EXPRESSION OF p16,CYCLIN D1 AND RB PROTEIN IN GASTRIC CARCINOMA AND PREMALIGNANT LESIONS

Gastric carcinoma is one of the most serious diseases in mankind. Its pathogenesis has not been understood very clearly. Recent researches suggested that oncogenes (such as cyclin D1), antioncogenes (ie., p16, Rb) and cell cycle played an important role in the pathogenesis of gastric carcinoma. But there are few reports about the relationship between these genes in gastric carcinoma and gastric premalignant lesions. In this study, we will discuss these problems. MATERIALS AND METHO…     

Monocyte chemoattractant protein‐1 is generated via TGF‐β by myofibroblasts in gastric intestinal metaplasia and carcinoma without H. pylori infection

Helicobacter pylori (H. pylori) stimulates secretion of monocyte chemoattractant protein 1 (MCP‐1) from gastric mucosa. Monocyte chemoattractant protein‐1 (MCP‐1) expression and macrophage infiltration are recognized in human gastric carcinoma. We have previously generated Cdx2‐transgenic mice as model mice for intestinal metaplasia. Both chronic H. pylori‐associated gastritis and Cdx2‐transgenic mouse stomach develop intestinal metaplasia and finally gastric carcinoma. In this study we have directed our attention to MCP‐1 expression in the intestinal metaplastic mucosa and the gastric carcinoma of Cdx2‐transgenic mouse stomach. Quantitative real‐time PCR was performed to determine MCP‐1 and transforming growth factor‐β1 (TGF‐β1) mRNA expression levels and single‐ or double‐label immunohistochemistry was used to evaluate the localization of MCP‐1, TGF‐β type I receptor, and α‐smooth muscle actin (αSMA). We determined that MCP‐1 mRNA dramatically increased in the intestinal metaplastic mucosa and the gastric carcinoma of Cdx2‐transgenic mouse stomach, compared with normal mouse stomach. Both MCP‐1 and TGF‐β type I receptor were co‐expressed in the αSMA‐positive myofibroblasts of intestinal metaplastic mucosa and gastric carcinoma. Exogenous application of TGF‐β1 increased MCP‐1 mRNA expression levels in the intestinal metaplastic tissue. Furthermore, TGF‐β1 was overexpressed and macrophage was strongly infiltrated in the gastric carcinoma. In conclusion, MCP‐1 expression, which was stimulated by TGF‐β1, was recognized in the TGF‐β type I receptor‐expressing myofibroblasts of the intestinal metaplastic mucosa and the gastric carcinoma of Cdx2‐transgenic mouse stomach. The present results suggest that intestinal metaplasia and gastric carcinoma themselves induce MCP‐1 expression independently of H. pylori infection. (Cancer Sci 2010)     

Numerical aberration and point mutation of p53 gene in human gastric intestinal metaplasia and well-differentiated adenocarcinoma: Analysis by fluorescence in situ hybridization (FISH) and PCR-SSCP

This study examined p53 gene alterations in human gastric mucosa, intestinal metaplasia and well-differentiated (cohesive type) adenocarcinomas to clarify to the role of the p53 gene in gastric tumorigenesis by means of fluorescence in situ hybridization (FISH), polymerase-chain-reaction-single-strand-conformation polymorphism (PCR-SSCP) and immunohistochemistry. Gene alterations were compared with numerical changes of chromosome 17. Samples were obtained from 31 surgically resected stomachs affected with gastric cancer. There was no nuclear p53 protein in cells from normal gastric mucosa. Among 23 specimens of intestinal metaplasia, cells with p53 protein were variably detected in 5 incomplete metaplasias (colonic type). A histological study revealed a mildly dysplastic appearance. PCR-SSCP identified p53-gene mutation in exons 5 and 8 in 2 of the 5 samples. Numerical aberrations of chromosome 17 and the p53 gene were undetectable both in normal mucosa and in intestinal metaplasia. Variable numbers of tumor cells contained p53 protein in 13 (54%) of 24 carcinomas, and PCR-SSCP revealed abnormal bands in 5 of them. Mutations were detected in exons, 5, 7, 7, 7 and 8. FISH analysis demonstrated that 6 carcinomas emitted 3 or 4 signals for chromosome 17, and 7 gave one signal for the p53 gene in over 20% of the cells. Ten (77%) of 13 carcinomas examined by FISH appeared to show a p53-gene deletion. © 1996 Wiley-Liss, Inc.     

胃癌、癌前病变组织中p53蛋白表达的临床意义

目的探讨胃癌及癌前病变组织中p53蛋白表达的临床意义.方法采用间接免疫荧光标记染色和流式细胞术,检测并比较10例正常胃粘膜、13例浅表性胃炎、10例肠上皮化生、11例不典型增生及16例胃癌组织中p53蛋白的表达水平.以DNA指数、增殖指数(PI)、荧光指数(FI)为分析指标.结果胃癌、不典型增生及肠上皮化生的FI值分别为1.866±0.096、1.143±0.060、1.050±0.074,与正常胃粘膜(0.602±0.077)比较,均有显著性差异(P＜0.05),与浅表性胃炎(0.898±0.052)比较,也有显著性差异(P＜0.05).胃癌组织的FI值高于不典型增生及肠上皮化生(P＜0.05).不典型增生组织p53蛋白阳性率为25.0%(2/8),胃癌为68.4%(13/19),在不典型增生及胃癌组织中,其异倍体的FI值、PI值和p53蛋白阳性率与二倍体者比较,均有显著性差异(P＜0.05).结论胃癌组织p53蛋白的表达水平高于癌前病变及正常胃粘膜组织;随病变向恶性转化,p53蛋白表达水平、PI值及异倍体率均增高.因此,检测p53蛋白表达水平对胃癌的诊断具有一定意义.     

p27蛋白及cyclin B1在慢性胃病及胃癌患者胃粘膜中的表达及其临床意义

目的 研究p27蛋白及cyclin B1在慢性胃病及胃癌患者胃粘膜组织中的表达水平,探讨p27蛋白及cyc-lin B1的表达与胃癌演变的关系.方法 采用免疫组织化学SP法,检测慢性非萎缩性胃炎、慢性萎缩性胃炎、肠上皮化生、非典型增生及胃癌患者胃粘膜组织中p27与cyclin B1的表达水平,并进行临床分析.结果 在慢性非萎缩性胃炎、慢性萎缩性胃炎、肠上皮化生、非典型增生、胃癌的演变过程中,p27蛋白表达水平呈现逐级降低的变化规律,cyclin B1表达水平呈现逐级升高的变化规律,两者的变化呈负相关.结论 p27蛋白及cyclin B1在胃粘膜中的表达水平与慢性胃病、胃癌前病变、胃癌的发生发展有关,其在胃癌的演变过程中起着重要的作用.     

CpG island methylation in premalignant stages of gastric carcinoma

There are limited reports on methylation analysis of the premalignant lesions of gastric carcinoma thus far. This is despite the fact that gastric carcinoma is one of the tumors with a high frequency of CpG island hypermethylation. To determine the frequency and timing of hypermethylation during multistep gastric carcinogenesis, non-neoplastic gastric mucosa (n = 118), adenomas (n = 61), and carcinomas (n = 64) were analyzed for their p16, human Mut L homologue 1 (hMLH1), death-associated protein (DAP)-kinase, thromobospondin-1 (THBS1), and tissue inhibitor of metalloproteinase 3 (TIMP-3) methylation status using methylation-specific PCR. Three different classes of methylation behaviors were found in the five tested genes. DAP-kinase was methylated at a similar frequency in all four stages, whereas hMLH1 and p16 were methylated in cancer samples (20.3% and 42.2%, respectively) more frequently than in intestinal metaplasia (6.3% and 2.1%, respectively) or adenomas (9.8% and 11.5%, respectively). However, hMLH1 and p16 were not methylated in chronic gastritis. THBS-1 and TIMP-3 were methylated in all stages but showed a marked increase in hypermethylation frequency from chronic gastritis (10.1% and 14.5%, respectively) to intestinal metaplasia (34.7% and 36.7%, respectively; P < 0.05) and from adenomas (28.3% and 26.7%, respectively) to carcinomas (48.4% and 57.4%, respectively: P < 0.05). The hMLH1, THBS1, and TIMP-3 hypermethylation frequencies were similar in both intestinal metaplasia and adenomas, but the p16 hypermethylation frequency tended to be higher in adenomas (11.5%) than in intestinal metaplasia (2.1%; P = 0.073). The average number of methylated genes was 0.6, 1.1, 1.1, and 2.0 per five genes per sample in chronic gastritis, intestinal metaplasia, adenomas, and carcinomas, respectively. This shows a marked increase in methylated genes from non-metaplastic mucosa to intestinal metaplasia (P = 0.001) as well as from premalignant lesions to carcinomas (P = 0.002). These results suggest that CpG island hypermethylation occur early in multistep gastric carcinogenesis and tend to accumulate along the multistep carcinogenesis.     

胃癌及胃癌前病变p53蛋白、PCNA表达及其临床意义的研究

目的探讨p53蛋白、增殖细胞核抗原(PCNA)在胃癌及胃癌前病变发生发展中的作用及其临床意义.方法采用免疫组织化学技术(S-P法).结果胃癌及胃癌前病变中p53蛋白、PCNA表达水平均高于正常胃粘膜(P＜0.05).表达水平从肠上皮化生、异型增生到胃癌均呈递增趋势.其在胃癌组织中的表达与组织类型、侵润深度、淋巴结转移密切相关(P＜0.05).结论 p53蛋白、PCNA表达对评估胃癌前病变发展趋势和判断胃癌预后具有重要临床价值.     

Alterations of Rb, p16(INK4A) and cyclin D1 in the tumorigenesis of oral squamous cell carcinomas

Immunohistochemical analysis of Rb, p16(INK4A) and cyclin D1 expression was performed on 78 oral squamous cell carcinoma (SCC), 46 leukoplakia, and 20 normal mucosa. Rb and p16(INK4A) expression were observed in all normal mucosa and most of leukoplakia. Lack of Rb and p16(INK4A) was observed in 56.4 and 67.9% of SCC, respectively. The overexpression of cyclin D1 was not observed in normal mucosa and was observed in 35.9% of SCC. A strong reciprocal relationship between Rb and p16(INK4A) expression was observed in oral SCC, and all these SCC cases have at least one of the alterations in the Rb pathway.     

p16和Rb蛋白在胃癌中的表达及其意义

目的 探讨胃癌组织中ｐ１６和Ｒｂ蛋白表达及其与临床病理的关系。方法 采用免疫组织化学方法检测了４０例胃癌组织中ｐ１６和Ｒｂ蛋白的表达。结果 在胃癌组织中，ｐ１６和Ｂｂ蛋白表达阳性率分别为３５．０％（１４／４０）和７２．５％（２９／４０），ｐ１６蛋白阳性胃癌的Ｒｂ蛋白阳性率明显低于ｐ１６蛋白在中中的表达类型、淋巴结转移密切相关。结论 ｐ１６和Ｒｂ蛋白在胃癌中的表达下降与肿瘤的进展密切相关，ｐ１６蛋白     

Expressions of cyclin D1 and p27kip1 in carcinogenesis of stomach mucosa

Objective  To evaluate the relationship between the expressions of cyclin D1 and p27^kip1 in the canceration course of the stomach. Methods  The immunohistochemical staining technique (SP method) was used to detect the expressions of cyclin D1, p27^kip1 in chronic superficial gastritis (CSG), chronic atrophic gastritis (CAG), intestinal metaplasia (IM), dysplasia (DYS), gastric carcinoma (GCA) biopsy specimens. Results  The positive cyclin D1 expression rates increased with the progressing from CAG→IM→DYS→GCA respectively, and those in IM, DYS and GCA were different from those in CSG, P < 0.05, while DYS group was indifferent from GCA group, P > 0. 05. The positive p27^kip1 expression rates decreased with the mucosa progressing from CAG→IM→DYS→GCA. There was a negative correlation between the expression cyclin D1 and p27^kip1 (Y = −0.53, P = 0.000). Conclusion  Expression rates of cyclin D1 in the canceration course of the stomach mucosa trend were increased and those of p27^kip1 were decreased; the abnormal expressions of them were found in the early term of the canceration course of the stomach mucosa, and the inverse expression suggests there may be a negative feedback regulatory loop between cyclin D1 and p27^kip1.     

Expression and significance of p53 and mdm2 in atypical intestinal metaplasia and gastric carcinoma

Subtypes of intestinal metaplasia may have different manifestations in the carcinogenesis of gastric mucosa. The present study aimed to investigate expression of murine double minute gene 2 (mdm2) in atypical intestinal metaplasia (AIM) and its relationship to gastric carcinoma. Intestinal metaplasia (IM) specimens were obtained from 58 cases. Using a novel classification of IM, the specimens were classified according to morphological changes exhibited in the gastric mucosa; specifically, atypical intestinal metaplasia (AIM) and simple intestinal metaplasia (SIM). The gatric carcinoma specimens were then compared with types I, II and III IM based on different substances present in the mucous. Envision immunohistochemical technique was applied to the detection of the expression of p53 and mdm2 in 58 IM and 30 gastric carcinoma cases. Expression of both p53 and mdm2 proteins was found to be higher in gastric carcinomas (p53, 56.67%, 17/30 and mdm2, 53.33%, 16/30) and AIM (p53, 51.85%, 14/27 and mdm2, 51.85%, 14/27) as compared to SIM (p53, 25.81%, 8/31 and mdm2, 19.35%, 6/31) (P<0.05). A similar pattern of expression of mdm2 protein was found in type I (36.84%, 7/19), type II (38.46%, 10/26) and type III (23.08%, 3/13) IM and gastric carcinoma (53.33%, 16/30). p53 expression was higher in gastric carcinoma (56.67%) compared to type I IM (26.32%) (P<0.05). However, no differences were evident among type II (42.31%, 11/26), type III (46.15%, 6/13) IM and gastric carcinoma. AIM may reveal the precancerous nature of gastric carcinoma more clearly than SIM or the conventional IM subtypes. Additionally, AIM may be involved as a preneoplastic lesion and therefore be an effective indicator in the clinical follow-up of gastric carcinoma patients.     

p21~(WAF1)基因在胃癌及癌前病变中表达的临床病理意义

 目的 探讨ｐ２１ＷＡＦ１蛋白表达与胃癌发生、发展、浸润转移及临床分期的关系。方法 采用 Ｓ－Ｐ免疫组化法，分别检测２０例正常胃粘膜、４０例不典型增生胃粘膜和１０８例胃癌ｐ２１ＷＡＦ１蛋白表达。结果ｐ２１ＷＡＦ１阳性表达率：正常与不典型增生胃粘膜分别为 １００％、９２％，显著高于胃癌 ３９％（Ｐ ＜０．０５）；高分化腺癌６３％，分别与低分化腺癌３５％、未分化癌２６％、粘液癌３０％及印戒细胞癌２０％比较，皆具有显著性差异（Ｐ＜０．０５）；临床Ⅰ期６０％和Ⅱ期５６％显著高于Ⅲ期２７％和Ⅳ期２２％（Ｐ＜０．０５）；伴淋巴结转移３５％与未转移６２％有显著差异（Ｐ＜ ０．０５）；浸润浅肌层 ６０％较浸润深肌层 ３５％差异有显著性意义（Ｐ＜ ０．０５）而与性别、年龄无关。结论ｐ２１ＷＡＦ１蛋白失表达与胃癌发生、分化程度、浸润、淋巴结转移及临床分期相关。     

用BC2单抗检测胃癌及癌前病变组织中MUC1基因表达及其意义

 目的　揭示胃癌及肠化组织中MUC1基因的表达与其临床病理行为之间的联系。方法　用BC2抗体和免疫组化SP法检测人正常胃肠道粘膜、肠化粘膜以及胃癌组织中MUC1基因核心肽的表达。结果　人正常胃粘膜组织中广泛分布MUC1基因产物(100%),抗原主要位于上皮层和胃腺的中下部;肠化和胃癌组织中的表达阳性率分别为79.3%和82.6%;胃癌组织中MUC1基因表达与患者的性别、部位、大小、淋巴结转移、分化类型、浸润深度、临床分期和Lauren氏分型之间无关(P>0.05);但MUC1基因强阳性者与中弱阳性者之间的临床分期存在明显的差别(P<0.05),表达越强,Ⅰ～Ⅱ期的可能性越小;不同类型肠化中MUC1基因的表达无差异(P>0.05)。结论　上述结果提示用BC2抗体检测的MUC1基因可能是胃癌进展的有用标志,可能与胃癌患者的临床病理行为之间有关,而与肠化分型无关。     

Carcinogenesis of intestinal-type gastric cancer and colorectal cancer is commonly accompanied by expression of brain (fetal)-type glycogen phosphorylase.

Our previous studies have demonstrated the significant enzymatic activity of glycogen phosphorylase (GP) in the gastric carcinoma and proliferating cells of particular intestinal metaplasia (IM). This paper reviewed the identification of the GP isoform in the gastrointestinal carcinoma, and the investigation on the role of this molecule in the gastrointestinal carcinogenesis. The only isoform expressed in gastric cancer was brain-type GP (BGP) using polymerase chain reaction (PCR) analysis. The expression of BGP, oncogene products and proliferating cell nuclear antigen in the gastric and colorectal carcinomas, their premalignant lesions, and the normal mucosa were examined using 136 gastric and 96 colorectal surgically resected specimens, and 55 endoscopically resected colorectal adenomas. The BGP visualized by immunohistochemistry was commonly present in intestinal-type gastric (80.6%) and colorectal (83.3%) carcinomas, whereas no BGP expression was seen in the normal human gastric and large intestinal mucosa except in the BGP foci described below. IMs with BGP had close correlation with intestinal-type gastric carcinoma, and some of them coexpressed accumulated p53 protein. The expression of BGP during 'adenoma carcinoma sequence' (ACS) showed excellent correlation with the increased dysplasia and was found prior to p53 expression. Positive staining in overtly normal looking colonic mucosa (BGP foci) was observed mainly around carcinomas without any adenoma component, and frequent p53 mutation (41.2%) was detected in the BGP foci using PCR-single strand conformation polymorphism analysis. It is suggested that BGP is a novel biomarker for carcinogenesis in the intestinal-type gastric carcinoma and in both of the pathways of ACS and the 'de novo' colorectal carcinoma.     

P130Cas和PTEN信号蛋白在胃癌中的表达及相互关系

Objective  To research the contributions of p130Cas and PTEN signal molecules to the carcinogenesis of gastric carcinoma and the relationship between them. Methods  Detecting proteins of p130Cas, PTEN and PTEN mRNA of 76 cases normal gastric mucosa and 112 cases gastric carcinoma by immunohistochemistry EnVision method and molecular hybridization in situ method respectively. Detecting PTEN genetic mutation of 30 cases normal gastric mucosa, 7 cases early gastric cancer and 30 cases progressive gastric cancer by PCR-SSCP. Results  The expression of p130Cas protein of gastric carcinoma increased significantly than that of normal gastric mucosa (P < 0.05). Opposite to above, the expression of PTEN protein of gastric carcinoma group was significantly lower than that of normal gastric mucosa group (P < 0.05). The expression of PTEN mRNA of gastric carcinoma group decreased obviously than normal gastric mucosa group (P < 0.001). Only one case exon 5 and one case exon 8 of PTEN appeared gene mutation of progressive gastric carcinoma group, the difference has no significance compared with normal gastric mucosa group and early gastric cancer group. Conclusion  The signaling molecules p130Cas and PTEN play an important role in the carcinogenesis of gastric carcinoma, and p130Cas plays the part of promoter, oppositely, maybe PTEN can inhibit it. Supported by a grant from Sanitary Science and Technological Development Foundation of Shandong Province (No. 2003HW015).     

Villin蛋白的表达及其与贲门腺癌的关系

目的 探讨Villin蛋白在贲门肠化中的作用及其与贲门腺癌(GCA)发生、发展的关系.方法 采用免疫组织化学S-P法检测128例胃镜活检及手术切除的GCA及癌旁肠化组织中Villin蛋白的表达,其中贲门肠化组织25例、肠化伴不典型增生组织48例,GCA组织55例,并选取15例胃镜普查正常贲门组织作为对照.结果 Villin蛋白在正常贲门组织中无阳性表达,在贲门肠化组织中的阳性表达率为76.0%(19/25),肠化伴不典型增生组织中的阳性表达率为60.4%(29/48),GCA组织中的阳性表达率为36.4%(20/55),比较差异有统计学意义(P<0.05).Villin蛋白的表达与GCA的分化程度有关(P<0.05).结论 Villin蛋白参与了贲门组织早期肠化和GCA的发生,并在GCA的细胞分化中起重要作用.     

Mucin gene expression and cell differentiation in human normal, premalignant and malignant esophagus

Esophageal carcinoma includes squamous cell carcinoma and Barrett's adenocarcinoma. The latter usually develops from a premalignant lesion named Barrett's esophagus. MUC genes are known to be specifically expressed in the normal, premalignant and malignant epithelia of various tissues. The aim of this study was to establish the pattern of MUC gene expression in the esophageal mucosa under normal conditions, and under pathological conditions such as squamous cell carcinoma, Barrett's esophagus and adenocarcinoma. Samples of esophageal control mucosa, metaplastic and malignant tissues were obtained from 40 patients undergoing esophagectomy for squamous cell carcinoma (n = 17), or Barrett's esophagus with adenocarcinoma (n = 23). In situ hybridization and northern blot were used with probes specific for the MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, MUC6 and MUC7 genes to assess their expression in these samples. Submucosal glands of control esophageal mucosa expressed MUC5B, whereas MUC1 and MUC4 were found in both control epithelium and squamous cell carcinoma. MUC4 expression correlated with squamous cell differentiation. Barrett's adenocarcinoma exhibited various patterns of MUC gene expression, the strongest being in the well-differentiated mucinous adenocarcinomas. Barrett's metaplasia was also associated with a specific MUC gene expression pattern, since the gastric apomucin mRNAs, MUC5AC and MUC6, were expressed in gastric metaplasia, and the intestinal apomucin mRNAs, MUC3, MUC4 and mostly MUC2, in intestinal metaplasia. Residual expression of gastric apomucin mRNAs was found in intestinal metaplasia. From these results, we conclude that MUC genes can be considered reliable phenotypic markers of the esophageal cell differentiation, thus providing new insight into the development of Barrett's esophagus.     

胃粘膜结肠型化生和小肠型化生对p21、p53、EGFR、PCNA及CEA的联合表达

 目的　探讨胃粘膜的弱化生与胃癌之间的关系。方法　应用免疫组化S-P法,检测胃粘膜结肠型及小肠型化生细胞中p21、p53、EGFR、PCNA和CEA的表达,并和胃癌组织及正常胃粘膜组织进行对照。结果　p21对判断细胞的癌变倾向有帮助,而p53仅在癌组织内才有明显表达,EGFR在胃癌组有明显表达,结肠型化生与小肠型化生有显著差异,CEA及PCNA在两型肠化生中的表达无显著差异。结论　结肠型化生较小肠型化生更易发生恶性转换。