Analysis of Tumor-Related Genes In Pancreatic Juice Aiming to be Useful for Early Diagnosis of Pancreatic Cancer

我们分析了经ERCP吸出的胰液（PJ）沉淀物（Sed）、上清液（sup）和经PTC或ERBD获得的胆汁DNA提取物中p53的突变。在胰腺癌患者PJ的Sup和Sed中，p53突变的发生率分别为43%（9/21）和29%（6/21），在Sup和Sed联合检测中，p53突变的发生率为52%（11/21）。此外，在47%（7/15）的细胞学诊断为阴性的PCa病例中检测到p53突变。在25例慢性胰腺炎（CP）患者中，无突变p53。胆管癌患者胆汁中p53突变阳性率Sup为50%（15/30），Sed为33%（10/30）。另一方面，没有胆石症患者携带突变型p53。这些结果表明，p53突变在Sup中的发生率高于Sed，且Sup中p53突变的特异性高于Sed。 ...更多信息 p53基因突变对肿瘤的特异性很高。PJ中Mesothlin mRNA的表达在PCa、IPMN和CP中分别为52%（11/21）、45%（5/11）和14%（3/22）。PCa与CP间皮素mRNA表达差异有统计学意义。我们开发了一种高灵敏度的h-TERTmRNA定量分析方法，采用实时RT-PCR，并测量了血清和PJ中h-TERTmRNA的量。h-TERTmRNA水平在几乎所有PCa病例中均升高，但在相当多的良性病变病例中也升高，表明h-TERTmRNA对癌症的特异性较低。采用甲基化特异性PCR方法，对PJ组织中ppENK、SARP 2和NPTX 2 3个CpG岛的甲基化状态进行了分析。PJ中ppENK异常甲基化在28例PCa患者中的14例（50%）、15例IPMN患者中的4例（27%）和20例CP患者中的1例（15%）中检测到; NPTX 2异常甲基化在35例PCa患者中的24例（77%）、16例IPMN患者中的10例（63%）和13例CP患者中的6例（43%）中检测到。ppENK或NPTX 2异常甲基化的发生率在PCa中显著高于CP。此外，我们在35例PCa患者中的24例（74%），16例IPMN患者中的15例（94%）和19例CP患者中的2例（11%）中发现了PJ中SARP 2的异常甲基化。SARP 2异常甲基化的发生率在PCa或IPMN中显著高于CP。尽管前列腺癌PJ中肿瘤相关基因异常甲基化的发生率非常高，但其对癌症的特异性并不足够。良性和恶性组的IPMN之间没有显着差异，这表明这些基因的异常甲基化是PCa发展的早期事件，PJ中异常甲基化的定量检测可能对PCa具有潜在的诊断意义。少

We analyzed mutations of p53 in DNA extract not only from the sediment(Sed) but also from the supernatant(sup) of aspirated pancreatic juice(PJ) by ERCP and bile obtained by PTC or ERBD. The incidence of p53 mutations was 43%(9 of 21) and 29%(6 of 21) in the Sup and the Sed of PJ from patients with pancreatic cancer(PCa), respectively, and nurse to 52%(11 of 21) in the combination assay with Sup and Sed. Moreover, p53 mutations were detected in 47%(7 of 15) of PCa cases in which the cyto logic diagnosis was negative. Among 25 patients with chronic pancreatitis(CP), none harbored mutant p53. In bile abtained from patients with biliary tract cancer, the positive rate of p53 mutations was 50%(15 of 30) in the Sup and 33%(10 of 30) in the Sed. On the other hand, there were no pantients with cholelithiasis harboring mutant p53. These results could indicate that the incidence of p53 mutation was higher in the Sup than in the Sed, and the specificity of p53 mutation was higher in the Sup than … More in the Sed, and the specificity of p53 mutation for cancer was very high. Mesothlin mRNA expression in the PJ was discovered in 11(52%) of 21 patients with PCa,5(45%) of 11 with intraductal papillary mucinous neoplasm(IPMN) and 3(14%) of 22 with CP. There was significant difference between PCa and CP for mesothelin mRNA. We developed an highly sensitive quantitative analysis for h-TERT mRNA using real-time RT-PCR and measured the amount of h-TERT mRNA in serum and PJ. The levels of h-TERT mRNA were elevated in almost all cases with PCa but also in considerable cases with benign lesions, suggesting low specificity of h-TERT mRNA for cancer. h-TERT mRNA in body fluids from benign lesions originates from lymphocyte.Using methylation-specific PCR, we nextly analyzed the methylation status of 3 CpG islands of ppENK, SARP2 and NPTX2 in PJ samples. Aberrant methylation of ppENK in the PJ was detected in 14(50%) of 28 patients with PCa, 4(27%) of 15 with IPMN and 1(15%) of 20 with CP, and that of NPTX2 was detected in 24(77%) of 35 patients with PCa, 10(63%) of 16 with IPMN and 6(43%) of 13 with CP. The incidence of aberrant methylation of ppENK or NPTX2 was significantly higher in PCa than in CP. Furthermore, we found aberrant methylation of SARP2 in PJ in 24(74%) of 35 patients with PCa, 15(94%) of 16 with IPMN and 2(11%) of 19 with CP. The incidence of aberrant methylation of SARP2 was significantly higher in PCa or IPMN than in CP. Although the prevalence of aberrant methylation of the tumor-related genes in PJ from PCa was strikingly high, its specificity for cancer was not sufficient. There was no significant difference between benign and malignant groups of IPMN, suggesting that aberrant menthylation of these genes is a early event in PCa development, and quantitative detection of aberrant methylation in PJ may have potential diagnostic implication for PCa. Less