Preventive Effects of Fermented Brown Rice and Rice Bran on Spontaneous Lymphomagenesis in AKR/NSlc Female Mice

Fermented brown rice and rice bran with Aspergillus oryzae (FBRA) is known to possess potentials to prevent chemical carcinogenesis in multiple organs of rodents. In the present study, possible chemopreventive effect of FBRA against spontaneous occurrence of lymphomas was examined using female AKR/NSlc mice. Four-week-old female AKR/ NSlc mice were divided into three groups, and fed diets containing FBRA for 26 weeks at a dose level 0% (Group 1), 5% (Group 2) or 10% (Group 3). At the termination of experiment, the incidence of thymic malignant lymphoma of Group 3 was significantly lower than of Group 1 (p < 0.05). The average number of apoptotic cells of the thymic lymphoma of Group 3 was significantly larger than that of Group 1 (p < 0.05). In addition, the incidences of malignant lymphoma arising from body surface and abdominal lymph nodes, and the frequencies of lymphoma cell invasion to liver, kidney, spleen, and ovary of Group 3 were relatively lower than those of Group 1. These results indicate that FBRA inhibits spontaneous development of the lymphoma in female AKR/NSc mice and the inhibition of lymphomagenesis may relate to the induction of apoptosis by exposure of FBRA, suggesting that FBRA could be a protective agent against development of human lymphoma.

An Increased Chromosome 7 Copy Number in Endoscopic Bile Duct Biopsy Specimens Is Predictive of a Poor Prognosis in Cholangiocarcinoma.

BACKGROUND: The ability of fluorescence in situ hybridization (FISH) assays in endoscopic transpapillary bile duct biopsy specimens to predict the prognosis of cholangiocarcinoma (CCA) has not been elucidated. AIMS: We aimed to clarify the association between the results of UroVysion FISH assays and the prognosis of CCA. METHODS: We retrospectively reviewed 49 specimens obtained by transpapillary forceps biopsy from consecutive patients with CCA. The copy numbers of chromosomes 3, 7, and 17 were evaluated by FISH assay using UroVysion. We compared the overall survival (OS) of CCA patients with and without increased copy numbers of chromosomes 3, 7, and 17. Furthermore, we evaluated the association between OS and the clinicopathological parameters of CCA patients. RESULTS: The OS was significantly shorter in patients with than without an increased chromosome 7 copy number (log-rank p = 0.015; median OS 11.9 vs. 20.7 months). In the univariate analyses, age (p = 0.012), ECOG performance status (p = 0.046), tumor stage (p = 0.046), surgery (p = 0.006), and an increased chromosome 7 copy number (p = 0.017) were significantly associated with OS. The multivariate analysis revealed that an increased chromosome 7 copy number (hazard ratio, 2.46; 95% CI 1.15-5.27; p = 0.021) and advanced clinical stage (hazard ratio, 2.26; 95% CI 1.11-4.63; p = 0.025) were independently predictive of a poor OS. CONCLUSIONS: Detection by FISH assay of an increased chromosome 7 copy number in transpapillary forceps biopsy specimens is predictive of a poor prognosis in CCA patients.

Chemopreventive effects of angiotensin II receptor type 2 agonist on prostate carcinogenesis by the down-regulation of the androgen receptor.

We recently reported that angiotensin II receptor blockers (ARBs) have chemopreventive and chemotherapeutic potential against prostate cancer via the reduction of androgen receptor (AR) expression. In this study, we investigated the effects of the angiotensin II receptor type 2 (AT2R) agonist Compound 21 (C21), which is expected to play similar roles to an ARB, on prostate carcinogenesis using the transgenic rat for adenocarcinoma of prostate (TRAP) model previously established in our laboratory. In vitro analyses of the cell growth, Western blotting and reporter gene assays were performed using LNCaP cells. TRAP rats at 6 weeks of age were randomly divided into 3 groups of 12 animals each and treated with C21 at 1 or 2 mg/kg/day in drinking water for 12 weeks. C21 reduced the proliferation activity of prostate cancer cells and down-regulated the PSA promoter activity and the AR protein expression. We discovered that C21 inhibited the progression of prostate carcinogenesis in TRAP rats and decreased the incidence of adenocarcinoma in the lateral prostate. A significant increase in the apoptotic index with activation of caspase 3 and 7 were observed by immunohistochemistry and Western blotting analyses. C21 also down-regulated the expression of AR significantly in TRAP rat prostate. C21 decreased the expression of AR and reduced the proliferation activity effectively in prostate cancer cells and TRAP rat prostate. These findings suggest that AT2R agonist may be a candidate novel chemopreventive agent against human prostate cancer.

Differential diagnosis of cholangiocarcinoma and IgG4-related sclerosing cholangitis by fluorescence in situ hybridization using transpapillary forceps biopsy specimens.

BACKGROUND: Fluorescence in situ hybridization (FISH) of cytology specimens has been used to diagnose biliary strictures. However, the usefulness of FISH for differentiating between cholangiocarcinoma (CCA) and IgG4-related sclerosing cholangitis (IgG4-SC) has not been evaluated in forceps biopsy specimens. METHODS: We retrospectively reviewed 74 specimens obtained by transpapillary forceps biopsy between 2008 and 2015 from 49 consecutive patients with CCA and 25 with IgG4-SC. Specimens were considered positive for malignancy by FISH with UroVysion® if at least five cells exhibited polysomy (a gain of two or more in chromosomes 3, 7, or 17). RESULTS: A total of 27 (55.1%) patients with CCA, but none of the patients with IgG4-SC, were positive for malignancy by FISH. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FISH for the diagnosis of CCA were 55.1%, 100%, 100%, 53.2%, and 70.3%, respectively. The complementary use of FISH increased the sensitivity of hematoxylin-and-eosin (H&E) staining from 69.4% to 77.6%; the specificity was not reduced when either H&E or FISH was positive. CONCLUSIONS: The use of FISH in the analysis of forceps biopsy specimens might be one option to differentiate CCA from IgG4-SC.

The NADPH Oxidase Inhibitor Apocynin Suppresses Preneoplastic Liver Foci of Rats.

Reactive oxygen species (ROS) have been revealed to be important factors for carcinogenesis and tumor progression. Therefore, we focused on an ROS-generating protein, nicotinamide adenine dinucleotide phosphate oxidase, and evaluated whether its inhibitor, apocynin, could suppress hepatocarcinogenesis in a medium-term rat liver bioassay. The number and size of glutathione S-transferase placental form (GST-P)-positive foci were significantly reduced by apocynin in a dose-dependent manner. The reduction of ROS generation by apocynin was confirmed by dihydroethidium staining. Apocynin treatment also significantly reduced Ki-67 positivity, downregulated cyclooxygenase 2, and suppressed the activation of the c-Myc pathway. Meanwhile, ROS generation was not different between GST-P-positive foci and surrounding GST-P-negative areas of the liver. In conclusion, the present data suggest that apocynin possesses a potential antihepatocarcinogenic property.

Ectopic Gastric and Intestinal Phenotypes, Neuroendocrine Cell Differentiation, and SOX2 Expression Correlated With Early Tumor Progression in Colorectal Laterally Spreading Tumors.

INTRODUCTION: The significance of the ectopic gastric phenotype remains unclear in patients with colorectal laterally spreading tumors (LSTs). We investigated clinicopathologic differences among LST subtypes, aiming to identify factors indicative of malignant transformation and invasion that are linked to ectopic gastric phenotype and tumor progression. MATERIALS AND METHODS: We analyzed the morphologic characteristics of 105 colorectal LSTs resected by endoscopic submucosal dissection. LSTs were classified into 2 subtypes: granular (G-LST) and nongranular (NG-LST). Resected LSTs were analyzed histologically and were immunohistochemically stained for MUC5AC, MUC6, chromogranin A, CD10, and SOX2. RESULTS: The 105 LSTs included 60 G-LSTs and 45 NG-LSTs. By histology, G-LSTs comprised 5 adenomas with low-grade dysplasia (LAs), 45 adenomas with high-grade dysplasia (HAs), and 10 adenocarcinomas invading the submucosa (SMs). NG-LSTs comprised 8 LAs, 25 HAs, and 12 SMs. MUC5AC positivity was significantly higher in G-LSTs compared to NG-LSTs (P = .002), and MUC5AC positivity in HA lesions was significantly higher than in LA lesions (P = .01). MUC6 and SOX2 positivity in SM G-LSTs, and chromogranin A positivity in SM NG-LSTs were significantly higher than in HAs (P = .01, .01, and .03, respectively). CD10 positivity in SM NG-LSTs was significantly higher than in HAs and LAs (P = .02 and .01, respectively). CONCLUSION: Ectopic gastric and intestinal phenotypes, neuroendocrine cell differentiation, and SOX2 expression differ according to tumor grade in colorectal LSTs, and these markers are correlated with early tumor progression in each LST subtype.

Pioglitazone, a Peroxisome Proliferator-Activated Receptor γ Agonist, Suppresses Rat Prostate Carcinogenesis.

Pioglitazone (PGZ), a peroxisome proliferator-activated receptor γ agonist, which is known as a type 2 diabetes drug, inhibits cell proliferation in various cancer cell lines, including prostate carcinomas. This study focused on the effect of PGZ on prostate carcinogenesis using a transgenic rat for an adenocarcinoma of prostate (TRAP) model. Adenocarcinoma lesions as a percentage of overall lesions in the ventral prostate were significantly reduced by PGZ treatment in a dose-dependent manner. The number of adenocarcinomas per given area in the ventral prostate was also significantly reduced by PGZ treatment. The Ki67 labeling index in the ventral prostate was also significantly reduced by PGZ. Decreased cyclin D1 expression in addition to the inactivation of both p38 mitogen-activated protein kinase (MAPK) and nuclear factor (NF)κB were detected in PGZ-treated TRAP rat groups. In LNCaP, a human androgen-dependent prostate cancer cell line, PGZ also inhibited cyclin D1 expression and the activation of both p38 MAPK and NFκB. The suppression of cultured cell growth was mainly regulated by the NFκB pathway as detected using specific inhibitors in both LNCaP and PC3, a human androgen-independent prostate cancer cell line. These data suggest that PGZ possesses a chemopreventive potential for prostate cancer.

Preventive Effects of Fermented Brown Rice and Rice Bran against Prostate Carcinogenesis in TRAP Rats.

Fermented brown rice and rice bran with Aspergillus oryzae (FBRA) is considered to have the potential to prevent chemically-induced carcinogenesis in multiple organs of rodents. In the present study, we evaluated the possible chemopreventive effects of FBRA against prostate tumorigenesis. Six-week-old male rats of the transgenic rat for adenocarcinoma of prostate (TRAP) strain were fed diets containing 5% or 10% FBRA for 15 weeks. Animals were sacrificed at 21 weeks of age, and the ventral and lateral prostate were removed for histopathological evaluation and immunoblot analyses. FBRA decreased the incidence of adenocarcinoma in the lateral prostate and suppressed the progression of prostate carcinogenesis. Treatment with FBRA induced apoptosis and inhibited cell proliferation in histologically high-grade prostatic intraepithelial neoplasias. Phospho-AMP-activated kinase α (Thr172) was up-regulated in the prostate of rats fed the diet supplemented with FBRA. These results indicate that FBRA controls tumor growth by activating pathways responsive to energy deprivation and suggest that FBRA has translational potential for the prevention of human prostate cancer.

IgG4-related Sclerosing Cholangitis with No Biliary Stricture but Severe Thickening of the Bile Duct Wall.

We herein report a case of a 56-year-old man with IgG4-related sclerosing cholangitis (IgG4-SC) with no biliary stricture, but with a severely thickened bile duct wall. Contrast-enhanced computed tomography showed diffuse swelling of the pancreas and thickening of the common bile duct (CBD) wall with delayed enhancement. Obvious diffuse wall thickening of the CBD was observed on endoscopic ultrasonography. However, endoscopic retrograde cholangiography showed no biliary stricture in the CBD that had thickened. Although IgG4-SC has been classified by a stenotic lesion on cholangiography, we should be aware of some IgG4-SC cases showing only bile duct wall thickness without any biliary stricture.

SCF(Fbxo22)-KDM4A targets methylated p53 for degradation and regulates senescence.

Recent evidence has revealed that senescence induction requires fine-tuned activation of p53, however, mechanisms underlying the regulation of p53 activity during senescence have not as yet been clearly established. We demonstrate here that SCF(Fbxo22)-KDM4A is a senescence-associated E3 ligase targeting methylated p53 for degradation. We find that Fbxo22 is highly expressed in senescent cells in a p53-dependent manner, and that SCF(Fbxo22) ubiquitylated p53 and formed a complex with a lysine demethylase, KDM4A. Ectopic expression of a catalytic mutant of KDM4A stabilizes p53 and enhances p53 interaction with PHF20 in the presence of Fbxo22. SCF(Fbxo22)-KDM4A is required for the induction of p16 and senescence-associated secretory phenotypes during the late phase of senescence. Fbxo22(-/-) mice are almost half the size of Fbxo22(+/-) mice owing to the accumulation of p53. These results indicate that SCF(Fbxo22)-KDM4A is an E3 ubiquitin ligase that targets methylated p53 and regulates key senescent processes.

Connexin 32 dysfunction promotes ethanol-related hepatocarcinogenesis via activation of Dusp1-Erk axis.

There is abundant epidemiological evidence that heavy alcohol intake contributes to hepatocellular carcinoma (HCC) development. Previous reports indicated that connexin 32 (Cx32), which is a major hepatocyte gap junction protein, is down-regulated in chronic liver disease and has a protective role in hepatocarcinogenesis. However, functions of Cx32 in alcohol-related hepatocarcinogenesis have not been clarified. To evaluate them, 9-week-old Cx32 dominant negative transgenic (Tg) rats and their wild-type (Wt) littermates were given 1 % or 5 % ethanol (EtOH) or water ad libitum, for 16 weeks after an intraperitoneal injection of diethylnitrosamine (200 mg/kg). EtOH significantly increased the incidence and multiplicity of HCC and total tumors in a dose-dependent manner in Tg rats, but not in Wt rats. Although the number and area of glutathione S-transferase placental form (GST-P) positive foci were not significantly different between the groups, EtOH increased the Ki-67 labeling indices in GST-P positive foci only in Tg rats. EtOH up-regulated phosphorylated Erk1/2 with decrease of the Erk1/2 inhibitor, dual specificity protein phosphatase 1 (Dusp1) in whole livers of Tg and Wt rats. Immunofluorescence staining and quantitative RT-PCR revealed that EtOH significantly increased nucleolar localization of phosphorylated Erk1/2 and contrastingly reduced Dusp1 protein and mRNA expression in GST-P positive foci and HCC of Tg rats as compared to those of Wt rats. These findings suggest that Cx32 dysfunction like in chronic liver disease promoted EtOH-associated hepatocarcinogenesis through dysregulation of Erk-Dusp1 signaling.

Predictive factors for positive diagnosis of malignant biliary strictures by transpapillary brush cytology and forceps biopsy.

OBJECTIVE: The diagnostic yields of endoscopic transpapillary brush cytology and forceps biopsies for malignant biliary strictures (MBS) remain unclear and predictive factors for diagnosis have not been established. We aimed to clarify the diagnostic yields of both methods and the predictive factors METHODS: We reviewed 241 patients with biliary strictures who underwent transpapillary brush cytology (n = 202) or forceps biopsy (n= 208) between 2004 and 2014 at a single academic center. RESULTS: The sensitivity of forceps biopsy for MBS was significantly higher than that of brush cytology [60.6% (97/160) vs 36.1% (57/158), P < 0.01). The sensitivity of forceps biopsy was significantly higher in diagnosing bile duct cancer than pancreatic cancer [78.8% (52/66) vs 42.4% (28/66), P < 0.01). Multivariate analysis revealed that serum total bilirubin (TB) level (T-Bil) ≥ 4 mg/dL [odds ratio (OR) 2.506, 95% confidence interval (CI): 1.139-5.495, P = 0.022) was an independent predictor for positive diagnosis by brush cytology, while bile duct cancer (OR 4.926, 95% CI 2.183-11.111, P < 0.001), stricture length ≥ 30 mm (OR 2.941, 95% CI 1.119-7.752, P = 0.029) and TB ≥ 4 mg/dL (OR 2.252, 95% CI 1.052-4.831, P = 0.037) were significant indicators of a positive diagnosis by forceps biopsy. CONCLUSIONS: Endoscopic transpapillary forceps biopsy shows higher sensitivity than that of brush cytology for MBS. Bile duct cancer, stricture length ≥ 30 mm and TB ≥ 4 mg/dL are good indicators of forceps biopsy.

Chemopreventive effect of resveratrol and apocynin on pancreatic carcinogenesis via modulation of nuclear phosphorylated GSK3ß and ERK1/2.

Despite progress in clinical cancer medicine in multiple fields, the prognosis of pancreatic cancer has remained dismal. Recently, chemopreventive strategies using phytochemicals have gained considerable attention as an alternative in the management of cancer. The present study aimed to evaluate the chemopreventive effects of resveratrol (RV) and apocynin (AC) in N-Nitrosobis(2-oxopropyl)amine-induced pancreatic carcinogenesis in hamster. RV- and AC-treated hamsters showed significant reduction in the incidence of pancreatic cancer with a decrease in Ki-67 labeling index in dysplastic lesions. RV and AC suppressed cell proliferation of human and hamster pancreatic cancer cells by inhibiting the G1 phase of the cell cycle with cyclin D1 downregulation and inactivation of AKT-GSK3ß and ERK1/2 signaling. Further, decreased levels of GSK3ß(Ser9) and ERK1/2 phosphorylation and cyclin D1 expression in the nuclear fraction were observed in cells treated with RV or AC. Nuclear expression of phosphorylated GSK3ß(Ser9) was also decreased in dysplastic lesions and adenocarcinomas of hamsters treated with RV or AC in vivo. These results suggest that RV and AC reduce phosphorylated GSK3ß(Ser9) and ERK1/2 in the nucleus, resulting in inhibition of the AKT-GSK3ß and ERK1/2 signaling pathways and cell cycle arrest in vitro and in vivo. Taken together, the present study indicates that RV and AC have potential as chemopreventive agents for pancreatic cancer.

Connexin 32 and luteolin play protective roles in non-alcoholic steatohepatitis development and its related hepatocarcinogenesis in rats.

Non-alcoholic steatohepatitis (NASH) has the potential to lead to the development of cirrhosis and hepatocellular carcinoma (HCC). Connexin (Cx) 32, a hepatocyte gap-junction protein, plays a preventive role in hepatocarcinogenesis. However, the precise contribution of Cx32 in the development of NASH has not been established. In this study, we aimed to clarify the role of Cx32 and the chemopreventive effect of luteolin, an antioxidant flavonoid, on the progression of NASH and NASH-related hepatocarcinogenesis. Cx32 dominant negative transgenic (Cx32ΔTg) and wild-type (Wt) rats at 10 weeks of age were given diethylnitrosamine and fed methionine-choline-deficient diet (MCDD) or MCDD with luteolin for 12 weeks. MCDD induced steatohepatitis and fibrosis along with increased inflammatory cytokine expression and reactive oxygen species in the liver. These effects were more severe in Cx32ΔTg rats as compared with Wt rats, and significantly suppressed by luteolin in both genotypes. Concerning NASH-related hepatocarcinogenesis, the number of glutathione S-transferase placental form (GST-P)-positive foci was greater in Cx32ΔTg versus Wt rats, and significantly reduced by luteolin in Cx32ΔTg rats. Microarray analysis identified brain expressed, X-linked 1 (Bex1) as an upregulated gene in Cx32ΔTg rat liver. Quantitative RT-PCR and in situ hybridization revealed that increased Bex1 mRNA was localized in GST-P-positive foci in Cx32ΔTg rats, and the expression level was significantly decreased by luteolin. Moreover, Bex1 knockdown resulted in significant growth inhibition of the rat HCC cell lines. These results show that Cx32 and luteolin have suppressive roles in inflammation, fibrosis and hepatocarcinogenesis during NASH progression, suggesting a potential therapeutic application for NASH.

Inhibition of indoleamine 2,3-dioxygenase 1 expression alters immune response in colon tumor microenvironment in mice.

Indoleamine 2,3-dioxygenase (IDO), an enzyme that degrades the essential amino acid l-tryptophan along the kynurenine pathway, exerts immunomodulatory effects in a number of diseases. IDO expression is increased in tumor tissue and in draining lymph nodes; this increase is thought to play a role in tumor evasion by suppressing the immune response. A competitive inhibitor of IDO is currently being tested in clinical trials for the treatment of relapsed or refractory solid tumors, but the efficacy of IDO inhibition in colorectal tumors remains to be fully elucidated. In this study, we investigated the effect of IDO deficiency on colon tumorigenesis in mice by genetic deletion and pharmacological inhibition. Ido1-deficient((-/-)) mice were crossed with Apc(Min/+) mice or were administered azoxymethane with or without dextran sodium sulfate. Ido1 deficiency did not lead to significant differences in the size and number of colon tumors. Similarly, the pharmacological inhibition of IDO using 1-methyltryptophan (1-mT) also resulted in no significant differences in tumor size and number in Apc(Min/+) mice. However, Ido1 deficiency altered the immune response in the tumor microenvironment, showing a significant increase in mRNA expression of pro-inflammatory cytokines and a significant decrease in the number of Foxp3-positive regulatory T cells in the colon tumors of Ido1((-/-)) mice. Importantly, 1-mT treatment also significantly altered cytokine expression in the colon tumor tissues. These results suggest that IDO inhibition alone cannot sufficiently suppress colon cancer development in mice despite its immunomodulatory activity in the tumor microenvironment.

Establishment of a syngeneic orthotopic model of prostate cancer in immunocompetent rats.

We previously established 3 cell lines (PLS10, PLS20 and PLS30) from a chemically-induced prostate carcinoma in F344 rats, and demonstrated high potential for metastasis in nude mice. In the present study, we investigated the feasibility of establishing an orthotopic model using the 3 rat prostate cancer cell lines in immunocompetent rats with the aim of resolving species-mismatch problems and defects of immune systems. The PLS10, PLS20 and PLS30 cell lines were injected into the ventral prostates of 6-week-old rats, which were then sacrificed at experimental weeks 4 and 8. Tumor mass formation was found in rats with PLS10, but not in those with PLS20 or PLS30. Additionally, metastatic carcinomas could be detected in lymph nodes and lungs of PLS10-inoculated rats. Genetic analysis demonstrated K-ras gene mutations in PLS10 and PLS20, but not in PLS30 cells. There were no mutations in p53 and KLF6. In conclusion, we established a syngeneic orthotopic model for prostate cancer in immunocompetent rats simulating human castration-resistant prostate cancer (CRPC), which should prove useful for development and validation of therapeutic agents, especially with immunotherapy.

Reducing DNA methylation suppresses colon carcinogenesis by inducing tumor cell differentiation.

The forced reduction of global DNA methylation suppresses tumor development in several cancer models in vivo. Nevertheless, the mechanisms underlying these suppressive effects remain unclear. In this report, we describe our findings showing that a genome-wide reduction in the DNA methylation levels induces cellular differentiation in association with decreased cell proliferation in Apc (Min/+) mouse colon tumor cells in vivo. Colon tumor-specific DNA methylation at Cdx1 is reduced in the DNA-hypomethylated tumors accompanied by Cdx1 derepression and an increased expression of intestinal differentiation-related genes. Furthermore, a histological analysis revealed that Cdx1 derepression in the DNA-hypomethylated tumors is correlated with the differentiation of colon tumor cells. Similarly, the treatment of human colon cancer cell lines with a hypomethylating agent induces differentiation-related genes, including CDX1. We herein propose that DNA demethylation exerts a tumor suppressive effect in the colon by inducing tumor cell differentiation.

Ellagic acid, a component of pomegranate fruit juice, suppresses androgen-dependent prostate carcinogenesis via induction of apoptosis.

BACKGROUND: Ellagic acid (EA), a component of pomegranate fruit juice (PFJ), is a plant-derived polyphenol and has antioxidant properties. PFJ and EA have been reported to suppress various cancers, including prostate cancer. However, their chemopreventive effects on development and progression of prostate cancer using in vivo models have not been established yet. METHODS: The transgenic rat for adenocarcinoma of prostate (TRAP) model was used to investigate the modulating effects of PFJ and EA on prostate carcinogenesis. Three-week-old male transgenic rats were treated with EA or PFJ for 10 weeks. In vitro assays for cell growth, apoptosis, and Western blot were performed using the human prostate cancer cell lines, LNCaP (androgen-dependent), PC-3 and DU145 (androgen-independent). RESULTS: PFJ decreased the incidence of adenocarcinoma in lateral prostate, and both EA and PFJ suppressed the progression of prostate carcinogenesis and induced apoptosis by caspase 3 activation in the TRAP model. In addition, the level of lipid peroxidation in ventral prostate was significantly decreased by EA treatment. EA was able to inhibit cell proliferation of LNCaP, whereas this effect was not observed in PC-3 and DU145. As with the in vivo data, EA induced apoptosis in LNCaP by increasing Bax/Bcl-2 ratio and caspase 3 activation. Cell-cycle related proteins, p21(WAF) , p27(Kip) , cdk2, and cyclin E, were increased while cyclin D1 and cdk1 were decreased by EA treatment. CONCLUSIONS: The results indicate that PFJ and EA are potential chemopreventive agents for prostate cancer, and EA may be the active component of PFJ that exerts these anti-cancer effects.

Preventive effects of fermented brown rice and rice bran against N-nitrosobis (2-oxopropyl) amine-induced pancreatic tumorigenesis in male hamsters.

Fermented brown rice by Aspergillus oryzae (FBRA) is known to have the potential to prevent chemical carcinogenesis of the colon, liver, esophagus, urinary bladder, stomach and lungs in rodents. The present study examined the possible chemopreventive effects of FBRA on N-nitrosobis(2-oxopropyl)amine (BOP)-induced pancreatic tumorigenesis in hamsters. Five-week-old male Syrian golden hamsters were divided into seven groups. Groups 1-5 were subcutaneously injected with BOP (10 mg/kg body weight) four times during week 6 to induce pancreatic tumors, while groups 6 and 7 were injected with saline. Groups 2 and 3 were fed diets containing 5 and 10% FBRA, respectively, during the initiation phase. By contrast, groups 4 and 5 were fed diets containing 5 and 10% FBRA, respectively, during the post-initiation phase. Group 6 received a diet containing 10% FBRA throughout the experiment, and group 7 was kept on the basal diet alone and served as the untreated control. At the termination of the study (week 22), oral intake of 10% FBRA (group 5) during the post-initiation phase was identified to have significantly reduced the multiplicity (number of lesions/animal) of ductal adenocarcinoma [pancreatic intraepithelial neoplasia 3 (PanIN3); carcinoma in situ and invasive carcinoma] in comparison with group 1 control hamsters (0.24±0.44 vs. 0.71±0.72; P<0.05). Treatment with 10% FBRA in the post-initiation phase inhibited the progression of normal/precancerous lesions (PanIN1, mild hyperplastic lesions; and PanIN2, papillary hyperplasia) to ductal adenocarcinomas. Furthermore, dietary exposure to 10% FBRA during the initiation (group 3) and post-initiation phases (group 5) significantly reduced the multiplicity of PanIN2 (group 3, 0.55±0.69; group 5, 0.45±0.69; versus group 1, 1.26±1.24; P<0.05 and P<0.01, respectively). A significant reduction of Ki-67 positivity of PanIN2 in group 5 was also confirmed (group 5, 0.05±0.03; group 1, 0.22±0.12; P<0.01). Using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling, augmentation of apoptosis by FBRA exposure in the non-lesional ductal epithelium and proliferative lesions was not evident. These findings indicate that FBRA exhibits inhibitory effects on BOP-induced pancreatic tumorigenesis in hamsters due to the reduced proliferation rate of tumor cells. Thus, FBRA may be a promising chemopreventive agent in human pancreatic cancer.

The peroxisome proliferator-activated receptor (PPAR) α agonist fenofibrate suppresses chemically induced lung alveolar proliferative lesions in male obese hyperlipidemic mice.

Activation of peroxisome proliferator-activated receptor (PPAR) α disrupts growth-related activities in a variety of human cancers. This study was designed to determine whether fenofibrate, a PPARα agonist, can suppress 4-nitroquinoline 1-oxide (4-NQO)-induced proliferative lesions in the lung of obese hyperlipidemic mice. Male Tsumura Suzuki Obese Diabetic mice were subcutaneously injected with 4-NQO to induce lung proliferative lesions, including adenocarcinomas. They were then fed a diet containing 0.01% or 0.05% fenofibrate for 29 weeks, starting 1 week after 4-NQO administration. At week 30, the incidence and multiplicity (number of lesions/mouse) of pulmonary proliferative lesions were lower in mice treated with 4-NQO and both doses of fenofibrate compared with those in mice treated with 4-NQO alone. The incidence and multiplicity of lesions were significantly lower in mice treated with 4-NQO and 0.05% fenofibrate compared with those in mice treated with 4-NQO alone (p<0.05). Both doses of fenofibrate significantly reduced the proliferative activity of the lesions in 4-NQO-treated mice (p<0.05). Fenofibrate also significantly reduced the serum insulin and insulin-like growth factor (IGF)-1 levels, and decreased the immunohistochemical expression of IGF-1 receptor (IGF-1R), phosphorylated Akt, and phosphorylated Erk1/2 in lung adenocarcinomas. Our results indicate that fenofibrate can prevent the development of 4-NQO-induced proliferative lesions in the lung by modulating the insulin-IGF axis.