Faculty Profiles - IWAMURO Masaya

Papers - IWAMURO Masaya

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Restored expression of the tumor suppressor gene RUNX3 reduces cancer stem cells in hepatocellular carcinoma by suppressing Jagged1-Notch signaling Reviewed

Shin-Ichi Nishina, Hidenori Shiraha, Yutaka Nakanishi, Shigetomi Tanaka, Minoru Matsubara, Nobuyuki Takaoka, Masayuki Uemura, Shigeru Horiguchi, Junro Kataoka, Masaya Iwamuro, Takahito Yagi, Kazuhide Yamamoto

ONCOLOGY REPORTS 26 ( 3 ) 523 - 531 2011.9

Prospects for Induced Pluripotent Stem Cell-Derived Hepatocytes in Cell Therapy¹ Reviewed

Masaya Iwamuro, Javed M. Shahid, Kazuhide Yamamoto, Naoya Kobayashi

Cell Medicine 2 ( 1 ) 1 2011.1

Loss of runt-related transcription factor 3 expression leads hepatocellular carcinoma cells to escape apoptosis Reviewed

Yutaka Nakanishi, Hidenori Shiraha, Shin-ichi Nishina, Shigetomi Tanaka, Minoru Matsubara, Shigeru Horiguchi, Masaya Iwamuro, Nobuyuki Takaoka, Masayuki Uemura, Kenji Kuwaki, Hiroaki Hagihara, Junichi Toshimori, Hideki Ohnishi, Akinobu Takaki, Shinichiro Nakamura, Yoshiyuki Kobayashi, Kazuhiro Nouso, Takahito Yagi, Kazuhide Yamamoto

BMC CANCER 11 3 2011.1

Endoscopic hemostasis for hemorrhage from an ileal diverticulum Reviewed

Masaya Iwamuro

World Journal of Gastrointestinal Endoscopy 3 ( 7 ) 154 2011

Endoscopic features and prognoses of mantle cell lymphoma with gastrointestinal involvement Reviewed

Masaya Iwamuro, Hiroyuki Okada, Yoshiro Kawahara, Katsuji Shinagawa, Toshiaki Morito, Tadashi Yoshino, Kazuhide Yamamoto

WORLD JOURNAL OF GASTROENTEROLOGY 16 ( 37 ) 4661 - 4669 2010.10

COMBINED DUODENAL STENT PLACEMENT AND ENDOSCOPIC ULTRASONOGRAPHY-GUIDED BILIARY DRAINAGE FOR MALIGNANT DUODENAL OBSTRUCTION WITH BILIARY STRICTURE Reviewed

Masaya Iwamuro, Hirofumi Kawamoto, Ryo Harada, Hironari Kato, Ken Hirao, Osamu Mizuno, Etsuji Ishida, Tsuneyoshi Ogawa, Hiroyuki Okada, Kazuhide Yamamoto

DIGESTIVE ENDOSCOPY 22 ( 3 ) 236 - 240 2010.7

Hepatic differentiation of mouse iPS cells in vitro. Reviewed International journal

Masaya Iwamuro, Toshiyuki Komaki, Yasuhiro Kubota, Masayuki Seita, Hironobu Kawamoto, Takeshi Yuasa, Javed M Shahid, Reham A R A Hassan, Wael A R A Hassan, Shuhei Nakaji, Yuriko Nishikawa, Eisaku Kondo, Kazuhide Yamamoto, Ira J Fox, Naoya Kobayashi

Cell transplantation 19 ( 6 ) 841 - 7 2010

Language：English Publisher：Cognizant Electronic Publishing

Induced pluripotent stem (iPS) cells are pluripotent and are able to unlimitedly proliferate in vitro. This technical breakthrough in creating iPS cells from somatic cells has noteworthy implications for overcoming the immunological rejection and the ethical issues associated with the derivation of embryonic stem cells from embryos. In the current work, we present an efficient hepatic differentiation of mouse iPS cells in vitro. iPS cells were cultured free floating to induce the formation of embryoid bodies (EB) for 5 days. EB were transferred to a gelatin-coated plate and treated with 100 ng/ml activin A and 100 ng/ml basic fibroblast growth factor (bFGF) for 3 days to induce definitive endoderm. Cells were further cultured for 8 days with 100 ng/ml hepatocyte growth factor (HGF) to generate hepatocytes. Characterization was performed by RT-PCR assay. Functional analysis for albumin secretion and ammonia removal was also carried out. iPS cell-derived hepatocyte-like cells (iPS-Heps) were obtained at the end of the differentiation program. Expression levels of a gestational hepatocyte gene and lineage-specific hepatic genes intensified in iPS-Heps. The production of albumin increased in a time-dependent manner. iPS-Heps were capable of metabolizing ammonia. We present here instant hepatic differentiation of mouse iPS cells using combined 3-day treatments of activin A and bFGF with subsequent 8-day HGF. Our study will be an important step to generate hepatocytes from human iPS cells as a new source for liver-targeted cell therapies.

DOI： 10.3727/096368910X508960

PubMed

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Comparative analysis of endoderm formation efficiency between mouse ES cells and iPS cells. Reviewed International journal

Cell transplantation 19 ( 6 ) 831 - 9 2010

Language：English Publisher：Cognizant Electronic Publishing

Definitive endoderm (DE) derived from stem cells holds potential to differentiate into hepatocytes. Stem cell therapy using those cells has potential for a treatment of liver disease. To date, various ways of inducing hepatocytes from embryonic stem (ES) cells have been reported by researchers. However, it has not been proved enough that induced pluripotent stem (iPS) cells behave in the same manner as ES cells in endoderm differentiation. The purpose of this study was to establish an efficient method to induce DE from iPS cells, through comparatively analyzing the efficacy of endoderm formation from mouse ES cells. Furthermore, the efficiency of a serum-free medium in the differentiation into DE was investigated. Mouse ES cells and iPS cells were floated in culture medium for 2 or 5 days and embryoid bodies (EB) were formed. Subsequently, DE was induced with 100 ng/ml activin A and 100 ng/ml basic fibroblast growth factor (bFGF). RT-PCR and real-time PCR analyses were carried out at each step to determine the gene expression of EB markers. The difference in cellular proliferation between serum-containing and serum-free media was examined by an MTS assay in EB and DE induction. iPS cells showed the paralleled mRNA expression to ES cells in each step of differentiation into EB, but the levels of expression of Sox17 and Foxa2 were relatively higher in ES cell-derived DE, whereas Cxcr4 expression was higher in iPS cell-derived DE. The utilization of serum-free medium for iPS cells showed significantly favorable cellular proliferation during EB formation and subsequent DE induction. Forming EB for 5 days and subsequently DE induction with activin A and bFGF with serum-free medium was an appropriate protocol in iPS cells. This may represent an important step for generating hepatocytes from iPS cells for the development of cell therapy.

DOI： 10.3727/096368910X508951

PubMed

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Establishment of an Immortalized Porcine Liver Cell Line JSNK-1 With Retroviral Transduction of SV40T Reviewed

Javed M. Shahid, Masaya Iwamuro, Hiromi Sasamoto, Yasuhiro Kubota, Masayuki Seita, Hironobu Kawamoto, Shuhei Nakaji, Hirofumi Noguchi, Kazuhide Yamamoto, Naoya Kobayashi

CELL TRANSPLANTATION 19 ( 6-7 ) 849 - 856 2010

Treatment of acute liver failure in mice by hepatocyte xenotransplantation. Reviewed International journal

Tsuyoshi Yamamoto, Nalú Navarro-Alvarez, Alejandro Soto-Gutierrez, Takeshi Yuasa, Masaya Iwamuro, Yasuhiro Kubota, Masayuki Seita, Hironobu Kawamoto, Shahid M Javed, Eisaku Kondo, Hirofumi Noguchi, Satoru Kobayashi, Shuhei Nakaji, Naoya Kobayashi

Cell transplantation 19 ( 6 ) 799 - 806 2010

Language：English

Liver diseases still have a high mortality even though liver transplantation has become a standard treatment. Currently, hepatocyte transplantation has been proposed as another promising strategy. One limitation is the availability of human livers as a source of hepatocytes. Because of an unlimited supply, the use of porcine hepatocytes might address this problem. Regardless of the source, once isolated hepatocytes lose specific functionality due to the loss of the natural microenvironment. For this reason, we tested the ability of a self-assembling peptide nanofiber (SAPNF) to provide a provisional three-dimensional (3D) support to interact with cells to control their function in vivo. Isolated porcine hepatocytes were embedded in SAPNF, or collagen type I and transplanted by direct injection into the splenic pulp of SCID mice suffering from acute liver failure (ALF) by 90% hepatectomy. SAPNF porcine hepatocyte transplantation produced engraftment that was far superior to that obtained using collagen and prolonged the survival of mice with ALF, in contrast with controls. An ultrastructural evaluation using transmission electron microscopy indicated extensive cell-cell communication and preservation of hepatocyte architecture. The transplanted SAPNF hepatocytes showed higher expression of albumin and PAS and lower apoptotic events assessed by TUNEL staining. Hepatocytes culture in a truly 3D network allows in vivo maintaining of differentiated functions, and once transplanted between widely divergent species can function to correct acute liver failure in mice and prolong their survival.

DOI： 10.3727/096368910X508915

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Characteristics of CD133(+) human colon cancer SW620 cells. Reviewed International journal

Hironobu Kawamoto, Takeshi Yuasa, Yasuhiro Kubota, Masayuki Seita, Hiromi Sasamoto, Javed M Shahid, Takahiro Hayashi, Hiroyuki Nakahara, Reham Hassan, Masaya Iwamuro, Eisaku Kondo, Shuhei Nakaji, Noriaki Tanaka, Naoya Kobayashi

Cell transplantation 19 ( 6 ) 857 - 64 2010

Language：English

Worldwide, colorectal cancer is the third most common type of cancer affecting both sexes. It has been proposed that a small subset of cancer cells (cancer stem cells) within each tumor is able to initiate tumor growth. In 2007, two research groups simultaneously identified a colon cancer stem cell population in human tumors by the use of CD133 expression. In the present study, we used a human colon cancer cell line, SW620, to analyze the cancer stem cell-like characteristics of CD133(+) cells in vitro and in vivo. In vitro, CD133(+) SW620 cells had a higher proliferative capacity, were more irradiation- and chemotherapy-resistant, and had a higher expression of β-catenin compared with CD133(-) cells. Injections of either CD133(+) or CD133(-) cells into the skin or rectal mucosa of NOD/SCID mice led to tumors; however, injection of CD133(+) cells resulted in the formation of larger tumors. Tumors derived from injections of CD133(-) cells did not contain any CD133(+) cells, whereas tumors derived from injections of CD133(+) cells did contain CD133(+) cells, suggesting self-renewing capability. However, the proportion of CD133(+) cells in the newly formed tumors in vivo was lower than the proportion of CD133(+) cells in vitro. In conclusion, the human colon cancer cell line, SW620, contains both CD133(+) and CD133(-) phenotypes, and the CD133(+) phenotype has characteristics consistent with those of cancer stem cells.

DOI： 10.3727/096368910X508988

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Two Cases of Primary Small Cell Carcinoma of the Stomach Reviewed

Masaya Iwamuro, Shouichi Tanaka, Akihiro Bessho, Hideaki Takahashi, Takeyuki Ohta, Rie Takada, Ichiro Murakami

ACTA MEDICA OKAYAMA 63 ( 5 ) 293 - 298 2009.10

Endoscopic removal of a fishhook in the esophagus Reviewed

Masaya Iwamuro, Hiroyuki Okada, Daisuke Kawai, Osamu Mizuno, Shunsuke Saito, Ryuta Takenaka, Yoshiro Kawahara, Kazuhide Yamamoto

GASTROINTESTINAL ENDOSCOPY 70 ( 3 ) 550 - 551 2009.9

A case of cholangiolocellular carcinoma asynchronously developing 3 years after the resection of hepatocellular carcinoma Reviewed

Masaya Iwamuro, Hirofumi Kawamoto, Tsuneyoshi Ogawa, Takehiro Tanaka, Takahito Yagi, Kazuhide Yamamoto

Clinical Journal of Gastroenterology 2 ( 3 ) 204 - 209 2009.6

好酸球性胆嚢炎と考えられた2例

岩室雅也, 河本博文, 浅野基, 三好智子, 佐田憲映, 岡田裕之, 小出典男, 山本和秀

治療 91 ( 5 ) 1611 - 1614 2009.5

A case of primary intracranial hemangiopericytoma with hepatic metastases: Successful treatment with radiofrequency ablation and transcatheter arterial chemoembolization Reviewed

Masaya Iwamuro, Shinichiro Nakamura, Hidenori Shiraha, Yoshiyuki Kobayashi, Hirotoshi Fukatsu, Kazuhide Yamamoto

Clinical Journal of Gastroenterology 2 ( 1 ) 30 - 35 2009.2

Eosinophilic Cholangitis with Initial Clinical Features Indistinguishable from IgG4-Related Cholangitis Reviewed

Masaya Iwamuro, Kazuhide Yamamoto, Hirofumi Kawamoto, Ryo Terada, Tsuneyoshi Ogawa, Soichiro Nose

INTERNAL MEDICINE 48 ( 13 ) 1143 - 1147 2009

A case of mixed duct-islet cell tumor of the pancreas

IWAMURO Masaya, KUBOTA Junichi, SAITO Shunsuke, GOUBARU Motohiro, OHTA Takeyuki, OGATA Masatoshi, TAKUMA Yoshitaka, TANAKA Shouichi, MAKINO Yasuhiro, MURAKAMI Ichiro

Nippon Shokakibyo Gakkai Zasshi 104 ( 6 ) 829 - 836 2007.6

Language：Japanese Publisher：The Japanese Society of Gastroenterology

A 30-year-old woman was referred to us because of hypoglycemic attack. The tumor on the pancreatic body of 22 mm size was revealed by close inspection, and was diagnosed as insulinoma. Surgical resection was performed, but curative resection was impossible because the component of adenocarcinoma infiltrating into surrounding tissue coexisted with insulinoma. Postoperatively, we make a diagnosis of combined tumor of the pancreas, i.e. mixed duct-islet cell carcinoma. In this paper, we discuss this rare disorder and summarizie 33 cases reported in the Japanese literature.<br>

DOI： 10.11405/nisshoshi.104.829

CiNii Article

CiNii Books

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Other Link： http://search.jamas.or.jp/link/ui/2007273459

Gastric ulcer after prophylactic balloon-occluded retrograde transvenous obliteration. Reviewed

Takuma Y, Nouso K, Takayama H, Makino Y, Saito S, Tanaka S, Ogata M, Ohta T, Kubota J, Iwamuro M

Journal of gastroenterology 42 ( 3 ) 257 - 260 2007.3

Polypoid colonic hamartomatous inverted polyp Reviewed

Shouichi Tanaka, Masaya Iwamuro, Junichi Kubota, Motohiro Goubaru, Takeyuki Ohta, Masatoshi Ogata, Ichiro Murakam

DIGESTIVE ENDOSCOPY 19 ( 1 ) 40 - 42 2007.1

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