Plasma Leptin, hTERT Gene Expression, and Anthropometric Measures in Obese and Non-Obese Women with Breast Cancer

Obesity: a perfect storm for carcinogenesis

Obesity-related cancers account for 40% of the cancer cases observed in the USA and obesity is overtaking smoking as the most widespread modifiable risk factor for carcinogenesis. Here, we use the hallmarks of cancer framework to delineate how obesity might influence the carcinogenic hallmarks in somatic cells. We discuss the effects of obesity on (a) sustaining proliferative signaling; (b) evading growth suppressors; (c) resisting cell death; (d) enabling replicative immortality; (e) inducing angiogenesis; (f) activating invasion and metastasis; (g) reprogramming energy metabolism; and (h) avoiding immune destruction, together with its effects on genome instability and tumour-promoting inflammation. We present the current understanding and controversies in this evolving field, and highlight some areas in need of further cross-disciplinary focus. For instance, the relative importance of the many potentially causative obesity-related factors is unclear for each type of malignancy. Even within a single tumour type, it is currently unknown whether one obesity-related factor consistently plays a predominant role, or if this varies between patients or, even in a single patient with time. Clarifying how the hallmarks are affected by obesity may lead to novel prevention and treatment strategies for the increasingly obese population.

Co-Delivery of Curcumin and Chrysin by Polymeric Nanoparticles Inhibit Synergistically Growth and hTERT Gene Expression in Human Colorectal Cancer Cells

Nanoparticle (NP)-based combinational chemotherapy has been proposed as a potent approach for improving intracellular drug concentrations and attaining synergistic effects in colorectal cancer therapy. Here, two well-known herbal substances, Curcumin (Cur) and Chrysin (Chr), were co-encapsulated in PEGylated PLGA NPs and investigated their synergistic inhibitory effect against Caco-2 cancer cells. Characterization of nanoformulated drugs was determined using DLS, FTIR, TEM, and SEM. Drug release study was performed using dialysis method. MTT and real-time PCR assays were applied to evaluate the cytotoxic effects of free and nano-encapsulated drugs on expression level of hTERT in Caco-2 cells. The results showed that free drugs and nano-formulations exhibited a dose-dependent cytotoxicity against Caco-2 cells and especially, Cur-Chr-PLGA/PEG NPs had more synergistic antiproliferative effect and significantly arrested the growth of cancer cells than the other groups (P < 0.05). Real-time PCR results revealed that Cur, Chr, and combination of Cur-Chr in free and encapsulated forms inhibited hTERT gene expression. Also, it was found that Cur-Chr-PLGA/PEG NPs than free combination forms could further decline hTERT expression in all concentration (P < 0.05). In summary, our study represents the first report of nano-combinational application of the natural herbal substances with a one-step fabricated codelivery system for effective colorectal cancer combinational chemotherapy.

Nano-encapsulated metformin-curcumin in PLGA/PEG inhibits synergistically growth and hTERT gene expression in human breast cancer cells

The study was aimed at investigating the synergistic inhibitory effect of unique combinational regimen of nanocapsulated Metformin (Met) and Curcumin (Cur) against T47D breast cancer cells. For this purpose, Met and Cur were co-encapsulated in PEGylated PLGA nanoparticles (NPs) and evaluated for their therapeutic efficacy. The morphology and dynamic light scattering (DLS) analyses were carried out to optimize the nanoformulations. Drug release study was performed using dialysis method and then the cytotoxic and inhibitory effect of individual and combined drugs on expression level of hTERT in T47D breast cell line were evaluated using MTT assay and qPCR, respectively. The results showed that free drugs and formulations exhibited a dose-dependent cytotoxicity against T47D cells and especially, Met-Cur-PLGA/PEG NPs had more synergistic antiproliferative effect and significantly arrested the growth of cancer cells than the other groups (p < .05). Real-time PCR results revealed that Cur, Met and combination of Met-Cur in free and encapsulated forms inhibited hTERT gene expression. It was found that Met-Cur-PLGA/PEG NPs in relative to free combination could further decline hTERT expression in all concentration (p < .05). Taken together, our study demonstrated that Met-Cur-PLGA/PEG NPs based combinational therapy holds promising potential towards the treatment of breast cancer.

Specific TaqMan allelic discrimination assay for rs1477196 and rs9939609 single nucleotide polymorphisms of FTO gene demonstrated that there is no association between these SNPs and risk of breast cancer in Iranian women

Background:

Breast cancer (BC), is the most common cancer in women, that is the major cause of cancer-related morbidity and mortality in women. Obesity is considered as a major risk factor for BC that increases both the rate and intensity of the disease. Polymorphisms in FTO gene, a known obesity related gene, is shown to be associated with obesity-related traits as well. The aim of this study was to evaluate the association between previously reported single nucleotide polymorphisms (SNPs) of intron 1of FTO gene, rs1477196 and rs9939609 and risk of BC in a subset of Iranian BC patients.

Materials and Methods:

We genotyped 99 cases and 100 controls for the two SNPs of rs9939609 and rs1477196 by TaqMan allelic discrimination assay. For each sample in an allelic discrimination assay, a unique pair of fluorescent dye probe is used. One fluorescent dye probe has a perfect match with the wild type allele and the other fluorescent dye probe is perfectly matched to the mutated allele.

Results:

Our research has shown that the observed differences between case and control groups in the studied SNPs of FTO gene are not statistically significant (P > 0.05).

Conclusions:

Our findings suggest that there is no association between rs9939609 and rs1477196 polymorphisms in FTO gene and increase in risk of BC in the studied Iranian population. These results were inconsistent with that of previously reported case–control studies with BC that means presence of these polymorphisms depends on ethnic group.

Association of serum soluble leptin receptor and leptin levels with breast cancer

BACKGROUND

Leptin plays a key role in the regulation of energy expenditure and is known to circulate in both free and bound forms. Soluble leptin receptor (sOB-R) is a unique circulating form of leptin receptor that can bind to leptin. Leptin and leptin receptor have been implicated in processes leading to breast cancer initiation and progression. Our study was aimed to investigate the relationship between serum levels of sOB-R and leptin with breast cancer.

MATERIALS AND METHODS

Serum leptin and sOB-R levels were measured by enzyme-linked immunosorbent assay in 100 women with breast cancer cases compared with 100 age and body mass index (BMI)-matched controls without cancer. Lipid profiles were measured by enzymatic method.

RESULTS

The median serum levels of sOB-R in controls were significantly higher than that in breast cancer cases (odds ratio [OR], 1.98; 95% confidence interval [CI] = 0.77-188.2) versus (OR, 0.140; 95% CI = 0.09-98.1). Conversely, the median serum level of leptin in breast cancer cases was significantly higher than that in controls (OR, 67.90; 95% CI = 2.77-129.9) vs. (OR, 28.30; 95% CI = 0.60-113.1). Breast cancer was significantly associated with higher serum level of leptin (OR = 1.027, 95% CI = 1.017-1.038). Conversely, breast cancer was correlated with lower serum level of sOB-R (OR = 0.983, 95% CI = 0.969-0.997). Moreover, free leptin index (FLI) (leptin/sOB-R ratio) was associated with breast cancer (OR = 1.028, 95% CI = 1.015-1.042). The serum sOB-R level was negatively associated with leptin, BMI, and high density lipoprotein (r = -0.238, -0.186, and -0.168, respectively).

CONCLUSION

Our results suggested that FLI and serum leptin level rather than serum level of sOB-R was associated with the breast cancer.

Adiponectin and leptin molecular actions and clinical significance in breast cancer

Obesity is an important public health problem and major risk factor for postmenopausal breast cancer. Adipose tissue is the major component involved in the control of the metabolism through energy homeostasis, adipocyte differentiation, insulin sensitivity and the activation of anti-inflammatory metabolic and immune pathways. Leptin and Adiponectin pathways are involved in proliferation process in breast cancer. Current review describes potential relationship between the molecular actions and clinical significance of leptin and adiponectin in breast cancer.

The tetrad BMI, leptin, leptin/adiponectin (L/A) ratio and CA 15-3 are reliable biomarkers of breast cancer

BACKGROUND

Several studies have reported that leptin levels, the leptin/adiponectin (L/A) ratio and carbohydrate antigen (CA) 15-3 are especially elevated in breast cancer patients with high body mass index (BMI). The purpose of this study was to evaluate BMI, leptin, L/A ratio and CA 15-3 all together as reliable biomarkers for breast cancer.

METHODS

Serum levels of leptin, adiponectin and CA 15-3, as well as anthropometric and biochemical parameters were analysed in 88 female patients who participated in a mammography study. Predictive values of BMI, leptin, L/A ratio and CA 15-3 were determined with a 95% confidence interval.

RESULTS

Women were diagnosed with either breast cancer (n = 40) or benign breast lesions (n = 48). Among anthropometric parameters, age (P ≤ 0.001), weight (P ≤ 0.05) and waist circumference (P ≤ 0.02) were higher in patients with breast cancer than in patients without this pathology. The 75th percentile values for BMI, leptin, L/A ratio and CA 15-3 were 29.24 kg/m(2), 26.65 ng/ml, 2.37 and 18.45 IU, respectively. The suggested odds ratio for breast cancer patients with the values that were above the 75th percentile of the tetrad was 6.7 (0.7505-60.0665 confidence interval).

CONCLUSION

When the four variables were analysed together, a sensitivity of 83.3%, specificity of 80%, positive predictive value of 83.3% and negative predictive value of 80% were obtained. Results indicate that using the 75th percentile set points for BMI, leptin, L/A ratio and CA 15-3 together could offer a reliable approach to determine which women are at high risk for developing breast cancer.

Connection between telomerase activity in PBMC and markers of inflammation and endothelial dysfunction in patients with metabolic syndrome

Metabolic syndrome (MS) is a constellation of metabolic derangements associated with vascular endothelial dysfunction and oxidative stress and is widely regarded as an inflammatory condition, accompanied by an increased risk for cardiovascular disease. The present study tried to investigate the implications of telomerase activity with inflammation and impaired endothelial function in patients with metabolic syndrome. Telomerase activity in circulating peripheral blood mononuclear cells (PBMC), TNF-α, IL-6 and ADMA were monitored in 39 patients with MS and 20 age and sex-matched healthy volunteers. Telomerase activity in PBMC, TNF-α, IL-6 and ADMA were all significantly elevated in patients with MS compared to healthy volunteers. PBMC telomerase was negatively correlated with HDL and positively correlated with ADMA, while no association between TNF-α and IL-6 was observed. IL-6 was increasing with increasing systolic pressure both in the patients with MS and in the healthy volunteers, while smoking and diabetes were positively correlated with IL-6 only in the patients' group. In conclusion, in patients with MS characterised by a strong dyslipidemic profile and low diabetes prevalence, significant telomerase activity was detected in circulating PBMC, along with elevated markers of inflammation and endothelial dysfunction. These findings suggest a prolonged activity of inflammatory cells in the studied state of this metabolic disorder that could represent a contributory pathway in the pathogenesis of atherosclerosis.

The two major epidemics of the twenty-first century: obesity and cancer

It is a well-known fact that severe obesity is associated with the metabolic syndrome, type 2 diabetes, cardiovascular disease, hypertension, and other diseases. Epidemiological studies have suggested that obesity is also associated with increased risk of several cancer types. The number of people who are suffering from severe obesity is growing, and clinical data suggest that severely obese patients belong to a unique population with regards to risk, efficacy of screening, and cancer treatment. This review will point out the potential mechanism linking obesity and cancer and will discuss several challenges in various treatment modalities of cancer in obese patients.

Regulation of the human catalytic subunit of telomerase (hTERT)

Over the past decade, there has been much interest in the regulation of telomerase, the enzyme responsible for maintaining the integrity of chromosomal ends, and its crucial role in cellular immortalization, tumorigenesis, and the progression of cancer. Telomerase activity is characterized by the expression of the telomerase reverse transcriptase (TERT) gene, suggesting that TERT serves as the major limiting agent for telomerase activity. Recent discoveries have led to characterization of various interactants that aid in the regulation of human TERT (hTERT), including numerous transcription factors; further supporting the pivotal role that transcription plays in both the expression and repression of telomerase. Several studies have suggested that epigenetic modulation of the hTERT core promoter region may provide an additional level of regulation. Although these studies have provided essential information on the regulation of hTERT, there has been ambiguity of the role of methylation within the core promoter region and the subsequent binding of various activating and repressive agents. As a result, we found it necessary to consolidate and summarize these recent developments and elucidate these discrepancies. In this review, we focus on the co-regulation of hTERT via transcriptional regulation, the presence or absence of various activators and repressors, as well as the epigenetic pathways of DNA methylation and histone modifications.