regeneration through the potential to increase the synthesis of HGF. Since the factor seems to mediate various organ injuries, we named it "injurin."     

Functional expression of HGF and its receptor in human colorectal cancer

BACKGROUND: Hepatocyte growth factor (HGF) stimulates proliferation, migration and morphogenesis of epithelial cells by specific binding to its receptor c-met. Overexpression of HGF or c-met has been reported for human gastric or pancreatic cancer. In colorectal cancer overexpression of c-met but not HGF has been shown. However, elevated HGF serum levels have been detected in colorectal cancer patients. Therefore, the present study was performed to investigate expression patterns of both c-met and HGF in colorectal cancers and metastasis in comparison to normal mucosa. Furthermore, the mitogenic actions of HGF on colorectal cancer cells were studied in vitro. METHODS: Expression of c-met and HGF were analyzed by RT-PCR and Western blotting and localized in the tissues utilizing immunohistochemistry. Mitogenic effects of HGF were determined in four human colon cancer cell lines by (3)H-thymidine incorporation studies. RESULTS: C-met and HGF mRNA were detectable in 60% of the normal specimen, but in the majority of cancer samples, and in just 33% of the liver metastasis. In cancer samples a coexpression of c-met and HGF was detected in 77% of the specimens. The extent of protein expression of receptor and ligand correlated with the mRNA expression. Moreover, c-met protein expression was increased 2- to 3-fold in colorectal cancers. C-met was detected in cells of epithelial origin, whereas HGF was expressed by mesenchymal cells. In vitro, HGF significantly stimulated cell growth in all four cell lines. CONCLUSION: Overexpression of c-met protein in colorectal cancers is combined with an expression of HGF in the majority of cases suggesting a paracrine manner of growth enhancement, while only a weak expression of c-met or HGF was detected in metastatic tissues.