Microsatellite instability in early gastric cancer

Microsatellite replication errors (RERs), consisting in random tumour-associated allele contractions or expansions, represent a frequent genetic alteration in gastric cancer and appear to be associated with important clinicopathologic parameters. To verify the role of microsatellite instability in the initial phases of gastric carcinogenesis, we analysed the status of II microsatellites in paired microdissected samples of tumour and unaffected mucosa from 30 cases of early gastric carcinoma. Fifteen tumours (50%) demonstrated RERs: these included 7 cases with RERs at one locus and 8 cases with RERs at 2 or more loci. Cases with 2 or more RERs were more frequent among intramucosal tumours, compared to tumours with submucosal spread (43% vs. 12%) and among tumours staged T1NOMx, compared to tumours staged T1N1Mx (35% vs. 0%). RER-positive microsatellite typings were statistically more frequent among tumours with intramucosal extension, lower stage (T1NOMx) and excavated growth pattern (macroscopic type III), compared to tumours with submucosal extension, higher stage (T1N1Mx) and elevated, flat or depressed growth patterns (macroscopic types IIa-IIb-IIc respectively). The above findings indicate that microsatellite instability occurs early in the progression of sporadic gastric cancer and tends to be associated with good prognostic indicators.     

Molecular disorders in transitional vs. peripheral zone prostate adenocarcinoma.

Loss of heterozygosity (LOH) and microsatellite instability (MSI) have been shown to be mechanisms for tumor-suppressor gene inactivation in human oncogenesis. In our study, we examined LOH and MSI using 16 polymorphic markers of DNA for chromosomes 1, 3, 7, 8, 10 and 11. Microdissected tumor samples were isolated from 32 patients, representing 11 foci of incidentally discovered prostate cancer of the transitional zone (TZ), 12 prostate cancer of the peripheral zone (PZ) and 10 of high-grade PIN. We found loss of heterozygosity in the TZ group in 91% of informative cases (10/11) with al least 1 marker compared to 58% of cases (7/12) in PZ group and 70% of cases (7/10) in the HGPIN group. Chromosome 7 showed the highest rate of allelic loss in all 3 categories, with loss of 43% of loci in PIN, 37% in TZ tumors and 31% in PZ tumors. At chromosome 11, LOH was detected in 26% of loci in the TZ group, in 7% of loci in the PZ group and in 13% of loci in the PIN group. On chromosome 8, the PZ and HGPIN group showed allelic loss in 22% and 21% of loci, respectively, compared to 10% detected in the TZ group. The TZ group showed a significant higher rate of allelic instability compared to that observed in tumor samples from the peripheral zone: 73% of cases (8/11) showed genetic alterations (RER+ phenotype) in at least 4 loci analyzed compared to 8% and 10% in the PZ and HGPIN groups, respectively (p = 0.0006). These data suggest that transitional zone carcinoma and peripheral zone carcinoma display distinct and specific genetic alterations in different chromosomes. This diversity may help explain biologic and clinical differences between carcinomas arising in these distinct zones of the prostate. Also our results strongly suggest that the RER+ mutator phenotype could be linked to early development of transitional zone prostate carcinoma.     

Prognostic significance of microsatellite instability in patients with gastric carcinoma

A proportion of gastric adenocarcinomas exhibit replication errors manifested as microsatellite instability. The clinicopathological and prognostic significance of this abnormality remains uncertain. This study aimed to determine the importance of microsatellite instability by analysing a large series of gastric carcinomas from an English population. Using a novel fluorescent polymerase chain reaction technique, we amplified 11 microsatellite sequences from paired normal and carcinoma DNA from 101 patients who underwent a potentially curative resection for gastric carcinoma. Overall, 21% of cases demonstrated microsatellite instability in at least one locus. At least four loci were examined in each case. A replication error positive phenotype (minimum of 29% of loci affected) was detected in 9% of cases. There was no statistically significant association between the presence of microsatellite instability or replication error positive phenotype and the patient's age, sex, tumour site, stage, node status, histological subtype or grade. Carcinomas confined to the mucosa or submucosa (T1) showed a significantly higher frequency of instability and replication error positive phenotypes than T3 lesions (P=0.03 and P=0.05, respectively). A larger proportion of patients who were microsatellite instability or replication error positive were alive at 5 years compared with those who were negative but this did not reach statistical significance (P=0.15 and P=0.16, respectively). We identified a subset of gastric carcinomas from a relatively low-risk population which showed evidence of microsatellite instability. There were no statistically significant 5-year survival advantages in cases demonstrating microsatellite instability or replication error positive phenotypes. The detection of microsatellite instability is of limited prognostic value in gastric carcinoma.     

Genetic instability in lung cancer: concurrent analysis of chromosomal, mini- and microsatellite instability and loss of heterozygosity

To investigate what kind of genetic instability plays important roles in lung carcinogenesis, we analyzed micro- and minisatellite instability, loss of heterozygosity (LOH) and chromosome instability in 55 cases of lung cancer, including, 10 squamous cell, 5 large cell, and 3 small cell carcinomas, and 37 adenocarcinomas. Analysis of minisatellite instability, the mechanism of which is different from microsatellite instability, has not been reported previously. Minisatellite instability was detected in only one case (1/55, 1.8%), and the frequency of microsatellite instability was low, being found only in three cases (3/55, 5.5%). In contrast, LOH, for at least in one locus, was observed in 27 cases (49.1%). In adenocarcinomas, the frequency of LOH was higher in poorly differentiated compared to more differentiated carcinomas. For chromosome instability, a similar correlation between differentiation grade and instability was observed in adenocarcinomas. And instability was more common in large cell and small cell carcinomas than in adenocarcinomas. Our analysis showed that chromosome instability and LOH, rather than mini- and microsatellite instability, play significant roles in the development of lung cancer.     

Epigenetic inactivation of IkappaB Kinase-alpha in oral carcinomas and tumor progression.

PURPOSE: The loss of epithelial phenotypes in the process of carcinoma progression correlates with clinical outcome, and genetic/epigenetic changes accumulate aggressive clones toward uncurable disease. IkappaB kinase-alpha (IKKalpha) has a decisive role in the development of the skin and establishes keratinocyte phenotypes. We assessed clinical implications of IKKalpha expression in oral carcinomas and epigenetic aberrations for the loss of expression. EXPERIMENTAL DESIGN: We examined IKKalpha expression in oral carcinomas by immunostaining (n = 64) and genetic instability by microsatellite PCR (n = 46). Promoter methylation status was analyzed by bisulfite-modified sequence (n = 11). RESULTS: IKKalpha was expressed in the nucleus of basal cells of normal oral epithelium, but not or marginally detected in 32.8% of carcinomas. The immunoreactivity was significantly decreased in less differentiated carcinomas (P < 0.05) and correlated to long-term survival of patients (P < 0.01) with an independent prognostic value (P < 0.05). Although allelic/biallelic loss of the gene was limited to four cases, we detected microsatellite instability in 63.0% cases in which the immunoreactivities were decreased and the promoter was hypermethylated. CONCLUSION: These results showed that oral carcinomas exhibiting genetic instability and promoter hypermethylation down-regulate expression of IKK and suggest that the epigenetic loss of the expression closely associates with disease progression toward unfavorable prognosis.     

甲状腺未分化癌

甲状腺未分化癌较少见。我们从１９７７年～１９９０年共收治甲状腺癌３７２例，未分化癌仅１１例，占３％。病理类型分为梭形细胞巨细胞型和小细胞型。此型癌以恶性程度高为特点，治疗很困难。作者采用手术＋放疗＋化疗提高了疗效，本组生存５年者３例，占２７．３％；存活２年３例；１／２以上的病人存活超过２年。     

胃粘膜肠化与胃癌关系的粘液组织化学研究

本文应用粘液组织化学技术，对117例胄癌、62例慢性胃炎伴（肠化生）组织的粘液分泌进行观察。根据所含粘液不同，将胄癌分为肠型及胃型，将畅化分为大肠型及小肠型。肠型胃癌的肠化检出率显著高于胃型胃癌（P＜0．01）。大肠型肠化在肠型胃癌旁肠化检出率显著高于在胄型胄癌旁肠化及慢性胃炎伴肠化的检出率（P＜0．01）。肠型胃癌的发生与胄粘膜肠化，特别与大肠型肠化关系密切。因此，加强对大肠型肠化的密切随访．有利于胃癌的早期发现。     

p53 mutation profiling of multiple esophageal carcinoma using laser capture microdissection to demonstrate field carcinogenesis

Inactivation of the p53 tumor suppressor gene is one of the most frequent genetic alterations observed in human esophageal carcinomas. In patients with esophageal carcinoma, one of the significant pathological features of the tumor is the presence of multiple lesions within the esophagus. However, the molecular mechanisms involved in the occurrence of multiple lesions have remained elusive. To characterize p53 alterations in multiple esophageal carcinomas and to study their roles in carcinogenesis, we performed p53 immunohistochemical and p53 mutation analyses using laser capture microdissection on surgically resected human esophageal carcinomas from 11 patients: 9 patients with multiple esophageal carcinomas, 1 with an intramural metastasis lesion within the esophagus and 1 with an intraepithelial carcinoma lesion contiguous to the main lesion. In each of the patients with multiple esophageal carcinomas, we examined samples from 1 main lesion and 1 representative concomitant lesion. Molecular analyses of samples from fresh-frozen normal tissues and tumor tissues of the main lesion (whole tumor) were also performed by the same method. p53 protein accumulation was observed in 16 (72.7%) of 22 lesions from the 11 cases. No p53 mutation was found in normal esophageal tissues. In the 9 cases of multiple esophageal carcinomas, point mutations were detected in the whole tumor in 1 (11.1%) case, in the microdissected tumor samples of main lesions in 3 (33.3%) cases and in the microdissected tumor samples of concomitant lesions in 3 (33.3%) cases. For the microdissected tumor samples, there was a 54.5% (12/22) concordance rate between the results of immunostaining and molecular analysis. In the 8 cases of whole tumors in which a p53 mutation was not observed, 2 cases revealed p53 mutation in the microdissected tumor samples of the main lesion. All 6 cases of multiple esophageal carcinomas that showed a p53 mutation in the microdissected tumor sample had a discordant p53 mutational status between the main and concomitant lesions. In contrast, both the intramural metastasis lesion and the intraepithelial carcinoma contiguous to the main lesion showed p53 mutational patterns identical to those of the main lesions. In conclusion, the analysis of microdissected DNA by laser capture microdissection is useful for characterizing the heterogeneity of the p53 gene mutation in multiple carcinoma lesions that cannot be accurately analyzed in whole esophageal tumor DNA. The finding of different p53 gene mutations among multiple esophageal carcinoma lesions suggest further evidence of multicentric or field carcinogenesis of the human esophagus.     

The molecular genetics of cervical carcinoma.

In the pathogenesis of cervical carcinoma there are three major components, two of them related to the role of human papillomaviruses (HPV). First, the effect of viral E6 and E7 proteins. Second, the integration of viral DNA in chromosomal regions associated with well known tumour phenotypes. Some of these viral integrations occur recurrently at specific chromosomal locations, such as 8q24 and 12q15, both harbouring HPV18 and HPV16. And third, there are other recurrent genetic alterations not linked to HPV. Recurrent losses of heterozygosity (LOH) have been detected in chromosome regions 3p14-22, 4p16, 5p15, 6p21-22, 11q23, 17p13.3 without effect on p53, 18q12-22 and 19q13, all of them suggesting the alteration of putative tumour suppressor genes not yet identified. Recurrent amplification has been mapped to 3q+ arm, with the common region in 3q24-28 in 90% of invasive carcinomas. The mutator phenotype, microsatellite instability, plays a minor role and is detected in only 7% of cervical carcinomas. The development of cervical carcinoma requires the sequential occurrence and selection of several genetic alterations. The identification of the specific genes involved, and their correlation with specific tumour properties and stages could improve the understanding and perhaps the management of cervical carcinoma.     

Different Clinicopathologic Findings in Two Histologic Types of Carcinoma of Papilla of Vater

The aim of this study was to investigate the differences between the clinicopathological findings in two histologic types of carcinoma of the papilla of Vater. We histologically classified carcinoma of the papilla into two types: 1) an intestinal type that resembles tubular adenocarcinoma of the stomach or colon, and 2) a pancreaticobiliary type that is characterized by papillary projections with scant fibrous cores. We examined 53 cases of resected carcinoma of the papilla. The intestinal-type carcinomas were similar to the intestinal mucosa in that they had lysozyme-containing, Paneth or argyrophil cells, as demonstrated by the immunohistochemically positive stainings for the anti-lysozyme antibody. Although both the sizes of the two types of carcinomas and the age distributions of cases with the two types of carcinoma were almost the same, the prognosis of the cases with the intestinal type was much better than that of the cases with the pancreaticobiliary type. Histological lymph node metastasis was found significantly more often in the pancreaticobiliary type. This result was supported by the fact that small carcinomas of the intestinal type showed little or no invasion into the surrounding interstitium, as opposed to the pancreaticobiliary type, which had a strong infiltrative tendency. The pathogenesis of carcinoma of the papilla of Vater should be further evaluated, taking into consideration the existence of these two histologic types.     

大肠癌MDR—1与p53表达关系及其意义

目的探讨大肠癌中多药耐药基因ＭＤＲ１与ｐ５３表达之间的关系。方法利用免疫组化研究６０例大肠癌及２０例大肠腺瘤ＭＤＲ－１,ｐ５３的表达。结果显示６０例大肠癌切片中ＭＤＲ－１与ｐ５３的阳性表达率为５７％和３７％,１０例正常大肠组织和２０例大肠腺瘤仅２０％显示ＭＤＲ－１阳性表达,ｐ５３在正常大肠组织,管状腺瘤中全部阴性,仅一例有不典型增生的绒毛状腺瘤为阳性表达。同时显示ｐ５３在不同分化的大肠癌中与ＭＤＲ表达呈正相关。结论１）通过检测ＤＭＲ－１可以对大肠癌病人进行化疗敏感性预测。２）ｐ５３过度表达对ＭＤＲ－１基因可能具有诱导和增加效应。３）ｐ５３和ＭＤＲ－１一起可用作判断病人预后,生物学行为的一个有用参数。     

Coding microsatellite instability analysis in microsatellite unstable small intestinal adenocarcinomas identifies MARCKS as a common target of inactivation

Approximately 15% of small intestinal adenocarcinomas show inactivation of DNA‐mismatch repair (MMR) and display high‐level microsatellite instability (MSI‐H). MSI‐H tumors progress as a result of mutations affecting coding microsatellites (coding microsatellite instability, cMSI) that may result in a functional inactivation of the encoded proteins and provide a selective growth advantage for the affected cell. To investigate the cMSI selection in small intestinal carcinogenesis 56 adenocarcinomas were tested for MSI. Eleven MSI‐H carcinomas (19.6%) were identified and subjected to cMSI analysis in 24 potentially tumor relevant genes. Mutation frequencies were similar to those observed in colorectal cancer (CRC). Beside high frequencies of cMSI in TGFβR2, ACVR2, and AIM2 we detected MARCKS mutations in 10 out of 11 (91%) tumors with a 30% share of biallelic mutations. Since little is known about MARCKS expression in the intestine, we analyzed MARCKS protein expression in 31 carcinomas. In non‐neoplastic mucosa, MARCKS was found to be expressed with a concentration gradient along the crypt–villus axis. In line with cMSI induced functional inactivation of MARCKS, 8 out of 11 MSI‐H adenocarcinomas showed regional or complete loss of the protein. In microsatellite stable (MSS) small bowel adenocarcinoma, loss of MARCKS expression was seen in 2 out of 20 tumors (10%). In conclusion, we herein present a cMSI profile of MSI‐H small intestinal adenocarcinomas identifying MARCKS as a frequent target of mutation. Loss of MARCKS protein expression suggests a significant role of MARCKS inactivation in the pathogenesis of small intestinal adenocarcinomas. © 2009 Wiley‐Liss, Inc.     

缺氧诱导因子-1在胰腺癌组织中的表达及临床意义

目的:探讨缺氧诱导因子(HIF-1α)在胰腺癌组织中的表达及其临床意义。方法:应用免疫组化技术检测HIF-1α蛋白在48例胰腺癌组织和5例正常胰腺组织中的表达情况,并分析其与临床病理因素及预后之间的关系。结果:HIF-1α蛋白在48例胰腺癌组织中的阳性表达率为52.1%(25/48),而在5例正常胰腺组织中均未见表达,两者间差异有统计学意义(P<0.01)。HIF-1α表达与肿瘤体积(P=0.015)及TNM分期呈正相关(P=0.021),与预后呈负相关(10.4%vs 4.0%,P=0.027);而与胰腺癌的部位、病理分级等无关(P>0.05)。结论:HIF-1α在胰腺癌的发生发展过程中起着重要作用,可作为判断胰腺癌预后的有用指标。     

谷胱甘肽S转移酶在人肺癌的表达

应用PAP免疫组化技术,观察了谷胱甘肽S转移酶(GST)在84例肺癌的表达,并与23例肺非癌病变对照.结果发现,碱性、中性、非酸性GST很少在肺癌及肺非癌病变表达.酸性GST在鳞癌、腺癌、腺鳞癌、小细胞癌及类癌的阳性率分别为93.5％、66.7％、83.3％、7.1％、18.2％,而极少在肺非癌病变表达.故酸性GST可能是肺鳞癌、腺癌、腺鳞癌的标志酶,在与肺非癌病变的鉴别上为有用指标.     

Allele loss in human gastric carcinomas - relation to tumor progression and differentiation

The sequence of genetic changes associated with the development of gastric carcinoma remains unclarified despite the numerous genetic and chromosomal abnormalities that have been implicated so far in this process. We investigated the frequency and pattern of allele loss in 68 gastric carcinomas, with the aim of identifying genetic changes putatively involved in the histologic differentiation and/or progression of gastric cancer. Allele loss was investigated using 12 RFLP and 11 microsatellite markers localized at 22 different loci from 9 autosomal chromosomes. Allele loss in at least one chromosome arm was detected in 41 out of the 68 cases (60%). A high ratio of allele loss was significantly associated with the masculine gender and aneuploidy. The chromosome arms most commonly affected were 3p (57%), 17p (44%), and 6q (32%). Alterations at these chromosome arms were also frequently found (greater than or equal to 40%) in the six less advanced gastric carcinomas of the series, thus suggesting that genetic changes involving these chromosomes are early events in gastric tumorigenesis. Genetic changes at 5q and 17p loci were only observed in gastric carcinomas of the intestinal and atypical (unclassified) types, thereby indicating a possible role of genes located at these chromosome arms in the differentiation of gastric carcinoma.     

Microsatellite alterations in superficial and locally advanced transitional cell carcinoma of the bladder.

Recent studies described the existence of genetic instability associated with bladder carcinogenesis. Alterations at microsatellite loci constitute a recognized tumor marker of genome instability. A series of 21 transitional cell carcinomas of the bladder (10 superficial and 11 invasive carcinomas) was analyzed for the presence of alteration in 12 microsatellite loci, in order to detect the role of microsatellite instability in genesis and progression of human bladder cancer. Our preliminary results indicate a trend to presence of microsatellite instability (MI) in invasive and undifferentiated tumors compared to superficial and differentiated forms. Eight out of 11 T2-T4 tumors presented a number of altered microsatellite >/=2 compared to one out of 10 Ta-T1 bladder carcinomas (p=0.008). Moreover, 9 out of 15 (60%) G2-G3 tumors had significantly more unstable microsatellites than those differentiated (0 out of 6) (p=0.019). Our results provide an insight into the potential usefulness of microsatellite analysis of bladder carcinoma to better understand which neoplastic forms will evolve to invasive progression and indicate that pronounced MI may be associated with more aggressive bladder carcinomas.     

Cardia carcinomas of intestinal type are associated with histologic changes in the gastric mucosa

Background. Previous studies of Japanese patients showed that distal gastric carcinomas (of the corpus or the antrum) were associated with histologic changes in the non-neoplastic gastric mucosa. These changes (cells with ciliated metaplasia, with large and small mucus-negative vacuoles, intramucosal glandular cysts, and extensive intestinal metaplasia) were often found in carcinomas of intestinal type. Methods. In the present work, similar mucosal changes were searched for in surgical specimens carrying a carcinoma of the cardia. A total of 12 079 archival histologic sections, corresponding to 563 gastrectomies performed in Japanese patients, were analyzed. Results. Of the specimens with cardia carcinoma of intestinal type seen in Tokyo (n = 169) and in Matsuyama (n = 168), 53.3% and 63.1% contained intramucosal cysts; 39.6% and 51.8%, ciliated metaplastic cells; 34.9% and 30.4%, large vacuolated cells; and 7.7% and 11.9%, small vacuolated cells; and 69.8% and 68.5% had high intestinal metaplasia scores, respectively. These percentages were significantly higher than those for cardia carcinomas of diffuse type in Tokyo (n = 153) and in Matsuyama (n = 73), in which 30.7% and 34.2% of the specimens had intramucosal cysts; 17.6% and 17.8%, ciliated metaplastic cells; 14.4% and 9.6%, large vacuolated cells; and 3.9% and 4.1%, small vacuolated cells; and 43.1% and 39.7% had high intestinal metaplasia scores, respectively. Conclusion. Thus, similarly to carcinomas of the corpus or the antrum, cardia carcinomas of intestinal type are associated with histologic changes in the gastric mucosa. The possibility that these changes are evoked by environmental factors was entertained. Received on July 21, 1999; accepted on Jan. 5, 2000     

原发性食管小细胞未分化癌：附15例分析

本文分析原发性食管小细胞未分化癌15例,发生率占同期收治食管癌2121例的0.71％。本病主要见于中老年男性,中位年龄57岁,男性11例,女性4例。吞咽困难是最常见的症状,中位症状期2个月。食管上段1例,中段8例,下段6例。溃疡型6例,髓质型5例,缩窄型3例,蕈伞型1例。病灶长3.5cm～10cm,平均6.0cm。单纯小细胞癌型13例,混合鳞癌型1例,双重癌1例。15例中手术探查12例,其中切除7例,短路2例,单纯探查术3例。12例均给予辅助化疗,选用CCOM方案。放疗加化疗1例,单纯化疗2例。15例均随访,13例死亡,1例失访,1例尚在治疗中。14例中位生存期7个月。手术切除加化疗组7例中,2例最长生存20个月,中位生存期11个月。手术切除加辅助化疗,略优于其它治疗组。     

Prevalence of microsatellite instability,inactivation of mismatch repair genes,p53 mutation,and human papillomavirus infection in Korean oral cancer patients

To determine the etiologic factors of human oral cancer, we examined the prevalence of microsatellite instability (MSI), the inactivation of mismatch repair (MMR) genes, p53 mutation, and human papillomavirus (HPV) infection (HPV-16, -18, and -33) in 86 Korean oral cancer specimens, including 76 squamous cell carcinomas and 10 salivary gland tumors. MSI was observed in 3 of the 76 squamous cell carcinomas (4%) and 2 of 10 salivary gland tumors (20%). As MSI is a hallmark of the inactivation of the MMR genes, the genetic status of hMSH2 and hMLH1, and hypermethylation of the hMLH1 promoter region were investigated in oral cancers displaying MSI. Inactivation of the hMLH1 gene by either mutation or hypermethylation was observed 4 of the 5 MSI oral cancers. Mutation of the p53 gene was found in 11 of 76 squamous cell carcinomas (14.5%) but not in the salivary gland tumors. PCR assay revealed the presence of HPV DNA in 11 of the 76 squamous cell carcinomas (14.5%) and 4 of the 10 salivary gland tumors (40%). Type 18 HPV DNA was predominant in 11 of the HPV-infected squamous cell carcinomas (72.7%) and 4 of the HPV-infected salivary gland tumors (50%). Two squamous cell carcinoma tissues were found both to be HPV-infected and to harbor the p53 mutation. Our results suggest: i) that MSI plays a role in the pathogenesis of Korean oral cancers, squamous cell carcinomas (4%) and salivary gland tumors (20%); ii) that genetic alteration or hypermethylation of the hMLH1 gene may be the principal inactivating mechanism in Korean oral cancer with MSI; and iii) that inactivation of the p53 gene by either mutation or HPV infection is frequent in Korean squamous cell carcinomas (26%) and salivary gland tumors (40%).