Obesity and Cancer: Concepts and Challenges

Metallothionein 3 Inhibits 3T3-L1 Adipocyte Differentiation via Reduction of Reactive Oxygen Species

Metallothionein 3 (MT3), also known as a neuronal growth-inhibitory factor, is a member of the metallothionein family and is involved in a variety of biological functions, including protection against metal toxicity and reactive oxygen species (ROS). However, less is known about the role of MT3 in the differentiation of 3T3-L1 cells into adipocytes. In this study, we observed that MT3 levels were downregulated during 3T3-L1 adipocyte differentiation. Mt3 overexpression inhibited adipocyte differentiation and reduced the levels of the adipogenic transcription factors C/EBPα and PPARγ. Further analyses showed that MT3 also suppressed the transcriptional activity of PPARγ, and this effect was not mediated by a direct interaction between MT3 with PPARγ. In addition, Mt3 overexpression resulted in a decrease in ROS levels during early adipocyte differentiation, while treatment with antimycin A, which induces ROS generation, restored the ROS levels. Mt3 knockdown, on the other hand, elevated ROS levels, which were suppressed upon treatment with the antioxidant N-acetylcysteine. Our findings indicate a previously unknown role of MT3 in the differentiation of 3T3-L1 cells into adipocytes and provide a potential novel target that might facilitate obesity treatment.

Sera from women with different metabolic and menopause states differentially regulate cell viability and Akt activation in a breast cancer in-vitro model

Obesity is associated with an increased incidence and aggressiveness of breast cancer and is estimated to increment the development of this tumor by 50 to 86%. These associations are driven, in part, by changes in the serum molecules. Epidemiological studies have reported that Metformin reduces the incidence of obesity-associated cancer, probably by regulating the metabolic state. In this study, we evaluated in a breast cancer in-vitro model the activation of the IR-β/Akt/p70S6K pathway by exposure to human sera with different metabolic and hormonal characteristics. Furthermore, we evaluated the effect of brief Metformin treatment on sera of obese postmenopausal women and its impact on Akt and NF-κB activation. We demonstrated that MCF-7 cells represent a robust cellular model to differentiate Akt pathway activation influenced by the stimulation with sera from obese women, resulting in increased cell viability rates compared to cells stimulated with sera from normal-weight women. In particular, stimulation with sera from postmenopausal obese women showed an increase in the phosphorylation of IR-β and Akt proteins. These effects were reversed after exposure of MCF-7 cells to sera from postmenopausal obese women with insulin resistance with Metformin treatment. Whereas sera from women without insulin resistance affected NF-κB regulation. We further demonstrated that sera from post-Metformin obese women induced an increase in p38 phosphorylation, independent of insulin resistance. Our results suggest a possible mechanism in which obesity-mediated serum molecules could enhance the development of luminal A-breast cancer by increasing Akt activation. Further, we provided evidence that the phenomenon was reversed by Metformin treatment in a subgroup of women.

Redox Imbalances in Ageing and Metabolic Alterations: Implications in Cancer and Cardiac Diseases. An Overview from the Working Group of Cardiotoxicity and Cardioprotection of the Italian Society of Cardiology (SIC)

Metabolic syndrome (MetS) is a well established risk factor for cardiovascular (CV) diseases. In addition, several studies indicate that MetS correlates with the increased risk of cancer in adults. The mechanisms linking MetS and cancer are not fully understood. Several risk factors involved in MetS are also cancer risk factors, such as the consumption of high calorie-food or high fat intake, low fibre intake, and sedentary lifestyle. Other common aspects of both cancer and MetS are oxidative stress and inflammation. In addition, some anticancer treatments can induce cardiotoxicity, including, for instance, left ventricular (LV) dysfunction and heart failure (HF), endothelial dysfunction and hypertension. In this review, we analyse several aspects of MetS, cancer and cardiotoxicity from anticancer drugs. In particular, we focus on oxidative stress in ageing, cancer and CV diseases, and we analyse the connections among CV risk factors, cancer and cardiotoxicity from anticancer drugs.

Risk factors associated with mammary tumors in female dogs

ABSTRACT: Mammary tumors in female dogs are the most frequent and corresponds to half of the canine tumors. The objectives of this study were to determine the risk factors associated with the occurrence of mammary tumors in female dogs and to evaluate the macroscopic characteristics of these neoformations, using 386 dogs from the “Outubro Rosa Pets” events done within the cities of Uberlândia and Patos de Minas, Minas Gerais State, Brazil, in 2015 (n=194), 2016 (n=105) and 2017 (n=87). For the determination of risk factors, the binary logistic regression test (P<0.05) was performed. The occurrence of mammary tumors was 23.6% (91/386). The significant risk factors identified were increased age (P<0.001), overweight (P=0.048) and non-castration (P<0.001) with a chance of, respectively, 1.6, 2.3 and 9.3 times for the development of mammary tumors. In dogs with mammary tumors (n=91), 153 lesions were present, of which 39 female dogs had two or more lesions (42.8%). Most of the lesions were at the caudal abdominal (M4) and inguinal (M5) mammary glands (60.13%, 92/153). Relative to the size of the lesions, it was observed that in 78% of the female dogs the lesions were determined asT1 (<3cm), 16.5% were T2 (3-5cm) and 5.5% T3 (>5cm). At least 15.4% (14/91) of the dogs had one of the regional lymph nodes increased. In conclusion, the occurrence of mammary tumors in the evaluated population was 23.6% and that age, overweight and non-realization of ovariohysterectomy are risk factors associated with the development of mammary tumors.

The role of obesity in inflammatory bowel disease

In just over a generation overweight and obesity has become a worldwide health concern. The ramifications for this on future health care costs and longevity are consequent, whilst increased adiposity is a harbinger for diabetes, kidney and bone failure, and cancer. An area of intense interest where the role of adiposity is avidly discussed is in inflammatory bowel disease (IBD), which presents mainly as Crohn's disease (CD) and ulcerative colitis (UC). Studies in patients associating IBD with a western diet are divergent. Nevertheless, elegant studies have found gene polymorphisms in humans that in murine models parallel the inflammatory and gut microbiome changes seen in IBD patients. However, an area not to be ignored are the alterations in adipocyte function with ensuing adiposity, in particular and a focus of this review, the dysregulation of the levels of adipocytokines such as leptin and adiponectin. Herein, we present and discuss the known influences of a western diet on IBD in patients and rodent models and how adipocytokines could influence the IBD disease process.

Immediate postoperative of bariatric surgery in the intensive care unit versus an inpatient unit. A retrospective study with 828 patients

Objective

To compare the incidence of complications and the duration of hospitalization of patients undergoing bariatric surgery admitted to the intensive care unit or a post-surgical hospitalization unit.

Methods

This retrospective observational study included 828 patients admitted between January 2010 and February 2015 during the immediate postoperative period of bariatric surgery in a hospital. Data were collected via electronic medical records. The Mann-Whitney test was used to compare continuous variables, and the chi-square was used to compare categorical variables.

Results

Patients in both groups had similar demographic characteristics, with no significant differences in anthropometric data and comorbidities. There was no significant difference in the comparison of complications between the two groups. However, the group admitted to the intensive care unit had longer hospitalization times (median of 3 days versus 2 days, p < 0.05), and hospital costs were 8% higher.

Conclusion

The present study found no benefit in the routine admittance of patients to the intensive care unit after undergoing bariatric surgery. This practice increased hospitalization time and hospital costs, which wasted resources. It is necessary to create objective criteria to identify patients requiring intensive care unit admission after bariatric surgery.

Signals from the Adipose Microenvironment and the Obesity-Cancer Link-A Systematic Review

Obesity and its associated metabolic dysregulation are established risk factors for many cancers. However, the biologic mechanisms underlying this relationship remain incompletely understood. Given the rising rates of both obesity and cancer worldwide, and the challenges for many people to lose excess adipose tissue, a systematic approach to identify potential molecular and metabolic targets is needed to develop effective mechanism-based strategies for the prevention and control of obesity-driven cancer. Epidemiologic, clinical, and preclinical data suggest that within the growth-promoting, proinflammatory microenvironment accompanying obesity, crosstalk between adipose tissue (comprised of adipocytes, macrophages and other cells) and cancer-prone cells may occur via obesity-associated hormones, cytokines, and other mediators that have been linked to increased cancer risk and/or progression. We report here a systematic review on the direct "crosstalk" between adipose tissue and carcinomas in humans. We identified 4,641 articles with n = 20 human clinical studies, which are summarized as: (i) breast (n = 7); (ii) colorectal (n = 4); (iii) esophageal (n = 2); (iv) esophageal/colorectal (n = 1); (v) endometrial (n = 1); (vi) prostate (n = 4); and (vii) ear-nose-throat (ENT) cancer (n = 1). Findings from these clinical studies reinforce preclinical data and suggest organ-dependent crosstalk between adipose tissue and carcinomas via VEGF, IL6, TNFα, and other mechanisms. Moreover, visceral white adipose tissue plays a more central role, as it is more bioenergetically active and is associated with a more procancer secretome than subcutaneous adipose tissue. Efforts to eavesdrop and ultimately interfere with this cancer-enhancing crosstalk may lead to new targets and strategies for decreasing the burden of obesity-related cancers. Cancer Prev Res; 10(9); 494-506. ©2017 AACR.

Pancreatic cancer screening: Still a delusion?

Pancreatic adenocarcinoma represents the fourth most common cause of cancer mortality and death due to pancreatic cancer (PC) have increased since 2003. Its incidence has also raised about 30% in the past decade and it is expected to become the second cause of cancer mortality by 2020 in the USA. Most PC present with metastatic disease and improvements in treatment outcomes for this group have been disappointing. These observations support the idea that screening to identify patients at an earlier stage might be an important strategy in improving overall PC outcomes. Many protocols have been tested, nevertheless, by now there is no effective screening program. Given the overall low incidence of disease and the current lack of accurate, inexpensive and noninvasive screening tests, the consensus is that widespread population-based screening for PC in the general population or in patients with only one affected first-degree relative is neither practicable nor indicated in most countries. However, a different scenario is screening patients with higher risk for PC, most of them with hereditary conditions predisposing the development of this neoplasia. In fact, some guidelines are now available helping to select these individuals at risk and to screen them, in order to achieve early detection of PC.

Does obesity cause chronic inflammation? The association between complete blood parameters with body mass index and fasting glucose

OBJECTIVE

This study aimed to determine the relationship of complete blood count (CBC) parameters and derivates with fasting blood sugar and the body mass index.

METHODS

This was a prospective, observational clinical study. Hospitalized patients who received a physiotherapy program in the Physical Medicine and Rehabilitation Clinic between March and June 2016 were included. The age, height, weight, body mass index (BMI), fasting blood glucose, erythrocyte sedimentation (ESR), C-reactive protein, and CBC parameters (leukocytes, platelets, neutrophil, lymphocytes, and monocytes) and red cell distribution width, platelet distribution width, neutrophil-lymphocyte ratio (NLR), and platelet-lymphocyte ratio of the patients were recorded. The relationship between the BMI, fasting glucose, and CBC parameters and derivates were investigated. Patients were divided into groups based on BMI: BMI≤25 kg/m², normal; BMI=26-30 kg/m², overweight; and BMI>30 kg/m², obese. A P value>0.005 was considered statistically significant.

RESULTS

A significant difference in the lymphocyte count, ESR, and NLR values was observed among the three groups (P=0.011; P=0.021; P=0.04). A significant difference in NLR was found between groups 1 and 3 (P=0.04). Between groups 1 and 3, a significant difference in platelet count was noted (P=0.013). On dividing the patients into two groups: normal and overweight/obese, a significant difference in lymphocyte count, glucose, and ESR values was observed (P=0.038; P=0.05; P=0.013). The lymphocyte count, ESR, and glucose values were found to be higher in the overweight group. According to Spearman's correlation analysis, the BMI and NLR values were found to be negatively correlated (P=0.029; r=.145); however, the lymphocyte count and ESR values were positively correlated (P=0.009; r=.173); (P=0.013; r=.182).

CONCLUSION

This study found a negative correlation between the NLR and BMI values and a lower NLR value in the obese group compared with the normal group. The overweight group showed a higher lymphocyte count, thereby confirming the positive correlation of lymphocyte count with BMI. A comprehensive clarification of the mechanisms underlying the relationship between obesity and inflammation may allow developing treatment strategies to reduce the negative effects of obesity.

Neck circumference as a screening measure of overweight/obesity among Indian adults

Neck circumference (NC) is an anthropometric measurement of differentiating body fat distributions and a marker of upper subcutaneous adiposity. The present study highlights the association and importance of NC as a suitable proxy screening measure of overweight/obesity as compared to the conventional anthropometric variables used among Indian adults. The present community based cross-sectional study was undertaken among 1169 Karbi adults (males: 625; females: 544) residing in Karbi Anglong district of Assam, Northeast India, who were selected through a multistage stratified random sampling method. Height, weight, waist circumference (WC), hip circumference (HC) and NC were recorded using standard procedures. The body mass index (BMI) was calculated and prevalence of overweight/obesity was assessed using standard cut-offs. The prevalence of obesity using BMI (≥25.00 kg m-2) was 15.52% and 15.26% among males and females, respectively (p≥0.05).The prevalence of obesity using NC was observed to be significantly higher among males (48.80%) than females (19.12%) (p<0.01). The binary logistic regression analysis showed that NC predicted obesity over the conventional anthropometric variables with reasonable accuracy (p<0.01). The ROC-AUC analysis showed a relatively greater significant association between BMI, WC and HC and NC for obesity (p<0.01). Thus, NC appears to be a potentially simple, easyto- use screening measure for predicting obesity among adults. Further studies are required to validate its use for screening of obesity among other ethnic populations in India.

Role of bile acids in carcinogenesis of pancreatic cancer: An old topic with new perspective

The role of bile acids in colorectal cancer has been well documented, but their role in pancreatic cancer remains unclear. In this review, we examined the risk factors of pancreatic cancer. We found that bile acids are associated with most of these factors. Alcohol intake, smoking, and a high-fat diet all lead to high secretion of bile acids, and bile acid metabolic dysfunction is a causal factor of gallstones. An increase in secretion of bile acids, in addition to a long common channel, may result in bile acid reflux into the pancreatic duct and to the epithelial cells or acinar cells, from which pancreatic adenocarcinoma is derived. The final pathophysiological process is pancreatitis, which promotes dedifferentiation of acinar cells into progenitor duct-like cells. Interestingly, bile acids act as regulatory molecules in metabolism, affecting adipose tissue distribution, insulin sensitivity and triglyceride metabolism. As a result, bile acids are associated with three risk factors of pancreatic cancer: obesity, diabetes and hypertriglyceridemia. In the second part of this review, we summarize several studies showing that bile acids act as cancer promoters in gastrointestinal cancer. However, more question are raised than have been solved, and further oncological and physiological experiments are needed to confirm the role of bile acids in pancreatic cancer carcinogenesis.