RhoC蛋白在原发性肝细胞癌中的表达

目的：观测RhoC基因蛋白在原发性肝癌中的表达，探讨其与原发性肝癌临床病理指标和预后的关系。方法：采用免疫组化法，检测43例原发性肝癌及癌旁组织标本RhoC基因蛋白表达情况，并对其中36例接受根治性手术的患者进行随访。结果：RhoC蛋白在肝癌组织中的表达明显高于癌旁组织，在多结节、低分化、包膜不完整以及有门脉侵犯的原发性肝癌组织中RhoC呈高表达，RhoC低表达的患者较高表达者的同期生存率明显增加。结论：RhoC蛋白与原发性肝癌的浸润和转移有密切关系，可以作为原发性肝癌的预后判断指标之一。     

反义RhoC基因对胆管癌QBC939细胞株基质金属蛋白酶－2的抑制作用

目的 观察反义RhoC基因对胆管癌QBC939细胞株的基质金属蛋白酶-2(MMP-2)表达的影响.方法 将反义RhoC真核表达载体转染人胆管癌细胞株QBC939,逆转录－聚合酶链反应(RT-PCR)和Western blot检测MMP-2在QBC939细胞、转染空载体的QBC939细胞(QBC939-V)、转染反义RhoC的QBC939细胞(QBC939-AS)的mRNA和蛋白相对表达量.结果 QBC939细胞MMP－2 mRNA吸光度相对值为0.588±0.074,QBC939-V细胞为0.629±0.061,两者差异无统计学意义(P＞0.05),QBC939-AS细胞MMP-2 mRNA吸光度相对值为0.286±0.097;与QBC939及QBC939－V比较,差异有统计学意义(P＜0.05).结论 反义RhoC基因能够抑制QBC939细胞株的MMP-2表达.     

反义RhoC基因对胆管癌QBC939细胞株基质金属蛋白酶-9的抑制作用

目的 探讨反义RhoC基因对胆管癌QBC939细胞株的金属蛋白酶-9(MMP-9)表达的影响.方法 通过质粒转染的方法向QBC939细胞中转染反义RhoC cDNA真核表达载体pcDNA 3.1Hyp(+)质粒,RT-PCR和Western-Blot检测MMP-9在QBC939细胞、转染空载体的QBC939细胞(QBC939-V)、转染反义RhoC的QBC939细胞(QBC939-AS)的mRNA和蛋白相对表达量.结果 对照组细胞QBC939中MMP-9 mRNA和蛋白的平均光密度值分别为(0.265±0.059)和(0.242±0.063),QBC939-V细胞中MMP-9 mRNA和蛋白的平均光密度值分别为(0.257±0.039)和(0.303±0.031),而反义RhoC cDNA质粒转染组细胞中MMP-9 mRNA和蛋白的平均光密度值分别为(0.125±0.062)和(0.095±0.043);对照组中MMP-9 mRNA和蛋白的平均光密度值均高于反义RhoC转染组,统计学分析表明在QBC939-AS组和对照组之间,MMP-9的平均光密度值差异有统计学意义(P<0.05).结论 反义RhoC基因在QBC939细胞株中可以抑制MMP-9表达.     

Farnesyl transferase inhibitor treatment of breast cancer cells leads to altered RhoA and RhoC GTPase activity and induces a dormant phenotype

Farnesyl transferase inhibitors (FTIs) were shown to be effective in modulating tumor growth in Ras‐transformed tumor cells. Recent studies have focused on Rho GTPases as putative targets of FTI action. Previously, we demonstrated that FTIs were effective in inhibiting the growth and invasiveness of RhoC GTPase‐overexpressing inflammatory breast cancer (IBC) cells however, RhoC activity was increased. In this study, we examine the mechanisms of FTI action on breast cancer cells in culture through modulation of RhoC and RhoA GTPases. We found that FTI inhibition of breast cancer cell growth was reversible and resembled what has been described for an in vitro model of tumor cell dormancy. On FTI treatment, levels of active RhoA decreased significantly, whereas levels of active RhoC increased 3.8‐fold. We studied the role of these two GTPases in a fibronectin and basic FGF‐induced model of breast cancer cell dormancy. Hypoactivation of RhoA and hyperactivation of RhoC were seen to induce morphology and growth changes consistent with tumor cell dormancy in culture. In addition, the JNK/SAPK pathway was induced on FTI treatment. A pharmacologic inhibitor of the JNK/SAPK pathway significantly reduced the number of dormant cells. This study has implications for the use of FTIs as therapeutic agents as well as potential mechanisms for breast cancer cell dormancy.     

RhoC、CXCR4基因与宫颈癌生物学行为的关系

目的:探讨宫颈癌和正常宫颈组织中RhoC、CXCR4 mRNA的表达及意义。方法:采用逆转录多聚酶链反应(RT-PCR)技术分析宫颈癌(36例)和正常宫颈组织(30例)中RhoC、CXCR4 mRNA的表达。结果:RhoC、CX-CR4 mRNA在宫颈癌中表达增高,其表达与宫颈癌的临床分期、淋巴结转移有关,而与癌细胞分化程度无关。结论:RhoC、CXCR4基因的过量表达与宫颈癌的发生发展和转移密切相关。     

胃癌中RhoC和CD44v6的表达及其临床意义

背景与目的:探讨Ras相似蛋白C(Ras homologue C,RhoC)和CD44剪接变异体v6(CD44 splice variant V6,CD44v6)在胃癌中的表达及其与临床病理因素之间的关系.材料与方法:采用免疫组化SP法检测97例胃癌组织中RhoC和CD44v6的表达情况.结果:97例胃癌组织中RhoC和CD44v6阳性率分别为77.31%(75/97)、83.50%(81/97),两者表达存在相关性(P＜0.05).RhoC和CD44v6表达均与胃癌的浸润深度和肿瘤分期有关(P＜0.05),且淋巴结转移组RhoC表达显著高于无淋巴结转移组(P＜0.05).结论:RhoC和CD44v6蛋白的过量表达是胃癌的发生发展中的频发事件,可以作为判断预后的指标之一.     

RhoC反义基因转染对人胆管癌QBC939细胞生长的抑制作用

目的　构建人 Rho C基因反义真核表达载体 ,研究 Rho C基因对胆管癌 QBC939细胞株增殖的影响。　方法　应用分子克隆技术 ,将含 Rho C基因全长开放阅读框目的片段克隆到真核载体 pc DNA 3.1/ Hyg(+)上 ,构建反义 Rho C c DNA真核表达载体 ,以脂质体转染人胆管癌 QBC939细胞。检测细胞生长曲线 ,RT- PCR检测Cyclin D1 在 QBC939细胞、转染空载体的 QBC939细胞 (QBC939- V)和转染反义 Rho C重组载体的 QBC939细胞(QBC939- AS)的 m RNA相对表达量。　结果　与 QBC939细胞及 QBC939- V细胞相比 ,QBC939- AS细胞体外生长较慢。 QBC939- AS细胞、QBC939- V细胞和 QBC939细胞的 Cyclin D1 的表达量分别为 0 .15 1± 0 .0 76 ,0 .2 96±0 .0 2 6和 0 .2 87± 0 .0 5 7;QBC939- AS细胞的 Cyclin D1 的表达量与 QBC939- V细胞及 QBC939细胞的差异有显著性 (P<0 .0 5 )。　结论　 Rho C可能通过调节 Cyclin D1 来抑制 QBC939细胞的增殖能力。     

RhoA亚家族与胃癌细胞恶性表型的关系

目的:研究RhoA亚家族成员RhoA、RhoB和RhoC对胃癌细胞恶性表型的影响。方法:系用脂质体介导法分别将编码正显性RhoA突变体(V14RhoA)与野生型RhoB(wt-RhoB)和RhoC(wt-RhoC)的真核表达载体转染入胃癌SGC7901细胞中,筛选出稳定抗性克隆,并检测转染细胞的生物学行为的变化。结果:RhoA活性增强可促进胃癌细胞的增殖,而降低对化疗药物的敏感性;上调RhoB表达抑制胃癌细胞的增殖,增强对化疗药物的敏感性;上调表达RhoC则对胃癌细胞的增殖及对化疗药物的敏感性无明显的影响,但可明显促进胃癌细胞的迁移。结论:RhoA亚家族分子参与了胃癌生长、耐药及转移等多个方面,其家族中不同分子作用不同。     

RhoC Induces Differential Expression of Genes Involved in Invasion and Metastasis in MCF10A Breast Cells

Inflammatory breast cancer (IBC) is the most deadly form of breast cancer in humans presumably due to its ability to metastasize from its inception. In our laboratory, overexpression of RhoC GTPase was observed to be specific for IBC tumors, but not for stage-matched, non-IBC tumors. RhoC is known to contribute to an IBC-like phenotype in HPV-E6E7 immortalized breast cells. To further study the effect of RhoC overexpression on IBC metastasis, we generated stable transfectants of spontaneous immortalized mammary epithelial cells (MCF10A) overexpressing wild-type RhoC or a constitutively active RhoC mutant (G14V). Both the RhoC wild type and the G14V transfectants were highly invasive and proliferated more rapidly compared to vector-only control clones. Overexpression of RhoC led to an increase in actin stress fiber and focal adhesion contact formation. Comparative microarray analysis of these clones further revealed that RhoC overexpression upregulated 108 genes whereas seven genes were down-regulated. We have further verified by quantitative RT-PCR that genes involved in cell proliferation, invasion/adhesion, and angiogenesis were modulated by RhoC. This work suggests strong candidates for the downstream oncogenic functions of RhoC.     

Validation of a Tissue Microarray to Study Differential Protein Expression in Inflammatory and Non-Inflammatory Breast Cancer

AIMS: Inflammatory breast cancer (IBC) is an aggressive subtype of breast cancer with poor prognosis. The mechanisms responsible for the aggressive clinical evolution are incompletely understood. We constructed a tissue microarray (TMA) and validated its use in translational IBC research. Differential expression of proteins that might play a role in causing the IBC phenotype was studied. METHODS AND RESULTS: A TMA containing 34 IBC and 41 non-stage matched non-IBC tumours was constructed. Five core biopsies were taken for each IBC and three cores for each non-IBC tumour. The TMA was validated using three approaches: (1) the excellent concordance between immunohistochemical results of the initial pathological examination and the results obtained with the TMA for ER, PR and HER2/neu (kappa > 0.74); (2) the known differential expression between IBC and non-IBC for four bio-markers in IBC (ER, PR, p53 and HER2/neu) was confirmed ( p < 0.01); (3) the HER2/neu status using three different antibodies (CB11, TAB250 and HercepTest) was highly concordant (kappa > 0.75). Furthermore, the overexpression of E-Cadherin and RhoC GTPase in IBC ( p < 0.05) was confirmed. We did not find a differential expression pattern for carbonic anhydrase IX (CA IX) and EGFR. CONCLUSIONS: Using different approaches, we have validated the use of our TMA for studying differential protein expression in IBC and non-IBC. We confirm the overexpression of E-Cadherin and RhoC GTPase in IBC. The lack of differential expression for CA IX and EGFR might suggest the pathways are equally utilised in both types of breast cancer.