Digital Quantification of Tumor Cellularity as a Novel Prognostic Feature of Non-Small Cell Lung Carcinoma

Non-small cell lung carcinoma is currently staged based on the size and involvement of other structures. Tumor size may be a surrogate measure of the total number of tumor cells. A recently revised reporting system for adenocarcinoma incorporates high-risk histologic patterns, which may have increased cellular density. Modern digital image analysis tools can be utilized to automate the quantification of cells. In this study, we tested the hypothesis that tumor cellularity can be used as a novel prognostic tool for lung cancer. Digital slides from The Cancer Genome Atlas lung adenocarcinoma (ADC) data set (n = 213) and lung squamous cell carcinoma (SCC) data set (n = 90) were obtained and analyzed using QuPath. The number of tumor cells was normalized with the surface area of the tumor to provide a measure of tumor cell density. Tumor cellularity was calculated by multiplying the size of the tumor with the cell density. Major histologic patterns and grade were compared with the tumor density of the lung ADC and lung SCC cases. The overall and progression-free survival were compared between groups of high and low tumor cellularity. High-grade histologic patterns in the ADC and SCC cases were associated with greater tumor densities compared with low-grade patterns. Cases with lower tumor cellularity had improved overall and progression-free survival compared with cases with higher cellularity. These results support tumor cellularity as a novel prognostic tool for non-small cell lung carcinoma that considers tumor stage and grade elements.

Cyclin-like proteins tip regenerative balance in the liver to favour cancer formation

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide. A variety of factors can contribute to the onset of this disease, including viral infection, obesity, alcohol abuse and non-alcoholic fatty liver disease (NAFLD). These stressors predominantly introduce chronic inflammation leading to liver cirrhosis and finally the onset of HCC; however, approximately 20% of HCC cases arise in the absence of cirrhosis via a poorly defined mechanism. The atypical cyclin-like protein Spy1 is capable of overriding cell cycle checkpoints, promoting proliferation and has been implicated in HCC. We hypothesize that Spy1 promotes sustained proliferation making the liver more susceptible to accumulation of deleterious mutations, leading to the development of non-cirrhotic HCC. We report for the first time that elevation of Spy1 within the liver of a transgenic mouse model leads to enhanced spontaneous liver tumourigenesis. We show that the abundance of Spy1 enhanced fat deposition within the liver and decreased the inflammatory response. Interestingly, Spy1 transgenic mice have a significant reduction in fibrosis and sustained rates of hepatocyte proliferation, and endogenous levels of Spy1 are downregulated during the normal fibrotic response. Our results provide support that abnormal regulation of Spy1 protein drives liver tumorigenesis in the absence of elevated fibrosis and, hence, may represent a potential mechanism behind non-cirrhotic HCC. This work may implicate Spy1 as a prognostic indicator and/or potential target in the treatment of diseases of the liver, such as HCC. The cyclin-like protein Spy1 enhances lipid deposition and reduces fibrosis in the liver. Spy1 also promotes increased hepatocyte proliferation and onset of non-cirrhotic hepatocellular carcinoma (HCC). Thus, Spy1 may be used as a potential target in the treatment of HCC.

The citrus flavonoid nobiletin confers protection from metabolic dysregulation in high-fat-fed mice independent of AMPK

Obesity, dyslipidemia, and insulin resistance, the increasingly common metabolic syndrome, are risk factors for CVD and type 2 diabetes that warrant novel therapeutic interventions. The flavonoid nobiletin displays potent lipid-lowering and insulin-sensitizing properties in mice with metabolic dysfunction. However, the mechanisms by which nobiletin mediates metabolic protection are not clearly established. The central role of AMP-activated protein kinase (AMPK) as an energy sensor suggests that AMPK is a target of nobiletin. We tested the hypothesis that metabolic protection by nobiletin required phosphorylation of AMPK and acetyl-CoA carboxylase (ACC) in mouse hepatocytes, in mice deficient in hepatic AMPK (Ampkβ1 ^-/-), in mice incapable of inhibitory phosphorylation of ACC (AccDKI), and in mice with adipocyte-specific AMPK deficiency (iβ1β2AKO). We fed mice a high-fat/high-cholesterol diet with or without nobiletin. Nobiletin increased phosphorylation of AMPK and ACC in primary mouse hepatocytes, which was associated with increased FA oxidation and attenuated FA synthesis. Despite loss of ACC phosphorylation in Ampkβ1 ^-/- hepatocytes, nobiletin suppressed FA synthesis and enhanced FA oxidation. Acute injection of nobiletin into mice did not increase phosphorylation of either AMPK or ACC in liver. In mice fed a high-fat diet, nobiletin robustly prevented obesity, hepatic steatosis, dyslipidemia, and insulin resistance, and it improved energy expenditure in Ampkβ1 ^-/-, AccDKI, and iβ1β2AKO mice to the same extent as in WT controls. Thus, the beneficial metabolic effects of nobiletin in vivo are conferred independently of hepatic or adipocyte AMPK activation. These studies further underscore the therapeutic potential of nobiletin and begin to clarify possible mechanisms.

Prevention of Diet-Induced Metabolic Dysregulation, Inflammation, and Atherosclerosis in Ldlr −/− Mice by Treatment With the ATP-Citrate Lyase Inhibitor Bempedoic Acid

Objective—

Bempedoic acid (ETC-1002, 8-hydroxy-2,2,14,14-tetramethylpentadecanedioic acid) is a novel low-density lipoprotein cholesterol–lowering compound. In animals, bempedoic acid targets the liver where it inhibits cholesterol and fatty acid synthesis through inhibition of ATP-citrate lyase and through activation of AMP-activated protein kinase. In this study, we tested the hypothesis that bempedoic acid would prevent diet-induced metabolic dysregulation, inflammation, and atherosclerosis.

Approach and Results—

Ldlr −/− mice were fed a high-fat, high-cholesterol diet (42% kcal fat, 0.2% cholesterol) supplemented with bempedoic acid at 0, 3, 10 and 30 mg/kg body weight/day. Treatment for 12 weeks dose-dependently attenuated diet-induced hypercholesterolemia, hypertriglyceridemia, hyperglycemia, hyperinsulinemia, fatty liver and obesity. Compared to high-fat, high-cholesterol alone, the addition of bempedoic acid decreased plasma triglyceride (up to 64%) and cholesterol (up to 50%) concentrations, and improved glucose tolerance. Adiposity was significantly reduced with treatment. In liver, bempedoic acid prevented cholesterol and triglyceride accumulation, which was associated with increased fatty acid oxidation and reduced fatty acid synthesis. Hepatic gene expression analysis revealed that treatment significantly increased expression of genes involved in fatty acid oxidation while suppressing inflammatory gene expression. In full-length aorta, bempedoic acid markedly suppressed cholesteryl ester accumulation, attenuated the expression of proinflammatory M1 genes and attenuated the iNos / Arg1 ratio. Treatment robustly attenuated atherosclerotic lesion development in the aortic sinus by 44%, with beneficial changes in morphology, characteristic of earlier-stage lesions.

Conclusions—

Bempedoic acid effectively prevents plasma and tissue lipid elevations and attenuates the onset of inflammation, leading to the prevention of atherosclerotic lesion development in a mouse model of metabolic dysregulation.

Abstract 244: The Flavonoids Naringenin and Nobiletin Stimulate the AMPKinase Pathway in Primary Mouse Hepatocytes

Dyslipidemia associated with insulin resistance and obesity are core features of the metabolic syndrome and type 2 diabetes, which contribute significantly to atherosclerosis. In mouse models of diet-induced metabolic dysregulation, the citrus flavonoids naringenin and nobiletin prevent obesity, hepatic steatosis, apoB100 overproduction, dyslipidemia, insulin resistance and atherosclerosis. To elucidate the mechanism of action in liver we assessed flavonoid-induced activation of AMP-activated protein kinase (AMPK), the major regulator of cellular energy homeostasis, in primary mouse hepatocytes. Stimulated AMPK activity promotes catabolic, ATP-generating processes such as fatty acid (FA) oxidation while inhibiting anabolic processes such as FA synthesis. In primary C57BL/6 (WT) hepatocytes, naringenin and nobiletin increased phosphorylation (P) of AMPK and its downstream target acetyl-CoA carboxylase (ACC) in a time- and dose-dependent manner. This was associated with decreased apoB100 secretion. Phosphorylation of ACC by AMPK inhibits the formation of malonyl-CoA reducing substrate for FA synthesis in the cytosol while relieving inhibition of mitochondrial FA oxidation by malonyl-CoA. Under insulin resistant conditions stimulated by high glucose media, reduced pAMPK and pACC were reversed by flavonoid treatment in WT hepatocytes, whereas these effects were lost in Ampkβ1-/- hepatocytes. Sterol receptor element binding protein-1c, which stimulates lipogenesis, was also phosphorylated (inhibited) by flavonoid-induced AMPK activation. BAPTA, a calcium chelator or STO609, an inhibitor of Ca2+/calmodulin-dependent protein kinase kinase-beta (CaMKKβ), did not block flavonoid-induced pACC, suggesting that CaMKKβ is not required for AMPK activation by flavonoids. In chow-fed Ldlr-/- mice, acute i.p. injection of nobiletin following a fasting-refeeding protocol, depressed the respiratory exchange ratio indicative of a switch to FA oxidation. Freeze-clamped liver samples from these mice sacrificed 90 min. post injection showed marked induction of pAMPK and pACC. These results suggest that naringenin and nobiletin attenuate hepatic steatosis and metabolic dysregulation, in part, through activation of hepatic AMPK.