肾透明细胞癌VHL基因突变与Cyclin D1过度表达的相关性

背景与目的:VHL基因突变与肾透明细胞癌发生关系密切,而CyclinD1基因通过促进细胞过度增殖,对肾透明细胞癌发生和发展起重要作用。本研究拟初步探讨肾透明细胞癌中VHL基因突变的状况及其与CyclinD1表达上升的相关性。方法:取50例肾透明细胞癌手术标本,抽提病变组织和癌周正常组织中的基因组DNA和总RNA。通过PCR扩增VHL基因各外显子序列并测序以及内切酶鉴定的方法,确定肿瘤组织中VHL基因突变的比率和具体位点。通过RT-PCR和Westernblot方法,检测相应肿瘤组织中CyclinD1的表达水平是否发生改变。结果:VHL基因序列检测结果表明,有42例(84.0%)肾透明细胞癌标本的VHL基因发生各种形式的突变,有12(24.0%)例甚至发生2种以上的基因突变。在57例VHL基因外显子突变中,1号外显子突变有17例(29.8%);2号外显子突变有26例(45.6%);3号外显子突变有14例(24.6%)。CyclinD1的表达水平在42例VHL基因发生突变的组织中均有不同程度的上升,达到正常对照组的2～10倍(3.91±1.54倍)(P<0.01),另8例表现为正常。结论:在肾透明细胞癌中存在各种VHL基因突变,导致CyclinD1过度表达。     

Mdr表达与人肾细胞癌组织学类型相关

目的:研究Mdr基因与肾细胞癌(Rcc)的关系.方法:采用免疫组织化学法检测了正常肾组织和35例Rcc组织切片.结果:Mdr表达与组织学类型相关,且表达量与肿瘤分级有关.结论:Mdr基因在Rcc发生中起重要作用.     

MN／CA9蛋白在富糖原型肾细胞癌中的表达及其意义

目的：研究ＭＮ／ＣＡ９蛋白在富糖原型肾细胞癌中的表达。方法：对正常肾组织、肾损伤、肾细胞癌及非肾性富糖原癌中ＭＮ／ＣＡ９蛋白的表达进行分析。结果：仅在肾细胞癌上可ＭＮ／ＣＡ９蛋白的表达,而其它切片中未见表达。结论：ＭＮ／ＣＡ９蛋白表达可以作为肾细胞癌,尤其是富糖原型肾细胞癌的一种肿瘤标志物,以辅助其早期诊断。     

MAGE-A3基因及其产物在肾透明细胞癌组织中的表达

目的:探讨肿瘤特异性黑色素瘤抗原(MAGE-A3)基因mRNA及MAGE-A3蛋白在肾透明细胞癌组织中的表达及其临床意义.方法:采用反转录聚合酶链反应(RT-PCR)技术检测45例肾透明细胞癌患者癌组织(新鲜标本,T1期14例,T2期12例,T3期11例,T4期8例;G1 18例,G2 15例,G3 12例)及其中10例患者癌旁组织MAGE-A3基因mRNA表达;Western-blot技术检测上述组织中MAGE-A3蛋白的表达.结果:45例肾透明细胞癌组织中,24例(53%)MAGE-A3 mRNA表达阳性,10例癌旁组织表达均阴性;21例(47%)MAGE-A3蛋白表达阳性,10例癌旁组织表达均阴性.肿瘤不同分期、不同分级之间MAGE-A3基因mRNA及MAGE-A3蛋白表达的差异均无统计学意义(Pearson χ2 检验法,P> 0.05).结论:MAGE-A3基因在肾透明细胞癌中有较高表达,可望成为肾透明细胞癌特异性免疫治疗的靶基因.     

Von Hippel-Lindau抑癌基因在散发性肾透明细胞癌中的突变及其意义

背景与目的：von Hippel-Lindau（VHL）基因是一种抑癌基因,其突变在肾透明细胞癌的发生发展中发挥重要的作用.本研究旨在了解VHL抑癌基因在中国人散发性.肾透明细胞癌中的突变特点,并探讨基因突变与肿瘤分期、病理分级等临床病理特征的关系.方法：应用聚合酶链反应（PCR）、双向测序方法检测72例散发性肾透明细胞癌患者肾癌组织及正常肾组织中VHL抑癌基因的突变情况.结果：72例肿瘤组织中检测出VHL抑癌基因突变25例,突变率为35%.其中移码突变13例,错义突变8例,无义突变3例,同义突变l例.第1外显子6例,第2外显子5例,第3外显子12例,内含子区2例.25例突变中,6例突变位于密码子157～166区域.VHL抑癌基因突变与肿瘤分期、分级等临床病理指标无关（P＞0.05）.结论：中国人散发性肾透明细胞癌中VHL抑癌基因突变率较低,突变主要位于第3外显子,该外显子区可能存在一个突变热点区域.VHL抑癌基因突变与肿瘤分期、分级等临床病理指标无关,是肾透明细胞癌发生发展的早期遗传事件.     

血管内皮生长因子与肾细胞癌

血管内皮生长因子(VEGF)在肾细胞癌组织中高表达,主要受VHL基因和组织缺氧调控,可作为判断肾细胞癌患者肿瘤进展和预后的标志物.近年来将抗VEGF靶向药物用于肾细胞癌治疗,取得良好的临床疗效.     

肾细胞癌MN/CA9蛋白的表达及其生物学意义

目的 :研究MN/CA9蛋白的表达和肾细胞癌的关系 ,探讨MN/CA9蛋白在肾细胞癌诊断研究中的应用。方法 :应用免疫组化和免疫印迹的方法 ,对正常肾组织、良性肾损害和肾细胞癌组织的MN/CA9蛋白的表达进行了分析。结果 :正常人肾组织和良性肾损害均为MN/CA9阴性 ,而在 30例肾癌中却有 2 8例为MN/CA9阳性 ,尤其是 2 6例富糖原型RCC均呈现MN/CA9强阳性。结论 :MN/CA9蛋白可作为肾细胞癌尤其是富糖原型肾细胞癌的一种标志物     

单核细胞趋化蛋白及MCP-1基因在肾细胞癌组织中的表达及临床意义

目的:探讨肾细胞癌(RCC)组织及癌旁组织中单核细胞趋化蛋白 (MCP-1)基因的表达与肾细胞癌发病机制的相关性.方法:RCC患者30例,男20例,女10例,分别取血液和肾癌组织标本.对照组30例为非肿瘤患者,男20例,女10例,取血液标本,ELISA方法测定血浆中MCP-1定量.癌旁组织标本为对照组,免疫组化方法检测MCP-1表达情况.实时RT-PCR定量检测MCP-1表达.分析RCC临床特点与MCP-1表达的关系.结果:肾癌组患者血浆中MCP-1(203.5±155.8)pg/ml较非肿瘤组(92.1±35.2)pg/ml高(P＜0.05).免疫组化显示肾癌组织中MCP-1表达阳性率为73.3%(22/30),癌旁组织中的表达阳性率为40.0%(12/30),肾癌组织中MCP-1表达阳性率明显高于癌旁,差异有统计学意义(P＜0.01).同时发现肾癌组织中MCP-1的阳性强度(++)-(+++)也明显高于癌旁组织(+).肾癌组织MCP-1总RNA和mRNA水平与癌旁组织比较差异有统计学意义(P＜0.05).结论:MCP-1基因表达上调可能在肾细胞癌的发生及转移中发挥重要作用.     

乳腺癌患者外周血清中APC基因启动子甲基化异常的检测及其意义

背景与目的:检测肿瘤患者外周血中肿瘤相关标志物是当前肿瘤研究的热点之一,恶性肿瘤患者外周血中存在游离的肿瘤相关DNA已引起肿瘤学界的极大关注,人们曾在多种肿瘤患者血清中发现与原发肿瘤相同的DNA变异.本研究以APC(adenomatous polyposis coli)基因启动子甲基化作为肿瘤标志物,探讨乳腺癌患者外周血清中游离的肿瘤相关DNA与肿瘤组织及临床病理参数的相关性.方法:采用甲基化特异性PCR(methylation specific-PCR,MSP)方法,分别检测84例乳腺癌组织、癌旁正常腺体组织及外周血清中游离DNA APC基因启动子甲基化状况.结果:84例乳腺癌组织APC基因启动子甲基化频率为45.2%(38/84),相应外周血清中同样DNA变异阳性检出率为31.0%(26/84).外周血清中DNA甲基化变异与肿瘤组织的甲基化状况显著相关(r=0.977,P=0.002).检测外周血清中APC基因甲基化的敏感性为68.4%,特异性为97.8%.肿瘤组织及外周血清中游离DNA甲基化异常与临床分期、病理类型、肿块大小及受体状况无相关性(P＞0.05).肿瘤组织未检测到甲基化患者的血清中及健康人血清中均未检测到该基因甲基化变异.结论:乳腺癌患者外周血清中肿瘤相关DNA甲基化与肿瘤组织中相同基因的变异显著相关.     

肿瘤转移抑制基因编码蛋白在癌患者外周血中的表达

目的　探讨肿瘤转移抑制基因编码蛋白在癌患者外周血细胞中的表达规律。方法　采用流式细胞术对 173例各种癌患者外周血nm2 3 +、DCC +、p16+和p5 3V +细胞检出率进行检测。结果　恶性肿瘤患者外周血nm2 3 +、DCC +和p16+细胞检出率均显著低于正常对照 (P <0 0 1或P <0 0 5 ) ,但分布各有不同 ;而p5 3V +细胞检出率显著高于正常对照组 (P <0 .0 5 )。癌转移者外周血nm2 3 +、DDC +和p16+的表达水平显著低于未转移者 (P <0 .0 1)或P <0 .0 5 ) ,而p5 3V则相反。结论　恶性肿瘤能使患者外周血细胞的肿瘤转移抑制基因抑编码蛋白表达水平出现明显异常 ,而这种异常表达与恶性肿瘤转移的关系十分密切 ;不同肿瘤患者异常表达的肿瘤转移抑制基因类型有一定的倾向性。     

Cloning of the Rat Homologue of the von Hippel-Lindau Tumor Suppressor Gene and Its Non-somatic Mutation in Rat Renal Cell Carcinomas

Recently, von Hippel-Lindau ( VHL ) gene mutations were detected in non-inherited, sporadic human renal cell carcinomas (RCs) at a high frequency. In order to determine whether or not the VHL gene is also a critical gene in rat RCs, we cloned and sequenced the rat homologue of human VHL gene and searched for mutations of the VHL gene in rat RCs. Mutations in the VHL gene were not detected in spontaneous RCs of the Eker rat model or in ferric nitrilotriacetate-induced rat RCs using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) method. These data indicate that mutation of the VHL tumor suppressor gene is not an event in rat renal carcinogenesis, at least in our present systems.     

The von-Hippel-Lindau (VHL) tumor suppressor gene is not mutated in sporadic ovarian carcinomas

The von Hippel-Lindau (VHL) tumor suppressor gene has been shown to be mutated frequently not only in neoplasms from von Hippel-Lindau disease, but also in sporadic clear cell renal carcinoma. In order to reveal the possible role of the VHL tumor suppressor gene in the development of ovarian carcinoma, a total of 71 primary sporadic ovarian carcinomas were analyzed for the presence of mutations in the exon 2 and 3 of the VHL tumor suppressor gene, using the polymerase chain reaction with single strand conformation polymorphism analysis. No mutations in the VHL gene were found in any of the tumors analyzed. This result shows that the VHL tumor suppressor gene does not play a major role in the tumorigenesis of sporadic ovarian carcinoma.     

VHL alterations in human clear cell renal cell carcinoma: association with advanced tumor stage and a novel hot spot mutation

To elucidate the role of somatic alterations for renal cancer etiology and prognosis, we analyzed 227 sporadic renal epithelial tumors for mutations and hypermethylations in the von Hippel-Lindau tumor suppressor gene VHL. Tumors were classified according to the recommendations of the Union Internationale Contre le Cancer (UICC) and the American Joint Committee on Cancer (AJCC). Somatic VHL mutations were identified by PCR, single-strand conformation polymorphism analysis, and sequencing, and hypermethylations were identified by restriction enzyme digestion and Southern blotting. Frequencies of VHL alterations were established, and an association with tumor type or tumor type and tumor stage was evaluated. VHL mutations and hypermethylations were identified in 45% of clear cell renal cell carcinomas (CCRCCs) and occasionally (3 of 28) in papillary (chromophilic) renal cell carcinomas (RCCs). Lack of VHL mutations and hypermethylations in chromophobe RCCs and oncocytomas was statistically significant (P = 0.0001 and P = 0.0004, respectively). RCCs carrying VHL alterations showed, in nine cases (12%), mutations at a hot spot involving a thymine repeat (ATT.TTT) in exon 2. Tumor staging was critical to the VHL mutation/hypermethylation detection rate in CCRCCs shown by separate evaluation of patients from medical centers in Munich, Heidelberg, and Mainz. The spectrum of pT1, pT2, and pT3 CCRCCs and the VHL mutation/hypermethylation detection rate varied among these three groups. Altogether, VHL alterations were significantly associated with pT3 CCRCCs (P = 0.009). This is the first evidence of frequent somatic VHL mutations at a particular site within exon 2 and an association of VHL mutations/hypermethylations with a standard prognostic factor.     

Hepatocyte growth factor-stimulated renal tubular mitogenesis: effects on expression of c-myc, c-fos, c-met, VEGF and the VHL tumour-suppressor and related genes.

Hepatocyte growth factor (HGF/SF) is a potent renal proximal tubular cell (PTEC) mitogen involved in renal development. HGF/SF is the functional ligand for the c-met proto-oncogene, and germline c-met mutations are associated with familial papillary renal cell carcinoma. Somatic von Hippel-Lindau disease tumour-suppressor gene (VHL) mutations are frequently detected in sporadic clear cell renal cell carcinomas (RCC), and germline VHL mutations are the commonest cause of familial clear cell RCC. pVHL binds to the positive regulatory components of the trimeric elongin (SIII) complex (elongins B and C) and has been observed to deregulate expression of the vascular endothelial growth factor (VEGF) gene. HGF/SF has similarly been reported to up-regulate expression of the VEGF gene in non-renal experimental systems. To investigate the mechanism of HGF/SF action in PTECs and, specifically, to examine potential interactions between the HGF/c-met and the VHL-mediated pathways for renal tubular growth control, we have isolated untransformed PTECs from normal kidneys, developed conditions for their culture in vitro and used these cells to investigate changes in mRNA levels of the VHL, elongin A, B and C, VEGF, c-myc, c-fos and c-met genes after HGF/SF exposure. Significant elevations in the mRNA levels of VEGF, c-myc, c-fos, c-met and elongins A, B and C, but not VHL, were detected after HGF/SF stimulation of human PTECs (P < 0.02), with a consistent order of peak levels observed over successive replicates (c-fos at 1 h, VEGF at 2-4 h, c-myc, at 4 h, followed by c-met and all three elongin subunits at 8 h). This study highlights the spectrum of changes in gene expression observed in PTECs after HGF/SF stimulation and has identified possible candidate mediators of the HGF/SF-induced mitogenic response. Our evidence would suggest that the changes in PTEC VEGF expression induced by HGF/SF are mediated by a VHL-independent pathway.