Expression of GLP-1R protein and its clinical role in intrahepatic cholangiocarcinoma tissues

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.

Dipeptidyl Peptidase-4 Inhibitors and the Risk of Gallbladder and Bile Duct Disease Among Patients with Type 2 Diabetes: A Population-Based Cohort Study

INTRODUCTION

The use of dipeptidyl peptidase-4 (DPP-4) inhibitors may be associated with an increased risk of gallbladder and bile duct disease among patients with type 2 diabetes.

METHODS

We conducted a population-based cohort study using an active comparator, new-user design. We used data from the United Kingdom Clinical Practice Research Datalink to identify patients newly treated with either a DPP-4 inhibitor or sodium-glucose cotransporter-2 (SGLT-2) inhibitor between January 2013 and December 2020. We fitted Cox proportional hazards models with propensity score fine stratification weighting to estimate the hazard ratio (HR) and its 95% confidence interval (CI) for incident gallbladder and bile duct disease associated with DPP-4 inhibitors compared to SGLT-2 inhibitors.

RESULTS

DPP-4 inhibitors were associated with a 46% increased risk of gallbladder and bile duct disease (4.3 vs. 3.0 events per 1000 person-years, HR 1.46, 95% CI 1.17-1.83). At 6 months and 1 year, 745 and 948 patients, respectively, would need to be treated with DPP-4 inhibitors for one patient to experience a gallbladder or bile duct disease.

CONCLUSIONS

In this population-based cohort study, the use of DPP-4 inhibitors, when compared with SGLT-2 inhibitors, was associated with a moderately increased risk of gallbladder and bile duct disease among patients with type 2 diabetes. This outcome was still quite rare with a high number needed to harm at 6 months and 1 year.

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.

Cancer biology in diabetes update: Focusing on antidiabetic drugs

The association of type 2 diabetes with certain cancer risk has been of great interest for years. However, the effect of diabetic medications on cancer development is not fully understood. Prospective clinical trials have not elucidated the long-term influence of hypoglycemic drugs on cancer incidence and the safety for cancer-bearing patients with diabetes, whereas numerous preclinical studies have shown that antidiabetic drugs could have an impact on carcinogenesis processes beyond the glycemic control effect. Because there is no evidence of the safety profile of antidiabetic agents on cancer biology, careful consideration would be required when prescribing any medicines to patients with diabetes and existing tumor. In this review, we discuss the potential influence of each diabetes therapy in cancer 'initiation', 'promotion' and 'progression'.

DPP-4 inhibitors and GLP-1RAs: cardiovascular safety and benefits

Glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors are commonly used treatments for patients with type 2 diabetes mellitus (T2DM). Both anti-diabetic treatments function by playing key modulatory roles in the incretin system. Though these drugs have been deemed effective in treating T2DM, the Food and Drug Administration (FDA) and some members of the scientific community have questioned the safety of these therapeutics relative to important cardiovascular endpoints. As a result, since 2008, the FDA has required all new drugs for glycemic control in T2DM patients to demonstrate cardiovascular safety. The present review article strives to assess the safety and benefits of incretin-based therapy, a new class of antidiabetic drug, on the health of patient cardiovascular systems. In the process, this review will also provide a physiological overview of the incretin system and how key components function in T2DM.

The role of insulin and incretin-based drugs in biliary tract cancer: epidemiological and experimental evidence

Insulin and incretin-based drugs are important antidiabetic agents with complex effects on cell growth and metabolism. Emerging evidence shows that insulin and incretin-based drugs are associated with altered risk of biliary tract cancer (BTC). Observational study reveals that insulin is associated with an increased risk of extrahepatic cholangiocarcinoma (ECC), but not intrahepatic cholangiocarcinoma (ICC) or gallbladder cancer (GBC). This type-specific effect can be partly explained by the cell of origin and heterogeneous genome landscape of the three subtypes of BTC. Similar to insulin, incretin-based drugs also exhibit very interesting contradictions and inconsistencies in response to different cancer phenotypes, including BTC. Both epidemiological and experimental evidence suggests that incretin-based drugs can be a promoter of some cancers and an inhibitor of others. It is now more apparent that this type of drugs has a broader range of physiological effects on the body, including regulation of endoplasmic reticulum stress, autophagy, metabolic reprogramming, and gene expression. In particular, dipeptidyl peptidase-4 inhibitors (DPP-4i) have a more complex effect on cancer due to the multi-functional nature of DPP-4. DPP-4 exerts both catalytic and non-enzymatic functions to regulate metabolic homeostasis, immune reaction, cell migration, and proliferation. In this review, we collate the epidemiological and experimental evidence regarding the effect of these two classes of drugs on BTC to provide valuable information.

The Neglected Role of Bile Duct Epithelial Cells in NASH

Nonalcoholic fatty liver disease (NAFLD) is the most prevalent liver disease worldwide, and affects 25% of the population in Western countries. NAFLD is the hepatic manifestation of the metabolic syndrome, linked to insulin resistance, which is the common pathogenetic mechanism. In approximately 40% of NAFLD patients, steatosis is associated with necro-inflammation and fibrosis, resulting in nonalcoholic steatohepatitis (NASH), a severe condition that may progress to cirrhosis and liver cancer. Although the hepatocyte represents the main target of the disease, involvement of the bile ducts occurs in a subset of patients with NASH, and is characterized by ductular reaction and activation of the progenitor cell compartment, which incites portal fibrosis and disease progression. We aim to dissect the multiple biological effects that adipokines and metabolic alterations exert on cholangiocytes to derive novel information on the mechanisms driven by insulin resistance, which promote fibro-inflammation and carcinogenesis in NASH.

Use of incretin-based drugs and risk of cholangiocarcinoma: Scandinavian cohort study

AIMS/HYPOTHESIS

Concerns have been raised regarding a potential association of use of the incretin-based drugs dipeptidyl peptidase 4 (DPP4) inhibitors and glucagon-like peptide-1 (GLP-1)-receptor agonists with risk of cholangiocarcinoma. We examined this association in nationwide data from three countries.

METHODS

We used data from nationwide registers in Sweden, Denmark and Norway, 2007-2018, to conduct two cohort studies, one for DPP4 inhibitors and one for GLP-1-receptor agonists, to investigate the risk of incident cholangiocarcinoma compared with an active-comparator drug class (sulfonylureas). The cohorts included patients initiating treatment episodes with DPP4 inhibitors vs sulfonylureas, and GLP-1-receptor agonists vs sulfonylureas. We used Cox regression models, adjusted for potential confounders, to estimate hazard ratios from day 366 after treatment initiation to account for cancer latency.

RESULTS

The main analyses of DPP4 inhibitors included 1,414,144 person-years of follow-up from 222,577 patients receiving DPP4 inhibitors (median [IQR] follow-up time, 4.5 [2.6-7.0] years) and 123,908 patients receiving sulfonylureas (median [IQR] follow-up time, 5.1 [2.9-7.8] years) during which 350 cholangiocarcinoma events occurred. Use of DPP4 inhibitors, compared with sulfonylureas, was not associated with a statistically significant increase in risk of cholangiocarcinoma (incidence rate 26 vs 23 per 100,000 person-years; adjusted HR, 1.15 [95% CI 0.90, 1.46]; absolute rate difference 3 [95% CI -3, 10] events per 100,000 person-years). The main analyses of GLP-1-receptor agonists included 1,036,587 person-years of follow-up from 96,813 patients receiving GLP-1-receptor agonists (median [IQR] follow-up time, 4.4 [2.4-6.9] years) and 142,578 patients receiving sulfonylureas (median [IQR] follow-up time, 5.5 [3.2-8.1] years) during which 249 cholangiocarcinoma events occurred. Use of GLP-1-receptor agonists was not associated with a statistically significant increase in risk of cholangiocarcinoma (incidence rate 26 vs 23 per 100,000 person-years; adjusted HR, 1.25 [95% CI 0.89, 1.76]; absolute rate difference 3 [95% CI -5, 13] events per 100,000 patient-years).

CONCLUSIONS/INTERPRETATION

In this analysis using nationwide data from three countries, use of DPP4 inhibitors and GLP-1-receptor agonists, compared with sulfonylureas, was not associated with a significantly increased risk of cholangiocarcinoma.

CD26/DPP-4: Type 2 Diabetes Drug Target with Potential Influence on Cancer Biology

Simple Summary

Dipeptidyl peptidase (DPP)-4 inhibitor is widely used for type 2 diabetes. Although DPP-4/CD26 has been recognized as both a suppressor and inducer in tumor biology due to its various functions, how DPP-4 inhibitor affects cancer progression in diabetic patients is still unknown. The aim of this review is to summarize one unfavorable aspect of DPP-4 inhibitor in cancer-bearing diabetic patients.

Abstract

DPP-4/CD26, a membrane-bound glycoprotein, is ubiquitously expressed and has diverse biological functions. Because of its enzymatic action, such as the degradation of incretin hormones, DPP-4/CD26 is recognized as the significant therapeutic target for type 2 diabetes (T2DM); DPP-4 inhibitors have been used as an anti-diabetic agent for a decade. The safety profile of DPP-4 inhibitors for a cardiovascular event in T2DM patients has been widely analyzed; however, a clear association between DPP-4 inhibitors and tumor biology is not yet established. Previous preclinical studies reported that DPP-4 suppression would impact tumor progression processes. With regard to this finding, we have shown that the DPP-4 inhibitor induces breast cancer metastasis and chemoresistance via an increase in its substrate C-X-C motif chemokine 12, and the consequent induction of epithelial-mesenchymal transition in the tumor. DPP-4/CD26 plays diverse pivotal roles beyond blood glucose control; thus, DPP-4 inhibitors can potentially impact cancer-bearing T2DM patients either favorably or unfavorably. In this review, we primarily focus on the possible undesirable effect of DPP-4 inhibition on tumor biology. Clinicians should note that the safety of DPP-4 inhibitors for diabetic patients with an existing cancer is an unresolved issue, and further mechanistic analysis is essential in this field.

Indirectly radioiodinated exendin-4 as an analytical tool for in vivo detection of glucagon-like peptide-1 receptor in a disease setting

OBJECTIVE

Glucagon-like peptide-1 receptor agonist (GLP-1RA) has been reported to have therapeutic effects on diabetes and various diseases. Precise detection of GLP-1 receptor (GLP-1R) can be useful to diagnose and elucidate the mechanism of such diseases. Here we aimed to develop an imaging probe based on GLP-1RA that has high molar activity and sensitivity for detection of low-level GLP-1R expression in non-pancreatic diseases.

METHODS

We selected the agonist exenatide (Ex4) as the parent peptide of a GLP-1R targeting probe and prepared Cys-Ex4 by addition of an N-terminal Cys residue and labeling with the prosthetic agent N-(3-[125I]iodophenyl)maleimide ([125I]IPM) to generate [125I]Ex4ipm. We evaluated the affinity of [125I]Ex4ipm for GLP-1R, as well as cellular binding profiles in insulinoma and prostate cancer cell lines, and in vivo biodistributions in normal and tumor-bearing mice to assess GLP-1R-dependent accumulation of radioactivity in tissues.

RESULTS

[125I]Ex4ipm was easily synthesized with high radiochemical yield (73%), radiochemical purity (> 99%), and molar activity (81 GBq/µmol) via a thiol/maleimide reaction. Following administration to mice, [125I]Ex4ipm accumulated to high levels in the pancreas (23.3% ID/g), with radioactivity co-localizing in areas having insulin-positive β cells. High amounts of radioactivity also accumulated in insulinomas that overexpressed GLP-1R (27.5% ID/g). In contrast, low amounts of [125I]Ex4ipm accumulation, corresponding to low expression levels of GLP-1R, were observed in prostate cancer cells and xenografts used as a model of non-pancreatic applications.

CONCLUSION

Our results suggested that [123I]Ex4ipm could be valuable for GLP-1R imaging in diabetes, insulinomas, and various diseases related to GLP-1R.

Association of Diabetes Mellitus and Cholangiocarcinoma: Update of Evidence and the Effects of Antidiabetic Medication

Diabetes mellitus (DM) is a risk factor for cancer in many organs and associated with an increased risk of cholangiocarcinoma (CCA). The molecular linkage between these diseases has been demonstrated in preclinical studies, which have highlighted the role of hyperinsulinemia and hyperglycemia in the carcinogenesis and progression of CCA. Recent studies on the emerging role of antidiabetic medication in the development and progression of CCA showed a subclass of antidiabetic drug with a therapeutic effect on CCA. Although associations between CCA, insulin analogues and sulfonylureas are unclear, incretin-based therapy is likely associated with an increased risk for CCA, and may lead to CCA progression, as demonstrated by in vitro and in vivo experiments. In contrast, biguanides, especially metformin, exert an opposite effect, associated with a reduced risk of CCA and inhibited in vitro and in vivo CCA progression. The association between incretin-based therapy and the risk of CCA needs further clarification, as metformin is being studied in an ongoing clinical trial. Understanding the association between DM and CCA is critical for preventing the development of CCA in patients with DM, and for establishing the appropriateness of antidiabetic medication to treat CCA. Determining how metformin affects CCA can lead to repurposing this safe and well-known drug for improving CCA treatment, regardless of the diabetes status of patients.

Incretin-based therapy and risk of cholangiocarcinoma: a nested case-control study in a population of subjects with type 2 diabetes

BACKGROUND AND AIMS

One cohort and several basic science studies have raised suspicion about an association between incretin therapies and cholangiocarcinoma. Our aim was to verify the occurrence of CC in relation to incretin-based medication use versus any antidiabetic treatment in an unselected population of diabetic patients.

METHODS

A population-based matched case-control study was conducted using administrative data from the Region of Piedmont (4,400,000 inhabitants), Italy. From a database of 312,323 patients treated with antidiabetic drugs, we identified 744 cases hospitalized for cholangiocarcinoma from 2010 to 2016 and 2976 controls matched for gender, age and initiation of antidiabetic therapy; cases and controls were compared for exposure to incretin-based medications. All analyses were adjusted for risk factors for CC, as ascertained by hospital discharge records. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by fitting a conditional logistic model.

RESULTS

The mean age of the sampled population (cases and controls, 75 years) was very high, with no gender prevalence. Five per cent was treated with incretin-based medications. After adjusting for possible confounders, we found no increased risk of cholangiocarcinoma associated with the use of either DPP4i (OR 0.98, 95% CI 0.75-1.29: p = 0.89) or GLP-1-RA (OR 1.09, 95% CI 0.63-1.89; p = 0.76) in the 24 months before hospital admission. Neither the duration of the therapy nor the dose modified the risk of cholangiocarcinoma.

CONCLUSIONS

Our findings suggest that, in an unselected population, the use of both classes of incretin-based medications is not associated with an increased risk of cholangiocarcinoma.

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

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer, with a 5-year survival rate of <10%; effective drug treatment for ICC is currently lacking. Glucagon-like peptide-1 receptor (GLP-1R) is upregulated in ICC; however, the functions of GLP-1R in ICC remain unknown. In this study, the upregulation of GLP-1R was confirmed in ICC cells using reverse transcription-quantitative polymerase chain reaction and western blot analysis, and GLP-1R was determined to promote the migration and invasion of ICC cells using Transwell assays. This tumor-promoting effect depended on the upregulation of epithelial-mesenchymal transformation-associated proteins, which was mediated by the FoxO1 signaling pathway. It was also indicated that following oxaliplatin treatment, the effects of GLP-1R on EMT and invasion were reversed. This functional reversion was associated with the reduced phosphorylation of S256 in forkhead box O1 (FoxO1) and an increase in the levels of unphosphorylated FoxO1. These findings suggest that incretin-based therapies may increase the risk of ICC metastasis and should not be used solely for the treatment of patients with ICC.

Incretin based drugs and risk of cholangiocarcinoma among patients with type 2 diabetes: population based cohort study

OBJECTIVE

To determine whether use of dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists are associated with an increased risk of cholangiocarcinoma in adults with type 2 diabetes.

DESIGN

Population based cohort study.

SETTING

General practices contributing data to the UK Clinical Practice Research Datalink.

PARTICIPANTS

154 162 adults newly treated with antidiabetic drugs between 1 January 2007 and 31 March 2017, followed until 31 March 2018.

MAIN OUTCOME MEASURES

Use of DPP-4 inhibitors and GLP-1 receptor agonists was modelled as a time varying variable and compared with use of other second or third line antidiabetic drugs. All exposures were lagged by one year to account for cancer latency and to minimise reverse causality. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals of incident cholangiocarcinoma associated with use of DPP-4 inhibitors and GLP-1 receptor agonists, separately. A post hoc pharmacovigilance analysis was conducted using the World Health Organization's global individual case safety report database, VigiBase, to estimate reporting odds ratios of cholangiocarcinoma.

RESULTS

During 614 274 person years of follow-up, 105 incident cholangiocarcinoma events occurred (rate 17.1 per 100 000 person years). Use of DPP-4 inhibitors was associated with a 77% increased hazard of cholangiocarcinoma (hazard ratio 1.77, 95% confidence interval 1.04 to 3.01). Use of GLP-1 receptor agonists was associated with an increased hazard with a wide confidence interval (hazard ratio 1.97, 0.83 to 4.66). In the pharmacovigilance analysis, the use of DPP-4 inhibitors and GLP-1 receptor agonists were both associated with increased reporting odds ratios for cholangiocarcinoma, compared with use of sulfonylureas or thiazolidinediones (1.63, 1.00 to 2.66, 4.73, 2.95 to 7.58, respectively).

CONCLUSION

Compared with use of other second or third line antidiabetic drugs, use of DPP-4 inhibitors, and possibly GLP-1 receptor agonists, might be associated with an increased risk of cholangiocarcinoma in adults with type 2 diabetes.