Ken-ichi Mukaisho

Alterations of chromosomal copy number during progression of diffuse-type gastric carcinomas: metaphase- and array-based comparative genomic hybridization analyses of multiple samples from individual tumours.

The application of comparative genomic hybridization (CGH) has led to the rapid accumulation of cytogenetic information on gastric carcinoma (GC), but there is little information on the time sequence of cytogenetic changes. In the present study, degenerate oligonucleotide‐primed polymerase chain reaction (DOP‐PCR) and CGH were applied to multiple samples microdissected from 19 diffuse‐type GCs including eight early cancers. Recurrent gains were detected at 8q, 3q, 7q, and 8p, and loss at 17p (in more than 50% of the cancers), the frequencies of which were fairly similar between the samples with (SIG) and those without (POR) abundant signet ring cells. Earlier stemline changes (8q+, 8p+, 1q+, 17p−, etc), with breakpoints that were common to all the samples, were discriminated from later sideline changes (2q+, 11q+, 17q−, 21q−, etc) in individual tumours. The changes were generally common to early and advanced cancers, except for 7p+, 15q+, 3p−, and 18q−, which were largely sideline changes and more frequently detected in advanced cancers (p < 0.05). Because the samples with 7p+ had a greater number of copy‐number changes than those without 7p+ (p < 0.01), 7p+ may play a role in tumour progression by acceleration of chromosomal instability. Fifteen different chromosomal loci with amplification were detected in ten cases, mostly as sideline changes in advanced cancers. By microarray‐based CGH, KRAS, MDM2, and FGFR2 were confirmed in the amplicons at 12p, 12q, and 10q, and FES at 15q26, for the first time in GC. These results support the notion that SIG and POR are of a genetically single lineage in both early and advanced diffuse‐type GC and that the majority of advanced cancers derive from early cancers through the accumulation of various sideline changes in addition to stemline changes. Copyright

Gastric-type well-differentiated adenocarcinoma and pyloric gland adenoma of the stomach

Since 1985, when gastric-type well-differentiated adenocarcinomas were demonstrated in hyperplastic polyps of the stomach, we have studied phenotypic expression in gastrointestinal epithelial lesions. The recent discovery of MUC genes coding core proteins of mucin has improved research on the phenotypic expression of gastrointestinal neoplasms. The disease entity of gastric-type well-differentiated adenocarcinoma has recently been accepted, especially in Japan and Europe. This entity has often become a clinicopathological subject of discussion, because its biological behavior is possibly highly malignant, in spite of the difficulty in making endoscopic and histopathological diagnoses. Even under these circumstances, the term “gastric adenoma” usually means flat adenoma of the intestinal type. Gastric-type adenomas have been regarded as exceptional until recently. Although gastric-type adenomas could theoretically be classified into foveolar type and pyloric-gland type, foveolar-type adenoma is, in practice, difficult to distinguish from gastric-foveolar-type adenocarcinoma. In 2003, we first reported systematic clinicopathological analyses of pyloric gland adenoma, demonstrating its unstable and precancerous nature. In this article, we review and discuss the clinicopathological and molecular pathological aspects of gastric-type well-differentiated adenocarcinomas and pyloric gland adenomas, mainly based on our published and unpublished data.

Long-term proton pump inhibitor administration worsens atrophic corpus gastritis and promotes adenocarcinoma development in Mongolian gerbils infected with Helicobacter pylori

Background We investigated whether corpus atrophic gastritis worsens in Mongolian gerbils (MGs) after long-term administration of proton pump inhibitor (PPI). MGs are an excellent model for studying Helicobacter pylori-related gastritis and adenocarcinoma. Methods MGs were separated into four groups (n =15/group); H pylori (ATCC43504) was inoculated into the OPZ(omeprazole)+Hp (H pylori) and Hp groups, a PPI (OPZ) was administered to the OPZ+Hp and OPZ groups and the control group received no treatment. MGs had access to food containing omeprazole (100 mg/kg body weight/day) for 6 months, after which their stomachs were removed and cut into nine sections (six sections in the fundus and three sections in the antrum). Corpus atrophy was evaluated by the absence of parietal cells in the six sections in the fundus. First, we calculated a percentage of the area devoid of parietal cells in each haematoxylin and eosin-stained section, and then we scored the degree of atrophy by adding the percentages of the six sections. A full score was 600. Results Neutrophilic and lymphoid infiltrates were greater in the OPZ+Hp group than in the other groups. The corpus atrophy score in the OPZ+Hp group was significantly higher than that in the Hp group (p<0.0048, Student t test). Significantly more adenocarcinomas were found in the OPZ+Hp (60%) than in the Hp (7%) group animals. Conclusion Long-term PPI administration promotes development of adenocarcinoma, which is associated with the progression of atrophic corpus gastritis in MGs infected with H pylori.

High animal‐fat intake changes the bile‐acid composition of bile juice and enhances the development of Barrett's esophagus and esophageal adenocarcinoma in a rat duodenal‐contents reflux model

The dietary components responsible for the development of Barretts esophagus (BE) and esophageal adenocarcinoma (EAC) remain unclear. Wistar rats were divided into four groups based on their diet: a low soybean‐oil diet, a low cow‐fat diet, a high soybean‐oil diet, and a high cow‐fat diet. First, we evaluated the bile acid composition of the bile juice in each group without operation, using high‐performance liquid chromatography. Because only high cow‐fat intake induced changes in the composition of bile acids in bile juice, we then selected animals fed with a low soybean‐oil diet and those with a high cow‐fat diet to carry out esophago‐jejunostomy for reflux of the duodenal contents, and compared sequential morphological changes between these groups up to 30 weeks after surgery. At 30 weeks after surgery, the reflux animals in the high cow‐fat group showed a significantly higher incidence of BE and Barretts dysplasia than those in the low soybean‐oil group, and the incidence of EAC in the high cow‐fat group was also slightly higher than that in the low soybean‐oil group. High dietary animal fat changed the bile‐acid composition and increased the concentration of taurine conjugates in the bile juice. These increased bile acids promoted the development of BE and Barretts dysplasia leading to EAC. (Cancer Sci 2007; 98: 1683–1688)

Cytokeratin 7/20 and mucin core protein expression in ulcerative colitis-associated colorectal neoplasms

Different histogenetic pathways have been suggested between ulcerative colitis (UC)-associated neoplasia and sporadic colorectal neoplasia. Little is known about the cytokeratin (CK) and mucin expression in UC-associated neoplasms. To clarify the characteristics of UC-associated colorectal carcinogenesis, we examined the immunohistochemical expression of CK7, CK20, MUC2, MUC5AC and MUC6 in 90 colorectal neoplasms, including 22 UC-associated adenocarcinomas (colitic cancer; CC), ten high-grade dysplasias (HGD) in UC, nine low-grade dysplasias (LGD) in UC, 24 sporadic tubular adenomas (TA) and 25 adenocarcinomas (AC). CK7 was positive in most of UC-associated neoplasms: 59% of CC cases, 80% of HGD and 89% of LGD, respectively, whereas, in non-UC associated neoplasia, 21% of TA and 12% of AC. The frequency of MUC6 expression in UC-associated neoplasia was 32% in CC, 30% in HGD and 44% in LGD, respectively, whereas, in non-UC associated neoplasia, 4.2% in TA and 0% in AC. MUC5AC expression in UC-associated neoplasia was detectable in 73% of CC, 90% of HGD and 89% of LGD, respectively; in non-UC associated neoplasia 67% in AC and 20% in TA. There were obvious differences in the expression of CK7 and MUC6 between UC-associated neoplasms and sporadic tumors. The incidence of MUC5AC expression in UC-associated neoplasms was also higher than sporadic tumors. These results suggest that gastric-type mucins play an important role in the initial step of CC-tumorigenesis, and CK7 and gastric-type mucins may be useful in the differential diagnosis between UC-associated neoplasms and sporadic ones.

Expression of Cdx2 in Early GRCL of Barrett’s Esophagus Induced in Rats by Duodenal Reflux

The intestine-specific caudal-related homeobox transcription factor Cdx2 is widely accepted to play a key role in intestinal development and differentiation in mammals. We studied the role of Cdx2 in the development of Barrett’s esophagus (BE). In previous studies, we have shown a sequence of morphological changes of squamous epithelium leading to BE, found a peculiar metaplastic change common to other parts of gut, and proposed the concept of a “gut regenerative cell lineage” (GRCL). The GRCL is characterized by pyloric–foveolar metaplasia with goblet cell metaplasia, which occurs in the regenerative process in response to chronic inflammation. BE very likely develops through the GRCL, and we studied the expression of Cdx2 in various lesions of rat esophageal mucosa induced by duodenal reflux, using reverse transciptase–polymerase chain reaction and immunohistochemistry against Cdx2. We found that Cdx2 was expressed not only in specialized columnar epithelium (SCE) of BE, but also in several pyloric gland and foveolar metaplastic cells which developed in the basal layer of the squamous epithelium at an earlier stage of SCE development. These findings indicate that Cdx2 plays a crucial role in directing intestinal-type differentiation of the GRCL.

CD10 expression is useful in the diagnosis of follicular carcinoma and follicular variant of papillary thyroid carcinoma.

CD10/neutral endopeptidase 24.11(NEP) is a membrane-bound zinc metalloproteinase the expression of which represents a useful tool in the classification and diagnosis of malignant leukemia and lymphoma. Recently, CD10 has been found to be expressed in nonhematopoietic tissues and various types of neoplasms. In this study, we examined CD10 immunostaining in paraffin sections of 70 distinct lesions to investigate whether CD10 is a useful diagnostic marker for thyroid neoplasms. CD10 was not detected in normal thyroid tissue, benign lesions (15 follicular lesions and 15 adenomatous goiters), and pure papillary carcinomas except for follicular variants. In contrast, CD10 was expressed in 8 of 10 (80%) follicular carcinomas and 7 of 9 (77%) follicular variant of papillary thyroid carcinomas. This appears to be the first report on the expression of this member of a newly identified gene family in thyroid tumors. In conclusion, immunohistochemistry of CD10 in paraffin sections is valuable in the classification of thyroid follicular lesions into benign and malignant groups and in the diagnosis of follicular variant of papillary thyroid carcinoma.

Immunohistochemical analysis of pyloric gland adenomas using a series of Mucin 2, Mucin 5AC, Mucin 6, CD10, Ki67 and p53

A pyloric gland adenoma (PGA) of the stomach was first described in a book chapter in 1976 by Kurt Elster and has been rarely reported in the literature. We expanded the current immunohistochemical data of these adenomas in a detailed series to further analyse the immunhistochemical status of PGA. From 60 patients with PGA with and without adenocarcinomas of the gastrointestinal tract, an immunhistochemical panel of Mucin 2, Mucin 5AC, Mucin 6, CD10, Ki67 and p53 was used to define the expression of these markers. All PGA were positive for Mucin 6 (deep mucoid glands), which they express over the whole lesion up to the surface. Mucin 5AC expression varies from case to case. A transition from gastric to intestinal differentiation can be observed focally as depicted by Mucin 2 and CD10 in 65% of the cases. The gastric corpus mucosa of elderly patients with either Helicobacter pylori gastritis or autoimmune gastritis is highly affected. Almost 47% of all PGA already underwent malignant transformation into adenocarcinoma. Significant immunohistochemical differences could be detected between PGA with and without adenocarcinoma regarding ki67 and p53. The diagnosis of PGA can be confirmed immunohistochemically by staining against apomucin 6 and apomucin 5AC. Focal intestinal differentiation supports the hypothesis that gastric adenocarcinomas can initially develop from carcinomas of the gastric type and transform into intestinal type later on. The high frequency of malignant transformation of PGA underlines its high potential for invasive malignancy.

Pyloric gland adenoma arising in Barrett’s esophagus with mucin immunohistochemical and molecular cytogenetic evaluation

Pyloric gland adenoma is a recently described and very rare entity. The occurrence of adenoma is very unusual in Barrett’s epithelium of the esophagus. We report a case of esophageal polyp showing the features of pyloric gland adenoma, which was surrounded by so-called specialized columnar epithelium. Immunohistochemically, most tumor glands were strongly positive for MUC6, except in the superficial layer. MUC5AC was positive in almost all tumor cells, but MUC2 and CD10 were negative in the tumor. MIB-1-positive proliferating cells were distributed throughout the tumor. Microdissection and comparative genomic hybridization analyses revealed losses on 2p24–25.2, 2q14.1-ter, 5q31.3–32, 6q23–24, 8q23–24.2, 11q22.3–24 and 18q21.1–22. This is the first case of pyloric gland adenoma found to arise in Barrett’s epithelium of the esophagus, showing its unstable and precancerous nature.

Gastric carcinogenesis by duodenal reflux through gut regenerative cell lineage.

To elucidate the histogenesis of gastric stump cancer, we performed an operation in rats to make all duodenal contents flow back into the glandular stomach. The subjects were 41 rats, and sequential morphological changes of the duodenogastric stoma and the incidence of stump cancers were studied. Serial sections around the stoma were studied with mucin stains such as paradoxical concanavalin A (Con A), galactose oxidase Schiff (GOS), and high-iron diamine–Alcian blue (HID-AB). An immunohistochemical study on cell proliferation with bromodeoxyuridine (BrdU) was also done. At week 30, pyloric gland type cells positive for Con A first appeared at the base of the intestinal crypts and the fundic glands adjacent to the anastomosis. These glands became large with time, resulting in formation of cystically dilated glands. These gland cells were partially stained with GOS, and then they retained a proliferative activity. These changes seemed to resemble “gastritis cystica profunda” in human remnant stomachs. At 50 and 80 weeks, adenocarcinomas were observed in 4 of 10 rats (40.0%) and in 16 of 21 rats (76.2%), respectively. We have noted that the early change of cystic proliferation of mucous glands resembled the so-called “ulcer associated cell lineage (UACL)” described by others, but our characteristic finding was not only pyloric but also foveolar metaplasia. This pyloric–foveolar metaplasia subsequently led to development of glands with intestinal-type goblet cells, which looked like incomplete intestinal metaplasia. This sequence was different from UACL, and very recently, we proposed a concept of “gut regenerative cell lineage (GRCL)semi; from pyloric–foveolar to with goblet cell metaplasia in regeneration,” common to all parts of the gut, and the stump cancer appeared to arise from GRCL.