GLP-1 receptor agonist as treatment for cancer as well as diabetes: beyond blood glucose control

The effect of GLP-1R agonists on the medical triad of obesity, diabetes, and cancer

Glucagon-like peptide-1 receptor (GLP-1R) agonists have garnered significant attention for their therapeutic potential in addressing the interconnected health challenges of diabetes, obesity, and cancer. The role of GLP-1R in type 2 diabetes mellitus (T2DM) is highlighted, emphasizing its pivotal contribution to glucose homeostasis, promoting β-cell proliferation, and facilitating insulin release. GLP-1R agonists have effectively managed obesity by reducing hunger, moderating food intake, and regulating body weight. Beyond diabetes and obesity, GLP-1R agonists exhibit a multifaceted impact on cancer progression across various malignancies. The mechanisms underlying these effects involve the modulation of signaling pathways associated with cell growth, survival, and metabolism. However, the current literature reveals a lack of in vivo studies on specific GLP-1R agonists such as semaglutide, necessitating further research to elucidate its precise mechanisms and effects, particularly in cancer. While other GLP-1R agonists have shown promising outcomes in mitigating cancer progression, the association between some GLP-1R agonists and an increased risk of cancer remains a topic requiring more profound investigation. This calls for more extensive research to unravel the intricate relationships between the GLP-1R agonist and different cancers, providing valuable insights for clinicians and researchers alike.

Activation of overexpressed glucagon-like peptide-1 receptor attenuates prostate cancer growth by inhibiting cell cycle progression

AIMS/INTRODUCTION

Incretin therapy is a common treatment for type 2 diabetes mellitus. We have previously reported an anti-prostate cancer effect of glucagon-like peptide-1 receptor (GLP-1R) agonist exendin-4. The attenuation of cell proliferation in the prostate cancer cell line was dependent on GLP-1R expression. Here, we examined the relationship between human prostate cancer severity and GLP-1R expression, as well as the effect of forced expression of GLP-1R using a lentiviral vector.

MATERIALS AND METHODS

Prostate cancer tissues were extracted by prostatectomy and biopsy. GLP-1R was overexpressed in ALVA-41 cells using a lentiviral vector (ALVA-41-GLP-1R cells). GLP-1R expression was detected by immunohistochemistry and quantitative polymerase chain reaction. Cell proliferation was examined by growth curves and bromodeoxyuridine incorporation assays. Cell cycle distribution and regulators were examined by flow cytometry and western blotting. In vivo experiments were carried out using a xenografted model.

RESULTS

GLP-1R expression levels were significantly inversely associated with the Gleason score of human prostate cancer tissues. Abundant GLP-1R expression and functions were confirmed in ALVA-41-GLP-1R cells. Exendin-4 significantly decreased ALVA-41-GLP-1R cell proliferation in a dose-dependent manner. DNA synthesis and G1-to-S phase transition were inhibited in ALVA-41-GLP-1R cells. SKP2 expression was decreased and p27Kip1 protein was subsequently increased in ALVA-41-GLP-1R cells treated with exendin-4. In vivo experiments carried out by implanting ALVA-41-GLP-1R cells showed that exendin-4 decreased prostate cancer growth by activation of GLP-1R overexpressed in ALVA41-GLP-1R cells.

CONCLUSIONS

Forced expression of GLP-1R attenuates prostate cancer cell proliferation by inhibiting cell cycle progression in vitro and in vivo. Therefore, GLP-1R activation might be a potential therapy for prostate cancer.