Exenatide induces autophagy and prevents the cell regrowth in HepG2 cells

How Far beyond Diabetes Can the Benefits of Glucagon-like Peptide-1 Receptor Agonists Go? A Review of the Evidence on Their Effects on Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is characterized by poor survival rate and quality of life, while available treatments remain generally limited. Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) originally emerged as drugs for the management of diabetes, but have also been shown to alleviate cardiorenal risk. Furthermore, they have demonstrated a wide range of extraglycemic effects that led to their evaluation as potential therapies for a variety of diseases beyond diabetes, such as obesity, neurogenerative disorders and nonalcoholic fatty liver disease. Given the presence of the GLP-1 receptor in hepatocytes, animal data suggest that GLP-1 RAs could regulate molecular pathways that are deeply involved in the genesis and progression of HCC, including inflammatory responses, tumor cell proliferation and oxidative stress, through direct and indirect effects on liver cells. However, future studies must assess several aspects of the benefit-to-risk ratio of the use of GLP-1 RAs in patients with HCC, including co-administration with approved systemic therapies, the incidence of gastrointestinal side effects in a high-risk population, and weight loss management in individuals with poor nutritional status and high rates of cancer cachexia. In this narrative review, we discuss the potential role of GLP-1 analogs in the treatment of HCC, focusing on the molecular mechanisms that could justify a possible benefit, but also referring to the potential clinical implications and areas for future research.

The GLP-1R Agonist Exendin-4 Attenuates Hyperglycemia-Induced Chemoresistance in Human Endometrial Cancer Cells Through ROS-Mediated Mitochondrial Pathway

This study aimed to assess the effects of the antidiabetic drug Exendin-4 (Exe-4), a GLP-1 receptor agonist, on the response of human endometrial cancer cells to chemotherapy under high glucose (HG) conditions. Cell viability was detected using a cell counting kit (CCK)-8. Cell apoptosis and reactive oxygen species (ROS) levels were measured by flow cytometry. Gene expression was evaluated by real-time PCR and immunoblotting. The chemotherapeutic drug cisplatin (DDP) dose-dependently inhibited both human endometrial adenocarcinoma Ishikawa and HEC1B cells, a response reversed by HG. Meanwhile, Exe-4 attenuated hyperglycemia’s effect by elevating intracellular lactate dehydrogenase (LDH) and ROS production. Similarly, DDP-induced elevation of intracellular rhodamine123 was attenuated by HG, and Exe-4 reversed HG’s impact. The chemoresistance genes multidrug resistance-associated protein 1 (MRP1) and P-glycoprotein (Pgp) were upregulated. At the same time, topoisomerase II (TOPO II) was downregulated under HG conditions, suggesting HG-induced chemoresistance. Exe-4 did not significantly influence the above genes. DDP downregulated Bcl-2 and Bcl-XL and upregulated Bax, cytosolic cytochrome c, and PARP under normal glucose (NG) versus HG conditions, and Exe-4 attenuated these effects. Upstream of Bax/Bcl, acetylated P53 was upregulated by DDP and downregulated by HG, whose effect was reversed by Exe-4. DPP treatment significantly induced apoptosis and cell cycle arrest in the S phase under NG, and HG reduced these effects. Prolonged exposure to HG induces DDP chemoresistance in human endometrial cancer cells but is alleviated by Exe-4.

Abnormal Metabolism in the Progression of Nonalcoholic Fatty Liver Disease to Hepatocellular Carcinoma: Mechanistic Insights to Chemoprevention

Nonalcoholic fatty liver disease (NAFLD) is on the rise and becoming a major contributor to the development of hepatocellular carcinoma (HCC). Reasons for this include the rise in obesity and metabolic syndrome in contrast to the marked advances in prevention and treatment strategies of viral HCC. These shifts are expected to rapidly propel this trend even further in the coming decades, with NAFLD on course to become the leading etiology of end-stage liver disease and HCC. No Food and Drug Administration (FDA)-approved medications are currently available for the treatment of NAFLD, and advances are desperately needed. Numerous medications with varying mechanisms of action targeting liver steatosis and fibrosis are being investigated including peroxisome proliferator-activated receptor (PPAR) agonists and farnesoid X receptor (FXR) agonists. Additionally, drugs targeting components of metabolic syndrome, such as antihyperglycemics, have been found to affect NAFLD progression and are now being considered in the treatment of these patients. As NAFLD drug discovery continues, special attention should be given to their relationship to HCC. Several mechanisms in the pathogenesis of NAFLD have been implicated in hepatocarcinogenesis, and therapies aimed at NAFLD may additionally harbor independent antitumorigenic potential. This approach may provide novel prevention and treatment strategies.

Exenatide Attenuates Non-Alcoholic Steatohepatitis by Inhibiting the Pyroptosis Signaling Pathway

BACKGROUND/AIMS

Exenatide is a glucagon-like polypeptide-1 analog, whose main clinical use is to treat type 2 diabetes. However, the mechanism of exenatide in mitigating non-alcoholic steatohepatitis (NASH) remains unclear. This study aimed to investigate the in vitro and in vivo effect of exenatide on NASH.

METHODS

Leptin receptor-deficient C57BL/KsJ- db/db male mice were fed with methionine-choline-deficient (MCD) diet for 4 weeks to induce NASH, while oleic acid/LPS-treated HepG2 cells were used as an in vitro cell model. Exenatide (20 µg/kg/day, subcutaneous) and specific exenatide inhibitors (20 µg/kg/day, intraperitoneal) were used to determine the effects of exenatide on NASH.

RESULTS

Exenatide treatment inhibited the pyroptosis signaling pathway to attenuate NASH.

CONCLUSION

To the best of our knowledge, this report provides the first evidence showing that exenatide attenuated NASH by inhibiting the pyroptosis signaling pathway. Exenatide thus has important pathophysiological functions in NASH and may represent a useful new therapeutic target.

Development and validation of a survival model based on autophagy-associated genes for predicting prognosis of hepatocellular carcinoma

OBJECTIVE

This study aimed to identify the novel prognostic gene signature based on autophagy-associated genes (ARGs) in hepatocellular carcinoma (HCC).

METHODS

The RNA sequencing data and clinical information of HCC and normal tissues were obtained from The Cancer Genome Atlas (TCGA) database. The differentially expressed ARGs were screened by the Wilcoxon signed-rank test. Cox regression analysis and Lasso regression analysis were performed to screen the ARGs and establish the prognostic prediction model. Kaplan-Meier and receiver operating characteristic (ROC) curves were both used to evaluate the accuracy of the model. GSE14520 dataset (testing cohort) was used to validate the prognostic risk model in TCGA. A clinical nomogram was established to predict the survival rate of HCC patients.

RESULTS

Totally 27 differentially expressed ARGs were identified. Three OS-related ARGs (SQSTM1, HSPB8, and BIRC5) were identified via the Cox regression and Lasso regression analyses. Based on these three ARGs, a prognostic prediction model was constructed. HCC patients with high risk score present poorer prognosis than those with low risk score both in TCGA cohort (P=4.478e-04) and testing cohort (P=1.274e-03). Moreover, the risk score curve shows a well feasibility in predicting the patients' survival both in TCGA and GEO cohort with the area under the ROC curve (AUC) of 0.756 and 0.672, respectively. Besides, the calibration curves and C-index indicated that the clinical nomogram performs well to predict survival rate in HCC patients.

CONCLUSIONS

The survival model based on the ARGs may be a promising tool to predict the prognosis in HCC patients.