Concise review: The obesity cancer paradigm: exploration of the interactions and crosstalk with adipose stem cells

Periprostatic Adipose Tissue as a Contributor to Prostate Cancer Pathogenesis: A Narrative Review

Periprostatic adipose tissue (PPAT) contributes to the pathogenesis of prostate cancer. The purpose of this study was to review and summarize the literature on the role of PPAT in prostate cancer pathogenesis. Moreover, we evaluated the clinical implication of PPAT in patients with prostate cancer. We performed a scoping literature review of PubMed from January 2002 to November 2024. Search terms included "periprostatic adipose tissue", "adipokines", and "prostate cancer". Secondary search involved reference lists of eligible articles. The key criterion was to identify studies that included PPAT, adipokines, and their role in prostate cancer biology and clinical features. In total 225 publications were selected for inclusion in this review. The studies contained in publications allowed us to summarize the data on the pathogenesis of PPAT as a contributor to prostate cancer biology and its aggressiveness. The review also presents new research directions for PPAT as a new target for the treatment of prostate cancer. Based on the current review, it can be stated that PPAT plays an important role in prostate cancer pathogenesis. Moreover, PPAT seems to be a promising target point when it comes to finding new therapies in patients with more aggressive and/or advanced stages of prostate cancer.

Crosstalk Between Omental Adipose-Derived Stem Cells and Gastric Cancer Cells Regulates Cancer Stemness and Chemotherapy Resistance

Background: Peritoneal metastasis (PM) remains a major challenge in patients with gastric cancer (GC) and occurs preferentially in adipose-rich organs, such as the omentum. Adipose-derived stem cells (ASCs) may influence cancer behavior. This study aimed to investigate whether ASCs isolated from the omentum can act as progenitors of cancer-associated fibroblasts (CAFs) and analyze their effects on the cancer stem cell (CSC) niche and the treatment resistance of GC cells. Methods: ASCs were isolated from the human omentum and their cellular characteristics were analyzed during co-culturing with GC cells. Results: ASCs express CAF markers and promote desmoplasia in cancer stroma in a mouse xenograft model. When co-cultured with GC cells, ASCs enhanced the sphere-forming efficiency of MKN45 and MKN74 cells. ASCs increased IL-6 secretion and enhanced the expression of Nanog and CD44v6 in GC cells; however, these changes were suppressed by the inhibition of IL-6. Xenograft mouse models co-inoculated with MKN45 cells and ASCs showed enhanced CD44v6 and Nanog expression and markedly reduced apoptosis induced by 5-FU treatment. Conclusion: This study improves our understanding of ASCs' role in PM treatment resistance and has demonstrated the potential for new treatment strategies targeting ASCs.

Overweight and obesity significantly increase colorectal cancer risk: a meta-analysis of 66 studies revealing a 25-57% elevation in risk

The incidence of colorectal cancer (CRC) has been steadily rising, and obesity has been identified as a significant risk factor. Numerous studies suggest a strong correlation between excess body weight and increased risk of CRC, but comprehensive quantification through pooled analysis remains limited. This study aims to systematically review and meta-analyze the existing literature to evaluate the association between obesity and CRC risk, considering variations across sex and study designs. A systematic literature search was conducted in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science to identify randomized controlled trials and human clinical trials from 1992 to 2024. Statistical analysis was performed using the https://metaanalysisonline.com web application using a random effects model to estimate the pooled hazard rates (HR). Forest plots, funnel plots, and Z-score plots were utilized to visualize results. We identified 52 clinical trials and 14 case-control studies, encompassing a total of 83,251,050 and 236,877 subjects, respectively. The pooled analysis indicated that obesity significantly increased the prevalence of CRC (HR = 1.36, 95% CI = 1.24-1.48, p < 0.01). This effect was consistent across sexes, with HRs of 1.57 (95% CI = 1.38-1.78, p = 0.01) for males and 1.25 (95% CI = 1.14-1.38, p < 0.01) for females. Case-control studies specifically showed an effect, but with marginal significance only (HR = 1.27, 95% CI = 0.98-1.65, p = 0.07). The Z-score plot indicated the need for additional analysis in the case-control group. A significant heterogeneity was observed across studies in all four settings. This meta-analysis provides robust evidence that obesity is a significant risk factor for colorectal cancer, with an overall hazard rate indicating a 36% increased risk. The effect is pronounced across both sexes, with males showing a slightly higher risk compared to females. Although case-control studies showed a weaker association, the overall trend supports the link between obesity and CRC. These results underscore the importance of public health interventions aimed at reducing obesity to potentially lower the risk of colorectal cancer.

Adipose Stem Cells and Their Interplay with Cancer Cells and Mitochondrial Reservoir: A New Promising Target

Adipose-derived stem cells (ASCs) significantly influence tumor progression within the tumor microenvironment (TME). This review examines the pro-tumorigenic roles of ASCs, focusing on paracrine signaling, direct cell-cell interactions, and immunomodulation. ASC-mediated mitochondrial transfer through tunneling nanotubes (TNTs) and gap junctions (GJs) plays a significant role in enhancing cancer cell survival and metabolism. Cancer cells with dysfunctional mitochondria acquire mitochondria from ASCs to meet their metabolic needs and thrive in the TME. Targeting mitochondrial transfer, modulating ASC function, and influencing metabolic pathways are potential therapeutic strategies. However, challenges like TME complexity, specificity, safety concerns, and resistance mechanisms must be addressed. Disrupting the ASC-cancer cell-mitochondria axis offers a promising approach to cancer therapy.

Bone health and body composition in prostate cancer: Meet-URO and AIOM consensus about prevention and management strategies

BACKGROUND

Prostate cancer (PCa) treatments are associated with a detrimental impact on bone health (BH) and body composition. However, the evidence on these issues is limited and contradictory. This consensus, based on the Delphi method, provides further guidance on BH management in PCa.

MATERIALS AND METHODS

In May 2023, a survey made up of 37 questions and 74 statements was developed by a group of oncologists and endocrinologists with expertise in PCa and BH. In June 2023, 67 selected Italian experts, belonging to the Italian scientific societies Italian Association of Medical Oncology and Italian Network for Research in Urologic-Oncology (Meet-URO), were invited by e-mail to complete it, rating their strength of agreement with each statement on a 5-point scale. An agreement ≥75% defined the statement as accepted.

RESULTS

In non-metastatic hormone-sensitive PCa, the panel agreed that androgen deprivation therapy (ADT) alone implies sufficient fracture risk to warrant antifracture therapy with bone-targeting agents (BTAs) for cancer treatment-induced bone loss (CTIBL) prevention (79%). Therefore, no consensus was reached (48%) for the treatment with BTAs of patients receiving short-term ADT (<6 months). All patients receiving active treatment for metastatic hormone-sensitive PCa (75%), non-metastatic castration-resistant PCa (89%) and metastatic castration-resistant PCa (mCRPC) without bone metastases (84%) should be treated with BTAs at the doses and schedule for CTIBL prevention. All mCRPC patients with bone metastasis should be treated with BTAs to reduce skeletal-related events (94%). In all settings, the panel analyzed the type and timing of treatments and examinations to carry out for BH monitoring. The panel agreed on the higher risk of sarcopenic obesity of these patients and its correlation with bone fragility.

CONCLUSIONS

This consensus highlights areas lacking major agreement, like non-metastatic hormone-sensitive prostate cancer patients undergoing short-term ADT. Evaluation of these issues in prospective clinical trials and identification of early biomarkers of bone loss are particularly urgent.

Advancements in culture technology of adipose-derived stromal/stem cells: implications for diabetes and its complications

Stem cell-based therapies exhibit considerable promise in the treatment of diabetes and its complications. Extensive research has been dedicated to elucidate the characteristics and potential applications of adipose-derived stromal/stem cells (ASCs). Three-dimensional (3D) culture, characterized by rapid advancements, holds promise for efficacious treatment of diabetes and its complications. Notably, 3D cultured ASCs manifest enhanced cellular properties and functions compared to traditional monolayer-culture. In this review, the factors influencing the biological functions of ASCs during culture are summarized. Additionally, the effects of 3D cultured techniques on cellular properties compared to two-dimensional culture is described. Furthermore, the therapeutic potential of 3D cultured ASCs in diabetes and its complications are discussed to provide insights for future research.

Adipose Tissue in Breast Cancer Microphysiological Models to Capture Human Diversity in Preclinical Models

Female breast cancer accounts for 15.2% of all new cancer cases in the United States, with a continuing increase in incidence despite efforts to discover new targeted therapies. With an approximate failure rate of 85% for therapies in the early phases of clinical trials, there is a need for more translatable, new preclinical in vitro models that include cellular heterogeneity, extracellular matrix, and human-derived biomaterials. Specifically, adipose tissue and its resident cell populations have been identified as necessary attributes for current preclinical models. Adipose-derived stromal/stem cells (ASCs) and mature adipocytes are a normal part of the breast tissue composition and not only contribute to normal breast physiology but also play a significant role in breast cancer pathophysiology. Given the recognized pro-tumorigenic role of adipocytes in tumor progression, there remains a need to enhance the complexity of current models and account for the contribution of the components that exist within the adipose stromal environment to breast tumorigenesis. This review article captures the current landscape of preclinical breast cancer models with a focus on breast cancer microphysiological system (MPS) models and their counterpart patient-derived xenograft (PDX) models to capture patient diversity as they relate to adipose tissue.

Obesity and prostate cancer - microenvironmental roles of adipose tissue

Obesity is known to have important roles in driving prostate cancer aggressiveness and increased mortality. Multiple mechanisms have been postulated for these clinical observations, including effects of diet and lifestyle, systemic changes in energy balance and hormonal regulation and activation of signalling by growth factors and cytokines and other components of the immune system. Over the past decade, research on obesity has shifted towards investigating the role of peri-prostatic white adipose tissue as an important source of locally produced factors that stimulate prostate cancer progression. Cells that comprise white adipose tissue, the adipocytes and their progenitor adipose stromal cells (ASCs), which proliferate to accommodate white adipose tissue expansion in obesity, have been identified as important drivers of obesity-associated cancer progression. Accumulating evidence suggests that adipocytes are a source of lipids that are used by adjacent prostate cancer cells. However, results of preclinical studies indicate that ASCs promote tumour growth by remodelling extracellular matrix and supporting neovascularization, contributing to the recruitment of immunosuppressive cells, and inducing epithelial-mesenchymal transition through paracrine signalling. Because epithelial-mesenchymal transition is associated with cancer chemotherapy resistance and metastasis, ASCs are considered to be potential targets of therapies that could be developed to suppress cancer aggressiveness in patients with obesity.

Pathogenic Role of Adipose Tissue-Derived Mesenchymal Stem Cells in Obesity and Obesity-Related Inflammatory Diseases

Adipose tissue-derived mesenchymal stem cells (ASCs) are adult stem cells, endowed with self-renewal, multipotent capacities, and immunomodulatory properties, as mesenchymal stem cells (MSCs) from other origins. However, in a pathological context, ASCs like MSCs can exhibit pro-inflammatory properties and attract inflammatory immune cells at their neighborhood. Subsequently, this creates an inflammatory microenvironment leading to ASCs' or MSCs' dysfunctions. One such example is given by obesity where adipogenesis is impaired and insulin resistance is initiated. These opposite properties have led to the classification of MSCs into two categories defined as pro-inflammatory ASC1 or anti-inflammatory ASC2, in which plasticity depends on the micro-environmental stimuli. The aim of this review is to (i) highlight the pathogenic role of ASCs during obesity and obesity-related inflammatory diseases, such as rheumatoid arthritis, multiple sclerosis, psoriasis, inflammatory bowel disease, and cancer; and (ii) describe some of the mechanisms leading to ASCs dysfunctions. Thus, the role of soluble factors, adhesion molecules; TLRs, Th17, and Th22 cells; γδ T cells; and immune checkpoint overexpression will be addressed.

Two-sided roles of adipose tissue: Rethinking the obesity paradox in various human diseases from a new perspective

Overweight and obesity, as a result of excess fat accumulation, have become a worldwide public health issue. Recent studies have shown that obesity is closely related to many human diseases, such as cancer, cardiovascular diseases, and type 2 diabetes mellitus, in which adipose tissue plays a dual role. In addition to thermal and mechanical insulation and a critical role in energy storage and heat production, adipose tissue is also a highly plastic endocrine and signaling organ that secretes multiple bioactive molecules for inter-organ crosstalk. The phenotypic and biological changes of adipose tissue under pathological conditions, especially in obesity, increase the challenge of deciphering the positive or negative effects of adipose tissue in disease. Despite numerous studies on obesity and adipose tissue, the ambiguous role of adipose tissue on specific organs or tissues in different diseases is not fully understood, and the definite mechanisms remain obscure. In this review, we first summarize the basic biological characteristics of adipose tissue in the physiological state and the abnormal remodeling of adipose tissue during obesity. We then discuss the complex and disparate effects of obesity on various human diseases, with a particular focus on the dual roles and underlying mechanisms of adipose tissue, a quintessential player in obesity, in this process. More importantly, rethinking the causes of the "obesity paradox" phenomenon in diseases from the perspective of adipose homeostasis and dysfunction provides a novel strategy for disease treatment by intervening in fat function.

Pancreatic cancer cell exosomes induce lipidomics changes in adipocytes

Increasing evidence has demonstrated the important roles of exosomes during pancreatic cancer development. However, the effects of pancreatic cancer exosomes (PC-exos) on adipocytes remain largely unknown. Here, we used mass-spectrometry-based lipidomics to identify lipids that were changed in adipocytes after exposure to PC-exos, and we found that triglyceride (TG) reduction was the most significant, which might be induced by increased lipolysis because the number of large lipid droplets increased while small ones decreased. Additionally, abdominal adipocytes in mice injected with PC-exos had a relatively smaller size. Mechanistically, we found that genes involved in metabolism and inflammation were up-regulated, among which increase of IL-6 was significant, and we then found IL-6 promoted lipolysis. To our knowledge, this is the first study on the lipidomics changes of adipocytes after PC-exos treatment.

Autophagy and the primary cilium in cell metabolism: What’s upstream?

The maintenance of cellular homeostasis in response to extracellular stimuli, i.e., nutrient and hormone signaling, hypoxia, or mechanical forces by autophagy, is vital for the health of various tissues. The primary cilium (PC) is a microtubule-based sensory organelle that regulates the integration of several extracellular stimuli. Over the past decade, an interconnection between autophagy and PC has begun to be revealed. Indeed, the PC regulates autophagy and in turn, a selective form of autophagy called ciliophagy contributes to the regulation of ciliogenesis. Moreover, the PC regulates both mitochondrial biogenesis and lipophagy to produce free fatty acids. These two pathways converge to activate oxidative phosphorylation and produce ATP, which is mandatory for cell metabolism and membrane transport. The autophagy-dependent production of energy is fully efficient when the PC senses shear stress induced by fluid flow. In this review, we discuss the cross-talk between autophagy, the PC and physical forces in the regulation of cell biology and physiology.

Obesity-Related Cross-Talk between Prostate Cancer and Peripheral Fat: Potential Role of Exosomes

The molecular mechanisms of obesity-induced cancer progression have been extensively explored because of the significant increase in obesity and obesity-related diseases worldwide. Studies have shown that obesity is associated with certain features of prostate cancer. In particular, bioactive factors released from periprostatic adipose tissues mediate the bidirectional communication between periprostatic adipose tissue and prostate cancer. Moreover, recent studies have shown that extracellular vesicles have a role in the relationship between tumor peripheral adipose tissue and cancer progression. Therefore, it is necessary to investigate the feedback mechanisms between prostate cancer and periglandular adipose and the role of exosomes as mediators of signal exchange to understand obesity as a risk factor for prostate cancer. This review summarizes the two-way communication between prostate cancer and periglandular adipose and discusses the potential role of exosomes as a cross-talk and the prospect of using adipose tissue as a means to obtain exosomes in vitro. Therefore, this review may provide new directions for the treatment of obesity to suppress prostate cancer.

Adipose-Derived Stromal/Stem Cell Response to Tumors and Wounds: Evaluation of Patient Age

Tumors were characterized as nonhealing wounds by Virchow in 1858 and Dvorak in 1986. Since then, researchers have analyzed tumors from a new perspective. The parallels between tumorigenesis and physiological wound healing can provide a new framework for developing antitumor therapeutics. One commonality between tumors and wounds is the involvement of the stromal environment, particularly adipose stromal/stem cells (ASCs). ASCs exhibit dual functions, in which they stimulate tumor progression and assist in tissue repair and regeneration. Numerous studies have focused on the role of ASCs in cancer and wound healing, but none to date has linked age, cancer, and wound healing. Furthermore, very few studies have focused on the role of donor-specific characteristics of ASCs, such as age and their role in facilitating ASC behavior in cancer and wound healing. This review article is designed to provide important insights into the impact of donor age on ASC tumor and wound response and their role in facilitating ASC behavior in cancer and wound healing.

The effect of obesity on adipose-derived stromal cells and adipose tissue and their impact on cancer

The significant increase in the incidence of obesity represents the next global health crisis. As a result, scientific research has focused on gaining deeper insights into obesity and adipose tissue biology. As a result of the excessive accumulation of adipose tissue, obesity results from hyperplasia and hypertrophy within the adipose tissue. The functional alterations in the adipose tissue are a confounding contributing factor to many diseases, including cancer. The increased incidence and aggressiveness of several cancers, including colorectal, postmenopausal breast, endometrial, prostate, esophageal, hematological, malignant melanoma, and renal carcinomas, result from obesity as a contributing factor. The increased morbidity and mortality of obesity-associated cancers are attributable to increased hormones, adipokines, and cytokines produced by the adipose tissue. The increased adipose tissue levels observed in obese patients result in more adipose stromal/stem cells (ASCs) distributed throughout the body. ASCs have been shown to impact cancer progression in vitro and in preclinical animal models. ASCs influence tumor biology via multiple mechanisms, including the increased recruitment of ASCs to the tumor site and increased production of cytokines and growth factors by ASCs and other cells within the tumor stroma. Emerging evidence indicates that obesity induces alterations in the biological properties of ASCs, subsequently leading to enhanced tumorigenesis and metastasis of cancer cells. As the focus of this review is the interaction and impact of ASCs on cancer, the presentation is limited to preclinical data generated on cancers in which there is a demonstrated role for ASCs, such as postmenopausal breast, colorectal, prostate, ovarian, multiple myeloma, osteosarcoma, cervical, bladder, and gastrointestinal cancers. Our group has investigated the interactions between obesity and breast cancer and the mechanisms that regulate ASCs and adipocytes in these different contexts through interactions between cancer cells, immune cells, and other cell types present in the tumor microenvironment (TME) are discussed. The reciprocal and circular feedback loop between obesity and ASCs and the mechanisms by which ASCs from obese patients alter the biology of cancer cells and enhance tumorigenesis will be discussed. At present, the evidence for ASCs directly influencing human tumor growth is somewhat limited, though recent clinical studies suggest there may be some link.

Adipose Tissue-Derived Mesenchymal Stromal/Stem Cells, Obesity and the Tumor Microenvironment of Breast Cancer

Breast cancer is the most frequently diagnosed cancer and a common cause of cancer-related death in women. It is well recognized that obesity is associated with an enhanced risk of more aggressive breast cancer as well as reduced patient survival. Adipose tissue is the major microenvironment of breast cancer. Obesity changes the composition, structure, and function of adipose tissue, which is associated with inflammation and metabolic dysfunction. Interestingly, adipose tissue is rich in ASCs/MSCs, and obesity alters the properties and functions of these cells. As a key component of the mammary stroma, ASCs play essential roles in the breast cancer microenvironment. The crosstalk between ASCs and breast cancer cells is multilateral and can occur both directly through cell-cell contact and indirectly via the secretome released by ASC/MSC, which is considered to be the main effector of their supportive, angiogenic, and immunomodulatory functions. In this narrative review, we aim to address the impact of obesity on ASCs/MSCs, summarize the current knowledge regarding the potential pathological roles of ASCs/MSCs in the development of breast cancer, discuss related molecular mechanisms, underline the possible clinical significance, and highlight related research perspectives. In particular, we underscore the roles of ASCs/MSCs in breast cancer cell progression, including proliferation and survival, angiogenesis, migration and invasion, the epithelial-mesenchymal transition, cancer stem cell development, immune evasion, therapy resistance, and the potential impact of breast cancer cells on ASCS/MSCs by educating them to become cancer-associated fibroblasts. We conclude that ASCs/MSCs, especially obese ASCs/MSCs, may be key players in the breast cancer microenvironment. Targeting these cells may provide a new path of effective breast cancer treatment.

Adipogenic progenitors in different organs: Pathophysiological implications

In physiological conditions, the adipose organ resides in well-defined areas, where it acts providing an energy supply and as an endocrine organ involved in the control of whole-body energy metabolism. Adipose tissue adipokines connect the body's nutritional status to the regulation of energy balance. When it surrounds organs, it provides also for mechanical protection. Adipose tissue has a complex and heterogenous cellular composition that includes adipocytes, adipose tissue-derived stromal and stem cells (ASCs) which are mesenchymal stromal cells, and endothelial and immune cells, which signal to each other and to other tissues to maintain homeostasis. In obesity and in other nutrition related diseases, as well as in age-related diseases, biological and functional changes of adipose tissue give rise to several complications. Obesity triggers alterations of ASCs, impairing adipose tissue remodeling and adipose tissue function, which induces low-grade systemic inflammation, progressive insulin resistance and other metabolic disorders. Adipose tissue grows by hyperplasia recruiting new ASCs and by hypertrophy, up to its expandability limit. To overcome this limitation and to store the excess of nutrients, adipose tissue develops ectopically, involving organs such as muscle, bone marrow and the heart. The origin of ectopic adipose organ is not clearly elucidated, and a possible explanation lies in the stimulation of the adipogenic differentiation of mesenchymal precursor cells which normally differentiate toward a lineage specific for the organ in which they reside. The chronic exposition of these newly-formed adipose depots to the pathological environment, will confer to them all the phenotypic characteristics of a dysfunctional adipose tissue, perpetuating the organ alterations. Visceral fat, but also ectopic fat, either in the liver, muscle or heart, can increase the risk of developing insulin resistance, type 2 diabetes, and cardiovascular diseases. Being able to prevent and to target dysfunctional adipose tissue will avoid the progression towards the complications of obesity and other nutrition-related diseases. The aim of this review is to summarize some of the knowledge regarding the presence of adipose tissue in particular tissues (where it is not usually present), describing the composition of its adipogenic precursors, and the interactions responsible for the development of organ pathologies.

Adipose Stem Cell-Based Treatments for Wound Healing

Wound healing is one of the most complex physiological regulation mechanisms of the human body. Stem cell technology has had a significant impact on regenerative medicine. Adipose stem cells (ASCs) have many advantages, including their ease of harvesting and high yield, rich content of cell components and cytokines, and strong practicability. They have rapidly become a favored tool in regenerative medicine. Here, we summarize the mechanism and clinical therapeutic potential of ASCs in wound repair.

Human placental mesenchymal stromal cells are ciliated and their ciliation is compromised in preeclampsia

BACKGROUND

The development of the human placenta is tightly coordinated by a multitude of placental cell types, including human chorionic villi mesenchymal stromal cells (hCV-MSCs). Defective hCV-MSCs have been reported in preeclampsia (PE), a gestational hypertensive disease characterized by maternal endothelial dysfunction and systemic inflammation. Our goal was to determine whether hCV-MSCs are ciliated and whether altered ciliation is responsible for defective hCV-MSCs in preeclamptic placentas, as the primary cilium is a hub for signal transduction, which is important for various cellular activities.

METHODS

In the present work, we collected placental tissues from different gestational stages and we isolated hCV-MSCs from 1st trimester, term control, and preeclamptic placentas. We studied their ciliation, functionality, and impact on trophoblastic cell lines and organoids formed from human trophoblast stem cells (hTSCs) and from the trophoblastic cell line JEG-3 with various cellular and molecular methods, including immunofluorescence staining, gene analysis, spheroid/organoid formation, motility, and cellular network formation assay. The statistical evaluation was performed using a Student's t test (two-tailed and paired or homoscedastic) or an unpaired Mann-Whitney U test (two-tailed).

RESULTS

The results show that primary cilia appeared abundantly in normal hCV-MSCs, especially in the early development of the placenta. Compared to control hCV-MSCs, the primary cilia were truncated, and there were fewer ciliated hCV-MSCs derived from preeclamptic placentas with impaired hedgehog signaling. Primary cilia are necessary for hCV-MSCs' proper signal transduction, motility, homing, and differentiation, which are impaired in preeclamptic hCV-MSCs. Moreover, hCV-MSCs derived from preeclamptic placentas are significantly less capable of promoting growth and differentiation of placental organoids, as well as cellular network formation.

CONCLUSIONS

These data suggest that the primary cilium is required for the functionality of hCV-MSCs and primary cilia are impaired in hCV-MSCs from preeclamptic placentas.

Use of Adipose Stem Cells Against Hypertrophic Scarring or Keloid

Hypertrophic scars or keloid form as part of the wound healing reaction process, and its formation mechanism is complex and diverse, involving multi-stage synergistic action of multiple cells and factors. Adipose stem cells (ASCs) have become an emerging approach for the treatment of many diseases, including hypertrophic scarring or keloid, owing to their various advantages and potential. Herein, we analyzed the molecular mechanism of hypertrophic scar or keloid formation and explored the role and prospects of stem cell therapy, in the treatment of this condition.

Mesenchymal Stem Cells in Adipose Tissue and Extracellular Vesicles in Ovarian Cancer Patients: A Bridge toward Metastatic Diffusion or a New Therapeutic Opportunity?

Ovarian cancer is one of the deadliest malignancies among women. Approximately 75% of the patients with ovarian cancer are diagnosed with advanced disease that already has metastasis, particularly to the omentum. The omentum constitutes the ideal soil for ovarian cancer metastasis due to a complex intraperitoneal milieu that favors and supports the whole metastatic process. Adipose-derived stem/stromal cells (ADSCs) are part of this microenvironment and foster tumor progression via sustained paracrine secretion, including extracellular vesicles (EVs). Nonetheless, the preferential relationship between ADSCs, ADSC-derived EVs, and ovarian cancer cells could be exploited to use ADSCs and EVs as a vehicle for anti-cancer therapies. This review will analyze the strict relations between tumor progression, metastatic disease, and adipose tissue with its staminal components. In addition, we will describe the crosstalk and biologic relationship between ADSCs and tumor cells, the role of EVs in intercellular communication, the establishment of drug resistance, metastatic capacity, and ovarian cancer progression. We will analyze the new therapeutic opportunities in treating ovarian cancer offered by ADSCs and EVs as a vehicle for therapeutic molecules to target precisely tumor cells and limit the systemic adverse effects. Finally, we will discuss the limitations of these therapeutic approaches.

Uterine carcinosarcoma: An overview

Uterine carcinosarcoma (UCS), also known as malignant mixed Müllerian tumor, is a rare gynecological malignancy characterized by poor prognosis. This "biphasic" neoplasm presents an admixture of epithelial and mesenchymal/sarcomatoid tumor cells which partially share their molecular signature and exhibit a typical epithelial-to-mesenchymal transition gene expression profile. Due to the rarity of this cancer, at present there is a scarcity of specific treatment guidelines. Surgical resection remains the best curative option for localized disease, whereas the addition of peri-operative radiotherapy, chemotherapy and chemoradiation has been shown to further improve disease outcomes. In the metastatic setting, palliative chemotherapy is currently the treatment of choice, although no consensus exists about the best regimen to be delivered. Besides standard treatment options for the advanced disease, mechanistic insights into UCS pathogenesis and identification of its histopathological and molecular features boosted the development of novel, and potentially more effective, therapeutic agents, that will be here discussed.

Mechanistic Insights into the Link between Obesity and Prostate Cancer

Obesity is a pandemic of increasing worldwide prevalence. There is evidence of an association between obesity and the risk of prostate cancer from observational studies, and different biologic mechanisms have been proposed. The chronic low-level inflammation within the adipose tissue in obesity results in oxidative stress, activation of inflammatory cytokines, deregulation of adipokines signaling, and increased circulating levels of insulin and insulin-like growth factors (IGF). These mechanisms may be involved in epithelial to mesenchymal transformation into a malignant phenotype that promotes invasiveness, aggressiveness, and metastatic potential of prostate cancer. A thorough understanding of these mechanisms may be valuable in the development of effective prostate cancer prevention strategies and treatments. This review provides an overview of these mechanisms.

The Influence of Biologically Active Substances Secreted by the Adipose Tissue on Endometrial Cancer

Endometrial cancer is one of the most frequently diagnosed gynecological neoplasms in developed countries and its incidence is rising. Usually, it is diagnosed in the early stages of the disease and has a good prognosis; however, in later stages, the rate of recurrence reaches up to 60%. The discrepancy in relapse rates is due to the heterogeneity of the group related to the presence of prognostic factors affecting survival parameters. Increased body weight, diabetes, metabolic disturbances and estrogen imbalance are important factors for the pathogenesis of endometrial cancer. Even though prognostic factors such as histopathological grade, clinical stage, histological type and the presence of estrogen and progesterone receptors are well known in endometrial cancer, the search for novel prognostic biomarkers continues. Adipose tissue is an endocrine organ involved in metabolism, immune response and the production of biologically active substances participating in cell growth and differentiation, angiogenesis, apoptosis and carcinogenesis. In this manuscript, we review the impact of factors secreted by the adipose tissue involved in the regulation of glucose and lipid metabolism (leptin, adiponectin, omentin, vaspin, galectins) and factors responsible for homeostasis maintenance, inflammatory processes, angiogenesis and oxidative stress (IL-1β, 6, 8, TNFα, Vascular endothelial growth factor (VEGF), Fibroblast growth factors (FGFs)) in the diagnosis and prognosis of endometrial cancer.

Adipose Tissue-Derived Stem Cells: Immunomodulatory Effects and Therapeutic Potential

Adipose-derived stem cells (ASCs) can self-renew and differentiate along multiple cell lineages. ASCs are also potently anti-inflammatory due to their inherent ability to regulate the immune system by secreting anti-inflammatory cytokines and growth factors that play a crucial role in the pathology of many diseases, including multiple sclerosis, diabetes mellitus, Crohn's, SLE, and graft-versus-host disease. The immunomodulatory effects and mechanisms of action of ASCs on pathological conditions are reviewed here.

Discovery of DS68702229 as a Potent, Orally Available NAMPT (Nicotinamide Phosphoribosyltransferase) Activator

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the rate-limiting step of the nicotinamide adenine dinucleotide (NAD+) salvage pathway. Because NAD+ plays a pivotal role in energy metabolism and boosting NAD+ has positive effects on metabolic regulation, activation of NAMPT is an attractive therapeutic approach for the treatment of various diseases, including type 2 diabetes and obesity. Herein we report the discovery of 1-(2-phenyl-1,3-benzoxazol-6-yl)-3-(pyridin-4-ylmethyl)urea 12c (DS68702229), which was identified as a potent NAMPT activator. Compound 12c activated NAMPT, increased cellular NAD+ levels, and exhibited an excellent pharmacokinetic profile in mice after oral administration. Oral administration of compound 12c to high-fat diet-induced obese mice decreased body weight. These observations indicate that compound 12c is a promising anti-obesity drug candidate.

Endocrine-Disrupting Chemicals' (EDCs) Effects on Tumour Microenvironment and Cancer Progression: Emerging Contribution of RACK1

Endocrine disruptors (EDCs) can display estrogenic and androgenic effects, and their exposure has been linked to increased cancer risk. EDCs have been shown to directly affect cancer cell regulation and progression, but their influence on tumour microenvironment is still not completely elucidated. In this context, the signalling hub protein RACK1 (Receptor for Activated C Kinase 1) could represent a nexus between cancer and the immune system due to its roles in cancer progression and innate immune activation. Since RACK1 is a relevant EDCs target that responds to steroid-active compounds, it could be considered a molecular bridge between the endocrine-regulated tumour microenvironment and the innate immune system. We provide an analysis of immunomodulatory and cancer-promoting effects of different EDCs in shaping tumour microenvironment, with a final focus on the scaffold protein RACK1 as a pivotal molecular player due to its dual role in immune and cancer contexts.

Fat-On-A-Chip Models for Research and Discovery in Obesity and Its Metabolic Comorbidities

The obesity epidemic and its associated comorbidities present a looming challenge to health care delivery throughout the world. Obesity is characterized as a sterile inflammatory process within adipose tissues leading to dysregulated secretion of bioactive adipokines such as adiponectin and leptin, as well as systemic metabolic dysfunction. The majority of current obesity research has focused primarily on preclinical animal models in vivo and two-dimensional cell culture models in vitro. Neither of these generalized approaches is optimal due to interspecies variability, insufficient accuracy with respect to predicting human outcomes, and failure to recapitulate the three-dimensional (3D) microenvironment. Consequently, there is a growing demand and need for more sophisticated microphysiological systems to reproduce more physiologically accurate human white and brown/beige adipose depots. To address this research need, human and murine cell lines and primary cultures are being combined with bioscaffolds to create functional 3D environments that are suitable for metabolically active adipose organoids in both static and perfusion bioreactor cultures. The development of these technologies will have considerable impact on the future pace of discovery for novel small molecules and biologics designed to prevent and treat metabolic syndrome and obesity in humans. Furthermore, when these adipose tissue models are integrated with other organ systems they will have applicability to obesity-related disorders such as diabetes, nonalcoholic fatty liver disease, and osteoarthritis. Impact statement The current review article summarizes the advances made within the organ-onchip field, as it pertains to adipose tissue models of obesity and obesity-related syndromes, such as diabetes, non-alcoholic fatty liver disease, and osteoarthritis. As humanized 3D adipose-derived constructs become more accessible to the research community, it is anticipated that they will accelerate and enhance the drug discovery pipeline for obesity, diabetes, and metabolic diseases by reducing the preclinical evaluation process and improving predictive accuracy. Such developments, applications, and usages of existing technologies can change the paradigm of personalized medicine and create substantial progress in our approach to modern medicine.

Roles of Adipokines in Digestive Diseases: Markers of Inflammation, Metabolic Alteration and Disease Progression

Adipose tissue is a highly dynamic endocrine tissue and constitutes a central node in the interorgan crosstalk network through adipokines, which cause pleiotropic effects, including the modulation of angiogenesis, metabolism, and inflammation. Specifically, digestive cancers grow anatomically near adipose tissue. During their interaction with cancer cells, adipocytes are reprogrammed into cancer-associated adipocytes and secrete adipokines to affect tumor cells. Moreover, the liver is the central metabolic hub. Adipose tissue and the liver cooperatively regulate whole-body energy homeostasis via adipokines. Obesity, the excessive accumulation of adipose tissue due to hyperplasia and hypertrophy, is currently considered a global epidemic and is related to low-grade systemic inflammation characterized by altered adipokine regulation. Obesity-related digestive diseases, including gastroesophageal reflux disease, Barrett's esophagus, esophageal cancer, colon polyps and cancer, non-alcoholic fatty liver disease, viral hepatitis-related diseases, cholelithiasis, gallbladder cancer, cholangiocarcinoma, pancreatic cancer, and diabetes, might cause specific alterations in adipokine profiles. These patterns and associated bases potentially contribute to the identification of prognostic biomarkers and therapeutic approaches for the associated digestive diseases. This review highlights important findings about altered adipokine profiles relevant to digestive diseases, including hepatic, pancreatic, gastrointestinal, and biliary tract diseases, with a perspective on clinical implications and mechanistic explorations.

Is There A Causal Relationship between Childhood Obesity and Acute Lymphoblastic Leukemia? A Review

Childhood obesity is a growing epidemic with numerous global health implications. Over the past few years, novel insights have emerged about the contribution of adult obesity to cancer risk, but the evidence base is far more limited in children. While pediatric patients with acute lymphoblastic leukemia (ALL) are at risk of obesity, it is unclear if there are potential causal mechanisms by which obesity leads to ALL development. This review explores the endocrine, metabolic and immune dysregulation triggered by obesity and its potential role in pediatric ALL's genesis. We describe possible mechanisms, including adipose tissue attraction and protection of lymphoblasts, and their impact on ALL chemotherapies' pharmacokinetics. We also explore the potential contribution of cytokines, growth factors, natural killer cells and adipose stem cells to ALL initiation and propagation. While there are no current definite causal links between obesity and ALL, critical questions persist as to whether the adipose tissue microenvironment and endocrine actions can play a causal role in childhood ALL, and there is a need for more research to address these questions.

Adipose Tissue Properties in Tumor-Bearing Breasts

The tissue stroma plays a major role in tumors' natural history. Most programs for tumor progression are not activated as cell-autonomous processes but under the conditions of cross-talks between tumor and stroma. Adipose tissue is a major component of breast stroma. This study compares adipose tissues in tumor-bearing breasts to those in tumor-free breasts with the intention of defining a signature that could translate into markers of cancer risk. In tumor-bearing breasts, we sampled adipose tissues adjacent to, or distant from the tumor. Parameters studied included: adipocytes size and density, immune cell infiltration, vascularization, secretome and gene expression. Adipose tissues from tumor-bearing breasts, whether adjacent to or distant from the tumor, do not differ from each other by any of these parameters. By contrast, adipose tissues from tumor-bearing breasts have the capacity to secrete twice as much interleukin 8 (IL-8) than those from tumor-free breasts and differentially express a set of 137 genes of which a significant fraction belongs to inflammation, integrin and wnt signaling pathways. These observations show that adipose tissues from tumor-bearing breasts have a distinct physiological status from those from tumor-free breasts. We propose that this constitutive status contributes as a non-cell autonomous process to determine permissiveness for tumor growth.

Evaluation of intercellular communication between breast cancer cells and adipose-derived stem cells via passive diffusion in a two-layer microfluidic device

Breast cancer tumorigenesis and response to therapy is regulated by cancer cell interactions with the tumor microenvironment (TME). Breast cancer signaling to the surrounding TME results in a heterogeneous and diverse tumor microenvironment, which includes the production of cancer-associated fibroblasts, macrophages, adipocytes, and stem cells. The secretory profile of these cancer-associated cell types results in elevated chemokines and growth factors that promote cell survival and proliferation within the tumor. Current co-culture approaches mostly rely on transwell chambers to study intercellular signaling between adipose-derived stem cells (ASCs) and cancer cells; however, these methods are limited to endpoint measurements and lack dynamic control. In this study, a 4-channel, "flow-free" microfluidic device was developed to co-culture triple-negative MDA-MB-231 breast cancer cells and ASCs to study intercellular communication between two distinct cell types found in the TME. The device consists of two layers: a top PDMS layer with four imprinted channels coupled with a bottom agarose slab enclosed in a Plexiglas chamber. For dynamic co-culture, the device geometry contained two centered, flow-free channels, which were supplied with media from two outer flow channels via orthogonal diffusion through the agarose. Continuous fresh media was provided to the cell culture channel via passive diffusion without creating any shearing effect on the cells. The device geometry also allowed for the passive diffusion of cytokines and growth factors between the two cell types cultured in parallel channels to initiate cell-to-cell crosstalk. The device was used to show that MDA-MB-231 cells co-cultured with ASCs exhibited enhanced growth, a more aggressive morphology, and polarization toward the ASCs. The MDA-MB-231 cells were found to exhibit a greater degree of resistance to the drug paclitaxel when co-cultured with ASCs when compared to single culture studies. This microfluidic device is an ideal platform to study intercellular communication for many types of cells during co-culture experiments and allows for new investigations into stromal cell-mediated drug resistance in the tumor microenvironment.

Adipocytokines and their relationship to endometrial cancer risk: A systematic review and meta-analysis

OBJECTIVE

To investigate the association between circulating levels of adipocytokines (adiponectin, leptin, tumour necrosis factor alpha (TNFα), interleukin 6 (IL-6)) and growth factors (insulin-like growth factor I (IGF-I) and II (IGF-II)), and the risk of endometrial cancer.

METHODS

Cochrane, CINAHL, Embase, Medline and Web of Science were searched for English-language manuscripts published between January 2000 and August 2018 using the following string of words: cancer and endometrial and (obesity or BMI) and (adiponectin or TNF* or IGF-I or IGF-II or IL-6 or leptin).

RESULTS

Twenty articles were included in this meta-analysis, which corresponded to 18 studies involving 2921 endometrial carcinoma cases and 5302 controls. Fourteen articles reported circulating levels for adiponectin, seven for leptin, three for TNFα, three for IL-6 and one for IGF-I. No article reported values for IGF-II. Patients with circulating adiponectin levels in the highest tertile had decreased endometrial cancer risk compared to women with levels in the lowest tertile, (summary of odds ratio (SOR) 0.51, 95% confidence interval (CI): 0.38-0.69, p < 0.00001). Women with circulating leptin concentrations in the highest tertile had increased endometrial cancer risk compared to women with concentrations in the lowest tertile (SOR 2.19, 95% CI: 1.45-3.30, p = 0.0002). There was no difference in cancer risk between participants with the highest TNFα and IL-6 levels compared to the lowest levels (SOR 1.27, 95% CI: 0.88-1.83, p = 0.20 and SOR 1.20, 95% CI: 0.89-1.63, p = 0.23, respectively).

CONCLUSIONS

Endometrial cancer risk is inversely affected by adiponectin and leptin levels. There appears to be no relationship between TNFα and IL-6 and the overall risk of endometrial cancer.

Life style factors, tumor cell plasticity and cancer stem cells

Cancers are heterogeneous tissues and a layer of heterogeneity is determined by the presence of cells showing stemness traits, known as cancer stem cells (CSCs). Evidence indicates that CSCs are important players in tumor development, progression and relapse. Oncogenic transformation of normal stem cells can give rise to CSCs, but CSCs can also originate from de-differentiation of bulk tumor cells. Thus, factors promoting the increase of normal stem cell pools or stimulating the acquisition of stemness features by tumor cells can have serious consequences on cancer origin and progression. In this review, we will first give an overview of the CSC model of cancer development and we will then discuss the role of life style factors, such as high caloric diet, alcohol drinking and smoking, on the widening of stem cell pools and the induction of CSC features in tumors. Finally, we will discuss some healthy life style factors that can help to prevent cancer.

Adipose stem cells from patients with Crohn's disease show a distinctive DNA methylation pattern

Background

Crohn’s disease (CD) is characterized by persistent inflammation and ulceration of the small or large bowel, and expansion of mesenteric adipose tissue, termed creeping fat (CF). We previously demonstrated that human adipose-derived stem cells (hASCs) from CF of patients with CD exhibit dysfunctional phenotypes, including a pro-inflammatory profile, high phagocytic capacity, and weak immunosuppressive properties. Importantly, these phenotypes persist in patients in remission and are found in all adipose depots explored including subcutaneous fat. We hypothesized that changes in hASCs are a consequence of epigenetic modifications.

Methods

We applied epigenome-wide profiling with a methylation array (Illumina EPIC/850k array) and gene expression analysis to explore the impact of CD on the methylation signature of hASCs isolated from the subcutaneous fat of patients with CD and healthy controls (n = 7 and 5, respectively; cohort I). Differentially methylated positions (p value cutoff < 1 × 10⁻⁴ and ten or more DMPs per gene) and regions (inclusion threshold 0.2, p value cutoff < 1 × 10⁻² and more than 2 DMRs per gene) were identified using dmpfinder and Bumphunter (minfi), respectively. Changes in the expression of differentially methylated genes in hASCs were validated in a second cohort (n = 10/10 inactive and active CD and 10 controls; including patients from cohort I) and also in peripheral blood mononuclear cells (PBMCs) of patients with active/inactive CD and of healthy controls (cohort III; n = 30 independent subjects).

Results

We found a distinct DNA methylation landscape in hASCs from patients with CD, leading to changes in the expression of differentially methylated genes involved in immune response, metabolic, cell differentiation, and development processes. Notably, the expression of several of these genes in hASCs and PBMCs such as tumor necrosis factor alpha (TNFA) and PR domain zinc finger protein 16 (PRDM16) were not restored to normal (healthy) levels after disease remission.

Conclusions

hASCs of patients with CD exhibit a unique DNA methylation and gene expression profile, but the expression of several genes are only partially restored in patients with inactive CD, both in hASCs and PBMCs. Understanding how CD shapes the functionality of hASCs is critical for investigating the complex pathophysiology of this disease, as well as for the success of cell-based therapies.

Graphical abstract

Human adipose-stem cells isolated from subcutaneous fat of patients with Crohn’s disease exhibit an altered DNA methylation pattern and gene expression profile compared with those isolated from healthy individuals, with immune system, cell differentiation, metabolic and development processes identified as the main pathways affected. Interestingly, the gene expression of several genes involved in these pathways is only partially restored to control levels in patients with inactive Crohn’s disease, both in human adipose-stem cells and peripheral blood mononuclear cells. Understanding how Crohn’s disease shapes the functionality of human adipose-stem cells is critical for investigating the complex pathophysiology of this disease, as well as for the success of cell-based therapies.

Measures of body fatness and height in early and mid-to-late adulthood and prostate cancer: risk and mortality in The Pooling Project of Prospective Studies of Diet and Cancer

BACKGROUND

Advanced prostate cancer etiology is poorly understood. Few studies have examined associations of anthropometric factors (e.g. early adulthood obesity) with advanced prostate cancer risk.

PATIENTS AND METHODS

We carried out pooled analyses to examine associations between body fatness, height, and prostate cancer risk. Among 830 772 men, 51 734 incident prostate cancer cases were identified, including 4762 advanced (T4/N1/M1 or prostate cancer deaths) cases, 2915 advanced restricted (same as advanced, but excluding localized cancers that resulted in death) cases, 9489 high-grade cases, and 3027 prostate cancer deaths. Cox proportional hazards models were used to calculate study-specific hazard ratios (HR) and 95% confidence intervals (CI); results were pooled using random effects models.

RESULTS

No statistically significant associations were observed for body mass index (BMI) in early adulthood for advanced, advanced restricted, and high-grade prostate cancer, and prostate cancer mortality. Positive associations were shown for BMI at baseline with advanced prostate cancer (HR = 1.30, 95% CI = 0.95-1.78) and prostate cancer mortality (HR = 1.52, 95% CI = 1.12-2.07) comparing BMI ≥35.0 kg/m2 with 21-22.9 kg/m2. When considering early adulthood and baseline BMI together, a 27% higher prostate cancer mortality risk (95% CI = 9% to 49%) was observed for men with BMI <25.0 kg/m2 in early adulthood and BMI ≥30.0 kg/m2 at baseline compared with BMI <25.0 kg/m2 in early adulthood and BMI <30.0 kg/m2 at baseline. Baseline waist circumference, comparing ≥110 cm with <90 cm, and waist-to-hip ratio, comparing ≥1.00 with <0.90, were associated with significant 14%-16% increases in high-grade prostate cancer risk and suggestive or significant 20%-39% increases in prostate cancer mortality risk. Height was associated with suggestive or significant 33%-56% risks of advanced or advanced restricted prostate cancer and prostate cancer mortality, comparing ≥1.90 m with <1.65 m.

CONCLUSION

Our findings suggest that height and total and central adiposity in mid-to-later adulthood, but not early adulthood adiposity, are associated with risk of advanced forms of prostate cancer. Thus, maintenance of healthy weight may help prevent advanced prostate cancer.

Subcutaneous and Visceral Adipose-Derived Mesenchymal Stem Cells: Commonality and Diversity

Adipose-derived mesenchymal stem cells (ASCs) are considered to be a useful tool for regenerative medicine, owing to their capabilities in differentiation, self-renewal, and immunomodulation. These cells have become a focus in the clinical setting due to their abundance and easy isolation. However, ASCs from different depots are not well characterized. Here, we analyzed the functional similarities and differences of subcutaneous and visceral ASCs. Subcutaneous ASCs have an extraordinarily directed mode of motility and a highly dynamic focal adhesion turnover, even though they share similar surface markers, whereas visceral ASCs move in an undirected random pattern with more stable focal adhesions. Visceral ASCs have a higher potential to differentiate into adipogenic and osteogenic cells when compared to subcutaneous ASCs. In line with these observations, visceral ASCs demonstrate a more active sonic hedgehog pathway that is linked to a high expression of cilia/differentiation related genes. Moreover, visceral ASCs secrete higher levels of inflammatory cytokines interleukin-6, interleukin-8, and tumor necrosis factor α relative to subcutaneous ASCs. These findings highlight, that both ASC subpopulations share multiple cellular features, but significantly differ in their functions. The functional diversity of ASCs depends on their origin, cellular context and surrounding microenvironment within adipose tissues. The data provide important insight into the biology of ASCs, which might be useful in choosing the adequate ASC subpopulation for regenerative therapies.

Leptin produced by obesity-altered adipose stem cells promotes metastasis but not tumorigenesis of triple-negative breast cancer in orthotopic xenograft and patient-derived xenograft models

Background

Breast cancer is the second leading cause of cancer deaths in the USA. Triple-negative breast cancer (TNBC) is a clinically aggressive subtype of breast cancer with high rates of metastasis, tumor recurrence, and resistance to therapeutics. Obesity, defined by a high body mass index (BMI), is an established risk factor for breast cancer. Women with a high BMI have increased incidence and mortality of breast cancer; however, the mechanisms(s) by which obesity promotes tumor progression are not well understood.

Methods

In this study, obesity-altered adipose stem cells (obASCs) were used to evaluate obesity-mediated effects of TNBC. Both in vitro and in vivo analyses of TNBC cell lines were co-cultured with six pooled donors of obASCs (BMI > 30) or ASCs isolated from lean women (lnASCs) (BMI < 25).

Results

We found that obASCs promote a pro-metastatic phenotype by upregulating genes associated with epithelial-to-mesenchymal transition and promoting migration in vitro. We confirmed our findings using a TNBC patient-derived xenograft (PDX) model. PDX tumors grown in the presence of obASCS in SCID/beige mice had increased circulating HLA1⁺ human cells as well as increased numbers of CD44⁺CD24⁻ cancer stem cells in the peripheral blood. Exposure of the TNBC PDX to obASCs also increased the formation of metastases. The knockdown of leptin expression in obASCs suppressed the pro-metastatic effects of obASCs.

Conclusions

Leptin signaling is a potential mechanism through which obASCs promote metastasis of TNBC in both in vitro and in vivo analyses.

Electronic supplementary material

The online version of this article (10.1186/s13058-019-1153-9) contains supplementary material, which is available to authorized users.

Targeting Endometrial Cancer Stem Cell Activity with Metformin Is Inhibited by Patient-Derived Adipocyte-Secreted Factors

Advanced endometrial cancer continues to have a poor prognosis, due to limited treatment options, which may be further adversely impacted by obesity. Endometrial cancer stem cells have been reported to drive metastasis, chemotherapy resistance and disease relapse, but have yet to be fully characterised and no specific targeted therapies have been identified. Here, we describe the phenotype and genotype of aldehyde dehydrogenase high (ALDH^high) and CD133^+ve endometrial cancer stem cells and how adipocyte secreted mediators block the inhibitory effect of metformin on endometrial cancer stem cell activity. Ishikawa and Hec-1a cell lines were used to characterise ALDH^high and CD133^+ve endometrial cancer cells using flow cytometry, functional sphere assays and quantitative-Polymerase Chain Reaction. The comparative effect of metformin on endometrial cancer stem cell activity and bulk tumour cell proliferation was determined using an Aldefluor and cytotoxicity assay. The impact of adipocyte secreted mediators on metformin response was established using patient-derived conditioned media. ALDH^high cells demonstrated greater endometrial cancer stem cell activity than CD133^+ve cells and had increased expression of stem cell and epithelial-mesenchymal transition genes. Treatment with 0.5-1 mM metformin reduced the proportion and activity of both endometrial cancer stem cell populations (p ≤ 0.05), without affecting cell viability. This effect was, however, inhibited by exposure to patient-derived adipocyte conditioned media. These results indicate a selective and specific effect of metformin on endometrial cancer stem cell activity, which is blocked by adipocyte secreted mediators. Future studies of metformin as an adjuvant therapy in endometrial cancer should be adequately powered to investigate the influence of body mass on treatment response.

Human Periprostatic Adipose Tissue: Secretome from Patients With Prostate Cancer or Benign Prostate Hyperplasia

BACKGROUND/AIM

Periprostatic adipose tissue (PPAT) directs tumour behaviour. Microenvironment secretome provides information related to its biology. This study was performed to identify secreted proteins by PPAT, from both prostate cancer and benign prostate hyperplasia (BPH) patients.

PATIENTS AND METHODS

Liquid chromatography-mass spectrometry-based proteomic analysis was performed in PPAT-conditioned media (CM) from patients with prostate cancer (CMs-T) (stage T3: CM-T3, stage T2: CM-T2) or benign disease (CM-BPH).

RESULTS

The highest number and diversity of proteins was identified in CM-T3. Locomotion was the biological process mainly associated to CMs-T and reproduction to CM-T3. Immune responses were enriched in CMs-T. Extracellular matrix and structural proteins were associated to CMs-T. CM-T3 was enriched in proteins with catalytic activity and CM-T2 in proteins with defense/immunity activity. Metabolism and energy pathways were enriched in CM-T3 and those with immune system functions in CMs-T. Transport proteins were enriched in CM-T2 and CM-BPH.

CONCLUSION

Proteins and pathways reported in this study could be useful to distinguish stages of disease and may become targets for novel therapies.

Exosomes secreted by mesenchymal stromal/stem cell-derived adipocytes promote breast cancer cell growth via activation of Hippo signaling pathway

Objective

Although adipocytes are the most abundant stromal cell component in breast cancer tissues, their interaction with breast cancer cells has been less investigated compared to cancer-associated fibroblasts or macrophages. Exosomes are a novel way of cell-cell communication and have been demonstrated to play an important role in various biological processes. However, to our knowledge, only a few studies have reported the effects of adipocyte exosomes on tumor development. Here, utilizing exosomes isolated from in vitro mesenchymal stromal/stem cell (MSC)-differentiated adipocytes, we systematically investigated this issue in a breast cancer model.

Material and methods

Exosomes were isolated from MSC-differentiated adipocytes and added to breast cancer cells MCF7. Cell proliferation was detected by MTS, and migration was analyzed by wound healing and transwell assay. An in vivo mouse xenograft model was used to evaluate MSC-differentiated adipocyte exosomes’ contribution to tumor growth. Signaling pathway activation was evaluated by western blot and immunofluorescence staining.

Results

We found MSC-differentiated adipocyte-derived exosomes are actively incorporated by breast cancer cell MCF7 and subsequently promote MCF7 proliferation and migration as well as protect MCF7 from serum derivation or chemotherapeutic drug-induced apoptosis in vitro. In the in vivo mouse xenograft model, depletion of exosomes reduces tumor-promoting effects of adipocytes. Transcriptomic analysis of MSC-differentiated adipocyte exosome-treated MCF7 identified several activated signaling pathways, among which we confirm the Hippo signaling pathway and found a blockade of this pathway leads to a reduced growth-promoting effect of adipocyte exosomes.

Conclusion

Taken together, our findings provide new insights into the role of adipocyte exosomes in the tumor microenvironment.

Obesity-Altered Adipose Stem Cells Promote ER⁺ Breast Cancer Metastasis through Estrogen Independent Pathways

Adipose stem cells (ASCs) play an essential role in tumor microenvironments. These cells are altered by obesity (obASCs) and previous studies have shown that obASCs secrete higher levels of leptin. Increased leptin, which upregulates estrogen receptor alpha (ERα) and aromatase, enhances estrogen bioavailability and signaling in estrogen receptor positive (ER⁺) breast cancer (BC) tumor growth and metastasis. In this study, we evaluate the effect of obASCs on ER⁺BC outside of the ERα signaling axis using breast cancer models with constitutively active ERα resulting from clinically relevant mutations (Y537S and D538G). We found that while obASCs promote tumor growth and proliferation, it occurs mostly through abrogated estrogen signaling when BC has constitutive ER activity. However, obASCs have a similar promotion of metastasis irrespective of ER status, demonstrating that obASC promotion of metastasis may not be completely estrogen dependent. We found that obASCs upregulate two genes in both ER wild type (WT) and ER mutant (MUT) BC: SERPINE1 and ABCB1. This study demonstrates that obASCs promote metastasis in ER WT and MUT xenografts and an ER MUT patient derived xenograft (PDX) model. However, obASCs promote tumor growth only in ER WT xenografts.

[Role of adipose tissue in the development and progression of colorectal cancer]

The paper gives the current data available in the literature on the relationship and pathogenetic mechanisms of influence of adipose tissue on colorectal carcinogenesis. It considers the aspects of changes in adipose tissue and microenvironment of the tumor itself, including those under the influence of biologically active substances secreted by adipocytes; differences in subcutaneous and visceral fat and their importance in the development and progression of colorectal cancer (CRC), as well as the role of adipose tissue-derived stem cells. Understanding these mechanisms for adipose tissue influence on CRC will assist not only in preventing this disease, but also in searching for new therapeutic targets.

PDGF enhances the protective effect of adipose stem cell-derived extracellular vesicles in a model of acute hindlimb ischemia

We previously have shown that platelet-derived growth factor (PDGF) modulates the biological activity of extracellular vesicles released by adipose-derived mesenchymal stem cells (ASC-EVs). ASC-EVs may interact with blood and vessel cells by transferring proteins and nucleic acids and regulate their functions. In this study, we investigated immunomodulatory activity and protection from acute hindlimb ischemia of EVs released by PDGF-stimulated ASC (PDGF-EVs). PDGF treatment of ASC changed protein and RNA composition of released EVs by enhancing the expression of anti-inflammatory and immunomodulatory factors. In vitro, control EVs (cEVs) derived from non-stimulated ASC increased the secretion of both the IL-1b, IL-17, IFNγ, TNFα pro-inflammatory factors and the IL-10 anti-inflammatory factor, and enhanced the in vitro peripheral blood mononuclear cell (PBMC) adhesion on endothelium. In contrast, PDGF-EVs enhanced IL-10 secretion and induced TGF-β1 secretion by PBMC. Moreover, PDGF-EVs stimulated the formation of T regulatory cells. In vivo, PDGF-EVs protected muscle tissue from acute ischemia, reduced infiltration of inflammatory cells and increased T regulatory cell infiltration in respect to cEVs. Our results suggest that PDGF-EVs are enriched in anti-inflammatory and immunomodulatory factors and induced in PBMC an enhanced production of IL-10 and TGF-β1 resulting in protection of muscle from acute ischemia in vivo.

Obesity and gastrointestinal cancer: the interrelationship of adipose and tumour microenvironments

Increasing recognition of an association between obesity and many cancer types exists, but how the myriad of local and systemic effects of obesity affect key cellular and non-cellular processes within the tumour microenvironment (TME) relevant to carcinogenesis, tumour progression and response to therapies remains poorly understood. The TME is a complex cellular environment in which the tumour exists along with blood vessels, immune cells, fibroblasts, bone marrow-derived inflammatory cells, signalling molecules and the extracellular matrix. Obesity, in particular visceral obesity, might fuel the dysregulation of key pathways relevant to both the adipose microenvironment and the TME, which interact to promote carcinogenesis in at-risk epithelium. The tumour-promoting effects of obesity can occur at the local level as well as systemically via circulating inflammatory, growth factor and metabolic mediators associated with adipose tissue inflammation, as well as paracrine and autocrine effects. This Review explores key pathways linking visceral obesity and gastrointestinal cancer, including inflammation, hypoxia, altered stromal and immune cell function, energy metabolism and angiogenesis.

Obesity-Activated Adipose-Derived Stromal Cells Promote Breast Cancer Growth and Invasion

Obese women diagnosed with breast cancer have an increased risk for metastasis, and the underlying mechanisms are not well established. Within the mammary gland, adipose-derived stromal cells (ASCs) are heterogeneous cells with the capacity to differentiate into multiple mesenchymal lineages. To study the effects of obesity on ASCs, mice were fed a control diet (CD) or high-fat diet (HFD) to induce obesity, and ASCs were isolated from the mammary glands of lean and obese mice. We observed that obesity increased ASCs proliferation, decreased differentiation potential, and upregulated expression of α-smooth muscle actin, a marker of activated fibroblasts, compared to ASCs from lean mice. To determine how ASCs from obese mice impacted tumor growth, we mixed ASCs isolated from CD- or HFD-fed mice with mammary tumor cells and injected them into the mammary glands of lean mice. Tumor cells mixed with ASCs from obese mice grew significantly larger tumors and had increased invasion into surrounding adipose tissue than tumor cells mixed with control ASCs. ASCs from obese mice demonstrated enhanced tumor cell invasion in culture, a phenotype associated with increased expression of insulin-like growth factor-1 (IGF-1) and abrogated by IGF-1 neutralizing antibodies. Weight loss induced in obese mice significantly decreased expression of IGF-1 from ASCs and reduced the ability of the ASCs to induce an invasive phenotype. Together, these results suggest that obesity enhances local invasion of breast cancer cells through increased expression of IGF-1 by mammary ASCs, and weight loss may reverse this tumor-promoting phenotype.

Deficient primary cilia in obese adipose-derived mesenchymal stem cells: obesity, a secondary ciliopathy?

Obesity alters the composition, structure and function of adipose tissue, characterized by chronic inflammation, insulin resistance and metabolic dysfunction. Adipose-derived mesenchymal stem cells (ASCs) are responsible for cell renewal, spontaneous repair and immunomodulation in adipose tissue. Increasing evidence highlights that ASCs are deficient in obesity, and the underlying mechanisms are not well understood. We have recently shown that obese ASCs have defective primary cilia, which are shortened and unable to properly respond to stimuli. Impaired cilia compromise ASC functions. This work suggests an intertwined connection of obesity, defective cilia and dysfunctional ASCs. We have here discussed the current data regarding defective cilia in various cell types in obesity. Based on these observations, we hypothesize that obesity, a systemic chronic metainflammation, could impair cilia in diverse ciliated cells, like pancreatic islet cells, stem cells and hypothalamic neurons, making these critical cells dysfunctional by shutting down their signal sensors and transducers. In this context, obesity may represent a secondary form of ciliopathy induced by obesity-related inflammation and metabolic dysfunction. Reactivation of ciliated cells might be an alternative strategy to combat obesity and its associated diseases.

Glioblastoma Bystander Cell Therapy: Improvements in Treatment and Insights into the Therapy Mechanisms

A preclinical model of glioblastoma (GB) bystander cell therapy using human adipose mesenchymal stromal cells (hAMSCs) is used to address the issues of cell availability, quality, and feasibility of tumor cure. We show that a fast proliferating variety of hAMSCs expressing thymidine kinase (TK) has therapeutic capacity equivalent to that of TK-expressing hAMSCs and can be used in a multiple-inoculation procedure to reduce GB tumors to a chronically inhibited state. We also show that up to 25% of unmodified hAMSCs can be tolerated in the therapeutic procedure without reducing efficacy. Moreover, mimicking a clinical situation, tumor debulking previous to cell therapy inhibits GB tumor growth. To understand these striking results at a cellular level, we used a bioluminescence imaging strategy and showed that tumor-implanted therapeutic cells do not proliferate, are unaffected by GCV, and spontaneously decrease to a stable level. Moreover, using the CLARITY procedure for tridimensional visualization of fluorescent cells in transparent brains, we find therapeutic cells forming vascular-like structures that often associate with tumor cells. In vitro experiments show that therapeutic cells exposed to GCV produce cytotoxic extracellular vesicles and suggest that a similar mechanism may be responsible for the in vivo therapeutic effectiveness of TK-expressing hAMSCs.

Insight into the development of obesity: functional alterations of adipose-derived mesenchymal stem cells

Obesity is associated with a variety of disorders including cardiovascular diseases, diabetes mellitus and cancer. Obesity changes the composition and structure of adipose tissue, linked to pro-inflammatory environment, endocrine/metabolic dysfunction, insulin resistance and oxidative stress. Adipose-derived mesenchymal stem cells (ASCs) have multiple functions like cell renewal, spontaneous repair and homeostasis in adipose tissue. In this review article, we have summarized the recent data highlighting that ASCs in obesity are defective in various functionalities and properties including differentiation, angiogenesis, motility, multipotent state, metabolism and immunomodulation. Inflammatory milieu, hypoxia and abnormal metabolites in obese tissue are crucial for impairing the functions of ASCs. Further work is required to explore the precise molecular mechanisms underlying its alterations and impairments. Based on these data, we suggest that deregulated ASCs, possibly also other mesenchymal stem cells, are important in promoting the development of obesity. Restoration of ASCs/mesenchymal stem cells might be an additional strategy to combat obesity and its associated diseases.