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Featured researches published by Yoshiaki Inayama.


Human Pathology | 1997

Expression of gelatinase A, tissue inhibitor of metalloproteinases-2, matrilysin, and trypsin(ogen) in lung neoplasms: An immunohistochemical study

Naomi Kawano; Hiroyuki Osawa; Takaaki Ito; Yoji Nagashima; Fumiki Hirahara; Yoshiaki Inayama; Yukio Nakatani; Seiko Kimura; Hiroyuki Kitajima; Naohiko Koshikawa; Kaoru Miyazaki; Hitoshi Kitamura

Lung cancer is a heterogeneous tumor in terms of clinical and biological behavior, and its aggressiveness depends on its invasive and metastatic properties. Matrix metalloproteinases and serine proteinases are believed to play a crucial role in invasion and metastasis of malignant tumor cells. In the present study, the authors evaluated immunohistochemically the expression of gelatinase A; tissue inhibitor of metalloproteinases-2 (TIMP-2), an inhibitor of gelatinase A; matrilysin; and trypsin(ogen) in 67 lung tumors from a variety of histological types including 17 squamous cell carcinomas, 16 adenocarcinomas, 15 small cell carcinomas, and 12 carcinoids. Interestingly, normal bronchial, bronchiolar, and alveolar epithelial cells expressed gelatinase A, TIMP-2, matrilysin, and trypsin(ogen) at varying frequencies and intensities. Bronchial smooth muscle cells and cartilage cells expressed gelatinase A alone, whereas endothelial cells, fibroblasts, and macrophages expressed gelatinase A and TIMP-2. Gelatinase A was expressed at high levels in most lung tumors examined (47% to 80%). TIMP-2 was also expressed at high levels except in the small cell carcinomas, which showed TIMP-2 expression at a lower frequency (60%) compared with other types of lung tumors (80% to 100%). Although matrilysin was expressed by tumor cells of all the histological types at various frequencies (13% to 63%), its expression was most common in adenocarcinomas. Expression of trypsin(ogen) was observed almost exclusively in adenocarcinomas (56%); other types of lung tumors expressed trypsin(ogen) far less frequently (0% to 12%). The present results, taken together with those of previous studies, suggest that gelatinase A is associated with malignant behavior of all the types of lung tumors, whereas its activity may be controlled by the endogenous inhibitor TIMP-2. The aggressive clinical behavior of small cell carcinoma may be attributable, at least in part, to a loss of the inhibitory effect of TIMP-2, as a significant proportion of these tumors showed negative or low levels of TIMP-2 expression. Matrilysin and trypsin(ogen) expressions are unlikely to be correlated with the aggressiveness of lung tumors. The expression of trypsin (ogen) may rather reflect the differentiation of adenocarcinoma cells toward normal airway epithelial cells.


The Journal of Pathology | 2005

Gene expression analysis of renal carcinoma: adipose differentiation-related protein as a potential diagnostic and prognostic biomarker for clear-cell renal carcinoma

Masahiro Yao; Hisahiro Tabuchi; Yoji Nagashima; Masaya Baba; Noboru Nakaigawa; Hitoshi Ishiguro; Kenji Hamada; Yoshiaki Inayama; Takeshi Kishida; Keiko Hattori; Hisafumi Yamada-Okabe; Yoshinobu Kubota

The gene expression profiles of 33 renal cell carcinomas (RCCs) and nine normal kidney samples were examined using high‐density oligonucleotide microarrays in an attempt to identify biomolecular markers for the diagnosis of tumour subtypes and also for prediction of prognosis. Hierarchical clustering demonstrated that clear‐cell RCC, chromophobe RCC, and normal kidney tissue showed distinctive gene expression profiles. The mean expression levels of 149 of 12 500 genes were more than three times higher in clear‐cell RCC than in chromophobe RCC and normal kidney tissue. Among the genes whose expression was upregulated in clear‐cell RCC, adipose differentiation‐related protein (ADFP) and nicotinamide N‐methyltransferase (NNMT) were selected for further analysis. Consistent with the results of the microarray, increased levels of ADFP and NNMT mRNA were found more frequently in clear‐cell RCCs than in other non‐clear‐cell tumour subtypes using real‐time quantitative PCR. Immunohistochemistry for ADFP showed strong and unique tumour cell staining patterns in the majority of clear‐cell RCCs. More importantly, patients bearing tumours with higher AFDP mRNA levels showed significantly better survival in both univariate and multivariate analyses. ADFP is a lipid storage droplet‐associated protein and its transcription is considered to be regulated by the von Hippel–Lindau/hypoxia‐inducible factor pathway. It is known that clear‐cell RCC contains abundant lipids and cholesterols. Thus it is likely that sustained upregulation of ADFP following VHL inactivation is involved in the morphological appearance of clear‐cell RCC. Moreover ADFP expression status may provide useful prognostic information as a biomolecular marker in patients with clear‐cell RCC. Copyright


The American Journal of Surgical Pathology | 1996

Atypical adenomatous hyperplasia and bronchoalveolar lung carcinoma: Analysis by morphometry and the expressions of p53 and carcinoembryonic antigen

Hitoshi Kitamura; Yoichi Kameda; Nobuo Nakamura; Yoshiaki Inayama; Yukio Nakatani; Tokuhiko Shibagaki; Takaaki Ito; Hiroyuki Hayashi; Hirokazu Kimura; Masayoshi Kanisawa

Atypical adenomatous hyperplasia (AAH) of the lung is a putative precursor of bronchoalveolar carcinoma (BAC). To define the steps in its development and to clarify at which stage critical cellular events occur, we studied 65 lesions of AAH, early BAC, and overt BAC by morphometric analysis and immunohistochemical evaluation of expression of p53 protein and carcinoembryonic antigen (CEA). Both the nuclear area and lesion size increased from AAH to early BAC and to overt BAC; the standardized variation of nuclear area was smallest in overt BAC. Discriminant analysis using these morphometric parameters revealed high accuracy rates for the respective categories. Analysis of distribution of lung lesions in terms of nuclear area and lesion size yielded effective, potentially diagnostic cutoff values for distinction between AAH and early BAC. Both p53 and CEA expression tended to increase with the advance of atypia grade. In particular, high-level p53 expression was strongly correlated with overt BAC. These findings indicate that our classification of lung lesions is reproducible and thus useful for analyzing the development of BAC. Furthermore, some kinds of p53 gene abnormalities that are correlated with high-level p53 expression likely play an important role in the progression of early to overt BAC.


Virchows Archiv | 2000

Interstitial pneumonia in Hermansky-Pudlak syndrome: significance of florid foamy swelling/degeneration (giant lamellar body degeneration) of type-2 pneumocytes

Yukio Nakatani; Nobuo Nakamura; Jinyu Sano; Yoshiaki Inayama; Naomi Kawano; Shoji Yamanaka; Yohei Miyagi; Yoji Nagashima; Chiho Ohbayashi; Mutsue Mizushima; Toshiaki Manabe; Makoto Kuroda; Toyoharu Yokoi; Osamu Matsubara

Abstract Although usual interstitial pneumonia (UIP)-like IP has been known as the most serious complication of Hermansky-Pudlak syndrome (HPS), its pathologic features and pathogenesis are poorly understood. We investigated biopsied and autopsied lung tissues from five patients who died of UIP-like IP associated with HPS (HPSIP). The salient histopathologic features of HPSIP observed were: (1) alveolar septa displaying florid proliferation of type-2 pneumocytes (2PCs) with characteristic foamy swelling/degeneration; (2) patchy fibrosis with lymphocytic and histiocytic infiltration centered around respiratory bronchioles, occasionally showing constrictive bronchiolitis; and (3) honeycomb change without predilection for the lower lobes or subpleural area. Those peculiar 2PCs were histochemically characterized by the over accumulation of phospholipid, immunohistochemically by a weak positivity for surfactant protein, and ultrastructurally by the presence of numerous giant lamellar bodies that compressed the nucleus with occasional cytoplasmic disruption, together suggesting a form of cellular degeneration with an over accumulation of surfactant (giant lamellar body degeneration). The present study strongly indicates that there is a basic defect in the formation/secretion process of surfactant by the 2PCs in HPS, which may well be the triggering factor for the HPSIP development. Other factors, such as macrophage dysfunction, may be working synergistically for further acceleration of the inflammatory process.


The American Journal of Surgical Pathology | 1998

Pulmonary Adenocarcinomas of the Fetal Lung Type: A Clinicopathologic Study Indicating Differences in Histology, Epidemiology, and Natural History of Low-grade and High-grade Forms

Yukio Nakatani; Hitoshi Kitamura; Yoshiaki Inayama; Seiko Kamijo; Yoji Nagashima; Kiyoshi Shimoyama; Nobuo Nakamura; Jinyu Sano; Nobuo Ogawa; Tokuhiko Shibagaki; Milan Resl; Eugene J. Mark

Seven cases of high-grade adenocarcinoma of fetal lung type (H-FLAC) are compared with nine cases of pulmonary endodermal tumor resembling fetal lung or low-grade adenocarcinoma of fetal lung type (L-FLAC). Of the seven patients with of H-FLAC, four were men and three were women. All of the patients but one were in their 60s or 70s. Five patients were smokers. After resection of the tumor, three patients died of metastases, two patients are alive with no evidence of disease, and two patients died of a postoperative complication. Histologically, H-FLAC and L-FLAC have both complex glandular structures resembling fetal lung and neuroendocrine differentiation. Two cases of H-FLAC had stromal proliferation typical of biphasic pulmonary blastoma. The H-FLAC was distinguished from L-FLAC by the presence of disorganized glands, large vesicular nuclei, prominent nucleoli, pronounced anisonucleosis, absence of morules, transition to conventional adenocarcinoma, broad areas of necrosis, desmoplastic stroma, overexpression of p53 protein, and production of alpha-fetoprotein. High and low grades of FLAC explain discrepancies in previously reported clinicopathologic features of FLAC. The H-FLAC needs to be distinguished from L-FLAC. Both forms may have stromal components, so both have been referred to as blastomas. The H-FLAC represents the prototype of so-called pulmonary blastoma predominantly seen in the elderly, whereas L-FLAC and its biphasic form predominate in the middle-aged population.


Human Pathology | 2008

The overexpression and altered localization of the atypical protein kinase C λ/ι in breast cancer correlates with the pathologic type of these tumors

Yasuyuki Kojima; Kazunori Akimoto; Yoji Nagashima; Hitoshi Ishiguro; Sumiko Shirai; Takashi Chishima; Yasushi Ichikawa; Takashi Ishikawa; Takeshi Sasaki; Yoshinobu Kubota; Yoshiaki Inayama; Ichiro Aoki; Shigeo Ohno; Hiroshi Shimada

Breast cancer is one of the common malignant diseases among women in Japan as well as in western countries, and its incidence continues to increase. Normal mammary duct epithelial cells exhibit a well-organized apicobasal polarity, which forms the basis for their specific structure and function. Although the loss of epithelial cell polarity is one of the major changes that occur during the progression of tumor cells, including breast cancer, the underlying molecular mechanisms for this, as well as their relationship to other changes such as increased proliferation and metastasis, remain to be elucidated. The atypical protein kinase C lambda/iota (aPKC lambda/iota) is involved in several signal transduction pathways, including the establishment of epithelial cell polarity. In this study we evaluated the expression and localization of aPKC lambda/iota in breast cancer by immunohistochemistry and compared our findings with the clinicopathologic factors associated with the tumor specimens. We detected aPK Clambda/iota protein overexpression in 88 of the 110 breast cancer cases (80.0%) under study, expect for decreased expression in a few cases. The immunoreactivity of aPK Clambda/iota was generally weak in ductal carcinoma in situ, but strong in invasive ductal carcinoma (IDC; P = .022). The correlation between apical or cytoplasmic aPKC lambda/iota localization and tumor pathologic type (ie, atypical ductal hyperplasia, ductal carcinoma in situ. or IDC) was also demonstrated (P < .001). These results thus indicate that the normal apicobasal polarity is lost upon the progression of a breast lesion to IDC. This is also the first evidence to show aPKC lambda/iota overexpression in breast cancer and demonstrates that its localization is associated with the trend of pathologic type of the tumor.


Modern Pathology | 2002

Aberrant Nuclear Localization and Gene Mutation of β-catenin in Low-Grade Adenocarcinoma of Fetal Lung Type: Up-Regulation of the Wnt Signaling Pathway May Be a Common Denominator for the Development of Tumors that Form Morules

Yukio Nakatani; Katsuhiko Masudo; Yohei Miyagi; Yoshiaki Inayama; Naomi Kawano; Yukichi Tanaka; Keisuke Kato; Takaaki Ito; Hitoshi Kitamura; Yoji Nagashima; Shoji Yamanaka; Nobuo Nakamura; Jinyu Sano; Nobuo Ogawa; Naoki Ishiwa; Kenji Notohara; Milan Resl; Eugene J. Mark

The salient histopathologic features of low-grade adenocarcinoma of the fetal lung type (L-FLAC)/well-differentiated fetal adenocarcinoma (WDFA) include complex glandular structures and morules with biotin-rich optically clear nuclei. Interestingly, these characteristic features are shared by the cribriform-morular variant of papillary thyroid carcinoma, whose morphology is identical to that of familial adenomatous polyposis (FAP)-associated thyroid carcinoma. Furthermore, the single reported case of lung cancer associated with FAP was L-FLAC/WDFA. These observations lead us to hypothesize that up-regulation of the Wnt signaling pathway underlies the development of L-FLAC/WDFA. To verify this hypothesis, 11 cases of L-FLAC/WDFA, including the one FAP-associated case, eight cases of high-grade adenocarcinoma of the fetal lung type (H-FLAC), 24 cases of conventional pulmonary adenocarcinoma (CAC), and 13 fetal lungs were immunostained for β-catenin. All cases of L-FLAC/WDFA showed predominantly aberrant nuclear/cytoplasmic expression, especially in budding glands and morules, whereas six of eight cases (75%) of H-FLAC and all but one case (96%) of CAC showed predominantly membranous expression. Fetal lungs showed nuclear/cytoplasmic expression restricted to the distal branching airway epithelium. Mutational analysis of exon 3 of the β-catenin gene in five sporadic cases of L-FLAC/WDFA showed a point mutation at codon 34 and codon 37 in two cases, respectively. The present study indicates that up-regulating disturbances in the Wnt signaling pathway, including mutation of the β-catenin gene, underlie tumorigenesis of L-FLAC/WDFA. The expression pattern of β-catenin in L-FLAC/WDFA resembles that of the developing fetal lung airway. With the expression pattern of β-catenin as a marker, most cases of H-FLAC as well as CAC appear to have different oncogenic pathways from cases of L-FLAC/WDFA. The present study together with other available data also suggests that abnormal up-regulation of the Wnt signaling pathway may be a common denominator for the development of tumors with morular formation from a variety of anatomic sites.


Histopathology | 2001

Pulmonary artery dissection in patients without underlying pulmonary hypertension

Yoshiaki Inayama; Yukio Nakatani; H Kitamura

Pulmonary artery dissection in patients without underlying pulmonary hypertension


BJUI | 2009

Usefulness of the 2005 International Society of Urologic Pathology Gleason grading system in prostate biopsy and radical prostatectomy specimens

Hiroji Uemura; Koji Hoshino; Takeshi Sasaki; Yasuhide Miyoshi; Hitoshi Ishiguro; Yoshiaki Inayama; Yoshinobu Kubota

To determine whether the 2005 International Society of Urologic Pathology (ISUP) Gleason Grading Consensus is clinically more useful than the conventional Gleason score (CGS), we compared the CGS and ISUP GS (IGS) of prostate needle biopsy (NB) and radical prostatectomy (RP) specimens, and evaluated the prognostic value of the ISUP GS.


Lancet Oncology | 2016

Metformin for chemoprevention of metachronous colorectal adenoma or polyps in post-polypectomy patients without diabetes: a multicentre double-blind, placebo-controlled, randomised phase 3 trial

Takuma Higurashi; Kunihiro Hosono; Hirokazu Takahashi; Yasuhiko Komiya; Shotaro Umezawa; Eiji Sakai; Takashi Uchiyama; Leo Taniguchi; Yasuo Hata; Shiori Uchiyama; Akiko Hattori; Hajime Nagase; Takaomi Kessoku; Jun Arimoto; Nobuyuki Matsuhashi; Yoshiaki Inayama; Shoji Yamanaka; Masataka Taguri; Atsushi Nakajima

BACKGROUND The prevalence of, and mortality from, colorectal cancer is increasing worldwide, and new strategies for prevention are needed to reduce the burden of this disease. The oral diabetes medicine metformin might have chemopreventive effects against cancer, including colorectal cancer. However, no clinical trial data exist for the use of metformin for colorectal cancer chemoprevention. Therefore, we devised a 1-year clinical trial to assess the safety and chemopreventive effects of metformin on sporadic colorectal cancer (assessed by adenoma and polyp recurrence) in patients with a high risk of adenoma recurrence. METHODS This trial was a multicentre, double-blind, placebo-controlled, randomised phase 3 trial. Non-diabetic adult patients who had previously had single or multiple colorectal adenomas or polyps resected by endoscopy were enrolled into the study from five hospitals in Japan. Eligible patients were randomly assigned (1:1) to receive oral metformin (250 mg daily) or identical placebo tablets by a stratified computer-based randomisation method, with stratification by institute, age, sex, and body-mass index. All patients, endoscopists, doctors, and investigators were masked to drug allocation until the end of the trial. After 1 year of administration of metformin or placebo, colonoscopies were done to assess the co-primary endpoints: the number and prevalence of adenomas or polyps. Our analysis included all participants who underwent random allocation, according to the intention-to-treat principle. This trial is registered with University Hospital Medical Information Network (UMIN), number UMIN000006254. FINDINGS Between Sept 1, 2011, and Dec 30, 2014, 498 patients who had had single or multiple colorectal adenomas resected by endoscopy were enrolled into the study. After exclusions for ineligibility, 151 patients underwent randomisation: 79 were assigned to the metformin group and 72 to the placebo group. 71 patients in the metformin group and 62 in the placebo group underwent 1-year follow-up colonoscopy. The prevalence of total polyps (hyperplastic polyps plus adenomas) and of adenomas in the metformin group was significantly lower than that in the placebo group (total polyps: metformin group 27 [38·0%; 95% CI 26·7-49·3] of 71 patients, placebo group 35 [56·5%; 95% CI 44·1-68·8] of 62; p=0·034, risk ratio [RR] 0·67 [95% CI 0·47-0·97]; adenomas: metformin group 22 [30·6%; 95% CI 19·9-41·2] of 71 patients, placebo group 32 [51·6%; 95% CI 39·2-64·1] of 62; p=0·016, RR 0·60 [95% CI 0·39-0·92]). The median number of polyps was zero (IQR 0-1) in the metformin group and one (0-1) in the placebo group (p=0·041). The median number of adenomas was zero (0-1) in the metformin group and zero (0-1) in the placebo group (p=0·037). 15 (11%) of patients had adverse events, all of which were grade 1. We recorded no serious adverse events during the 1-year trial. INTERPRETATION The administration of low-dose metformin for 1 year to patients without diabetes was safe. Low-dose metformin reduced the prevalence and number of metachronous adenomas or polyps after polypectomy. Metformin has a potential role in the chemoprevention of colorectal cancer. However, further large, long-term trials are needed to provide definitive conclusions. FUNDING Ministry of Health, Labour and Welfare, Japan.

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Yukio Nakatani

Yokohama City University

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Yoji Nagashima

Yokohama City University

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Takaaki Ito

Yokohama City University

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Shoji Yamanaka

Yokohama City University Medical Center

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Kensuke Kubota

Yokohama City University

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Masahiro Yao

Yokohama City University

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