Obesity promotes aerobic glycolysis in prostate cancer cells

Effects of Dietary Yeast β-Glucan Supplementation on Meat Quality, Antioxidant Capacity and Gut Microbiota of Finishing Pigs

Yeast β-glucan is a natural antioxidant and has been reported to improve growth performance of piglets, but its application in improving pork quality is limited. This study investigated the effects of dietary yeast β-glucan supplementation on meat quality, antioxidant capacity and gut microbiota of finishing pigs. In a 40-day experiment, ninety finishing pigs (Duroc × Landrace × Yorkshire, 70.47 ± 0.04 kg) were randomly allocated into five treatments including a basal diet supplemented with 0, 50, 100, 200 and 400 mg/kg yeast β-glucan. Results showed that yeast β-glucan significantly increased pH45 min (linear and quadratic, p < 0.01) and a*45 min (linear, p < 0.05), and reduced cooking loss (linear, p < 0.05) and drip loss (quadratic, p < 0.05) of meat in finishing pigs. Importantly, the 200 mg/kg group exhibited the highest values of pH45 min (p < 0.01) and the lowest values of drip loss (p < 0.05), accompanied by a decreased lactate content (p < 0.05) and glycolytic potential (p < 0.05). Dietary supplementation of 200 mg/kg yeast β-glucan markedly increased catalase (CAT) (p < 0.05), superoxide dismutase (SOD) (p < 0.05) and total antioxidant capacity (T-AOC) (p < 0.01) activities in skeletal muscle. Moreover, WPS-2 abundance was decreased significantly in colonic digesta by 200 mg/kg yeast β-glucan and exhibited a positive association with muscle lactate content and drip loss. Together, dietary 200 mg/kg yeast β-glucan supplementation effectively improved pH value and the water-holding capacity of fresh meat through reducing muscle postmortem glycolysis, increasing antioxidant capacity and altering the gut microbiota composition of finishing pigs.

Obesity: The Fat Tissue Disease Version of Cancer

Obesity is a disease with high potential for fatality. It perfectly fits the disease definition, as cancer does. This is because it damages body structure and functions, both mechanically and biologically, and alters physical, mental, and social health. In addition, it shares many common morbid characteristics with the most feared disease, cancer. For example, it is influenced by a sophisticated interaction between a person’s genetics, the environment, and an increasing number of other backgrounds. Furthermore, it displays abnormal cell growth and proliferation events, only limited to white fat, resulting in adipose tissue taking up an increasing amount of space within the body. This occurs through fat “metastases” and via altered signaling that further aggravates the pathology of obesity by inducing ubiquitous dishomeostasis. These metastases can be made graver by angiogenesis, which might boost diseased tissue growth. More common features with cancer include its progressive escalation through different levels of severity and its possibility of re-onset after recovery. Despite all these similarities with cancer, obesity is substantially less agitating for most people. Thus, the ideas proposed herein could have utility to sensitize the public opinion about the hard reality of obesity. This is increasingly needed, as the obesity pandemic has waged a fierce war against our bodies and society in general, while there is still doubt about whether it is a real disease or not. Hence, raising public consciousness to properly face health issues is crucial to improving our health instead of gaining weight unhealthily. It is obviously illogical to fight cancer extremely seriously on the one hand and to consider dying with obesity as self-inflicted on the other. In fact, obesity merits a top position among the most lethal diseases besides cancer.

Silibinin Differentially Decreases the Aggressive Cancer Phenotype in an In Vitro Model of Obesity and Prostate Cancer

Aim: Obesity increases the risk for aggressive and fatal prostate cancer (PCa). The bioactive compound silibinin has been researched for its chemopreventative properties and may benefit obese or overweight individuals with PCa.Methods: This study used an in vitro model of obesity exposing prostate cancer cells to sera from obese, overweight, or normal weight males with or without the addition of silibinin. Molecular activity was assayed as well as the phenotype of PCa cells with various treatments.Results: Obesity increased the expression of proliferative signaling including COX-2, IL-6, AKT, ERK, and AR, which was attenuated with silibinin. Cell growth, and invasive capacity of prostate cancer cells was increased with obese and overweight sera, and silibinin was able to mitigate this affect. However, there are limitations to this study in that an in vivo model was not used to validate these in vitro results nor a co-culture model, which may better recapitulate the tumor microenvironment.Conclusions: Silibinin may be a safe intervention for those with or at risk for prostate cancer, and it may be the most beneficial for obese or overweight males.

Impact of obesity and overweight on DNA stability: Few facts and many hypotheses

Health authorities are alarmed worldwide about the increase of obesity and overweight in the last decades which lead to adverse health effects including inflammation, cancer, accelerated aging and infertility. We evaluated the state of knowledge concerning the impact of elevated body mass on genomic instability. Results of investigations with humans (39 studies) in which DNA damage was monitored in lymphocytes and sperm cells, are conflicting and probably as a consequence of heterogeneous study designs and confounding factors (e.g. uncontrolled intake of vitamins and minerals and consumption of different food types). Results of animal studies with defined diets (23 studies) are more consistent and show that excess body fat causes DNA damage in multiple organs including brain, liver, colon and testes. Different molecular mechanisms may cause genetic instability in overweight/obese individuals. ROS formation and lipid peroxidation were found in several investigations and may be caused by increased insulin, fatty acid and glucose levels or indirectly via inflammation. Also reduced DNA repair and formation of advanced glycation end products may play a role but more data are required to draw firm conclusions. Reduction of telomere lengths and hormonal imbalances are characteristic for overweight/obesity but the former effects are delayed and moderate and hormonal effects were not investigated in regard to genomic instability in obese individuals. Increased BMI values affect also the activities of drug metabolizing enzymes which activate/detoxify genotoxic carcinogens, but no studies concerning the impact of these alterations of DNA damage in obese individuals are available. Overall, the knowledge concerning the impact of increased body weight and DNA damage is poor and further research is warranted to shed light on this important issue.

Translating Mechanism-Based Strategies to Break the Obesity-Cancer Link: A Narrative Review

Prevalence of obesity, an established risk factor for many cancers, has increased dramatically over the past 50 years in the United States and across the globe. Relative to normoweight cancer patients, obese cancer patients often have poorer prognoses, resistance to chemotherapies, and are more likely to develop distant metastases. Recent progress on elucidating the mechanisms underlying the obesity-cancer connection suggests that obesity exerts pleomorphic effects on pathways related to tumor development and progression and, thus, there are multiple opportunities for primary prevention and treatment of obesity-related cancers. Obesity-associated alterations, including systemic metabolism, adipose inflammation, growth factor signaling, and angiogenesis, are emerging as primary drivers of obesity-associated cancer development and progression. These obesity-associated host factors interact with the intrinsic molecular characteristics of cancer cells, facilitating several of the hallmarks of cancer. Each is considered in the context of potential preventive and therapeutic strategies to reduce the burden of obesity-related cancers. In addition, this review focuses on emerging mechanisms behind the obesity-cancer link, as well as relevant dietary interventions, including calorie restriction, intermittent fasting, low-fat diet, and ketogenic diet, that are being implemented in preclinical and clinical trials, with the ultimate goal of reducing incidence and progression of obesity-related cancers.

Transcriptome evaluation of the relation between body mass index and prostate cancer outcomes

BACKGROUND

Large epidemiological studies indicate that an increased body mass index (BMI) is associated with increased prostate cancer (PCa) mortality. Data indicate that there is no association between elevated metabolic pathway proteins and PCa mortality. There are no published studies evaluating the relation between BMI and metabolic pathways with respect to PCa outcomes with a genomics approach.

METHODS

The Decipher Genomic Resource Information Database was queried for patients who had undergone prostatectomy and had BMI information available. These patients came from Thomas Jefferson University (TJU) and Johns Hopkins Medical Institution (JHMI); the latter provided 2 cohorts (I and II). A high-BMI group (≥30 kg/m² ) and a low-BMI group (<25 kg/m² ) were identified, and genomic data were interrogated for differentially expressed genes with an interquartile range filter and a Wilcoxon test. P values were adjusted for multiple testing with the Benjamini-Hochberg false-discovery rate method.

RESULTS

A total of 477 patients with a median follow-up of 108 months had BMI information available. Two genes were found to interact with BMI in both the JHMI I cohort and the TJU cohort, but there was no statistical significance after adjustments for multiple comparisons. Aberrant metabolic gene expression was significantly correlated with distant metastases (P < .05). No relation was found between BMI and metastases or overall survival (both P values > .05).

CONCLUSIONS

In a genomic analysis of prostatectomy specimens, metabolic gene expression, but not BMI, was associated with PCa metastases. Cancer 2017;123:2240-2247. © 2017 American Cancer Society.

Influence of Body Mass Index on the Prognostic Value of Tumor ¹⁸F-FDG Uptake in Stage I Non-Small Cell Lung Cancer

Background

The impact of host energy balance status on outcome of lung cancer has not been fully explored. It is also unknown if there is a potential modifying effect of body mass index (BMI) on tumor cell behavior in patients with early-stage non-small cell lung cancer (NSCLC). We therefore investigated the interactive effects of tumor [¹⁸F]-fluorodeoxyglucose (FDG) avidity and BMI.

Methods

We investigated 1,197 patients with stage I NSCLC who underwent preoperative FDG positron emission tomography followed by curative resection. The primary outcome measure was disease-free survival (DFS). A multivariable Cox proportional hazards model was used to assess the potential independent effects of the prognostic variables. A stratified Cox regression analysis was also performed to assess the potential modifying effects of BMI on the relationship between tumor FDG uptake and patient survival.

Results

There were 145 tumor recurrences and 19 deaths during a median follow-up of 30 months. Tumor-related variables, including tumor size, maximum standardized uptake value (SUVmax), histologic cell type, differentiation, lymphovascular invasion, and visceral pleural invasion, did not differ significantly according to BMI status. In multivariable Cox regression analysis, overweight or obesity [hazard ratio (HR), 0.59; 95% CI, 0.43–0.81; P = 0.001] and tumor SUVmax (HR, 1.72; 95% CI, 1.43–2.07; P < 0.001) were significantly associated with DFS. There was a significant modifying effect of BMI (P for interaction < 0.001 in multivariable analysis). High tumor SUVmax was more strongly associated with worse DFS in normal weight patients (HR, 4.72; 95% CI, 2.77–8.06; P < 0.001) than in overweight or obese patients (HR, 2.61; 95% CI, 1.58–4.31; P < 0.001).

Conclusions

Tumor FDG avidity is an independent predictor of DFS in patients with early-stage NSCLC and this prognostic value was strengthened in normal weight patients than in overweight or obese patients. These results suggest that the host-tumor interaction between host energy balance status and tumor glucose metabolism plays an important role in the outcome of early-stage NSCLC.

Examining the connectivity between different cellular processes in the Barrett tissue microenvironment

In Barrett associated tumorigenesis, oxidative phosphorylation and glycolysis are reprogrammed early in the disease sequence and act mutually to promote disease progression. However, the link between energy metabolism and its connection with other central cellular processes within the Barrett microenvironment is unknown. The aim of this study was to examine the relationship between metabolism (ATP5B/GAPDH), hypoxia (HIF1α), inflammation (IL1β/SERPINA3), p53 and obesity status using in-vivo and ex-vivo models of Barrett oesophagus. At the protein level, ATP5B (r = 0.71, P < 0.0001) and p53 (r = 0.455, P = 0.015) were found to be strongly associated with hypoxia. In addition, levels of ATP5B (r = 0.53, P = 0.0031) and GAPDH (r = -0.39, P = 0.0357) were positively associated with p53 expression. Moreover, we demonstrate that ATP5B (r = 0.8, P < 0.0001) and GAPDH (r = 0.43, P = 0.022) were positively associated with IL1β expression. Interestingly, obesity was negatively associated with oxidative phosphorylation (r = -0.6016, P = 0.0177) but positively associated with glycolysis (r = 0.743, P = 0.0015). Comparable correlations were exhibited in the ex-vivo explant tissue between metabolism, p53, hypoxia, inflammation and angiogenesis (P < 0.05). We have shown that metabolism is closely linked with many cellular processes in the Barrett tissue microenvironment.