Oxaliplatin reverses the GLP-1R-mediated promotion of intrahepatic cholangiocarcinoma by altering FoxO1 signaling

Glucagon-like peptide 1 receptor agonist: A potential game changer for cholangiocarcinoma

Glucagon-like peptide-1 receptor (GLP-1R) agonist, a subgroup of incretin-based anti-diabetic therapies, is an emerging medication with benefits in reducing blood glucose and weight and increasing cardiovascular protection. Contrarily, concerns have been raised about GLP-1R agonists increasing the risk of particular cancers. Recently, several epidemiological studies reported contradictory findings of incretin-based therapy on the risk modification for cholangiocarcinoma (CCA). The first cohort study demonstrated that incretin-based therapy was associated with an increased risk of CCA. Later studies, however, showed a null effect of incretin-based therapy on CCA risk for dipeptidyl peptidase-4 inhibitor nor GLP-1R agonist. Mechanistically, glucagon-like peptide 1 receptor is multifunctional, including promoting cell growth. High GLP-1R expressions were associated with progressive phenotypes of CCA cells in vitro. Unexpectedly, the GLP-1R agonist showed anti-tumor effects on CCA cells in vitro and in vivo with unclear mechanisms. Our recent report also showed that GLP-1R agonists suppressed the expression of GLP-1R in CCA cells in vitro and in vivo, leading to the inhibition of CCA tumor growth. This editorial reviews recent evidence, discusses the potential effects of GLP-1R agonists in CCA patients, and proposes underlying mechanisms that would benefit from further basic and clinical investigation.

Liraglutide exhibits potential anti-tumor effects on the progression of intrahepatic cholangiocarcinoma, in vitro and in vivo

Glucagon-like peptide 1 receptor (GLP-1R) agonist is an emerging anti-diabetic medication whose effects on the risk and progression of cholangiocarcinoma (CCA) are controversial. This study aimed to elucidate the roles of GLP-1R and its agonists on intrahepatic CCA (iCCA) progression. Expressions of GLP-1R in iCCA tissues investigated by immunohistochemistry showed that GLP-1R expressions were significantly associated with poor histological grading (P = 0.027). iCCA cell lines, KKU-055 and KKU-213A, were treated with exendin-4 and liraglutide, GLP-1R agonists, and their effects on proliferation and migration were assessed. Exendin-4 and liraglutide did not affect CCA cell proliferation in vitro, but liraglutide significantly suppressed the migration of CCA cells, partly by inhibiting epithelial-mesenchymal transition. In contrast, liraglutide significantly reduced CCA tumor volumes and weights in xenografted mice (P = 0.046). GLP-1R appeared downregulated when CCA cells were treated with liraglutide in vitro and in vivo. In addition, liraglutide treatment significantly suppressed Akt and STAT3 signaling in CCA cells, by reducing their phosphorylation levels. These results suggested that liraglutide potentially slows down CCA progression, and further clinical investigation would benefit the treatment of CCA with diabetes mellitus.

Chidamide Suppresses the Growth of Cholangiocarcinoma by Inhibiting HDAC3 and Promoting FOXO1 Acetylation

Inhibitors for histone deacetylases (HDACs) have been identified as epigenetic drug targets to treat a variety of malignancies through several molecular mechanisms. The present study is aimed at investigating the mechanism underlying the possible antitumor effect of the HDAC inhibitor chidamide (CDM) on cholangiocarcinoma (CCA). Microarray-based gene expression profiling was conducted to predict the expression of HDACs in CCA, which was validated in clinical tissue samples from CCA patients. Next, the proliferation, migration, invasion, autophagy, and apoptosis of human CCA QBC939 and SNU308 cells were measured following treatment with CDM at different concentrations. The acetylation level of FOXO1 in the nucleus and cytoplasm of QBC939 and SNU308 cells was determined after overexpression and suppression of HDAC3. A QBC939-implanted xenograft nude mouse model was established for further exploration of CDM roles in vitro. HDAC3 was prominently expressed in CCA tissues and indicated a poor prognosis for patients with CCA. CDM significantly inhibited cell proliferation, migration, and invasion of QBC939 and SNU308 cells, while inducing their autophagy and apoptosis by reducing the expression of HDAC3. CDM promoted FOXO1 acetylation by inhibiting HDAC3, thereby inducing cell autophagy. Additionally, CDM inhibited tumor growth in vivo via HDAC3 downregulation and FOXO1 acetylation induction. Overall, this study reveals that CDM can exhibit antitumor effects against CCA by promoting HDAC3-mediated FOXO1 acetylation, thus identifying a new therapeutic avenue for the treatment of CCA.

Role of FoxO1 in regulating autophagy in type 2 diabetes mellitus (Review)

Type 2 diabetes mellitus (T2DM) is a major chronic disease that is characterized by pancreatic β-cell dysfunction and insulin resistance. Autophagy is a highly conserved intracellular recycling pathway and is involved in regulating intracellular homeostasis. Transcription factor Forkhead box O1 (FoxO1) also regulates fundamental cellular processes, including cell differentiation, metabolism and apoptosis, and proliferation to cellular stress. Increasing evidence suggest that autophagy and FoxO1 are involved in the pathogenesis of T2DM, including β-cell viability, apoptosis, insulin secretion and peripheral insulin resistance. Recent studies have demonstrated that FoxO1 improves insulin resistance by regulating target tissue autophagy. The present review summarizes current literature on the role of autophagy and FoxO1 in T2DM. The participation of FoxO1 in the development and occurrence of T2DM via autophagy is also discussed.

Liraglutide protects palmitate-induced INS-1 cell injury by enhancing autophagy mediated via FoxO1

Type 2 diabetes mellitus (T2DM) is characterized by insulin resistance and a progressive loss in mass and function of pancreatic β-cells. In T2DM, lipotoxicity leads to β-cells dysfunction and decreases its number. Autophagy serves a crucial role in maintaining the normal islet architecture and the function of β-cells. Moreover, glucagon-like peptide-1 (GLP-1) and its analogs have beneficial roles in pancreatic β-cells. However, the protective effects of GLP-1 agents on palmitate (PA)-induced pancreatic β-cells and their underlying mechanisms are not fully elucidated. Forkhead box O1 (FoxO1) can prevent pancreatic β-cells from apoptosis. Whether GLP-1 protects against PA-induced β-cells injury via FoxO1 remains unknown. The present study exposed INS-1 cells to PA to establish a T2DM injury model. Cell viability was evaluated using a Cell Counting Kit-8 assay, and apoptosis was determined via western blotting. Furthermore, autophagy was examined using western blotting, immunofluorescence and transmission electron microscopy. Silencing FoxO1 was used to inhibit the activities of FoxO1. The results suggested that the GLP-1 analog liraglutide enhanced the cell viability, inhibited the protein expression of cleaved caspase-3 and increased the expression levels of microtubule-associated protein 1 light chain3 (LC3) II/I, and FoxO1 in INS-1 cells. The autophagy inhibitor chloroquine inhibited the protective effects of liraglutide on INS-1 cells. Silencing of FoxO1 decreased the expression levels of LC3-II and attenuated the protection of liraglutide on the viability of INS-1 cells. In conclusion, the results indicated that liraglutide ameliorated the PA-induced islet β-cells injury via the upregulation of autophagy-mediated by FoxO1.

Bioinformatics Analysis Identifies the Estrogen Receptor 1 (ESR1) Gene and hsa-miR-26a-5p as Potential Prognostic Biomarkers in Patients with Intrahepatic Cholangiocarcinoma

Background

Intrahepatic cholangiocarcinoma arises from the epithelial cells of the bile ducts and is associated with poor prognosis. This study aimed to use bioinformatics analysis to identify molecular biomarkers of intrahepatic cholangiocarcinoma and their potential mechanisms.

Material/Methods

MicroRNA (miRNA) and mRNA microarrays from GSE53870 and GSE32879 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed miRNAs (DEMs) associated with prognosis were identified using limma software and Kaplan-Meier survival analysis. Predictive target genes of the DEMs were identified using miRWalk, miRTarBase, miRDB, and TargetScan databases of miRNA-binding sites and targets. Target genes underwent Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Hub genes were analyzed by constructing the protein-protein interaction (PPI) network using Cytoscape. DEMs validated the hub genes, followed by construction of the miRNA-gene regulatory network.

Results

Twenty-five DEMs were identified. Fifteen DEMs were upregulated, and ten were down-regulated. Kaplan-Meier survival analysis identified seven upregulated DEMs and nine down-regulated DEMs that were associated with the overall survival (OS), and 130 target genes were selected. GO analysis showed that target genes were mainly enriched for metabolism and development processes. KEGG analysis showed that target genes were mainly enriched for cancer processes and some signaling pathways. Fourteen hub genes identified from the PPI network were associated with the regulation of cell proliferation. The overlap between hub genes and DEMs identified the estrogen receptor 1 (ESR1) gene and hsa-miR-26a-5p.

Conclusions

Bioinformatics analysis identified ESR1 and hsa-miR-26a-5p as potential prognostic biomarkers for intrahepatic cholangiocarcinoma.