肝癌细胞中connexin32、connexin43的表达及其与间隙连接通讯功能的相关性

目的：研究肝细胞肝癌和正常肝细胞间隙连接蛋白connexin32（Cx32)、connexin43(Cx43）的表达，及其对间隙连接通讯功能（GJIC）的影响。方法：应用应用培养及流式细胞分析技术（FCM），研究肝癌细胞系HHCC、SMMC－7721和正常肝系QZG细胞中Cx32和Cx43的表达。结合Ｌucifer Yellow划痕标记荧光传输技术（SLDT），检测上述细胞的间隙连接通讯功能。结果：流式细胞仪分析证实，Cx32蛋白在肝癌细胞系HHCC、SMMC－7721和正常肝细胞系QZG细胞中表达的阳性率分别为1．9％、0．7％和99．0％；Cx43蛋白在HHCC、SMMC－7721和QZG细胞中表达的阳性率分别为7．3％、26．5％和99．1％。SLDT检测发现肝癌细胞HHCC，SMMC－7721的间隙连接通讯功能较正常肝细胞QZG明显减弱。结论；Cx3、Cx43蛋白在正常肝细胞中具有较高水平的表达，在肝癌细胞中表达水平显著降低，肝癌细胞的间隙连接通讯功能较正常肝细胞亦明显减弱。Cx32、Cx43表达调控异常引起的间隙连接通讯障碍可能与肝癌的发生密切相关。     

肝癌细胞增殖受M-CSF胞内和胞外自分泌的双重调控

目的：研究胞内M-CSF及其受体在肝癌SMMC 7721细胞的表达与性质,探讨胞内M-CSF对SMMC 7721细胞增殖的影响及其机制。 方法： 以高表达M-CSF的人肝癌细胞系（SMMC 7721细胞）为模型，以免疫组化、流式细胞计数、反义技术与蛋白印迹等方法观测胞内M-CSF对SMMC 7721细胞增殖的影响及其机制。 结果： M-CSF 及其受体主要在SMMC 7721细胞的胞质、胞核中表达，胞内的M-CSF的相对分子量为20 000，M-CSFR的相对分子量为120 000；免疫共沉淀分析证明M-CSF在细胞内与M-CSFR以复合物的形式存在；M-CSF的单克隆抗体及其反义寡聚核苷酸能抑制SMMC 7721细胞的增殖、下调cyclinD1/E的表达和上调p16的表达，且M-CSF的单克隆抗体及其反义寡聚核苷酸的联合使用能进一步加强对SMMC 7721细胞抑制作用和增加下调cyclinD1/E和上调p16的表达幅度。 结论： SMMC 7721细胞受M-CSF胞外自分泌和胞内自分泌的双重调控。     

血管内皮生长因子受体-1促进肝癌细胞侵袭和转移的初步研究

目的 检测不同转移潜能的肝癌细胞中有无血管内皮生长因子受体-1(VEGFR-1)及其配体(VEGF)的表达以探讨VEGFR-1在肝癌侵袭转移中的作用.方法 分别用RT-PCR、ELISA和/或Western blot法检测四种肝癌细胞株MHCC97-H、MHCC97-L、SMMC 7721和HepG 2有无VEGFR-1 mRNA和蛋白表达,用VEGFR-1的特异性配体VEGF-B处理MHCC97-H细胞以研究VEGFR-1活化对肝癌细胞迁移、侵袭和增殖等的影响.结果 MHCC97-H、MHCC97-L和SMMC 7721有VEGFR-1 mRNA和蛋白表达,但4种肝癌细胞都有VEGFR-1的配体VEGF-A和VEGF-B的表达;VEGFR-1活化能促进肝癌细胞MHCC97-H侵袭和迁移;VEGFR-1依赖的侵袭和迁移能被VEGFR-1的中和抗体18F1阻断,VEGFR-1活化不能促进细胞增殖和存活.结论 VEGFR-1及其配体的表达与肝癌细胞的侵袭转移有关,肝癌中的VEGF过表达可以自分泌的方式激活表达VEGFR-1的肝癌细胞,VEGFR-1及其配体可能是防治原发性肝癌侵袭转移的新靶点.     

胰岛素对人肝癌HepG2细胞体外诱导人脐静脉内皮细胞血管形成能力的影响

目的:探讨胰岛素对人肝癌细胞系HepG2体外诱导人脐静脉内皮细胞(HUVECs)血管形成能力的影响及其可能机制。方法:用含不同浓度胰岛素的完全培养基预培养肝癌细胞系HepG2制备条件培养基;应用预铺Matrigel基质胶的Transwell小室检测不同组条件培养基对HUVECs迁移能力的影响;运用CCK-8方法及EdU细胞增殖实验检测不同组条件培养基对HUVECs增殖能力的影响;运用内皮细胞成管实验检测不同组条件培养基对HUVECs成血管能力的影响;同时应用RT-PCR检测不同胰岛素浓度培养的HepG2细胞中血管内皮生长因子(VEGF)121、VEGF165、环氧化酶2(COX-2)的转录水平。结果:在一定浓度范围内,HepG2细胞对HUVECs的侵袭迁移能力、增殖能力的影响,对HUVECs的成血管能力的影响,对HepG2细胞VEGF121、VEGF165、COX-2转录水平的影响,均分别与胰岛素浓度呈正相关。结论:在一定浓度范围内,胰岛素可能通过上调HepG2细胞中VEGF121、VEGF165、COX-2的表达水平促进HepG2细胞诱导HUVECs血管形成能力。     

Caveolin-1反义寡核苷酸对SMMC7721细胞增殖和VEGF表达的影响

目的:研究caveolin-1反义寡核苷酸对肝癌细胞增殖和血管内皮生长因子(VEGF)表达的影响。方法:脂质体介导caveolin-1反义寡核苷酸瞬时转染SMMC7721细胞,Western blotting检测转染效果;MTT法和ELISA法分别检测转染前后SMMC7721细胞增殖和分泌VEGF的变化。结果:转染48 h后,反义寡核苷酸组caveo-lin-1蛋白表达水平明显低于对照组;MTT检测结果显示,转染后的SMMC7721细胞显著增殖,增殖率为90.9%;ELISA检测结果显示,转染后的SMMC7721细胞分泌的VEGF显著升高(P0.01)。结论:Caveolin-1反义寡核苷酸抑制caveolin-1的表达,而caveolin-1具有抑制SMMC7721细胞的增殖和其分泌VEGF的作用,有望成为肿瘤治疗的新靶点。     

CD133和CD34在肝细胞癌血管生成拟态形成中的表达及意义

背景：在恶性肿瘤中血管生成拟态的形成过程与肿瘤干细胞有密切联系。 目的：分析肝癌干细胞标志物CD133和CD34在肝细胞癌血管生成拟态形成中的表达及意义。 方法：建立肝癌细胞HCC97H、SMMC7721和正常肝细胞L02三维培养体系,结合激光捕获显微切割技术分离形成血管生成拟态的肝癌细胞,分别利用RT-PCR和Western blot技术检测CD133和CD34表达水平。 结果与结论：三维培养条件下,肝癌细胞HCC97H细胞形成血管生成拟态,肝癌细胞SMMC7721以及正常肝细胞L02未形成血管生成拟态。形成血管生成拟态的肝癌细胞HCC97H中CD133、CD34在mRNA及蛋白表达水平上均高于未形成血管生成拟态的肝癌细胞SMMC7721和正常肝细胞L02(P < 0.05)。表明高侵袭性肝癌细胞在三维培养下形成血管生成拟态,而低侵袭性肝癌细胞及正常肝细胞不能形成血管生成拟态;肝癌细胞形成血管生成拟态的过程中与表达肝癌干细胞有关。     

肝癌肿瘤微环境对血管内皮细胞增殖及血管生成能力的影响

研究间接共培养条件下肝癌细胞培养基对血管内皮细胞增殖及血管生成能力的影响,初步探讨肿瘤微环境下血管新生的分子机制。体外培养人脐静脉内皮细胞株EA.hy926,与肝癌细胞株HepG2条件培养基进行共培养;四甲基偶氮唑盐(MTT)法检测肝癌细胞条件培养基对血管内皮细胞增殖的影响;血管管腔形成实验检测血管内皮细胞的血管生成能力。Western blot测定肝癌细胞条件培养基对血管内皮EA.hy926细胞血管内皮生长因子(VEGF)及其受体Flk-1表达的影响。结果表明,EA.hy926细胞经HepG2条件培养基处理后,其增殖能力明显增加。接种于Matrigel胶的EA.hy926细胞经HepG2条件培养基刺激后,形成管腔数目增加,成血管能力明显增强;同时,其胞内VEGF及其受体Flk-1的表达呈时间依赖性上调。肿瘤微环境下肝癌细胞作用于血管内皮细胞,可促进血管内皮细胞的增殖并提高其血管生成能力。     

ING4基因真核表达载体的构建及其功能

目的：构建真核表达载体pcDNA3.0-ING4,观察ING4基因对人肝癌SMMC7721细胞周期及凋亡的影响。方法：小鼠肝组织经RT-PCR扩增,构建真核表达载体pcDNA3.0-ING4,分别用双酶切、PCR、基因测序进行鉴定,将其转导进入人肝癌SMMC7721细胞,检测ING4基因的表达情况及其对细胞周期的影响,应用荧光显微镜和激光扫描共聚焦显微镜观察细胞凋亡情况。结果：RT-PCR产物为约750bp的条带,基因测序正确,转导进入人肝癌细胞株SMMC7721后可延长G2期,其凋亡率（23.66％）明显高于对照组（13.75％）。结论：成功分离得到了小鼠ING4基因并成功构建真核表达载体pcDNA3.0-ING4,该质粒转染人肝癌SMMC7721细胞后可延长G2期并可促使细胞凋亡。     

肝癌细胞间隙连接蛋白Cx32,Cx43的流式细胞仪分析

细胞间隙连接（gspjunction）基因是最近发现的另一类非突变型抑癌基因”’。通过该基因表达的蛋白产物一间隙连接蛋白（co。exin，Cx）所构成的间隙连接通道，进行相邻细胞间能量和信息的传递，在细胞生长、分化控制中起重要的作用“’。同时，CX表达的降低与多种肿店的形成及恶性程度相关”’。我们对其中CX32，Cx43与肝癌细胞发生的关系进行了研究。l材料和方法1．l细胞系人肝癌细胞系HHCC，SMMC－7721及正常人肝细胞系QZG，由中国科学院上海细胞生物所提供。以含100ml／L热灭活胎牛血清（美国Gibco公司）、IXI0iii／L青霉素及…     

蛋白激酶CβⅡ诱导上皮-间质转化及血管新生促进肝癌发展

目的 探讨蛋白激酶CβⅡ（PKCβⅡ）在肝细胞癌(HCC)发展中的作用机制。方法 免疫印迹法观察PKCβⅡ在肝细胞系L02和肝癌细胞系SK-hep1、HepG2、BEL-7404、7721、Hep3B和huh7中的表达，构建稳定高表达PKCβⅡ的细胞系，倒置相差显微镜下观察细胞形态变化，免疫荧光观察E-钙黏蛋白（E-cadherin）、N-钙黏蛋白（N-cadherin）表达的变化；通过免疫印迹法、实时定量聚合酶链反应(Real-time PCR)和放线菌酮（CHX）追踪实验，观察PKCβⅡ调控E-cadherin、N-cadherin和Snail表达的分子机制；小室迁移和侵袭实验(transwell assay)以及裸鼠尾静脉注射观察PKCβⅡ对肝癌细胞转移的影响；成管实验观察PKCβⅡ对人脐静脉内皮细胞（HUVECs）血管形成能力的影响，酶联免疫吸附法（ELISA）观察PKCβⅡ对肝癌细胞上清中血管内皮生长因子A（VEGFA）含量的影响。结果 PKCβⅡ在肝癌细胞系中的表达高于肝细胞系L02，PKCβⅡ促进肝癌细胞形态从鹅卵石样上皮细胞向梭行间质样细胞的转变，通过mRNA水平下调E-cadherin（P<0.05）和上调N-cadherin（P<0.01）的蛋白表达，通过翻译水平上调Snail蛋白表达，PKCβⅡ还促进了肝癌细胞的迁移、侵袭（P<0.01）以及VEGFA的分泌（P<0.01）和血管新生（P<0.01）。结论 蛋白激酶CβⅡ诱导上皮-间质转化及血管新生在肝癌的发展中有重要作用。     

HAb18G/CD147拮抗肽对肝癌细胞表面抗原HAb18G的亲和性

目的：研究HAb18G／CDl47拮抗肽对肝癌细胞上HAb18G／CDl47抗原的亲和性。方法：利用流式细胞仪测定人肝癌细胞(HHCC，SMMC7721)上HAbl8G抗原的表达。分别在HAb18G／CDl47拮抗肽AP—1、AP—2和AP-6的N端标记生物素，用流式细胞仪和激光共聚焦显微镜测定AP—1、AP—2和AP-6与HHCC或SMMC7721的结合能力。结果：HAbl8G抗原在HHCC和SMMC7721细胞上均呈高表达。AP-6对HHCC的亲和力最强，AP—2次之，AP—1最弱。AP-6对与SMMC7721的亲和力也最强，AP—1次之，AP—2末检测到。结论：HAb18G／CDl47拮抗肽对肝癌细胞表面抗原HAb18G／CDl47具有较高的亲和性。     

Microvessel density, vascular endothelial growth factor and its receptors Flt-1 and Flk-1/KDR in hepatocellular carcinoma.

Assessment of angiogenesis may yield important information for an effective antiangiogenic treatment for hepatocellular carcinoma (HCC) because HCC is characteristically hypervascular We examined the relationship of microvessel density (MVD), vascular endothelial growth factor (VEGF), and VEGF receptors Flt-1 and Flk-1/KDR in 50 patients with HCC and in 3 hepatoma cell lines. VEGF messenger RNA (mRNA) was overexpressed in 26 tumors (52%), and the 3 VEGF isoforms (121, 165, and 189) were present in high frequencies. Flt-1 mRNA was overexpressed in 34 tumors (68%), with levels significantly increased in HCCs compared with the nontumorous livers. Tumor Flt-1 mRNA significantly correlated with tumor VEGF mRNA levels. Within the group of tumors 8.5 cm or less in diameter, tumors with intrahepatic metastasis in the form of tumor microsatellite formation had significantly higher VEGF mRNA levels. MVD assessed by immunohistochemical analysis with CD34 antibody was inversely related to tumor size. Angiogenesis as assessed by MVD and tumor VEGF expression seems to have a more important role in tumor growth and intrahepatic metastasis in smaller HCCs. The differential up-regulation of Flt-1 suggests that it may have an important role in angiogenesis in HCC.     

Vascular endothelial growth factor is an autocrine growth factor in human malignant mesothelioma

Vascular endothelial growth factor (VEGF), a potent mitogen for vascular endothelium, is expressed in malignant pleural mesothelioma (MM). The present report examines the effect of VEGF on MM growth. Four MM cell lines produced significantly higher VEGF levels than normal mesothelial cells (1946+/-14 pg/ml vs. 180+/-17 pg/ml; p<0.001). In addition, MM cells expressed the tyrosine kinase-related VEGF receptors Flt-1 and KDR. Recombinant human VEGF phosphorylated both Flt-1 and KDR and increased proliferation of all four MM cell lines in a dose-dependent fashion. Neutralizing antibodies against either VEGF, Flt-1 or KDR significantly reduced MM cellular proliferation. In addition, expression of VEGF, Flt-1, and KDR was observed in MM biopsies. Moreover, higher VEGF levels were found in the pleural effusions of MM patients than in the effusions of patients with non-malignant pleural disease (1885.7+/-894.9 pg/ml vs. 266.9+/-180.5 pg/ml; p<0.001). Linear regression analysis showed a significant inverse correlation between serum VEGF levels and MM patient survival (r=0.72; p<0.01). No correlation was found between tumour vessel density and either serum (r=0.26; p=0.42) or pleural effusion (r=0.35; p=0.26) VEGF levels. These results indicate that VEGF, via activation of its tyrosine kinase receptors, may be a key regulator of MM growth. In addition, VEGF production could have an impact on patient survival, not only by promoting tumour angiogenesis but also by directly stimulating tumour growth.     

Expression of vascular endothelial growth factor,placental growth factor,and their receptors Flt-1 and KDR in human placenta under pathologic conditions

The vascular endothelial growth factor (VEGF) family and its receptors have multifunctional activities besides angiogenesis, and some of these molecules are induced by hypoxia/ischemia. They are known to be expressed in human placenta, but little is known about their involvement in pathologic conditions. We have investigated the expression patterns of VEGF, placental growth factor (PlGF), and their receptors fms-like tyrosine kinase (Flt-1) and kinase insert domain-containing region (KDR) in placentas with histopathological changes. Forty-two placentas from normal and complicated pregnancies delivered in the second and third trimesters were fixed with paraformaldehyde and embedded in paraffin. In situ hybridization and immunohistochemistry were performed on serial sections. In the villi with characteristic hypoxic/ischemic changes (HIC), including increased syncytial knots, infarction, or hypercapillarization, intense immunostaining for VEGF was detected in the media of blood vessels, and increased staining for KDR was demonstrated in the endothelial cells. Strong PlGF immunoreactivity was localized to the degenerative trophoblasts around the infarctions. Marked Flt-1 mRNA expression in the syncytiotrophoblast layers of HIC villi was identified, but some samples did not show ligand expression in these regions. Positive immunostaining for VEGF, PlGF, and Flt-1 was observed in infiltrated neutrophils and macrophages in the placentas with chorioamnionitis (CAM). These findings suggested that in the hypoxic/ischemic regions, VEGF and KDR expression is increased within the villous vessels by paracrine regulation, whereas the expression of PlGF and Flt-1 is enhanced in villous trophoblasts by autocrine regulation. The Flt-1 gene may also be up-regulated directly by hypoxia/ischemia independently of ligand mediation. Furthermore, the results indicated that VEGF and PlGF stimulate inflammatory cell migration by autocrine regulation via the Flt-1 receptor in the CAM placenta. Thus, various functions of VEGF family members participate in the development of pathologic changes in the placenta.     

Expression of vascular endothelial growth factor and its receptors correlates closely with formation of the plexiform lesion in human pulmonary hypertension

The pulmonary vasculature exhibits various morphological changes in patients with pulmonary hypertension (PH). Among them, the plexiform lesion is one of the most characteristic vascular lesions, although nothing is known about the molecular mechanisms of its formation. In the present study, the expression of vascular endothelial growth factor (VEGF), an endothelial cell-specific angiogenic mitogen, and its receptors, fms-like tyrosine kinase (Flt-1) and kinase insert domain-containing receptor (KDR), in the lungs of five cases with PH, were examined. By in situ hybridization, VEGF expression was found in modified smooth muscle cells inside the plexiform lesions as well as in medial smooth muscle cells of the arteries adjacent to the lesions. The expression of Flt-1 mRNA was observed in endothelial cells of the arteries adjacent to the plexiform lesions, while KDR mRNA was expressed in the endothelial cells inside the plexiform lesions. VEGF was immunolocalized to the endothelial cells expressing its receptors as well as the modified smooth muscle cells producing VEGF. These results demonstrate that VEGF and its receptors are upregulated with a close correlation to the plexiform lesions, and suggest that VEGF expressed by smooth muscle cells may activate the endothelial cells to form the plexiform lesions.     

维生素D3受体mRNA在肝细胞增殖和肝癌发展中的作用

目的：探讨维生素D3受体mRNA在肝细胞增生和肝癌发展中的作用。方法：体外培养肝癌细胞株SMMC－7721和HCC－T细胞，培养时添加1000nmol/L、100nmol/L、10nmol/L 1，25-(OH)2D3作用1、3、6天后，用四唑盐比色试验（MTT）检测细胞的存活和生长；用反转录PCR（RT－PCR）检测维生素D3受体mRNA的表达。结果：1.25-(OH)2D3可以抑制维生素D3受体mRNA表达阳性的SMMC－7721细胞增生并且有剂量效应关系；对维生素D3受体mRNA表达阴性的HCC－T细胞没有抑制作用。9例肝癌组织标本维生素D3受体mRNA表达均为阳性。结论：1，25－（OH）2D3对于人肝癌细胞株SMMC－7721的增殖具有显著的抑制作用，其机械可能是通过维生素D3受体来实现的。     

AFP增强子驱动的HSV-TK/GCV自杀基因系统对肝癌细胞杀伤的实验研究

目的探讨人AFP增强子驱动的单纯疱疹病毒胸苷激酶/丙氧鸟苷（HSV-TK/GCV）自杀基因系统体外靶向杀伤肝癌细胞效应。方法构建人AFP增强子驱动的pAFP-CDNA3.1-TK自杀基因真核表达质粒,脂质体转染肝癌细胞,检测TK mRNA和蛋白表达,MTT法检测GCV对肝癌细胞的杀伤作用。结果成功构建pAFP-CDNA3.1-TK自杀基因真核表达质粒,在AFP阳性HepG2细胞中检测到TK mRNA和蛋白表达,添加GCV可特异性地杀伤HepG2细胞,而AFP阴性的SMMC7721细胞生长不受影响。结论 AFP增强子驱动的TK/GCV自杀基因系统可以靶向杀伤AFP阳性肝癌细胞。     

AFP启动子驱动的yCD/TK双自杀基因靶向杀伤肝癌细胞的体内外研究

目的： 研究携带甲胎蛋白（AFP）启动子的酵母菌胞嘧啶脱氨酶/胸苷激酶（yCDglyTK）双自杀基因体内外靶向性杀伤肝癌细胞的效果和机制。方法: 构建携带AFP启动子的yCD/TK双自杀基因表达质粒。通过阳离子脂质体将携带AFP启动子的yCD/TK双自杀基因转染HepG2和SMMC7721细胞,用MTT法测定不同浓度氟胞嘧啶（5-FC）、更昔洛韦（GCV）及联合治疗的杀伤作用,用流式细胞仪检测细胞周期。建立裸鼠肝癌皮下种植瘤模型,观察自杀基因体内杀瘤效果以及细胞凋亡的情况。结果: 成功构建的携带AFP启动子的yCD/TK双自杀基因靶向性地在AFP阳性的HepG2细胞上表达,而AFP阴性的SMMC7721细胞无表达,GCV、5-FC及两者联合可有效抑制HepG2细胞生长,随药物浓度的增高而杀伤作用增强,药物间抑瘤效果比较是GCV＋5-FC＞5-FC＞GCV,而SMMC7721细胞的生长未受影响。体内实验可见GCV、5-FC及两药联合对转染后的HepG2细胞种植瘤有明显的抑制效果,并检测到明显的细胞凋亡,而对SMMC7721细胞种植瘤的生长无影响,种植瘤内极少凋亡细胞。结论: 携带AFP启动子的yCD/TK双自杀基因能有效地靶向性地杀伤AFP阳性的肝癌细胞,细胞凋亡可能是其杀伤的重要机制之一。