Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
475
result(s) for
"Tanaka, Takuji"
Sort by:
Pathogenesis of Warthin’s Tumor: Neoplastic or Non-Neoplastic?
2024
Warthin’s tumor is the second most frequent neoplasm next to pleomorphic adenoma in the salivary gland, mostly in the parotid gland. The epithelial cells constituting a tumor are characterized by the presence of mitochondria that undergo structural and functional changes, resulting in the development of oncocytes. In addition to containing epithelial cells, Warthin’s tumors contain abundant lymphocytes with lymph follicles (germinal centers) that are surrounded by epithelial cells. The pathogenesis of Warthin’s tumor is not fully understood, and several hypotheses have been proposed. The risk factors for the development of Warthin’s tumor, which predominantly occurs in males, include aging, smoking, and radiation exposure. Recently, it has been reported that chronic inflammation and aging cells promote the growth of Warthin’s tumor. Several reports regarding the origin of the tumor have suggested that (1) Warthin’s tumor is an IgG4-related disease, (2) epithelial cells that compose Warthin’s tumor accumulate mitochondria, and (3) Warthin’s tumor is a metaplastic lesion in the lymph nodes. It is possible that the pathogenesis of Warthin’s tumor includes mitochondrial metabolic abnormalities, accumulation of aged cells, chronic inflammation, and senescence-associated secretory phenotype (SASP). In this short review, we propose that DNA damage, metabolic dysfunction of mitochondria, senescent cells, SASP, human papillomavirus, and IgG4 may be involved in the development of Warthin’s tumor.
Journal Article
Potential Chemopreventive Effects of Dietary Combination of Phytochemicals against Cancer Development
2023
Cancer remains a major cause of cancer-related death worldwide. Over 70% of epithelial malignancies are sporadic and are related to lifestyle. Epidemiological studies suggest an inverse correlation between cancer incidence and fruit and vegetable intake. Numerous preclinical studies using in vitro (cell lines) and in vivo animal models of oncogenesis have reported the chemopreventive effects of dietary phytochemical agents through alterations in different biomarkers and signaling pathways. However, there is contrasting evidence from preclinical studies and clinical trials. To date, the most studied compounds include curcumin, resveratrol, isoflavones, green tea extract (epigallocatechin gallate), black raspberry powder (anthocyanins and ellagitannins), bilberry extract (anthocyanins), ginger extract (gingerol derivatives), and pomegranate extract (ellagitannins and ellagic acid). Overall, the clinical evidence of the preventive effects of dietary phytochemicals against cancer development is still weak, and the amount of these phytochemicals needed to exert chemopreventive effects largely exceeds the common dietary doses. Therefore, we propose a combination treatment of natural compounds that are used clinically for another purpose in order to obtain excess inhibitory efficacy via low-dose administration and discuss the possible reasons behind the gap between preclinical research and clinical trials.
Journal Article
A novel inflammation-related mouse colon carcinogenesis model induced by azoxymethane and dextran sodium sulfate
by
MORI Hideki
,
SUGIE Shigeyuki
,
YAMADA Yasuhiro
in
Adenocarcinoma - chemically induced
,
Adenocarcinoma - metabolism
,
Adenocarcinoma - pathology
2003
To develop an efficient animal model for colitis‐related carcinogenesis, male Crj: CD‐1 (ICR) mice were given a single intraperitoneal administration (10 mg/kg body weight) of a genotoxic colonic carcinogen, azoxymethane (AOM), and a 1‐week oral exposure (2% in drinking water) to a non‐genotoxic carcinogen, dextran sodium sulfate (DSS), under various protocols. At week 20, colonic neoplasms (adenocarcinomas, 100% incidence with 5.60±2.42 multiplicity; and adenomas, 38% incidence with 0.20±0.40 multiplicity) with dysplastic lesions developed in mice treated with AOM followed by DSS. Protocols in which AOM was given during or after DSS administration induced a few tubular adenomas or no tumors in the colon. Immunohistochemical investigation of such dysplasias and neoplasms revealed that all lesions were positive for β‐catenin, cyclooxygenase‐2 and inducible nitric oxide synthase, but did not show p53 immunoreactivity. The results indicate that 1‐week administration of 2% DSS after initiation with a low dose of AOM exerts a powerful tumor‐promoting activity in colon carcinogenesis in male ICR mice, and may provide a novel mouse model for investigating colitis‐related colon carcinogenesis and for identifying xenobiotics with modifying effects.
Journal Article
Effect of Fermentation on the Protein Digestibility and Levels of Non-Nutritive Compounds of Pea Protein Concentrate
by
Tanaka, Takuji
,
Stone, Andrea K.
,
House, James D.
in
Amino acid composition
,
Amino acids
,
Bacteria
2018
In order to determine the impact of fermentation on protein quality, pea protein concentrate (PPC) was fermented with
for 11 h and total phenol and tannin contents, protease inhibitor activity, amino acid composition and
protein digestibility were analyzed. Phenol levels, expressed as catechin equivalents (CE), increased on dry mass basis from 2.5 at 0 h to 4.9 mg CE per 1 g of PPC at 11 h. Tannin content rose from 0.14 at 0 h to a maximum of 0.96 mg CE per 1 g of PPC after 5 h, and thereafter declined to 0.79 mg/g after 11 h. After 9 h of fermentation trypsin inhibitor activity decreased, however, at all other fermentation times similar levels to the PPC at time 0 h were produced. Chymotrypsin inhibitor activity decreased from 3.7 to 1.1 chymotrypsin inhibitory units (CIU) per mg following 11 h of fermentation. Protein digestibility reached a maximum (87.4%) after 5 h of fermentation, however, the sulfur amino acid score was reduced from 0.84 at 0 h to 0.66 at 11 h. This reduction in sulfur content altered the
protein digestibility-corrected amino acid score from 67.0% at 0 h to 54.6% at 11 h. These data suggest that while fermentation is a viable method of reducing certain non-nutritive compounds in pea protein concentrate, selection of an alternative bacterium which metabolises sulfur amino acids to a lesser extent than
should be considered.
Journal Article
Novel FXR agonist nelumal A suppresses colitis and inflammation-related colorectal carcinogenesis
2021
FXR is a member of the nuclear receptor superfamily and bile acids are endogenous ligands of FXR. FXR activation has recently been reported to inhibit intestinal inflammation and tumour development. This study aimed to investigate whether the novel FXR agonist nelumal A, the active compound of the plant
Ligularia nelumbifolia
, can prevent colitis and colorectal carcinogenesis. In a mouse colitis model, dextran sodium sulfate-induced colonic mucosal ulcer and the inflammation grade in the colon significantly reduced in mice fed diets containing nelumal A. In an azoxymethane/dextran sodium sulfate-induced mouse inflammation-related colorectal carcinogenesis model, the mice showed decreased incidence of colonic mucosal ulcers and adenocarcinomas in nelumal A-treated group. Administration of nelumal A also induced tight junctions, antioxidant enzymes, and FXR target gene expression in the intestine, while it decreased the gene expression of bile acid synthesis in the liver. These findings suggest that nelumal A effectively attenuates colonic inflammation and suppresses colitis-related carcinogenesis, presumably through reduction of bile acid synthesis and oxidative damage. This agent may be potentially useful for treatment of inflammatory bowel diseases as well as their related colorectal cancer chemoprevention.
Journal Article
p53 Expression as a Diagnostic Biomarker in Ulcerative Colitis-Associated Cancer
2017
Ulcerative colitis (UC) is defined as an idiopathic inflammatory disorder primarily involving the mucosa and submucosa of the colon. UC-associated colon cancers (also known as colitic cancers) develop through the inflammation–dysplasia sequence, which is a major problem affecting the prognosis of patients with UC. It is therefore very important to detect malignancy from UC at an early stage. As precancerous lesions arising in UC, there are pathological adenomatous changes, basal cell changes, in situ anaplasia, clear cell changes, and pan-cellular change. It is considered that the mutation of the p53 gene plays a crucial role, and the protein expression of p53 in dysplastic crypts may serve as a good biomarker in the early stages of UC-associated colon carcinogenesis. Immunohistochemistry for p53 is a very valuable diagnostic tool in UC-associated colon cancers. However, protein expression of p53 is not always universal, and additional methods may be required to assess p53 status in UC-associated colon cancers.
Journal Article
Virus-Driven Carcinogenesis
by
Tomita, Hiroyuki
,
Hatano, Yuichiro
,
Tanaka, Takuji
in
Acquired immune deficiency syndrome
,
AIDS
,
Carcinogenesis
2021
Cancer arises from the accumulation of genetic and epigenetic alterations. Even in the era of precision oncology, carcinogens contributing to neoplastic process are still an important focus of research. Comprehensive genomic analyses have revealed various combinations of base substitutions, referred to as the mutational signatures, in cancer. Each mutational signature is believed to arise from specific DNA damage and repair processes, including carcinogens. However, as a type of carcinogen, tumor viruses increase the cancer risk by alternative mechanisms, including insertional mutagenesis, viral oncogenes, and immunosuppression. In this review, we summarize virus-driven carcinogenesis to provide a framework for the control of malignant cell proliferation. We first provide a brief overview of oncogenic viruses and describe their implication in virus-related tumors. Next, we describe tumor viruses (HPV, Human papilloma virus; HBV, Hepatitis B virus; HCV, Hepatitis C virus; EBV, Epstein–Barr virus; Kaposi sarcoma herpesvirus; MCV, Merkel cell polyoma virus; HTLV-1, Human T-cell lymphotropic virus, type-1) and tumor virus-related cancers. Lastly, we introduce emerging tumor virus candidates, human cytomegalovirus (CMV), human herpesvirus-6 (HHV-6) and adeno-associated virus-2 (AAV-2). We expect this review to be a hub in a complex network of data for virus-associated carcinogenesis.
Journal Article
Pomegranate seed oil rich in conjugated linolenic acid suppresses chemically induced colon carcinogenesis in rats
by
YASUI Yumiko
,
MIYASHITA Kazuo
,
KOHNO Hiroyuki
in
Adenocarcinoma
,
Animals
,
Anticarcinogenic Agents - administration & dosage
2004
Pomegranate (Punica granatum L.) seed oil (PGO) contains more than 70% cis(c)9,frans(f)11,c13–18:3 as conjugated linolenic acids (CLN). Our previous short‐term experiment demonstrated that seed oil from bitter melon (Momordica charantia) (BMO), which is rich in c9,t11,t13‐CLN, inhibited the occurrence of colonic aberrant crypt foci (ACF) induced by azoxymethane (AOM). In this study, we investigated the effect of dietary PGO on the development of AOM‐induced colonic malignancies and compared it with that of conjugated linoleic acid (CLA). To induce colonic tumors, 6‐week old male F344 rats were given subcutaneous injections of AOM (20 mg/kg body weight) once a week for 2 weeks. One week before the AOM treatment they were started on diet containing 0.01%, 0.1%, or 1%±PGO or 1% CLA for 32 weeks. Upon termination of the bioassay (32 weeks) colon tumors were evaluated histopathologically. AOM exposure produced colonic adenocarcinoma with an incidence of 81% and multiplicity of 1.88±1.54 at week 32. Administration of PGO in the diet significantly inhibited the incidence (AOM+0.01% PGO, 44%, P<0.05; AOM+0.1% PGO, 38%, P<0.01; AOM+1% PGO, 56%) and the multiplicity (AOM+0.01% PGO, 0.56±0.73, P<0<01; AOM+0.1% PGO, 0.50±0.73, P<0.005; AOM+1% PGO, 0.88±0.96, P<0.05) of colonic adenocarcinomas, although a clear dose‐response relationship was not observed at these dose levels. CLA feeding also slightly, but not significantly, reduced the incidence and multiplicity of colonic adenocarcinomas. The inhibition of colonic tumors by PGO was associated with an increased content of CLA (c9,t11–18:2) in the lipid fraction of colonic mucosa and liver. Also, administration of PGO in the diet elevated expression of peroxisome proliferator activated receptor (PPAR) γ protein in the nontumor mucosa. These results suggest that PGO rich in c9,t11,c13‐CLN can suppress AOM‐induced colon carcinogenesis, and the inhibition is associated in part with the increased content of CLA in the colon and liver and/or increased expression of PPARγ protein in the colon mucosa.
Journal Article
Fucoxanthin and Colorectal Cancer Prevention
2021
Colorectal cancer (CRC), which ranks among the top 10 most prevalent cancers, can obtain a good outcome with appropriate surgery and/or chemotherapy. However, the global numbers of both new cancer cases and death from CRC are expected to increase up to 2030. Diet-induced lifestyle modification is suggested to be effective in reducing the risk of human CRC; therefore, interventional studies using diets or diet-derived compounds have been conducted to explore the prevention of CRC. Fucoxanthin (Fx), a dietary carotenoid, is predominantly contained in edible brown algae, such as Undaria pinnatifida (wakame) and Himanthalia elongata (Sea spaghetti), which are consumed particularly frequently in Asian countries but also in some Western countries. Fx is responsible for a majority of the anticancer effects exerted by the lipophilic bioactive compounds in those algae. Interventional human trials have shown that Fx and brown algae mitigate certain risk factors for CRC; however, the direct mechanisms underlying the anti-CRC properties of Fx remain elusive. Fx and its deacetylated type “fucoxanthinol” (FxOH) have been reported to exert potential anticancer effects in preclinical cancer models through the suppression of many cancer-related signal pathways and the tumor microenvironment or alteration of the gut microbiota. We herein review the most recent studies on Fx as a potential candidate drug for CRC prevention.
Journal Article
Development of redox potential-driven fermentation process for recombinant protein expression
2021
ObjectivesA redox potential-driven fermentation, maintaining dissolved oxygen at a prescribed level while simultaneously monitoring the changes of fermentation redox potential, was developed to guide the cultivation progress of recombinant protein expression.ResultsA recombinant E. coli harboring prolinase-expressing plasmid (pKK-PepR2) was cultivated using the developed process. Two distinct ORP valleys were noticeable based on recorded profile. The first ORP valley is equivalent to the timing for the addition of inducing agent, and the second ORP valley serves to guide the timing for cell harvesting. The final prolinase activity is 0.172 μmol/mg/min as compared to that of 0.154 μmol/mg/min where the optical density was employed to guide the timing of inducer addition and an empirically determined length of the cultivation.ConclusionThe developed process can be further modified to become an automatic operation.
Journal Article