Gastric and intestinal phenotypic expression of human stomach cancers as revealed by pepsinogen immunohistochemistry and mucin histochemistry

Gastric and intestinal phenotypic expression in 223 surgically obtained primary gastric cancers and their histogenetic relationship to intestinal metaplasia in the surrounding gastric mucosa were studied by mucin histochemistry and pepsinogen (Pg) immunohistochemistry. Histochemical differentiation of mucins (paradoxical concanavalin A, the galactose oxidase-Schiff sequence and sialidase-galactose oxidase-Schiff) and immunohistochemical staining of Pgs I and II, allowed differentiation of gastric cancer cells from different histological categories into gastric elements including mucous neck cells, pyloric gland cells and surface mucous cells or intestinal elements including goblet cell and intestinal absorptive cell types. Of 122 papillary and tubular adenocarcinomas, 33 (27.1%) consisted mainly of gastric-type cells and 42 (34.4%) predominantly of intestinal-type cells. The remainder (38.5%) consisted of mixtures of gastric- and intestinal-type cells. Of 101 poorly differentiated adenocarcinomas, signet ring cell carcinomas and mucinous adenocarcinomas, 59 (58.4%) consisted mainly of gastric-type cells and 20 (19.8%) mainly of intestinal-type cells. Seven out of 35 papillary and tubular adenocarcinomas consisting mainly of gastric-type cancer cells were surrounded by mucosa with intestinal metaplasia. Conversely, 10 out of 40 papillary and tubular adenocarcinomas consisting mainly of intestinal-type cancer cells were observed in nonmetaplastic gastric mucosa. Thus no relationship as regards intestinal phenotypic expression was found between gastric cancers and surrounding gastric mucosa.     

Gastric and Intestinal Phenotypic Expression of Human Stomach Cancers as Revealed by Pepsinogen lmmunohistochemistry and Mucin Histochemistry

Gastric and intestinal phenotypic expression in 223 surgically obtained primary gastric cancers and their histogenetic relationship to intestinal metaplasia in the surrounding gastric mucosa were studied by mucin histochemistry and pepsinogen (Pg) immunohistochemistry. Histochemical differentiation of mucins (paradoxical concanavalin A, the galactose oxidase-Schiff sequence and sialidase galactose oxidase Schiff) and immunohisto chemical staining of Pgs I and II, allowed differentiation of gastric cancer cells from different histological categories into gastric elements including mucous neck cells, pyloric gland cells and surface mucous cells or intestinal elements including goblet cell and intestinal absorptive cell types. Of 122 papillary and tubular adenocarcinomas, 33 (27.1%) consisted mainly of gastric type cells and 42 (34.4%) predominantly of intestinal type cells. The remainder (38.5%) consisted of mixtures of gastric- and intestinal-type cells. Of 101 poorly differentiated adenocarcinomas, signet ring cell carcinomas and mucinous adenocarcinomas, 59 (58.4%) consisted mainly of gastric-type cells and 20 (19.8%) mainly of intestinal-type cells. Seven out of 35 papillary and tubular adenocarcinomas consisting mainly of gastric type cancer cells were surrounded by mucosa with intestinal metaplasia. Conversely, 10 out of 40 papillary and tubular adenocarcinomas consisting mainly of intestinal-type cancer cells were observed in non metaplastic gastric mucosa. Thus no relationship as regards intestinal phenotypic expression was found between gastric cancers and surrounding gastric mucosa.     

Gastric or intestinal phenotypic expression in the carcinomas and background mucosa of multiple early gastric carcinomas

AIMS: The differences in phenotypic expression between multiple early gastric carcinomas (EGCs) and solitary EGCs were evaluated in this study. METHODS AND RESULTS: Fifty-three cases (53 lesions) of solitary EGCs and 50 cases (112 lesions) of multiple EGCs were studied. According to the classification of intestinal metaplasia, the phenotypes of carcinomas and background mucosa were classified into four categories-complete intestinal type, incomplete intestinal type, gastric type and unclassified type-based on the combination of expression of CD10 (small intestinal brush border), MUC2 (intestinal goblet cell), HGM (gastric foveolar epithelium) and Con A (gastric pyloric glands). The incidence of gastric-type carcinomas (48%) and the incidence of incomplete intestinal-type background mucosa (75%) among the multiple EGCs was higher than among the solitary EGCs. There was a significant difference in distribution of phenotypic expression of carcinomas and background mucosa between the solitary EGCs and the multiple EGCs, the latter being associated with incomplete intestinal metaplasia. CONCLUSIONS: Both the carcinomas and the background mucosa of multiple EGCs have an unstable status, since they more commonly possess the hybrid phenotype of the stomach and the small intestine than does solitary EGC. Such instability is considered to contribute to a high neoplastic potential and the multiple occurrence of carcinomas.     

Well-differentiated adenocarcinoma mimicking complete-type intestinal metaplasia in the stomach.

We describe extremely well-differentiated intestinal-type adenocarcinomas of the stomach which mimic complete-type intestinal metaplasia. It is often difficult to discriminate such neoplastic lesions from inflamed or regenerative changes of intestinal metaplasia histologically. The aim of this study was to elucidate the clinicopathologic features of this unique carcinoma. Eight cases of gastric carcinoma of this type that were invasive beyond the muscularis mucosae were selected for mucin histochemical and immunohistochemical analyses. The carcinomas showed the following features: (1) predominant cells that had differentiated to mature neoplastic cells, with features of small intestinal absorptive cells (complete-type intestinal metaplastic cells), which have sialomucin, MUC2-positive cells, and brush border features detected by CD10 (56C6) staining; (2) neoplastic tubules in the mucosa showing branching, tortuous, anastomosing, and plexiform structures, which were more pathognomonic than the cytological features; (3) lesions distributed predominantly in the middle third of the stomach and surrounded by the fundic mucosa; and (4) zonal distribution of Ki-67-positive proliferative cells like those of intestinal metaplasia in the lower third to half of the cancerous tubules in the mucosa. The lesions consisted mainly of illusory carcinoma; however, there were foci of pathognomonic elements in some areas of the tumors. Several biopsy samplings of the lesion would ensure the histopathologic diagnosis. This unique lesion forms a subgroup of intestinal-type carcinomas of the stomach and is suggested to have a close link with complete-type intestinal metaplasia, previously ignored as a precancerous lesion.     

Das gastral differenzierte Magenadenokarzinom

Gastric carcinomas are classified histogenetically into diffuse and differentiated types. The latter are often referred to as intestinal-type carcinomas and are believed to originate from intestinal metaplasia. However, histogenetic studies on smaller and initial lesions of the differentiated adenocarcinoma do not support this. From phenotypical expressions of neoplastic lesions arising in hyperplastic polyps of the stomach we first proposed an entity of gastric-type adenocarcinomas, which has been widely accepted. Our recent mucin and immunohistochemical investigations reveal that most smaller adenocarcinomas retain gastric-type differentiation and that those of the exclusively intestinal phenotype are rather rare. On the other hand, most adenomas are strongly and extensively positive for intestinal marker, indicating that the adenoma-carcinoma sequence is not a common event in the stomach carcinogenesis. Other studies show that the expression of intestinal mucin or carbohydrate antigen as expressed in intestinal metaplasia is manifested more extensively in carcinoma cells in larger tumors. It is suggested that intestinalization of tumor cells is a time-dependent phenomenon. Differential gene abnormalities between gastric- and intestinal-type carcinomas of the stomach are discussed, regarding their histogenesis and progression.     

Gastric adenomas and superficial adenocarcinomas display distinct patterns of mucin carbohydrate and core protein expression

AIMS: To investigate the histogenetic relationship between gastric epithelial neoplasms we studied differences in expression of mucin carbohydrate antigens and mucin core protein, in normal and metaplastic gastric mucosa, and in gastric adenomas and superficial adenocarcinomas. METHODS AND RESULTS: We generated four monoclonal antibodies, including HGM72/75 against human gastric mucin and HCM14/21 against human colonic mucin, and investigated immunoreactivities of these antibodies and MUC2 protein expression in normal and metaplastic gastric mucosa, adenomas (15 samples) and superficial adenocarcinomas (intestinal-type, 77; diffuse-type, 59 samples). HGM72 reacted with mucous neck cells of the fundic glands and with pyloric glandular cells whereas HGM75 stained foveolar cells and metaplastic goblet cells. Weak binding of HCM14/21 and strong staining with MUC2 were found in metaplastic goblet cells. Binding of HGM75, HCM14, MUC2, but not HGM72 was high in adenomas. An equivalent staining with HGM72 and HGM75 with low expression of MUC2 and HCM14 was shown in intestinal-type carcinomas while the diffuse-type demonstrated more strong reactivity with HGM75 than with HGM72, MUC2 and HCM14. Little binding of HCM21 was observed in any specimens. CONCLUSIONS: This study demonstrates that adenomas predominantly have a intestinal phenotype, but both types of adenocarcinomas retain some cells with a gastric phenotype during the early steps of neoplastic development.     

Hepatocyte expressions in hepatocellular carcinomas, gastrointestinal neoplasms, and non-neoplastic gastrointestinal mucosa: its role as a diagnostic marker

We performed immunohistochemical staining against Hepatocyte (Hep) and CD10 antibodies in 75 hepatocellular carcinoma (HCC), 50 cholangiocarcinomas, 49 colorectal adenocarcinomas, and 308 gastric adenocarcinomas by tissue array method. We also evaluated the various non-neoplastic adult tissues and fetal digestive organs. Hep was expressed in 80% of HCCs, and HCCs without Hep expression were more likely to have a higher Edmondson & Steiner grade than HCCs with Hep expression (p=0.004). In non-HCCs, 16% of cholangiocarcinomas, 8.2% of colorectal carcinomas, and 44.2% of gastric carcinomas expressed Hep. Gastric carcinomas with Hep expression were significantly associated with early gastric carcinomas (p<0.001). In non-neoplastic tissues, Hep was found expressed in normal hepatocytes, small intestinal mucosa, and intestinal metaplasia of the stomach. Fetal hepatocytes expressed Hep after 19 weeks of gestation. CD10 was detected in 46.7% (35/75) of HCCs, and canalicular staining pattern was predominant in HCCs. In conclusion, the expression of Hep and CD10 may help to distinguish HCCs from non-HCCs.     

AMACR/P504S在胃黏膜高度异型增生诊断中的价值

目的观察AMACR/P504S在正常胃黏膜、不确定性异型增生、低度异型增生、高度异型增生和胃肠型腺癌中的表达,探讨其在胃黏膜高度异型增生诊断中的价值。方法应用免疫组化EnVision法检测20例无异型增生、30例不确定性异型增生、25例低度异型增生、30例高度异型增生和20例肠型腺癌中AMACR/P504S的表达。结果 AMACR/P504S在无异型增生和不确定性异型增生的胃黏膜中均为阴性表达,在低度异型增生中AMACR/P504S阳性率为4.0%,高度异型增生和肠型腺癌中阳性率分别为73.3%和55%,AMACR/P504S在高度异型增生中的表达明显高于低度异型增生(P<0.01),与肠型腺癌无差异(P>0.05)。AMACR/P504S对高度异型增生诊断的特异性为98.7%,敏感性为73.3%。结论 AMACR/P504S可作为胃黏膜高度异型增生与低度异型增生和不确定性异型增生鉴别诊断的免疫标记物。     

The expression of Lewis antigens in neoplasms of the gastrointestinal tract

The indirect immunoperoxidase technique has been used to demonstrate Lea and Leb antigens in paraffin sections of both morphologically normal gastric and colonic mucosae and their neoplastic counterparts. Expression differed in various regions of the gastrointestinal tract: Leb occurred most frequently in the stomach and Lea most frequently in the colon. Coexpression of Lea and Leb occurred in only 5% of cases of normal mucosa, in 65% of gastric carcinomas and in 82% of carcinomas of the colon. Furthermore, 75% of cases of intestinal metaplasia in gastric mucosa and 30% of tubular adenomas, 50% of villous adenomas and 70% of tubulovillous adenomas in the colon co-expressed Lea and Leb antigens. In this study, the expression of Lewis antigens in carcinoma was found to differ from that of adjacent normal mucosa in 95% of cases of gastric carcinoma and 100% of cases of colonic carcinoma. The differences were shown by antigen acquisition and/or deletion. Similar changes were shown in 88% of cases of intestinal metaplasia in gastric mucosa, 20% of cases of tubular adenomas and 57% of cases of villous and tubulovillous adenomas of colon.     

Liver-type fatty acid-binding protein is highly expressed in intestinal metaplasia and in a subset of carcinomas of the stomach without association with the fatty acid synthase status in the carcinoma.

OBJECTIVE: To investigate the relation of liver-type fatty-acid-binding protein (L-FABP) expression to the clinicopathological characteristics or the fatty acid synthase status of gastric cancers. METHODS: L-FABP expression was examined immunohistochemically in 667 gastric cancers, 60 gastric adenomas, and non-neoplastic epithelium contiguous with cancer tissue including normal foveolae, intestinal metaplasia, regenerative epithelium, and gastric glands. RESULTS: L-FABP was positive in 38% (high in 9% and low in 29%) of gastric cancers. It occurred preferentially in papillary carcinomas, female cases, and in patients under 50 years. In gastric cancers, L-FABP expression had no intimate correlation with the FAS status, and it showed no relationship with prognosis and cancer progression as indicated by venous and lymphatic permeation, and nodal or hepatic metastasis. Gastric tubular adenomas mainly revealed low (22%) expression of L-FABP while intestinal metaplasia showed the most frequent (>95%) and intense L-FABP expression. Normal foveolae and gastric glands showed no or less L-FABP expression. CONCLUSIONS: L-FABP is highly and intensely expressed in metaplasia and in a subset of gastric adenocarcinomas, without association with progression, prognosis and fatty acid synthase status of the carcinoma.     

Cancerous and non-neoplastic stem cells in the stomach similarly express CD44 and CD133

CD44 and CD133 have been considered as cancer stem cell (CSC) markers. Stem cell markers are rarely described in healthy stomach tissues. However, the clinicopathological and prognostic value of CD44 and CD133 in gastric cancer remains controversial. This study investigated the expression of CD44 and CD133 in gastric cancer and non-neoplastic gastric mucosa. We used samples of primary gastric adenocarcinomas (n = 69), metastatic lymph nodes (n = 30), intestinal metaplasia (n = 17), and histologically normal gastric tissues of surgical margins (n = 54). The expression of CD44 and CD133 were studied in samples by immunohistochemistry. Fisher’s exact test and a logistic regression model were used in this study. CD44 expression was observed in 12% of samples with intestinal metaplasia, 20% with lymph node metastases, 22% with normal mucosa, to 30% of samples with primary tumors. Most of these positive tumors showed immunostaining in less than 4% of cancerous cells, mainly in the diffuse type. CD133 expression was observed in 7% (intestinal metaplasia) to 46% (normal mucosa). In the positive cases of cancer (24%), in most of them, less than 3% of cells were marked. CD44 and CD133 expression in the histologically normal gastric mucosa was restricted to the deeper regions of the gastric crypts at the level where stem cells and progenitor cells are usually found. CD44 and CD133 expression occurs in few gastric cancer cells, mainly in diffuse carcinomas, and are expressed in histologically normal gastric mucosae. None of the markers are specific for cancer and are also present in intestinal metaplasia and the normal mucosa.     

Expression of alpha-methylacyl-CoA racemase (P504s) in various malignant neoplasms and normal tissues: astudy of 761 cases

Alpha-methylacyl CoA racemase (AMACR), also known as P504S, plays an important role in peroxisomal beta-oxidation of branched-chain fatty acids. It has recently been shown that AMACR is highly expressed in prostate cancer and that it may be an important diagnostic marker for prostate carcinoma. However, little is known about expression of AMACR in normal tissues and other malignant tumors. In this study, we investigated expression of AMACR in 539 malignant tumors and 222 normal human tissues of various types by immunohistochemical analysis. mRNA levels of AMACR in normal organs and in selected tumors were assessed by real time PCR. In normal tissue, high expression of AMACR mRNA was identified in liver, kidney and salivary gland, while AMACR protein was detected in liver (hepatocytes), kidney (tubular epithelial cells), lung (only bronchial epithelial cells), and gallbladder (only mucosal epithelial cells). High expression of AMACR mRNA was found in prostate, liver, and kidney cancers but rarely in stomach and bladder cancers. A high percent of adenocarcinomas arising from these organs express AMACR, including 17 of 21 (81%) of hepatocellular carcinomas and 18 of 24 (75%) of renal cell carcinomas. In addition, carcinomas arising from tissues normally not expressing AMACR were also positive for the antigen, including 17 of 18 (94%) prostate carcinomas, 9 of 29 (31%) of urothelial carcinomas, and 4 of 15 (27%) of gastric adenocarcinomas. Two hundred and fifty cases of adenocarcinomas from lung, breast, pancreas, bile duct, adrenal gland, salivary gland, ovary, thyroid and endometrium were negative or rarely positive for AMACR. Neuroendocrine carcinomas rarely expressed AMACR. Melanomas, squamous cell carcinomas, basal cell carcinomas, soft tissue tumors (including epithelioid sarcomas and synovial sarcoma), thymomas, and germ cell tumors were negative for AMACR. Our data provide important baseline information for using AMACR in clinical practice and also are valuable in furthering understanding of the pathogenic role of AMACR in malignant neoplasms.     

Helicobacter pylori-induced changes in the gastric mucosa are associated with mitogen-activated protein kinase (MAPK) activation.

BACKGROUND: Gastric cancers are usually associated with and preceded by Helicobacter pylori (HP) infection, gastric atrophy, intestinal metaplasia, and dysplasia. HP infection alters cell kinetics of the gastric mucosa. Both proliferation and apoptosis are increased. Proinflammatory cytokines are responsible for some of these alterations. The mitogen-activated protein kinase (MAPK) signaling pathway has been implicated as a causative factor in these alterations based on in vitro studies. In this study, we investigated the effects of HP infection on gastric mucosal proliferation, apoptotic mechanisms, and the activation status of the MAPK signaling pathway at various stages of gastric carcinogenesis, especially intestinal metaplasia and dysplasia caused by HP infection. DESIGN: Stomach biopsies representing normal (n=20), HP+ (n=25), HP+ with intestinal metaplasia (n=25), HP+ with dysplasia (n=15) and gastric adenocarcinoma (n=30; 20 HP+ and 10 HP-) cases were selected. Cell proliferation was assessed by proliferating cell nuclear antigen immunostaining. Apoptosis and survival-related markers; cleaved caspase-3, and phospho-MAPK extracellular signal-regulated kinase (ERK) were detected by immunohistochemical methods. RESULTS: Proliferation index (proliferating cell nuclear antigen) and cleaved caspase-3 expression were higher in the HP+, HP+ with intestinal metaplasia, and HP+ with dysplasia groups than in normal controls (P<0.05). Cleaved caspase-3 activity was also high in the adenocarcinomas. Phospho-MAPK(ERK) expression was increased in the HP+, HP+ with intestinal metaplasia, HP+ with dysplasia and adenocarcinomas compared with the normal control group. Whereas HP- gastric carcinomas had a lower expression of phospho-MAPK. CONCLUSIONS: HP infection increases the proliferative rate of gastric foveolar cells in conjunction with an increased apoptotic rate and activation of MAPK(ERK). MAPK activation seems to be a significant and persistent event in the HP-induced neoplastic transformation.     

Altered microsatellites in incomplete-type intestinal metaplasia adjacent to primary gastric cancers.

AIM: To investigate the presence of genetic instability in precancerous lesions of the stomach. METHODS: Fifteen cases of sporadic gastric cancers with a background of intestinal metaplasia were studied by microsatellite assay at nine loci. Altered metaplastic mucosa was microdissected, reconstructed topographically, and examined immunohistochemically with an anti-p53 antibody, comparing its positive area with foci of microsatellite instability in each individual. RESULTS: Alterations at one or more loci were observed in seven of 15 cancers (46.7%) and four of 15 intestinal metaplasias (26.7%). Two cases of replication error positive phenotype had no microsatellite alterations in their metaplastic mucosa. All the microsatellite alterations in the metaplastic mucosa were restricted to incomplete-type intestinal metaplasia around the respective cancers. Moreover, in one case, an identical pattern of microsatellite alteration was detected in the cancer tissue and in the adjacent metaplastic mucosa, suggesting the sequential development of gastric cancer from intestinal metaplasia. Frequent alteration was found at the locus D1S191 (1q), indicating that this locus might be altered early in the development of intestinal-type gastric cancer. No significant association between microsatellite instability and p53 immunoreactivity was observed in the cases examined. CONCLUSION: These results indicate that microsatellite instability may be an early event in stomach carcinogenesis, especially in intestinal-type cancers.     

Expression and localization of Reg IV in human neoplastic and non-neoplastic tissues: Reg IV expression is associated with intestinal and neuroendocrine differentiation in gastric adenocarcinoma

Regenerating islet-derived family, member 4 (Reg IV) is a candidate marker for cancer and inflammatory bowel disease. In the present study, immunohistochemical analysis of Reg IV was performed in various human neoplastic (n = 289) and non-neoplastic tissues. In the stomach, foveolar epithelium was negative for Reg IV, whereas goblet cells of intestinal metaplasia and neuroendocrine cells at the base of intestinal metaplasia expressed Reg IV. Neuroendocrine cells of the small intestine and colon showed strong expression of Reg IV, whereas goblet cells of the small intestine and colon showed weak or no expression of Reg IV. Insulin-producing beta cells of the endocrine pancreas were positive for Reg IV. Among 143 gastric adenocarcinomas, Reg IV expression was detected in 42 (29.4%) and was associated with both the intestinal mucin phenotype and neuroendocrine differentiation. No association was found between Reg IV expression and clinical characteristics such as tumour stage and patient prognosis. Of 36 colorectal adenocarcinomas, 13 (36.1%) were positive for Reg IV, which was associated with tumour stage (p = 0.0379, Fisher's exact test). Expression of Reg IV was detected in 14 (93.3%) of 15 colorectal carcinoid tumours. Reg IV expression was also detected in 5 (21.7%) of 23 ductal adenocarcinomas of the pancreas. In contrast, lung cancers (n = 30) and breast cancers (n = 30) did not express Reg IV. This is the first immunohistochemical analysis of the expression and distribution of Reg IV protein in human tumours. These data suggest that Reg IV is expressed by gastrointestinal and pancreatic tumours, including adenocarcinomas and carcinoid tumours, and that Reg IV is associated with intestinal and neuroendocrine differentiation of the stomach and gastric carcinoma.     

Transforming growth factor α expression in normal gastric mucosa, intestinal metaplasia, dysplasia and gastric carcinoma—an immunohistochemical study

Using a monoclonal antibody (GF10) and a standard immunohistochemical technique, immuno-expression of transforming growth factor alpha (TGF-alpha) was found consistently within the differentiated compartment of normal adult human gastric mucosa. In 70% of mucosal samples exhibiting intestinal metaplasia there was more or less uniform TGF-alpha immunoreactivity throughout the intestinalized mucosa. Similarly, 60% of cases of dysplasia and 60% of gastric carcinomas showed strong immunoreactivity in most of the cells. However, whereas 93% of intestinal-type cancers showed strong immunoreactivity only 30% of the diffuse type were stained and then only weakly. Transforming growth factor alpha expression is thus a fairly regular feature of several types of differentiated gastric epithelia (normal, metaplastic, dysplastic and intestinal-type carcinoma), while its relative absence may be a factor in the histogenesis of the diffuse type of gastric carcinoma.     

Abundant expression of AMACR in many distinct tumour types

AIMS: Alpha-methylacyl-CoA racemase (AMACR), a mitochondrial and peroxisomal enzyme, is a valuable tool to confirm the diagnosis of prostate cancer, especially if combined with basal cell markers. To extend this diagnostic utility to other neoplasias, we comprehensively surveyed AMACR expression in human tumours. METHODS: We performed immunohistochemical analyses on tissue microarrays of AMACR expression in over 125 different human tumour types and 80 normal tissues. RESULTS: Microarray analysis revealed that tumours with prominent AMACR expression included adenocarcinomas of the prostate (72%), hepatocellular carcinomas (77%), papillary renal cell carcinomas (70%), and colorectal adenocarcinomas (71%). AMACR expression was equally frequent in colorectal adenomas and carcinomas. No significant difference in AMACR expression between untreated and hormone-refractory prostate cancers was observed. In the thyroid, AMACR expression was found in 42% of the follicular carcinomas but in only 16% of follicular adenomas. However, a more detailed analysis on a thyroid tissue microarray did not confirm a significant difference of AMACR expression in follicular adenoma and carcinomas. CONCLUSION: Taken together, the results indicate that AMACR is expressed in a wide variety of adenocarcinomas, and its diagnostic utility is restricted to specific areas.