Nanoparticle-linked antagonist for leptin signaling inhibition in breast cancer

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

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

Targeting adipocyte-immune cell crosstalk to control breast cancer progression

Adipocytes are crucial components of breast cancer and are involved in regulating the progression, therapeutic efficacy, and prognosis of breast cancer patients. Characterized by storing energy and producing a variety of secretory factors, adipocytes are responsible for inducing obesity and regulating the tumor immune activity. Adipocytes communicate with tumor infiltrating immune cells through the secreted adipokines, cytokines, and exosomes in the breast cancer TIME, which shapes the tumor supporting environment to facilitate the immune escape of tumor cells. In-depth studies of the crosstalk between adipocytes and TIME can not only provide a more comprehensive regulatory landscape of TIME, but also be conducive to screening novel targets for future precision targeted therapy. The aim of this review is to discuss recent studies for understanding the role of crosstalk between adipocytes and immune cells in shaping the breast cancer immune microenvironment.

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.

Endorsement of TNBC Biomarkers in Precision Therapy by Nanotechnology

Breast cancer is a heterogeneous disease which accounts globally for approximately 1 million new cases annually, wherein more than 200,000 of these cases turn out to be cases of triple-negative breast cancer (TNBC). TNBC is an aggressive and rare breast cancer subtype that accounts for 10-15% of all breast cancer cases. Chemotherapy remains the only therapy regimen against TNBC. However, the emergence of innate or acquired chemoresistance has hindered the chemotherapy used to treat TNBC. The data obtained from molecular technologies have recognized TNBC with various gene profiling and mutation settings that have helped establish and develop targeted therapies. New therapeutic strategies based on the targeted delivery of therapeutics have relied on the application of biomarkers derived from the molecular profiling of TNBC patients. Several biomarkers have been found that are targets for the precision therapy in TNBC, such as EGFR, VGFR, TP53, interleukins, insulin-like growth factor binding proteins, c-MET, androgen receptor, BRCA1, glucocorticoid, PTEN, ALDH1, etc. This review discusses the various candidate biomarkers identified in the treatment of TNBC along with the evidence supporting their use. It was established that nanoparticles had been considered a multifunctional system for delivering therapeutics to target sites with increased precision. Here, we also discuss the role of biomarkers in nanotechnology translation in TNBC therapy and management.

Leptin-Activity Modulators and Their Potential Pharmaceutical Applications

Leptin, a multifunctional hormone primarily, but not exclusively, secreted in adipose tissue, is implicated in a wide range of biological functions that control different processes, such as the regulation of body weight and energy expenditure, reproductive function, immune response, and bone metabolism. In addition, leptin can exert angiogenic and mitogenic actions in peripheral organs. Leptin biological activities are greatly related to its interaction with the leptin receptor. Both leptin excess and leptin deficiency, as well as leptin resistance, are correlated with different human pathologies, such as autoimmune diseases and cancers, making leptin and leptin receptor important drug targets. The development of leptin signaling modulators represents a promising strategy for the treatment of cancers and other leptin-related diseases. In the present manuscript, we provide an update review about leptin-activity modulators, comprising leptin mutants, peptide-based leptin modulators, as well as leptin and leptin receptor specific monoclonal antibodies and nanobodies.

Association of Adipose Tissue and Adipokines with Development of Obesity-Induced Liver Cancer

Obesity is rapidly dispersing all around the world and is closely associated with a high risk of metabolic diseases such as insulin resistance, dyslipidemia, and nonalcoholic fatty liver disease (NAFLD), leading to carcinogenesis, especially hepatocellular carcinoma (HCC). It results from an imbalance between food intake and energy expenditure, leading to an excessive accumulation of adipose tissue (AT). Adipocytes play a substantial role in the tumor microenvironment through the secretion of several adipokines, affecting cancer progression, metastasis, and chemoresistance via diverse signaling pathways. AT is considered an endocrine organ owing to its ability to secrete adipokines, such as leptin, adiponectin, resistin, and a plethora of inflammatory cytokines, which modulate insulin sensitivity and trigger chronic low-grade inflammation in different organs. Even though the precise mechanisms are still unfolding, it is now established that the dysregulated secretion of adipokines by AT contributes to the development of obesity-related metabolic disorders. This review focuses on several obesity-associated adipokines and their impact on obesity-related metabolic diseases, subsequent metabolic complications, and progression to HCC, as well as their role as potential therapeutic targets. The field is rapidly developing, and further research is still required to fully understand the underlying mechanisms for the metabolic actions of adipokines and their role in obesity-associated HCC.

Leptin Signaling Affects Survival and Chemoresistance of Estrogen Receptor Negative Breast Cancer

Estrogen-receptor-negative breast cancer (BCER-) is mainly treated with chemotherapeutics. Leptin signaling can influence BCER- progression, but its effects on patient survival and chemoresistance are not well understood. We hypothesize that leptin signaling decreases the survival of BCER- patients by, in part, inducing the expression of chemoresistance-related genes. The correlation of expression of leptin receptor (OBR), leptin-targeted genes (CDK8, NANOG, and RBP-Jk), and breast cancer (BC) patient survival was determined from The Cancer Genome Atlas (TCGA) mRNA data. Leptin-induced expression of proliferation and chemoresistance-related molecules was investigated in triple-negative BC (TNBC) cells that respond differently to chemotherapeutics. Leptin-induced gene expression in TNBC was analyzed by RNA-Seq. The specificity of leptin effects was assessed using OBR inhibitors (shRNA and peptides). The results show that OBR and leptin-targeted gene expression are associated with lower survival of BCER- patients. Importantly, the co-expression of these genes was also associated with chemotherapy failure. Leptin signaling increased the expression of tumorigenesis and chemoresistance-related genes (ABCB1, WNT4, ADHFE1, TBC1D3, LL22NC03, RDH5, and ITGB3) and impaired chemotherapeutic effects in TNBC cells. OBR inhibition re-sensitized TNBC to chemotherapeutics. In conclusion, the co-expression of OBR and leptin-targeted genes may be used as a predictor of survival and drug resistance of BCER- patients. Targeting OBR signaling could improve chemotherapeutic efficacy.

Roles of omental and bone marrow adipocytes in tumor biology

Accumulating evidence highlights the importance of interactions between tumour cells and stromal cells for tumour initiation, progression, and metastasis. In tumours that contain adipocyte in their stroma, adipocytes contribute to modification of tumour microenvironment and affect metabolism of tumour and tumour progression by production of cytokines and adipokines from the lipids. The omentum and bone marrow (BM) are highly adipocyte-rich and are also common metastatic and primary tumour developmental sites. Omental adipocytes exhibit metabolic cross-talk, immune modulation, and angiogenesis. BM adipocytes secrete adipokines, and participate in solid tumour metastasis through regulation of the CCL2/CCR2 axis and metabolic interactions. BM adipocytes also contribute to the progression of hematopoietic neoplasms. Here, we here provide an overview of research progress on the cross-talks between omental/BM adipocytes and tumour cells, which may be pivotal modulators of tumour biology, thus highlighting novel therapeutic targets.

Abbreviations: MCP-1, monocyte chemoattractant protein 1IL, interleukinSTAT3, signal transducer and activator of transcription 3FABP4, fatty acid binding protein 4PI3K/AKT, phosphoinositide 3-kinase/protein kinase BPPAR, peroxisome proliferator-activated receptorPUFA, polyunsaturated fatty acidTAM, tumour-associated macrophagesVEGF, vascular endothelial growth factorVEGFR, vascular endothelial growth factor receptorBM, bone marrowBMA, bone marrow adipocytesrBMA, regulated BMAcBMA, constitutive BMAUCP-1, uncoupling protein-1TNF-α, tumour necrosis factor-alphaRANKL, receptor activator of nuclear factor kappa-Β ligandVCAM-1, vascular cell adhesion molecule 1JAK2, Janus kinase 2CXCL (C–X–C motif) ligandPGE2, prostaglandin E2COX-2, cyclooxygenase-2CCL2, C-C motif chemokine ligand 2NF-κB, nuclear factor-kappa BMM, multiple myelomaALL, acute lymphoblastic leukemiaAML, acute myeloid leukemiaGDF15, growth differentiation factor 15AMPK, AMP-activated protein kinaseMAPK, mitogen-activated protein kinaseAPL, acute promyelocytic leukemiaCCR2, C-C motif chemokine receptor 2SDF-1α, stromal cell-derived factor-1 alphaFFA, free fatty acidsLPrA, leptin peptide receptor antagonistMCD, malonyl-CoA decarboxylase.

Leptin-induced Notch and IL-1 signaling crosstalk in endometrial adenocarcinoma is associated with invasiveness and chemoresistance

BACKGROUND

Obesity is a recognized risk factor for endometrial cancer (EmCa) and other cancer types. Leptin levels are significantly increased in obese individuals. Leptin-induced signaling crosstalk [Notch, Interleukin-1 (IL-1) and leptin outcome, NILCO] has been associated with breast cancer progression. This complex signaling crosstalk affects cancer cell proliferation, migration, invasion, angiogenesis, apoptosis and chemoresistance. NILCO expression was previously detected in human EmCa. However, it is unknown whether leptin regulates NILCO and alters EmCa’s response to chemotherapeutics. It is hypothesized that leptin induces NILCO and increases aggressiveness and chemoresistance in EmCa cells.

AIM

To determine whether leptin induces NILCO molecules in EmCa affecting cell proliferation, aggressiveness and chemoresistance.

METHODS

Leptin’s effects on the expression of NILCO molecules [mRNAs and proteins for Notch receptors (Notch1-4), ligands (JAG1 and DLL4) and downstream effectors (survivin, Hey2), and leptin (OB-R) and IL-1 (IL-1R tI) receptors] was examined in EmCa cells (type I: Ishikawa, and HEC-1A, and type II: An3Ca and KLE) using Real-time PCR and Western blot analysis, respectively. In addition, the effects of leptin on cell cycle, proliferation and cell invasion were determined using cytometric analysis (Cellometer Vision CBA system), MTT cell proliferation and Matrigel-based invasion assays, respectively. Inhibitors of leptin (nanoparticle-bound leptin peptide receptor antagonist-2, IONP-LPrA2), IL-1 (anti-IL-1R tI antibody) and Notch (siRNA interference RNA) were used to investigate NILCO’s effects on cell proliferation and invasion. Leptin’s effects on Paclitaxel cytotoxicity in EmCa cells was determined by the CCK8 and Cellometer-based Annexin V assays.

RESULTS

For the first time it was shown that leptin is an inducer of Notch in EmCa. Experimental data suggest that leptin induced the expression of NILCO molecules, promoted proliferation and S- phase progression, and reduced Paclitaxel cytotoxicity on EmCa cells. Leptin’s effects were higher in type II EmCa cells. The progression of this more aggressive form of the disease is associated with obesity. Remarkably, the use of the leptin signaling antagonist, IONP-LPrA2, re-sensitized EmCa cells to Paclitaxel.

CONCLUSION

Present data suggest the notion that leptin-induced NILCO could be a link between obesity and EmCa progression and chemoresistance. Most aggressive type II EmCa cells were higher sensitive to leptin, which appears to increase proliferation, cell cycle progression, aggressiveness, and chemoresistance to Paclitaxel. Therefore, leptin and NILCO could be novel therapeutic targets for type II EmCa, which does not have targeted therapy. Overall, IONP-LPrA2 has a potential as a novel adjuvant drug to enhance the effectiveness of type II EmCa chemotherapy.

Leptin-induced signaling pathways in cancer cell migration and invasion

BACKGROUND

Increasing evidence indicates that obesity is associated with tumor development and progression. Leptin is an adipocyte-related hormone with a key role in energy metabolism and whose circulating levels are elevated in obesity. The effect of leptin on cancer progression and metastasis and its underlying mechanisms are still unclear. Leptin can impact various steps in tumor metastasis, including epithelial-mesenchymal transition, cell adhesion to the extracellular matrix (ECM), and proteolysis of ECM components. To do so, leptin binds to its receptor (OB-Rb) to activate signaling pathways and downstream effectors that participate in tumor cell invasion as well as distant metastasis.

CONCLUSIONS

In this review, we describe metastasis steps in detail and characterize metastasis-related molecules activated by leptin, which may help to develop a roadmap that guides future work. In addition, we conclude that a profound understanding of the fundamental molecular processes that contribute to leptin-induced metastasis may pave the way for the development of new prognostic molecules and appropriate approaches to the treatment of obesity-related cancers.

Protein/ Hormone Based Nanoparticles as Carriers for Drugs Targeting Protein-Protein Interactions

BACKGROUND

In this review, protein-protein interactions (PPIs) were defined, and their behaviors in normal in disease conditions are discussed. Their status at nuclear, molecular and cellular level was underscored, as for their interference in many diseases. Finally, the use of protein nanoscale structures as possible carriers for drugs targeting PPIs was highlighted.

OBJECTIVE

The objective of this review is to suggest a novel approach for targeting PPIs. By using protein nanospheres and nanocapsules, a promising field of study can be emerged.

METHODS

To solidify this argument, PPIs and their biological significance was discussed, same as their role in hormone signaling.

RESULTS

We shed the light on the drugs that targets PPI and we suggested the use of nanovectors to encapsulate these drugs to possibly achieve better results.

CONCLUSION

Protein based nanoparticles, due to their advantages, can be suitable carriers for drugs targeting PPIs. This can open a new opportunity in the emerging field of multifunctional therapeutics.

Adipokines as therapeutic targets in breast cancer treatment

INTRODUCTION

Adipocytes, which represent a substantial part of the tumor microenvironment in breast cancer, secrete several adipokines that affect tumorigenesis, cancer progression, metastasis, and treatment resistance via multiple signaling pathways. Areas covered: In this review, we focus on the role of leptin, adiponectin, autotaxin, and interleukin-6 in breast cancer initiation, progression, metastasis, and drug response. Furthermore, we investigated adipokines as potential targets of breast cancer-specific drugs. Expert opinion: Adipokines and adipokine receptors are deregulated in breast cancer. Adipokines play various roles in breast cancer initiation, progression, metastasis, and drug response, hence, adipokine signaling could be an effective drug target. Several clinical trials are in progress to test the efficacy of adipokine targeting agents. However, adipokines also affect metabolic homeostasis; hence, the adverse effects of the targeted drug should be investigated and addressed.

Non-Platinum Metal Complexes as Potential Anti-Triple Negative Breast Cancer Agents

Breast cancer (BC) is the most common cancer in women worldwide, with a mortality rate that has been forecasted to rise in the next decade. This is especially worrying for people with triple-negative BC (TNBC), because of its unresponsiveness to current therapies. Different drugs to treat TNBC have been assessed, and, although platinum chemotherapy drugs seem to offer some hope, their drawbacks have motivated extensive investigations into alternative metal-based BC therapies. This paper aims to: (i) describe the preliminary in vitro and in vivo anticancer properties of non-platinum metal-based complexes (NPMBC) against TNBC; and (ii) analyze the likely molecular targets involved in their anticancer activity.

Leptin-Notch axis impairs 5-fluorouracil effects on pancreatic cancer

5-FU chemotherapy is a current strategy to treat pancreatic cancer (PC), but unfortunately chemoresistance is eventually developed in most patients. Obesity is a risk factor for PC that could affect 5-FU effectiveness through the adipokine leptin, which is a known proliferation, survival factor and Notch inducer. We investigated whether leptin signaling affects 5-FU cytotoxicity on PC. To this end, tumorspheres developed from BxPC-3 and MiaPaCa-2 PC cells were treated with 5-FU, leptin, inhibitors for Notch (DAPT) and leptin signaling (IONP-LPrA2) and ATP-binding cassette of proteins (Probenecid). Leptin treatment decreased 5-FU cytotoxicity, and increased cell proliferation, colony forming ability, stem cell, pluripotency, EMT markers, drug efflux proteins (ABCC5, ABCC11) and Notch. In addition, leptin reduced the 5-FU effects on apoptosis by decreasing pro-apoptotic (Bax, Caspase-3 activation and PARP degradation) and increasing anti-apoptotic factors (RIP and Bcl-XL). Leptin's effects on PC tumorspheres treated with 5-FU were reduced by IONP-LPrA2 and were mainly Notch signaling- dependent and more evident in MiaPaCa-2-derived tumorspheres. Present results suggest that leptin could impair 5-FU cytotoxicity and promote chemoresistance. Therefore, targeting the leptin-Notch axis could be a novel way to improve 5-FU therapy for PC patients, especially in obesity context.

Food intake regulation by leptin: Mechanisms mediating gluconeogenesis and energy expenditure

Regulation of blood glucose levels and body fat is critical for survival. Leptin circulates freely in blood and controls body weight and food intake mainly through hypothalamic receptors and regulates glucose metabolism in the liver both directly through leptin receptors and indirectly via the hypothalamic receptors of central nervous system. Leptin affects food intake regulation and eventually glucose metabolism, lipometabolism, endocrine and immune functions, reproductive function, adipose tissue metabolism and energy expenditure. Leptin also exerts peripheral effects directly on glucose metabolism and gluconeogenesis. Most of obese human subjects have elevated plasma levels of leptin associated to the size of their total adipose tissue mass. Hence gluconeogenic function may be an essential factor in the regulation of nutritional intake and weight gain. The aim of this review is therefore to identify and module the possible effects of leptin with special application in gluconeogenesis. In addition, this review includes the study of fat consumption and energy expenditure in the body. Specific modulation of leptin receptors and adipose tissues functioning could have important inference on therapeutic strategies.

Type II Endometrial Cancer Overexpresses NILCO: A Preliminary Evaluation

OBJECTIVE

The expression of NILCO molecules (Notch, IL-1, and leptin crosstalk outcome) and the association with obesity were investigated in types I and II endometrial cancer (EmCa). Additionally, the involvement of NILCO in leptin-induced invasiveness of EmCa cells was investigated.

METHODS

The expression of NILCO mRNAs and proteins were analyzed in EmCa from African-American (n = 29) and Chinese patients (tissue array, n = 120 cases). The role of NILCO in leptin-induced invasion of Ishikawa and An3ca EmCa cells was investigated using Notch, IL-1, and leptin signaling inhibitors.

RESULTS

NILCO molecules were expressed higher in type II EmCa, regardless of ethnic background or obesity status of patients. NILCO proteins were mainly localized in the cellular membrane and cytoplasm of type II EmCa. Additionally, EmCa from obese African-American patients showed higher levels of NILCO molecules than EmCa from lean patients. Notably, leptin-induced EmCa cell invasion was abrogated by NILCO inhibitors.

CONCLUSION

Type II EmCa expressed higher NILCO molecules, which may suggest it is involved in the progression of the more aggressive EmCa phenotype. Obesity was associated with higher expression of NILCO molecules in EmCa. Leptin-induced cell invasion was dependent on NILCO. Hence, NILCO might be involved in tumor progression and could represent a new target/biomarker for type II EmCa.

Leptin signaling and cancer chemoresistance: Perspectives

Obesity is a major health problem and currently is endemic around the world. Obesity is a risk factor for several different types of cancer, significantly promoting cancer incidence, progression, poor prognosis and resistance to anti-cancer therapies. The study of this resistance is critical as development of chemoresistance is a serious drawback for the successful and effective drug-based treatments of cancer. There is increasing evidence that augmented adiposity can impact on chemotherapeutic treatment of cancer and the development of resistance to these treatments, particularly through one of its signature mediators, the adipokine leptin. Leptin is a pro-inflammatory, pro-angiogenic and pro-tumorigenic adipokine that has been implicated in many cancers promoting processes such as angiogenesis, metastasis, tumorigenesis and survival/resistance to apoptosis. Several possible mechanisms that could potentially be developed by cancer cells to elicit drug resistance have been suggested in the literature. Here, we summarize and discuss the current state of the literature on the role of obesity and leptin on chemoresistance, particularly as it relates to breast and pancreatic cancers. We focus on the role of leptin and its significance in possibly driving these proposed chemoresistance mechanisms, and examine its effects on cancer cell survival signals and expansion of the cancer stem cell sub-populations.