多梳基因Bmi-1与胃癌关系研究进展

多梳基因（PcG）在胚胎发育、细胞周期调节、造血干细胞更新、肿瘤发生中起重要作用。转录抑制因子Bmi-1是PcG家族成员之一,与多种人类恶性肿瘤的发生、发展有关。最新研究发现Bmi-1高表达与胃癌的发生、发展、浸润、转移、预后等密切相关。本文就Bmi-1的分子结构、作用机制及其与胃癌关系的研究进展作一综述。     

Clinical and genetic characteristics of Chinese hereditary nonpolyposis colorectal cancer families

AIM: To analyze the clinical characteristics of Chinese hereditary nonpolyposis colorectal cancer (HNPCC) families and to screen the germline mutations of human mismatch repair genes hMLH1 and hMSH2 in the probands.METHODS: Thirty-one independent Chinese HNPCC families were collected in Zhejiang Province. All of them met Chinese HNPCC criteria. Clinical data about patient gender, site of colorectal cancer, age of onset, history of multiple colorectal cancer, associated extracolonic cancer were recorded. PCR and denaturing high performance liquid chromatography (DHPLC) were employed to screen the mutations. Sequencing analysis was used to find out the exact mutation site and characteristics of the samples showing abnormal DHPLC profiles.RESULTS: One hundred and thirty-six malignant neoplasms were found in 107 patients including 14 multiple cancers. One hundred and six of the 136 neoplasms (77.9%) were diagnosed as colorectal cancer, with an average age of onset at 48.57 ± 29.00 years. Gastric cancer was the most common extracolonic cancer (10.3%) in these families. Twenty-three different sequence variations in hMLH1 and hMSH2 genes were detected in these 17 families. Fifteen sequence variations were located in the exons, including 5 SNPs, 3 silent mutations, 3 missense mutations, 2 nonsense mutations and 2 frameshift mutations. The latter seven mutations seemed to be pathogenic.CONCLUSION: Germline mutations of hMLH1 and hMSH2 genes are identified in about one-third HNPCC kindreds fulfilling Chinese HNPCC criteria. Chinese HNPCC families have some particular clinical characteristics, such as a left-sided predominance, less synchronous or metachronous colorectal cancer, and frequent occurrence of gastric cancer.     

miR-27a通过调控Sprouty2促进胰腺癌细胞PANC-1的生长

目的探讨miR-27a在胰腺癌细胞生长过程中的作用及相关机制。方法应用RT-PCR检测胰腺癌组织中miR-27a的表达水平;应用CCK-8生长曲线和软琼脂克隆形成实验检测miR-27a对胰腺癌细胞PANC-1生长能力的影响;应用双荧光素酶报告基因实验和Westernblot筛选miR-27a的靶基因。结果 (1)相比较于癌旁正常胰腺组织,胰腺癌组织中miR-27a表达显著上调;(2)抑制胰腺癌细胞PANC-1内源性miR-27a能够显著下调癌细胞的生长活性;(3)miR-27a能够直接调控Sprouty2基因3'UTR中的MRE序列;(4)抑制PANC-1细胞内源性miR-27a能够显著上调Sprouty2蛋白35%。结论 miR-27通过调控胰腺癌细胞PANC-1中Sprouty2蛋白表达发挥癌基因功能。     

Analysis of selected oncogenes (AKT1, FOS, BCL2L2, TGFbeta) on chromosome 14 in granulosa cell tumors (GCTs): a comprehensive study on 30 GCTs combining comparative genomic hybridization (CGH) and fluorescence-in situ-hybridization (FISH)

In previous studies, we have demonstrated a number of cytogenetic alterations in granulosa cell tumors (GCTs), especially on chromosomes X, 12, 14, and 22. However, little is known about specific loci on 14q, which could play an important role in tumor pathology. Therefore, we assessed four important genes in 30 GCTs using fluorescence-in situ-hybridization (FISH). Comparative genomic hybridization (CGH) was performed on paraffin-embedded material. Then, we applied FISH with gene-specific DNA probes for AKT1 (14q32.32), FOS (14q24.3), BCL2L2 (14q11.2-q12), and TGFbeta3 (14q24), and tried to find a correlation between CGH, FISH, tumor stage, and survival. In CGH, 7 of 30 cases (23.3%) showed complete gains on chromosome 14. FISH of the four loci revealed gains of hybridization signals in 8 of 30 cases (26.6%), indicating trisomy of the whole chromosome arm. The same aberration was detected by FISH in 2 of 30 cases (6.6%), which were negative using CGH. One case (1 of 30; 3.3%) was found to have a gain on chromosome 14 by CGH, which could not be confirmed by FISH. A correlation with tumor stage or survival could not be established. Our results suggest that GCTs may be characterized by trisomy of chromosome 14. A specific oncogene that could play a particular role in the tumorigenesis of GCTs was not identified on chromosome 14.     

BMI-1基因在妇科肿瘤中的研究进展

B细胞特异的莫洛尼白血病毒插人位点1基因(B-cell specific moloney murine leukemiavirus insertion site 1,BMI-1)是多疏基因(polycomb group gene)家族重要的调节基因,被认为是癌基因.BMI-1在调节干细胞自我更新、细胞增殖和衰老中发挥重...     

肝细胞癌组织中丙型肝炎NS3蛋白对P53蛋白表达的影响

目的探讨肝细胞癌（ＨＣＣ）及其癌旁肝组织中丙型肝炎病毒（ＨＣＶ）ＮＳ３蛋白对Ｐ５３蛋白表达的影响及其在肝癌发生中的作用。方法用免疫组织化学技术检测４７例乙型肝炎病毒阴性的ＨＣＣ及其癌旁肝组织中ＨＣＶＮＳ３蛋白和Ｐ５３蛋白的表达。结果ＨＣＶＮＳ３蛋白在ＨＣＣ中的阳性率（６２％）明显低于癌旁肝组织（８３％）,Ｐ＜００２５。癌组织中其表达强度与癌细胞分化程度呈相关性（Ｐ＜００２５）。Ｐ５３蛋白在癌组织中的阳性率（８１％）明显高于癌旁组织（４７％）,Ｐ＜００２５;癌细胞分化愈差,表达愈强（Ｐ＜００５）;癌组织中Ｐ５３蛋白表达与ＨＣＶＮＳ３蛋白的表达无相关性（Ｐ＞０５）,而癌旁肝组织中两者表达呈显著相关性（Ｐ＜００１）,ＨＣＶＮＳ３蛋白阳性患者中Ｐ５３蛋白表达明显高于ＨＣＶＮＳ３阴性病例,Ｐ＜００５。结论ＨＣＶＮＳ３蛋白可能是在肝细胞转化早期通过内源性机制间接作用于Ｐ５３基因使其突变导致肝细胞癌变。     

Molecular pathology of ovarian carcinomas

 There is evidence that ovarian cancer may be derived from the progressive transformation of benign and/or borderline tumours. Mutations involving different oncogenes and tumour suppressor genes accumulate during the process of malignant transformation, and the alterations of genes involved in the pathogenesis of familial ovarian cancer are probably early events in ovarian tumorigenesis. BRCA-1 and BRCA-2 act as classical tumour suppressor genes in hereditary tumours, but their role in sporadic tumours remains controversial; however, a high frequency of allele losses in BRCA-1 (17q) and BRCA-2 (13q) loci has been observed in both familial and sporadic tumours. The possible role of mismatch repair genes and microsatellite instability is also controversial, but a role for them has been proposed in borderline tumours. Mutations in K-ras are specific for mucinous tumours and may be related to mucinous differentiation. Finally, a role in tumour progression has been proposed for both c-erb B-2 and p53, but their practical value in prognosis remains questionable. Received: 29 May 1997 / Accepted: 2 April 1998     

单亲二体及其在癌症中的作用研究进展

单亲二体（UPD）是指个体的同源染色体或其上的一部分均来自于双亲中一方的一种染色体缺陷,能够造成基因印记障碍或基因纯合突变,从而导致各类疾病,包括癌症。UPD的形成机制多样,主要由细胞分裂时染色体未正确分离所致。UPD不改变基因拷贝数,导致传统的细胞遗传学检测手段难以对其进行有效鉴定。近年来,随着单核苷酸多态性阵列等技术的出现,越来越多的UPD相关病例被检出,并发现其以非随机的形式出现在不同类型的癌症中,在癌症的发生、发展以及转移等过程中发挥重要作用。本文从UPD的形成机制、检测方法、影响区域、涉及基因、临床预后价值等方面,综述UPD在癌症中的作用研究进展,并讨论其发展趋势。     

Relationship between loss of heterozygosity of deleted in colorectal carcinoma gene microsatellites and prognosis of colorectal adenocarcinoma

AIM: To investigate the relationship between the loss of heterozygosity (LOH) of microsatellites on the deleted in colorectal carcinoma (DCC) gene and prognosis of colorectal adenocarcinoma.METHODS: A retrospective study of 58 colorectal adenocarcinoma cases with follow-up data and paired control normal mucosal tissues from 1983 to 1985 from files from the West China University of Medical Sciences Department of Pathology was carried out by PCR microsatellite analysis. Sixteen, 35, and seven cases had well-, moderately, and poorly differentiated tumors, respectively; 11, 30, and 17 cases were staged as Dukes’ A, B, and C, respectively.RESULTS: LOH of DCC microsatellites was detected in 18 cases (31.0%). The 5-year survival rate between LOH-positive and LOH-negative patients was 44.4% and 77.5%, respectively (P < 0.05). The results suggest that LOH of DCC microsatellites correlate with prognosis but not with differentiation (P > 0.05) and Dukes’ stage (P > 0.05) in colorectal adenocarcinoma.CONCLUSION: LOH of DCC microsatellites may be a marker of malignancy. Combined with the traditional prognostic indicators, LOH can predict prognosis of colorectal adenocarcinoma.