GLP2-GLP2R signal affects the viability and EGFR-TKIs sensitivity of PC9 and HCC827 cells.

BACKGROUND: The resistance to epidermal growth factor receptor (EGFR)- tyrosine kinase inhibitors (TKIs) therapy is currently the major clinical challenge in the treatment of lung cancer. This study aims to reveal the role of glucagon-like peptide (GLP) 2 and GLP-2 receptor (GLP2R) signaling on the EGFR-TKIs and cisplatin resistance of lung cancer cells. METHODS: The common differentially expressed genes in PC9 and HCC827 cells that were individually resistant to one of the three EGFR-TKIs (dacomitinib, osimertinib and afatinib) were screened. The data were from GSE168043 and GSE163913. The expression of GLP2R in drug-resistant cells was detected by western blot. The effect of GLP2R expression down- or up-regulation on resistance to dacomitinib, osimertinib, afatinib or cisplatin was measured by CCK-8 and flow cytometry assays. The long-acting analog of GLP-2, teduglutide, treated the parental cells. RESULTS: A total of 143 common differentially expressed genes were identified. Compared with the parent cells, the GLP2R expression in drug-resistant cell lines was significantly up-regulated. The exogenous expression of GLP2R in parental cells enhanced cell viability, while knockdown of GLP2R levels in drug-resistant cell lines inhibited cell viability. In addition, teduglutide treatment also enhanced the viability of lung cancer cells. CONCLUSION: GLP2-GLP2R signal may change the sensitivity of cells to EGFR-TKIs and cisplatin. The development of GLP-2 or GLP2R inhibitors may be beneficial to the clinical treatment of lung cancer.

Probiotics have minimal effects on appetite-related hormones in overweight or obese individuals: A systematic review of randomized controlled trials.

BACKGROUND & AIMS: Overweight and obese individuals show changes in mechanisms related to appetite due to several factors, including excess fat and gut microbiota imbalance. Probiotics have been presented as a strategy for modulating gut microbiota and regulating these mechanisms. The aim of this systematic review was to assess the effects of probiotics on appetite-related hormones in overweight or obese individuals. METHODS: A systematic review of randomized controlled trials was performed in nine electronic databases (Pubmed, Scopus, Web of Science, Cochrane Controlled Register of Trials, ProQuest Dissertations and Theses, PsycINFO, WHO International Clinical Trials Registry Platform, ClinicalTrials.gov and Open Grey) and in a manual search of studies until March 20, 2020. The risk of bias of each study was appraised using the RoB 2.0 tool. All research stages were carefully based on PRISMA recommendations. RESULTS: Twenty-four studies (1587 participants) were included in this systematic review. The outcomes related to appetite assessed in the included studies were: leptin, insulin, adiponectin, resistin, nesfatin-1, adropin, omentin-1, GLP-1, GLP-2 and glucagon. Compared to the control group after supplementation, four studies involving 272 participants reported statistically significant reduction in fasting insulin. On the other hand, one study involving 56 participants reported statistically significant increase in adropin and omentin-1. CONCLUSIONS: Probiotics have minimal effects on appetite-related hormones in overweight or obese individuals. However, knowledge in this area is progressing and further studies with a low risk of bias may help to clarify the role of probiotics in appetite control.

Linagliptin: a novel xanthine-based dipeptidyl peptidase-4 inhibitor for treatment of type II diabetes mellitus.

Type 2 diabetes mellitus causes significant morbidity and mortality on account of its progressive nature and results in considerable burden on healthcare resources. Current treatment strategies have only limited long-term efficacy and tolerability given the progressive nature of the disease leading to inadequate glycemic control and are also associated with undesirable side effects such as weight gain, hypoglycemia and gastrointestinal distress. In the light of these existing limitations, exploring new treatment targets and new therapies have become the need of the hour at present. The incretin pathway, in particular, glucagon-like peptide (GLP-1), plays an important pathological role in the development of type 2 diabetes mellitus, and treatments targeting the incretin system have recently generated surmount interest. These can mainly be categorized into two broad classes; GLP-1 agonists/analogs (exenatide, liraglutide), and dipeptidyl peptidase- 4 inhibitors (sitagliptin, vildagliptin). The gliptins act by prolonging the action of incretins, the gut hormones which can boost insulin levels. Linagliptin is the latest dipeptidyl peptidase-4 inhibitor to complete pivotal phase III trials, which have demonstrated its superiority to its competitors based on its low therapeutic dose, long-lasting inhibition of DPP-4 activity and a good safety/tolerability profile. One of the unique characteristics of linagliptin is its primarily non-renal route of excretion. The drug has recently been approved by the US Food and Drug Administration and has been portrayed as a promising treatment option for patients in whom metformin and the other DPP-4 inhibitors are either contraindicated or require dose adjustment because of moderate to severe renal impairment.

Gut hormones as peripheral anti obesity targets.

Many peptides are synthesised and released from the gastrointestinal tract. Whilst their roles in regulation of gastrointestinal function have been known for some time, it is now evident that they also influence eating behaviour and thus potential anti obesity targets. Peptide YY (PYY) is released post prandially from the gastrointestinal L-cells with glucagon-like peptide 1 (GLP-1) and oxyntomodulin. Following peripheral administration of PYY 3-36, the circulating form of PYY, to mouse, rat or human there is marked inhibition of food intake. PYY 3-36 is thought to mediate its actions through the NPY Y2 GPCR. Obese subjects have lower basal fasting PYY levels and have a smaller post prandial rise. However, obesity does not appear to be associated with resistance to PYY (as it is with leptin) and exogenous infusion of PYY 3-36 results in a reduction in food intake by 30% in an obese group and 31% in a lean group. GLP-1 or oxyntomodulin, products of the prepreglucagon gene, decrease food intake when administered either peripherally or directly into the CNS. In addition, both have been shown to decrease food intake in humans. These effects are thought to be mediated by the GLP-1 receptor. Ghrelin, a huger hormone produced by the stomach, increases in the circulation following a period of fasting. Administration of ghrelin either peripherally or directly into the CNS increases food intake and chronic administration leads to obesity. Further infusion into normal healthy volunteers increases both food intake and appetite. Ghrelin is thought to act through the growth hormone secretagogue receptor (GHS-R). Obesity is the current major cause of premature death in the UK, killing almost 1000 people a week. Worldwide its prevalence is accelerating. The administration of the naturally occurring gut hormone may offer a long-term therapeutic approach to weight control. Here we consider the therapeutic potential of some gut hormones, and the GPCR's through which they act, in the treatment of obesity.