Shinichi Murao

Altered carbohydrate composition in colorectal adenomas and carcinomas: Histochemical characterization of N-acetylgalactosamine,l-fucose, and o-acetylated sialic acid

Changes of surface sugar residues in the large intestinal mucosa may be associated with malignant transformation and may be of importance in differentiating borderline lesions. To compare these changes in normal mucosa, adenomas, and carcinomas of the large intestine, we investigated modifications of carbohydrate composition, such as those of N-acetyl-galactosamine (GalNac),l-fucose, ando-acetylated sialic acid, by histochemical staining withDolichos biflorus agglutinin (DBA) andUlex europaeus agglutinin-1 (UEA-1) lectins, and with Cullings periodic acid-thionin Schiff/potassium hydroxide/periodic acid-Schiff (PAT/KOH/PAS), respectively. For stable staining, the sections stained with DBA and UEA-1 were pretreated with potassium hydroxide and neuraminidase. We conclude that the pattern of the two lectin stainings in carcinomas is quite different from that in normal mucosa and adenomas, and that it shows the carcinomatous features in some cases of adenoma with severe atypia (borderline lesions). In contrast, PAT/KOH/PAS staining demonstrates differences between normal mucosa and adenomas rather than differences between adenomas and carcinomas.

Incidence of p53 and Ha‐ras gene mutations in chemically induced rat mammary carcinomas

To determine whether p53 alterations, which are frequent in human breast cancers, are also common in rat mammary tumors, we examined 40 tumors from 24 rats treated with 7,12‐dimethylbenz[a]anthracene (DMBA) and 34 tumors from 14 rats treated with N‐nitroso‐N‐methylurea (NMU) (an N‐nitroso compound). DMBA and NMU are known genotoxic mutagens. The entire coding regions of the p53 and Ha‐ras genes were examined for mutations by polymerase chain reaction single‐strand conformational polymorphism analysis and by direct sequencing. One of the 40 DMBA‐induced mammary tumors had a p53 mutation, a single‐base substitution (???AGC→???GGC) at codon 307, resulting in an amino‐acid change from Ser to Gly. No mutations were found in NMU‐induced tumors. The incidence of Ha‐ras gene mutation was 79% (27 of 34) at codon 12 in the NMU group and 23% (nine of 40) at codon 61 in the DMBA group. Thus, p53 mutation, in contrast to Ha‐ras mutation, did not seem to be a prerequisite for carcinogenesis in chemically induced rat mammary tumors.

Modulation of S‐100 genes response to growth conditions in human epithelial tumor cells

Many new members of the S‐100 genes are known to be associated with cell differentiation, malignant transformation, and cell cycle. Of the S‐100 genes examined In the present study, calcyclin, calpactin I light chain and calvasculln were expressed In most human epithellal tumor cells, and their expression levels differed according to various growth conditions. Their transcribed levels differed depending on each cell line, but their expression patterns were similarly changed under growth‐modulatory conditions. Their messenger RNA levels increased parallel to the S phase population of cells, and decreased at G1/G2 phases. In contrast, this expression diminished in tumor cells under growth‐Inhibitory conditions, such as treatment with topolsomerase II inhibitor VP‐16 or phorbol 12‐myristate 13‐acetate.

Allelic Loss of Chromosome 16q in Endometrial Cancer: Correlation with Poor Prognosis of Patients and Less Differentiated Histology

Deletion of certain chromosomal regions can be demonstrated in malignant cells. Chromosome 16q is one of the regions where allelic loss is frequently detected in carcinoma of the breast and many other tumors, suggesting that gene(s) which retard tumor growth may exist here. To elucidate the clinico‐pathological significance of chromosome 16q, loss of heterozygosity (LOH) was investigated using microsatellite polymorphism analysis in 58 patients with endometrial lesions (50 with endometrial carcinoma and 8 who had hyperplasia with or without atypia). When 11 regions of chromosome 16q were examined, LOH was found in 20 patients with carcinoma (40%) and none of the patients with hyperplasia. The tumors of 9 of the 20 patients (45%) showed total loss of 16q, while the others (55%) showed partial deletion. Tumors with LOH were histologically less differentiated than those without LOH (P=0.038, χ2 test). Patients with tumors showing LOH of 16q had a worse prognosis than those without LOH according to Kaplan‐Meier survival analysis (P=0.0158, log‐rank test). In addition, LOH of 16q showed a significant relationship to prognosis by Cox regression analysis. Deletion mapping of 16q demonstrated that two regions (16q22.1 and 16q22.2‐23.1) were frequently involved. Patients with 16q22.1 LOH had a poorer prognosis than those with intact 16q22.1 (P=0.0003, log‐rank test). These findings suggest that gene(s) of which defect is possibly related to the aggressiveness of endometrial cancer are localized on a limited region of 16q that includes 16q22.1.

Immunohistochemical detection of truncated APC protein in sporadic human colorectal adenomas and adenocarcinomas

Mutations of the APC gene frequently occur in sporadic forms of colorectal adenomas and adenocarcinomas. Phenotypically, the vast majority of these mutations result in the truncation of the APC protein. To demonstrate the defective APC gene product in human colorectal tumors, rabbit region-specific antisera raised against the APC protein of amino acid sequences between 371 and 390 (SP1) and between 1821 and 1840 (SP3) were used to exhibit the truncated APC protein. In all, 86 lesions from 67 cases of sporadic adenoma and adenocarcinoma were examined; abnormal staining patterns were distinguished in 43 lesions (50%); the incidence of abnormalities was not significantly different between adenomas and carcinomas. The majority, 75% exhibited epitopic change with the SP1-positive and SP3-negative phenotype (type P1), and 25% exhibited neither of these phenotypes (type P2). The staining pattern in all lesions was uniform, and studies of carcinomas arising in adenomas showed the same pattern of staining. These findings supported the view that the APC lesion is a very early event in colorectal carcinogenesis. Furthermore, this simple immunohistochemical approach demonstrated that different adenomas from the same patient showed different staining patterns.

Monoclonal proliferation of double‐negative (CD4−CD8−) T‐cells bearing T‐Cell receptor‐αβ followed by subsequent development of Hodgkin's disease

Expression of CD4 or CD8 on the cell surface is an important guide for discriminating the immunologic functions of T‐cells. However, a minor T‐cell subset lacking both CD4 and CD8 molecules but bearing the usual form of T‐cell receptor (TCR)‐αβ (CD4−CD8−TCR‐αβ+ T‐cells) has recently been found not only in mice but also in humans, and the clinical relevance of this newly defined subpopulation to human diseases is now of considerable interest. The authors present a patient in whom CD4−CD8−TCR‐αβ+ T‐cells showed monoclonal proliferation in the peripheral blood for more than 3 years, then disappeared spontaneously, followed by subsequent development of Hodgkins disease. The pathologic roles of double‐negative T‐cell proliferation in this case are discussed from the viewpoint of premalignancy in lymphoproliferative diseases. Cancer 1994; 73:2818–23.