Leptin regulates proliferation and apoptosis of colorectal carcinoma through PI3K/Akt/mTOR signalling pathway

Crosstalk between MiRNAs/lncRNAs and PI3K/AKT signaling pathway in diabetes mellitus: Mechanistic and therapeutic perspectives

Diabetes as a fastest growing diseases worldwide is characterized by elevated blood glucose levels. There's an enormous financial burden associated with this endocrine disorder, with unequal access to health care between developed and developing countries. PI3Ks (phosphoinositide 3-kinases) have been demonstrated to be crucial for glucose homeostasis, and malfunctioning of these molecules can contribute to an increase in glucose serum levels, the main pathophysiological feature of diabetes. Additionally, recent evidence suggests that miRNAs and lncRNAs are reciprocally interacting with this signaling pathway. It is therefore evident that abnormal regulation of miRNAs/lncRNAs in the lncRNAs/miRNAs/PI3K/AKT axis is related to clinicopathological characteristics and plays a crucial role in the regulation of biological processes. It has therefore been attempted in this review to describe the interaction between PI3K/AKT signaling pathway and various miRNAs/lncRNAs and their importance in DM biology. We also presented the clinical applications of PI3K/AKT-related ncRNAs/herbal medicine in patients with DM.

Inflammation and cancer: friend or foe?

Chronic inflammation plays a crucial role in the onset and progression of pathologies like neurodegenerative and cardiovascular diseases, diabetes, and cancer, since tumor development and chronic inflammation are linked, sharing common signaling pathways. At least 20% of breast and colorectal cancers are associated with chronic inflammation triggered by infections, irritants, or autoimmune diseases. Obesity, chronic inflammation, and cancer interconnection underscore the importance of population-based interventions in maintaining healthy body weight, to disrupt this axis. Given that the dietary inflammatory index is correlated with an increased risk of cancer, adopting an anti-inflammatory diet supplemented with nutraceuticals may be useful for cancer prevention. Natural products and their derivatives offer promising antitumor activity with favorable adverse effect profiles; however, the development of natural bioactive drugs is challenging due to their variability and complexity, requiring rigorous research processes. It has been shown that combining anti-inflammatory products, such as non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and statins, with plant-derived products demonstrate clinical utility as accessible adjuvants to traditional therapeutic approaches, with known safety profiles. Pharmacological approaches targeting multiple proteins involved in inflammation and cancer pathogenesis emerge as a particularly promising option. Given the systemic and multifactorial nature of inflammation, comprehensive strategies are essential for long term success in cancer therapy. To gain insights into carcinogenic phenomena and discover diagnostic or clinically relevant biomarkers, is pivotal to understand genetic variability, environmental exposure, dietary habits, and TME composition, to establish therapeutic approaches based on molecular and genetic analysis. Furthermore, the use of endocannabinoid, cannabinoid, and prostamide-type compounds as potential therapeutic targets or biomarkers requires further investigation. This review aims to elucidate the role of specific etiological agents and mediators contributing to persistent inflammatory reactions in tumor development. It explores potential therapeutic strategies for cancer treatment, emphasizing the urgent need for cost-effective approaches to address cancer-associated inflammation.

Immunometabolic Profile Associated with Progressive Damage of the Intestinal Mucosa in Adults Screened for Colorectal Cancer: Association with Diet

Environmental factors such as diet and lifestyle have been shown to influence the development of some intestinal mucosal lesions that may be precursors of colorectal cancer (CRC). The presence of these alterations seems to be associated with misbalanced immunological parameter levels. However, it is still unclear as to which immunological parameters are altered in each phase of CRC development. In this work, we aimed to study the potential relationships of immunological and metabolic parameters with diet in a CRC-related lesion context. Dietary information was obtained using an annual semi-quantitative food-frequency questionnaire (FFQ) from 93 volunteers classified via colonoscopy examination according to the presence of intestinal polyps or adenocarcinoma. Cytokines, chemokines, and adipokines were determined from serum samples. We observed a reduction in adiponectin according to the damage to the mucosa, accompanied by an increase and decrease in C-X-C motif chemokine ligand 10 (CXCL10) and resistin, respectively, in CRC cases. The presence of aberrant crypt foci (ACF) in the polyp group was associated with higher tumor necrosis factor-alpha (TNF-α) concentrations. Vegetables were directly correlated with adiponectin and resistin levels, while the opposite occurred with red meat. A bioactive compound, soluble pectin, showed a negative association with TNF-α. Future dietary strategies could be developed to modulate specific immunological parameters in the context of CRC.

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.

The Effect of Serum Leptin Concentration and Leptin Receptor Expression on Colorectal Cancer

INTRODUCTION

The level of leptin in the blood shows a positive, strong correlation with the mass of adipose tissue. Being overweight and having metabolic disorders increase the risk of developing colorectal cancer.

AIM OF THE PAPER

The aim of the study was to assess the concentration of leptin in the blood serum as well as the expression of the leptin receptor in colorectal cancer cells. In addition, the effect of serum leptin concentration and leptin receptor expression on clinical and pathological parameters such as BMI, obesity, TNM, and tumor size was assessed.

METHODS

The study included 61 patients diagnosed with colorectal cancer and treated with surgery.

RESULTS

Strong leptin receptor expression and the prevalence of overweight and obesity are factors influencing the occurrence of excessive leptin concentrations.

CONCLUSION

Leptin may be involved in the development and progression of colorectal cancer. More research is needed to better elucidate the role of leptin in the development and progression of the disease.

Sex-Dependent Differences in Colorectal Cancer: With a Focus on Obesity

Colorectal cancer (CRC) is the third most common cancer and has the second highest cancer-related mortality in the world. The incident rates of CRC vary country-wise; however, population studies and data from different countries show a general increase in the CRC rate in young adults, males, and females ≥65 years. CRC incidence is affected by age, sex, environmental, dietary, hormonal, and lifestyle factors. Obesity is a known disease that is spreading rapidly throughout the world. A large body of literature indicates that, among many conditions, obesity is the increasing cause of CRC. Even though obesity is one of the known factors for CRC development, limited studies are available that explain the mechanistic link between obesity, sex hormones, and CRC development. Thus, this review summarizes the literature and aims to understand sex-dependent differences in CRC, especially in the context of obesity.

Current knowledge of leptin in wound healing: A collaborative review

Efficacious wound healing is still a major concern for global healthcare due to the unsatisfactory outcomes under the current treatments. Leptin, an adipocyte-derived hormone, mainly acts in the hypothalamus and plays crucial roles in various biological processes. Recently, an increasing number of researches have shown that leptin played an important role in the wound healing process. In this review, we presented a first attempt to capture the current knowledge on the association between leptin and wound healing. After a comprehensive review, the molecular mechanisms underlying leptin in wound healing were speculated to be correlated to the regulation of inflammation of the macrophage and lymphocytes, angiogenesis, re-epithelialization, proliferation, and differentiation of fibroblasts. The affected genes and the signal pathways were multiple. For example, leptin was reported to ameliorate wound healing by its anti-inflammatory action, which might be correlated to the activation STAT1 and STAT3 via p38 MAPK or JAK2. However, the understanding of the specific role in each process (e.g., inflammatory, proliferative, and maturation phase) of wound repair is not entirely clear, and further studies are still warranted in both macrostructural and microscale factors. Therefore, identifying and validating the biological mechanisms of leptin in wound healing is of great significance to develop potential therapeutic targets for the treatment of wound healing in clinical practice.

AKT inhibition sensitizes EVI1 expressing colon cancer cells to irinotecan therapy by regulating the Akt/mTOR axis

PURPOSE

Ecotropic viral integration site 1 (EVI1) is an oncogenic transcription factor that has been attributed to chemotherapy resistance in different cancers. As yet, however, its role in colon cancer drug resistance is not completely understood. Here, we set out to investigate the functional and therapeutic relevance of EVI1 in colon cancer drug resistance.

METHODS

The EVI1 gene was knocked down in colon cancer cells that were subsequently tested for susceptibility to irinotecan using in vitro assays and in vivo subcutaneous mouse colon cancer models. The effect of EVI1 knockdown on the AKT-mTOR signaling pathway was assessed using cell line models, immunohistochemistry and bioinformatics tools. The anti-proliferative activity of AKT inhibitor GSK690693 and its combination with irinotecan was tested in colon cancer cell line models (2D and 3D). Finally, the therapeutic efficacy of GSK690693 and its combination with irinotecan was evaluated in xenografted EVI1 expressing colon cancer mouse models.

RESULTS

We found that EVI1 knockdown decreased cancer stem cell-like properties and improved irinotecan responses in both cell line and subcutaneous mouse models. In addition, we found that EVI1 downregulation resulted in inhibition of AKT/mTOR signaling and RICTOR expression. Knocking down RICTOR expression increased the cytotoxic effects of irinotecan in EVI1 downregulated colon cancer cells. Co-treatment with irinotecan and ATP-competitive AKT inhibitor GSK690693 significantly reduced colon cancer cell survival and tumor progression rates.

CONCLUSION

Inhibition of the AKT signaling cascade by GSK690693 may serve as an alternative to improve the irinotecan response in EVI1-expressing colon cancer cells.

Targeting mTOR in the Context of Diet and Whole-body Metabolism

The mechanistic target of the rapamycin (mTOR) signaling pathway is the central regulator of cell growth and proliferation by integrating growth factor and nutrient availability. Under healthy physiological conditions, this process is tightly coordinated and essential to maintain whole-body homeostasis. Not surprisingly, dysregulated mTOR signaling underpins several diseases with increasing incidence worldwide, including obesity, diabetes, and cancer. Consequently, there is significant clinical interest in developing therapeutic strategies that effectively target this pathway. The transition of mTOR inhibitors from the bench to bedside, however, has largely been marked with challenges and shortcomings, such as the development of therapy resistance and adverse side effects in patients. In this review, we discuss the current status of first-, second-, and third-generation mTOR inhibitors as a cancer therapy in both preclinical and clinical settings, with a particular emphasis on the mechanisms of drug resistance. We focus especially on the emerging role of diet as an important environmental determinant of therapy response, and posit a conceptual framework that links nutrient availability and whole-body metabolic states such as obesity with many of the previously defined processes that drive resistance to mTOR-targeted therapies. Given the role of mTOR as a central integrator of cell metabolism and function, we propose that modulating nutrient inputs through dietary interventions may influence the signaling dynamics of this pathway and compensatory nodes. In doing so, new opportunities for exploiting diet/drug synergies are highlighted that may unlock the therapeutic potential of mTOR inhibitors as a cancer treatment.

Reducing PDK1/Akt Activity: An Effective Therapeutic Target in the Treatment of Alzheimer's Disease

Alzheimer’s disease (AD) is a common age-related neurodegenerative disease that leads to memory loss and cognitive function damage due to intracerebral neurofibrillary tangles (NFTs) and amyloid-β (Aβ) protein deposition. The phosphoinositide-dependent protein kinase (PDK1)/protein kinase B (Akt) signaling pathway plays a significant role in neuronal differentiation, synaptic plasticity, neuronal survival, and neurotransmission via the axon–dendrite axis. The phosphorylation of PDK1 and Akt rises in the brain, resulting in phosphorylation of the TNF-α-converting enzyme (TACE) at its cytoplasmic tail (the C-terminal end), changing its internalization as well as its trafficking. The current review aimed to explain the mechanisms of the PDK1/Akt/TACE signaling axis that exerts its modulatory effect on AD physiopathology. We provide an overview of the neuropathological features, genetics, Aβ aggregation, Tau protein hyperphosphorylation, neuroinflammation, and aging in the AD brain. Additionally, we summarized the phosphoinositide 3-kinase (PI3K)/PDK1/Akt pathway-related features and its molecular mechanism that is dependent on TACE in the pathogenesis of AD. This study reviewed the relationship between the PDK1/Akt signaling pathway and AD, and discussed the role of PDK1/Akt in resisting neuronal toxicity by suppressing TACE expression in the cell membrane. This work also provides a perspective for developing new therapeutics targeting PDK1/Akt and TACE for the treatment of AD.

eQTL Highlights the Potential Role of Negative Control of Innate Immunity in Kawasaki Disease

Purpose

Kawasaki disease (KD) is an acute systemic vasculitis mainly found in the medium-sized arteries, especially the coronary arteries. Immune system is involved in the pathogenesis of acute KD in children, but the functional differences in the immune system between healthy children and KD patients remain unclear.

Patients and Methods

A total of 190 KD patients and 119 healthy controls were recruited for the next-generation sequencing of 512 targeted genes from 4 immune-related pathways. Subsequently, the peripheral blood mononuclear cells (PBMCs) were isolated. RNA sequencing of the LPS treated PBMCs from additional 20 KD patients and 20 healthy controls was used to examine the differentially expressed genes (DEGs). Then, an expression quantitative trait locus (eQTL) analysis combined with previously analyzed RNA data were used to examine the DEGs. Finally, the serum levels of 13 cytokines were detected before and after LPS treatment in 40 samples to confirm the findings from eQTL analysis.

Results

A total of 319 significant eQTL were found, and both eQTL analysis and RNA sequencing showed some DEGs were involved in the connective tissue disorders and inflammatory diseases. DEGs that function to negatively regulate immunity were closely related to the pathogenesis of KD. In addition, the serum levels of IL-10 (an inflammatory and immunosuppressive factor) and SCD25 (an important immunosuppressant) reduced significantly in the KD patients.

Conclusion

Our study shows the expression of factors responsible for the negative control of innate immunity is altered, which plays an important role in the etiology of KD.

The PI3K/Akt signaling axis in Alzheimer's disease: a valuable target to stimulate or suppress?

Among the long list of age-related complications, Alzheimer's disease (AD) has the most dreadful impact on the quality of life due to its devastating effects on memory and cognitive abilities. Although a plausible correlation between the phosphatidylinositol 3-kinase (PI3K) signaling and different processes involved in neurodegeneration has been evidenced, few articles reviewed the task. The current review aims to unravel the mechanisms by which the PI3K pathway plays pro-survival roles in normal conditions, and also to discuss the original data obtained from international research laboratories on this topic. Responses to questions on how alterations of the PI3K/Akt signaling pathway affect Tau phosphorylation and the amyloid cascade are given. In addition, we provide a general overview of the association between oxidative stress, neuroinflammation, alterations of insulin signaling, and altered autophagy with aberrant activation of this axis in the AD brain. The last section provides a special focus on the therapeutic possibility of the PI3K/Akt/mTOR modulators, either categorized as chemicals or herbals, in AD. In conclusion, determining the correct timing for the administration of the drugs seems to be one of the most important factors in the success of these agents. Also, the role of the PI3K/Akt signaling axis in the progression or repression of AD widely depends on the context of the cells; generally speaking, while PI3K/Akt activation in neurons and neural stem cells is favorable, its activation in microglia cells may be harmful.

Identification of vital genes and pathways associated with mucosal melanoma in Chinese

Mucosal melanoma is a rare malignant melanoma with more aggressive and poorer outcomes. The incidence of mucosal melanoma varies greatly among different ethnic groups. We herein sought to characterize the vital genes and pathways of Chinese mucosal melanoma patients. By whole-exome sequencing in six patients with mucosal melanoma, we detected a total of 21,733 CNVs and 2372 SNPs. The CNV/SNP burden varies greatly between individuals, including recurrent CNV targeting PIK3 family, KRAS, APC and BRCA1. Significantly mutated genes were NUDT5, ZBTB18, NEURL4, ZNF430, RBM44, GAK, PCDHA13, STK38 and UBR5. Besides, FAT1 gene was identified frequently mutated in anorectal melanoma patients (3/3, 100%). Moreover, our result showed that HPV infection may be associated with mucosal melanoma. In conclusion, this study indicated that mucosal melanomas have a low SNPs burden and a high number of CNVs and expand the spectrum of mucosal melanoma variants, also provided an insight for the pathological mechanism of mucosal melanoma.

Dietary Energy Modulation and Autophagy: Exploiting Metabolic Vulnerabilities to Starve Cancer

Cancer cells experience unique and dynamic shifts in their metabolic function in order to survive, proliferate, and evade growth inhibition in the resource-scarce tumor microenvironment. Therefore, identification of pharmacological agents with potential to reprogram cancer cell metabolism may improve clinical outcomes in cancer therapy. Cancer cells also often exhibit an increased dependence on the process known as autophagy, both for baseline survival and as a response to stressors such as chemotherapy or a decline in nutrient availability. There is evidence to suggest that this increased dependence on autophagy in cancer cells may be exploitable clinically by combining autophagy modulators with existing chemotherapies. In light of the increased metabolic rate in cancer cells, interest is growing in approaches aimed at "starving" cancer through dietary and pharmacologic interventions that reduce availability of nutrients and pro-growth hormonal signals known to promote cancer progression. Several dietary approaches, including chronic calorie restriction and multiple forms of fasting, have been investigated for their potential anti-cancer benefits, yielding promising results in animal models. Induction of autophagy in response to dietary energy restriction may underlie some of the observed benefit. However, while interventions based on dietary energy restriction have demonstrated safety in clinical trials, uncertainty remains regarding translation to humans as well as feasibility of achieving compliance due to the potential discomfort and weight loss that accompanies dietary restriction. Further induction of autophagy through dietary or pharmacologic metabolic reprogramming interventions may enhance the efficacy of autophagy inhibition in the context of adjuvant or neo-adjuvant chemotherapy. Nonetheless, it remains unclear whether therapeutic agents aimed at autophagy induction, autophagy inhibition, or both are a viable therapeutic strategy for improving cancer outcomes. This review discusses the literature available for the therapeutic potential of these approaches.

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.

Small Molecule Destabilizer of β-Catenin and Ras Proteins Antagonizes Growth of K-Ras Mutation-Driven Colorectal Cancers Resistant to EGFR Inhibitors

BACKGROUND

Oncogenic K-Ras mutations in colorectal cancer (CRC) combined with APC mutations worsen CRC prognosis and lower drug effectiveness. Thus, inhibition of both Wnt/β-catenin and Ras-MAPK signaling may be a rational strategy to improve the treatment of this cancer.

OBJECTIVE

To identify a novel compound inhibiting both Wnt/β-catenin and Ras-MAPK signaling in CRC.

METHODS AND PATIENTS

We developed a two-part screening system consisting of analysis of TOP flash reporter cells and then potential toxicity effects on primary neural stem cells (NSCs). We then screened 2000 chemical compounds and tested efficacy of candidates against isogenic colon cancer cells harboring wild-type or mutant K-Ras. We employed immunohistochemistry and immunocytochemistry to determine marker signatures associated with development of disease phenotypes.

RESULTS

We identified CPD0857, a compound that inactivates Wnt/β-catenin signaling and promotes ubiquitin-dependent proteasomal degradation of β-catenin and Ras proteins. CPD0857 effectively decreased proliferation and increased apoptosis of CRC cell lines, and overcame resistance of CRC harboring APC and K-Ras mutations to treatment with an EGFR monoclonal antibody (mAb). Moreover, CPD0857 attenuated invasiveness of highly migratory CRC cells in vitro. Accordingly, xenograft mice treated with CPD0857 showed slower tumor growth and significant decreases in both β-catenin and Ras protein expression.

CONCLUSIONS

CPD0857 may be a potential drug for treating aggressive CRC carrying mutations that aberrantly activate Wnt/β-catenin and Ras-ERK pathways.

Leptin Overexpression as a Poor Prognostic Factor for Colorectal Cancer

Leptin acts as an adipocytokine functions via the leptin receptor, which stimulates growth, migration, and invasion of cancer cells. This study is aimed at identifying leptin as a prognostic factor in colorectal cancer (CRC). The differentially expressed genes with prognostic value in CRC tissues either with or without liver metastasis were assessed based on The Cancer Genomic Atlas (TCGA). Leptin was considered a candidate gene for further analysis. Its expression features of 206 CRC patients without liver metastasis and 201 patients with metastasis on tissue microarrays were assessed by immunochemical staining, and the effect of leptin on survival was assessed by Kaplan-Meier analyses. Overexpressed leptin indicated a poorer prognosis for CRC patients in overall survival (p < 0.05, log-rank test) based on the TCGA database. The leptin expression significantly correlated with metastasis stage (p < .010) and lymph node involvement (p < .010). Multivariate analysis also indicated that strong leptin expression was an independent adverse prognosticator in CRC (p = .017). Leptin may be valued as a prognostic marker could contribute to predicting a clinical outcome for patients with CRC.

Leptin Overexpression as a Poor Prognostic Factor for Colorectal Cancer

Leptin acts as an adipocytokine functions via the leptin receptor, which stimulates growth, migration, and invasion of cancer cells. This study is aimed at identifying leptin as a prognostic factor in colorectal cancer (CRC). The differentially expressed genes with prognostic value in CRC tissues either with or without liver metastasis were assessed based on The Cancer Genomic Atlas (TCGA). Leptin was considered a candidate gene for further analysis. Its expression features of 206 CRC patients without liver metastasis and 201 patients with metastasis on tissue microarrays were assessed by immunochemical staining, and the effect of leptin on survival was assessed by Kaplan-Meier analyses. Overexpressed leptin indicated a poorer prognosis for CRC patients in overall survival (p < 0.05, log-rank test) based on the TCGA database. The leptin expression significantly correlated with metastasis stage (p < .010) and lymph node involvement (p < .010). Multivariate analysis also indicated that strong leptin expression was an independent adverse prognosticator in CRC (p = .017). Leptin may be valued as a prognostic marker could contribute to predicting a clinical outcome for patients with CRC.

Decrypting the Molecular Mechanistic Pathways Delineating the Chemotherapeutic Potential of Ruthenium-Phloretin Complex in Colon Carcinoma Correlated with the Oxidative Status and Increased Apoptotic Events

To explore fresh strategies in colorectal cancer (CRC) chemotherapy, we evaluated the capability of the ruthenium-phloretin complex in exterminating colon cancer by effectively addressing multiple apoptotic mechanisms on HT-29 cancer cells together with an animal model of colorectal cancer activated by 1,2-dimethylhydrazine and dextran sulfate sodium. Our current approach offers tangible evidence of the application of the ruthenium-phloretin complex in future chemotherapy. The complex triggers intrinsic apoptosis triggered by p53 and modulates the Akt/mTOR pathway along with other inflammatory biomarkers. The ruthenium-phloretin complex has been synthesized and successfully characterized by numerous spectroscopic methodologies accompanied by DPPH, FRAP, and ABTS assays assessing its antioxidant potential. Studies conducted in human cell lines revealed that the complex improved levels of p53 and caspase-3 while diminishing the activities of VEGF and mTOR, triggers apoptosis, and induces fragmentation of DNA in the HT-29 cells. Toxicity studies were conducted to identify the therapeutic doses of the novel complex in animal models. The outcomes of the in vivo report suggest that the complex was beneficial in repressing multiplicity of aberrant crypt foci as well as hyperplastic lesions and also promoted increased levels of CAT, SOD, and glutathione. In addition, the ruthenium-phloretin complex was able to control cell proliferation and boosted apoptotic outbursts in cancer cells associated with the increase in cellular response towards Bax while diminishing responses towards Bcl-2, NF-κB, and MMP-9. Our observations from the experiments deliver testament that the ruthenium-phloretin complex has the potential to act as a promising chemotherapeutic agent in colorectal cancer because it can affect the growth of ACF and hyperplastic abrasions in the colon tissues by evoking cell death.

Cardiovascular diseases and metabolic abnormalities associated with obesity: What is the role of inflammatory responses? A systematic review

INTRODUCTION

Obesity is a chronic disease responsible for a high morbidity and mortality rate, with an increasing worldwide prevalence. Obesity is associated with immune responses characterized by chronic systemic inflammation. This article focuses on the mechanisms that explain the proposed link between obesity-associated diseases and inflammation. Also, it describes the role of inflammatory molecules in obesity-associated metabolic abnormalities.

METHODS

More than 200 articles were selected and consulted by an online English search using various electronic search databases. Predefined key-words for the pathogenesis of obesity-induced inflammation and associated diseases, as well as the role of various inflammatory molecules, were used.

RESULTS

We have summarized the data of the articles consulted in this research and we have found that obesity is associated with a low-grade inflammation resulting from the change of adipose tissue (AT). The AT produces a variety of inflammatory molecules called adipocytokines that are involved in the onset of systemic low-grade inflammation which is the link between obesity and associated-chronic abnormalities; such as insulin resistance, metabolic syndrome, cardiovascular disease (CVD), hypertension, diabetes, and some cancers. Also, we have searched all the inflammatory molecules involved in this pathogenesis and we have briefly described the role of 16 of them which are the most related to obesity-associated inflammation. The results have shown that there are inflammatory molecules that have a positive relationship with the pathogenesis of obesity-related diseases and others have a negative relationship with this pathogenesis.

CONCLUSION

Inflammation plays a crucial role in the development of various metabolic-abnormalities related to obesity. In this regard, the management of obesity may help reduce the risk of cardiovascular disease and other metabolic complications by inhibiting inflammatory mechanisms.

Naringin inhibits colorectal cancer cell growth by repressing the PI3K/AKT/mTOR signaling pathway

In recent years, the incidence of colorectal cancer (CRC) has increased and research into new treatment methods for CRC has become a hot topic. Naringin has an inhibitory effect on the PI3k/AKT/mTOR signaling pathway in various tumor cell types and the effect of naringin is closely related to the occurrence and proliferation of tumor cells. The aim of this present study was to investigate whether naringin could inhibit the proliferation of CRC cells by inhibiting the PI3K/AKT/mTOR signaling pathway. This could provide a more mechanism-based treatment for CRC. MTT assays were used to detect the proliferation of CRC cells treated with various concentrations of naringin. The degree of apoptosis and the expression of apoptosis-related proteins (Bcl-2 and Bax) in CRC cells stimulated by naringin was detected using flow cytometry and western blot assays, respectively. The expression levels of PI3K/AKT/mTOR-related proteins [PI3K, AKT, mTOR, phosphorylated (p)-PI3K, p-AKT and p-mTOR] after naringin stimulation in CRC cells were detected using western blot assays. Naringin inhibited the proliferation of CRC cells in a dose-dependent manner. Naringin promoted the apoptosis of CRC cells and inhibited the activation of the PI3K/AKT/mTOR signaling pathway in a dose-dependent manner. The results demonstrated that naringin may be a promising therapeutic agent for the treatment of CRC, which may inhibit the proliferation of CRC cells and induce apoptosis by inhibiting the PI3K/AKT/mTOR signaling pathway.

Jejunal Insulin Signalling Is Increased in Morbidly Obese Subjects with High Insulin Resistance and Is Regulated by Insulin and Leptin

Little is known about the jejunal insulin signalling pathways in insulin resistance/diabetes states and their possible regulation by insulin/leptin. We study in jejunum the relation between insulin signalling and insulin resistance in morbidly obese subjects with low (MO-low-IR) or with high insulin resistance (MO-high-IR), and with type 2 diabetes treated with metformin (MO-metf-T2DM)), and the effect of insulin/leptin on intestinal epithelial cells (IEC). Insulin receptor substrate-1 (IRS1) and the catalytic p110β subunit (p110β) of phosphatidylinositol 3-kinase (PI3K) were higher in MO-high-IR than in MO-low-IR. The regulatory p85α subunit of PI3K (p85α)/p110β ratio was lower in MO-high-IR and MO-metf-T2DM than in MO-low-IR. Akt-phosphorylation in Ser473 was reduced in MO-high-IR compared with MO-low-IR. IRS1 and p110-β were associated with insulin and leptin levels. The improvement of body mass index (BMI) and HOMA-IR (homeostasis model assessment of insulin resistance index) after bariatric surgery was associated with a higher IRS1 and a lower p85α/p110β ratio. IEC (intestinal epithelial cells) incubation with a high glucose + insulin dose produced an increase of p85α and p110β. High dose of leptin produced an increase of IRS1, p85α and p110β. In conclusion, despite the existence of insulin resistance, the jejunal expression of genes involved in insulin signalling was increased in MO-high-IR. Their expressions were regulated mainly by leptin. IRS1 and p85α/p110β ratio was associated with the evolution of insulin resistance after bariatric surgery.

FTO - A Common Genetic Basis for Obesity and Cancer

In recent years, the prevalence of obesity and cancer have been rising. Since this poses a serious threat to human health, the relationship between the two has attracted much attention. This study examined whether fat mass and obesity-associated (FTO) genes are linked, taking into account a Genome-wide Association Study (GWAS) that revealed multiple single nucleotide polymorphism sites (SNPs) of the FTO gene, indicating an association between obesity and cancer in different populations. FTO proteins have been proved to participate in adipogenesis and tumorigenesis with post-transcriptional regulation of downstream molecular expression or through the target of the mammalian target protein rapamycin (mTOR). FTO inhibitors have also been found to share anti-obesity and anti-cancer effects in vivo. In this review, we comprehensively discuss the correlation between obesity and cancer by measuring FTO gene polymorphism, as well as the molecular mechanism involved in these diseases, emphasizing FTO as the common genetic basis of obesity and cancer.

Ghrelin inhibits cisplatin-induced MDA-MB-231 breast cancer cell apoptosis via PI3K/Akt/mTOR signaling

Ghrelin is a multi-functional peptide, its role on cancer cell apoptosis remains controversial. The present study examined the effects and mechanisms of ghrelin on cisplatin-induced apoptosis in human breast cancer cells. It was identified that ghrelin inhibited apoptosis in MDA-MB-231 cells in vitro and reversed the expression of B-cell lymphoma 2 (Bcl2) and Bcl2-associated X, and cleaved caspase-3 induced by cisplatin. Furthermore, ghrelin activated the phosphoinositide 3-kinases/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway after cisplatin treatment. The effects of ghrelin on the cisplatin-induced apoptosis and PI3K/Akt/mTOR signaling were reversed by the growth hormone secretagogue receptor small interfering RNA. The present study suggests that ghrelin may serve as a novel target for cisplatin resistance and a potential indicator of cisplatin sensitivity in breast cancer treatment.

LOXL1-AS1 Drives The Progression Of Gastric Cancer Via Regulating miR-142-5p/PIK3CA Axis

Background

Gastric cancer (GC) is a deadly disease, and its incidence is especially high in East Asia including China. Recently, some long non-coding RNA (lncRNAs) have been identified as oncogenes or tumor suppressors. This study aimed to determine the function and mechanism of lncRNA LOXL1-AS1 on the progression of GC.

Methods

RT-PCR was done to measure the expression levels of LOXL1-AS1 and miR-142-5p in GC tissues. The association between pathological indexes and LOXL1-AS1 expression was also analyzed. Human GC cell lines AGS and BGC823 were used as cell models. CCK-8 and colony formation assays were conducted to assess the effect of LOXL1-AS1 on the proliferation of GC cell lines. Transwell assay was conducted to determine the influence of LOXL1-AS1 on cell migration and invasion. Furthermore, luciferase reporter assay was carried out to confirm the relationship of miR-142-5p with LOXL1-AS1. Additionally, Western blot was done to detect the regulatory function of LOXL1-AS1 on PIK3CA, a target of miR-142-5p. In vivo experiment was also performed to validate the roles and mechanism of LOXL1-AS1 on the growth and metastasis of GC cells.

Results

LOXL1-AS1 expression in GC samples was significantly increased, which was correlated with unfavorable pathological indexes. Highly expressed LOXL1-AS1 was closely linked to shorter overall survival time and post-progression survival time of the patients. LOXL1-AS1 markedly modulated the malignant phenotypes of GC cells. Additionally, overexpressed LOXL1-AS1 notably reduced the expression of miR-142-5p, but enhanced the expression level of PIK3CA. In vivo experiments further validated that knockdown of LOXL1-AS1 inhibited the growth and metastasis of GC cells via regulating miR-142-5p and PIK3CA.

Conclusion

LOXL1-AS1 was a sponge of tumor suppressor miR-142-5p in GC, enhanced the expression of PIK3CA indirectly and functioned as an oncogenic lncRNA.

Insulin as an immunomodulatory hormone

Insulin plays an indispensable role in the management of hyperglycaemia that arises in a variety of settings, including Type I and II diabetes, gestational diabetes, as well as is in hyperglycaemia following a severe inflammatory insult. However, insulin receptors are also expressed on a range of cells that are not canonically implicated in glucose homeostasis. This includes immune cells, where the anti-inflammatory effects of insulin have been repeatedly reported. However, recent findings have also implicated a more involved role for insulin in shaping the immune response during an infection. This includes the ability of insulin to modulate immune cell differentiation and polarisation as well as the modulation of effector functions such as biocidal ROS production. Finally, inflammatory mediators can through both direct and indirect mechanisms also regulate serum insulin levels, suggesting that insulin may be co-opted by the immune system during an infection to direct immunological operations. Collectively, these observations implicate insulin as a bona fide immune-modulating hormone and suggest that a better understanding of insulin's immunological function may aid in optimising insulin therapy in a range of clinical settings.

Expression of leptin and leptin receptors in colorectal cancer-an immunohistochemical study

Obesity is demonstrated to be a risk factor in the development of cancers of various organs, such as colon, prostate, pancreas and so on. Leptine (LEP) is the most renowned of the adipokines. As a hormone, it mediates its effect through leptin receptor (LEPR), which is widely expressed in various tissues including colon mucosa. In this study, we have investigated the degree of expression of LEP and LEPR in colorectal cancer (CRC). We collected 44 surgically resected colon cancer tissues along with normal adjacent colon tissue (NACT) from a sample of CRC patients from the Malaysian population and looked for leptin and leptin receptors using immunohistochemistry (IHC). All the samples showed low presence of both LEP and LEPR in NACT, while both LEP and LEPR were present at high intensity in the cancerous tissues with 100% and 97.7% prevalence, respectively. Both were sparsed in the cytoplasm and were concentrated beneath the cell membrane. However, we did not find any significant correlation between their expression and pathological parameters like grade, tumor size, and lymph node involvement. Our study further emphasizes the possible causal role of LEP and LEPR with CRC, and also the prospect of using LEPR as a possible therapeutic target.

The influence of leptin on the process of carcinogenesis

Obesity is a new risk factor, to which more and more research is devoted, related to the development of cancer. Many studies of recent years have drawn attention to the role of adipose tissue as an important internal endocrine organ. In the adipose tissue proteins are produced, referred to by the common name as adipokines. In the case of obesity, the neoplasm cells are constantly stimulated by pro-inflammatory cytokines and adipokines, among which leptin dominates. The studies show that leptin can affect the cancer cells through numerous phenomena, e.g. inflammation, cell proliferation, suppression of apoptosis and angiogenesis. In this literature review we examined the role of leptin in the development of the individual cancers: breast cancer, colorectal cancer, prostate cancer, ovarian cancer, endometrial cancer and brain neoplasms: glioma and meningioma. However, leptin has very complicated mechanisms of action which require better understanding in certain types of cancer.

Icariin enhances the chemosensitivity of cisplatin‑resistant ovarian cancer cells by suppressing autophagy via activation of the AKT/mTOR/ATG5 pathway

Icariin is a flavonoid derived from Epimedium sagittatum, and has a wide range of biological and pharmacological effects; however, little is known regarding its effect on drug‑resistant ovarian cancer and the signal transduction pathways underlying the regulation of apoptosis and autophagy. The present study aimed to investigate the re‑sensitization effects of icariin exerted on an ovarian cancer cell line. Autophagy was analyzed in a SKVCR cell line that had been treated with icariin. We investigated the sensitivity of SKVCR cells to cisplatin, as well as the effects of an autophagy agonist (rapamycin) on autophagy, apoptosis, and the protein kinase B (AKT) signaling pathway. Finally, the mechanism underlying the effects of autophagy‑related (ATG) protein ATG5 overexpression on autophagy, apoptosis and AKT signaling in SKVCR cells were determined. The results revealed that treatment with icariin inhibited cell viability and autophagy, but promoted G0/G1 phase cell cycle arrest and apoptosis as determined by Cell Counting Kit‑8, immunofluorescence and flow cytometry assays, respectively. Icariin reduced the resistance of SKVCR cells to cisplatin in vitro by inducing G1/S cell cycle transition, apoptosis and inhibiting autophagy. Furthermore, enhanced autophagy induced by rapamycin treatment or overexpression of ATG5 partially reversed the effect of icariin on cisplatin resistance and autophagy in SKVCR cells. At the molecular level, rapamycin treatment or overexpression of ATG5 reversed the effects of icariin on the expression of autophagy‑associated proteins, including microtubule‑associated protein 1 light chain 3β, Beclin‑1, ATG5 and p62, and the AKT/mammalian target of rapamycin (mTOR) pathway. Collectively, our results suggested that icariin enhances the chemosensitivity of SKVCR cells by suppressing autophagy via activation of the AKT/mTOR signaling pathway.

Estrogen and insulin synergistically promote endometrial cancer progression via crosstalk between their receptor signaling pathways

Objective

Despite evidence that estrogens and insulin are involved in the development and progression of many cancers, their synergistic role in endometrial carcinoma (EC) has not been analyzed yet.

Methods

Here, we investigated how estrogens act synergistically with insulin to promote EC progression. Cell growth in vitro and in vivo, effects of estradiol and insulin on apoptosis and cell cycle distribution, and expression and activation of estrogen receptor (ER), insulin receptor (InsR), and key proteins in the PI3K and MAPK pathways were examined after combined stimulation with estradiol and insulin.

Results

Compared to EC cells treated with estradiol or insulin alone, those treated with both estradiol and insulin exhibited stronger stimulation. Estradiol significantly induced phosphorylation of InsR-β and IRS-1, whereas insulin significantly induced phosphorylation of ER-α. In addition, treatment with both insulin and estradiol together significantly increased the expression and phosphorylation of Akt, MAPK, and ERK. Notably, InsR-β inhibition had a limited effect on estradiol-dependent proliferation, cell cycle, and apoptosis, whereas ER-α inhibition had a limited insulin-dependent effect, in EC cell lines. Insulin and estradiol individually and synergistically promoted EC xenograft growth in mice.

Conclusions

Estrogen and insulin play synergistic roles in EC carcinogenesis and progression by activating InsR-β and ER-α, promoting a crosstalk between them, and thereby resulting in the activation of downstream PI3K/Akt and MAPK/ERK signaling pathways.

Activation of antioxidant defences of human mammary epithelial cells under leptin depend on neoplastic state

BACKGROUND

Obesity is associated with oxidative stress, a major factor in carcinogenesis, and with high leptin concentration. The aim of this study was to determine the effects of leptin on the antioxidant response in three human mammary epithelial cells each presenting a different neoplastic status: healthy human mammary epithelial cells (HMEC), oestrogen-receptor positive MCF-7 cells and triple-negative MDA-MB-231 cells.

METHODS

This in vitro kinetic study characterized the cell antioxidant response after 1, 6 and 24 h in the presence of leptin (10 or 100 ng/ml).The antioxidant response was defined in terms of cell glutathione content, gene expression and catalytic activity of antioxidant enzymes (i.e. glutathione peroxidase 1 (Gpx1), glutathione reductase (GR), glutathione S transferase (GST), heme-oxygenase 1 (HO-1) and cyclooxygenase-2 (COX-2)). Oxidative stress occurrence was assessed by lipid hydro peroxide (HPLIP) and isoprostane concentrations in culture media at 24 h.

RESULTS

At both concentrations used, leptin induced ROS production in all cell models, contributing to various antioxidant responses linked to neoplastic cell status. HMEC developed a highly inducible antioxidant response based on antioxidant enzyme activation and an increase in cell GSH content at 10 ng/ml of leptin. However, at 100 ng/ml of leptin, activation of antioxidant response was lower. Conversely, in tumour cells, MCF-7 and MDA-MB-231, leptin did not induce an efficient antioxidant response, at either concentration, resulting in an increase of lipid peroxidation products.

CONCLUSIONS

Leptin can modulate the oxidative status of mammary epithelial cells differently according to their neoplastic state. These novel results shed light on oxidative status changes in mammary cells in the presence of leptin.

The prognostic and therapeutic role of hormones in colorectal cancer: a review

Colorectal cancer (CRC) is one of the commonest cancers in Western society with a poor prognosis in patients with advanced disease. Targeted therapy is of increasing interest and already, targeted hormone treatment for breast and prostate cancer has improved survival. The aim of this literature review is to summarise the role of hormones in CRC prognosis and treatment. A literature review of all human and animal in vivo and in vitro studies in the last 20 years, which assessed the role of hormones in CRC treatment or prognosis, was carried out. The hormones described in this review have been subdivided according to their secretion origin. Most of the studies are based on in vitro or animal models. The main findings point to adipokines, insulin and the insulin growth factor axis as key players in the link between obesity, type 2 diabetes mellitus and a subset of CRC. Gut-derived hormones, especially uroguanylin and guanylin are being increasingly investigated as therapeutic targets, with promising results. Using hormones as prognostic and therapeutic markers in CRC is still in the preliminary stages for only a fraction of the hormones affecting the GIT. In light of the increasing interest in tailoring treatment strategies, hormones are an important area of focus in the future of CRC management.

UNBS5162 inhibits proliferation of human melanoma cells by inducing apoptosis via the PI3K/Akt pathway

UNBS5162, a novel naphthalimide, is generated by UNBS3157 hydrolysis in physiological saline. In the present study, the effects of UNBS5162 on M14 human melanoma cells were evaluated by Cell Counting Kit‑8 and transwell assays, as well as western blotting. The underlying mechanism of apoptosis induced by UNBS5162 was investigated. The results demonstrated that proliferation of UNBS5162‑treated M14 melanoma cells was markedly inhibited in a time‑dependent manner. The flow cytometry results indicated a markedly increased apoptosis rate in the experimental group compared with in the control group (23.8±0.4 vs. 7.62±0.5%). Microscopy analysis revealed that the invasive and migratory abilities of UNBS5162‑treated M14 cells were markedly suppressed. Furthermore, UNBS5162 treatment led to decreased expression of the anti‑apoptotic protein B‑cell lymphoma 2, but increased expression of the pro‑apoptotic proteins Bcl‑2‑associated X protein and caspase‑3. In addition, the expression of several key proteins involved in the phosphatidylinositol‑4,5‑bisphosphate 3‑kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathway was altered in M14 cells treated with UNBS5162. Based on these results, it may be hypothesized that UNBS5162 suppresses the proliferation of M14 cells by inducing apoptosis via inhibition of key proteins in the PI3K/Akt/mTOR signaling pathway.

Expression of leptin in colorectal adenocarcinoma showed significant different survival patterns associated with tumor size, lymphovascular invasion, distant metastasis, local recurrence, and relapse of disease in the western province of Saudi Arabia

Leptin phenotype has been suggested to be a possible biomarker for the diagnosis and prognosis of different neoplasms. Nonetheless, there are conflicts among the outcomes found in several tumors, and little is proven concerning the correlation between the phenotype of leptin and its clinical significance in colorectal carcinomas. This study will describe the phenotype of leptin in colorectal adenocarcinomas, and investigate its correlation with clinicopathological factors.Two hundred and twenty eight tissue samples include 155 colorectal carcinomas, 40 adenomas, and 33 noncancerous cases were utilized in constructing tissue microarrays which have been used in the revealing of leptin expression using leptin monoclonal antibody and immunohistochemistry staining protocol.Immunoexpression of leptin was recognized in 145 (93.5%) of colorectal tumors and 56 (76.7%) cases of control group. Histotype was considerably associated with leptin phenotype (P = .000), there is up regulation in leptin expression in colorectal carcinoma cases. Significantly higher proportion of negative leptin immunostaining cases were observed in tumors which have size more than 5 cm (P = .045). Whereas, significant different survival patterns were observed in positive cases regarding tumor size, lymphovascular invasion, distant metastasis, local recurrence and relapse of disease (P-values .046, .011, .000, .013, and .001, respectively). On the other hand, positive leptin staining colorectal tumors with size <5 cm, and with no distant metastases, local recurrence, or disease relapse had significantly better survival estimates. However, leptin immunostaining did not show noteworthy associations with age, gender, differentiation, tumor location, stage, margins involvement, lymphovascular invasion, and lymph node metastasis.The current study shows up regulation in leptin expression in colorectal adenocarcinoma compared with noncancerous control cases. Thus, immunohistochemical staining of leptin in colorectal cancer could be a helpful tool in the prediction of prognosis and survival pattern of colorectal cancer with certain clinicopathological factors (tumor size, lymphovascular invasion, distant metastasis, local recurrence, and relapse of disease).

Leptin Regulation of Cancer Stem Cells in Breast and Gynecologic Cancer

It is well established that obesity increases the incidence and worsens the prognosis of women's cancer. For breast cancer, women with obesity exhibit more than a twofold increase in the odds of being diagnosed with cancer, with a greater risk of advanced stage at diagnosis, and ≤40% greater risk of recurrence and death than their normal-weight counterparts. These findings are similar in gynecologic cancers, where women who are obese with a body mass index (BMI) >40 kg/m2 have up to six times greater risk of developing endometrial cancer and a 9.2% increase in mortality with every 10% increase in BMI. Likewise, patients with obesity exhibit a twofold higher risk of premenopausal ovarian cancer, and patients who are obese with advanced stage ovarian cancer have shown a shorter time to recurrence and poorer overall survival. Obesity is accompanied by changes in expression of adipose factors that act on local tissues and systemically. Once obesity was recognized as a factor in cancer incidence and progression, the adipose cytokine (adipokine) leptin became the focus of intense investigation as a putative link, with nearly 3000 publications on the topic. Leptin has been shown to increase cell proliferation, inhibit apoptosis, promote angiogenesis, and increase therapeutic resistance. These characteristics are associated with a subset of cells in both liquid and solid tumors known as cancer stem cells (CSCs), or tumor initiating cells. We will review the literature discussing leptin's role in breast and gynecologic cancer, focusing on its role in CSCs, and consider goals for targeting future therapy in this arena to disrupt tumor initiation and progression in women's cancer.

Underrated enemy - from nonalcoholic fatty liver disease to cancers of the gastrointestinal tract

Nonalcoholic fatty liver disease (NAFLD) is intrahepatic ectopic lipid deposition which is present despite a lack of other causes of secondary hepatic fat accumulation. It is the most common chronic liver disorder in the welldeveloped countries. NAFLD is a multidisciplinary disease that affects various systems and organs and is inextricably linked to simple obesity, metabolic syndrome, insulin resistance and overt diabetes mellitus type 2. The positive energy balance related to obesity leads to a variety of systemic changes including modified levels of insulin, insulin- like growth factor-1, adipokines, hepatokines and cytokines. It is strongly linked to carcinogenesis and new evidence proves that NAFLD is associated with higher risk of all-cause mortality and cancer-specific mortality among cancer survivors. This article focuses on the association between NAFLD and extrahepatic gastrointestinal tract cancers, aiming to shed light on the pathomechanism of changes leading to the development of tumors.

Leptin promotes the growth of breast cancer by upregulating the Wnt/β-catenin pathway

The present study aimed to investigate the role of leptin in the growth of breast cancer. In the present study, expression of leptin in tumor tissues and adjacent tissues was detected by reverse transcription-quantitative polymerase chain reaction. Serum leptin in patients with breast cancer and normal healthy controls was detected by ELISA. Different concentrations of leptin were used to treat breast cancer cells, and cell proliferation was detected by cell proliferation assay. Interactions between leptin and Wnt/β-catenin were evaluated by western blotting. It was demonstrated that expression of leptin mRNA was significantly higher in tumor tissues than in adjacent tissues in 43 out of 48 patients. Serum level of leptin was significantly higher in patients with breast cancer than in normal controls. Leptin promoted the proliferation of breast cancer cells in a dose-dependent manner. Leptin significantly increased the expression level of β-catenin in breast cancer cells. Treatment with Wnt inhibitor reduced the enhancing effects of leptin on proliferation of breast cancer cells. The results of the present study therefore indicate that leptin may promote the growth of breast cancer by upregulating the Wnt/β-catenin pathway.

Retracted Article: Salvianolic acid B inhibits inflammatory response and cell apoptosis via the PI3K/Akt signaling pathway in IL-1β-induced osteoarthritis chondrocytes

Osteoarthritis (OA) is the most common joint disease among late middle-aged or elderly people. The pathological process of OA mainly involves the degeneration of cartilage tissue and deficiency of joint function. Salvianolic acid B (Sal B) is the main active ingredient of Salvia miltiorrhiza Bge, which possesses anti-inflammatory, anti apoptotic and other pharmacological activities. In this study, primary chondrocytes were cultured to investigate the effects of Sal B on the inflammatory response and apoptosis of OA induced by IL-1β, and to explore the possible mechanism. First, we determined the cytotoxicity of Sal B; the results showed that the cell activity of chondrocytes was not influenced by Sal B when the concentration was below 150 μM. Moreover, Sal B (40 and 80 μM) suppressed the expression of iNOS in OA chondrocytes induced by IL-1β, and restrained the secretion of NO, IL-6, IL-17 and TNF-α in chondrocytes obviously. Sal B (40, 80 μM) significantly alleviated the inhibitory effect of cell activity stimulated by IL-1β and up-regulated the expression of Col II and reduced the expression of Col X. Besides, Sal B down-regulated the expression level of Bax and promoted the expression of Bcl-2, showed a significant effect on promoting proliferation and inhibiting cell apoptosis. In addition, we found that IL-1β significantly reduced the ratio of p-PI3K/PI3K, p-Akt/Akt induced the nuclear translocation of AKT and inhibited the activation of the PI3K/Akt signaling pathway. Finally, the PI3K inhibitor, LY-294002, was added in IL-1β-induced chondrocytes. The results suggest that Sal B ameliorates IL-1β induced inflammation and suppresses apoptosis in OA by activating the PI3K/Akt signaling pathway. Our study reveals the mechanism of Sal B acts on OA and may provide a basis for the treatment of OA with Sal B.

Osteoarthritis (OA) is the most common joint disease among late middle-aged or elderly people.

The potential role of leptin in tumor invasion and metastasis

The adipocyte-released hormone-like cytokine/adipokine leptin behaves differently in obesity compared to its functions in the normal healthy state. In obese individuals, elevated leptin levels act as a pro-inflammatory adipokine and are associated with certain types of cancers. Further, a growing body of evidence suggests that higher circulating leptin concentrations and/or elevated expression of leptin receptors (Ob-R) in tumors may be poor prognostic factors. Although the underlying pathological mechanisms of leptin's association with poor prognosis are not clear, leptin can impact the tumor microenvironment in several ways. For example, leptin is associated with a number of biological components that could lead to tumor cell invasion and distant metastasis. This includes interactions with carcinoma-associated fibroblasts, tumor promoting effects of infiltrating macrophages, activation of matrix metalloproteinases, transforming growth factor-β signaling, etc. Recent studies also have shown that leptin plays a role in the epithelial-mesenchymal transition, an important phenomenon for cancer cell migration and/or metastasis. Furthermore, leptin's potentiating effects on insulin-like growth factor-I, epidermal growth factor receptor and HER2/neu have been reported. Regarding unfavorable prognosis, leptin has been shown to influence both adenocarcinomas and squamous cell carcinomas. Features of poor prognosis such as tumor invasion, lymph node involvement and distant metastasis have been recorded in several cancer types with higher levels of leptin and/or Ob-R. This review will describe the current scenario in a precise manner. In general, obesity indicates poor prognosis in cancer patients.

Expression of the β3 subunit of Na+/K+-ATPase is increased in gastric cancer and regulates gastric cancer cell progression and prognosis via the PI3/AKT pathway

ATP1B3 encodes the β3 subunit of Na⁺/K⁺-ATPase and is located in the q22-23 region of chromosome 3. Na⁺/K⁺-ATPase participates in normal cellular activities but also plays a crucial role in carcinogenesis. In the present study, we found that expression of the β3 subunit of Na⁺/K⁺-ATPase was increased in human gastric cancer tissues compared with that in normal matched tissues and that this increased expression predicted a poor outcome. ATP1B3 expression was elevated at both the mRNA and protein levels in gastric cancer cell lines relative to those in a normal gastric epithelial cell line. Interestingly, ATP1B3 knockdown significantly inhibited cell proliferation, colony-formation ability, migration, and invasion and increased apoptosis in human gastric carcinoma cell lines. Additionally, knockdown induced cell cycle arrest at the G2/M phase. Furthermore, we demonstrated that ATP1B3 silencing decreased the expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT) and phosphorylated AKT (p-AKT), indicating that ATP1B3 regulates gastric cancer cell progression via the PI3K/AKT signalling pathway. Hence, the β3 subunit of Na⁺/K⁺-ATPase plays an essential role in the tumourigenesis of gastric cancer and may be a potential prognostic and therapeutic target for the treatment of gastric cancer.

Microbiota, Inflammation and Colorectal Cancer

Colorectal cancer, the fourth leading cause of cancer-related death worldwide, is a multifactorial disease involving genetic, environmental and lifestyle risk factors. In addition, increased evidence has established a role for the intestinal microbiota in the development of colorectal cancer. Indeed, changes in the intestinal microbiota composition in colorectal cancer patients compared to control subjects have been reported. Several bacterial species have been shown to exhibit the pro-inflammatory and pro-carcinogenic properties, which could consequently have an impact on colorectal carcinogenesis. This review will summarize the current knowledge about the potential links between the intestinal microbiota and colorectal cancer, with a focus on the pro-carcinogenic properties of bacterial microbiota such as induction of inflammation, the biosynthesis of genotoxins that interfere with cell cycle regulation and the production of toxic metabolites. Finally, we will describe the potential therapeutic strategies based on intestinal microbiota manipulation for colorectal cancer treatment.

Endoplasmic reticulum stress induces autophagy and apoptosis while inhibiting proliferation and drug resistance in multiple myeloma through the PI3K/Akt/mTOR signaling pathway

We investigated the effects of endoplasmic reticulum stress (ERS) on autophagy, proliferation, apoptosis, and drug resistance in multiple myeloma (MM). MM patients enrolled in our study (n = 268) were classified into sensitive and resistant groups based on chemotherapy efficacy, and their serum levels of β2-MG, albumin (ALB), lactic dehydrogenase (LDH), Ca²⁺ and hemoglobin were determined. In addition, human MM U266 and MOLP-2/R cells were divided into blank, tunicamycin (TM), TM + insulin-like growth factor-1 (IGF-1), and TM + rapamycin groups, and measured expression of ERS-related, PI3K/Akt/mTOR pathway-related, and autophagy-related mRNA and proteins. Serum levels of β2-MG, LDH and Ca2⁺, and expression of PI3K, Akt, and mTOR were higher in the resistant than sensitive group. Serum levels of ALB and hemoglobin, and expression of glucose-regulated protein 78 (GRP78), GRP94, microtubule associated protein 1 light chain 3 (LC3), and Beclin1, were lower in the resistant than sensitive group. In U266 cells treated with TM and IGF-1 or rapamycin, ERS promoted autophagy and apoptosis while inhibiting proliferation through inhibition of PI3K/Akt/mTOR signaling. ERS also reversed drug resistance in MOLP-2/R cells via the PI3K/Akt/mTOR signaling pathway. These data suggest that ERS activation could be exploited for therapeutic benefits in the treatment of MM.

Emerging Role of MicroRNAs in mTOR Signaling

Mechanistic target of rapamycin (mTOR) is a conserved serine/threonine kinase that plays a critical role in the control of cellular growth and metabolism. Hyperactivation of mTOR pathway is common in human cancers, driving uncontrolled proliferation. MicroRNA (miRNA) is a class of short noncoding RNAs that regulate the expression of a wide variety of genes. Deregulation of miRNAs is a hallmark of cancer. Recent studies have revealed interplays between miRNAs and the mTOR pathway during cancer development. Such interactions appear to provide a fine-tuning of various cellular functions and contribute qualitatively to the behavior of cancer. Here we provide an overview of current knowledge regarding the reciprocal relationship between miRNAs and mTOR pathway: regulation of mTOR signaling by miRNAs and control of miRNA biogenesis by mTOR. Further research in this area may prove important for the diagnosis and therapy of human cancer.

Analysis of circulating adipokines in patients newly diagnosed with solid cancer: Associations with measures of adiposity and tumor characteristics

The development and progression of cancer is a complex and multifactorial process and the global prevalence of obesity is markedly increasing. A number of studies have made an association between obesity and increased rates of epithelial tumors. Obesity is associated with altered adipokine levels, potentially contributing to the process of tumor development and metastasis. In the current study, the associations between circulating adipokines and measures of adiposity and tumor characteristics among patients diagnosed with solid malignancies were examined at the time of presentation, and following the administration of chemotherapy. A total of 30 patients with cancer and matched healthy controls were enrolled in the present study. Plasma adipokine levels of hepatocyte growth factor (HGF), adiponectin and leptin were determined using commercially available ELISA kits. At baseline, plasma HGF, adiponectin and leptin levels were not significantly different between patients with cancer and the healthy controls. Circulating HGF levels were significantly associated with the stage of cancer at diagnosis (P=0.044), but lacked a significant association with lymph node status (P=0.194). Plasma adiponectin and leptin levels were not significantly associated with tumor characteristics at the time of diagnosis. Only leptin was positively correlated with the body mass index of patients with cancer (P<0.001). No significant correlations were detected between the evaluated adipokines and measures of visceral obesity, as determined by waist circumference and the waist-hip ratio at presentation. Following administration of chemotherapy, adiponectin was the only adipokine evaluated in the current study that exhibited a significant difference, when compared with baseline plasma levels (P=0.013), and a significant positive correlation between baseline and follow-up circulating levels (P=0.002) among patients with cancer. In addition, there were no significant inter-correlations between circulating adipokines at baseline level and during follow-up in patients with cancer. Collectively, the findings of the current study suggest a lack of diagnostic roles for the adipokines investigated and no significant association with measures of adiposity. Adiponectin may be a potential adipokine to measure in patients with cancer, in order to further assess its prognostic and predictive potential.

Alteration of Leptin and Adiponectin in Multistep Colorectal Tumorigenesis

BACKGROUND

There is an established link between obesity related metabolic derangement and colorectal cancer development. Recently, we developed a metabolic-colorectal cancer risk score. In this follow-up study, we studied its association with colorectal neoplasm by measuring two major metabolic syndrome biomarkers, leptin and adiponectin.

OBJECTIVES

To evaluate the serum levels of leptin and adiponectin in patients with colorectal polyps and colorectal cancer and to determine any correlation with metabolic risk score.

RESULTS

In total, 130 individuals were studied: 30 controls without colonic pathology, 18 with colonic adenoma (CAP), and 82 with colorectal adenocarcinoma (CRC, 17 cases of T1-2 and 65 cases of T3-4). The metabolic risk scores in CAP and T1-2 CRC were higher than those in the controls and T3-4 CRC cases. There were no statistically significant differences in leptin levels among CAPs, CRCs, and controls. Both leptin and adiponectin levels reflected differences in body mass index and metabolic risk scores. Cases in the CAP group and early T-stage CRC groups had lower adiponectin levels (14.03 and 13.01 mg/ml, respectively) than the no polyps group (19.5mg/ml, p = 0.03). The average serum adiponectin level in the invasive cancer group (18.5 ng/ml) was comparable with that of the control group.

CONCLUSIONS

The level of serum adiponectin was positively correlated with the metabolic risk score. Decreased serum adiponectin was significantly associated with the development of colorectal adenoma and early stage colorectal carcinoma.

Diets link metabolic syndrome and colorectal cancer development (Review)

Diets have been believed to be an important factor in the development of metabolic syndrome and colorectal cancer (CRC). In recent years, many studies have shown an intimate relationship between mucosal immunity, metabolism and diets, which has led to a greater understanding of the pathophysiology of metabolic syndrome and CRC development. Although the precise effects of diets on oncogenesis have not been compl-etely elucidated, microbiota changes and inflammation are believed to be important factors that influence the development of CRC. Moreover, increased release of pro-inflammatory cytokines and alteration of adipokine levels have been observed in patients with colorectal adenoma and/or CRC, and these all have been considered as the important mechanisms that link diets to the development of metabolic syndrome and CRC. Importantly, a high-fat, low-fiber diet is associated with dysbiosis, and as the gut signature becomes more important in metabolic syndrome and CRC, an increased understanding of diets on bacterial activity in the pathogenesis of metabolic syndrome and CRC will lead to new preventive and therapeutic strategies.