Ezh2 (Enhancer of zeste homolog 2) protein is the enzymatic component of the Polycomb repressive complex 2 (PRC2), which represses gene expression by methylating lysine 27 of histone H3 (H3K27) and regulates cell proliferation and differentiation during embryonic development. Recently, hot-spot mutations of Ezh2 were identified in diffused large B-cell lymphomas and follicular lymphomas. To investigate if tumor growth is dependent on the enzymatic activity of Ezh2, we developed a potent and selective small molecule inhibitor, EI1, which inhibits the enzymatic activity of Ezh2 through direct binding to the enzyme and competing with the methyl group donor S-Adenosyl methionine. EI1-treated cells exhibit genome-wide loss of H3K27 methylation and activation of PRC2 target genes. Furthermore, inhibition of Ezh2 by EI1 in diffused large B-cell lymphomas cells carrying the Y641 mutations results in decreased proliferation, cell cycle arrest, and apoptosis. These results provide strong validation of Ezh2 as a potential therapeutic target for the treatment of cancer.

Sirtuin 1 (Sirt1) is a NAD + -dependent deacetylase that exerts many of the pleiotropic effects of oxidative metabolism. Due to local hypoxia and hypertonicity, the renal medulla is subject to extreme oxidative stress. Here, we set out to investigate the role of Sirt1 in the kidney. Our initial analysis indicated that it was abundantly expressed in mouse renal medullary interstitial cells in vivo. Knocking down Sirt1 expression in primary mouse renal medullary interstitial cells substantially reduced cellular resistance to oxidative stress, while pharmacologic Sirt1 activation using either resveratrol or SRT2183 improved cell survival in response to oxidative stress. The unilateral ureteral obstruction (UUO) model of kidney injury induced markedly more renal apoptosis and fibrosis in Sirt1 +/-mice than in wild-type controls, while pharmacologic Sirt1 activation substantially attenuated apoptosis and fibrosis in wild-type mice. Moreover, Sirt1 deficiency attenuated oxidative stress-induced COX2 expression in cultured mouse renal medullary interstitial cells, and Sirt1 +/-mice displayed reduced UUO-induced COX2 expression in vivo. Conversely, Sirt1 activation increased renal medullary interstitial cell COX2 expression both in vitro and in vivo. Furthermore, exogenous PGE 2 markedly reduced apoptosis in Sirt1-deficient renal medullary interstitial cells following oxidative stress. Taken together, these results identify Sirt1 as an important protective factor for mouse renal medullary interstitial cells following oxidative stress and suggest that the protective function of Sirt1 is partly attributable to its regulation of COX2 induction. We therefore suggest that Sirt1 provides a potential therapeutic target to minimize renal medullary cell damage following oxidative stress.

The protein methyltransferase Set7/9 was recently shown to regulate p53 activity in cancer cells. However, the impact of Set7/9 on p53 function in vivo is unclear. To explore these issues, we created a null allele of Set7/9 in mice. Cells from Set7/9 mutant mice fail to methylate p53 K369, are unable to induce p53 downstream targets upon DNA damage, and are predisposed to oncogenic transformation. Importantly, we find that methylation of p53 by Set7/9 is required for the binding of the acetyltransferase Tip60 to p53 and for the subsequent acetylation of p53. We provide the first genetic evidence demonstrating that lysine methylation of p53 by Set7/9 is important for p53 activation in vivo and suggest a mechanistic link between methylation and acetylation of p53 through Tip60.

Acute kidney injury (AKI) is a critical condition with a mortality rate as high as 50% and significantly contributes to the burden of end-stage renal disease (ESRD) requiring renal replacement therapy. The incidence and prognosis of AKI have been shown to vary with patient age, with younger individuals being more resistant to AKI. In mice, clamping the renal artery for 45 min causes substantial kidney damage in 4-month-old animals but only mild renal injury in 2-month-old animals. Here, younger mice were found to express higher levels of the NAD(+)-dependent histone deacetylase SIRT1 in the kidney. A small molecule SIRT1 activator, SRT-1720, markedly improved renal tubular pathology and overall renal function in adult mice following ischemia/reperfusion. Genetic ablation of one allele (SIRT1(+/-)) significantly enhanced the level of kidney damage relative to that in wild-type (SIRT1(+/+)) mice. The mechanisms underlying the protective effect of SIRT1 included the suppression of cell apoptosis. Hence, our results suggest that SIRT1 might be a novel therapeutic target for ischemia/reperfusion-induced kidney damage.

Our study found a strong association between periodontitis and COPD, and PI seemed to be a major periodontal factor for predicting COPD among Chinese adults.

MicroRNAs (miRNAs) are a class of small noncoding RNA molecules that play important roles in carcinogenesis and tumor progression. In this study, we investigated the roles and mechanisms of miR-140 in human non-small cell lung cancer (NSCLC). We found that miR-140 is significantly downregulated in NSCLC tissues and cell lines. Both gain-of-function and loss-of-function studies demonstrated that miR-140 suppresses NSCLC cell proliferation, migration, and invasion in vitro. Importantly, overexpression of miR-140 effectively repressed tumor growth and metastasis in nude mouse models. Integrated analysis identified IGF1R as a direct and functional target of miR-140. Knockdown of IGF1R inhibited cell proliferation and invasion resembling that of miR-140 overexpression, while overexpression of IGF1R attenuated the function of miR-140 in NSCLC cells. Together, our results highlight the significance of miR-140 and IGF1R in the development and progression of NSCLC.

No prediction rule is currently available for advanced colorectal neoplasms, defined as invasive cancer, an adenoma of 10 mm or more, a villous adenoma, or an adenoma with high-grade dysplasia, in average-risk Chinese. In this study between 2006 and 2008, a total of 7,541 average-risk Chinese persons aged 40 years or older who had complete colonoscopy were included. The derivation and validation cohorts consisted of 5,229 and 2,312 persons, respectively. A prediction rule was developed from a logistic regression model and then internally and externally validated. The prediction rule comprised 8 variables (age, sex, smoking, diabetes mellitus, green vegetables, pickled food, fried food, and white meat), with scores ranging from 0 to 14. Among the participants with low-risk (≤3) or high-risk (>3) scores in the validation cohort, the risks of advanced neoplasms were 2.6% and 10.0% (P < 0.001), respectively. If colonoscopy was used only for persons with high risk, 80.3% of persons with advanced neoplasms would be detected while the number of colonoscopies would be reduced by 49.2%. The prediction rule had good discrimination (area under the receiver operating characteristic curve = 0.74, 95% confidence interval: 0.70, 0.78) and calibration (P = 0.77) and, thus, provides accurate risk stratification for advanced neoplasms in average-risk Chinese.

BackgroundUrinary excretion of bisphenol A (BPA) and alkylphenols (APs) was used as a biomarker in most previous studies, but no study has investigated whether urinary excretion of these environmental phenols differed by renal function.ObjectiveWe estimated the association between renal function and urinary excretion of BPA and APs.MethodsAnalyses were conducted using data from the National Health and Nutrition Examination Survey (NHANES) 2003–2006. Renal function was measured as estimated glomerular filtration rate (eGFR) calculated by the Modification of Diet in Renal Disease (MDRD) Study equation and by the newly developed Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Regression models were used to calculate geometric means of urinary BPA and APs excretion by eGFR category (≥ 90, 60–90, < 60 mL/min/m2) after adjusting for potential confounding factors.ResultsWhen we used the MDRD Study equation, participants without known renal disease (n = 2,573), 58.2% (n = 1,499) had mildly decreased renal function or undiagnosed chronic kidney disease. The adjusted geometric means for urinary BPA excretion decreased with decreasing levels of eGFR (p for trend = 0.04). The associations appeared primarily in females (p for trend = 0.03). Urinary triclosan excretion decreased with decreasing levels of eGFR (p for trend < 0.01) for both males and females, and the association primarily appeared in participants < 65 years of age. The association between BPA and eGFR was nonsignificant when we used the CKD-EPI equation.ConclusionsUrinary excretion of triclosan, and possibly BPA, decreased with decreasing renal function. The associations might differ by age or sex. Further studies are necessary to replicate our results and understand the mechanism.