Misc - SAITOU Tsuyoshi

Proliferation-associated regulation of telomerase activity in human endometrium and its potential implication in early cancer diagnosis

T Saito, A Schneider, N Martel, H Mizumoto, M BulgayMoerschel, R Kudo, H Nakazawa

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS ( ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS )  231 ( 3 ) 610 - 614  1997.02

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Telomerase activity was detected in normal endometrium in association with proliferation and regulated during the menstrual cycle in a hormone-dependent manner. The activity was maximal at the late-proliferative phase to mid-secreting phase, and was absent or extremely low at early-proliferative phase and late-secreting phase. Activity was also detected in all endometrial simple hyperplasias tested (16 of 16) and in most cancers (25 of 30), but none was detected in endometrial of either pregnant or postmenopausal women ill the absence of hyperplasia. Our data provide evidence that the telomerase activity in postmenopausal endometrium reflects a hyperproliferative condition. Therefore, we conclude that telomerase can provide a novel marker for early endometrial cancer diagnosis. Hormone-dependent regulation of telomerase suggests the possibility of therapeutic and preventive strategies for endometrial cancers through the management of ovarian steroid hormones or other agents that regulate telomerase activity. (C) 1997 Academic Press.

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Connexin 37 mutations in rat hepatic angiosarcomas induced by vinyl chloride

T Saito, A Barbin, Y Omori, H Yamasaki

CANCER RESEARCH ( AMER ASSOC CANCER RESEARCH )  57 ( 3 ) 375 - 377  1997.02

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Connexin genes have been shown to restore normal cell growth when transfected into certain tumorigenic cells and thus are considered to form a family of tumor suppressor genes, In this study, we have analysed mutations of the connexin 37 (Cx37) gene in rat hepatic angiosarcomas induced by vinyl chloride. A total of 25 rat liver tumors (22 hepatic angiosarcomas and 3 hepatocellular carcinomas) were analysed by PCR-single-strand conformation polymorphism analysis and DNA sequencing, Four mutations were detected in three tumors: (a) one GGG(Gly) to GAG(Glu) mutation at codon 168; and (b) three silent mutations, CGA(Arg) to CGC(Arg), at codon 166, In addition, we found that codon 88 is polymorphic (GAG(Glu) to GAA(Glu)). Cx37 proteins are detectable in endothelial cells of normal liver by immunohistochemical analysis, but none of the angiosarcomas showed Cx37-positive spots, These results suggest that Cx37-mediated gap junctional intercellular communication may be disturbed in most of these angiosarcomas, but mutation of the Cx37 gene is rare.

A new operative procedure for vaginal extended hysterectomy

J Gynecol Tech   3   41 - 51  1997

Expression of component desmosomal proteins in uterine endometrial carcinoma and their relation to cellular differentiation

H Nei, T Saito, H Tobioka, E Itoh, M Mori, R Kudo

CANCER ( WILEY-LISS )  78 ( 3 ) 461 - 470  1996.08

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BACKGROUND. While the assessment of the malignancy of neoplasms is based on morphologic studies of cells and tissues, use of objective molecular markers is leading to a better understanding and more biologically meaningful classification of neoplasms. In recent years, changes in the expression of cell adhesion molecules, especially E-cadherin, catenin, and adenomatous polyposis coli (APC), in carcinomas have attracted the attention of researchers. However, little is known about desmosomes in the uterine endometrium or in endometrial carcinomas. In this study, we semiquantified the desmosomal components desmoplakin I and II and desmoglein, in tissue sections using confocal laser scanning microscopy (LSM), and examined their relationship to the pathological type, the occurrence of lymph node metastases, and the extent of myometrial invasion. METHOD, Frozen sections of 31 specimens of normal endometrium, 5 specimens of atypical hyperplasia, and 41 specimens of endometrial carcinoma were stained by the immunofluorescence method using antidesmoplakin I and II and antidesmoglein, and these markers were then semiquantified in tissue sections by LSM. RESULTS, The expression and location of desmoplakin I and II and desmoglein were similar, and their expression decreased with loss of differentiation. The expression was lower in cases of lymph node metastasis than in negative cases and was lower in the cases with > one-half myometrial invasion than in cases with < one-half myometrial invasion. CONCLUSIONS. Reduction of desmoplakin I and II and desmoglein expression may play an important role in the invasiveness and metastatic activity of human endometrial carcinoma. They can therefore be used as differentiation markers for endometrial carcinoma. (C) 1996 American Cancer Society.

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内視鏡と膣拡大鏡診, 生検診の方法

図説産婦人科VIEW   17   184 - 187  1995

生検診の方法

図説産婦人科VIEW，14内視鏡と膣拡大鏡診，メジカルビュー社    1995

MONOCLONAL-ANTIBODY 7H6 REACTS WITH A NOVEL TIGHT JUNCTION-ASSOCIATED PROTEIN DISTINCT FROM ZO-1, CINGULIN AND ZO-2

Y ZHONG, T SAITOH, T MINASE, N SAWADA, K ENOMOTO, M MORI

JOURNAL OF CELL BIOLOGY ( ROCKEFELLER UNIV PRESS )  120 ( 2 ) 477 - 483  1993.01

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The tight junction is an essential element of the intercellular junctional complex; yet its protein composition is not fully understood. At present, only three proteins, ZO-1 (Stevenson, B. R., J. D. Siliciano, M. S. Mooseker, and D. A. Goodenough. 1986. J. Cell Biol. 103:755-766), cingulin (Citi, S., H. Sabanay, R. Jakes, B. Geiger, and J. Kendrick-Jones. 1988. Nature (Lond.). 333:272-275) and ZO-2 (Gumbiner, B., T. Lowenkopf, and D. Apatira. 1991. Proc. Natl. Acad. Sci. USA. 88:3460-3464) are known to be associated with the tight junction. We have generated a monoclonal antibody (7H6) against a bile canaliculus-rich membrane fraction prepared from rat liver. This 7H6 antigen was preferentially localized by immunofluorescence at the junctional complex regions of hepatocytes and other epithelia, and 7H6-affiliated gold particles were shown electron microscopically to localize at the periphery of tight junctions. Immunoblot analysis of a bile canaliculus-rich fraction of rat liver using 7H6, anti-ZO-1 antibody (R26.4C), and anticingulin antibody revealed that 7H6 reacted selectively with a 155-kD protein, whereas R26.4C reacted only with a 225-kD protein. Anti-cingulin antibody reacted solely with 140 and 108-kD proteins, indicating that the protein recognized by 7H6 is immunologically different from ZO-1 and cingulin. Immunoprecipitation of detergent extracts obtained from metabolically labeled MDCK cells with R26.4C coprecipitated a 160-kD protein, which corresponds to ZO-2, with ZO-1. However, 7H6 did not react with the 160-kD protein. These results strongly suggest that the 7H6 antibody recognizes a novel tight junction-associated protein different from ZO-1, cingulin and ZO-2.

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ULTRASTRUCTURAL DEMONSTRATION OF PRE-S2 ANTIGEN ON THE INFECTED LIVER-CELL SURFACE

T SAITO, H SHINZAWA, T TAKAHASHI, M ISHIKAWA

HEPATOLOGY ( W B SAUNDERS CO )  12 ( 4 ) 884 - 884  1990.10

Research paper, summary (international conference)  

A MALIGNANT MIXED MESODERMAL TUMOR OF THE UTERINE CORPUS WITH HYPERCATECHOLAMINEMIA

T UEDE, T SAITO, T MINASE, T MIURA, K KIKUCHI, O IIMURA, S KON, H IWAKI, M MORI, K KIKUCHI

ACTA PATHOLOGICA JAPONICA ( BLACKWELL SCIENCE )  40 ( 4 ) 293 - 300  1990.04

A case study of malignant Brenner tumor ; a histologic, immunohistochemical, and ultrastructural study

J. Clin. Electron Microscopy   23   880 - 881  1990