Obesity, Leptin and Breast Cancer: Epidemiological Evidence and Proposed Mechanisms

The interrelationship between obesity and race in breast cancer prognosis: a prospective cohort study

BACKGROUND

Obesity is associated with an increased breast cancer risk in postmenopausal women and may contribute to worse outcomes. Black women experience higher obesity and breast cancer mortality rates than non-Black women. We examined associations between race, obesity, and clinical tumor stage with breast cancer prognosis.

METHODS

We conducted a prospective cohort study in 1,110 breast cancer patients, using univariable and multivariable Cox regression analyses to evaluate the effects of obesity, race/ethnicity, and clinical tumor stage on progression-free and overall survival (PFS and OS).

RESULTS

22% of participants were Black, 64% were Hispanic White, and 14% were non-Hispanic White or another race. 39% of participants were obese (body mass index [BMI] ≥ 30 kg/m2). In univariable analyses, tumor stage III-IV was associated with worse PFS and OS compared to tumor stage 0-II (hazard ratio [HR] = 4.68, 95% confidence interval [CI] = 3.52-6.22 for PFS and HR = 5.92, 95% CI = 4.00-8.77 for OS). Multivariable analysis revealed an association between Black race and worse PFS in obese (HR = 2.19, 95% CI = 1.06-4.51) and non-obese (HR = 2.11, 95% CI = 1.05-4.21) women with tumors staged 0-II. Obesity alone was not associated with worse PFS or OS.

CONCLUSIONS

Results suggest a complex interrelationship between obesity and race in breast cancer prognosis. The association between the Black race and worse PFS in tumor stages 0-II underscores the importance of early intervention in this group. Future studies are warranted to evaluate whether alternative measures of body composition and biomarkers are better prognostic indicators than BMI among Black breast cancer survivors.

Body mass index and altered lipid profile as major risk markers for breast cancer progression: a cross-sectional study of postmenopausal women in Pakistan

BACKGROUND

In Pakistan, the death rate for post-menopausal women with breast cancer is significant due to late detection and delayed referral to proper facilities. There are a few reports on Pakistan's epidemiology and breast cancer risk factors. There are modifiable and non-modifiable risk factors associated with the development of breast carcinoma; of which body mass index (BMI), central obesity, and lipid profile are considered as major risk markers.

METHODS

This was a cross-sectional analytical study. A total of 384 women constituted the present study sample. Purposive sampling was used to collect 192 confirmed new breast cancer cases throughout the study. By using basic random sampling, an equal number of controls were chosen. Studied parameters included age, fasting blood sugar, cholesterol, triglyceride, serum high-density lipoprotein, cholesterol, serum low-density lipoprotein cholesterol, weight, height, BMI, waist circumference, and waist-to-hip ratio. The inclusion criteria of this study were post-menopausal women (45-65 years) in Pakistan. The confirmation of breast carcinoma was done through histopathology. Breast cancer occurrence was taken as a dependent variable, whereas BMI, central obesity, and lipid profile were taken as independent variables.

RESULTS

Studied risk factors (cholesterol, BMI, and central obesity) significantly correlated with breast cancer. Cholesterol has a significantly high positive correlation (0.646) with breast cancer. BMI has a positive significant correlation (0.491) with breast cancer, and central obesity has a low but positive significant correlation (0.266) with breast cancer. Moreover, the binary logistic regression model also showed a significant association between biochemical factors and breast cancer occurrence. Regression analysis depicted a linear relationship between a dependent variable (breast cancer occurrence) and independent variables (central obesity, cholesterol, BMI).

CONCLUSION

Postmenopausal overweight (central obesity), increased BMI and high cholesterol levels are major risk factors for breast cancer. Moreover, high total cholesterol proved to be the most significant risk marker for the occurrence of breast cancer in post-menopausal women of Pakistan.

Noise exposure and the risk of cancer: a comprehensive systematic review

The association between noise exposure and increased risk of cancer has received little attention in the field of research. Therefore, the goal of this study was to conduct a systematic review on the relationship between noise exposure and the incidence of cancer in humans. In this study, four electronic bibliographic databases including Scopus, PubMed, Web of Science, and Embase were systematically searched up to 21 April 2022. All types of noise exposure were considered, including environmental noise, occupational noise, and leisure or recreational noise. Furthermore, all types of cancers were studied, regardless of the organs involved. In total, 1836 articles were excluded on the basis of containing exclusion criteria or lacking inclusion criteria, leaving 19 articles retained for this study. Five of nine case-control studies showed a significant relationship between occupational or leisure noise exposure and acoustic neuroma. Moreover, four of five case-control and cohort studies indicated statistically significant relationships between environmental noise exposure and breast cancer. Of other cancer types, two case-control studies highlighted the risk of Hodgkin and non-Hodgkin lymphoma and two cohort studies identified an increased risk of colon cancer associated with environmental noise exposure. No relationship between road traffic and railway noise and the risk of prostate cancer was observed. In total, results showed that noise exposure, particularly prolonged and continuous exposure to loud noise, can lead to the incidence of some cancers. However, confirmation of this requires further epidemiological studies and exploration of the exact biological mechanism and pathway for these effects.

Decoding the Influence of Obesity on Prostate Cancer and Its Transgenerational Impact

In recent decades, the escalating prevalence of metabolic disorders, notably obesity and being overweight, has emerged as a pressing concern in public health. Projections for the future indicate a continual upward trajectory in obesity rates, primarily attributable to unhealthy dietary patterns and sedentary lifestyles. The ramifications of obesity extend beyond its visible manifestations, intricately weaving a web of hormonal dysregulation, chronic inflammation, and oxidative stress. This nexus of factors holds particular significance in the context of carcinogenesis, notably in the case of prostate cancer (PCa), which is a pervasive malignancy and a leading cause of mortality among men. A compelling hypothesis arises from the perspective of transgenerational inheritance, wherein genetic and epigenetic imprints associated with obesity may wield influence over the development of PCa. This review proposes a comprehensive exploration of the nuanced mechanisms through which obesity disrupts prostate homeostasis and serves as a catalyst for PCa initiation. Additionally, it delves into the intriguing interplay between the transgenerational transmission of both obesity-related traits and the predisposition to PCa. Drawing insights from a spectrum of sources, ranging from in vitro and animal model research to human studies, this review endeavors to discuss the intricate connections between obesity and PCa. However, the landscape remains partially obscured as the current state of knowledge unveils only fragments of the complex mechanisms linking these phenomena. As research advances, unraveling the associated factors and underlying mechanisms promises to unveil novel avenues for understanding and potentially mitigating the nexus between obesity and the development of PCa.

Unveiling the Immune Microenvironment's Role in Breast Cancer: A Glimpse into Promising Frontiers

Breast cancer (BC), one of the most widespread and devastating diseases affecting women worldwide, presents a significant public health challenge. This review explores the emerging frontiers of research focused on deciphering the intricate interplay between BC cells and the immune microenvironment. Understanding the role of the immune system in BC is critical as it holds promise for novel therapeutic approaches and precision medicine strategies. This review delves into the current literature regarding the immune microenvironment's contribution to BC initiation, progression, and metastasis. It examines the complex mechanisms by which BC cells interact with various immune cell populations, including tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs). Furthermore, this review highlights the impact of immune-related factors, such as cytokines and immune checkpoint molecules. Additionally, this comprehensive analysis sheds light on the potential biomarkers associated with the immune response in BC, enabling early diagnosis and prognostic assessment. The therapeutic implications of targeting the immune microenvironment are also explored, encompassing immunotherapeutic strategies and combination therapies to enhance treatment efficacy. The significance of this review lies in its potential to pave the way for novel therapeutic interventions, providing clinicians and researchers with essential knowledge to design targeted and personalized treatment regimens for BC patients.

Comparative efficacy of four exercise types on obesity-related outcomes in breast cancer survivors: A Bayesian network meta-analysis

PURPOSE

Exercise training is associated with improving the prognosis of breast cancer survivors, but no studies have evaluated the optimal exercise intervention. We aimed to investigate the most effective exercise intervention to improve obesity-related outcomes in breast cancer survivors.

METHODS

A comprehensive search strategy was conducted in Medline, Embase, Web of Science, Cochrane Library, and Chinese biomedical literature databases from the time of library construction to April 2, 2023. We included randomized controlled trials reporting the effects of four types of exercise interventions (aerobic exercise; aerobic combined with resitance exercise, resitstance exercise and mind-body exercise ) on obesity-related outcomes in breast cancer survivors. A Bayesian network meta-analysis was used to analyze and rank the effectiveness of four exercise types.

RESULTS

A total of 76 randomized controlled trials that contained 5610 breast cancer survivors were included. The treatment effect of combined aerobic and resistance exercise (mean difference = -0.59; 95% credible interval: 1.15, -0.08) was significantly better than that of the control groups in terms of body mass index. For percentage of body fat, combined aerobic and resistance exercise (mean difference = -1.74; 95% credible interval: 0.87, -0.90) and aerobic exercise (mean difference = -1.16; 95% credible interval: 2.15, -0.16) were significantly better than controls. Subgroup analysis suggested that combined aerobic and resistance exercise significantly affected body mass index at an intervention duration >12 weeks or weekly time on exercise >150 min.

CONCLUSION

Our network meta-analysis found combined aerobic and resistance exercise may be the most effective intervention to improve obesity-related outcomes in breast cancer survivors. In addition, intervention duration and participant adherence are important factors that influence the effectiveness of exercise interventions.

The Interrelationship between Obesity and Race in Breast Cancer Prognosis: A Prospective Cohort Study

Purpose

Obesity is associated with an increased breast cancer risk in postmenopausal women and may contribute to worse outcomes. Black women experience higher obesity and breast cancer mortality rates than non-Black women. We examined associations between race, obesity, and clinical tumor stage with breast cancer prognosis.

Methods

We conducted a prospective cohort study in 1,110 breast cancer patients, using univariable and multivariable Cox regression analyses to evaluate the effects of obesity, race/ethnicity, and clinical tumor stage on progression-free and overall survival (PFS and OS).

Results

22% of participants were Black, 64% were Hispanic White, and 14% were non-Hispanic White or another race. 39% of participants were obese (body mass index [BMI] ≥ 30 kg/m2). In univariable analyses, tumor stage III-IV was associated with worse PFS and OS compared to tumor stage 0-II (hazard ratio [HR] = 4.68, 95% confidence interval [CI] = 3.52-6.22 for PFS and HR = 5.92, 95% CI = 4.00-8.77 for OS). Multivariable analysis revealed an association between Black race and worse PFS in obese (HR = 2.19, 95% CI = 1.06-4.51) and non-obese (HR = 2.11, 95% CI = 1.05-4.21) women with tumors staged 0-II. Obesity alone was not associated with worse PFS or OS.

Conclusion

Results suggest a complex interrelationship between obesity and race in breast cancer prognosis. The association between Black race and worse PFS in tumor stages 0-II underscores the importance of early intervention in this group. Future studies are warranted to evaluate whether alternative measures of body composition and biomarkers are better prognostic indicators than BMI among Black breast cancer survivors.

Hypoxia inducible factor-1α (HIF-1α) in breast cancer: The crosstalk with oncogenic and onco-suppressor factors in regulation of cancer hallmarks

Low oxygen level at tumor microenvironment leads to a condition, known as hypoxia that is implicated in cancer progression. Upon hypoxia, HIF-1α undergoes activation and due to its oncogenic function and interaction with other molecular pathways, promotes tumor progression. The HIF-1α role in regulating breast cancer progression is described, Overall, HIF-1α has upregulation in breast tumor and due to its tumor-promoting function, its upregulation is in favor of breast tumor progression. HIF-1α overexpression prevents apoptosis in breast tumor and it promotes cell cycle progression. Silencing HIF-1α triggers cycle arrest and decreases growth. Migration of breast tumor enhances by HIF-1α signaling and it mainly induces EMT in providing metastasis. HIF-1α upregulation stimulates drug resistance and radio-resistance in breast tumor. Furthermore, HIF-1α signaling induces immune evasion of breast cancer. Berberine and pharmacological intervention suppress HIF-1α signaling in breast tumor and regulation of HIF-1α by non-coding RNAs occurs. Furthermore, HIF-1α is a biomarker in clinic.

The Molecular and Genetic Interactions between Obesity and Breast Cancer Risk

Breast cancer (BC) is considered the leading cause of death among females worldwide. Various risk factors contribute to BC development, such as age, genetics, reproductive factors, obesity, alcohol intake, and lifestyle. Obesity is considered to be a pandemic health problem globally, affecting millions of people worldwide. Obesity has been associated with a high risk of BC development. Determining the impact of obesity on BC development risk in women by demonstrating the molecular and genetic association in pre- and post-menopause females and risk to BC initiation is crucial in order to improve the diagnosis and prognosis of BC disease. In epidemiological studies, BC in premenopausal women was shown to be protective in a certain pattern. These altered effects between the two phases could be due to various physiological changes, such as estrogen/progesterone fluctuating levels. In addition, the relationship between BC risk and obesity is indicated by different molecular alterations as metabolic pathways and genetic mutation or epigenetic DNA changes supporting a strong connection between obesity and BC risk. However, these molecular and genetic alteration remain incompletely understood. The aim of this review is to highlight and elucidate the different molecular mechanisms and genetic changes occurring in obese women and their association with BC risk and development.

Leptin: A Heavyweight Player in Obesity-Related Cancers

Obesity, defined as the abnormal or excessive expansion of white adipose tissue, has reached pandemic proportions and is recognized as an important health concern since it is a common root for several comorbidities, including malignancies. Indeed, the current knowledge of the white adipose tissue, which shifts its role from an energy storage tissue to an important endocrine and metabolic organ, has opened up new avenues for the discovery of obesity's effects on tumor biology. In this review, we will report the epidemiological studies concerning the strong impact of obesity in several types of cancer and describe the mechanisms underlying the heterotypic signals between cancer cell lines and adipocytes, with particular emphasis on inflammation, the insulin/IGF-1 axis, and adipokines. Among the adipokines, we will further describe the in vitro, in vivo, and clinical data concerning the role of leptin, recognized as one of the most important mediators of obesity-associated cancers. In fact, leptin physiologically regulates energy metabolism, appetite, and reproduction, and several studies have also described the role of leptin in affecting cancer development and progression. Finally, we will summarize the newest pharmacological strategies aimed at mitigating the protumorigenic effects of leptin, underlining their mechanisms of action.

Association between high body mass index and prognosis of patients with early-stage breast cancer: A systematic review and meta-analysis

Background

A high body mass index (BMI) can indicate overweight or obesity and is a crucial risk factor for breast cancer survivors. However, the association between high BMI and prognosis in early-stage breast cancer (EBC) remains unclear. We aimed to assess the effects of high BMI on the prognosis of patients with EBC.

Methods

The PubMed, Embase, and Cochrane Library databases and proceedings of major oncological conferences related to the effects of BMI on the prognosis of breast cancer were searched up to November 2021. Fixed- and random-effects models were used for meta-analyses. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) for disease-free survival (DFS) and overall survival (OS) were extracted from the included literature.

Results

Twenty retrospective cohort studies with 33,836 patients with EBC were included. Overweight patients had worse DFS (HR: 1.16, 95% CI: 1.05-1.27, P = 0.002) and OS (HR: 1.20; 95% CI: 1.09-1.33, P < 0.001). Obesity also had adverse effects on DFS (HR: 1.17, 95% CI: 1.07-1.29, P = 0.001) and OS (HR: 1.30, 95% CI: 1.17-1.45, P < 0.001). Likewise, patients with high BMI had worse DFS (HR: 1.16, 95% CI: 1.08-1.26, P < 0.001) and OS (HR: 1.25, 95% CI: 1.14-1.39, P < 0.001). In subgroup analyses, overweight had adverse effects on DFS (HR: 1.11, 95% CI: 1.04-1.18, P = 0.001) and OS (HR: 1.18, 95% CI: 1.11-1.26, P < 0.001) in multivariate analyses, whereas the relationship that overweight had negative effects on DFS (HR: 1.21, 95% CI: 0.99-1.48, P = 0.058) and OS (HR: 1.39, 95% CI: 0.92-2.10, P = 0.123) was not statistically significant in univariate analysis. By contrast, obesity had adverse effects on DFS (HR: 1.21, 95% CI: 1.06-1.38, P = 0.004 and HR: 1.14, 95% CI: 1.08-1.22, P < 0.001) and OS (HR: 1.33, 95% CI: 1.15-1.54, P < 0.001 and HR: 1.23, 95% CI: 1.15-1.31, P < 0.001) in univariate and multivariate analyses, respectively.

Conclusions

Compared with normal weight, increased body weight (overweight, obesity, and high BMI) led to worse DFS and OS in patients with EBC. Once validated, these results should be considered in the development of prevention programs.

CEBP-β and PLK1 as Potential Mediators of the Breast Cancer/Obesity Crosstalk: In Vitro and In Silico Analyses

Over the last two decades, obesity has reached pandemic proportions in several countries, and expanding evidence is showing its contribution to several types of malignancies, including breast cancer (BC). The conditioned medium (CM) from mature adipocytes contains a complex of secretes that may mimic the obesity condition in studies on BC cell lines conducted in vitro. Here, we report a transcriptomic analysis on MCF-7 BC cells exposed to adipocyte-derived CM and focus on the predictive functional relevance that CM-affected pathways/processes and related biomarkers (BMs) may have in BC response to obesity. CM was demonstrated to increase cell proliferation, motility and invasion as well as broadly alter the transcript profiles of MCF-7 cells by significantly modulating 364 genes. Bioinformatic functional analyses unraveled the presence of five highly relevant central hubs in the direct interaction networks (DIN), and Kaplan-Meier analysis sorted the CCAAT/enhancer binding protein beta (CEBP-β) and serine/threonine-protein kinase PLK1 (PLK1) as clinically significant biomarkers in BC. Indeed, CEBP-β and PLK1 negatively correlated with BC overall survival and were up-regulated by adipocyte-derived CM. In addition to their known involvement in cell proliferation and tumor progression, our work suggests them as a possible "deus ex machina" in BC response to fat tissue humoral products in obese women.

Reversion of breast epithelial polarity alterations caused by obesity

Molecular links between breast cancer risk factors and pro-oncogenic tissue alterations are poorly understood. The goal of this study was to characterize the impact of overweight and obesity on tissue markers of risk, using normal breast biopsies, a mouse model of diet-induced obesity, and cultured breast acini. Proliferation and alteration of epithelial polarity, both necessary for tumor initiation, were quantified by immunostaining. High BMI (>30) and elevated leptin were associated with compromised epithelial polarity whereas overweight was associated with a modest increase in proliferation in human and mice mammary glands. Human serum with unfavorable adipokine levels altered epithelial polarization of cultured acini, recapitulating the effect of leptin. Weight loss in mice led to metabolic improvements and restored epithelial polarity. In acini cultures, alteration of epithelial polarity was prevented by antioxidants and could be reverted by normalizing culture conditions. This study shows that obesity and/or dietary factors modulate tissue markers of risk. It provides a framework to set target values for metabolic improvements and to assess the efficacy of interventional studies aimed at reducing breast cancer risk.

Association of Serum Leptin With Body Mass Index in Gallbladder Cancer Patients: A Pilot Study

BACKGROUND

Leptin has been proposed to be a link between obesity and the increased incidence of various cancers like breast cancer, colon cancer, gastric cancer, etc. The role of leptin in gallbladder cancer is largely undetermined. Moreover, no study has evaluated serum leptin levels and their correlation with clinicopathological characteristics and serum tumour markers in gallbladder cancer (GBC). Therefore, the present study was planned.

METHODS

A cross-sectional study was conducted in a tertiary care hospital in Northern India after obtaining ethical approval from the institution. Forty GBC patients staged as per American Joint Committee on Cancer (AJCC) 8th staging system were recruited along with 40 healthy controls. Serum leptin was assayed by sandwich enzyme-linked immunosorbent assay (ELISA) and tumour markers (CA19-9, CEA and CA125) by Chemiluminescence. ROC, Mann Whitney U test, Linear regression and Spearman correlation was performed using Statistical Product and Service Solutions (SPSS) (IBM SPSS Statistics for Windows, Version 25.0, Armonk, NY). BMI was also assessed for both groups.

RESULTS

Median BMI for GBC patients was 19.46 (IQR 17.61-22.36). Median serum leptin levels were significantly lower (2.09 (IQR 1.01-7.76) ng/mL) in GBC patients as compared to controls (12.32 (IQR 10.50-14.72) ng/mL). AUC was 0.84 with 100% sensitivity and 75% specificity at 7.57 ng/mL. Serum leptin was not associated with cancer stage, resectability, metastasis, liver infiltration, or tumour markers on linear regression (p=0.74, adjusted R square = -0.07). A significant positive correlation was found between BMI and serum leptin in GBC patients (p=0.00).

CONCLUSIONS

Lower BMI and relatively lean presentation of GBC patients may account for low serum leptin levels.

Association between metabolic syndrome, insulin resistance, and IGF-1 in breast cancer survivors of DIANA-5 study

PURPOSE

Circulating insulin-like growth factor-1 (IGF-1) is positively associated with the risk of BC recurrence, and is more frequently dysregulated in older people, especially in those with metabolic syndrome (MetS) and obesity. This study aimed to analyze the association between IGF-1 levels and indices of MetS and insulin resistance in BC survivors.

METHODS

Baseline data of 563 BC survivors enrolled in the DIet and ANdrogen-5 (DIANA-5; NCT05019989) study were analyzed.

RESULTS

Lower circulating IGF-1 levels in subjects with MetS than in those without MetS were found. After stratification of the patients according to the diagnosis of MetS, we highlighted that the insulin was the main predictor of elevated IGF-1 levels only in subjects without MetS. Moreover, we found an interaction between high-density lipoprotein cholesterol (HDL-C), glycemia, and IGF-1 levels, showing a positive correlation between HDL-C and IGF-1, especially in subjects with higher values of glycemia and without a diagnosis of MetS.

CONCLUSIONS

While IGF-1 levels appear to be much more impaired in subjects diagnosed with MetS, in non-MetS subjects, IGF-1 levels may respond better to metabolic parameters and lifestyle changes. Further studies are needed to analyze the role of physical activity and/or dietary intervention in modulating IGF-1 concentrations in BC survivors.

IMPLICATIONS FOR CANCER SURVIVORS

These results could have important clinical implications for planning customized strategies aimed at modulating IGF-1 levels in BC survivors. In fact, while the IGF-1 system seems to be much more compromised in subjects with a diagnosis of MetS, in noMetS subjects, IGF-1 levels could better respond to lifestyle changes.

Analysis of circulating extracellular vesicle derived microRNAs in breast cancer patients with obesity: a potential role for Let-7a

BACKGROUND

The incidence of obesity, a known risk factor for several metabolic and chronic diseases, including numerous malignancies, has risen sharply in the world. Various clinical studies demonstrate that excessive Body Mass Index (BMI) may worsen the incidence, prognosis, and mortality rates of breast cancer. Thus, understanding the link tying up obesity and breast cancer onset and progression is critically important, as it can impact patients' survival and quality of life. Recently, circulating extracellular vesicle (EV) derived miRNAs have attracted much attention for their diagnostic, prognostic and therapeutic potential in oncology research. Although the potential role of EV-derived miRNAs in the early detection of breast cancer has been repeatedly mentioned, screening of miRNAs packaged within serum EVs has not yet been reported in patients with obesity.

METHODS

Circulating EVs were isolated from normal weight (NW), and overweight/obese (OW/Ob) breast cancer patients and characterized by Transmission Electron Microscopy (TEM), Nanoparticle Tracking Analysis (NTA), and protein marker expression. Evaluation of EV-associated miRNAs was conducted in a screening (RNA-seq) and a validation (qRT-PCR) cohort. Bioinformatic analysis was performed to uncover significantly enriched biological processes, molecular functions and pathways. ROC and Kaplain-Meier survival analyses were used for clinical significance.

RESULTS

Comparison of serum EV-derived miRNAs from NW and OW/Ob patients detected seven differentially expressed miRNAs (let-7a-5p, miR-122-5p, miR-30d-5p, miR-126-3p, miR-27b-3p, miR-4772-3p, and miR-10a-5p) in the screening cohort. GO analysis revealed the enrichment of protein phosphorylation, intracellular signal transduction, signal transduction, and vesicle-mediated transport among the top biological processes. In addition, the target genes were significantly enriched in pathways related to PI3K/Akt, growth hormones, and insulin signalings, which are all involved in obesity-related diseases and/or breast cancer progression. In the validation cohort, qRT-PCR confirmed a significant down-regulation of EV-derived let-7a in the serum of OW/Ob breast cancer patients compared to NW patients. Let-7a levels also exhibited a negative correlation with BMI values. Importantly, decreased let-7a miRNA expression was associated with higher tumor grade and poor survival in patients with breast cancer.

CONCLUSION

These results suggest that serum-EV derived miRNAs may reflect a differential profile in relation to a patient's BMI, which, once validated in larger cohorts of patients, could provide insights into novel specific biomarkers and innovative targets to prevent the progression of obesity-mediated breast cancer.

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.

The level of kinesiophobia in breast cancer women undergoing surgical treatment

Introduction

Lifestyle-associated factors like physical activity (PA) play an important role in cancer prevention and oncology treatment outcomes. The aim of the study is to investigate the level of kinesiophobia (fear of movement) in breast cancer (BC) patients undergoing surgical treatment depending on socio-demographic variables, lifestyle before cancer diagnosis, stage and type of BC and comorbidities.

Methods

We interviewed 285 women (132 patients from Greater Poland Cancer Center - age: 55.7 ± 12.4; BMI: 26.7 ± 4.7 and 153 healthy women from control group - age: 49.0 ± 15.7; BMI: 25.7 ± 4.0) using Polish adaptation of the Tampa Scale of Kinesiophobia (TSK).

Results

Research results show that women with BC suffer from kinesiophobia (>37 points) signi!cantly. Approximately 3/4 of the surveyed women with BC did not know the World Health Organization (WHO) recommendations regarding the weekly dose of PA for healthy people and for people with cancer. Before cancer diagnosis more than a half of women (60%) performed PA in accordance with WHO recommendations. 7% less women performed PA during oncology treatment. Almost a half of patients are not physically active during cancer treatment and 1/5 of the respondents declared that they do not know yet if they will be physically active after oncology treatment. The level of kinesiophobia in BC women with comorbidities was the same as in the group of BC women without comorbidities. However, the highest levels of fear of movement have been observed among women with BC suffering also from osteoporosis, obesity and diabetes. In general, higher levels of kinesiophobia were reported among women in less advanced stages of the disease. There were no differences in the level of kinesiophobia depending on the type of BC (hormonally dependent luminal cancers vs. other types). The level of kinesiophobia did not differ between women who were physically active before BC diagnosis and women who were not. In terms of socio- demographic variables, we found one direct association between the level of kinesiophobia (pain) with age - the greater age, the higher level of pain kinesiophobia.

Discussion

Research on fear of movement in female oncology requires further research (including also chemotherapy, radiotherapy, immunotherapy and hormonal therapy) and in order to effectively eliminate hypokinetic attitudes at every stage of cancer treatment.

Vaspin accelerates the proliferation, invasion and metastasis of Triple-Negative breast cancer through MiR-33a-5p/ABHD2

OBJECTIVE

To explore the influence and the underlying mechanism of vaspin (visceral adipose tissue-derived serpin) on the development of triple-negative breast malignancy.

METHODS

First, we analyzed medical records and screened out 22 breast cancer patients with different BMI according to inclusion and exclusion criterion, and measured serum vaspin of those patients. Then we studied the effects of vaspin on TNBC cell lines by using EdU assay, colony formation, transwell and wound-healing assay. Later, we used bioinformatics analysis to identify downstream effectors and verify with qRT-PCR, luciferase assay, western blot, etc. RESULTS: We found the vaspin level was positively correlated with BMI in breast malignant patients and vaspin could significantly enhance the proliferation, infiltration and transferring of triple-negative breast cancer cells by restraining the expression of miR-33a-5p. By using bioinformatic analysis and luciferase assay, we identified miR-33a-5p directly regulating ABHD2.

CONCLUSION

Vaspin, as a cancer-promoting cytokine, may inhibit miR-33a-5p thus increasing the level of ABHD2 to promote the development of the triple-negative breast cancer.

Diversity and heterogeneity in human breast cancer adipose tissue revealed at single-nucleus resolution

Introduction

There is increasing awareness of the role of adipose tissue in breast cancer occurrence and development, but no comparison of adipose adjacent to breast cancer tissues and adipose adjacent to normal breast tissues has been reported.

Methods

Single-nucleus RNA sequencing (snRNA-seq) was used to analyze cancer-adjacent and normal adipose tissues from the same breast cancer patient to characterize heterogeneity. SnRNA-seq was performed on 54513 cells from six samples of normal breast adipose tissue (N) distant from the tumor and tumor-adjacent adipose tissue (T) from the three patients (all surgically resected).

Results and discussion

Significant diversity was detected in cell subgroups, differentiation status and, gene expression profiles. Breast cancer induces inflammatory gene profiles in most adipose cell types, such as macrophages, endothelial cells, and adipocytes. Furthermore, breast cancer decreased lipid uptake and the lipolytic phenotype and caused a switch to lipid biosynthesis and an inflammatory state in adipocytes. The in vivo trajectory of adipogenesis revealed distinct transcriptional stages. Breast cancer induced reprogramming across many cell types in breast cancer adipose tissues. Cellular remodeling was investigated by alterations in cell proportions, transcriptional profiles and cell-cell interactions. Breast cancer biology and novel biomarkers and therapy targets may be exposed.

Adipocytokine imbalance and breast cancer in obese women

CONTEXT

Breast cancer is the most common diagnosis established in women with malignant tumors.

AIMS

The purpose is to investigate the blood contents of adiponectin and leptin in women with breast cancer and obesity.

SETTINGS AND DESIGN

A total of 140 women aged 40-50 were examined.

MATERIALS AND METHODS

Group 1 included 70 women from classes 1 or 2 obesity. Group 2 included 70 women with stage 1 or 2 breast cancer and classes 1 or 2 obesity. The control group included 30 apparently healthy women, with mean age of 42.5 ± 2.5 years.

STATISTICAL ANALYSIS USED

Statistical processing of the results obtained was performed using Statistica.

RESULTS

Groups 1 and 2 were statistically significantly different from each other across all parameters, except for leptin resistance. In group 2, the course of breast cancer with concomitant obesity is characterized by disrupted adipocytokine homeostasis, which manifests as a 1.94-fold decrease in the blood content of adiponectin (P < 0.05), a 4.14-fold increase in the blood content of leptin (P < 0.05), and an 8.00-fold increase in the leptin/adiponectin ratio (P < 0.05). Poorly differentiated breast tumors exhibit a more pronounced imbalance in the blood levels of adipocytokines. Thus, the serum content of leptin in women with poorly differentiated tumors (G3) was 1.79 times (P < 0.05) higher than in women with moderately differentiated tumors (G2).

CONCLUSIONS

The course of breast cancer with concomitant obesity is characterized by disrupted adipocytokine homeostasis and decreased adiponectin concentration in the blood.

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.

Obese mammary tumour-bearing mice are highly sensitive to doxorubicin-induced hepatotoxicity

BACKGROUND

Breast cancer is a major health burden for women, worldwide. Lifestyle-related risk factors, such as obesity and being overweight, have reached epidemic proportions and contributes to the development of breast cancer. Doxorubicin (DXR) is a chemotherapeutic drug commonly used to treat breast cancer, and although effective, may cause toxicity to other organs. The mechanisms and effects of DXR on hepatic tissue, and the contributing role of obesity, in breast cancer patients are poorly understood. The aim of this study was therefore to investigate the effects of DXR on hepatic tissue in an obese tumour-bearing mouse model.

METHODS

A diet-induced obesity (DIO) mouse model was established, where seventy-four three-week-old female C57BL6 mice were divided into two main groups, namely the high fat diet (containing 60% kcal fat) and standard diet (containing 10% kcal fat) groups. After eight weeks on their respective diets, the DIO phenotype was established, and the mice were further divided into tumour and non-tumour groups. Mice were subcutaneously inoculated with E0771 triple negative breast cancer cells in the fourth mammary gland and received three doses of 4 mg/kg DXR (cumulative dosage of 12 mg/kg) or vehicle treatments via intraperitoneal injection. The expression levels of markers involved in apoptosis and alanine aminotransferase (ALT) were compared by means of western blotting. To assess the pathology and morphology of hepatic tissue, haematoxylin and eosin staining was performed. The presence of fibrosis and lipid accumulation in hepatic tissues were assessed with Masson's trichrome and Oil Red O staining, respectively.

RESULTS

Microscopic examination of liver tissues showed significant changes in the high fat diet tumour-bearing mice treated with DXR, consisting of macrovesicular steatosis, hepatocyte ballooning and lobular inflammation, compared to the standard diet tumour-bearing mice treated with DXR and the control group (standard diet mice). These changes are the hallmarks of non-alcoholic fatty liver disease, associated with obesity.

CONCLUSION

The histopathological findings indicated that DXR caused significant hepatic parenchymal injury in the obese tumour-bearing mice. Hepatotoxicity is aggravated in obesity as an underlying co-morbidity. It has been shown that obesity is associated with poor clinical outcomes in patients receiving neo-adjuvant chemotherapy treatment regimens.

Kinesiophobia among Breast Cancer Survivors One Year after Hospital Treatment

Breast cancer (BC) is one of the most dangerous health problems affecting women. Lifestyle-associated determinants like physical activity (PA) play an important role in BC treatment outcomes. Studies suggest that oncology patients are insufficiently physically active. One of the potential barriers is kinesiophobia-fear of movement due to expected pain and fatigue. The aim of this cross-sectional study is to investigate the level of kinesiophobia among women one year after BC hospital treatment depending on socio-demographic variables, stage and type of BC, lifestyle, and comorbidities. Polish women after BC (n = 138, age 46.5 ± 9.2, BMI 24.6 ± 4.0) participated in the study and the Tampa Scale of Kinesiophobia (TSK) questionnaire was used in the diagnostic survey. The study results show that women suffer from kinesiophobia after BC. Moreover, every third woman (32.6%) does not practice sport regularly one year after BC treatment. The lifestyle before BC diagnosis impacts the level of kinesiophobia after treatment-women who were not physically active before BC diagnosis declared higher levels than previously active women. The study result shows that a high level of kinesiophobia correlates with a low level of PA among women after BC. Women with obesity and diabetes also declared higher levels of kinesiophobia than women without comorbidities. The type and stage of BC have no influence on the level of kinesiophobia; however, in terms of socio-demographic variables, a direct association between kinesiophobia and age has been found-the greater the age, the higher the level of kinesiophobia. Further research on fear of movement in oncology is required in order to effectively eliminate hypokinetic attitudes in every type of female and male cancer.

Proteomic Profiling of Extracellular Vesicles Released by Leptin-Treated Breast Cancer Cells: A Potential Role in Cancer Metabolism

Tumor extracellular vesicles (EVs), as endocytic vesicles able to transport nucleic acids, proteins, and metabolites in recipient cells, have been recognized fundamental mediators of cell-to-cell communication in breast cancer. The biogenesis and release of EVs are highly regulated processes and both the quantity of EVs and their molecular cargo might reflect the metabolic state of the producing cells. We recently demonstrated that the adipokine leptin, whose circulating levels correlate with adipose tissue expansion, is an inducer of EV release from breast cancer cells. Here, we show a specific proteomic signature of EVs released by MCF-7 breast cancer cells grown in the presence of leptin (Lep-EVs), in attempt to find additional molecular effectors linking obesity to breast cancer biology. An analysis of the proteomic profile of Lep-EVs by LC-MS/MS revealed a significant enrichment in biological processes, molecular functions, and cellular components mainly related to mitochondrial machineries and activity, compared to protein content of EVs from untreated breast cancer cells. Metabolic investigations, carried out to assess the autocrine effects of these vesicles on breast cancer cells, revealed that Lep-EVs were able to increase ATP levels in breast cancer cells. This result is associated with increased mitochondrial respiration evaluated by Seahorse analyzer, supporting the concept that Lep-EVs can modulate MCF-7 breast cancer cell oxidative metabolism. Moreover, taking into account the relevance of tumor immune cell crosstalk in the tumor microenvironment (TME), we analyzed the impact of these vesicles on macrophage polarization, the most abundant immune component in the breast TME. We found that tumor-derived Lep-EVs sustain the polarization of M0 macrophages, derived from the human THP-1 monocytic cells, into M2-like tumor-associated macrophages, in terms of metabolic features, phagocytic activity, and increased expression of CD206-positive population. Overall, our results indicate that leptin by inducing the release of EV-enriched in mitochondrial proteins may control the metabolism of MCF-7 breast cancer cells as well as that of macrophages. Characterization of tumor-derived EV protein cargo in an obesity-associated milieu, such as in the presence of elevated leptin levels, might allow identifying unique features and specific metabolic mechanisms useful to develop novel therapeutic approaches for treatment of breast cancer, especially in obese patients.

Psychological suppressive profile and autoantibodies variability in women living with breast cancer: A prospective cross-sectional study

Breast cancer (BC) is a leading cause of women's morbimortality worldwide. Unfortunately, attempts to predict women's susceptibility to developing BC well before it becomes symptomatic, based on their genetic, family, and reproductive background have proved unsatisfactory. Here we analyze the matching of personality traits and protein serum profiles to predict women's susceptibility to developing cancer. We conducted a prospective study among 150 women (aged 18-70 years), who were distributed into three groups (n = 50): women without breast pathology and women diagnosed with BC or benign breast pathology. Psychological data were obtained through standardized psychological tests and serum protein samples were analyzed through semiquantitative protein immunoblotting. The matching for psychological and immunological profiles was constructed from these data using a mathematical generalized linear model.The model predicted that women who have stronger associations between high-intensity stress responses, emotional containment, and an increased number and reduced variability of serum proteins (detected by IgG autoantibodies) have the greatest susceptibility to develop BC before the disease has manifested clinically. Hence, the present study endorses the possibility of using psychological and biochemical tests in combination to increase the possibility of identifying women at risk of developing BC before the disease shows clinical manifestations. A longitudinal study must be instrumented to test the prediction ability of the instrument in real scenarios.

Trial registration

Committee of Ethical Research of the Hospital General de México "Dr. Eduardo Liceaga," Ministry of Health (DI/12/111/03/064).

The Effects of BMI and Genetic Variation of Adipokines on Serum Concentrations of Hormones in Untreated Individuals with Breast Cancer; a Pilot Study

Background: Numerous studies have shown an association between hormones secreted by adipose tissues and cancer development. Objectives: This study aimed at investigating the effect of body mass index (BMI) and genetic variation of leptin and adiponectin on serum concentrations of leptin, adiponectin, and estradiol among untreated breast cancer. Methods: This case-control study was performed on 350 women (175 women with breast cancer and 175 healthy controls), who had not taken any medications. Serum levels of estradiol (17-beta estradiol), leptin, and adiponectin were measured, using the ELISA technique. Single-nucleotide polymorphisms of leptin gene (LepG2548A), leptin receptor (Q223, K109R, and K656N), and adiponectin gene (T45G, G276T, C11377G, and 11391A) in blood-isolated DNA were evaluated, using RFLP-PCR technique. Results: Body mass index can affect serum concentrations of hormones and is associated with breast cancer. Also, except for adiponectin C11377G polymorphism, other all genetic variations showed significant relationships with breast cancer. In both groups, BMI was significantly correlated with the mean serum concentrations of hormones, and the risk of breast cancer increased in G2548A, Q223R, K656N, and G276T polymorphisms. The effect of risk allele genotypes on serum concentration of hormones showed that changes in serum concentration of estrogen and leptin in all studied polymorphisms were associated with breast cancer in postmenopausal women. But adiponectin level was only affected by polymorphisms K109R, K656N, and G276 and G11391A. Conclusions: High BMI and genetic variation can affect cancer development by changing the serum concentrations of hormones in different genotypes. Studying various populations’ genetics and lifestyle can help definitive conclusions about genetics and obesity.

Insight on the Role of Leptin: A Bridge from Obesity to Breast Cancer

Leptin is a peptide hormone, mainly known for its role as a mediator of adipose tissue endocrine functions, such as appetite control and energy homeostasis. In addition, leptin signaling is involved in several physiological processes as modulation of innate and adaptive immune responses and regulation of sex hormone levels. When adipose tissue expands, an imbalance of adipokines secretion may occur and increasing leptin levels contribute to promoting a chronic inflammatory state, which is largely acknowledged as a hallmark of cancer. Indeed, upon binding its receptor (LEPR), leptin activates several oncogenic pathways, such as JAK/STAT, MAPK, and PI3K/AKT, and seems to affect cancer immune response by inducing a proinflammatory immune polarization and eventually enhancing T-cell exhaustion. In particular, obesity-associated hyperleptinemia has been related to breast cancer risk development, although the underlying mechanism is yet to be completely clarified and needs to be deemed in light of multiple variables, such as menopausal state and immune response. The aim of this review is to provide an overview of the potential role of leptin as a bridge between obesity and breast cancer and to establish the physio-pathological basis of the linkage between these major health concerns in order to identify appropriate and novel therapeutic strategies to adopt in daily clinical practice.

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.

Radiogenomics analysis reveals the associations of dynamic contrast-enhanced–MRI features with gene expression characteristics, PAM50 subtypes, and prognosis of breast cancer

Background

To investigate reliable associations between dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) features and gene expression characteristics in breast cancer (BC) and to develop and validate classifiers for predicting PAM50 subtypes and prognosis from DCE-MRI non-invasively.

Methods

Two radiogenomics cohorts with paired DCE-MRI and RNA-sequencing (RNA-seq) data were collected from local and public databases and divided into discovery (n = 174) and validation cohorts (n = 72). Six external datasets (n = 1,443) were used for prognostic validation. Spatial–temporal features of DCE-MRI were extracted, normalized properly, and associated with gene expression to identify the imaging features that can indicate subtypes and prognosis.

Results

Expression of genes including RBP4, MYBL2, and LINC00993 correlated significantly with DCE-MRI features (q-value < 0.05). Importantly, genes in the cell cycle pathway exhibited a significant association with imaging features (p-value < 0.001). With eight imaging-associated genes (CHEK1, TTK, CDC45, BUB1B, PLK1, E2F1, CDC20, and CDC25A), we developed a radiogenomics prognostic signature that can distinguish BC outcomes in multiple datasets well. High expression of the signature indicated a poor prognosis (p-values < 0.01). Based on DCE-MRI features, we established classifiers to predict BC clinical receptors, PAM50 subtypes, and prognostic gene sets. The imaging-based machine learning classifiers performed well in the independent dataset (areas under the receiver operating characteristic curve (AUCs) of 0.8361, 0.809, 0.7742, and 0.7277 for estrogen receptor (ER), human epidermal growth factor receptor 2 (HER2)-enriched, basal-like, and obtained radiogenomics signature). Furthermore, we developed a prognostic model directly using DCE-MRI features (p-value < 0.0001).

Conclusions

Our results identified the DCE-MRI features that are robust and associated with the gene expression in BC and displayed the possibility of using the features to predict clinical receptors and PAM50 subtypes and to indicate BC prognosis.

The obesity-breast cancer link: a multidisciplinary perspective

Obesity, exceptionally prevalent in the USA, promotes the incidence and progression of numerous cancer types including breast cancer. Complex, interacting metabolic and immune dysregulation marks the development of both breast cancer and obesity. Obesity promotes chronic low-grade inflammation, particularly in white adipose tissue, which drives immune dysfunction marked by increased pro-inflammatory cytokine production, alternative macrophage activation, and reduced T cell function. Breast tissue is predominantly composed of white adipose, and developing breast cancer readily and directly interacts with cells and signals from adipose remodeled by obesity. This review discusses the biological mechanisms through which obesity promotes breast cancer, the role of obesity in breast cancer health disparities, and dietary interventions to mitigate the adverse effects of obesity on breast cancer. We detail the intersection of obesity and breast cancer, with an emphasis on the shared and unique patterns of immune dysregulation in these disease processes. We have highlighted key areas of breast cancer biology exacerbated by obesity, including incidence, progression, and therapeutic response. We posit that interception of obesity-driven breast cancer will require interventions that limit protumor signaling from obese adipose tissue and that consider genetic, structural, and social determinants of the obesity–breast cancer link. Finally, we detail the evidence for various dietary interventions to offset obesity effects in clinical and preclinical studies of breast cancer. In light of the strong associations between obesity and breast cancer and the rising rates of obesity in many parts of the world, the development of effective, safe, well-tolerated, and equitable interventions to limit the burden of obesity on breast cancer are urgently needed.

Type I IFN stimulates IFI16-mediated aromatase expression in adipocytes that promotes E2-dependent growth of ER-positive breast cancer

Although type I interferons (IFNs) play multifaceted roles during tumorigenesis and cancer treatment, the interplay between type I IFNs and estrogen signaling in breast cancer (BC) microenvironment is not well understood. Here, we report a novel function of type I IFNs in inducing aromatase expression in adipose tissues surrounding BC, which potentiates the E₂-dependent growth of estrogen receptor (ER)-positive BC. First, we found that expression levels of type I IFNs correlate negatively with clinical outcome but positively with tumor grade in patients with ER-positive BC. Levels of type I IFNs were elevated in cocultured media of immune cells and BC cells, which increased aromatase expression and E₂ production in Simpson-Golabi-Behmel syndrome preadipocytes. The type I IFN-induced aromatase expression was dependent on IFN-γ-inducible protein 16 (IFI16), which is encoded by an interferon-stimulated gene. At the molecular level, type I IFNs led to recruitment of HIF1α-IFI16-PRMT2 complex to the hypoxia-response element located in the aromatase PI.3/PII promoter. Next, we generated an adipocyte-specific Ifi204, which is a mouse ortholog of human IFI16, knockout mouse (Ifi204-AKO). IFNβ induced E₂ production in the preadipocytes isolated from the control mice, but such E₂ production was far lower in the Ifi204-AKO preadipocytes. Importantly, the growth of orthotopically inoculated E0771 ER-positive mammary tumors was reduced significantly in the Ifi204-AKO mice. Taken together, our findings provide novel insights into the crosstalk between type I IFNs and estrogen signaling in the progression of ER-positive BC.

Obesity modulates the immune macroenvironment associated with breast cancer development

Growing evidence demonstrates a strong correlation between obesity and an increased risk of breast cancer, although the mechanisms involved have not been completely elucidated. Some reports have described a crosstalk between adipocytes, cancer cells, and immune cells within the tumor microenvironment, however, it is currently unknown whether obesity can promote tumor growth by inducing systemic alterations of the immune cell homeostasis in peripheral lymphoid organs and adipose tissue. Here, we used the E0771 breast cancer cell line in a mouse model of diet-induced obesity to analyze the immune subpopulations present in the tumors, visceral adipose tissue (VAT), and spleen of lean and obese mice. Our results showed a significant reduction in the frequency of infiltrating CD8⁺ T cells and a decreased M1/M2 macrophage ratio, indicative of the compromised anti-tumoral immune response reported in obesity. Despite not finding differences in the percentage or numbers of intratumoral Tregs, phenotypic analysis showed that they were enriched in CD39⁺, PD-1⁺ and CCR8⁺ cells, compared to the draining lymph nodes, confirming the highly immunosuppressive profile of infiltrating Tregs reported in established tumors. Analysis of peripheral T lymphocytes showed that tumor development in obese mice was associated to a significant increase in the percentage of peripheral Tregs, which supports the systemic immunosuppressive effect caused by the tumor. Interestingly, evaluation of immune subpopulations in the VAT showed that the characteristic increase in the M1/M2 macrophage ratio reported in obesity, was completely reversed in tumor-bearing mice, resembling the M2-polarized profile found in the microenvironment of the growing tumor. Importantly, VAT Tregs, which are commonly decreased in obese mice, were significantly increased in the presence of breast tumors and displayed significantly higher levels of Foxp3, indicating a regulatory feedback mechanism triggered by tumor growth. Altogether, our results identify a complex reciprocal relationship between adipocytes, immune cells, and the tumor, which may modulate the immune macroenvironment that promotes breast cancer development in obesity.

A pooled case-only analysis of obesity and breast cancer subtype among Black women in the southeastern United States

PURPOSE

To evaluate the association between obesity and the relative prevalence of tumor subtypes among Black women with breast cancer (BC).

METHODS

We conducted a pooled case-only analysis of 1,793 Black women with invasive BC recruited through three existing studies in the southeastern US. Multivariable case-only polytomous logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between obesity, measured by pre-diagnostic body mass index (BMI), and human epidermal growth factor receptor 2 + (HER2 +) and triple negative BC (TNBC) subtype relative to hormone receptor (HR) + /HER2- status (referent).

RESULTS

Among 359 premenopausal women, 55.4% of cases were HR + /HER2 -, 20.1% were HER2 + , and 24.5% were TNBC; corresponding percentages among 1,434 postmenopausal women were 59.3%, 17.0%, and 23.6%. Approximately, 50-60% of both pre- and postmenopausal women were obese (BMI > 30 kg/m²), regardless of BC subtype. We did not observe a significant association between obesity and BC subtype. Among postmenopausal women, class I obesity (BMI 35 + kg/m²) was not associated with the development of HER2 + BC (OR 0.69; 95% CI 0.42-1.14) or TNBC (OR 0.93; 95% CI 0.60-1.45) relative to HR + /HER2- tumors. Corresponding estimates among premenopausal women were 1.03 (95% CI 0.43-2.48) and 1.13 (95% CI 0.48-2.64).

CONCLUSION

In this large study of Black women with BC, there was no evidence of heterogeneity of BMI by BC subtype.

Chronic Leptin Treatment Induces Epithelial-Mesenchymal Transition in MCF10A Mammary Epithelial Cells

Leptin is a cytokine-like hormone that functions as a link between obesity and breast cancer (BC). Leptin treatment induces Epithelial to Mesenchymal Transition (EMT) in BC cell lines. In non-tumoral breast epithelial MCF10A cells, acute leptin treatment induces partial EMT. However, the effect of chronic leptin treatment on EMT in non-tumorigenic breast cells has not been fully explored. This study aimed to evaluate the effect of chronic leptin treatment on the induction of EMT in MCF10A cells. We found that chronic leptin treatment induces a switch from an epithelial to a mesenchymal morphology, partial loss of E-cadherin and gain of vimentin expression. Immunolocalization experiments showed a partial loss of E-cadherin at cell junctions and increased cytoplasmic localization of vimentin in leptin-treated cells. Moreover, chronic leptin treatment increased collective cell migration and invasion. Furthermore, when cultured in non-adherent conditions leptin treated cells exhibited reduced cell aggregation, increased survival, and decreased apoptosis, which correlates with increased FAK and AKT phosphorylation. Finally, bioinformatic analysis in two publicly available RNAseq datasets from normal breast tissue shows that high levels of leptin mRNA correlate positively with the expression of mesenchymal markers, and negatively with epithelial markers. Thus, our results demonstrate that chronic leptin treatment induces EMT in non-tumorigenic MCF10A cells and suggest that high leptin expression in normal breast tissue may induce EMT and contribute to increased risk 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.

Assessment of causal effects of visceral adipose tissue on risk of cancers: a Mendelian randomization study

BACKGROUND

Despite the established association between obesity and cancer risk, it remains unclear whether visceral obesity is causally related to cancer risk and whether it is more pro-oncogenic than total body fat.

METHODS

We conducted two-sample Mendelian randomization (MR) analysis to assess the causal effects of visceral adipose tissue (VAT) on six common cancers. For exposure data, 221 genetic variants associated with the predicted volume of VAT in 325 153 Europeans from UK Biobank were used as instrumental variables. Genetic association data of six common cancers (breast, lung, colorectal, ovarian, pancreatic and prostate cancers) were obtained from large-scale consortia with an average of 19 576 cases and 43 272 controls. We performed univariable MR with five MR methods [inverse-variance weighted (IVW), MR-Egger regression, weighted median, MR-Pleiotropy Residual Sum and Outlier (MR-PRESSO) and Radial MR] and multivariable MR to estimate the effect of VAT independent of body mass index (BMI). Finally, we performed a series of sensitivity analyses as validation of primary MR results.

RESULTS

Two associations survived the false discovery rate correction for multiple testing (q-value < 0.05): in IVW, the odds ratios (95% CIs) per unit increase in genetically determined VAT were 1.65 (1.03 to 2.62) for pancreatic cancer and 1.47 (1.20 to 1.82) for lung squamous-cell carcinoma, respectively, which showed the same directions and overlapped confidence intervals with MR-Egger regression and weighted median results. There were no outlier variants identified by MR-PRESSO and no evidence supporting the presence of heterogeneity and pleiotropy in sensitivity analyses, although with wider confidence intervals that included the null, multivariable MR results for these two cancers showed the same directions and similar effect sizes as in IVW, which were independent of the effect from BMI. There was no evidence for a causal effect of VAT on the risk of other types of cancer.

CONCLUSION

Our findings suggest that lifelong exposure to elevated volumes of VAT might increase the risk of pancreatic cancer and lung squamous-cell carcinoma, highlighting the importance of revealing the underlying mechanisms for intervention targets.

Energy homeostasis genes modify the association between serum concentrations of IGF-1 and IGFBP-3 and breast cancer risk

Breast cancer is a multifactorial disease in which the interplay among multiple risk factors remains unclear. Energy homeostasis genes play an important role in carcinogenesis and their interactions with the serum concentrations of IGF-1 and IGFBP-3 on the risk of breast cancer have not yet been investigated. The aim of this study was to assess the modifying effect of the genetic variation in some energy homeostasis genes on the association of serum concentrations of IGF-1 and IGFBP-3 with breast cancer risk. We analyzed 78 SNPs from 10 energy homeostasis genes in premenopausal women from the 4-Corner’s Breast Cancer Study (61 cases and 155 controls) and the Mexico Breast Cancer Study (204 cases and 282 controls). After data harmonization, 71 SNPs in HWE were included for interaction analysis. Two SNPs in two genes (MBOAT rs13272159 and NPY rs16131) showed an effect modification on the association between IGF-1 serum concentration and breast cancer risk (P_interaction < 0.05, adjusted P_interaction < 0.20). In addition, five SNPs in three genes (ADIPOQ rs182052, rs822391 and rs7649121, CARTPT rs3846659, and LEPR rs12059300) had an effect modification on the association between IGFBP-3 serum concentration and breast cancer risk (P_interaction < 0.05, adjusted P_interaction < 0.20). Our findings showed that variants of energy homeostasis genes modified the association between the IGF-1 or IGFBP-3 serum concentration and breast cancer risk in premenopausal women. These findings contribute to a better understanding of this multifactorial pathology.

Obesity and endocrine therapy resistance in breast cancer: Mechanistic insights and perspectives

The incidence of obesity, a recognized risk factor for various metabolic and chronic diseases, including numerous types of cancers, has risen dramatically over the recent decades worldwide. To date, convincing research in this area has painted a complex picture about the adverse impact of high body adiposity on breast cancer onset and progression. However, an emerging but overlooked issue of clinical significance is the limited efficacy of the conventional endocrine therapies with selective estrogen receptor modulators (SERMs) or degraders (SERDs) and aromatase inhibitors (AIs) in patients affected by breast cancer and obesity. The mechanisms behind the interplay between obesity and endocrine therapy resistance are likely to be multifactorial. Therefore, what have we actually learned during these years and which are the main challenges in the field? In this review, we will critically discuss the epidemiological evidence linking obesity to endocrine therapeutic responses and we will outline the molecular players involved in this harmful connection. Given the escalating global epidemic of obesity, advances in understanding this critical node will offer new precision medicine-based therapeutic interventions and more appropriate dosing schedule for treating patients affected by obesity and with breast tumors resistant to endocrine therapies.

Maximum and Time-Dependent Body Mass Index and Breast Cancer Incidence Among Postmenopausal Women in the Black Women's Health Study

While excess weight is an established risk factor for postmenopausal breast cancer, consideration of maximum body mass index (maxBMI; BMI is calculated as weight (kg)/height (m)2) or BMI at a point in time relevant for breast carcinogenesis may offer new insights. We prospectively evaluated maxBMI and time-dependent BMI in relation to breast cancer incidence among 31,028 postmenopausal women in the Black Women's Health Study. During 1995-2015, a total of 1,384 diagnoses occurred, including 787 estrogen-receptor (ER)-positive (ER+) cases and 310 ER-negative (ER-) cases. BMI was assessed at baseline and 2, 4, 6, and 8 years before diagnosis. Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Compared with women with BMI <25, those with BMI ≥35 had increased risk of ER+ breast cancer but not ER- breast cancer. For BMI assessed 2 years before diagnosis, the HRs for ER+ breast cancer associated with maxBMI ≥35 and time-dependent BMI ≥35 were 1.42 (95% confidence interval (CI): 1.10, 1.84) and 1.63 (95% CI: 1.25, 2.13), respectively. The corresponding HR for time-dependent BMI assessed 6 years before diagnosis was 1.95 (95% CI: 1.45, 2.62). These findings suggest strong associations of BMI with risk of ER+ breast cancer in postmenopausal women, regardless of timing of BMI assessment.

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.

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.

Local Biomarkers Involved in the Interplay between Obesity and Breast Cancer

Simple Summary

Breast cancer is the second most common cancer in women worldwide. The risk of developing breast cancer depends on various mechanisms, such as age, heredity, reproductive factors, physical inactivity, and obesity. Obesity increases the risk of breast cancer and worsens outcomes for breast cancer patients. The rate of obesity is increasing worldwide, stressing the need for awareness of the association between obesity and breast cancer. In this review, we outline the biomarkers—including cellular and soluble factors—in the breast, associated with obesity, that affect the risk of breast cancer and breast cancer prognosis. Through these biomarkers, we aim to better identify patients with obesity with a higher risk of breast cancer and an inferior prognosis.

Abstract

Obesity is associated with an increased risk of breast cancer, which is the most common cancer in women worldwide (excluding non-melanoma skin cancer). Furthermore, breast cancer patients with obesity have an impaired prognosis. Adipose tissue is abundant in the breast. Therefore, breast cancer develops in an adipose-rich environment. During obesity, changes in the local environment in the breast occur which are associated with breast cancer. A shift towards a pro-inflammatory state is seen, resulting in altered levels of cytokines and immune cells. Levels of adipokines, such as leptin, adiponectin, and resistin, are changed. Aromatase activity rises, resulting in higher levels of potent estrogen in the breast. Lastly, remodeling of the extracellular matrix takes place. In this review, we address the current knowledge on the changes in the breast adipose tissue in obesity associated with breast cancer initiation and progression. We aim to identify obesity-associated biomarkers in the breast involved in the interplay between obesity and breast cancer. Hereby, we can improve identification of women with obesity with an increased risk of breast cancer and an impaired prognosis. Studies investigating mammary adipocytes and breast adipose tissue in women with obesity versus women without obesity are, however, sparse and further research is needed.

Association of circulating leptin, adiponectin, and resistin concentrations with long-term breast cancer prognosis in a German patient cohort

Adipokines including leptin, adiponectin and resistin have been linked to risk of obesity-related cancers potentially through low-grade chronic inflammation pathways. We aimed to assess the role of post-diagnosis circulating adipokines on long-term prognosis in a prospective breast cancer cohort. Adipokines were measured in blood collected at baseline shortly after diagnosis (2002-2005) and at follow-up (2009) from 3112 breast cancer patients enrolled in the population-based MARIE study. Half of the patients had measurements at both time-points. All-cause mortality, breast cancer specific mortality and recurrences were ascertained up to June 2015 (11 years median follow-up). Associations with time-varying adipokine concentrations overall and stratified by estrogen and progesterone receptor (ERPR) were evaluated using adjusted proportional hazard regression. At baseline (n = 2700) and follow-up (n = 2027), median concentrations for leptin, adiponectin and resistin were 4.6 and 2.7 ng/ml, 24.4 and 30.0 mg/l, 15.4 and 26.2 ng/ml, respectively. After adjustment, there was no evidence for associations between adipokines and any outcome overall. In ERPR negative tumors, highest vs. lowest quintile of adiponectin was significantly associated with increased breast cancer specific mortality (HR 2.51, 95%CI 1.07-5.92). Overall, post-diagnosis adipokines were not associated with long-term outcomes after breast cancer. In patients with ERPR negative tumors, higher concentrations of adiponectin may be associated with increased breast cancer specific mortality and warrant further investigation.