K—ras基因在胰腺癌诊断治疗中的意义

Ｋ－ｒａｓ基因在胰腺癌中突变率很高（７５－１００％），且仅在胰导管源性肿瘤中存在，在与内分泌源性肿瘤等无关，有研究 胰导管的某些粘液性增生病灶中即存在Ｋ－ｒａｓ基因的突变。这些突变绝大部分集中在Ｋ－ｒａｓ基因的１２密码子，该痊点碱基穴变的类型则呈现地域性差异，可能与不同地区不同致病因子有关。检测活检标本或胰液中Ｋ－ｒａｓ的突变，有望作为胰腺癌早期诊断的方法，且这一广泛存在的突变可作为胰腺癌基因的治     

用PCR和直接测序方法分析胰腺的c-Ki-ras基因点突变

用ＰＣＲ和直接测序方法分析胰腺的ｃ－Ｋｉ－ｒａｓ基因点突变徐永泉，刘述信，夏玉亭人类肿瘤中最常见的与转化活性有关的基因ｒａｓ家族癌基因（Ｎ－ｒａｓ，Ｋｉ－ｒａｓ，Ｈａ－ｒａｓ）。ｒａｓ基因的激活在肿瘤发生中起重要作用。ｒａｓ基因激活的主要方式是点突变...     

肺癌K－ras基因突变的检测及临床应用

为探讨基因检测在肺癌中的应用价值，应用ＰＣＲ－ＲＦＬＰ法检测１０２例肺癌患者手术标本中Ｋ－ｒａｓ基因第１２密码子突变的状况。并将肺腺癌按临床病理特征分组进行对比分析。结果显示，肺癌中总突变率为２４％，腺癌中为４９％，鳞癌为１５％，而小细胞癌中无一例突变。吸烟是促发Ｋ－ｒａｓ基因突变的重要因素（Ｐ＜０．０５），肺腺癌突变组淋巴结转移早、部位远，其一年复发率达８５％，明显高于未突变组（Ｐ＜０．０１）。Ｋ－ｒａｓ基因突变的检测具有重要的临床意义和应用价值。     

血浆k-ras基因突变及与胰腺癌临床生物学特性关系

胰腺癌是最常见的恶性肿瘤。近年来 ,其发病率呈增高趋势。许多研究表明 ,胰腺癌ｋ ｒａｓ基因突变的发生率高达90 %以上 ,且主要位于第 12密码子[1,2 ] 。而慢性胰腺炎等胰腺良性疾病则罕有发生。因此 ,检测ｋ ｒａｓ基因 12密码子突变为诊断胰腺癌提供了可靠的分子生物学基础。我们分别应用高度敏感的突变等位基因特异性扩增 (ｍｕｔａｎｔａｌｌｅｌｅｓｐｅ ｃｉｆｉｃａｍｐｌｉｆｉｃａｔｉｏｎ ,ＭＡＳＡ)和突变富集聚合酶链反应 限制性片段长度多态性 (ＭＥ ＰＣＲ ＲＦＬＰ)技术 ,检测胰腺癌患者外周血浆ｋ ｒａｓ基因突变 ,以评…     

肺癌K—ras基因突变的检测及临床应用

为探讨基因检测在肺癌中的应用价值，应用ＰＣＲ－ＲＦＬＰ法检测１０２例肺癌患者手术标本中Ｋ－ｒａｓ基因第１２密码子突变的状况。并将肺腺癌按临床病理特征分组进行对比分析。结果显示，肺癌中总突变率为２４％，腺癌中为４９％，鳞癌为１５％，而小细胞癌中无一例突变。吸烟是促发Ｋ－ｒａｓ基因突变的重要因素（Ｐ〈０．０５），肺腺癌突变组淋巴结转移早、部位远，其一年复发率达８５％，明显高于未突变组（Ｐ〈０．０１）。     

血清HBsAg阳性患者肝癌及癌旁组织中P^53和K—ras基因突变及其相…

应用ＰＣＲ－ＳＳＣＰ方法对２４例血清ＨＢｓＡｇ患者肝癌及癌旁组织中Ｐ＾５３和Ｋ－ｒａｓ基因突变进行了检测。肝癌组织中Ｐ＾５３基因突变率为３３％，Ｋ－ｒａｓ基因突变率为２５％，癌旁正常组织中无Ｐ＾５３和Ｋ－ｒａｓ基因突变，癌旁硬化组织中Ｋ－ｒａｓ突变为１５％，无Ｐ＾５３基因突变。     

胃癌组织ras基因群点突变及其一患者预后的关系(英文)

目的研究ｒａｓ基因点突变与胃癌患者预后的关系．方法应用多聚酶链延伸反应—限制性片段长度多态性分析法（ＰＣＲ－ＲＦＬＰ）对８８例福尔马林固定，石蜡包埋胃癌组织ＣＨａｒａｓ第１２位、６１位，Ｋｒａｓ第１２位、１３位和Ｎｒａｓ第１２位密码子的点突变进行检测．结果ｒａｓ基因群总突率为１８２％（１６／８８），点突变的与肿瘤浆膜浸润、淋巴结转移、临床病理分期及术后的生存期密切相关．结论检测胃癌组织ｒａｓ基因群点突变有助于判断胃癌患者的预后．     

胰腺癌患者手术标本及胰液脱落细胞端粒酶活性的检测

目的 研究胰腺良，恶性患者手术标本，经ERCP所获胰液脱落细胞的端粒酶活性的表达，探索胰腺癌诊断的新方法。方法 采用TRAP-ELISA的方法检测胰腺癌细胞株，胰腺良恶性疾病组织物，胰液细胞的端粒酶活性。结果 6株胰腺癌细胞株均检测到了端粒酶活性，胰腺癌手术标本端粒酶的阳性率为63%（5/8），而4例正常胰腺组织和2例胰腺良性疾病患者的胰腺标本未检测到端粒酶活性，胰腺癌患者的胰液细胞中，有58%（11/19）检测到有端粒酶活性的表达，而胰腺良性疾病也有高达62.5%(5/8)的阳笥率，两者无差别。结论 胰腺癌组织标本中有较高的端粒酶活性表达；胰液脱落细胞检测端粒酶活性无助于鉴别胰腺良恶性疾病。     

胰腺癌的基因诊断研究现状

本综述了目前可用于胰腺癌临床诊断的相关基因,认为Ｋ－ｒａｓ基因及端粒酶基因最有诊断价值。Ｋ－ｒａｓ基因在胰腺癌中的突变率为７５－１００％,检测端粒栈阔与诊断胰腺癌有１００％的敏感性及特异性。尽管Ｐ５３基因在胰腺癌中有一定的突变率,但单独用于临床诊断的意义不大。ＤＰＣ４基因是新近发现的一种抑癌基因,在胰腺癌中的炫约５０％,有望进一步用于临床。临床上获取用于检测的标本,主要通过经皮细针穿刺活检、ＥＲ     

ras癌基因第12密码子点突变和胃癌患者预后关系的研究

对福尔马林固定，石蜡包埋的胃癌组织使用移聚酶链式反应－限制性片段长度多态性（简称ＰＣＲ－ＲＦＬＰ）技术同时进行ｃ－Ｈａ－ｒａｓ基因第１２位和６１位，Ｎ－ｒａｓ基因第１２位，ｋ－ｒａｓ第１２位和１３位密码子点突变的研究，发现３３．３％（１４／４２），的胃癌有ｃ－Ｈａ－ｒａｓ基因第１２位密码子的点突变；４．８％（２／４２）的病例有ｋ－ｒａｓ基因第１２位密码子的点突变，点突变的发生与患者的预后，淋巴结转     

胰液K-ras基因突变和血清CA19-9联合检测判断胰腺癌复发

目的研究胰液中K-ras12密码子点突变和血清CA19-9联合检测结果与胰腺癌病程的关系。方法测定32例临床及手术证实的胰腺癌患者血清CA19-9水平,同时采用内镜ERCP从胰管收集胰液标本,应用聚合酶链反应限制性片断长度多态性分析(PCR-RFLP)检测胰液K-ras基因12密码子点突变,分析K-ras12密码子点突变及血清CA19-9水平联合检测结果与胰腺癌临床特征和术后复发的关系。结果 (1)胰液中K-ras12密码子点突变率为56．3％,与肿瘤大小密切相关(P<0．05)。K-ras12密码子点突变阳性、阴性表达病例3年复发率分别为66．7％和33．3％。(2)高血清CA19-9水平且K-ras12密码子点突变阳性组3年复发率为69．2％,而低血清CA19-9水平且K-ras12密码子点突变阴性组3年复发率为20．0％,两组差异显著(P<0．05)。结论联合胰液中K-ras12密码子点突变和血清CA19-9检测可作为判断胰腺癌术后复发的有效指标,多因素分析对胰腺癌术后复发的判断更有价值。     

顺序特异性引物法快速检测胰腺癌K—ras基因点突变

目的：研究简捷、特异、敏感的检测胰腺癌K－ras基因点突变的方法及其在胰腺疾病中定性诊断的价值。方法：采用针对K－ras基因点突变方式（CGT、GAT、GTT）设计的顺序特异性引物（SSP），先后对胰腺癌石蜡包埋组织、冰冻新鲜组织、细针穿刺组织及胰液进行多聚酶链反应（PCR），扩增产物借助常规电泳和染色检测有无K－ras基因突变及突变方式。结果：胰腺癌石蜡包埋组织、冰冻新鲜组织、细针穿刺组织及胰液中K－ras基因点突变率分别为74．2％、95．1％、91．4％及94．1％，而所有被检测的慢性胰腺炎、胰岛素瘤、壶腹癌、胆管癌、十二指肠乳头癌及外伤胰腺的组织标本和胰液标本均无K－ras基因突变发生。结论：该检测法简便、快速、特异、敏感，具有临床实用性，可以作为鉴别胰腺肿块良恶性和诊断胰腺癌的一种方法。     

胰液K-ras密码子点突变联合血清CA 199水平与胰腺癌复发关系的研究

目的探讨胰液中K-ras 12密码子点突变联合血清CA199检测与胰腺癌病程的关系。方法测定32例临床及手术证实的胰腺癌患者血清CA199水平,并采用内镜ERCP从胰管收集的胰液标本,聚合酶链反应-限制性片段长度多态性分析(PCR-RFLP)检测胰液K-ras 12基因12密码子点突变,分析胰液中K-ras 12密码子点突变及血清CA199联合检测与胰腺癌术后复发的关系。结果(1)胰液中K-ras 12密码子点突变率为56.3%,与肿瘤大小密切相关(P<0.05)。K-ras 12密码子点突变阳性、阴性表达病例3年复发率分别为66.7%和33.3%。(2)高血清CA199水平且K-ras 12密码子点突变阳性病例组3年复发率为69.2%,而低血清CA199且ras阳性病例组3年复发率为20.0%,差异显著(P<0.05)。结论联合胰液中K-ras 12密码子点突变及血清CA199检测可作为判断胰腺癌术后复发的有效指标,多因素分析对胰腺癌术后复发的判断更有价值。     

Telomerase activity in pure pancreatic juice for the diagnosis of pancreatic cancer may be complementary to K-ras mutation

BACKGROUND: The usefulness of K-ras mutation in pancreatic juice for the diagnosis of pancreatic cancer is questionable. Telomerase is positive in pancreatic cancer but rarely in benign pancreatic diseases. We conducted this study to determine the usefulness of K-ras mutation and telomerase activity in pancreatic juice for the diagnosis of pancreatic cancer. METHODS: Pancreatic juice collected during endoscopic retrograde cholangiopancreatography was examined in 31 patients: 12 with pancreatic cancer, 11 with chronic pancreatitis, and 8 control patients. The K-ras gene was detected by using the restriction fragment length polymorphism method. Telomerase activity was detected by using the telomeric repeat amplification protocol. RESULTS: K-ras mutation was positive in 75% (9 of 12) of pancreatic cancers and in 27% (3 of 11) of cases of chronic pancreatitis but in none of the control patients. Telomerase activity was detected in 92% (11 of 12) of pancreatic cancers and in 18% (2 of 11) of cases of chronic pancreatitis. The diagnostic value in pancreatic cancer was comparable between K-ras mutation and telomerase when evaluated separately. However, by combining these 2 methods, the specificity rose to 100%. CONCLUSIONS: For the diagnosis of pancreatic cancer, telomerase activity in pancreatic juice may possibly be complementary to K-ras mutation because it may decrease the rate of false-positive diagnosis.     

Telomerase activity in pure pancreatic juice for the diagnosis of pancreatic cancer may be complementary to K-ras mutation

Background: The usefulness of K-ras mutation in pancreatic juice for the diagnosis of pancreatic cancer is questionable. Telomerase is positive in pancreatic cancer but rarely in benign pancreatic diseases. We conducted this study to determine the usefulness of K-ras mutation and telomerase activity in pancreatic juice for the diagnosis of pancreatic cancer. Methods: Pancreatic juice collected during endoscopic retrograde cholangiopancreatography was examined in 31 patients: 12 with pancreatic cancer, 11 with chronic pancreatitis, and 8 control patients. The K-ras gene was detected by using the restriction fragment length polymorphism method. Telomerase activity was detected by using the telomeric repeat amplification protocol. Results: K-ras mutation was positive in 75% (9 of 12) of pancreatic cancers and in 27% (3 of 11) of cases of chronic pancreatitis but in none of the control patients. Telomerase activity was detected in 92% (11 of 12) of pancreatic cancers and in 18% (2 of 11) of cases of chronic pancreatitis. The diagnostic value in pancreatic cancer was comparable between K-ras mutation and telomerase when evaluated separately. However, by combining these 2 methods, the specificity rose to 100%. Conclusions: For the diagnosis of pancreatic cancer, telomerase activity in pancreatic juice may possibly be complementary to K-ras mutation because it may decrease the rate of false-positive diagnosis. (Gastrointest Endosc 2000;51:708-13.)     

Does detection of K-ras mutations in pancreatic juice influence clinical decision making?

The majority of patients with pancreatic cancer harbour mutations in the K-ras gene. This oncogene may be detected in material obtained at endoscopic retrograde cholangiopancreatography (ERCP), such as bile and pancreatic juice. Since a formal tissue diagnosis may be difficult to establish in pancreatic cancer, detection of K-ras in these materials is an attractive approach to diagnosis. A variety of molecular techniques has been used to detect K-ras, and frequency of the mutation may vary between different populations. In this issue of the European Journal of Gastroenterology and Hepatology, Boadas et al. collected pancreatic juice following secretin stimulation at the time of ERCP, and detected K-ras in 44% of patients with pancreatic cancer. They found the mutation in 16% of patients with chronic pancreatitis. Presence of the mutation, therefore, is not specific enough to recommend its use in the clinical diagnosis of pancreatic cancer. Chronic pancreatitis patients with the mutation may be at higher risk of developing pancreatic cancer than those patients without the mutation, but there is no clear consensus on management and follow-up of these patients.     

PCR—MASA检测胰腺癌外周血K—ras基因点突变的研究

目的 了解胰腺癌外周血中K—ras基因点突变检测的临床价值。方法 采用PCR—MASA法检测胰腺癌患外周血中K—ras基因点突变。结果胰腺癌外周血标本中K—ras基因点突变率为38．1％(8／21)，而所有被检测的急、慢性胰腺炎、胰岛素瘤、壶腹癌、十二指肠乳头癌、胆管癌及胆石症患外周血标本均无K—ras基因突变。结论 (1)PCR—MASA方法简捷、特异、敏感，扩增产物只需常规电泳、染色即可观察结果，无需酶切、杂交、放射性和非放射性显影；(2)对外周血标本检测K—ras基因第12位密码子有无突变，具有临床实用性，有助于判断胰腺病变良恶性及胰腺癌的早期诊断。     

High proportion of mutant K-ras gene in pancreatic juice of patients with pancreatic cystic lesions

BACKGROUND/AIMS: It was recently reported that the quantitative analysis of mutant K-ras gene in pancreatic juice could be useful for the diagnosis of pancreatic cancer. This methodology was applied to patients with pancreatic cystic lesions. METHODS: DNA was extracted from pancreatic juice collected at the time of endoscopy with injection of secretin. The ratio of the K-ras mutant allele to the wild-type allele was measured by two methods to detect and semiquantify mutant K-ras gene: polymerase chain reaction/preferential homoduplex formation assay and enriched polymerase chain reaction/enzyme linked mini-sequence assay. RESULTS: A high frequency of K-ras mutation was detected (more than 2% of all K-ras genes) in six of 14 patients (43%) with pancreatic cysts. This frequency was similar to those detected in patients with pancreatic adenocarcinoma and in intraductal papillary neoplasms of the pancreas. In contrast, the frequency of mutation was low (less than 2%) in patients without either pancreatic cysts or pancreatic neoplasms. CONCLUSIONS: K-ras gene mutation may be derived from duct cells in the pancreas with a high potential for tumorigenesis. Therefore careful follow up of patients with a pancreatic cyst is recommended if they are found to have a high level of the mutant gene in the pancreatic juice.     

Clinical usefulness of K-ras gene mutation detection and cytology in pancreatic juice in the diagnosis and screening of pancreatic cancer.

BACKGROUND: The significance of K-ras codon 12 mutation in pancreatic juice is still unclear. Although considerable controversy surrounds this question, the diagnostic utility of K-ras in patients with clinical suspicion of pancreatic cancer (PC) and in PC-risk patients remains unknown. OBJECTIVE: To study prospectively the utility of the K-ras gene mutation and cytology in the diagnosis and screening of PC, and to assess its contribution to clinical decision making. METHODS: Pancreatic juice samples obtained from 90 patients were evaluated prospectively. Group I (n = 40) comprised patients with clinical suspicion of PC; group II (n = 50) comprised 49 patients with chronic pancreatitis and one patient proceeding from a PC family screening. The K-ras mutation was detected by means of artificial restriction fragment length polymorphisms (RFLP) in DNA after polymerase chain reaction (PCR) amplification. RESULTS: In group I, of those patients with a definitive diagnosis of PC, malignant cells were found in 27% and K-ras mutation in 44%. In five cases, molecular analysis contributed to diagnosis (4/11 with negative cytology and 1/2 with insufficient cytological material). K-ras mutation revealed an early tumour in one patient, and was the only sample available for diagnosis in another. In group II, the K-ras gene mutation was detected in 8/49 patients (16%) with chronic pancreatitis, one of whom developed PC (2%). CONCLUSIONS: K-ras mutation analysis of pancreatic juice may complement cytological evaluation in the diagnosis of PC, in spite of its limited contribution to clinical decision making. The presence of K-ras mutation in chronic pancreatitis classifies a subgroup of PC-risk patients who should be evaluated carefully by long-term follow-up.