Reversible acetylation modulates p54nrb/NONO-mediated expression of the interleukin 8 gene.

The non-POU domain-containing octamer-binding protein (NONO, also referred to as p54nrb) is a multifunctional nuclear protein engaging in transcriptional regulation, mRNA splicing, nuclear retention of defective RNA, and DNA repair. Emerging evidence has demonstrated that p54nrb is subjected to various posttranslational modifications, including phosphorylation and methylation, which may be important regulators of its multifunction. However, among these modifications, direct evidence of p54nrb acetylation and its underlying mechanism remains unclear. In this study, we reported that lysine 371 of p54nrb was reversibly acetylated by the acetyltransferase general control non-depressible 5 (GCN5) and deacetylase sirtuin 1 (SIRT1), which was crucial for activity of p54nrb to inhibit interleukin-8 (IL-8) expression. Mechanistically, GCN5-mediated acetylation attenuates the recruitment of p54nrb on its core binding motif within the IL-8 gene promoter, preferentially increasing the expression of the IL-8 gene. In contrast, deacetylation by SIRT1 reverses this process. Altogether, our data suggest that reversible acetylation is an important switch for the multiple nuclear functions of p54nrb/NONO.

How Do Patients Value the Benefit of Minimally Invasive Surgery in Cancer Treatment?

OBJECTIVES: Due to the increasing cost of cancer treatment, the demand for value-based healthcare is increasing. Although several value frameworks have been developed recently in the field of oncology, the nononcological benefits of minimally invasive surgery have not been addressed. This study aimed to estimate how patients value nononcological benefits in minimally invasive cancer surgery. METHODS: The value that patients placed on various benefits of cancer surgery was termed throughout the study as patient value (PV). To quantize PVs for the benefits of cancer surgery, a one-tiered analytic hierarchy process model was constructed. The model includes 6 well-known surgical outcomes, including nononcological benefits. The study participants included 303 patients with cancer and family caregivers who participated in a questionnaire survey. RESULTS: The PVs for "decreased operation time," "reduced length of hospital stay," and "improved cosmetic results" were 0.050, 0.044, and 0.045, respectively, whereas the PVs for "increased survival," "prevention of disease recurrence," and "avoidance of complications" were 0.366, 0.292, and 0.203, respectively. The PV placed on nononcological benefits from minimally invasive surgery was one-tenth (10.2%) of the total value. CONCLUSIONS: Nononcological benefits arising from minimally invasive surgery were relatively small but nonnegligible. This value should be considered in the process of developing a value framework for cancer surgery and shared decision making.

Naa20, the catalytic subunit of NatB complex, contributes to hepatocellular carcinoma by regulating the LKB1-AMPK-mTOR axis.

N-α-acetyltransferase 20 (Naa20), which is a catalytic subunit of the N-terminal acetyltransferase B (NatB) complex, has recently been reported to be implicated in hepatocellular carcinoma (HCC) progression and autophagy, but the underlying mechanism remains unclear. Here, we report that based on bioinformatic analysis of Gene Expression Omnibus and The Cancer Genome Atlas data sets, Naa20 expression is much higher in HCC tumors than in normal tissues, promoting oncogenic properties in HCC cells. Mechanistically, Naa20 inhibits the activity of AMP-activated protein kinase (AMPK) to promote the mammalian target of rapamycin signaling pathway, which contributes to cell proliferation, as well as autophagy, through its N-terminal acetyltransferase (NAT) activity. We further show that liver kinase B1 (LKB1), a major regulator of AMPK activity, can be N-terminally acetylated by NatB in vitro, but also probably by NatB and/or other members of the NAT family in vivo, which may have a negative effect on AMPK activity through downregulation of LKB1 phosphorylation at S428. Indeed, p-LKB1 (S428) and p-AMPK levels are enhanced in Naa20-deficient cells, as well as in cells expressing the nonacetylated LKB1-MPE mutant; moreover, importantly, LKB1 deficiency reverses the molecular and cellular events driven by Naa20 knockdown. Taken together, our findings suggest that N-terminal acetylation of LKB1 by Naa20 may inhibit the LKB1-AMPK signaling pathway, which contributes to tumorigenesis and autophagy in HCC.

Subretinal transplantation of human embryonic stem cell-derived retinal pigment epithelium (MA09-hRPE): A safety and tolerability evaluation in minipigs.

This study aimed to determine the safety and tolerability of the subretinal injection of hESC-derived RPE cells at higher doses than the established clinical dose (5 × 104 cells/150 µL) by using minipigs. The hESC-derived RPE cells (60 or 120 × 104 cells/150 µL) were injected in subretinal region, and minipigs were sacrificed at Weeks 4, 8, and 12 post-surgery. Time-course examination was performed by using fundus photography, optical coherence tomography (OCT), histopathology, and fluorescence in situ hybridization (FISH). After surgery, retinal bleb and pigmentation were seen and retinal bleb became smaller gradually. In histopathology, cell clusters consisting of a uniform population of the round to oval cells were seen at the subretinal injection site. In immunohistochemistry, most of the cells were positive for anti-CD3 and CD45 antibodies but negative for anti-human nuclei antibody; transplanted cells were not detectable by DNA probe in FISH assay. Cell clusters were thought to be a host immune response to trauma or transplanted cells. There were no other changes related to subretinal RPE cell injection. These results suggested that subretinal injection of hESC-derived RPE cells (60 and 120 × 104 cells/150 µL) in minipigs is well-tolerated and safe.

Multiple recombination events between two cytochrome P450 loci contribute to global pyrethroid resistance in Helicoverpa armigera.

The cotton bollworm, Helicoverpa armigera (Hübner) is one of the most serious insect pest species to evolve resistance against many insecticides from different chemical classes. This species has evolved resistance to the pyrethroid insecticides across its native range and is becoming a truly global pest after establishing in South America and having been recently recorded in North America. A chimeric cytochrome P450 gene, CYP337B3, has been identified as a resistance mechanism for resistance to fenvalerate and cypermethrin. Here we show that this resistance mechanism is common around the world with at least eight different alleles. It is present in South America and has probably introgressed into its closely related native sibling species, Helicoverpa zea. The different alleles of CYP337B3 are likely to have arisen independently in different geographic locations from selection on existing diversity. The alleles found in Brazil are those most commonly found in Asia, suggesting a potential origin for the incursion of H. armigera into the Americas.

Significance of EZH2 expression in canine mammary tumors.

BACKGROUND: Current studies report that aberrations in epigenetic regulators or chromatin modifications are related to tumor development and maintenance. EZH2 (Enhancer of zeste homolog 2) is one of the catalytic subunits of Polycomb repressive complex 2, a crucial epigenetic regulator. EZH2 has a master regulatory function in such processes as cell proliferation, stem cell differentiation, and early embryogenesis. In humans, EZH2 is linked to oncogenic function in several carcinomas, including breast cancer, and dysregulation of EZH2 has been particularly associated with loss of differentiation and the development of poorly differentiated breast cancer. In our present study, we were interested in determining whether EZH2 is increased in canine mammary tumors, which show similarities to human breast cancer. RESULTS: Investigation of the expression of EZH2 in canine mammary tumors revealed that EZH2 protein was overexpressed in canine mammary carcinomas, as in human breast cancer. In addition, the immunohistochemical expression level of EZH2 was associated with the degree of malignancy in canine mammary carcinoma. This is the first report to describe EZH2 expression in canine mammary tumors. CONCLUSIONS: Because the expression of EZH2 was similar in canine mammary carcinoma and human breast cancer, spontaneous canine mammary tumors may be a suitable model for studying EZH2 and treatment development.

Time-course changes in the expression levels of miR-122, -155, and -21 as markers of liver cell damage, inflammation, and regeneration in acetaminophen-induced liver injury in rats.

Drug-induced liver injury (DILI) is a significant threat to patient health and a major concern during drug development. Recently, multiple circulating microRNAs (miRNAs) have been reported to be potential biomarkers for DILI. To adapt and validate miRNAs for clinical use, we investigated the time-course changes in miR-122 expression levels in an acetaminophen-induced liver injury model in rats. In addition, miR-155 and miR-21 were evaluated as makers of inflammation and regeneration, respectively, to characterize liver status. Our results revealed that miR-122 is an early and sensitive biomarker of hepatocellular injury at a stage when alanine transaminase, aspartate transaminase, and total bilirubin were not detectable. However, no significant differences in the expression levels of other miRNAs (miR-155 and -21) were observed between treatment and vehicle groups. Collectively, these time-course changes in the expression levels of miRNAs may be useful as markers for clinical decision-making, in the diagnosis and treatment of DILI.

Metformin inhibits early stage diethylnitrosamine­induced hepatocarcinogenesis in rats.

Antitumor effects of metformin have recently emerged despite its original use for type II diabetes. In the present study, the effects of metformin on the development and recurrence of hepatocellular carcinoma (HCC) were investigated using the diethylnitrosamine (DEN)­induced rat model of HCC. Tumor foci were characterized by gross examination and by histopathological characteristics, including proliferation, hepatic progenitor cell content and the expression of hepatocarcinoma­specific molecular markers. Potential target molecules of metformin were investigated to determine the molecular mechanism underlying the inhibitory effects of metformin on chemically induced liver tumorigenesis. The antitumor effects of metformin were increased by the reduction of surface nodules and decreased the incidence of altered hepatocellular foci, hepatocellular adenoma and carcinoma. Also, decreased expression levels of glutathione S­transferase placental form, proliferating cell nuclear antigen and cytokeratin 8 described the inhibitory effects of metformin on HCC. In the present study, Wistar rats receiving treatment with DEN were administered metformin for 16 weeks. In addition, metformin suppressed liver tumorigenesis via an AMPK­dependent pathway. These results suggested that metformin has promising effects on the early stage of HCC in rats. Therefore, metformin may be used for the prevention of HCC recurrence following primary chemotherapy for HCC and/or for high­risk patients, including chronic hepatitis and cirrhosis.

Evaluation of Nonalcoholic Fatty Liver Disease in C57BL/6J Mice by Using MRI and Histopathologic Analyses.

Nonalcoholic fatty liver disease (NAFLD) can lead to cirrhosis, hepatocellular carcinoma, and ultimately death. Magnetic resonance techniques are accurate, noninvasive methods for evaluating hepatic steatosis but, in animals, have not been fully validated against histologic findings. We sought to validate the MRI fat-signal fraction (MRI-FSF) used for diagnosing NAFLD in human nonclinical trials by comparing MRI data with histopathologic findings in C57BL/6J mice (n = 24) fed normal chow (controls) or a methionine- and choline-deficient (MCD) diet to induce NAFLD. Axial T2-weighted fast spin-echo images were used to examine the entire liver. For histopathologic analyses, liver slides were evaluated for hepatic steatosis according to the NAFLD activity score. Pearson correlation coefficient and receiver operating characteristics analyses were performed. According to the fat-fraction signal, the mean percentage of liver fat in mice with induced NAFLD was 57%, which correlated with the histologically determined steatosis grade. The proton-density fat fraction effectively distinguished severe from mild hepatic steatosis, with an AUC of 0.92. Evaluation accuracy decreased when lobular inflammation and hepatocellular ballooning were considered. This study showed strong concurrence between MRI-FSF and histopathologic steatosis in a murine model of NAFLD. MRI-FSF had moderate sensitivity and specificity in this context. These results confirm that the MRI is a useful biomarker of hepatic steatosis in NAFLD in murine model.

Carcinogenicity of metamifop, a novel herbicide, in Wistar rats following oral administration for 104 weeks.

Metamifop is a novel herbicide with as yet undetermined properties. To assess its carcinogenicity, metamifop was mixed into standard rodent chow and fed to male and female Wistar rats at doses of 10, 100 and 750ppm for 104weeks. The viability/mortality of these rats was not affected by treatment with metamifop. Treatment had no significant effects on clinical parameters, and food consumption. Males and females fed 750ppm of metamifop for 104weeks showed decreases in body weight and body weight gain. Histopathological examination revealed that treatment with metamifop reduced non-neoplastic findings (chronic progressive nephropathy, tubular basophilia, tubular casts, glomerulosclerosis, basophilic and clear cell foci, senile atrophy, and mesothelial hyperplasia) and reduced neoplastic findings (thymoma, pituitary adenoma, and mammary fibroadenoma and adenocarcinoma in females, and mesenteric lymph node hemangioma in males) compared with control groups. Benign granulosa cell tumors were increased in a dose-dependent manner. As metamifop did not show any genotoxic potential, and there was no correlation between ovarian cancer and increased gonadal hormone levels in humans, the granulosa cell tumors observed in female rats fed a high dose of metamifop were considered not relevant to humans.

Standardized Salvia miltiorrhiza extract suppresses hepatic stellate cell activation and attenuates steatohepatitis induced by a methionine-choline deficient diet in mice.

The aim of this study was to examine the effect of standardized extract of Salvia miltiorrhiza (SME) on gene and protein expression of non-alcoholic steatohepatitis (NASH)-related factors in activated human hepatic stellate cells (HSC), and in mice with steatohepatitis induced by a methionine-choline deficient (MCD) diet. Male C57BL/6J mice were placed on an MCD or control diet for 8 weeks and SME (0, 0.1, 0.5 and 1 mg/kg body weight) was administered orally every other day for 4 or 6 weeks. HSCs from the LX-2 cell line were treated with transforming growth factor ß-1 (TGF-ß1) or TGF-ß1 plus SME (0.1-10 µg/mL). To investigate the effect of SME on reactive oxygen species (ROS)-induced condition, LX-2 cells were treated with hydrogen peroxide (H2O2) or H2O2 plus SME (0.1-100 µg/mL). MCD administration for 12 weeks increased mRNA expression of tumor necrosis factor (TNF-α), TGF-ß1, interleukin-1ß (IL-1ß), C-reactive protein (CRP), α-smooth muscle actin (α-SMA), type I collagen, matrix metalloproteinase-2 (MMP-2) and MMP-9. TGF-ß1-induced LX-2 cells exhibited similar gene expression patterns. SME treatment significantly reduced the mRNA and protein expression of NASH-related factors in the mouse model and HSCs. Histopathological liver analysis showed improved non-alcoholic fatty liver disease (NAFLD) activity and fibrosis score in SME-treated mice. The in vivo studies showed that SME had a significant effect at low doses. These results suggest that SME might be a potential therapeutic candidate for NAFLD treatment.