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ABSTRACT: We investigated the underlying mechanisms of L-leucine and L-isoleucine mediated promotion of bladder carcinogenesis using an initiation-promotion model. Rats were administered N-butyl-N-(4-hydroxybutyl) nitrosamine for 4 weeks and then fed AIN-93G basal diet or diet supplemented with L-leucine or L-isoleucine for 8 weeks followed by the basal diet for another 8 weeks. At the end of the experiment, week 20, there was a significant elevation of papillary and nodular (PN) hyperplasia multiplicity in the amino acid groups. L-Leucine and L-isoleucine transporters were up-regulated in PN hyperplasias and/or bladder tumors compared with concomitant normal-appearing bladder urothelium at weeks 12 and/or 20 in all groups. In addition, in normal-appearing bladder urothelium, significantly increased mRNA levels of y+LAT1, LAT2, LAT4, and 4F2hc were observed in the amino acid groups compared with the BBN control group at both weeks 12 and 20, and increased mRNA levels of LAT1 were observed at week 20. Furthermore, up-regulation of TNF-α, c-fos, β-catenin, p53, p21(Cip1/WAF1), cdk4, cyclin D1 and caspase 3 in the amino acid groups was detected in normal-appearing bladder urothelium. Overall, our results indicate that supplementation with L-leucine or L-isoleucine enhanced tumor growth of bladder urothelial tumors by triggering expression of amino acid transporters and tumorigenesis-associated genes.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 06/2013; · 2.99 Impact Factor
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ABSTRACT: Background: In a previous proteomic study, we detected increased expression of nephronectin in the glomeruli from patients with diabetic nephropathy (DN). The aim of the present study was to clarify the usefulness of determining glomerular expression of nephronectin in kidney disease. Methods: We performed immunohistochemical staining for nephronectin in renal biopsy specimens from patients with a variety of kidney diseases (n = 190). The percentage of nephronectin-positive areas in the glomeruli was analyzed using an image analyzer. Results: Nephronectin immunoreactivity was clearly, strongly positive in the mesangial expansion and nodular lesions of DN (n = 18), whereas nephronectin immunoreactivity was negative in IgA glomerulonephritis, membranoproliferative glomerulonephritis, lupus nephritis, membranous glomerulonephritis, minor glomerular abnormalities, crescentic glomerulonephritis, and other kidney diseases, such as amyloidosis and light chain deposition disease. Nephronectin was stained weakly in sclerotic lesions, such as focal segmental glomerulosclerosis and hypertensive nephropathy. The percentage of nephronectin-positive areas in the glomeruli from DN patients [15.1 ± 4.7% (n = 18)] was significantly higher than that for other kidney diseases [5.5 ± 3.6% (n = 172)] (p < 0.001). In multiple regression analyses, fasting plasma glucose and hemoglobin A1c were significantly associated with the increase in the percentage of nephronectin-positive areas in the glomeruli (β = 0.23, p < 0.001 and β = 0.16, p = 0.045, respectively). Conclusions: The expression of nephronectin was sufficient to discriminate DN from other kidney diseases with mesangial matrix expansion and nodular lesions. We consider that nephronectin staining could be helpful in the diagnosis of DN.
Nephron Clinical Practice 05/2013; 122(3-4):114-121. · 2.04 Impact Factor
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Setsuko Yabushita,
Katsumi Fukamachi,
Fumitake Kikuchi,
Masakazu Ozaki,
Kaori Miyata,
Tokuo Sukata,
Yoshihito Deguchi,
Hajime Tanaka,
Anna Kakehashi,
Satoshi Kawamura,
Satoshi Uwagawa, Hideki Wanibuchi,
Masumi Suzui,
David B Alexander,
Hiroyuki Tsuda
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ABSTRACT: OBJECTIVES: We have established rat models of pancreatic ductal adenocarcinoma (PDAC) in which expression of a human H-ras or K-ras oncogene regulated by the Cre/lox system drives pancreatic carcinogenesis. Pancreatic ductal adenocarcinoma, which develops in H-ras and K-ras transgenic rats is cytogenetically and histopathologically similar to human PDAC. The present study was designed to determine the feasibility of using the commercially available H-ras transgenic rat to find diagnostic protein biomarkers for human pancreatic cancer. METHODS: For an animal model to be useful for searching for protein biomarkers for a disease, it is essential that the proteins, which are up-regulated in the model, are also up-regulated in humans. We used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to compare H-ras transgenic rat PDAC with surrounding normal pancreas tissue. RESULTS: We identified 30 up-regulated proteins in the H-ras transgenic rat PDAC lesions; importantly, 21 human homologs of these 30 rat proteins are up-regulated in human pancreatic cancer patients. CONCLUSIONS: These results indicate that numerous proteins that are up-regulated in H-ras transgenic rat PDAC are also up-regulated in human pancreatic cancer; therefore, this rat model can be used to search for diagnostic biomarkers for this disease.
Pancreas 05/2013; · 2.39 Impact Factor
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ABSTRACT: We have previously reported that a specific siRNA transfected MUC5AC could knockdown MUC5AC expression and suppress in vivo tumor growth and metastasis, although it had no effects on in vitro cell growth, cell survival, proliferation and morphology. In the present study, we investigated which host immune cells induced these effects and how the effects were induced using immunocyte-depleted animal models. The tumor growth of SW1990/si-MUC5AC cells, which show no tumor growth when implanted subcutaneously into a nude mouse, was recovered when neutrophils were removed by anti-Gr-1 mAb administration. This result suggests that MUC5AC may suppress the antitumor effects of neutrophils by allowing tumor cells to escape the host immune system. Subsequently, we investigated the effects of MUC5AC on apoptosis induction mediated by TNF-related apoptosis-inducing ligand (TRAIL), one of the antitumor mechanisms of neutrophils. SW1990/si-MUC5AC cells showed significantly increased active caspase 3 expression after the addition of TRAIL. On the other hand, SW1990/si-mock cells showed no such changes. Our results indicate that MUC5AC inhibits TRAIL‑induced apoptosis in human pancreatic cancer and may serve as an important indicator in diagnosis and prognosis.
International Journal of Oncology 01/2013; · 2.40 Impact Factor
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ABSTRACT: The purposes of the present study were to evaluate the hepatocarcinogenicity of concurrent treatment of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and diethylnitrosamine (DEN) in rats and to determine whether no effect levels of combinations of these two different structural categories of genotoxic hepatocarcinogens exist. Two 16-week rat hepatocarcinogenesis assays were performed using a total of 790 male F344 rats. In experiment 1, we evaluated the effects of concurrent treatment of a subcarcinogenic dose of DEN on rat hepatocarcinogenesis induced by various doses of MeIQx. In experiment 2, we determined hepatocarcinogenicities of combinations of MeIQx and DEN at subcarcinogenic doses, low carcinogenic doses and high carcinogenic doses. Quantitative analyses of glutathione S-transferase placental form (GST-P)-positive foci, a preneoplastic lesion of the liver in rats, revealed that concurrent treatment with subcarcinogenic doses of DEN did not enhance MeIQx-induced rat hepatocarcinogenicity. We also found that concurrent treatment with combinations of subcarcinogenic doses of DEN and MeIQx was not hepatocarcinogenic, indicating that the combined effects of subcarcinogenic doses of DEN and MeIQx were neither additive nor synergistic. Moreover, concurrent treatment with low carcinogenic doses of these 2 carcinogens did not show additive or synergistic effects. Synergetic effects were observed only in rats coadministered high carcinogenic doses of the 2 carcinogens. These results demonstrate the existence of no effect levels of combinations of these 2 genotoxic hepatocarcinogens, and provide new evidence supporting our idea that there is a threshold, at least a practical threshold, that should be considered when evaluating the risk of genotoxic carcinogens. ( ; : -).
Journal of Toxicologic Pathology 09/2012; 25(3):209-14. · 0.48 Impact Factor
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ABSTRACT: In the present study, effects of l-leucine and l-isoleucine on rat bladder carcinogenesis were investigated using AIN-93G and MF basal diet. In Experiment 1, N-butyl-N-(4-hydroxybutyl)-nitrosamine was used as an initiator of bladder carcinogenesis. In the AIN-93G diet groups, a significantly higher incidence and multiplicity of bladder tumors, accompanied by decreased final body weight, was observed in the l-leucine-supplemented group and a significantly higher incidence of papillomas and total tumors was observed in the l-isoleucine-supplemented group. In the MF diet groups, the multiplicity of papillary and nodular hyperplasia was significantly increased in the l-isoleucine-supplemented group. Urinary pH values were not affected by supplementing either type of diet with l-leucine or l-isoleucine. In Experiment 2, the amino acid was administered in the basal diets for 2weeks without initiator. No pathological lesions were observed in the bladder urothelium in any of the groups, and no significant differences in urinary pH values, microcrystals or aggregates were observed between the amino acid-supplemented groups and their respective control groups. In conclusion, long-term treatment with l-leucine or l-isoleucine has a promoting effect on rat bladder carcinogenesis; therefore, their long-term use as a dietary supplement for bladder cancer patients should be avoided until more is known.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 08/2012; 50(11):3934-40. · 2.99 Impact Factor
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ABSTRACT: Dammar resin has long been used in foods as either a clouding or a glazing agent. In a recent study, 2% Dammar resin showed significant hepatocarcinogenicity in a rat 2-year bioassay. Therefore, for an accurate estimate of human risk, it is necessary to understand whether Dammar resin induces liver genotoxicity and the underlying mechanisms of its hepatocarcinogenicity. Modifying effects of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), a typical genotoxic carcinogen produced during cooking of protein-rich foods, was also studied in the present study. Exposure of gpt delta mice to Dammar resin at a dose of 2% for 12 weeks did not induce any obvious mutagenicity in the liver. However, the index of cell proliferation, the level of 8-OHdG, and bax, bcl-2, p53, cyp1a2, cyp2e1, gpx1 and gstm2 gene expression were all significantly increased when compared with the control group. In the IQ treatment group, at a dose of 300ppm, mutagenicity was readily detected, the index of cell proliferation increased, and p53, cyp2e1 and gpx1 gene expression was down-regulated in the liver. Down-regulation of p53, P450s, and gpx1 in the livers of IQ treated mice are consistent with its genotoxic mechanism of carcinogenicity observed in a 675-day study. In contrast, our results using gpt delta mice suggest that Dammar resin is not genotoxic. Instead, the Dammar resin-induced hepatocarcinogenicity seen in our previous 2-year study with rats may have been mediated by non-genotoxic mechanisms, including increased P450 enzyme activity, increased oxidative stress, altered gene expression, and promotion of cell proliferation.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 07/2012; 748(1-2):29-35. · 2.85 Impact Factor
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ABSTRACT: The present study aimed to identify useful candidate biomarkers of lung adenocarcinoma for clinical diagnosis and treatment using proteomics technology.
We assessed frequently highly overexpressed proteins in 12 cases of lung adenocarcinoma compared with adjacent normal tissue samples by liquid chromatography tandem mass spectrometry (LC-MS/MS) coupled with isobaric tags for relative and absolute quantitation (iTRAQ) technology, and validated the expression of target proteins by immunohistochemistry in 268 lung adenocarcinoma cases. Protein expression and clinicopathological variables were compared statistically for the evaluation of novel biomarkers.
One hundred seventy-seven proteins displaying significant quantitative changes compared with adjacent normal-appearing lung tissue were identified in more than 9 out of 12 lung adenocarcinoma patients. Based on the results of liquid chromatography tandem mass spectrometry, Ingenuity Pathway, and immunohistochemical analyses, anterior gradient homolog 2 (AGR2) (upregulated 9.9-fold) was selected as a potential biomarker of human lung adenocarcinoma. AGR2 was positive in 94% of lung adenocarcinoma patients. Negative AGR2 expression was associated with poor survival (p = 0.007).
AGR2 is likely to become a biomarker for clinical applications.
Osaka city medical journal 06/2012; 58(1):13-24.
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Yukie Kohata,
Yasuhiro Fujiwara,
Hirohisa Machida,
Hirotoshi Okazaki,
Hirokazu Yamagami,
Tetsuya Tanigawa,
Kenji Watanabe,
Toshio Watanabe,
Kazunari Tominaga,
Min Wei, Hideki Wanibuchi,
Tetsuo Arakawa
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ABSTRACT: BackgroundBarrett’s esophagus is characterized by a distinct Th-2-predominant cytokine profile, unlike the pro-inflammatory nature of
reflux esophagitis. The aim of this study was to examine the role of Th-2 cytokines during the development of Barrett’s esophagus,
using a rat model.
MethodsBarrett’s esophagus was induced by Levrat’s esophagojejunostomy technique in Brown-Norway (BN) rats. Rats were killed at 8,
15, 30, and 50weeks after the operation. We studied the incidences of esophagitis and Barrett’s esophagus, and the mRNA expression
of cytokines and CDX2 by real-time reverse transcriptase-polymerase chain reaction and immunohistochemical staining. Finally,
we compared the incidence of Barrett’s esophagus in BN rats with that in Sprague-Dawley (SD) rats.
ResultsEsophagitis was found in all rats. Barrett’s esophagus appeared 8weeks after the operation, and its incidence and length
increased over time. Levels of Th-2 cytokines such as interleukin (IL)-4, IL-10, and IL-13 were significantly increased in
Barrett’s esophagus as compared to those in non-Barrett’s esophagus, while there were no differences in the levels of pro-inflammatory
cytokines. The peak of elevated IL-4 mRNA was observed before that of CDX2 mRNA. IL-4 was co-localized in CD4-positive cells
and CDX2-positive goblet cells. The incidence of Barrett’s esophagus was more common in BN rats (8/10, 80%) than in SD rats
(2/7, 28%) at 30weeks.
ConclusionTh-2 cytokines, especially IL-4, may play a crucial role in the development of Barrett’s esophagus in an early phase. These
results provide understanding of the pathogenesis of Barrett’s esophagus from the aspect of the Th-2 immune response.
KeywordsBarrett’s esophagus–Th-2 cytokines–IL-4–CDX2–CD4
Journal of Gastroenterology 04/2012; 46(7):883-893. · 4.16 Impact Factor
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ABSTRACT: The object of the present study was to identify markers for predicting urinary bladder cancer progression by comparative proteome analysis of bladder cancers and paired normal mucosas. We found that DDX39 was overexpressed in four of six bladder cancers examined compared with respective control tissues. Immunohistochemical analysis using 303 bladder cancer specimens revealed that DDX39 was inversely correlated to pT stage and histological grade progression. The incidence of DDX39(high) tumors (positive cells ≥50%) was 68.6%, 43.5%, 20.0%, and 5.3% in pTa, pT1, pTis, and ≥pT2 tumors, respectively, and 65.2%, 60.7%, and 19.6% in G1, G2, and G3 tumors, respectively. The incidence of DDX39(high) tumors was significantly lower in pT1 and ≥pT2 compared to pTa tumors, and also significantly lower in G3 compared to G1 and G2 tumors. Follow-up analysis (n = 105) revealed that DDX39(low) tumors (positive cells <50%) were associated with disease progression (hazard ratio 7.485; P = 0.0083). Furthermore, DDX39-knockdown bladder cancer cells increased their invasion ability compared to negative control cells. These results suggest that DDX39 is a suppressor of invasion and loss of its function predicts disease progression in bladder cancers. (Cancer Sci, doi: 10.1111/j.1349-7006.2012.02298.x, 2012).
Cancer Science 04/2012; · 3.33 Impact Factor
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ABSTRACT: Our research is focused on modifying effects of an isoflavone aglycones (IAs)-rich extract at a hormonally active dose of 150 mg/kg body weight/day on mammary and endometrial carcinogenesis in female Donryu rats. IA administered for 2 weeks in a phytoestrogen-low diet exerted estrogenic activity and induced cell proliferation in the uterus of ovariectomized rats. Furthermore, administration for 4 weeks resulted in elevation of cell proliferation in the mammary glands of 7,12-dimethylbenz[a]anthracene (DMBA)-treated animals. Forty weeks of postpubertal administration of IA to 5-week-old rats after initiation of mammary and endometrial carcinogenesis with DMBA and N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) caused significant increase of incidence and multiplicity of mammary adenocarcinoma, multiplicities of endometrial atypical hyperplasia, adenomatous polyps, and an increased trend of uterine adenocarcinomas. Liquid chromatography with tandem mass spectrometry and immunohistochemical analyses revealed significant elevation of tumorigenesis-related proteins such as S100 calcium-binding protein A8, kininogen 1, and annexins 1 and 2 in mammary adenocarcinomas and cadherin EGF LAG seven-pass G-type receptor 2, DEAD box polypeptide 1, and cysteine- and glycine-rich protein 1 in uterine proliferative lesions of IA-treated animals. Those changes are likely to be related to modulation of estrogen receptor (ER), AP1, nuclear factor-kappa B, and actin signaling pathways. Our results indicate that the postpubertal exposure of Donryu rats to IA at an estrogenic dose results in promotion of mammary and uterine carcinogenesis induced by DMBA and ENNG, which might be related to the activation of ER-dependent signaling and alteration of the molecular tumor environment in the mammary gland and endometrium.
Toxicological Sciences 03/2012; 126(1):39-51. · 4.65 Impact Factor
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ABSTRACT: Pinocembrin (5, 7-dihydroxyflavanone) is a flavanone extracted from the rhizome of Boesenbergia pandurata. Our previous studies demonstrated that pinocembrin had no toxicity or mutagenicity in rats. We here evaluated its effects on the initiation and promotion stages in diethylnitrosamine-induced rat hepatocarcinogenesis, using short- and medium-term carcinogenicity tests. Micronucleated hepatocytes and liver glutathione-S-transferase placental form foci were used as end point markers. Pinocembrin was neither mutagenic nor carcinogenic in rat liver, and neither inhibited nor prevented micronucleus formation as well as GST-P positive foci formation induced by diethylnitrosamine. Interestingly, pinocembrin slightly increased the number of GST-P positive foci when given prior to diethylnitrosamine injection.
Asian Pacific journal of cancer prevention: APJCP 01/2012; 13(5):2257-61. · 0.66 Impact Factor
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ABSTRACT: To date, little proteomic information has been available from the glomeruli of diabetic patients, possibly due to the clinical limitations of renal biopsy in diabetic patients and insufficient quantities of such specimens for proteome analysis. The purpose of the present study was to identify altered protein expression profiles in diabetic glomeruli using formalin-fixed paraffin-embedded (FFPE) kidney tissues from diabetic patients.
Glomeruli were laser microdissected from FFPE autopsy kidney tissues from 10 patients with diabetic nephropathy and 10 non-diabetic control patients and underwent proteome analysis using QSTAR Elite liquid chromatography with tandem mass spectrometry and iTRAQ technology. Immunohistochemical analysis was performed on 93 autopsy samples from diabetic patients with and without nephropathy (n = 45 and n = 48, respectively).
Thirty-one renal and urological disease-related proteins displayed a differential abundance in glomerular samples from patients with diabetic nephropathy compared with non-diabetic control patients. Among them, we found that nephronectin, which functions in the assembly of extracellular matrix, showed clearly positive immunoreactivity in diabetic glomeruli. The numerical fraction of nephronectin-positive glomerular cross sections was increased significantly in diabetic patients with nephropathy compared to those without nephropathy (32.1 ± 31.5 versus 4.14 ± 5.65%, P < 0.0001). Furthermore, there was a significant positive correlation between this numerical fraction of nephronectin-positive glomerular cross sections and the glomerular sclerosis index (ρ = 0.881, P < 0.0001, n = 93).
The present study demonstrated, for the first time, that nephronectin may be associated with the development of diabetic glomerulosclerosis and that proteome analysis with FFPE kidney tissues from diabetic patients with nephropathy is useful in understanding diabetic nephropathy.
Nephrology Dialysis Transplantation 12/2011; 27(5):1889-97. · 3.40 Impact Factor
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ABSTRACT: The purposes of the present study were to investigate the modifying effects of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), a genotoxic carcinogen produced during cooking of protein-rich foods, and elucidate underlying mechanisms in a two-stage hepatocarcinogenesis mice model. Six-week-old B6C3F1 mice were subjected to two-thirds partial hepatectomy at the beginning of the study, followed by an intraperitoneal injection of diethylnitrosamine on day 1. Starting 1 week later, they were fed diets containing IQ at doses of 30, 100, or 300 ppm for 39 weeks. A dose-dependent trend for increase in eosinophilic altered foci as well as eosinophilic hepatocellular adenomas was observed, along with significant elevation in the incidence of hepatocellular carcinomas in the 100- and 300-ppm IQ groups as compared with initiation control group. Furthermore, IQ elevated the protein expression levels of Wnt1, transforming growth factor-β (TGF-β), TGF-β receptors 1 and 2 (TβR1 and TβR2), and phosphorylated c-Jun (p-c-Jun), while suppressing those of E-cadherin and p21(WAF1/Cip1). Moreover, translocation of β-catenin to the nuclei as well as upregulated nuclear expression of c-Myc and cyclin D1, which are downstream targets of β-catenin and p-c-Jun, were detected at 100 and 300 ppm. These findings suggest that IQ exerts dose-dependent promoting effects on mice hepatocarcinogenesis by activating TGF-β and Wnt/β-catenin signaling pathways and inhibiting cell adhesion.
Toxicological Sciences 11/2011; 125(2):392-400. · 4.65 Impact Factor
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Yukie Kohata,
Yasuhiro Fujiwara,
Hirohisa Machida,
Hirotoshi Okazaki,
Hirokazu Yamagami,
Tetsuya Tanigawa,
Kenji Watanabe,
Toshio Watanabe,
Kazunari Tominaga,
Min Wei, Hideki Wanibuchi,
Tetsuo Arakawa
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[hide abstract]
ABSTRACT: Barrett's esophagus is characterized by a distinct Th-2-predominant cytokine profile, unlike the pro-inflammatory nature of reflux esophagitis. The aim of this study was to examine the role of Th-2 cytokines during the development of Barrett's esophagus, using a rat model.
Barrett's esophagus was induced by Levrat's esophagojejunostomy technique in Brown-Norway (BN) rats. Rats were killed at 8, 15, 30, and 50 weeks after the operation. We studied the incidences of esophagitis and Barrett's esophagus, and the mRNA expression of cytokines and CDX2 by real-time reverse transcriptase-polymerase chain reaction and immunohistochemical staining. Finally, we compared the incidence of Barrett's esophagus in BN rats with that in Sprague-Dawley (SD) rats.
Esophagitis was found in all rats. Barrett's esophagus appeared 8 weeks after the operation, and its incidence and length increased over time. Levels of Th-2 cytokines such as interleukin (IL)-4, IL-10, and IL-13 were significantly increased in Barrett's esophagus as compared to those in non-Barrett's esophagus, while there were no differences in the levels of pro-inflammatory cytokines. The peak of elevated IL-4 mRNA was observed before that of CDX2 mRNA. IL-4 was co-localized in CD4-positive cells and CDX2-positive goblet cells. The incidence of Barrett's esophagus was more common in BN rats (8/10, 80%) than in SD rats (2/7, 28%) at 30 weeks.
Th-2 cytokines, especially IL-4, may play a crucial role in the development of Barrett's esophagus in an early phase. These results provide understanding of the pathogenesis of Barrett's esophagus from the aspect of the Th-2 immune response.
Journal of Gastroenterology 05/2011; 46(7):883-93. · 4.16 Impact Factor
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Hirotaka Hoshi,
Tetsuji Sawada,
Motoyuki Uchida,
Hikaru Saito,
Hiroko Iijima,
Mikako Toda-Agetsuma,
Tsutomu Wada,
Sadaaki Yamazoe,
Hiroaki Tanaka,
Kenjiro Kimura,
Anna Kakehashi,
Min Wei,
Kosei Hirakawa, Hideki Wanibuchi
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ABSTRACT: MUC5AC, a high molecular weight glycoprotein, is overexpressed in the ductal region of human pancreatic cancer but is not detectable in the normal pancreas, suggesting its association with disease development. In the present study, we investigated the in vitro and in vivo effects of MUC5AC knockdown by short interfering RNA (siRNA) in the MUC5AC-overexpressing SW1990 and BxPC3 human pancreatic cancer cell lines in order to clarify its function. Significant decreases in the expression levels of MUC5AC mRNA and protein were observed in SW1990 and BxPC3 cells that had been stably transfected with a MUC5AC siRNA expression vector (SW1990/si-MUC5AC and BxPC3/si-MUC5AC cells) compared to those in cells transfected with an si-mock vector (SW1990/si-mock and BxPC3/si-mock cells). In in vitro studies, neither type of MUC5AC-knockdown cell showed any difference in cell survival, proliferation, or morphology from the si-mock cells or parental cells. However, in vivo xenograft studies demonstrated that MUC5AC knockdown significantly reduced the tumorigenicity and suppressed the tumor growth of si-MUC5AC cells compared to those of the si-mock cells. Immunohistochemical analysis revealed that CD45R/B220+ and Gr-1+ cells had infiltrated into the tumor tissue of the SW1990/si-MUC5AC cells. Furthermore, cancer-associated antigen specific antibodies were detected at high levels in the sera from the SW1990/si-MUC5AC cell-bearing mice. These results suggest that tumor-associated MUC5AC expressed on the surface of pancreatic cancer cells supports the escape of pancreatic cancer cells from immunosurveillance. The present findings highlight a new dimension of MUC5AC as a functional immunosuppressive agent and its important role in pancreatic cancer progression.
International Journal of Oncology 03/2011; 38(3):619-27. · 2.40 Impact Factor
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ABSTRACT: In the present study, modifying effects of diabetes on carcinogenesis induced in type 2 diabetes mellitus model Zucker diabetic fatty (ZDF) rats were investigated using a multiorgan carcinogenesis bioassay. Our re sults demonstrated enhancement of urinary bladder, colon and liver carcinogenesis in ZDF rats treated with five types of carcinogens (DMBDD). Elevated insulin and leptin and decreased adiponectin levels in the serum may be responsible for the high susceptibility of type 2 diabetes mellitus model rats to carcinogenesis in these organs. Possible mechanisms of increased susceptibility of diabetic rats to bladder carcinogenesis could be activation of the PI3K pathway and suppression of p53 in the urothelium in consequence of the above serum protein alterations.
Journal of Toxicologic Pathology 03/2011; 24(1):25-36. · 0.48 Impact Factor
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ABSTRACT: Kojic acid (KA), a naturally occurring compound, is contained in traditional Japanese fermented foods and is used as a food additive, preservative and a dermatological skin-lightening agent. In the present experiment, initiation (experiment 1) and promotion (experiment 2) effects of KA-induced hepatocarcinogenesis were studied by rat medium-term bioassay for carcinogenicity. Male F344 rats were administered a diet containing 0-2% KA. Experiment 1 demonstrated that KA had no effect on induction of liver preneoplastic lesions or glutathione S-transferase placental form (GST-P) positive foci, in either number or area. In experiment 2, 2% KA treatment significantly increased the number and area of GST-P positive foci, but concentrations less than 0.5% did not. Moreover, 2% KA treatment significantly increased 8-OHdG levels and PCNA positive hepatocytes. The results indicated that low concentrations of KA do not have initiation effects on rat hepatocarcinogenesis, while higher concentrations of KA do promote hepatocarcinogenesis in rats. Thus, the results indicate that KA is a non-genotoxic hepatocarcinogen, showing the possible existence of a perfect threshold.
Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association 02/2011; 49(2):471-6. · 2.99 Impact Factor
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ABSTRACT: To evaluate proteins associated with the development of diabetic nephropathy, a major cause of the end-stage renal disease, we analyzed protein expression in isolated glomeruli from spontaneous type 2 diabetic (OLETF) rats and their age-matched control littermates (LETO) in the early and proteinuric stages of diabetic nephropathy using QSTAR Elite LC-MS/MS. Among the 191 and 218 proteins that were altered significantly in the OLETF rats, twenty-four were actin cytoskeleton-associated proteins implicated in the formation of stress fibers, and the impairment of actin polymerization, intermediate filaments and microtubules. Importantly, sorbin and SH3 domain containing 2 (SORBS2), which is involved in the formation of stress fibers, was significantly upregulated in both stages of diabetic nephropathy (1.49- and 1.97-fold, resp.). Immunohistochemical and quantitative-PCR analyses revealed upregulation of SORBS2 in podocytes of glomeruli of OLETF rats. Our findings suggested that SORBS2 may be associated with the development of diabetic nephropathy possibility by reorganization of actin filaments.
Experimental Diabetes Research 01/2011; 2011:979354. · 1.20 Impact Factor
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ABSTRACT: In the present study, the human orthologue of the secreted Xenopus laevis anterior gradient 2 (AGR2) protein was evaluated as a potential serum biomarker of lung adenocarcinoma. AGR2 protein levels were preoperatively measured in the serum of 111 primary lung adenocarcinoma patients and in 46 non-cancer controls with subsequent calculation of sensitivity and specificity in comparison with serum CEA levels. Correlations with clinicopathological variables were also assessed and survival analyses were performed according to the Kaplan-Meier method and differences determined with the log-rank test. The mean serum AGR2 level of lung adenocarcinoma patients in each stage, even Stage I, was significantly higher than in non-cancer controls (P < 0.001 for all stages, Mann-Whitney U test). The sensitivity was 65.8% (52.9% for stage IA), even higher than that of CEA, which was 45.0% (29.4% for stage IA), and the specificity was 87.0% according to the ROC curve (AUC=0.858). Positive serum AGR2 expression was significantly associated with the incidence of recurrence after surgery (P=0.025) and with a poor prognosis (P=0.037 for overall survival and P=0.004 for disease-free survival). Preoperative serum AGR2 might become a clinically useful biomarker for early detection, prediction of recurrence and prognosis with lung adenocarcinomas.
Cancer biomarkers: section A of Disease markers 01/2011; 10(2):101-7. · 1.08 Impact Factor
