浅表性和浸润性膀胱移行细胞癌上皮钙黏素基因启动子C/A单核苷酸多态性的比较

目的 比较浅表性和浸润性膀胱移行细胞癌上皮钙黏素基因启动子近侧-160位点C/A单核苷酸多态性.方法 浅表性和浸润性膀胱移行细胞癌各33例17例.从血液中提取人基因组DNA,PCR扩增包含E-cad基因启动子近侧序列-160位点的DNA片段,长约190 bp.分别用限制性内切酶HphⅠ和AflⅢ将PCR产物消化过夜,行4%琼脂糖凝胶电泳,根据酶切产物的电泳结果判断基因型.结果 浅表膀胱移行细胞癌的CC、CA、AA基因型分别有9、14和10例;浸润膀胱移行细胞癌的CC、CA、AA基因型分别有2、3和12例.浸润性膀胱移行细胞癌A等位基因频率0.79(27/7)高于浅表性膀胱移行细胞癌0.52(34/32),差异有统计学意义(P＜0.05).结论 E-cad基因启动子近侧序列-160位点A等位基因与膀胱移行细胞癌的侵袭能力密切相关.     

E-cadherin immunostaining of bladder transitional cell carcinoma, carcinoma in situ and lymph node metastases with long-term followup

PURPOSE: We analyze the expression of E-cadherin in bladder transitional cell carcinoma, areas of carcinoma in situ and lymph node metastases, and determine the value of E-cadherin immunoreactivity for predicting disease progression and survival of patients with bladder transitional cell carcinoma. MATERIALS AND METHODS: The study group consisted of 77 patients who underwent radical cystectomy. Formalin fixed paraffin sections were processed with a hot, citric acid antigen retrieval method, followed by immunostaining with anti-E-cadherin monoclonal antibody and a standard avidin biotin complex technique. E-cadherin expression was also evaluated in carcinoma in situ sections (18) and in regional lymph node metastases (17). RESULTS: Loss of normal membrane E-cadherin immunoreactivity was found in 59 (77%) patients. Abnormal expression of E-cadherin was associated with muscle invasive disease (p = 0.010) and lymph node metastasis (p = 0.044). Of the 18 carcinoma in situ specimens 15 (83%) and of the 17 metastatic lymph nodes 13 (76%) had abnormal E-cadherin expression. Concordance rates of E-cadherin status in carcinoma in situ areas and metastatic lymph nodes with the primary tumors were 85% and 88%, respectively. At a median followup of 128 months, abnormal E-cadherin expression was significantly associated with disease progression (p = 0.0219) and bladder cancer specific survival (p = 0.037). E-cadherin expression and pathological stage but not grade were independent predictors of disease progression (p = 0.042, 0.047 and 0.158, respectively). CONCLUSIONS: In bladder cancer altered E-cadherin expression is associated with the degree of invasiveness, lymph node metastasis and increased risk of death from bladder cancer. Furthermore, E-cadherin status is an independent predictor of disease progression in patients treated with cystectomy for transitional cell carcinoma of the bladder.     

膀胱移行细胞癌患者血浆p14基因异常甲基化检测的意义

目的检测膀胱移行细胞癌患者血浆p14基因启动子异常甲基化状态,探讨血浆p14基因甲基化改变作为膀胱移行细胞癌分子生物学标志物的可能。方法采用甲基化特异性聚合酶链反应(methylation-specific PCR,MSP)技术,分别检测62例膀胱移行细胞癌患者血浆和相应肿瘤组织DNA的p14基因甲基化状态。结果血浆和肿瘤组织中,p14基因甲基化的阳性率分别为43.5%(27/62)和46.8%(29/62),血浆和肿瘤组织的总体符合率93.1%(27/29),血浆p14基因的甲基化状况与肿瘤组织中是否出现p14基因甲基化具有显著相关性(P<0.01)。血浆和肿瘤组织中,p14基因甲基化与膀胱移行细胞癌的病理分级和临床分期均呈正相关。结论p14基因的甲基化状态改变在膀胱移行细胞癌的发生起重要的作用。血浆p14基因甲基化的检测是膀胱移行细胞癌诊断和判断预后的一个有效的分子生物学指标。     

Cyclooxygenase-2 is highly expressed in carcinoma in situ and T1 transitional cell carcinoma of the bladder

PURPOSE: We describe cyclooxygenase-2 (COX-2) expression patterns in patients with carcinoma in situ and/or stage T1 transitional cell carcinoma. We determined whether expression is associated with clinical outcome in these patients. MATERIALS AND METHODS: Immunostaining for COX-2 was performed on paraffin embedded bladder biopsy specimens from 2 independent groups of patients without muscle invasive carcinoma, including 39 with carcinoma in situ and 34 with stage T1 tumors. Immunoreactivity was scored as the percent of carcinoma in situ cells with cytoplasmic staining for COX-2 in the carcinoma in situ group and as the percent of stage T1 cells expressing COX-2 in the stage T1 transitional cell carcinoma group. We evaluated other molecular alterations, including E-cadherin, p21 and p53, because evidence suggests a biological association of COX-2 with alterations in these molecular markers. RESULTS: In the carcinoma in situ group 5 patients (13%) had no immunoreactivity, while 2 (5%), 5 (13%) and 27 (69%) had 10%, 20% and 30% or greater carcinoma in situ cells positive for COX-2, respectively. In the transitional cell carcinoma group 1 (3%), 4 (12%) and 29 (85%) patients had 10%, 20% and 30% or greater positive cells, respectively. COX-2 expression was not associated with any clinical or pathological parameters, or with molecular markers regardless of the cutoff used. It was also not associated with clinical outcomes in the stage T1 transitional cell carcinoma group. In the carcinoma in situ group COX-2 expression was significantly associated with disease recurrence using cutoffs of 0% and greater than 10% positive cells, and with disease progression using a greater than 20% cutoff. However, it was not associated with bladder cancer related survival. CONCLUSIONS: COX-2 is expressed in a high percent of patients with carcinoma in situ and stage T1 transitional cell carcinoma, supporting the rationale for chemoprevention studies with selective COX-2. We could not substantiate a role for COX-2 immunohistochemistry for the staging and prognosis of carcinoma in situ and/or stage T1 transitional cell carcinoma.     

Treatment of carcinoma in situ with intravesical bacillus Calmette-Guerin without maintenance

PURPOSE: Data concerning the relative efficacy of intravesical bacillus Calmette-Guerin (BCG) on subgroups of carcinoma in situ of the bladder are limited. We report the outcome of primary carcinoma in situ and carcinoma in situ associated with Ta or T1 transitional cell carcinoma of the bladder treated with BCG. MATERIALS AND METHODS: Between 1987 and 1997, 135 patients (median age 70 years) with biopsy proven bladder carcinoma in situ underwent a standard course of 6 BCG instillations. Patients were divided into group 1-23 patients with primary carcinoma in situ, group 2-37 with carcinoma in situ associated with Ta transitional cell carcinoma and group 3-75 with carcinoma in situ associated with T1 transitional cell carcinoma. RESULTS: Median followup was 41 months. For groups 1 to 3, complete response rates at 3 months were 74% (17 of 23 cases), 70% (26 of 37) and 75% (56 of 75), respectively. The overall progression rates at 5 years were 20% (3 of 15 cases), 18% (4 of 22) and 49% (25 of 51). Cancer specific survival rates were 83% (10 of 12 patients), 86% (12 of 14) and 59% (17 of 29), and the numbers of patients alive with the bladder intact were 60% (9 of 15), 58% (11 of 19) and 30% (12 of 40). Patients in group 3 treated with BCG had progression significantly earlier than those in groups 1 and 2 (log-rank test p = 0.013). A complete response to BCG in group 3 patients significantly delayed time to progression (Cox regression p = 0.001) but did not reduce death from transitional cell carcinoma. Indeed, only 38% (8 of 21) of complete responders were alive with the bladder intact at 5 years. CONCLUSIONS: A single course of BCG is remarkably effective for primary carcinoma in situ and carcinoma in situ associated with Ta transitional cell carcinoma but is suboptimal in patients with carcinoma in situ associated with T1 transitional cell carcinoma. Better outcomes in each of the 3 groups may have occurred with maintenance BCG.     

上皮钙黏素1基因启动子甲基化对结肠癌上皮钙黏素和β-连接素表达的影响

目的 探讨上皮钙黏素基因(CDH1)启动子甲基化与结肠癌上皮钙黏素(E-cadherin)及β-连接素(β-catenin)的表达及临床病理特征的关系.方法 采用甲基化特异性PCR技术检测68例结肠腺癌组织、癌旁组织及正常黏膜组织中CDH1基因启动子甲基化的状况.采用免疫组织化学法检测E-cadherin及β-catenin蛋白的表达.结果 癌旁组织及癌组织中CDH1启动子甲基化的阳性表达分别为32.4%(22/68)、57.4%(39/68),正常组织均为阴性表达(P<0.05).E-cadherin在正常组织、癌旁组织及腺癌组织中阳性表达率分别为92.6%、66.2%和44.1%.正常组织中β-catenin均表达于细胞膜上,无胞质和(或)胞核表达,而β-catenin在癌旁组织及癌组织中胞质和(或)胞核表达分别为29.4%和50.0%.CDH1基因启动子甲基化阳性率与E-cadherin表达则呈负相关(r=-0.312,P=0.01),与β-catenin胞质和(或)胞核表达呈正相关(r=0.309,P=0.018).CDH1基因启动子甲基化及E-cadherin、β-catenin的异常表达均与结肠癌分化程度及转移密切相关(P<0.05).结论 CDH1基因启动子甲基化可能是导致结肠癌E-cadherin与β-catenin异常表达及肿瘤侵袭性增强的重要原因.

Abstract：

Objective To investigate the relationship between methylation of the CDH1 gene promoter on the expression of E-cadherin and β-catenin, and to evaluate the correlation with clinicopathological characteristics of the colonic carcinoma. Methods Methylation specific PCR (MSP) was used to detect CDH1 gene promoter methylation in the cancer tissue, adjacent tissues and normal tissues in 68 patients. The expression of E-cadherin and β-catenin was determined by immunohistochemistry staining. Results The positive rate of CDH1 gene promoter methylation was 32.4% in adjacent tissues and 57.4% in cancer tissue, while no detectable methylation was found in all the normal tissues. The difference was statistically significant. The positive rate of E-cadherin was 92.6% in the normal tissues, 66.2% in the adjacent tissues and 44.1% in the cancer tissues. In all normal tissues, β-catenin was expressed only at the cellular membrane but not in the cytosol or nucleus, while the expression of β-catenin was present in the cytosol or nucleus in 29.4% of the adjacent tissues and 50.0% of the cancer tissues. The positive rate of CDH1 gene promoter methylation was negatively correlated with E-cadherin expression (r =-0.312,P =0.01) and positively correlated with β-catenin cytosolic/nucleus expression(r=0.309,P=0.018). The differentiation and metastasis of colonic carcinoma were associated with the aberrant expression of E-cadherin, β-catenin, and methylation of CDH1 promoter (P<0.05). Conclusion CDH1 gene promoter methylation may lead to aberrant expression of E-cadherin and β-catenin in colonic carcinoma, and may play an important role in promoting the invasion of tumor.     

胰腺癌中p16基因甲基化改变及其蛋白表达分析

目的研究p16基因启动子区异常甲基化改变和p16蛋白表达在胰腺癌与癌旁组织中的表达特点,探讨其与胰腺癌发生发展与临床的关系。方法分别以免疫组化法(SP法)及甲基化特异PCR(MSP)检测46例胰腺癌及其癌旁组织中p16基因表达及其甲基化的水平,并结合临床资料进行分析。结果胰腺癌中p16蛋白表达率为41.3%(19/46),而癌旁组织表达率为95.7%(44/46),两者相比差异有统计学意义(P<0.01)。p16蛋白阳性的19例胰腺癌标本,均未检出基因甲基化;p16蛋白缺失的27例标本,有18例检出基因甲基化,甲基化率为39.1%。基因甲基化与p16蛋白缺失明显相关(P<0.05),p16基因表达及p16基因启动子区甲基化的发生率与胰腺癌的大小、患者性别、年龄的差异无统计学意义(P>0.05),但在组织分化程度、有无淋巴结转移、PTNM分期上有统计学意义(P<0.05)。结论p16基因启动子异常甲基化改变可能影响p16蛋白的表达;p16甲基化、蛋白表达与胰腺癌的发生发展密切相关,p16甲基化和蛋白表达是胰腺癌患者诊断及预后的候选标志物之一。     

Genetic analysis of hMLH1 in transitional cell carcinoma of the urinary tract: promoter methylation or mutation

PURPOSE: Loss of DNA mismatch repair due to diminished expression or mutation of hMLH1 is associated with genomic instability followed by cancer. We performed genetic analyses of hMLH1 to determine whether hMLH1 alterations have a role in urothelial tumorigenesis. MATERIALS AND METHODS: We examined genomic DNA from 118 sporadic transitional cell carcinomas, including 83 bladder and 35 renal pelvis or ureter cases, for aberrant promoter methylation and mutation in the hMLH1 gene. Immunohistochemical reactivity to hMLH1 protein and genome instability in these transitional cell carcinomas were also studied. RESULTS: Two of the 118 cases (1.7%) had microsatellite instability and hMLH1 promoter methylation with loss of or reduced hMLH1 protein expression. A single transitional cell carcinoma (0.8%) without microsatellite instability had an hMLH1 missense mutation with a C-to-T transition, resulting in the substitution Arg217 --> Cys. Immunostaining with antihMLH1 antibody was found in this transitional cell carcinoma. CONCLUSIONS: To our knowledge these findings provide the first in vivo evidence for the type and frequency of possible involvement of promoter methylation and mutation of hMLH1 in sporadic urothelial transitional cell carcinoma. They also suggest that hMLH1 alterations may not account for many cases of sporadic transitional cell carcinoma tumorigenesis.     

结肠癌细胞CDH1基因启动子甲基化对E-上皮钙黏素和β-连接素表达的调控作用

目的 观察结肠癌细胞中上皮钙黏素基因( CDH1)启动子甲基化对上皮钙黏素(E-cadherin)和β－连接素(β-catenin)表达的影响.方法 通过甲基化特异性PCR(MSP)、逆转录－聚合酶链反应(RT-PCR)检测DNA甲基化抑制剂5-氮-2’-脱氧胞苷(5-Aza-CdR)干预前后人结肠癌HT-29细胞株CDH1基因启动子甲基化状态及E-cadherin mRNA的改变,并运用免疫荧光标记及激光共聚焦观察E -cadherin和β-catenin在细胞内的表达及分布.结果 (1)HT-29细胞在用药前CDH1基因启动子甲基化扩增阳性,非甲基化扩增阴性,用5-Aza-CdR处理后CDH1基因启动子甲基化扩增阴性,非甲基化扩增阳性;(2)5-Aza-CdR处理前细胞RT-PCR不能扩增出E-cadherin mRNA特异性条带,5-Aza-CdR处理后则可检测到E-cadherin mRNA转录,且mRNA水平与药物的浓度呈正相关,平均灰度比值1 μmol/L时为0.491±0.011,2μmol/L时为0.568±0.013(P＜0.05;(3)5-Aza-CdR 处理前细胞未见E-cadherin表达,β-catenin主要表达于细胞质及细胞核中,5-Aza-CdR处理后在细胞膜可见E-cadherin及β-catenin表达.且随着5-Aza-CdR诱导E-cadherin的表达,β-catenin在细胞膜的分布增加,而在细胞质及细胞核的分布明显减少.免疫荧光双重染色显示β-catenin胞膜分布与E-cadherin一致.结论 CDH1基因启动子甲基化可能是导致结肠癌细胞E-cadherin表达缺失及β-catenin异位分布的重要因素.     

Assessing the use of p16(INK4a) promoter gene methylation in serum for detection of bladder cancer

OBJECTIVE: This study was undertaken to investigate whether hypermethylation in p16(INK4a) gene promoter could serve as plasma biomarker of bladder cancer. METHODS AND PATIENTS: We examined the p16(INK4a) status using methylation-specific PCR in 86 cancer patients and 49 controls (31 healthy people and 18 patients with benign urological diseases). RESULTS: The p16(INK4a) methylation was found in 22% of the serum samples and in 26% of the bladder cancer biopsies; one of them with carcinoma in situ. The presence of hypermethylated p16(INK4a) in serum seems to be a product from tumour cells because a strong statistical association was found between both matched DNA signals (p<0.0001). Using the control group, the presence of methylated p16(INK4a) in the serum of individuals with suspicion of bladder cancer was found to be associated with the tumour presence (p=0.0009). Aberrant p16(INK4a) methylation was also observed in one non-cancer patient, which is undergoing further assessment. CONCLUSIONS: According with our results, methylation of p16(INK4a) promoter may be involved in the bladder cancer genesis and the presence of p16(INK4a) methylated in serum of these patients could be useful in the cancer diagnosis with values of sensitivity, specificity and positive predictive value of 0.226, 0.950 and 0.98, respectively. These figures support the use of methylated p16(INK4a) as a new class of tumour marker in bladder cancer.     

DNA-Methylierung in der Urindiagnostik und als Prognosemarker beim Urothelkarzinom der Harnblase

INTRODUCTION AND OBJECTIVES: Detection of promoter hypermethylation has been proposed as a promising tool for cancer diagnosis and as a prognostic marker in various cancers. We studied the versatility of DNA methylation for noninvasive diagnosis and as a prognostic marker for non-muscle-invasive bladder carcinoma. METHODS: Tumor specimens were microdissected and DNA was extracted from 105 paraffin-embedded paraffin specimens from patients undergoing transurethral resection for non-muscle-invasive bladder carcinoma. Urine specimens were collected from patients undergoing cystectomy for bladder cancer and from healthy volunteers. Methylation status was assessed with the real-time quantitative methylation-sensitive PCR (MethyLight). We checked a panel of 20 cancer-associated genes (p14ARF, p16 CDKN2A, STAT-1, SOCS-1, DR-3, DR-6, PIG-7, BCL-2, H-TERT, BAX, EDNRB, DAPK, RASSF-1A, FADD, TMS-1, E-CADHERIN, ICAM-1, TIMP-3, MLH-1, COX-2) for DNA methylation. RESULTS: Follow-up data were available in 95 of 105 patients (91.4%). A tumor recurrence was observed in 26 patients (27.3%). We could identify six genes (SOCS-1, STAT-1, BCL-2, DAPK, TIMP-3, E-cadherin), where methylation was associated with tumor recurrence. In Kaplan-Meier analysis, TIMP-3 showed a significant association with recurrence-free survival. Methylation of TIMP-3 predicted prolonged disease-free interval. Regarding urinalysis we could identify a pattern of methylation markers including DAPK, BCL-2, and H-TERT that yielded a sensitivity of 81.1% with a specificity of 100% in a cancer-free control population CONCLUSIONS: We present data on the clinical usefulness of methylation analysis in bladder carcinoma. Our data confirm that methylation analysis is a promising tool for bladder cancer diagnosis and prognosis.     

膀胱癌WIF-1启动子甲基化状态及其与膀胱癌临床病理关系的研究

目的:研究Wnt抑制因子1(WIF-1)启动子甲基化状态对WIF-1蛋白表达的影响及其与膀胱癌的临床病理关系。方法:采用甲基化特异性PCR方法和免疫组织化学方法检测57例膀胱癌WIF-1启动子甲基化状态和WIF-1蛋白表达情况。以正常膀胱黏膜及腺性膀胱炎组织为对照。结果:膀胱癌、腺性膀胱炎和正常膀胱组织WIF-1启动子甲基化率分别为57.9%,15.0%和0,差异有统计学意义(P<0.01)。WIF-1启动子甲基化阳性率随肿瘤分级、分期的增加逐渐升高(G1、G2、G3级分别为20.0%、56.3%和86.7%;浅表性和浸润性肿瘤分别为43.8%和76%,P<0.01)。膀胱癌组织WIF-1基因启动子甲基化时WIF-1蛋白表达率明显低于未甲基化组(P<0.001,Kappa值为0.783)。WIF-1甲基化与未甲基化组膀胱癌患者之间的5年总生存率分别为60.6%和91.7%(P<0.05)。结论:膀胱癌WIF-1蛋白表达缺失或减少与WIF-1启动子甲基化密切相关。WIF-1启动子甲基化可能是膀胱肿瘤发生的早期事件,而且与肿瘤的进展有关,可作为膀胱癌患者预后判断分子标志物。     

Clinical study of transitional cell carcinoma of the prostate associated with bladder transitional cell carcinoma

BACKGROUND: Transitional cell carcinoma of the prostate in patients with bladder cancer appears to influence the prognosis and affects the decision about therapeutic modality. Therefore, it is important to characterize transitional cell carcinoma associated with bladder cancer. METHODS: From April 1980 to December 1998, 81 male patients underwent total cystoprostatectomies for transitional cell carcinoma of the bladder. The 81 cystoprostatectomy specimens were examined to clarify the characteristics of prostatic involvement by transitional cell carcinoma. The extent, origin, mode of spread and risk factor of prostatic involvement as well as the prognosis were investigated. In 13 of 15 patients with prostatic involvement the prostate was examined by sequential step sections. RESULTS: Prostatic involvement was observed in 15 of 81 patients (18.5%). Prostatic urethral involvement, invasion to prostatic duct/acinus, prostatic stromal invasion and extraprostatic extension and/or seminal vesicle involvement were recognized in 12 (80%), 14 (93.3%), six (40%), and five (33.3%) of the 15 patients, respectively. Twelve of the 15 patients (80%) with prostatic involvement had papillary or non-papillary tumors (i.e. carcinoma in situ) both in the prostatic urethra and prostatic duct. In 10 of these 12 patients (88.3%), there was contiguity between prostatic urethral and ductal tumors. Seven of the 23 patients (30.4%) with carcinoma in situ of the bladder showed prostatic involvement, which increased to 50% in the presence of carcinoma in situ of the trigone or bladder neck. CONCLUSIONS: Eighty per cent of the patients with prostatic involvement showed papillary or non-papillary tumors both in the prostatic urethra and prostatic duct. There was a high level of contiguity between both tumors. Patients with carcinoma in situ of the trigone or bladder neck revealed significantly higher incidence of prostatic involvement.     

膀胱癌和肾癌组织中RASSF1A基因的甲基化改变

目的研究RASSF1A基因启动子的甲基化状态及在膀胱癌和肾癌发生中的作用。方法采用甲基化特异性PCR(MSP)技术检测45例手术切除的膀胱癌组织和相应癌旁正常组织标本、9例电切膀胱癌组织、3例非肿瘤患者正常膀胱组织、12例肾癌组织和相应癌旁正常组织标本中RASSF1A基因的甲基化情况。结果膀胱癌组织中RASSF1A基因异常甲基化55.6%(30/54),其中手术切除组57.8%(26/45),电切癌组织异常甲基化4例,癌旁正常组织基因异常甲基化1例;肾癌组织中基因异常甲基化66.7%(8/12),相应癌旁正常组织中未发现基因甲基化。3例正常膀胱组织标本中未发现基因异常甲基化。膀胱癌组织中RASSF1A基因甲基化率有随组织分期升高的趋势,但与临床病理参数间无明显相关性。结论膀胱癌和肾癌组织中RASSF1A基因启动子高度甲基化,表明该基因甲基化可能与2种肿瘤的发生相关。     

E-钙黏附素基因甲基化与结直肠癌临床病理特征的关系

目的探讨E-钙黏附素（E-cadherin）基因甲基化与结直肠癌临床病理特征的关系。方法采用甲基化特异性巢式PCR技术（nMSP法）研究100例结直肠癌组织及100例癌旁组织E-eadherin基因甲基化与临床病理特征的关系。结果100例结直肠癌组织中有33例呈E-cad基因甲基化阳性（阳性率33.0％），相应的癌旁组织无甲基化。Dukes分期中C、D期组织E-cad基因甲基化阳性率（72.7％）明显高于A、B期（27.3％）（P〈0.05）；伴肝转移的结直肠癌组织甲基化阳性率（81．8％）明显高于无肝转移者（18．2％）（P〈0．01）；在肿瘤细胞分化程度、大体类型、年龄、性别和肿瘤部位等其他病理特征，E-cad基因甲基化阳性组与阴性组差异无统计学意义（P〉0．05）。结论结直肠癌组织E-cad基因甲基化与淋巴结转移、肝转移和Dukes分期明显相关，E-cad基因甲基化可能是结直肠癌侵袭性增强的原因之一。     

错配修复基因hMLH1在膀胱移行细胞癌中的表达及其意义

目的 观察错配修复基因hMLH1在膀胱移行细胞癌中的表达,探讨hMLH1与膀胱移行细胞癌的关系.方法 通过免疫组织化学方法 测定hMLH1在80例膀胱移行细胞癌中及20例正常膀胱组织中的表达.结果 hMLH1在膀胱移行细胞癌中的低表达率(32.5%)明显高于在正常膀胱组织中的低表达率(0%),差异有统计学意义(P＜0.05),且hMLH1在膀胱移行细胞癌中的低表达与肿瘤的分期分级有关(P＜0.05).结论 hMLH1的低表达与膀胱移行细胞癌的发生有关,与肿瘤的高分期和高分级有关,hMLH1的低表达在浸润性及分化差的膀胱移行细胞癌多见.     

膀胱移行细胞癌微卫星不稳定性表达及机理探讨

目的 探讨微卫星不稳定性在膀胱移行细胞癌的表达及其作用机制。方法 用PCR方法分析35例膀胱移行细胞癌尿沉渣标本中微卫星不稳定性表达;用RT-PCR方法监测5种人类错配修复基因在膀胱癌细胞系mRNA转录水平的表达;用PCR方法检测膀胱癌细胞系BIU-87中错配修复基因hMLH1的启动子区域出现异常甲基化。结果 35例膀胱癌患者尿沉渣中,有31例（88.6%)可检出微卫星不稳定性表现;5种人的错配修复基因在BIU-87膀胱癌细胞系中有hMLH1和hMSH2表达缺失,而在正常近曲小管细胞系中都有表达;BIU-87细胞错配修复基因hMLH1的启动子区域出现异常甲基化,应用去甲基化剂处理后可检测到hMLH1的启动子区域的表达,再次去除去甲基化剂后叠不能检测hMLH1的启动子区域。结论 微卫星不稳定性与错配修复基因表达有关。甲基化对膀胱癌细胞系BIU-87错配修复基因hMLH1的表达具有调控作用。