Statin Use is Protective Against Hepatocellular Carcinoma in Patients With Nonalcoholic Fatty Liver Disease: A Case-control Study.

BACKGROUND AND GOAL: The incidence of nonalcoholic fatty liver disease (NAFLD)-associated hepatocellular carcinoma (HCC) is rising. We aimed to characterize risk factors for NAFLD-HCC development. METHODS: We performed a retrospective case-control study of HCC cases from a cohort of NAFLD patients who underwent at least 2 computed tomography scans. NAFLD-HCC cases confirmed on contrast imaging and/or biopsy were included. Controls were NAFLD patients without HCC matched by sex and age. Clinical variables were assessed. Visceral adipose tissue and subcutaneous adipose tissue were measured by computed tomography at 2 timepoints: before HCC diagnosis and at diagnosis. RESULTS: We identified 102 subjects [34 HCC cases, 68 controls, 65% (n=66) males, mean age: 69 y] from 2002 to 2016. Cirrhosis was present in 91%. In multivariate analysis, statin use was protective against HCC [odds ratio (OR)=0.20, 95% confidence interval (CI): 0.07-0.60, P=0.004], while hypertension was a risk factor for HCC (OR=5.80, 95% CI: 2.01-16.75, P=0.001). In multivariate analysis, visceral adipose tissue in males was higher before HCC diagnosis and declined by HCC diagnosis in 86%, which was a significant difference compared with controls (OR=2.78, 95% CI: 1.10-7.44, P=0.04). CONCLUSIONS: In a cohort of NAFLD-HCC patients, statin use was protective against HCC, while hypertension conferred an increased risk. Visceral adiposity at baseline was not a risk factor, but was higher in male patients before HCC development, declining in the majority by HCC diagnosis.

The progressive ankylosis gene product ANK regulates extracellular ATP levels in primary articular chondrocytes.

INTRODUCTION: Extracellular ATP (eATP) is released by articular chondrocytes under physiological and pathological conditions. High eATP levels cause pathologic calcification, damage cartilage, and mediate pain. We recently showed that stable over-expression of the progressive ankylosis gene product, ANK, increased chondrocyte eATP levels, but the mechanisms of this effect remained unexplored. The purpose of this work was to further investigate mechanisms of eATP efflux in primary articular chondrocytes and to better define the role of ANK in this process. METHODS: We measured eATP levels using a bioluminescence-based assay in adult porcine articular chondrocyte media with or without a 10 minute exposure to hypotonic stress. siRNAs for known ATP membrane transporters and pharmacologic inhibitors of ATP egress pathways were used to identify participants involved in chondrocyte eATP release. RESULTS: eATP levels increased after exposure to hypotonic media in a calcium-dependent manner in monolayer and 3-dimensional agarose gel cultures (p < 0.001). A potent transient receptor potential vanilloid 4 (TRPV4) agonist mimicked the effects of hypotonic media. ANK siRNA suppressed basal (p < 0.01) and hypotonically-stressed (p < 0.001) ATP levels. This effect was not mediated by altered extracellular pyrophosphate (ePPi) levels, and was mimicked by the ANK inhibitor, probenecid (p < 0.001). The P2X7/4 receptor inhibitor Brilliant Blue G also suppressed eATP efflux induced by hypotonic media (p < 0.001), while ivermectin, a P2X4 receptor stimulant, increased eATP levels (p < 0.001). Pharmacologic inhibitors of hemichannels, maxianion channels and other volume-sensitive eATP efflux pathways did not suppress eATP levels. CONCLUSIONS: These findings implicate ANK and P2X7/4 receptors in chondrocyte eATP efflux. Understanding the mechanisms of eATP efflux may result in novel therapies for calcium crystal arthritis and osteoarthritis.