Linkage Between Obesity Leptin and Breast Cancer

The potential role of targeting the leptin receptor as a treatment for breast cancer in the context of hyperleptinemia: a literature review

Since cancer is becoming a leading cause of death worldwide, efforts should be concentrated on understanding its underlying biological alterations that would be utilized in disease management, especially prevention strategies. Within this context, multiple bodies of evidence have highlighted leptin's practical and promising role, a peptide hormone extracted from adipose and fatty tissues with other adipokines, in promoting the proliferation, migration, and metastatic invasion of breast carcinoma cells. Excessive blood leptin levels and hyperleptinemia increase body fat content and stimulate appetite. Also, high leptin level is believed to be associated with several conditions, including overeating, emotional stress, inflammation, obesity, and gestational diabetes. It has been noted that when leptin has impaired signaling in CNS, causing the lack of its normal function in energy balance, it results in leptin resistance, leading to a rise in its concentration in peripheral tissues. Our research paper will shed highlighting on potentially targeting the leptin receptor and its cellular signaling in suppressing breast cancer progression.

Consumption of Sugar Sweetened Beverages (SSBs) and Breast Cancer: A Narrative Review

Sugar sweetened beverages (SSBs) have become a cause of concern because of their growing consumption levels across age groups and associated chronic diseases such as diabetes mellitus, cardiovascular diseases and cancers. The aim of this review was to provide a detailed profile of the SSBs trends and associated health risk, with special focus on its role in breast cancer development. A review of current literature has depicted increased in-takes of SSBs across the globe with servings ranging from 3 to 11 per day in different countries, while children, adolescents and young adults report the highest intake levels. These increased intakes further contribute to different metabolic diseases via increased body adiposity, blood glucose and insulin levels, and increased post-menopausal estrogen levels, all of which contribute to chronic diseases, including cancers. Nutrition interventions including ones that target SSBs reduction seem to have a positive impact on reducing the development of these non-communicable diseases and are also associated with better prognosis and survival chances in cancer patients. However, the implementation of SSBs taxation and mass awareness campaign interventions remains poor due to lack of policy development and regulation for these beverages. The control of SSBs intake across the world requires rigorous research to construct efficient and practical policies to reduce the accessibility and marketing of SSBs while simultaneously increasing awareness in the public regarding the health risks of these beverages. To achieve this, a coordinated approach involving different public and private sectors is needed.

Breast cancer shares many epidemiological, lifestyle, and local hormonal and metabolic underpinnings with endometrial and ovarian cancer: a narrative review

Background and Objective

Breast, endometrial, and ovarian cancers (OCs) are significant public health concerns. Approximately three million patients are diagnosed with one of the three tumor types annually. The three tumor types exhibit related epidemiological trends, lifestyle risk factors, and tumor-specific characteristics which may influence their incidence and outcomes. While the majority of the literature examining hormone dependence of cancer appropriately is centered around breast cancer (BC), insufficient attention has been paid to how lessons from the biology of endometrial and OC may inform what we know about the biology of BC and vice versa. This narrative review seeks to address that unmet need.

Methods

The construction of this narrative review involved searching PubMed in April and July 2024 for manuscripts related to breast cancer metabolism, ovarian cancer metabolism, and endometrial cancer metabolism. Only manuscripts written in English were considered.

Key Content and Findings

This narrative review discusses epidemiologic, systemic, and local factors that may affect breast, endometrial, and OC. Simultaneously analyzing these three tumors offers an opportunity to gain unifying insights into reproductive hormone-dependent cancer biology; unfortunately, the field lacks studies directly comparing the impact of the aforementioned factors on these three tumor types. Therefore, we are limited to comparing the impact of similar systemic factors on tumor progression in each tumor type.

Conclusions

There is some convergence of systemic metabolic changes, particularly with regard to factors associated with obesity, on the biology of breast, ovarian, and endometrial cancer. However, future research is needed in order to clarify the convergent-or potentially divergent-mechanism(s) by which obesity affects breast, endometrial and OC.

Influence of Type 2 Diabetes and Adipose Tissue Dysfunction on Breast Cancer and Potential Benefits from Nutraceuticals Inducible in Microalgae

Breast cancer (BC) represents the most prevalent cancer in women at any age after puberty. From a pathogenetic prospective, despite a wide array of risk factors being identified thus far, poor metabolic health is emerging as a putative risk factor for BC. In particular, type 2 diabetes mellitus (T2DM) provides a perfect example bridging the gap between poor metabolic health and BC risk. Indeed, T2DM is preceded by a status of hyperinsulinemia and is characterised by hyperglycaemia, with both factors representing potential contributors to BC onset and progression. Additionally, the aberrant secretome of the dysfunctional, hypertrophic adipocytes, typical of obesity, characterised by pro-inflammatory mediators, is a shared pathogenetic factor between T2DM and BC. In this review, we provide an overview on the effects of hyperglycaemia and hyperinsulinemia, hallmarks of type 2 diabetes mellitus, on breast cancer risk, progression, treatment and prognosis. Furthermore, we dissect the role of the adipose-tissue-secreted adipokines as additional players in the pathogenesis of BC. Finally, we focus on microalgae as a novel superfood and a source of nutraceuticals able to mitigate BC risk by improving metabolic health and targeting cellular pathways, which are disrupted in the context of T2DM and obesity.

Obesity and Early-Onset Breast Cancer and Specific Molecular Subtype Diagnosis in Black and White Women: NIMHD Social Epigenomics Program

Importance

Epidemiologic data suggest an association of obesity with breast cancer (BC); however, obesity's contribution to early onset and risk of diagnosis with specific molecular subtypes by race is uncertain.

Objective

To examine the race-specific association of body mass index with early onset and diagnosis of specific molecular subtypes.

Design, Setting, and Participants

This retrospective cohort study included patients with BC diagnosed between October 1, 2017, and March 31, 2022, at 3 University of South Alabama Mitchell Cancer Institute clinics. Participants were also prospectively enrolled for serum leptin measurement.

Main Outcomes and Measures

The primary outcome was age at BC onset and specific subtype diagnosis. The secondary outcome was race-specific differences. Odds ratios (ORs) for associations of body mass index with age at onset and subtype were estimated using the Fisher exact test. Race was self-reported.

Results

Of the 1085 study patients, 332 (30.6%) were Black with a median age of 58 (IQR, 50-66) years, and 753 (69.4%) were White with a median age of 63 (IQR, 53-71) years. A total of 499 patients (46.0%) had obesity, with Black women with obesity receiving more frequent BC diagnosis than their White counterparts (OR, 2.40; 95% CI, 1.87-3.15; P < .001). In addition, Black women had a significantly higher incidence of early-onset disease (OR, 1.95; 95% CI, 1.33-2.86; P = .001) than White women, and obesity increased this risk significantly in Black women (OR, 2.92; 95% CI, 1.35-6.22; P = .006). Black women with obesity also had a significantly higher risk of luminal A BC (OR, 2.53; 95% CI, 1.81-3.56; P < .001) and triple-negative BC (TNBC) (OR, 2.48; 95% CI, 1.43-4.22; P = .002) diagnosis than White counterparts. Black women, with or without BC, had significantly higher serum leptin levels (median [IQR], 55.3 [40.3-66.2] ng/mL and 29.1 [21.1-46.5] ng/mL, respectively, P < .001) than White women (median [IQR], 33.4 [18.9-47.7] ng/mL and 16.5 [10.0-22.9] ng/mL, respectively), which was associated with higher odds of luminal A disease (OR, 5.25; 95% CI, 1.69-14.32, P = .003). Higher odds of early-onset disease (OR, 3.50; 95% CI, 0.43-23.15; P = .33 for trend), and TNBC diagnosis (OR, 6.00; 95% CI, 0.83-37.27; P = .14 for trend) were also seen, although these outcomes were not statistically significant.

Conclusions and Relevance

In this cohort study of patients with BC, obesity and high serum leptin levels were associated with an enhanced risk of early-onset BC and diagnosis of luminal A and TNBC subtypes in Black women. These findings should help in developing strategies to narrow the existing disparity gaps.

Long-Term High-Fat Diet Limits the Protective Effect of Spontaneous Physical Activity on Mammary Carcinogenesis

Breast cancer is influenced by factors such as diet, a sedentary lifestyle, obesity, and postmenopausal status, which are all linked to prolonged hormonal and inflammatory exposure. Physical activity offers protection against breast cancer by modulating hormones, immune responses, and oxidative defenses. This study aimed to assess how a prolonged high-fat diet (HFD) affects the effectiveness of physical activity in preventing and managing mammary tumorigenesis. Ovariectomised C57BL/6 mice were provided with an enriched environment to induce spontaneous physical activity while being fed HFD. After 44 days (short-term, ST HFD) or 88 days (long-term, LT HFD), syngenic EO771 cells were implanted into mammary glands, and tumour growth was monitored until sacrifice. Despite similar physical activity and food intake, the LT HFD group exhibited higher visceral adipose tissue mass and reduced skeletal muscle mass. In the tumour microenvironment, the LT HFD group showed decreased NK cells and TCD8+ cells, with a trend toward increased T regulatory cells, leading to a collapse of the T8/Treg ratio. Additionally, the LT HFD group displayed decreased tumour triglyceride content and altered enzyme activities indicative of oxidative stress. Prolonged exposure to HFD was associated with tumour growth despite elevated physical activity, promoting a tolerogenic tumour microenvironment. Future studies should explore inter-organ exchanges between tumour and tissues.

The Link between Obesity and Gastrointestinal Cancers: a Short Review

Gastrointestinal cancer represents one of the most encountered oncologic pathologies and research studies are performed thoroughly in order to identify the exact causes and possible novel therapies. Obesity is a complex manifestation associated with numerous physiological and primarily molecular changes capable of tackling the behavior of tumoral cells and the nearby or faraway microenvironment. Adipose tissue has been once considered to have limited physiological roles, but in recent years it has been recognized as an active endocrine organ, secreting substances such as growth factors and adipokines. From an epidemiological perspective, obesity - particularly morbid obesity - is linked to an unfavorable progression of cancer. A key mechanism that may elucidate the association between obesity and cancer involves the insulin and insulin-like growth factor (IGF-1) pathway, sex hormones, and adipokines.

Combined Aerobic and Resistance Training Improves Body Composition, Alters Cardiometabolic Risk, and Ameliorates Cancer-Related Indicators in Breast Cancer Patients and Survivors with Overweight/Obesity: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Breast cancer survivors with obesity are at a high risk of cancer recurrence, comorbidity, and mortality. This review aims to systematically evaluate the effects of combined aerobic and resistance training (CART) on body composition, lipid homeostasis, inflammation, adipokines, cancer-related fatigue, sleep, and quality of life in breast cancer patients and survivors with overweight/obesity. An electronic search was conducted in PubMed, Web of Science, Scopus, Science Direct, Cochrane, and Google Scholar databases from inception up to January 8, 2024. Randomized controlled trials (RCTs) meeting the inclusion criteria were selected for the analysis. The Cochrane risk of bias tool was used to assess eligible studies, and the GRADE method to evaluate the quality of evidence. A random-effects model was used, and data were analyzed using mean (MD) and standardized mean differences (SMD) for continuous variables with 95% confidence intervals (CI). We assessed the data for risk of bias, heterogeneity, sensitivity, reporting bias, and quality of evidence. A total of 17 randomized controlled trials were included in the systematic review involving 1,148 female patients and survivors (mean age: 54.0 ± 3.4 years). The primary outcomes showed significant improvements in body mass index (SMD -0.57 kg/m2, p = 0.04), body fat (SMD -0.50%, p = 0.02), fat mass (SMD -0.63 kg, p = 0.04), hip circumference (MD -3.14 cm, p = 0.02), and fat-free mass (SMD 1.03 kg, p < 0.001). The secondary outcomes indicated significant increases in high-density lipoprotein cholesterol (MD -0.05 mmol/L, p = 0.008), natural killer cells (SMD 0.42%, p = 0.04), reductions in triglycerides (MD -81.90 mg/dL, p < 0.01), total cholesterol (SMD -0.95 mmol/L, p < 0.01), tumor necrosis factor α (SMD -0.89 pg/mL, p = 0.03), and leptin (SMD -0.63 ng/mL, p = 0.03). Also, beneficial alterations were found in cancer-related fatigue (SMD -0.98, p = 0.03), sleep (SMD -1.17, p < 0.001), and quality of life (SMD 2.94, p = 0.02) scores. There was very low to low confidence in the estimated effect of most of the outcomes. The present findings reveal that CART could be considered an adjunct therapy in supporting the conventional clinical approach observed following exercise. However, further high-quality research is needed to evaluate whether CART would be a valuable intervention to lower aggressive pharmacologic use in breast cancer patients with overweight/obesity.

Association of leptin receptor polymorphisms with susceptibility of non-small cell lung cancer: Evidence from 2249 subjects

Non-small cell lung cancer (NSCLC) is increasing dramatically. It is believed that energy metabolism-related genes could play an important role in etiology of NSCLC. In this study, we sought to assess the correlation between three LEPR single nucleotide polymorphisms (rs1137101, rs1137100 and rs6588147) with NSCLS susceptibility. In total, 1193 NSCLC cases and 1056 controls were included. SNPscan™ genotyping method was used to analyze the genotypes of LEPR polymorphisms. Compared to rs6588147 GG in LEPR gene, this study identified a protective role of LEPR rs6588147 GA and GA/AA for the occurrence of NSCLC (GA vs. GG [p = 0.021] and GA/AA vs. GG [p = 0.030]). As well, we found that a protective role of LEPR rs6588147 for the occurrence of non-SCC subgroup (p < 0.05). By logistic regression analysis, we found that the rs6588147 A allele related genotypes might play a protective role for the occurrence of NSCLC in drinking, BMI ≥24 kg/m2, smoking and male subgroups. We also found that the rs1137101 A allele related genotypes played a protective role for the occurrence of NSCLC in male, younger participants (under 59 years) and overweight/obesity (BMI ≥24 kg/m2) subgroups. We found that LEPR Ars1037100Ars1037101Ars6588147 haplotype might play a protective role for the occurrence of NSCLC (p = 0.013). In addition, our findings indicated that LEPR rs1137100 G>A SNP might increase the risk of lymph node metastases (p = 0.038). This study highlights that LEPR rs6588147, rs1137101 genotypes and LEPR Ars1037100Ars1037101Ars6588147 haplotype are correlated with the occurrence of NSCLC. LEPR rs1137100 G>A SNP increases the risk of lymph node metastases.

Bariatric Surgery and Longitudinal Cancer Risk: A Review

Importance

Cancer is one of the leading causes of death in the United States, with the obesity epidemic contributing to its steady increase every year. Recent cohort studies find an association between bariatric surgery and reduced longitudinal cancer risk, but with heterogeneous findings.

Observations

This review summarizes how obesity leads to an increased risk of developing cancer and synthesizes current evidence behind the potential for bariatric surgery to reduce longitudinal cancer risk. Overall, bariatric surgery appears to have the strongest and most consistent association with decreased incidence of developing breast, ovarian, and endometrial cancers. The association of bariatric surgery and the development of esophageal, gastric, liver, and pancreas cancer is heterogenous with studies showing either no association or decreased longitudinal incidences. Conversely, there have been preclinical and cohort studies implying an increased risk of developing colon and rectal cancer after bariatric surgery. A review and synthesis of the existing literature reveals epidemiologic shortcomings of cohort studies that potentially explain incongruencies observed between studies.

Conclusions and Relevance

Studies examining the association of bariatric surgery and longitudinal cancer risk remain heterogeneous and could be explained by certain epidemiologic considerations. This review provides a framework to better define subgroups of patients at higher risk of developing cancer who would potentially benefit more from bariatric surgery, as well as subgroups where more caution should be exercised.

Association of physical weight statuses defined by body mass index (BMI) with molecular subtypes of premenopausal breast cancer: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

The association between overweight/obesity and postmenopausal breast cancer has been proven. However, uncertainty exists regarding the association between physical weight statuses and premenopausal breast cancer subtypes. This study aimed to explore the association of body weight statuses with molecular subtypes of premenopausal breast cancer.

METHOD

A systematic search of Medline, PubMed, Embase, and Web of Science was performed. The Newcastle-Ottawa Scale (NOS) and the Joanna Briggs Institute (JBI) Critical Appraisal tools were used to evaluate the quality of the literature. STATA and R software were used to analyze the extracted data.

RESULT

The meta-analysis included 35 observational studies with a total of 41,049 premenopausal breast cancer patients. The study showed that the proportion of underweight patients was 4.8% (95% CI = 3.9-5.8%, P = 0.01), overweight was 29% (95%CI = 27.1-30.9%, P < 0.01), obesity was 17.8% (95% CI = 14.9-21.2%, P < 0.0001), and normal weight was 51.6% (95% CI = 46.7-56.5%, P < 0.0001). The pooled results showed that in comparison to the normal weight group, being physically underweight is related to a 1.44-fold risk (OR = 1.44, 95%CI = 1.28-1.63, P < 0.0001) of HER2 + breast cancer. Overweight is related to a 1.16-fold risk (OR = 1.16, 95%CI = 1.06-1.26, P = 0.002) of TNBC and a 16% lower risk (OR = 0.84, 95%CI = 0.75-0.93, P = 0.001) of ER + breast cancer. When compared to underweight/normal weight populations, both overweight (OR = 0.74, 95%CI = 0.56-0.97, P = 0.032) and obesity (OR = 0.70, 95%CI = 0.50-0.98, P = 0.037) can reduce the risk of ER + PR + breast cancer.

CONCLUSION

In the premenopausal breast cancer population, the distribution of patients' numbers with different weight statuses was significantly distinct among the various breast cancer subtypes. Additionally, the associations between physical weight statuses and the risk of premenopausal breast cancer subtypes are divergent.

The Role of Adipokines in Tumor Progression and Its Association with Obesity

Obesity is a well-established risk factor for various malignancies and emerging evidence suggests that adipokines play a pivotal role in linking excess adiposity to tumorigenesis. Adipokines are bioactive molecules secreted by adipose tissue and their altered expression in obesity contributes to a pro-inflammatory, pro-angiogenic, and growth-promoting microenvironment conducive to tumorigenesis. Leptin, a key adipokine, activates survival and proliferative signaling pathways whereas adiponectin exhibits tumor-suppressive effects by inducing apoptosis and cell cycle arrest. Visfatin has also been documented to promote tumor growth, angiogenesis, migration, and invasion. Moreover, emerging studies suggest that adipokines, such as resistin, apelin, and chemerin, which are overexpressed in obesity, may also possess oncogenic functions. Despite advancements in our understanding of the roles of individual adipokines in cancer, the intricate interplay and crosstalk between adipokines, tumor cells, and the tumor microenvironment remain complex and multifaceted. This review highlights the evolving knowledge of how adipokines contribute to obesity-related tumorigenesis, shedding light on the potential of targeting adipokine signaling pathways as a novel therapeutic approach for obesity-associated cancers. Further research on the specific mechanisms and interactions between adipokines and tumor cells is crucial for a comprehensive understanding of obesity-associated cancer pathogenesis.

Association between leptin receptor polymorphisms and polycystic ovary syndrome risk: a meta-analysis based on 11 studies

OBJECTIVE

Published evidence indicated that the leptin receptor (LEPR) gene polymorphisms are associated with polycystic ovary syndrome (PCOS) risk. However, studies on the association between the polymorphisms of LEPR gene are inconsistent or even controversial.

MATERIAL AND METHODS

We conducted this meta-analysis to explore the more precise relationship between LEPR polymorphisms and PCOS risk. Relevant articles were searched with five online databases up to March 1 2023. Odds ratios (OR) with 95% confidence intervals (CI) were selected to examine the statistical strength of each genetic model. Moreover, RNA secondary structure and variant effects of these loci were examined with in silico analysis.

RESULTS

Overall, 11 publications were analyzed, and the pooled results did not present any significant association between rs1137101 A/G polymorphism and PCOS risk in general population and some subgroup analysis. But the significant association were observed in Asian population (AG vs. AA: OR = 0.51, 95%CI = 0.32-0.81, p = .01, I2=0%; AG + GG vs. AA: OR = 0.41, 95%CI = 0.26-0.65, p < .01, I2=25.9%). Moreover, similar positive associations were also observed in rs1805096 polymorphism with PCOS risk.

CONCLUSION

In summary, our meta-analysis suggested that the LEPR gene polymorphisms might be associated with PCOS susceptibility. Owing to the limited studies and small sample size in our meta-analysis, more well-designed studies from different races were needed to be conducted to verify the current results.

High-intensity interval training in breast cancer patients: A systematic review and meta-analysis

BACKGROUND

Women with breast cancer and improved survival often experience treatment-related impairments. High-intensity interval training (HIIT) has emerged as a promising exercise therapy modality for adult cancer patients. However, the overall effects of HIIT in breast cancer patients remain scarce and controversial. Therefore, we conducted a systematic review and meta-analysis to comprehensively evaluate the impact of HIIT on health-related outcomes in breast cancer patients.

METHODS

We searched the PubMed, Embase, and Web of Science from inception to November 7, 2022. Eligible studies included randomized controlled trials that compared HIIT interventions with usual care (UC) or MICT in breast cancer patients. The primary outcome assessed was physical fitness, and exploratory outcomes included body composition, blood-borne biomarkers, and patient-reported outcomes. Summary data were extracted, and standardized mean differences (SMD) were calculated for meta-analysis. For outcomes that could not be pooled, a systematic review was conducted.

RESULTS

Our analysis included 19 articles from 10 studies, encompassing 532 participants who met the inclusion criteria. Pooled results demonstrated that HIIT was superior to UC in improving peak oxygen uptake (VO2peak ). The SMD for VO2peak (L/min) and VO2peak (mL/kg/min) was 0.79 (95% CI 0.13, 1.45) and 0.59 (95% CI 0.01, 1.16), respectively. No significant differences in VO2peak were found between the HIIT and MICT groups. Meta-analyses on body composition and blood-borne biomarkers showed no significant differences between HIIT and UC. Systematic review indicated favorable effects of HIIT on muscle strength, fatigue, and emotional well-being.

CONCLUSIONS

HIIT is a time-efficient alternative to MICT for improving VO2peak and may also enhance muscle strength and alleviate fatigue and emotional symptoms in breast cancer patients. HIIT should be considered as an important component of exercise prescription in breast cancer care. Further studies with larger cohorts are needed to determine the clinical significance of HIIT-induced changes in terms of other outcomes in women with breast cancer.

Bioinformatics and network biology approach to identifying type 2 diabetes genes and pathways that influence the progression of breast cancer

Breast cancer is the second most prevalent malignancy affecting women. Postmenopausal women breast tumor is one of the top causes of death in women, accounting for 23% of cancer cases. Type 2 diabetes, a worldwide pandemic, has been connected to a heightened risk of several malignancies, although its association with breast cancer is still uncertain. In comparison to non-diabetic women, women with T2DM had a 23% elevated likelihood of developing breast cancer. It is difficult to determine causative or genetic susceptibility that connect T2DM and breast cancer. We created a large-scale network-based quantitative approach employing unbiased methods to discover abnormally amplified genes in both T2DM and breast cancer, to solve these issues. We performed transcriptome analysis to uncover identical genetic biomarkers and pathways to clarify the connection between T2DM and breast cancer patients. In this study, two RNA-seq datasets (GSE103001 and GSE86468) from the Gene Expression Omnibus (GEO) are used to identify mutually differentially expressed genes (DEGs) for breast cancer and T2DM, as well as common pathways and prospective medicines. Firstly, 45 shared genes (30 upregulated and 15 downregulated) between T2D and breast cancer were detected. We employed gene ontology and pathway enrichment to characterize prevalent DEGs' molecular processes and signal transduction pathways and observed that T2DM has certain connections to the progression of breast cancer. Using several computational and statistical approaches, we created a protein-protein interactions (PPI) network and revealed hub genes. These hub genes can be potential biomarkers, which may also lead to new therapeutic strategies for investigated diseases. We conducted TF-gene interactions, gene-microRNA interactions, protein-drug interactions, and gene-disease associations to find potential connections between T2DM and breast cancer pathologies. We assume that the potential drugs that emerged from this study could be useful therapeutic values. Researchers, doctors, biotechnologists, and many others may benefit from this research.

Systematic Review and Meta-Analysis of the Impact of Bariatric Surgery on Future Cancer Risk

The study aimed to perform a systematic review and meta-analysis of the evidence for the prevention of future cancers following bariatric surgery. A systematic literature search of the Cochrane Library, Embase, Scopus, Web of Science and PubMed databases (2007–2023), Google Scholar and grey literature was conducted. A meta-analysis was performed using the inverse variance method and random effects model. Thirty-two studies involving patients with obesity who received bariatric surgery and control patients who were managed with conventional treatment were included. The meta-analysis suggested bariatric surgery was associated with a reduced overall incidence of cancer (RR 0.62, 95% CI 0.46–0.84, p < 0.002), obesity-related cancer (RR 0.59, 95% CI 0.39–0.90, p = 0.01) and cancer-associated mortality (RR 0.51, 95% CI 0.42–0.62, p < 0.00001). In specific cancers, bariatric surgery was associated with reduction in the future incidence of hepatocellular carcinoma (RR 0.35, 95% CI 0.22–0.55, p < 0.00001), colorectal cancer (RR 0.63, CI 0.50–0.81, p = 0.0002), pancreatic cancer (RR 0.52, 95% CI 0.29–0.93, p = 0.03) and gallbladder cancer (RR 0.41, 95% CI 0.18–0.96, p = 0.04), as well as female specific cancers, including breast cancer (RR 0.56, 95% CI 0.44–0.71, p < 0.00001), endometrial cancer (RR 0.38, 95% CI 0.26–0.55, p < 0.00001) and ovarian cancer (RR 0.45, 95% CI 0.31–0.64, p < 0.0001). There was no significant reduction in the incidence of oesophageal, gastric, thyroid, kidney, prostate cancer or multiple myeloma after bariatric surgery as compared to patients with morbid obesity who did not have bariatric surgery. Obesity-associated carcinogenesis is closely related to metabolic syndrome; visceral adipose dysfunction; aromatase activity and detrimental cytokine, adipokine and exosomal miRNA release. Bariatric surgery results in long-term weight loss in morbidly obese patients and improves metabolic syndrome. Bariatric surgery may decrease future overall cancer incidence and mortality, including the incidence of seven obesity-related cancers.

Leptin signaling in breast cancer and its crosstalk with peroxisome proliferator-activated receptors α and γ

Obesity may create a mitogenic microenvironment that influences tumor initiation and progression. The obesity-associated adipokine, leptin regulates energy metabolism and has been implicated in cancer development. It has been shown that some cell types other than adipocytes can express leptin and leptin receptors in tumor microenvironments. It has been shown that peroxisome proliferator-activated receptors (PPAR) agonists can affect leptin levels and vice versa leptin can affect PPARs. Activation of PPARs affects the expression of several genes involved in aspects of lipid metabolism. In addition, PPARs regulate cancer cell progression through their action on the tumor cell proliferation, metabolism, and cellular environment. Some studies have shown an association between obesity and several types of cancer, including breast cancer. There is some evidence that suggests that there is crosstalk between PPARs and leptin during the development of breast cancer. Through a systematic review of previous studies, we have reviewed the published relevant articles regarding leptin signaling in breast cancer and its crosstalk with peroxisome proliferator-activated receptors α and γ.

Clinical trial-identified inflammatory biomarkers in breast and pancreatic cancers

Breast cancer and pancreatic cancer are two common cancer types characterized by high prevalence and high mortality rates, respectively. However, breast cancer has been more well-studied than pancreatic cancer. This narrative review curated inflammation-associated biomarkers from clinical studies that were systematically selected for both breast and pancreatic cancers and discusses some of the common and unique elements between the two endocrine-regulated malignant diseases. Finding common ground between the two cancer types and specifically analyzing breast cancer study results, we hoped to explore potential feasible methods and biomarkers that may be useful also in diagnosing and treating pancreatic cancer. A PubMed MEDLINE search was used to identify articles that were published between 2015-2022 of different kinds of clinical trials that measured immune-modulatory biomarkers and biomarker changes of inflammation defined in diagnosis and treatment of breast cancer and pancreatic cancer patients. A total of 105 papers (pancreatic cancer 23, breast cancer 82) were input into Covidence for the title and abstract screening. The final number of articles included in this review was 73 (pancreatic cancer 19, breast cancer 54). The results showed some of the frequently cited inflammatory biomarkers for breast and pancreatic cancers included IL-6, IL-8, CCL2, CD8+ T cells and VEGF. Regarding unique markers, CA15-3 and TNF-alpha were two of several breast cancer-specific, and CA19 and IL-18 were pancreatic cancer-specific. Moreover, we discussed leptin and MMPs as emerging biomarker targets with potential use for managing pancreatic cancer based on breast cancer studies in the future, based on inflammatory mechanisms. Overall, the similarity in how both types of cancers respond to or result in further disruptive inflammatory signaling, and that point to a list of markers that have been shown useful in diagnosis and/or treatment method response or efficacy in managing breast cancer could potentially provide insights into developing the same or more useful diagnostic and treatment measurement inflammatory biomarkers for pancreatic cancer. More research is needed to investigate the relationship and associated inflammatory markers between the similar immune-associated biological mechanisms that contribute to breast and pancreatic cancer etiology, drive disease progression or that impact treatment response and reflect survival outcomes.

Establishment of triple-negative breast cancer cells based on BMI: A novel model in the correlation between obesity and breast cancer

Introduction

Obesity has been associated with an increased risk of biologically aggressive variants in breast cancer. Women with obesity often have tumors diagnosed at later stages of the disease, associated with a poorer prognosis and a different response to treatment. Human cell lines have been derived from specific subtypes of breast cancer and have served to define the cell physiology of corresponding breast cancer subtypes. However, there are no current cell lines for breast cancer specifically derived from patients with different BMIs. The availability of those breast cancer cell lines should allow to describe and unravel functional alterations linked to these comorbidities.

Methods

Cell cultures were established from tumor explants. Once generated, the triple negative subtype in a patient with obesity and a patient with a normal BMI were chosen for comparison. For cellular characterization, the following assays were conducted: proliferation assays, chemo - sensitivity assays for doxorubicin and paclitaxel, wound healing motility assays, matrix invasion assays, breast cancer cell growth to estradiol by chronic exposure to leptin, induction of endothelial permeability and tumorigenic potential in athymic mice with normo - versus hypercaloric diets with an evaluation of the epithelium - mesenchymal transformation proteins.

Results

Two different cell lines, were established from patients with breast cancer: DSG-BC1, with a BMI of 21.9 kg/m2 and DSG-BC2, with a BMI of 31.5 kg/m2. In vitro, these two cell lines show differential growth rates, motility, chemosensitivity, vascular permeability, response to leptin with an activation of the JAK2/STAT3/AKT signaling pathway. In vivo, they displayed distinct tumorigenic potential. In particular, DSG-BC2, presented higher tumorigenicity when implanted in mice fed with a hypercaloric diet.

Discussion

To our knowledge, these primary cultures are the first in vitro representation of both breast cancer and obesity. DSG - BC2 presented a more aggressive in vivo and in vitro phenotype. These results support the hypothesis that breast cancer generated in an obese metabolic state may represent a contrasting variant within the same disease. This new model will allow both further comprehension, functional studies and the analysis of altered molecular mechanisms under the comorbidity of obesity and breast cancer.

RBCK1 regulates the progression of ER-positive breast cancer through the HIF1α signaling

Breast cancer is the most common malignancy in women on a global scale. It can generally be divided into four main categories, of which estrogen receptor ER-positive breast cancer accounts for most breast cancer cases. RBCK1 protein is an E3 ubiquitin ligase containing the UBL, NZF, and RBR domains. It is well known to exhibit abnormal expression in breast tumors, making it a valuable diagnostic marker and drug target. Additionally, studies have confirmed that in breast cancer, about 25 to 40% of tumors appear as visible hypoxic regions, while in hypoxia, tumor cells can activate the hypoxia-inducing factor HIF1 pathway and widely activate the expression of downstream genes. Previous studies have confirmed that in the hypoxic environment of tumors, HIF1α promotes the remodeling of extracellular matrix, induces the recruitment of tumor-associated macrophages (TAM) and immunosuppression of allogeneic tumors, thereby influencing tumor recurrence and metastasis. This research aims to identify RBCK1 as an important regulator of HIF1α signaling pathway. Targeted therapy with RBCK1 could be a promising treatment strategy for ER-positive breast cancer.

Obesity, inflammation, and cancer in dogs: Review and perspectives

Obesity is the most common nutritional disease in dogs, and its prevalence has increased in recent decades. Several countries have demonstrated a prevalence of obesity in dogs similar to that observed in humans. Chronic low-grade inflammation is a prominent basis used to explain how obesity results in numerous negative health consequences. This is well known and understood, and recent studies have pointed to the association between obesity and predisposition to specific types of cancers and their complications. Such elucidations are important because, like obesity, the prevalence of cancer in dogs has increased in recent decades, establishing cancer as a significant cause of death for these animals. In the same way, intensive advances in technology in the field of human and veterinary medicine (which even proposes the use of animal models) have optimized existing therapeutic methods, led to the development of innovative treatments, and shortened the time to diagnosis of cancer. Despite the great challenges, this review aims to highlight the evidence obtained to date on the association between obesity, inflammation, and cancer in dogs, and the possible pathophysiological mechanisms that link obesity and carcinogenesis. The potential to control cancer in animals using existing knowledge is also presented.

Epidemiology of Breast Cancer in Mexican Women with Obesity as a Risk Factor

Purpose. Adipose tissue in overweight and obesity shows metabolic imbalance in the function of adipocytes and macrophages, this leads to altered regulation of hunger, lipid storage, and chronic inflammation possibly related to the development of breast cancer. Methods. The study was retrospective of 653 breast cancer patients treated at a tertiary care hospital. Histopathology, hormone receptors, grade, clinical stage, clinical biometry analysis, CEA and CA 15-3 antigens were analyzed. The analyses were performed at diagnosis and at the end of oncological treatments. Results. Mexican women studied and treated for breast cancer have an BMI of 29 from diagnosis and at the end of their cancer treatments. The average age was 52 ± 12 years, 54% in women older than 55 years. Cancer recurrence occurs in any molecular type; however, the common factor was overweight and obesity with 73% vs. 21% in normal weight patients. The most frequent tumor tissue in the population was positive hormone receptors of the luminal type (65%), HER2 (15%), and NT (15%). The analyses of macrophages/lymphocytes (M/L), CEA, and CA 15-3 antigens evaluated in women >55 and <55 years, with and without recurrence are elevated at the end of oncological treatments. Conclusions. The analysis of Mexican women with breast cancer showed a predominance of overweight and obesity at diagnosis and at the end of treatment. A relationship between obesity and cancer recurrence with a low response to treatment due to elevation in Ag CEA and CA 15-3 is suggested. The L/M ratio could be an indicator of inflammation related to adipose tissue since diagnosis.

The role of obesity and bariatric surgery-induced weight loss in breast cancer

Obesity is a complex metabolic condition considered a worldwide public health crisis, and a deeper mechanistic understanding of obesity-associated diseases is urgently needed. Obesity comorbidities include many associated cancers and are estimated to account for 20% of female cancer deaths in the USA. Breast cancer, in particular, is associated with obesity and is the focus of this review. The exact causal links between obesity and breast cancer remain unclear. Still, interactions have emerged between body mass index, tumor molecular subtype, genetic background, and environmental factors that strongly suggest obesity influences the risk and progression of certain breast cancers. Supportive preclinical research uses various diet-induced obesity models to demonstrate that weight loss, via dietary interventions or changes in energy expenditure, reduces the onset or progression of breast cancers. Ongoing and future studies are now aimed at elucidating the underpinning mechanisms behind weight-loss-driven observations to improve therapy and outcomes in patients with breast cancer and reduce risk. This review aims to summarize the rapidly emerging literature on obesity and weight loss strategies with a focused discussion of bariatric surgery in both clinical and preclinical studies detailing the complex interactions between metabolism, immune response, and immunotherapy in the setting of obesity and breast cancer.

Altered Adipokine Expression in Tumor Microenvironment Promotes Development of Triple Negative Breast Cancer

Obesity is a remarkably important factor for breast carcinogenesis and aggressiveness. The implication of increased BMI in triple negative breast cancer (TNBC) development is also well established. A malignancy-promoting role of the adipose tissue has been supposed, where the adipocytes that constitute the majority of stromal cells release pro-inflammatory cytokines and growth factors. Alterations in adipokines and their receptors play significant roles in breast cancer initiation, progression, metastasis, and drug response. Classic adipokines, such as leptin, adiponectin, and resistin, have been extensively studied in breast cancer and connected with breast cancer risk and progression. Notably, new molecules are constantly being discovered and the list is continuously growing. Additionally, substantial progress has been made concerning their differential expression in association with clinical and pathological parameters of tumors and the prognostic and predictive value of their dysregulation in breast cancer carcinogenesis. However, evidence regarding the mechanisms by which adipose tissue is involved in the development of TNBC is lacking. In the present article we comment on current data on the suggested involvement of these mediators in breast cancer development and progression, with particular emphasis on TNBC, to draw attention to the design of novel targeted therapies and biomarkers.

The Emerging Role of Cyclin-Dependent Kinase Inhibitors in Treating Diet-Induced Obesity: New Opportunities for Breast and Ovarian Cancers?

Overweight and obesity constitute the most impactful lifestyle-dependent risk factors for cancer and have been tightly linked to a higher number of tumor-related deaths nowadays. The excessive accumulation of energy can lead to an imbalance in the level of essential cellular biomolecules that may result in inflammation and cell-cycle dysregulation. Nutritional strategies and phytochemicals are gaining interest in the management of obesity-related cancers, with several ongoing and completed clinical studies that support their effectiveness. At the same time, cyclin-dependent kinases (CDKs) are becoming an important target in breast and ovarian cancer treatment, with various FDA-approved CDK4/6 inhibitors that have recently received more attention for their potential role in diet-induced obesity (DIO). Here we provide an overview of the most recent studies involving nutraceuticals and other dietary strategies affecting cell-cycle pathways, which might impact the management of breast and ovarian cancers, as well as the repurposing of already commercialized chemotherapeutic options to treat DIO.

Single-Nucleotide Polymorphisms in LEP and LEPR Associated With Breast Cancer Risk: Results From a Multicenter Case-Control Study in Chinese Females

Background

Leptin (LEP) plays a physiological role through its specific receptor (LEPR) and is involved in the occurrence and development of breast cancer. Our current study aimed at determining the influence of single-nucleotide polymorphisms (SNPs) in the genes coding for LEP and LEPR on breast cancer risk.

Methods

In the present study, 963 breast cancer cases and 953 controls were enrolled. Five SNPs of LEP and two of LEPR were chosen to evaluate the correlation of selected SNPs with breast cancer susceptibility among women in northern and eastern China. Analyses were further stratified by body mass index (BMI), waist–hip rate (WHR), estrogen receptor, and progesterone receptor status. The expression patterns of risk variant-associated genes were detected by expression quantitative trait locus (eQTL) analysis with eQTLGen and The Cancer Genome Atlas database.

Results

There were significant differences between breast cancer cases and control groups in the menopausal status and family history of breast cancer. Two SNPs (rs1137101 and rs4655555) of the LEPR gene decreased overall breast cancer risk, and other five SNPs showed no significant association with breast cancer risk. rs1137101 (GA vs. GG; adjusted OR = 0.719, 95% CI = 0.578–0.894, p = 0.003) and rs4655555 (TT vs. AA; adjusted OR = 0.574, 95% CI = 0.377–0.873, p = 0.009) significantly decreased breast cancer risk after Bonferroni correction for multiple testing. In subgroup analyses, the GA and GA + AA genotypes of LEPR rs1137101 associated with decreased breast cancer risk in the subgroup of BMI ≤ 24 kg/m² or WHR ≥ 0.85 after Bonferroni correction. Furthermore, we found that the expressions of rs4655555-associated gene LEPR and leptin receptor overlapping transcript (LEPROT) were upregulated in breast cancer tumor tissues compared with adjacent normal tissues, and a higher expression of LEPR in tumor tissues was correlated with poor prognosis of breast cancer patients using The Cancer Genome Atlas Breast Invasive Carcinoma (TCGA-BRCA) data.

Conclusion

Our study demonstrated that the polymorphisms rs1137101 and rs4655555 located in the LEPR gene decreased breast cancer risk in Chinese females, which might be a research-worthy bio-diagnostic marker and applied for early prediction and risk assessment of breast cancer.

Leptin Enhances Hepatic Fibrosis and Inflammation in a Mouse Model of Cholestasis

Leptin is an adipokine with roles in food intake and energy metabolism through its actions on neurons in the hypothalamus. The role of leptin in obesity and cardiovascular disorders is well documented. However, its influence on liver conditions such as cholestasis is poorly understood. The effects of exogenous leptin and leptin-neutralizing antibody on biliary hyperplasia, hepatic fibrosis, and inflammation in the multidrug resistance protein 2 knockout (Mdr2KO) mouse model of cholestasis were assessed by quantifying markers specific for cholangiocytes, activated hepatic stellate cells (HSCs), and cytokines. Serum and hepatic leptin were increased in Mdr2KO mice compared with FVB/NJ (FVBN) controls, and exogenous leptin enhanced biliary hyperplasia and liver fibrosis in Mdr2KO and FVBN mice. Leptin administration increased hepatic expression of C-C motif chemokine ligand 2 and IL-6 in Mdr2KO mice. In contrast, leptin-neutralizing antibody reduced intrahepatic bile duct mass and decreased HSC activation in Mdr2KO mice compared with FVBN controls. Sex-related differences were noted, with female Mdr2KO mice having more leptin than males. In cholangiocytes and LX2 cells in vitro, leptin increased phosphorylated Akt and stimulated cell proliferation. Leptin receptor siRNA and inhibitors of Akt phosphorylation impaired leptin-induced cell proliferation and proinflammatory cytokines. The current data suggest that leptin is abnormally increased in cholestatic mice, and excess leptin increases ductular reaction, hepatic fibrosis, and inflammation via leptin receptor-mediated phosphorylation of Akt in cholangiocytes and HSCs.

Celastrol inhibits the proliferation and migration of MCF-7 cells through the leptin-triggered PI3K/AKT pathway

Leptin is the pivotal modulator in the onset and progression of breast cancer and obesity. Celastrol, which is extracted from the roots of Tripterygium wilfordi plants, exerts various anticancer bioactivities and has recently emerged as a candidate to treat obesity by improving leptin sensitivity. However, the relationship between leptin and celastrol in the treatment of breast cancer is unknown. Here, the growth and migration of MCF-7 cells induced by leptin were tested to demonstrate the antineoplastic activity of celastrol. Transcriptomic analysis and western blotting were conducted to explore the biological roles of leptin in treating breast cancer with celastrol. The present findings showed that celastrol remarkably reversed leptin-triggered cell proliferation and migration in MCF-7 cells. Fifty-two mRNAs with fivefold higher counts and 149 mRNAs with fivefold lower counts were identified in the celastrol-treated MCF-7 cells. According to the GO and KEGG analyses, the effects of celastrol on MCF-7 cells forced lipid metabolism and the endocrine system. Moreover, leptin treatment induced phosphorylation of leptin receptor and PI3K/AKT in MCF-7 cells, whereas pretreatment with celastrol partly abrogated leptin activation. The binding of celastrol to the leptin receptor was also confirmed by molecular docking. The antitumor effect of celastrol is proposed to be mediated by its binding to the leptin receptor and controlled downregulation of the PI3K/AKT pathway.

Association of Leptin Receptor Q223R Gene Polymorphism and Breast Cancer Patients: A Case Control Study

INTRODUCTION

Leptin is a hormone secreted from adipocytes that regulates metabolism and energy homeostasis through the leptin receptor (LEPR). The aim of this study was to investigate the association of leptin receptor gene Q223R gene polymorphism, and plasma leptin level among obese breast cancer females.

MATERIALS AND METHODS

The study enrolled 160 breast cancer patients and 160 healthy control females. LEPR Q223R polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum leptin was determined using enzyme-linked immunosorbent assay human leptin kit.  Immunohistochemical tests from paraffin blocks were carried out for estrogen and progesterone staging using the precise antibodies.

RESULTS

An association was found between LEPR gene Q223R gene polymorphism among obese breast cancer females. Statistical difference was found between GG (60.6%) Arg/Arg genotype (OR=2.986; 95%CI=1.540 to 5.789; p= 0.001) compared to AA (33.1%) Gln/Gln genotype. GG Q223R LEPR polymorphism showed statistically significant difference among obese breast cancer patients (BMI more than 25) compared to control (P < 0.0001). GG genotype of Q223R LEPR polymorphism showed statistically significant increased leptin level (p-value =0.0001) among obese patients (mean± SD; 23.39±4.32) compared to control (17.83±5.67).

CONCLUSIONS

Q223R LEPR polymorphism GG genotype was associated with increased leptin profile among obese breast cancer females.

Personalized Nutrition as a Key Contributor to Improving Radiation Response in Breast Cancer

Understanding metabolic and immune regulation inherent to patient populations is key to improving the radiation response for our patients. To date, radiation therapy regimens are prescribed based on tumor type and stage. Patient populations who are noted to have a poor response to radiation such as those of African American descent, those who have obesity or metabolic syndrome, or senior adult oncology patients, should be considered for concurrent therapies with radiation that will improve response. Here, we explore these populations of breast cancer patients, who frequently display radiation resistance and increased mortality rates, and identify the molecular underpinnings that are, in part, responsible for the radiation response and that result in an immune-suppressive tumor microenvironment. The resulting immune phenotype is discussed to understand how antitumor immunity could be improved. Correcting nutrient deficiencies observed in these populations should be considered as a means to improve the therapeutic index of radiation therapy.

Leptin as a Biomarker of Stress: A Systematic Review and Meta-Analysis

BACKGROUND

Leptin is a satiety hormone mainly produced by white adipose tissue. Decreasing levels have been described following acute stress.

OBJECTIVE

To conduct a systematic review and meta-analysis to determine if leptin can be a biomarker of stress, with levels decreasing following acute stress.

METHODS

PubMed, Cochrane Library, Embase, and ScienceDirect were searched to obtain all articles studying leptin levels after acute stress on 15 February 2021. We included articles reporting leptin levels before and after acute stress (physical or psychological) and conducted random effects meta-analysis (DerSimonian and Laird approach). We conducted Meta-regressions and sensitivity analyses after exclusion of groups outside the metafunnel.

RESULTS

We included seven articles-four cohort and three case-control studies-(28 groups) from 27,983 putative articles. Leptin levels decreased after the stress intervention (effect size = -0.34, 95%CI -0.66 to -0.02) compared with baseline levels, with a greater decrease after 60 min compared to mean decrease (-0.45, -0.89 to -0.01) and in normal weight compared to overweight individuals (-0.79, -1.38 to -0.21). There was no difference in the overweight population. Sensitivity analyses demonstrated similar results. Levels of leptin after stress decreased with sex ratio-i.e., number of men/women-(-0.924, 95%CI -1.58 to -0.27) and increased with the baseline levels of leptin (0.039, 0.01 to 0.07).

CONCLUSIONS

Leptin is a biomarker of stress, with a decrease following acute stress. Normal-weight individuals and women also have a higher variation of leptin levels after stress, suggesting that leptin may have implications in obesity development in response to stress in a sex-dependent manner.

Metabolic Hormones Modulate Macrophage Inflammatory Responses

Simple Summary

Macrophages are a type of immune cell which play an important role in the development of cancer. Obesity increases the risk of cancer and obesity also causes disruption to the normal levels of hormones that are produced to coordinate metabolism. Recent research now shows that these metabolic hormones also play important roles in macrophage immune responses and so through macrophages, disrupted metabolic hormone levels may promote cancer. This review article aims to highlight and summarise these recent findings so that the scientific community may better understand how important this new area of research is, and how these findings can be capitalised on for future scientific studies.

Abstract

Macrophages are phagocytotic leukocytes that play an important role in the innate immune response and have established roles in metabolic diseases and cancer progression. Increased adiposity in obese individuals leads to dysregulation of many hormones including those whose functions are to coordinate metabolism. Recent evidence suggests additional roles of these metabolic hormones in modulating macrophage inflammatory responses. In this review, we highlight key metabolic hormones and summarise their influence on the inflammatory response of macrophages and consider how, in turn, these hormones may influence the development of different cancer types through the modulation of macrophage functions.

Targeting Adipokines in Obesity-Related Tumors

Obesity, a global epidemic, is an independent risk factor for the occurrence and development of a variety of tumors, such as breast cancer, pancreatic cancer, ovarian cancer and colorectal cancer. Adipocytes are important endocrine cells in the tumor microenvironment of obesity-related tumors, which can secrete a variety of adipokines (such as leptin, adiponectin, estrogen, resistin, MIF and MCP-1, etc.), among which leptin, adiponectin and estrogen are the most in-depth and valuable ones. These adipokines are closely related to tumorigenesis and the progression of tumors. In recent years, more and more studies have shown that under chronic inflammatory conditions such as obesity, adipocytes secrete more adipokines to promote the tumorigenesis and development of tumors. However, it is worth noting that although adiponectin is also secreted by adipocytes, it has an anti-tumor effect, and can cross-talk with other adipokines (such as leptin and estrogen) and insulin to play an anti-tumor effect together. In addition, obesity is the main cause of insulin resistance, which can lead to the increase of the expression levels of insulin and insulin-like growth factor (IGF). As important regulators of blood glucose and lipid metabolism, insulin and IGF also play an important role in the progress of obesity related tumors. In view of the important role of adipokines secreted by adipocytes and insulin/IGF in tumors, this article not only elaborates leptin, adiponectin and estrogen secreted by adipocytes and their mechanism of action in the development of obesity- related tumors, but also introduces the relationship between insulin/IGF, a regulator of lipid metabolism, and obesity related tumors. At the same time, it briefly describes the cancer-promoting mechanism of resistin, MIF and MCP-1 in obesity-related tumors, and finally summarizes the specific treatment opinions and measures for various adipokines and insulin/insulin-like growth factors in recent years.

The Effects of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Inflammatory Markers, Body Composition, and Physical Fitness in Overweight/Obese Survivors of Breast Cancer: A Randomized Controlled Clinical Trial

Background: Chronic inflammation associated with breast cancer (BC) poses a major challenge in care management and may be ameliorated by physical activity. This randomized controlled trial assessed the effects of a 12-week high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on inflammatory markers, body composition, and physical fitness in BC survivors (BCS). Methods: Forty BCS (age = 57 ± 1 years; body mass [BM] = 74.8 ± 1.5 kg; VO2peak = 20.8 ± 2.1 mL·kg-1·min-1) were randomly assigned to three groups: HIIT (n = 15), MICT (n = 15), or control (CON; n = 15). The intervention groups (HIIT and MICT) performed their respective exercise protocols on a cycle ergometer 3 days/week for 12 weeks while the CON group maintained their current lifestyle. Baseline and post-intervention assessments included body composition (BM, fat mass (FM), lean mass (LM)), physical fitness (VO2peak, lower body strength (LBS), upper body strength (UBS)), and serum concentrations of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), leptin, and adiponectin. Results: Both intervention groups significantly (p < 0.05) decreased BM (HIIT = -1.8 kg, MICT = -0.91 kg), FM (HIIT = -0.81 kg, MICT = -0.18 kg), TNF-α (HIIT = -1.84 pg/mL, MICT = -0.99 pg/mL), IL-6 (HIIT = -0.71 pg/mL, MICT = -0.36 pg/mL), leptin (HIIT = -0.35 pg/mL, MICT = -0.16 pg/mL) and increased VO2peak (HIIT = 0.95 mL·kg-1·min-1, MICT = 0.67 mL·kg-1·min-1), LBS (HIIT = 2.84 kg, MICT = 1.53 kg), UBS (HIIT = 0.53 kg, MICT = 0.53 kg), IL-10 (HIIT = 0.63 pg/mL, MICT = 0.38 pg/mL), and adiponectin (HIIT = 0.23 ng/mL, MICT = 0.1 ng/mL) compared to baseline. The changes in BM, FM, TNF-α, leptin, and LBS were significantly greater in HIIT compared to all other groups. Conclusions: Our findings indicate that compared to the often-recommended MICT, HIIT may be a more beneficial exercise therapy for the improvement of inflammation, body composition and LBS in BCS; and consequently, merits long-term study.

Triazine Derivative as Putative Candidate for the Reduction of Hormone-Positive Breast Tumor: In Silico, Pharmacological, and Toxicological Approach

Background and objectives: Breast cancer is a heterogeneous disease that poses the highest incidence of morbidity among women and presents many treatment challenges. In search of novel breast cancer therapies, several triazine derivatives have been developed for their potential chemotherapeutic activity. This study aims to evaluate the N-nitroso-N-methyl urea (NMU)-induced anti-mammary gland tumor activity of 2,4,6 (O-nitrophenyl amino) 1,3,5-triazine (O-NPAT). Methods: The in silico modeling and in vitro cytotoxicity assay were performed to strengthen the research hypothesis. For in vivo experimentation, 30 female rats were divided into five groups. Group I (normal control) received normal saline. Group II (disease control) received NMU (50 mg/kg). Group III (standard control) was treated with tamoxifen (5 mg/kg). Groups IV and V received O-NPAT at a dose level of 30 and 60 mg/kg, respectively. For tumor induction, 3 intraperitoneal doses of NMU were given at a 3-week interval, whereas all treatment compounds were administered orally for 14 consecutive days. Biochemical and oxidative stress markers were estimated for all experimental animals. DNA strand breakage alongside inflammatory markers was also measured for the analysis of inflammation. The hormonal profile of progesterone and estrogen was also estimated. Results: The test compound presented a significant reduction in organ weight and restored the hepatic and renal enzymes. O-NPAT treatments enhanced the antioxidant enzyme level of catalase (CAT), superoxide dismutase (SOD), and total sulfhydryl (TSH), with a highly significant reduction in lactate dehydrogenase (LDH) and lipid peroxidation. Also, the decrease in fragmented DNA, hormonal levels (estradiol and progesterone), and inflammatory cytokines (IL-6 and TNF-α) justified the dosage efficacy further supported by histopathological findings. Conclusion: All results indicated the anti-breast tumor activity of O-NPAT and presented its possibility of exploitation for beneficial effects in breast cancer treatment.

Hypoxia in Breast Cancer-Scientific Translation to Therapeutic and Diagnostic Clinical Applications

Breast cancer has been the leading cause of female cancer deaths for decades. Intratumoral hypoxia, mainly caused by structural and functional abnormalities in microvasculature, is often associated with a more aggressive phenotype, increased risk of metastasis and resistance to anti-malignancy treatments. The response of cancer cells to hypoxia is ascribed to hypoxia-inducible factors (HIFs) that activate the transcription of a large battery of genes encoding proteins promoting primary tumor vascularization and growth, stromal cell recruitment, extracellular matrix remodeling, cell motility, local tissue invasion, metastasis, and maintenance of the cancer stem cell properties. In this review, we summarized the role of hypoxia specifically in breast cancer, discuss the prognostic and predictive value of hypoxia factors, potential links of hypoxia and endocrine resistance, cancer hypoxia measurements, further involved mechanisms, clinical application of hypoxia-related treatments and open questions.

Molecular insights into the interplay between adiposity, breast cancer and bone metastasis

Cancer is a complex disease, with various pre-existing health ailments enhancing its pathology. In cancer, the extracellular environment contains various intrinsic physiological factors whose levels are altered with aging and pre-existing conditions. In obesity, the tumor microenvironment and metastases are enriched with factors that are both derived locally, and from other physiological compartments. Similarly, in obesity, the cancer cell environment both at the site of origin and at the secondary site i.e., metastatic niche, contains significantly more phenotypically-altered adipocytes than that of un-obese cancer patients. Indeed, obesity has been linked with cancer progression, metastasis, and therapy resistance. Adipocytes not only interact with tumor cells, but also with adjacent stromal cells at primary and metastatic sites. This review emphasizes the importance of bidirectional interactions between adipocytes and breast tumor cells in breast cancer progression and its bone metastases. This paper not only chronicles the role of various adipocyte-derived factors in tumor growth, but also describes the significance of adipocyte-derived bone metastatic factors in the development of bone metastasis of breast cancer. It provides a molecular view of the interplay between the adipocytes and tumor cells involved in breast cancer bone metastasis. However, more research is needed to determine if targeting cancer-associated adipocytes holds promise as a potential therapeutic approach for breast cancer bone metastasis treatment. Interplay between adipocytes and breast cancer cells at primary cancer site and metastatic bone microenvironment. AMSC Adipose-derived mesenchymal stem cell, CAA Cancer associated adipocytes, CAF Cancer associated fibroblast, BMSC Bone marrow derived mesenchymal stem cell, BMA Bone marrow adipocyte.

Combination of Endogenous Estradiol and Adipokine Leptin in Breast Cancer Risk and Prognosis Assessment in Postmenopausal Chinese Women

OBJECTIVE

Our study aims to clarify the role of estradiol and leptin in breast cancer risk and prognostic assessment in postmenopausal Chinese women.

DESIGN

The serum circulating estradiol and leptin level was detected by ELISA. Then the correlation between estradiol, leptin level, and clinical characteristics was analyzed using Fisher's exact test. Next, the Kaplan-Meier model was used to analyze the association between estradiol, leptin, and prognosis of postmenopausal breast cancer patients in our cohort and the TCGA dataset.

SETTING

The study was conducted at the National Cancer Center, Cancer Hospital, Chinese Academy of Medical Sciences, and Peking Union Medical College.

PATIENTS

A total of 182 postmenopausal breast cancer patients and 111 healthy subjects from January 2010 to August 2010 were included in the analysis. Another 702 cases with breast cancer were retrieved from The Cancer Genome Atlas (TCGA) database for subsequent analysis.

MAIN OUTCOME MEASURE

Serum circulating estradiol and leptin level.

RESULTS

The level of estradiol was significantly higher (P<0.001) but the level of leptin had no significant difference (P = 0.764) in postmenopausal breast cancer patients compared with healthy subjects. The level of estradiol and leptin was not significantly different between estrogen receptor (ER) positive and ER-negative groups (P>0.05). Estradiol was significantly correlated with tumor T stage (P = 0.002) and leptin was significantly associated with perineural invasion (P = 0.014). In addition, the disease-free survival of patients with a high level of estradiol was significantly shorter (P = 0.025) but leptin tended to be a protective factor for overall survival in TCGA analysis (P = 0.038).

CONCLUSION

Circulating estradiol and leptin played important roles in the risk of postmenopausal breast cancer even in low-estrogen nations with an independent expression of ER status. High circulating estradiol was a poor prognostic factor and leptin may be a protection signal in Chinese postmenopausal patients with breast cancer.

Obesity Epidemic-The Underestimated Risk of Endometrial Cancer

Endometrial cancer (EC) is the most frequently observed malignant gynecologic disease in developed countries. There is a strong association between the established risk factor obesity and the incidence of EC. Furthermore, the rate of women with a body mass index (BMI) > 30 kg/m2 is increasing worldwide, correspondingly leading to a higher prevalence of EC. Understanding the adipose tissue as an endocrine organ, elementary pathophysiological pathways of tumorigenesis have been revealed. This includes the fundamental role of hyperglycemia, insulin resistance, and hyperestrogenemia, as well as interactions with a chronic proinflammatory microenvironment. Therapeutic options potentially include metformin or bariatric surgery. Moreover, changes in individual lifestyle such as weight reduction, physical activity, and an awareness of healthy nutrition are effective in preventing the disease.

Endurance Exercise Mitigates Immunometabolic Adipose Tissue Disturbances in Cancer and Obesity

Adipose tissue is considered an endocrine organ whose complex biology can be explained by the diversity of cell types that compose this tissue. The immune cells found in the stromal portion of adipose tissue play an important role on the modulation of inflammation by adipocytokines secretion. The interactions between metabolic active tissues and immune cells, called immunometabolism, is an important field for discovering new pathways and approaches to treat immunometabolic diseases, such as obesity and cancer. Moreover, physical exercise is widely known as a tool for prevention and adjuvant treatment on metabolic diseases. More specifically, aerobic exercise training is able to increase the energy expenditure, reduce the nutrition overload and modify the profile of adipocytokines and myokines with paracrine and endocrine effects. Therefore, our aim in this review was to cover the effects of aerobic exercise training on the immunometabolism of adipose tissue in obesity and cancer, focusing on the exercise-related modification on adipose tissue or immune cells isolated as well as their interaction.

Association Between Serum Insulin and C-Peptide Levels and Breast Cancer: An Updated Systematic Review and Meta-Analysis

Background

Several studies have reported that hyperinsulinemia plays a part in the etiology of breast cancer. However, no consensus has been reached. Therefore, we conducted a meta-analysis to explore the role of insulin and C-peptide in breast cancer.

Methods

A systematic search in PubMed, Embase, and The Cochrane Library was conducted up to September, 2020. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were used to measure effect sizes. Publication bias was assessed using the Egger test. Stability of these results was evaluated using sensitivity analyses.

Results

Fourteen articles including 27,084 cases and five articles including 2,513 cases were extracted for serum insulin levels and C-peptide levels. We found that C-peptide levels were positively associated with breast cancer with overall SMD = 0.37 (95% CI = 0.09–0.65, I² = 89.1%). Subgroup analysis by control source illustrated a positive relationship between breast cancer and C-peptide levels in population-based control. Subgroup analysis by C-peptide level indicated a positive correlation between breast cancer and C-peptide levels no matter C-peptide levels in case group is ≤3 ng/ml or >3 ng/ml. Subgroup analysis by age showed that C-peptide level positively correlated to breast cancer in women between the ages of 50 and 60. However, we did not identify any relationship between breast cancer and insulin levels (SMD = 0.22, 95% CI = −0.06–0.50, I² = 97.3%).

Conclusion

This meta-analysis demonstrated that C-peptide levels were positively related to breast cancer in women, and no relationship between insulin levels and breast cancer was found.

Identification of Aurora Kinase A as a Biomarker for Prognosis in Obesity Patients with Early Breast Cancer

BACKGROUND

Obesity is associated both with a higher risk of developing breast cancer, particularly in postmenopausal women, and with worse disease outcome for women of all ages. Previous investigation suggested Aurora A kinase was able to partially restore the functionalities of obese adipose-derived mesenchymal stem cells by stabilizing their primary cilia and reestablishing a balance of multiple stemness-associated genes. The association between Aurora A and obesity breast cancer is still unclear. We hypothesized that overexpression of Aurora A was associated with poor survival in obesity breast cancer and the related axis mechanism was involved.

METHODS

A total of 517 primary breast cancer specimens were collected from the First Affiliated Hospital of China Medical University between January 2011 and November 2016. Our independent variable was BMI at baseline, categorized as overweight (BMI ≥25 kg/m2, as obesity cohort), and normal (18.5 ≤ BMI <25 kg/m2, as non-obesity cohort). The immunohistochemical (IHC) staining was performed with Aurora A, Survivin, MMP11, Cyclin B1, and Cathepsin L. Kaplan-Meier curve was used to analyze overall survival in our cohorts and TCGA-BRCA data (GSE3494). Log rank test was used to calculate P values. Protein-protein interaction (PPI) network analysis and MCODE model were used to analyze the Aurora-altered signal pathway from GSE78958.

RESULTS

Among 517 breast patients, Aurora A-positive (staining scores ≥4) was significantly higher in obesity breast carcinoma compared with non-obesity cancer carcinoma (χ 2=9.79, P=0.002), with more frequency in hormone receptor-negative (68.4% vs 77.9%, P=0.015) and HER2-positive patients (28.7% vs 17.9%, P=0.003). High Aurora A expression was remarkably and significantly associated with overall survival (OS) (8-year OS ratio: 69.5% vs 81.1%, OR=1.76, 95% CI: 1.03~3.02, P=0.041) in obesity cohort. Interestingly, higher expression of Aurora A was not associated with a shorter overall survival time among the non-obesity breast cancer (8-year OS ratio: 81.4% vs 85.8%, OR=1.40, 95% CI: 0.79~2.45, P=0.229). As for RFS, the expression levels of Aurora A expression genes have no significance with RFS statistically in non-obesity and obesity patients. Aurora A and lymph node metastases were significantly poor prognostic factors for OS, and borderline significance was noted for high BMI. Kaplan-Meier survival analysis from TCGA database confirmed that the high Aurora A expression group had worse prognosis (HR=1.47, 95% CI: 1.14-1.90, P=0.003). The KEGG pathway enrichment results were consistent with GO biological process term analysis, in which CCNB1 was enriched for upregulated Aurora A. In our samples, Aurora A level on tumor cytoplasm had broad connections with Cyclin B1 by IHC correlation analysis (correlation coefficient = 0.227, P=0.001).

CONCLUSION

Our finding demonstrates here for the first time that high expression of Aurora A was notably correlated with early recurrence and poor overall survival in obesity patients with early breast cancer. The Aurora A-Cyclin B1 axis could be a potential promising therapeutic target for cancer intervention and therapy.

Metabolic Heterogeneity of Cancer Cells: An Interplay between HIF-1, GLUTs, and AMPK

It has been long recognized that cancer cells reprogram their metabolism under hypoxia conditions due to a shift from oxidative phosphorylation (OXPHOS) to glycolysis in order to meet elevated requirements in energy and nutrients for proliferation, migration, and survival. However, data accumulated over recent years has increasingly provided evidence that cancer cells can revert from glycolysis to OXPHOS and maintain both reprogrammed and oxidative metabolism, even in the same tumor. This phenomenon, denoted as cancer cell metabolic plasticity or hybrid metabolism, depends on a tumor micro-environment that is highly heterogeneous and influenced by an intensity of vasculature and blood flow, oxygen concentration, and nutrient and energy supply, and requires regulatory interplay between multiple oncogenes, transcription factors, growth factors, and reactive oxygen species (ROS), among others. Hypoxia-inducible factor-1 (HIF-1) and AMP-activated protein kinase (AMPK) represent key modulators of a switch between reprogrammed and oxidative metabolism. The present review focuses on cross-talks between HIF-1, glucose transporters (GLUTs), and AMPK with other regulatory proteins including oncogenes such as c-Myc, p53, and KRAS; growth factor-initiated protein kinase B (PKB)/Akt, phosphatydyl-3-kinase (PI3K), and mTOR signaling pathways; and tumor suppressors such as liver kinase B1 (LKB1) and TSC1 in controlling cancer cell metabolism. The multiple switches between metabolic pathways can underlie chemo-resistance to conventional anti-cancer therapy and should be taken into account in choosing molecular targets to discover novel anti-cancer drugs.

Diallyl Trisulfide Inhibits Leptin-induced Oncogenic Signaling in Human Breast Cancer Cells but Fails to Prevent Chemically-induced Luminal-type Cancer in Rats

Previous studies have demonstrated inhibitory effect of garlic component diallyl trisulfide (DATS) on growth of breast cancer cells in vitro and in vivo. This study investigated the effect of DATS on oncogenic signaling regulated by leptin, which plays an important role in breast carcinogenesis. Leptin-induced phosphorylation and nuclear translocation of STAT3 was inhibited significantly in the presence of DATS in MCF-7 (a luminal-type human breast cancer cell line) and MDA-MB-231 (a basal-like human breast cancer cell line). Leptin-stimulated cell proliferation, clonogenic cell survival, and migration and/or invasion ability in MCF-7 and/or MDA-MB-231 cells were also suppressed by DATS treatment. DATS exposure resulted in inhibition of leptin-stimulated expression of protein and/or mRNA levels of Bcl-2, Bcl-xL, Cyclin D1, vascular endothelial growth factor, and matrix metalloproteinase-2. Western blotting revealed a decrease in protein levels of phosphorylated STAT3 in breast cancer xenografts from DATS-treated mice when compared to controls in vivo. However, the incidence of N-methyl-N-nitrosourea-induced luminal-type breast cancer development in rats was not affected by oral administration of 5 mg/kg or 25 mg/kg DATS. The present study reveals that oncogenic signaling induced by leptin is inhibited in the presence of DATS but higher doses of this phytochemical may be required to achieve chemopreventive activity.