Aims/hypothesis Liraglutide is a glucagon-like peptide-1 (GLP-1) analogue that has been demonstrated to successfully treat diabetes and promote weight loss. The mechanisms by which liraglutide confers weight loss remain to be fully clarified. Thus, we investigated whether GLP-1 receptors are expressed in human brains and whether liraglutide administration affects neural responses to food cues in diabetic individuals (primary outcome). Methods In 22 consecutively studied human brains, expression of GLP-1 receptors in the hypothalamus, medulla oblongata and parietal cortex was examined using immunohistochemistry. In a randomised (assigned by the pharmacy using a randomisation enrollment table), placebo-controlled, double-blind, crossover trial, 21 individuals with type 2 diabetes (18 included in analysis due to lack or poor quality of data) were treated with placebo and liraglutide for a total of 17 days each (0.6 mg for 7 days, 1.2 mg for 7 days and 1.8 mg for 3 days). Participants were eligible if they had type 2 diabetes and were currently being treated with lifestyle changes or metformin. Participants, caregivers, people doing measurements and/or examinations, and people assessing the outcomes were blinded to the medication assignment. We studied metabolic changes as well as neurocognitive and neuroimaging (fMRI) of responses to food cues at the clinical research centre of Beth Israel Deaconess Medical Center. Results Immunohistochemical analysis revealed the presence of GLP-1 receptors on neurons in the human hypothalamus, medulla and parietal cortex. Liraglutide decreased activation of the parietal cortex in response to highly desirable (vs less desirable) food images (p < 0.001; effect size: placebo 0.53 ± 0.24, liraglutide −0.47 ± 0.18). No significant adverse effects were noted. In a secondary analysis, we observed decreased activation in the insula and putamen, areas involved in the reward system. Furthermore, we showed that increased ratings of hunger and appetite correlated with increased brain activation in response to highly desirable food cues while on liraglutide, while ratings of nausea correlated with decreased brain activation. Conclusions/interpretation For the first time, we demonstrate the presence of GLP-1 receptors in human brains. We also observe that liraglutide alters brain activity related to highly desirable food cues. Our data point to a central mechanism contributing to, or underlying, the effects of liraglutide on metabolism and weight loss. Future studies will be needed to confirm and extend these findings in larger samples of diabetic individuals and/or with the higher doses of liraglutide (3 mg) recently approved for obesity.
Obesity and insulin resistance have been implicated in the etiology of pancreatic cancer (PC). Whether adiponectin and/or leptin, two adipocyte-secreted hormones important in metabolic regulation, are associated with PC pathogenesis and whether adiponectin receptors are expressed in PC remains unknown. In a hospital-based case-control study, we studied 81 cases with incident, histologically confirmed PC and 81 controls matched on gender and age between 2000 and 2007 to investigate the role of adiponectin and leptin adjusting for risk factors linked to PC. In a separate study, we also studied for the first time whether adiponectin receptors 1 and 2 are expressed in PC by studying 16 PC tumor tissue samples which were analyzed using immunohistochemistry. When subjects were divided into control-defined quartiles of adiponectin and leptin, lower leptin but higher adiponectin levels were associated with PC (p=0.001 and p=0.05 respectively) before and after controlling for age, gender, BMI, smoking status, alcohol consumption, history of diabetes, and family history of pancreatic cancer. Of the PC tumor tissue samples analyzed, 87.5% had positive or strong positive expression of AdipoR1 and 93.7% had positive or strong positive expression of AdipoR2. Further prospective studies are needed to determine whether the elevated adiponectin and low leptin levels reported in this study reflect compensatory changes during PC progression and thus can be used as markers for PC or whether they are causally implicated in PC.
These data provide both insights into the molecular mechanisms of antitumor activity of proteasome inhibitors and the rationale for future clinical trials of bortezomib, alone or in combination with conventional chemotherapy, to improve patient outcome in medullary and anaplastic thyroid carcinomas.
Circulating adiponectin is independently and inversely associated with the risk of thyroid cancer. Human thyroid carcinomas and cell lines express adiponectin receptors. However, in the absence of a major direct effect of adiponectin on thyroid cancer cell lines in vitro, the negative association observed herein may be attributed to the metabolic effects of adiponectin.
Background: Decreased circulating levels of adiponectin, an adipocyte-secreted hormone and endogenous insulin sensitizer, have been associated with several obesity-related malignancies. Thiazolidinedione administration, which increases adiponectin levels, decreases risk for lung cancer. Whether circulating adiponectin levels are associated with lung cancer and/or whether adiponectin receptors are expressed in lung cancer remains unknown. Methods: We conducted a case-control study of 85 patients with incidental, histologically confirmed lung cancer and 170 healthy controls matched by gender and age. In a separate study, archival lung specimens from 134 cancerous and 8 noncancerous tissues were examined for relative expression of adiponectin receptors AdipoR1 and AdipoR2 using immunohistochemistry. Results: Tobacco smoking, heavy alcohol intake and education were all associated with lung cancer risk, whereas serum adiponectin levels were not significantly different between cases and controls (multiple logistic regression, odds ratio per SD of adiponectin among controls: 1.13, 95% confidence interval: 0.64–2.02). Adiponectin levels were significantly lower (odds ratio: 0.25, 95% confidence interval: 0.10–0.78) among patients with advanced compared to those with limited disease stage. Expression of adiponectin receptors was apparent only in the cancerous lung tissue (64.2% AdipoR1 and 61.9% AdipoR2 in cancerous vs. 0% among noncancerous tissue). Specifically, AdipoR1 was expressed in all disease types, but no difference was noted with disease stage, whereas AdipoR2 was mainly expressed in the non-small cell carcinomas and more prominently in the advanced disease stage (80%). Conclusions: Circulating adiponectin levels are not different in cases of this malignancy – which seems to be unrelated to obesity and insulin resistance – compared to their healthy controls, though hormonal levels were significantly lower in advanced versus limited lung cancer. Both adiponectin receptors were expressed in cancerous lung tissue, but not in normal control tissue and there was a differential expression by disease stage. These findings should be further explored, especially in the context of the recently reported protective effect of thiazolidinediones in diabetic patients with lung cancer.
Objective To investigate the potential association of neutrophil-to-lymphocyte ratio (NLR), a surrogate systemic inflammatory biomarker, with clinical and pathological characteristics of papillary thyroid cancers. Methods 205 patients with papillary carcinoma were identified from the institutional thyroid cancer database between 2006 and 2015 (55 males, 150 females, mean age 51.2 ± 14.7 years). NLR was calculated as the absolute neutrophil count divided by the absolute lymphocyte count, based on the preoperative complete blood cell counts. Results NLR was significantly higher in carcinomas with extrathyroidal invasion (2.74 ± 01.24 versus 2.39 ± 0.96, p = 0.04) and bilateral (2.67 ± 1.15 versus 2.35 ± 0.96, p = 0.03) and multifocal tumours (2.65 ± 1.08 versus 2.29 ± 0.96, p = 0.01), as well as lymph node-positive tumours (3.12 ± 1.07 versus 2.41 ± 1.02, p = 0.03). On the other hand, NLR values were not associated with gender, age, tumour size, histologic subtype, the presence of thyroiditis, and TNM staging. Conclusions As an index of inflammation, NLR is inexpensive, readily available, and easy to extract from routine blood tests. We found increased NLR values in papillary carcinomas with poorer histopathological profile and more aggressive clinical behaviour. Whether this systemic inflammatory response, as expressed by the NLR, represents the inflammatory microenvironment leading to tumourigenesis, or is a tumour-associated phenomenon, remains to be elucidated and warrants further study.
Low adiponectin levels are an independent risk factor for, and mediate the effect of obesity on endometrial cancer in epidemiology studies. The direct or indirect mechanisms underlying these findings remain to be elucidated. We first examined the expression of adiponectin receptor 1 (AdipoR1) and 2 (AdipoR2) in normal human endometrium and in endometrial cancer tissues ex vivo. We then utilized KLE and RL95-2 human endometrial cancer cell lines in vitro to study relative expression of AdipoRs, to investigate the effect of adiponectin on activating intracellular signaling pathways, and to assess its potential to alter malignant properties. We report for the first time that the relative expression level of AdipoR1 is higher than AdipoR2 in human endometrial cancer tissue but the expression of AdipoRs is not statistically different from non-neoplastic tissues. We also demonstrate for the first time in endometrial cancer cell lines in vitro that adiponectin suppresses endometrial cancer proliferation acting through AdipoRs. Adiponectin also increases the expression of the adaptor molecule LKB1 which is required for adiponectin-mediated activation of AMPK/S6 axis and modulation of cell proliferation, colony formation, adhesion and invasion of KLE and RL95-2 cell lines. These novel mechanistic studies provide for the first time in vitro and ex vivo evidence for a causal role of adiponectin in endometrial cancer.
Our findings showed that the use of IONM decreased significantly both temporary and permanent RLN injuries. The technology of IONM is safe and reliable, and this technique is an important adjunct in nerve dissection and functional neural integrity. The routine use of IONM reduced pitfalls and provided guidance for our surgeons in difficult cases, reoperations, and high-risk patients.
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