Masaya Kubota

Dr. Masaya Kubota


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
Open access
PDF file
TMToshihide Maeda
Toshihide Maeda
YSYohei Shirakami
Yohei Shirakami
DTDaisuke Taguchi
Daisuke Taguchi
TMTakao Miwa
Takao Miwa
MKMasaya Kubota
Masaya Kubota
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
Colorectal cancer represents one of the most serious complications of inflammatory bowel disease. The NLRP3 inflammasome plays a pivotal role in the onset and progression of inflammatory bowel disease and is also implicated in colorectal cancer. This study aimed to investigate whether NLRP3 deficiency or glyburide, a sulfonylurea used for diabetes management and known as an NLRP3 inhibitor, could suppress colitis and its related colorectal tumorigenesis. Mice were divided into three groups: a control group, a glyburide group, and an NLRP3-deficient group. We investigated acute colitis and inflammation-related tumor models using azoxymethane and dextran sodium sulfate. In the colitis model, the colonic inflammation grade was significantly increased in NLRP3-deficient mice but not in mice administered glyburide. In the colorectal carcinogenesis model, fewer colorectal tumors were observed in both NLRP3-deficient and glyburide-treated groups. Additionally, a reduction in the expression levels of inflammatory cytokine genes was detected in the colonic mucosa of the mice of these groups. These findings suggest that NLRP3 deficiency may exacerbate acute colitis, while pharmacological inhibition, as well as deficiency of NLRP3, suppresses colitis-related tumorigenesis, presumably due to the attenuation of chronic inflammation in the colorectum. Glyburide holds promise as a potential chemopreventive agent for colitis-related colorectal cancer.

1 August 2024 in Nutrients
Verified
Journal Article
Open access
PDF file
DTDaisuke Taguchi
Daisuke Taguchi
YSYohei Shirakami
Yohei Shirakami
HSHiroyasu Sakai
Hiroyasu Sakai
TMToshihide Maeda
Toshihide Maeda
TMTakao Miwa
Takao Miwa
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
More effective treatments for hepatitis viral infections have led to a reduction in the incidence of liver cirrhosis. A high-fat diet can lead to chronic hepatitis and liver fibrosis, but the effects of lipid intake on liver disease status, including hepatitis C virus and alcohol, after elimination of the cause are unclear. To investigate the effects, we used a rat cirrhosis model and a high-fat diet in this study. Male Wistar rats were administered carbon tetrachloride for 5 weeks. At 12 weeks of age, one group was sacrificed. The remaining rats were divided into four groups according to whether or not they were administered carbon tetrachloride for 5 weeks, and whether they were fed a high-fat diet or control diet. At 12 weeks of age, liver fibrosis became apparent and then improved in the groups where carbon tetrachloride was discontinued, while it worsened in the groups where carbon tetrachloride was continued. Liver fibrosis was notable in both the carbon tetrachloride discontinuation and continuation groups due to the administration of a high-fat diet. In addition, liver precancerous lesions were observed in all groups, and tumor size and multiplicity were higher in the high-fat diet-fed groups. The expression of genes related to inflammation and lipogenesis were upregulated in rats fed a high-fat diet compared to their controls. The results suggest that a high-fat diet worsens liver fibrosis and promotes liver carcinogenesis, presumably through enhanced inflammation and lipogenesis, even after eliminating the underlying cause of liver cirrhosis.

Verified
Journal Article
Open access
PDF file
YSYohei Shirakami
Yohei Shirakami
JKJunichi Kato
Junichi Kato
MOmasaya onishi
masaya onishi
DTDaisuke Taguchi
Daisuke Taguchi
TMToshihide Maeda
Toshihide Maeda
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
Cholangiocarcinoma is the second most common primary cancer of the liver and has a poor prognosis. Various animal models, including carcinogen-induced and genetically engineered rodent models, have been established to clarify the mechanisms underlying cholangiocarcinoma development. In the present study, we developed a novel mouse model of malignant lesions in the biliary ducts induced by the administration of the carcinogen azoxymethane to obese C57BLKS/J-db/db mice. A histopathological analysis revealed that the biliary tract lesions in the liver appeared to be an intrahepatic cholangiocarcinoma with higher tumor incidence, shorter experimental duration, and a markedly increased incidence in obese mice. Molecular markers analyzed using a microarray and a qPCR indicated that the cancerous lesions originated from the cholangiocytes and developed in the inflamed livers. These findings indicated that this is a novel mouse model of intrahepatic cholangiocarcinoma in the context of steatohepatitis. This model can be used to provide a better understanding of the pathogenic mechanisms of cholangiocarcinoma and to develop novel therapeutic strategies for this malignancy.

Verified
Journal Article
Open access
PDF file
DTDaisuke Taguchi
Daisuke Taguchi
YSYohei Shirakami
Yohei Shirakami
HSHiroyasu Sakai
Hiroyasu Sakai
DMDaisuke Minowa
Daisuke Minowa
TMTakao Miwa
Takao Miwa
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
Cholangiocarcinoma-associated mortality has been increasing over the past decade. The sodium-glucose cotransporter 2 inhibitor, canagliflozin, has demonstrated anti-tumor effects against several types of cancers; however, studies examining its potential impact on cholangiocarcinoma are lacking. This study investigated the anti-tumor effects of canagliflozin on cholangiocarcinoma and the effects of nicotinamide adenine dinucleotide (NAD)+ salvage pathway activation and sirtuin 1 on tumor growth. We evaluated cell proliferation and gene expression in several cholangiocarcinoma cell lines and analyzed the effects of canagliflozin on cell proliferation, apoptosis, and migration. Canagliflozin treatment decreased the viability of cholangiocarcinoma cells in a concentration-dependent manner but increased the viability at low concentrations in several cell lines. At high concentrations, canagliflozin arrested the cell cycle checkpoint in the G0/G1 phase. In contrast, at low concentrations, it increased the proportion of cells in the S phase. Canagliflozin also reduced the migratory ability of cholangiocarcinoma cells in a concentration-dependent manner. Canagliflozin treatment upregulated nicotinamide phosphoribosyltransferase (NAMPT), NAD+, and sirtuin 1 in cholangiocarcinoma and activated the NAD+ salvage pathway. The growth-inhibitory effect of canagliflozin was enhanced when combined with an NAMPT inhibitor. Canagliflozin inhibits cholangiocarcinoma cell growth and migration and its anti-tumor effect is enhanced when combined with an NAMPT inhibitor. However, further investigation is required because of its potential tumor growth-promoting effect through the activation of the NAD+ salvage pathway.

Verified
Journal Article
Open access
PDF file
KKKentaro Kojima
Kentaro Kojima
JTJun Takada
Jun Takada
KIKeisuke Iwata
Keisuke Iwata
KOKiichi Otani
Kiichi Otani
NMNaoya Masuda
Naoya Masuda
Masahito ShimizuMasahito Shimizu
Masahito Shimizu
Background/Objectives: Oral prednisolone (PSL) and budesonide multi-matrix (BUD-MMX) are used to induce remission in ulcerative colitis (UC); however, their therapeutic positioning remains unclear. Comparative data from real-world practices are limited. This study assessed the efficacy and safety of PSL and BUD-MMX in patients with active UC. Methods: Consecutive outpatients with UC initiated on oral PSL or BUD-MMX at two tertiary referral centers were included. The primary outcome was clinical remission at week 8, defined as a partial Mayo score (PMS) ≤ 1 with a rectal bleeding subscore of 0. Secondary outcomes included clinical response and safety. Pre-specified subgroup analyses were performed according to baseline disease activity. Results: Sixty PSL-treated and 40 BUD-MMX-treated patients were evaluated at week 8. Clinical remission was achieved in 65.0% and 55.0% of the PSL and BUD-MMX groups, respectively, whereas a clinical response was observed in 75.0% and 62.5%, respectively. No patient with a baseline PMS of 2–3 was initiated on PSL. Among patients with a baseline PMS of 4–5, the remission and response rates at week 8 were similar between the groups. In contrast, remission in patients with a baseline PMS ≥ 6 was numerically lower in the BUD-MMX group. Treatment escalation rates were comparable in the overall cohort, whereas adverse events were more frequent in the PSL group (23.3% vs. 2.4%). Conclusions: Treatment selection between PSL and BUD-MMX appeared to reflect baseline disease activity, with a partial overlap in the moderate clinical range. BUD-MMX may be a reasonable initial option for selected patients.

12 January 2026 in Clinical Nutrition ESPEN
Verified
Journal Article
Closed access
NMNaoya Masuda
Naoya Masuda
TMTakao Miwa
Takao Miwa
KNKayoko Nishimura
Kayoko Nishimura
YMYoshiyuki Miwa
Yoshiyuki Miwa
KKKentaro Kojima
Kentaro Kojima
Masahito ShimizuMasahito Shimizu
Masahito Shimizu