Obesity and cancer: at the crossroads of cellular metabolism and proliferation

The obesity-autophagy-cancer axis: Mechanistic insights and therapeutic perspectives

Autophagy, a self-degradative process vital for cellular homeostasis, plays a significant role in adipose tissue metabolism and tumorigenesis. This review aims to elucidate the complex interplay between autophagy, obesity, and cancer development, with a specific emphasis on how obesity-driven changes affect the regulation of autophagy and subsequent implications for cancer risk. The burgeoning epidemic of obesity underscores the relevance of this research, particularly given the established links between obesity, autophagy, and various cancers. Our exploration delves into hormonal influence, notably INS (insulin) and LEP (leptin), on obesity and autophagy interactions. Further, we draw attention to the latest findings on molecular factors linking obesity to cancer, including hormonal changes, altered metabolism, and secretory autophagy. We posit that targeting autophagy modulation may offer a potent therapeutic approach for obesity-associated cancer, pointing to promising advancements in nanocarrier-based targeted therapies for autophagy modulation. However, we also recognize the challenges inherent to these approaches, particularly concerning their precision, control, and the dual roles autophagy can play in cancer. Future research directions include identifying novel biomarkers, refining targeted therapies, and harmonizing these approaches with precision medicine principles, thereby contributing to a more personalized, effective treatment paradigm for obesity-mediated cancer.

Pathological Remodeling of the Gut Barrier as a Prodromal Event of High-Fat Diet-Induced Obesity

Intestinal barrier alterations represent a primum movens in obesity and related intestinal dysfunctions. However, whether gut barrier remodeling represents prodromal events in obesity before weight gain, metabolic alterations, and systemic inflammation remains unclear. Herein, we examined morphologic changes in the gut barrier in a mouse model of high-fat diet (HFD) since the earliest phases of diet assumption. C57BL/6J mice were fed with standard diet (SD) or HFD for 1, 2, 4, or 8 weeks. Remodeling of intestinal epithelial barrier, inflammatory infiltrate, and collagen deposition in the colonic wall was assessed by histochemistry and immunofluorescence analysis. Obese mice displayed increased body and epididymal fat weight along with increased plasma resistin, IL-1β, and IL-6 levels after 8 weeks of HFD. Starting from 1 week of HFD, mice displayed (1) a decreased claudin-1 expression in lining epithelial cells, (2) an altered mucus in goblet cells, (3) an increase in proliferating epithelial cells in colonic crypts, (4) eosinophil infiltration along with an increase in vascular P-selectin, and (5) deposition of collagen fibers. HFD intake is associated with morphologic changes in the large bowel at mucosal and submucosal levels. In particular, the main changes include alterations in the mucous layer and intestinal epithelial barrier integrity and activation of mucosal defense-enhanced fibrotic deposition. These changes represent early events occurring before the development of obesity condition that could contribute to compromising the intestinal mucosal barrier and functions, opening the way for systemic dissemination.

Obesity and renal cell carcinoma: Biological mechanisms and perspectives

Obesity, defined by body mass index (BMI), is an established risk factor for specific renal cell carcinoma (RCC) subtypes such as clear cell RCC, the most common RCC histology. Many studies have identified an association between obesity and improved survival after diagnosis of RCC, a potential "obesity paradox." Clinically, there is uncertainty whether improved outcomes observed after diagnosis are driven by stage, type of treatment received, or artifacts of longitudinal changes in weight and body composition. The biological mechanisms underlying obesity's influence on RCC are not fully established, but multiomic and mechanistic studies suggest an impact on tumor metabolism, particularly fatty acid metabolism, angiogenesis, and peritumoral inflammation, which are known to be key biological hallmarks of clear cell RCC. Conversely, high-intensity exercise associated with increased muscle mass may be a risk factor for renal medullary carcinoma, a rare RCC subtype that predominantly occurs in individuals with sickle hemoglobinopathies. Herein, we highlight methodologic challenges associated with studying the influence of obesity on RCC and review the clinical evidence and potential underlying mechanisms associating RCC with BMI and body composition.

Seminars in immunology special issue: Nutrition, microbiota and immunity The unexplored microbes in health and disease

Functional characterization of the microbiome's influence on host physiology has been dominated by a few characteristic example strains that have been studied in detail. However, the extensive development of methods for high-throughput bacterial isolation and culture over the past decade is enabling functional characterization of the broader microbiota that may impact human health. Characterizing the understudied majority of human microbes and expanding our functional understanding of the diversity of the gut microbiota could enable new insights into diseases with unknown etiology, provide disease-predictive microbiome signatures, and advance microbial therapeutics. We summarize high-throughput culture-dependent platforms for characterizing bacterial strain function and host-interactions. We elaborate on the importance of these technologies in facilitating mechanistic studies of previously unexplored microbes, highlight new opportunities for large-scale in vitro screens of host-relevant microbial functions, and discuss the potential translational applications for microbiome science.

Cancer and Obesity: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) provides an overview of cancer and increased body fat.

Methods

The scientific information for this CPS is based upon published scientific citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

Topics include the increased risk of cancers among patients with obesity, cancer risk factor population-attributable fractions, genetic and epigenetic links between obesity and cancer, adiposopathic and mechanistic processes accounting for increased cancer risk among patients with obesity, the role of oxidative stress, and obesity-related cancers based upon Mendelian randomization and observational studies. Other topics include nutritional and physical activity principles for patients with obesity who either have cancer or are at risk for cancer, and preventive care as it relates to cancer and obesity.

Conclusions

Obesity is the second most common preventable cause of cancer and may be the most common preventable cause of cancer among nonsmokers. This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) on cancer is one of a series of OMA CPSs designed to assist clinicians in the care of patients with the disease of obesity. Patients with obesity are at greater risk of developing certain types of cancers, and treatment of obesity may influence the risk, onset, progression, and recurrence of cancer in patients with obesity.

Can the Irisin be a Biomarker for Prostate Cancer? A Case Control Study

Aim:

There is much evidence of an association between cancer and irisin that is an adipokine. This study researched on the relationship between prostate cancer (PCa) and irisin levels, and whether irisin can be used as a biomarker in the diagnosis of PCa.

Materials and Methods:

For the study groups, 50 primary PCa patients and 30 healthy male subjects were included in the PCa and healthy control groups, respectively. All volunteers in the healthy control group were screened for prostate cancer and other malignancies and chronic diseases. Volunteers who were determine to be completely healthy were included for healthy control group. In the serum samples of the subjects were measured free PSA, total PSA and irisin levels. Irisin levels were compared separately in terms of the Gleason scores and T stage. In addition to intergroup comparisons, the ROC curve for the irisin was plotted and power analysis was performed.

Results:

Free and total PSA levels in the PCa group were significantly higher compared to the healthy control group (p<0.05). In addition, irisin levels in the PCa group were significantly lower than in the healthy control group (p<0.05). There was no significant difference between irisin levels in the groups classified in terms of Gleason scores (p>0.05). When the cut-off value was taken as 8.1, the sensitivity and specificity of irisin for PCa were as 80.5% and 90%, respectively.

Conclusion:

The results of this study indicate that the levels of irisin in the PCa group are considerably reduced and irisin may be used as a biomarker as well as free and total PSA.

Bariatric Surgery in China: How Is This New Concept Going?

BACKGROUND

Obesity has become an epidemic in developing countries including China. The use of bariatric surgery to treat obesity has grown in popularity worldwide, but it is still a new concept in China. This study aims to investigate the trends in bariatric surgery in China.

METHODS

An electronic search of the MEDLINE, EMBASE, and Chinese National Knowledge Infrastructure was conducted to select studies for this survey.

RESULTS

A total of 7779 bariatric procedures were reported from 2001 to 2015, most of which (89.2 %) were performed in the most recent 5 years. Further, 70.9 % of all procedures were performed to treat obesity and related comorbidities, defined as metabolic surgery. The data showed 89.4 % of all operations were performed laparoscopically. The absolute number of bariatric surgeries increased 148.7 times in the last 5 years compared to the 2001-2005 period. The percentage of laparoscopic Roux-en-Y gastric bypasses performed increased from 0 to 62.2 %, and the percentage of laparoscopic sleeve gastrectomies from 0 to 12.7 %. The percentage of laparoscopic adjustable gastric bands increased dramatically from 0 to 73.3 % in the 2006-2010 period, but it dropped quickly to 12.9 % in the 2011-2015 period. Most operations (66.7 %) were conducted in the East area, which is the most developed economic region in China. There was limited surgical innovation or original research reported in China.

CONCLUSIONS

Bariatric surgery is still at an early stage in China, but is now experiencing an explosive growth. A national registry system needs to be established to record and provide precise data.

Young Adult Risk Factors for Cancer: Obesity, Inflammation, and Sociobehavioral Mechanisms

INTRODUCTION

The paper assesses social disparities in the burdens of metabolic and inflammatory risks for cancer in the U.S. young adult population and examines psychosocial and behavioral mechanisms in such disparities.

METHODS

Using data of 7,889 individuals aged 12-32 years from the National Longitudinal Study of Adolescent to Adult Health from 1994 to 2009, generalized linear models were used to assess the sex, race/ethnicity, and SES differences in the risks of obesity and inflammation, measured by C-reactive protein. Further tests examined the extent to which social isolation, smoking, physical inactivity, alcohol abuse, and illicit drug use explain social differentials in each biomarker outcome.

RESULTS

Women, blacks, Hispanics, and socioeconomically disadvantaged groups had higher risks of obesity and elevated C-reactive protein, with the SES gradients being more pronounced in female participants. Health-related behaviors showed large variation across sex, race, and SES strata. After adjusting for these behavioral variables, sex, and race disparities in obesity and excess inflammation in blacks diminished, whereas the adolescent SES disparity in obesity remained. The associations of adolescent and young adult SES disadvantage and inflammation were also explained by behavioral mechanisms. Behavioral factors associated with higher risks of obesity and inflammation differed, with the exception of fast food consumption, a risk factor for both.

CONCLUSIONS

This study provides new knowledge of social distribution of early life exposures to physiologic precedents to cancer development later in life with implications for prevention and early intervention of modifiable risky behaviors in adolescents and young adults.

miRNAs in nutrition, obesity, and cancer: The biology of miRNAs in metabolic disorders and its relationship with cancer development

SCOPE

The scope of this review is to explain how metabolic disorders originated by a deficient nutrition can develop into a neoplastic process by the alteration of epigenetic mechanisms like miRNAs. Obesity is a proinflammatory state with a wide impact on health around the world that is associated with neoplastic diseases. Epigenetic mechanisms have a central role in the obesogenic environment, which participates on the development of comorbidities such as cancer.

METHODS AND RESULTS

We made an exhaustive review of the most recent reports about metabolic disorders with nutrition and their relationship with miRNAs, and their risk of developing into oncogenic processes. MicroRNAs (miRNAs) act as one of the major epigenetic mechanisms that can affect the metabolic reprogramming of cellular metabolism that plays an important role in the oncogenic process. There is evidence that some foods may contribute to diminishing the risk of cancer as well as epidemiological studies that support the notion that diets high in animal protein and fat promote cancer risk. Therefore, diets high in fruit and vegetables reduce the risk of cancer. One of the principal explanations is that these foods contain bioactive compounds that increase the efficacy of epigenetic mechanisms, which in turn decrease the risk of obesity and its comorbidities.

CONCLUSION

In this review, we show how miRNAs are implicated in several signaling pathways as well as illustrating some bioactive compounds that impact inflammation and cancer development.

Trends of bariatric surgery in France during the last 10 years: analysis of 267,466 procedures from 2005-2014

BACKGROUND

During the past decade, the field of bariatric surgery has changed dramatically.

OBJECTIVES

The study aims to summarize and perform a periodic assessment of the current trends in the use of bariatric surgery in France and review findings on the long-term progression of bariatric surgery. The data were extracted from the national registry Programme de Médicalisation des Systèmes d׳Information from 2005 to 2014.

SETTING

National health system and private practice in France.

METHODS

We identified all hospitalizations during which a bariatric procedure was performed for the treatment of morbid obesity from 2005 to 2014 in France. Data were reviewed for patient characteristics and the number and types of bariatric procedures. We also analyzed the setting and the characteristics of the centers and the difference of the activity between the public and private sector.

RESULTS

Between 2005 and 2014, the number of bariatric operations increased fourfold. Sleeve gastrectomy became the most performed bariatric intervention, representing 60.7% of bariatric activity in 2014. There was a concomitant steep increase in sleeve gastrectomy, with Roux-en-Y gastric bypass increasing slightly overall and a substantial decrease in adjustable gastric banding. In 2014, 481 centers performed bariatric surgery. Among them, one third performed<30 operations/yr. We observed an overall in-hospital mortality ranging from .038% to .05% during the last 3 years.

CONCLUSION

Bariatric surgery is increasing in France, with a fourfold augmentation of interventions in the last 10 years. The number of sleeve gastrectomies has increased considerably. This activity is performed in numerous centers, one third of them performing<30 interventions/yr.

Obesity-associated cancer: an immunological perspective

Epidemiological studies have established an association between obesity, insulin resistance, type 2 diabetes and a number of cancer types. Research has focused predominantly on altered endocrine factors, growth factors and signalling pathways, with little known in man about the immune involvement in the relevant pathophysiological processes. Moreover, in an era of exciting new breakthroughs in cancer immunotherapy, there is also a need to study the safety and efficacy of immunotherapeutics in the complex setting of inflammatory-driven obesity-associated cancer. This review addresses key immune cell subsets underpinning obesity-associated inflammation and describes how such immune compartments might be targeted to prevent and treat obesity-associated cancer. We propose that the modulation, metabolism, migration and abundance of pro- and anti-inflammatory cells and tumour-specific T cells might be therapeutically altered to both restore immune balance, alleviating pathological inflammation, and to improve anti-tumour immune responses in obesity-associated cancer.

Cancer and the microbiota

A host's microbiota may increase, diminish, or have no effect at all on cancer susceptibility. Assigning causal roles in cancer to specific microbes and microbiotas, unraveling host-microbiota interactions with environmental factors in carcinogenesis, and exploiting such knowledge for cancer diagnosis and treatment are areas of intensive interest. This Review considers how microbes and the microbiota may amplify or mitigate carcinogenesis, responsiveness to cancer therapeutics, and cancer-associated complications.