Hypoxia-inducible factor-2 alpha up-regulates CD70 under hypoxia and enhances anchorage-independent growth and aggressiveness in cancer cells Hypoxia-inducible factor-2 alpha up-regulates CD70 under hypoxia and enhances anchorage-independent growth and aggressiveness in cancer cells

To uncover mechanisms and explore novel biomarkers of obesity, type 2 diabetes (T2DM) and nonalcoholic steatohepatitis (NASH)-associated hepatocarcinogenesis, cellular and molecular alterations in the liver, and hepatocellular carcinomas (HCCs) were investigated in NASH model 60-week-old Tsumura, Suzuki, Obese Diabetic (TSOD) mice and NASH HCC patients. Markedly elevated lipid deposition, inflammation, fibrosis, and peroxisome proliferation in the liver, preneoplastic lesions, and HCCs of TSOD mice were accompanied by accumulation of polysaccharides in the cellular cytoplasm and nuclei and increase of oxidative DNA damage marker, 8-hydroxydeoxyguanosine (8-OHdG) formation in the liver and altered foci. Metabolomics of TSOD mice HCCs demonstrated significant elevation of the concentration of amino acid L-arginine, phosphocreatine, S-adenosylmethionine/S-adenosylhomocysteine ratio, adenylate, and guanylate energy charges in coordination with tremendous rise of glucose metabolites, mostly fructose 1,6-diphosphate. L-arginine accumulation in HCCs was associated with significant under-expression of arginase 1 (ARG1), suppression of the urea cycle, methionine and putrescine degradation pathways, activation of Ser and Thr kinase Akt AKT, phosphoinositide 3-kinase (PI3K), extracellular signal-regulated kinase 1/2 (ERK1/2) kinases, β-catenin, mammalian target of rapamycin (mTOR), and cell proliferation. Furthermore, clinicopathological analysis in 20 metabolic syndrome/NASH and 80 HCV-positive HCC patients demonstrated significant correlation of negative ARG1 expression with poor tumor differentiation, higher pathological stage, and significant decrease of survival in metabolic syndrome/NASH-associated HCC patients, thus indicating that ARG1 could become a potential marker for NASH HCC. From these results, formation of oxidative stress and 8-OHdG in the DNA and elevation of glucose metabolites and L-arginine due to ARG1 suppression in mice liver cells are the important characteristics of T2DM/NASH-associated hepatocarcinogenesis, which may take part in activating oxidative stress resistance, synthesis of phosphocreatine, cell signaling, methylation, and proliferation.

The role of cells expressing stem cell markers deltaNp63 and CD44v has not yet been elucidated in peripheral‐type lung squamous cell carcinoma (pLSCC) carcinogenesis. Female A/J mice were painted topically with N‐nitroso‐tris‐chloroethylurea (NTCU) for induction of pLSCC, and the histopathological and molecular characteristics of NTCU‐induced lung lesions were examined. Histopathologically, we found atypical bronchiolar hyperplasia, squamous metaplasia, squamous dysplasia, and pLSCCs in the treated mice. Furthermore, we identified deltaNp63^posCD44v^posCK5/6^posCC10^pos clara cells as key constituents of early precancerous atypical bronchiolar hyperplasia. In addition, deltaNp63^posCD44v^pos cells existed throughout the atypical bronchiolar hyperplasias, squamous metaplasias, squamous dysplasias, and pLSCCs. Overall, our findings suggest that NTCU induces pLSCC through an atypical bronchiolar hyperplasia–metaplasia–dysplasia–SCC sequence in mouse lung bronchioles. Notably, Ki67‐positive deltaNp63^posCD44v^pos cancer cells, cancer cells overexpressing phosphorylated epidermal growth factor receptor and signal transducer and activator of transcription 3, and tumor‐associated macrophages were all present in far greater numbers in the peripheral area of the pLSCCs compared with the central area. These findings suggest that deltaNp63^posCD44v^pos clara cells in mouse lung bronchioles might be the origin of the NTCU‐induced pLSCCs. Our findings also suggest that tumor‐associated macrophages may contribute to creating a tumor microenvironment in the peripheral area of pLSCCs that allows deltaNp63^posCD44v^pos cancer cell expansion through activation of epidermal growth factor receptor signaling, and that exerts an immunosuppressive effect through activation of signal transducer and activator of transcription 3 signaling.

Background/Aim: Propolis has since long been utilized in numerous folk medicines with a variety of medicinal properties. In this study, the effects of ethanol-extracted (EEP) and water-extracted (WEP) Brazilian green propolis on the post-initiation phase of inflammation-associated rat colon tumorigenesis were directly compared. Materials and Methods: Male F344 rats at 6 weeks of age were subcutaneously injected with 1,2-dimethylhydrazine (DMH) at 40 mg/kg body weight twice during the first week, followed by 1% dextran sodium sulfate (DSS) in drinking water for one week. After a 1-week no-treatment period, animals were administered either basal Oriental MF powdered diet, or 1% EEP or 1% WEP in the basal diet until week 32. Results: Post-initiation treatment with EEP significantly reduced the multiplicity of colorectal carcinomas compared to the control (0.40±0.13/rat vs. 2.29±0.84/rat, respectively, p<0.05), and EEP also reduced the tumor volume. Immunohistochemically, expression of inflammation-associated proteins inducible nitric oxide synthase, tumor necrotic factor alpha, nuclear factor kappa B and glutathione peroxidase-2 were significantly diminished in colorectal tumors from EEP-treated rats. Conclusion: Suppression of inflammation and oxidative stress, which had been triggered by DMH and promoted by DSS, was a primary mechanism by which EEP suppressed carcinogenesis.

The present study was conducted over a course of 104 weeks to estimate the carcinogenicity of ethanol-extracted Brazilian green propolis (EEP). Groups of 50 male and 50 female Wistar Hannover rats, 6-week-old at commencement were exposed to EEP at doses of 0, 0.5 or 2.5% in the diet. Survival rates of 0.5% and 2.5% EEP-treated male and female rats, respectively, were significantly higher than those of respective control groups. Overall histopathological evaluation of neoplasms in rat tissues after 2 years showed no significant increase of tumors or preneoplastic lesions in any organ of animals administered EEP. Significantly lower incidences of pituitary tumors in 0.5% EEP male and 2.5% EEP female groups, malignant lymphoma/leukemia in both 2.5% EEP-treated males and females and total thyroid tumors in 0.5% EEP male group were found. Administration of EEP caused significant decreases of lymphoid hyperplasia of the thymus and lymph nodes in 2.5% EEP-treated rats, tubular cell hyperplasia of kidneys in all EEP groups, and cortical hyperplasia of adrenals in EEP-treated females. In the blood, significant reduction of neutrophils in all EEP-treated males and band neutrophils in 2.5% EEP-treated females was found indicating lower levels of inflammation. Total cholesterol and triglicerides levels were significantly lower in the blood of 2.5% EEP-treated female rats. In conclusion, under the conditions of the 2-year feeding experiment, EEP was not carcinogenic, did not induce significant histopathological changes in any organ, and further exerted anti-inflammatory and antitumorigenic effects resulting in increase of survival of Wistar Hannover rats.

Rat bladder cancer is nearly always papillary non‐invasive urothelial carcinoma (UC). To establish an animal model mimicking invasive UC that arises from papillary non‐invasive UC in the bladder, male human c‐Ha‐ras proto‐oncogene transgenic rats (Hras128) were treated with 0.05% N‐butyl‐N‐(hydroxybutyl)nitrosameine (BBN) in their drinking water and/or 0.1% phenylethyl isothiocyanate (PEITC) in their diet as follows: BBN (8 weeks)→PEITC (8 weeks); PEITC (8 weeks)→BBN (8 weeks); BBN alone (16 weeks); PEITC alone (16 weeks); and no treatment. At the end of week 16, the highest incidence of invasive UC was observed in the BBN→PEITC group. Therefore, we used Hras128 rats treated with BBN followed by PEITC as a model of invasive bladder cancer to identify invasion‐associated proteins. Proteome analysis was performed to compare the protein profiles of invasive and non‐invasive UC in Hras128 rats. We identified 49 proteins that were either overexpressed or underexpressed in invasive UC but not in non‐invasive UC. Immunohistochemical analysis of carbonic anhydrase 2 (CA2), an overexpressed protein, showed that the relative number of CA2‐positive UC was significantly higher for invasive UC compared to non‐invasive UC in rats. Moreover, the incidence of CA2‐positive cancers was also significantly higher for human muscle‐invasive bladder cancer (MIBC) compared to non‐MIBC (NMIBC) and was positively associated with the progression of NMIBC. Our findings indicate that CA2 is an invasion‐associated factor and suggest that it could serve as a potential therapeutic molecular target for bladder cancers.