SummaryObesity is a major driver of cancer, especially hepatocellular carcinoma (HCC). The prevailing view is that non-alcoholic steatohepatitis (NASH) and fibrosis or cirrhosis are required for HCC in obesity. Here, we report that NASH and fibrosis and HCC in obesity can be dissociated. We show that the oxidative hepatic environment in obesity inactivates the STAT-1 and STAT-3 phosphatase T cell protein tyrosine phosphatase (TCPTP) and increases STAT-1 and STAT-3 signaling. TCPTP deletion in hepatocytes promoted T cell recruitment and ensuing NASH and fibrosis as well as HCC in obese C57BL/6 mice that normally do not develop NASH and fibrosis or HCC. Attenuating the enhanced STAT-1 signaling prevented T cell recruitment and NASH and fibrosis but did not prevent HCC. By contrast, correcting STAT-3 signaling prevented HCC without affecting NASH and fibrosis. TCPTP-deletion in hepatocytes also markedly accelerated HCC in mice treated with a chemical carcinogen that promotes HCC without NASH and fibrosis. Our studies reveal how obesity-associated hepatic oxidative stress can independently contribute to the pathogenesis of NASH, fibrosis, and HCC.
Apoptotic cell death is a hallmark of the loss of insulin producing beta-cells in all forms of diabetes mellitus. Current treatment fails to halt the decline in functional beta-cell mass. Strategies to prevent beta-cell apoptosis and dysfunction are urgently needed. Here, we identified Mammalian Sterile 20-like kinase 1 (MST1) as a critical regulator of apoptotic beta-cell death and function. MST1 was strongly activated in beta-cells under diabetogenic conditions and correlated with beta-cell apoptosis. MST1 specifically induced the mitochondrial-dependent pathway of apoptosis in beta-cells through up-regulation of the BH3-only protein Bim. MST1 directly phosphorylated PDX1 at Thr11, resulting in its ubiquitination, degradation and impaired insulin secretion. Mst1 deficiency completely restored normoglycemia, beta-cell function and survival in vitro and in vivo. We show MST1 as novel pro-apoptotic kinase and key mediator of apoptotic signaling and beta-cell dysfunction, which may serve as target for the development of novel therapies for diabetes.
Background Oesophageal cancer is a common and often fatal cancer that has two main histological subtypes: oesophageal squamous cell carcinoma and oesophageal adenocarcinoma. Updated statistics on the incidence and mortality of oesophageal cancer, and on the disability-adjusted life-years (DALYs) caused by the disease, can assist policy makers in allocating resources for prevention, treatment, and care of oesophageal cancer. We report the latest estimates of these statistics for 195 countries and territories between 1990 and 2017, by age, sex, and Socio-demographic Index (SDI), using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD). MethodsWe used data from vital registration systems, vital registration-samples, verbal autopsy records, and cancer registries, combined with relevant modelling, to estimate the mortality, incidence, and burden of oesophageal cancer from 1990 to 2017. Mortality-to-incidence ratios (MIRs) were estimated and fed into a Cause of Death Ensemble model (CODEm) including risk factors. MIRs were used for mortality and non-fatal modelling. Estimates of DALYs attributable to the main risk factors of oesophageal cancer available in GBD were also calculated. The proportion of oesophageal squamous cell carcinoma to all oesophageal cancers was extracted by use of publicly available data, and its variation was examined against SDI, the Healthcare Access and Quality (HAQ) Index, and available risk factors in GBD that are specific for oesophageal squamous cell carcinoma (eg, unimproved water source and indoor air pollution) and for oesophageal adenocarcinoma (gastro-oesophageal reflux disease).Findings There were 473 000 (95% uncertainty interval [95% UI] 459 000-485 000) new cases of oesophageal cancer and 436 000 (425 000-448 000) deaths due to oesophageal cancer in 2017. Age-standardised incidence was 5•9 (5•7-6•1) per 100 000 population and age-standardised mortality was 5•5 (5•3-5•6) per 100 000. Oesophageal cancer caused 9•78 million (9•53-10•03) DALYs, with an age-standardised rate of 120 (117-123) per 100 000 population. Between 1990 and 2017, age-standardised incidence decreased by 22•0% (18•6-25•2), mortality decreased by 29•0% (25•8-32•0), and DALYs decreased by 33•4% (30•4-36•1) globally. However, as a result of population growth and ageing, the total number of new cases increased by 52•3% (45•9-58•9), from 310 000 (300 000-322 000) to 473 000 (459 000-485 000); the number of deaths increased by 40•0% (34•1-46•3), from 311 000 (301 000-323 000) to 436 000 (425 000-448 000); and total DALYs increased by 27•4% (22•1-33•1), from 7•68 million (7•42-7•97) to 9•78 million (9•53-10•03). At the national level, China had the highest number of incident cases (235 000 [223 000-246 000]), deaths (213 000 [203 000-223 000]), and DALYs (4•46 million [4•25-4•69]) in 2017. The highest national-level agestandardised incidence rates in 2017 were observed in Malawi (23•0 [19•4-26•5] per 100 000 population) and Mongolia (18•5 [16•4-20•8] per 100 000). In 2017, age-standardis...
Workers with self-control problems do not work as hard as they would like. This changes the logic of agency theory by partly aligning the interests of the firm and worker: both now value contracts that elicit more effort in the future. Three findings from a year-long field experiment with data entry workers suggest the quantitative importance of self control at work. First, workers choose dominated contracts-which penalize low output but provide no greater reward for high output-36% of the time to motivate their future selves; use of these contracts increases output by the same amount as an 18% increase in the piece-rate. Second, effort increases as the (randomly assigned) payday gets closer: output rises 8% over the pay week; calibrations show that justifying this would require a 4% daily exponential discount rate. Third, for both findings there is significant and correlated heterogeneity: workers with larger payday effects are both more likely to choose dominated contracts and show greater output increases under them. This correlation grows with experience, consistent with the hypothesis that workers learn about their self-control problems over time. Self-control problems among workers could potentially lead firms to either adopt high-powered incentives or impose work rules to allow monitoring of worker effort.
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