Distribution of fibronectin and laminin in early and advanced signet-ring-cell carcinomas of the stomach

HNPCC-associated synchronous early-stage signet-ring cell carcinomas of colonic origin. A comparative morphological and immunohistochemical study of an intramucosal and a submucosal example

Signet-ring cell carcinoma (SRCC) developing in the colorectum (CR) is infrequently identified at an early stage (no deeper than submucosa). Most such examples involve the submucosa. Merely 13 cases of intramucosal CR SRCC are at hand. We recently had the opportunity to study a specimen with two synchronous early-stage SRCC, developed in a 65-year-old hereditary nonpolyposis colorectal cancer male patient with a known disease-causing mutation in MLH1. A right hemicolectomy specimen comprised a 15-mm intramucosal cecal lesion, featuring zones of conventional tubular adenoma and intraepithelial SRCC as well as tumor cells multifocally permeating the lamina propria and a 12-mm submucosally expanding SRCC of the ascending colon. The intramucosal and intraepithelial as well as stromal lesional cells displayed a normal membranous expression of beta-catenin and E-cadherin; submucosally infiltrating cells featured alterations in this complex with loss of membranous expression of both proteins and a shift with nuclear accumulation of beta-catenin, suggesting a disruption of the Wingless signaling pathway taking place at the transition from the intramucosal to the submucosal level.

Clonal analysis of superficial depressed-type gastric carcinoma in humans

BACKGROUND

An important unanswered question concerning the histogenesis of superficial-type gastric carcinoma is whether it is monoclonal or multiclonal in origin. Therefore, the authors analyzed multiple areas of each cancer with a clonality assay based on trinucleotide repeat length polymorphism of the human androgen receptor gene (HUMARA) that was subject to random inactivation of X chromosomes.

METHODS

The HUMARA assay was applied to 15 gastric carcinomas, early and advanced stage, manifested in superficial, depressed lesions of various sizes and at least some signet ring cells. DNA was extracted from fresh frozen and formalin fixed tumor tissues that were microdissected from the mucosal lesions, and the HUMARA locus was amplified by polymerase chain reaction with and without prior digestion of nonmethylated DNA with Hpa II. The amplified DNA samples were loaded on polyacrylamide gels, electrophoresed, and visualized by a silver-staining method.

RESULTS

In the 15 cases examined, 9 cancers were informative (had features of the types sought in this study), and in these 9 cancers a total of 57 areas were analyzed. In 7 of the 9 cancers, the inactivated allele was common to all the informative areas of each tumor, irrespective of the macroscopic shape of the tumor or the degree of histologic heterogeneity within it. In one of the two remaining cancers, the inactivated allele of one of the areas examined was different from those in the other areas.

CONCLUSIONS

Most of the superficial depressed-type gastric carcinomas in this study were demonstrated to be of monoclonal origin. This finding supports a notion expressed previously in the literature that superficial-type carcinoma has a long natural history, and it indicates that efforts to detect gastric carcinomas in early stages to improve patients' survival should be encouraged.

Overexpression of the 67 kD laminin receptor correlates with the progression of gastric carcinoma

This retrospective study was designed to investigate the relationship between overexpression of the 67 kD laminin receptor (67LR) using immunohistochemistry, and several clinicopathological parameters including overall survival in human gastric adenocarcinoma. We stained paraffin-embedded sections of 93 resected primary gastric adenocarcinomas using a polyclonal antibody specific for the 67LR as well as monoclonal antibodies for p53 protein, epidermal growth factor receptor, proliferating cell nuclear antigen, carcinoembryonic antigen and chromagranin. The results showed statistically significant correlations between overexpression of the 67LR and types of early or advanced gastric carcinoma (p < 0.001), depth of invasion (p < 0.001), WHO histopathologic classification (p < 0.001), stage (p = 0.001), expression of p53 protein (p = 0.019), expression of epidermal growth factor receptor (p < 0.001) and proliferating cell nuclear antigen labeling index (p = 0.002). A lower proportion of signet ring cells revealed a higher percentage of overexpression of 67LR in both early (p < 0.002) and advanced (p < 0.001) gastric carcinomas. Intestinal type adenocarcinoma (according to Lauren's classification) revealed a higher percentage of overexpression of the 67LR than the diffuse type in both early (p = 0.057) and advanced (p < 0.001) gastric carcinomas. The correlations between overexpression of the 67LR and lymph node metastasis were statistically significant (p < 0.07). Although the overexpression of the 67LR tended to correlate with lower survival rates, the correlation was not statistically significant due to the limited sample size. Our data revealed that overexpression of the 67LR is correlated with the progression of gastric carcinoma. The expression of the 67LR may be important as one of the steps which determines invasiveness during the progression of cancer.

Altered expression of extracellular matrix molecules and their receptors in chronic pancreatitis and pancreatic adenocarcinoma in comparison with normal pancreas

The aim of this study was to elucidate the expression and distribution patterns of both integrins and extracellular matrix (ECM) molecules in chronic pancreatitis (CP) and pancreatic adenocarcinoma (PC) compared with normal pancreas (NP). Expression of nine alpha-subunits (alpha 2-alpha 6, alpha V, alpha L, alpha M, and alpha X), four beta-subunits (beta 1, beta 3-beta 5), and four ECM molecules (type IV collagen, laminin, fibronectin, and vitronectin) was investigated immunohistochemically. In CP, all integrins except alpha V showed nearly the same staining patterns compared with NP. Some acinar cells in CP expressed alpha V. Whereas alpha 2, alpha 3, and alpha 6 expression was stronger and diffuse, no alpha 5 expression was seen in PC. Basement membrane (BM) showed continuous staining in CP, whereas it showed discontinuous/absent staining in PC with antitype IV collagen, laminin, and vitronectin antibodies. Some carcinoma cells showed reverse correlation between alpha 2, alpha 3, and alpha 6 expression and type IV collagen and laminin expression. Fibronectin showed diffuse stromal expression in CP and PC. Some acinar cells or duct cells in CP carcinoma cells in PC showed intracellular VN expression. These results suggest that these integrins and ECM molecules are involved in inflammatory and malignant processes in pancreas.

Expression of laminin, collagen IV, fibronectin, and type IV collagenase in gastric carcinoma. An immunohistochemical study of 87 patients

BACKGROUND

This study attempted to determine if there is a pattern of matrix/matrix-degrading-enzyme immunoreactivity related to the morphologic types of gastric carcinoma or to their invasiveness.

METHODS

The authors performed an immunohistochemical study of the basement membrane antigens laminin and collagen IV, fibronectin, and Type IV collagenase in a series of 87 gastric carcinomas and their respective nodal metastases (n = 329).

RESULTS

Laminin expression was observed almost exclusively in carcinomas of the intestinal type. The expression of collagen IV was significantly higher in intestinal (52%) and atypical (44%) carcinomas than in diffuse (10%) carcinomas; collagen IV expression also was significantly correlated with lymphatic invasion and aneuploidy. Ninety percent of the carcinomas expressed fibronectin, mostly in the connective tissue at the invading edge of the tumors; fibronectin expression was significantly related to the expanding growth pattern of the neoplasms. Eighty-six percent of the tumors expressed Type IV collagenase, regardless of the histologic type or invasive properties. No relationship was observed between the expression of any of the antigens and the S-phase fraction of the tumors. No significant differences were found between the immunohistochemical profile of the primary tumors and their metastases.

CONCLUSIONS

The authors conclude that the expression of basement membrane antigens is related to the type of gastric carcinomas, rather than the cell differentiation or proliferative activity of the tumors. The putative prognostic meaning of the relationship between collagen IV immunoreactivity and aneuploidy and lymphatic invasiveness of the carcinomas remains to be clarified.

Progression of signet ring cell carcinomas in the human stomach

BACKGROUND

Stomach cancers show various growth patterns. It remains to be clarified how this variability is related to the genetic changes that occur during tumor progression.

METHODS

To estimate the genetic changes from tumor ploidy, maps were made (using DNA cytofluorometry of metaphase cells in histologic sections) of 39 advanced signet ring cell carcinomas of the human stomach and correlated with tumor stage and the size of the primary mucosal lesion.

RESULTS

Aneuploid area and multipattern aneuploidy were particularly common in advanced cancers with primary mucosal lesions smaller than 2 cm in diameter, of which a large portion were predominantly aneuploid and already diffusely infiltrating. As the tumor stage advanced, the incidence of aneuploidy in the mucosal lesion increased, whereas predominantly aneuploid tumors were less common as primary mucosal lesions became larger. Purely diploid areas with an incidence of polyploidy as low as in early cancers were common in advanced cancers. In addition, there were diploid-appearing cancer cells that infiltrated diffusely and were accompanied by polyploid as often as aneuploid cells. Some of these were aneuploid at the chromosomal level.

CONCLUSIONS

In signet ring cell carcinoma, aneuploid cells show higher invasive activity toward the extramucosal part and may occur incidentally in originally diploid tumors, depending on the degree of genetic instability. An analysis of polyploidy is useful for differentiating cytometrically diploid (but actually, aneuploid) cells from diploid cells with minor genetic abnormalities.

Morphology and modes of cell proliferation in earliest signet-ring-cell carcinomas induced in canine stomachs by N-ethyl-N'-nitro-N-nitrosoguanidine

Signet-ring-cell carcinomas were induced in the stomach of 12 beagle dogs by p.o. administration of N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG), and the morphology and modes of cell proliferation in an incipient stage of cancer growth were studied with bromodeoxyuridine (BrdUrd) incorporation. From 5 to 27 months after the completion of 8 months' carcinogen treatment, minute carcinomas were found in the stomachs of 9 dogs. Before sacrifice, the dogs were given a single or repeated i.v. injections of BrdUrd for 1-3 days. Minute signet-ring-cell carcinomas were found to form a layered structure, in which the cancer cells proliferated in the lamina propria at the gland-neck level and differentiated to postmitotic signet-ring cells at the upper and lower levels of the mucosa. From repeated injections of BrdUrd, the time required for all the proliferative cells to be labelled with BrdUrd (reflecting the maximum cell-cycle time) was estimated to be 1.7 days for the normal glands, and 2.7 days for minute signet-ring-cell carcinomas. From the labelling index with BrdUrd as well as from the morphology, earliest carcinomas were identified in the single gland. There remained atrophic normal epithelium commonly in the single-gland lesions. Proliferative atypical cells appeared to be shed into the stroma passively through the atrophy and subsequent collapse of the gland rather than through active invasion. This may be a reason why cancer cells in minute signet-ring cell carcinomas preserved the normal pattern of cell renewal movement to form the layered structure.