Tumor location, clinicopathological features, and perioperative and prognostic outcomes in patients who underwent pancreatic resection following neoadjuvant chemoradiotherapy for resectable pancreatic cancer: A retrospective study.

BACKGROUND: /Objective: Preoperative treatment of resectable pancreatic ductal adenocarcinoma (PDAC) is gaining popularity worldwide. However, the characteristics of tumors located in the pancreatic head (Ph), or those in the body or tail (Pbt), after surgery following neoadjuvant chemoradiotherapy (NACRT) remain unclear. This study aimed to evaluate and compare the clinicopathological features, perioperative outcomes, and prognosis of patients with resectable PDAC who underwent NACRT followed by curative pancreatic resection, focusing on distinguishing between Ph and Pbt PDACs. METHODS: We included 107 patients with resectable PDAC who underwent curative resection following NACRT between 2009 and 2023. Clinicopathological features, perioperative and prognostic outcomes, recurrence patterns, and prognoses were compared between Ph and Pbt PDAC groups. RESULTS: Tumors were found in the Ph and Pbt in 64 and 43 patients, respectively. Albumin levels and lymphocyte-to-monocyte ratios after NACRT were significantly lower in the Ph group than in the Pbt group. The Pbt group showed significantly higher rates of positive peritoneal lavage cytology and serosal, arterial, and portal vein invasion than the Ph group did. Overall and recurrence-free survival were similar between the two groups. The most common site of initial postoperative recurrence was the lung only in both groups; however, the rate of peritoneal dissemination only was significantly higher in the Pbt group than in the Ph group. CONCLUSIONS: The prognoses based on tumor locations in the Ph and Pbt after surgery following NACRT are similar. Following the resection of resectable Pbt PDAC, the possibility of peritoneal dissemination recurrence should be considered.

Anti-diabetic drug metformin inhibits cell proliferation and tumor growth in gallbladder cancer via G0/G1 cell cycle arrest.

Gallbladder cancer is the most common biliary tract cancer with poor prognosis and wide variation in incidence rates worldwide, being very high in some countries in Latin America and Asia. Treatment of type 2 diabetes with metformin causes a reduction in the incidence of cancer. Till date, there are no reports on the anti-tumor effects of metformin in gall bladder cancer. Therefore, this study evaluated the effects of metformin on the proliferation of human gallbladder adenocarcinoma cells in vitro and in vivo, as well as explored the microRNAs associated with the anti-tumor effects of metformin. Metformin inhibited the proliferation in gallbladder adenocarcinoma cell lines NOZ, TGBC14TKB, and TGBC24TKB, and blocked the G0 to G1 transition in the cell cycle. This was accompanied by strong reduction in the expression of G1 cyclins, especially cyclin D1 and its catalytic subunits including cyclin-dependent kinase 4, and in retinoblastoma protein phosphorylation. In addition, metformin reduced the phosphorylation of receptor tyrosine kinases, especially Tie-2, ALK, PYK, EphA4, and EphA10, as well as angiogenesis-related proteins, including RANTES, TGF-ß, and TIMP-1. Moreover, metformin also markedly altered microRNA expression profile leading to an anti-tumor effect. Treatment of athymic nude mice bearing xenograft tumors with metformin inhibited tumor growth. These results suggest that metformin may be used clinically for the treatment of gallbladder adenocarcinoma.

Predictive role of the prognostic nutritional index in patients with pancreatic ductal adenocarcinoma who underwent neoadjuvant chemoradiotherapy followed by curative pancreatic resection: A retrospective study using prospectively collected data.

BACKGROUND: Despite a strong association between nutritional indices and disease prognosis, evidence regarding the evaluation of nutritional indices after preoperative treatment for pancreatic ductal adenocarcinoma (PDAC) is insufficient. We evaluated the clinical significance of the prognostic nutritional index (PNI) in patients with resectable (R-) and borderline resectable (BR-) PDAC who received neoadjuvant chemoradiotherapy (NACRT) followed by pancreatic resection. METHODS: We assessed 153 patients with R- and BR-PDAC who underwent NACRT followed by curative resection between 2009 and 2022. We evaluated the association between preoperative PNI after NACRT and short- and long-term outcomes. RESULTS: The median preoperative PNI value after NACRT was 42.1, and the optimal cutoff value from the time-dependent receiver operating characteristic curve was 38.6. The low PNI group (PNI < 38.6, n = 44) exhibited significantly worse inflammatory parameters, surgical outcomes, and prognoses than the high PNI group (PNI ≥ 38.6, n = 109). Multivariate analysis identified preoperative PNI ≤ 38.6 (hazard ratio [HR]: 2.32, 95% confidence interval [CI]: 1.00-5.38, p = .049), blood loss ≥1642 mL (HR: 3.05, 95% CI: 1.65-5.64, p < .001), node positive pathology (HR: 2.10, 95% CI: 1.32-3.34, p = .002), and lack of postoperative adjuvant chemotherapy (HR: 3.55, 95% CI: 2.05-6.15, p < .001) as significant predictors of overall survival. CONCLUSIONS: For patients with R- and BR-PDAC receiving preoperative treatment, it is imperative to closely monitor their nutritional status when determining the optimal surgical procedure timing.

Short- and Long-Term Outcomes of Neoadjuvant Chemoradiotherapy Followed by Pancreatoduodenectomy in Elderly Patients with Resectable and Borderline Resectable Pancreatic Cancer: A Retrospective Study.

Background: The efficacy of neoadjuvant chemoradiotherapy (NACRT) followed by pancreatoduodenectomy (PD) in elderly patients with pancreatic ductal adenocarcinoma (PDAC) remains unclear. Methods: This retrospective analysis of prospectively collected data examined the effect of NACRT followed by PD in elderly patients with PDAC. A total of 112 patients with resectable (R-) and borderline resectable (BR-) PDAC, who were planned for PD and received NACRT between 2009 and 2022, were assessed. Changes induced by NACRT, surgical outcomes, nutritional status, renal and endocrine functions, and prognosis were compared between elderly (≥75 years, n = 43) and non-elderly (<75 years, n = 69) patients over two years following PD. Results: Completion and adverse event rates during NACRT, nutritional status, renal function, endocrine function over two years postoperatively, and prognosis did not significantly differ between the two groups. Low prognostic index after NACRT and the absence of postoperative adjuvant chemotherapy may be adverse prognostic indicators for elderly patients undergoing NACRT for R- and BR-PDAC. Conclusions: Despite a higher incidence of postoperative complications, NACRT followed by PD can be safely performed in elderly patients, resulting in a prognosis similar to that in non-elderly patients.

Use of endoscopic gallbladder stenting and biliary scintigraphy for diagnosis of gallbladder dyskinesia: a case report.

A 40-year-old woman visited our hospital with a several-year history of right hypochondriac pain and vomiting after eating. She had been treated for functional dyspepsia, with no improvement in her symptoms. No gallstones were detected on imaging tests, but papillary insufficiency or dyskinesia of the gallbladder was suspected and biliary scintigraphy was performed. Biliary scintigraphy showed delayed excretion of radionuclides from the gallbladder and bile ducts into the duodenum. We initially suspected papillary dysfunction and performed endoscopic sphincterotomy, but there was no improvement in her symptoms. Biliary scintigraphy also showed delayed excretion of radionuclides, especially stagnation of radionuclides in the gallbladder. We suspected gallbladder dyskinesia and performed endoscopic gallbladder stenting, after which her symptoms disappeared and biliary scintigraphy showed improved excretion of radionuclides into the duodenum. Endoscopic gallbladder stenting may be useful for the diagnosis of gallbladder dyskinesia and for determining the efficacy of cholecystectomy.

Functional Assessment of Cardiac Arrest Hepatocytes and Effect of Mechanical Perfusion on Function in a Rat Model.

BACKGROUND: Hepatocyte transplantation has been reported to be useful for metabolic diseases and acute liver failure. However, the shortage of donors limits its widespread use. The use of livers from donors after circulatory death, which are currently unavailable for liver transplantation, may alleviate donor shortage. In this study, we investigated the effects of mechanical perfusion on cardiac arrest hepatocytes in a rat model using cardiac arrest donor livers, and we evaluated the function of cardiac arrest hepatocytes. METHODS: F344 rat hepatocytes isolated from livers removed during cardiac pulsation were compared with those isolated from livers removed after 30 minutes of warm ischemia after cardiac arrest. We then compared hepatocytes isolated from livers removed after 30 minutes of warm ischemia with those isolated after 30 minutes of mechanical perfusion before isolation. The yield per liver weight, ammonia removal capacity, and adenosine diphosphate/adenosine triphosphate ratio were evaluated. RESULTS: Thirty minutes of warm inhibition reduced hepatocyte yield but did not alter ammonia removal capacity and energy status. Mechanical perfusion increased hepatocyte yield and improved the adenosine diphosphate/adenosine triphosphate ratio after 30 minutes of warm inhibition. CONCLUSION: Thirty minutes of warm ischemic time may decrease isolated hepatocyte yield without degrading their function. If increased yields are obtained, livers from donors dying of cardiac arrest could be used for hepatocyte transplantation. The results also suggest that mechanical perfusion may positively affect the energy status of hepatocytes.

Clinical Significance of the Mac-2 Binding Protein Glycosylated Isomer as a Surrogate Marker of Graft Fibrosis After Pediatric Liver Transplantation.

BACKGROUND: After pediatric liver transplantation, liver fibrosis may occur during long-term follow-up. Noninvasive markers for assessing this liver fibrosis are desired. Mac-2 binding protein glycosylated isomer (M2BPGi) has recently been reported as a useful biomarker for liver fibrosis. However, its usefulness in the pediatric population is yet to be established. This study investigated the clinical significance of M2BPGi levels as a surrogate marker of graft fibrosis after pediatric liver transplantation. METHODS: We retrospectively identified 96 patients who underwent pediatric liver transplantation at our institution between 1991 and 2015. The association between M2BPGi levels and other fibrosis markers was analyzed in 60 patients in whom fibrosis markers were measured. The association between fibrosis marker levels and graft fibrosis was assessed in 42 patients who underwent biopsies between 2016 and 2022. RESULTS: The M2BPGi levels were statistically correlated with the hyaluronic acid and type-IV collagen levels. None of the fibrosis markers were significantly associated with liver graft fibrosis, although the levels of these markers were slightly higher in patients with severe liver fibrosis than in those with mild fibrosis. CONCLUSIONS: The M2BPGi levels had a limited ability to assess liver graft fibrosis after pediatric liver transplantation, similar to other fibrosis markers. Further studies with larger cohorts are required to validate these findings externally.

Antitumor Effect of Galectin-9 on Cell Proliferation and Tumor Growth of Human Duodenal Adenocarcinoma Cells.

BACKGROUND/AIM: Galectin-9 (Gal-9) induces tumor cell apoptosis in lymphoma and other malignant cell types. Duodenal adenocarcinoma is a rare malignancy, and there are insufficient data to determine a standard therapeutic approach. Here, we investigated the antitumor effect of Gal-9 in HuTu-80 duodenal adenocarcinoma cells. MATERIALS AND METHODS: Cell proliferation was examined in HuTu-80 cells using a Cell Counting Kit-8 assay. Cell cycle analysis, apoptosis array, and microRNA expression analysis were performed to identify the effect of Gal-9 on HuTu-80 cells. The antitumor effect of Gal-9 was also examined using xenograft mouse models. RESULTS: Gal-9 suppressed the proliferation of HuTu-80 via blockade of the G0 to G1 cell cycle transition. This blockade was accompanied by a strong decrease in cyclin D1 and phosphorylated Rb, suggesting a G1 arrest. Additionally, Gal-9 induced apoptosis, and the expression of cleaved caspase-3 was increased in Gal-9-treated HuTu-80 cells according to the apoptosis array. MiRNA microarrays revealed that Gal-9 altered the expression of miRNAs in HuTu-80 cells. CONCLUSION: These data demonstrate the therapeutic potential of Gal-9 and provide molecular mechanistic insights into its antitumor effect in HuTu-80 cells.

Repeated balloon inflation under low pressure may reduce serious adverse events during endoscopic papillary large balloon dilation.

Highlight Kamada and colleagues devised a new technique for effective endoscopic papillary large balloon dilation without high balloon pressure. Advantages of the technique include the prevention of unintentional over-pressurization of the balloon by limiting the balloon inflation pressure and reduced risk of pancreatitis due to continuous pancreatic duct obstruction.

Cotransplantation With Adipose Tissue-derived Stem Cells Improves Engraftment of Transplanted Hepatocytes.

BACKGROUND: Hepatocyte transplantation is expected to be an alternative therapy to liver transplantation; however, poor engraftment is a severe obstacle to be overcome. The adipose tissue-derived stem cells (ADSCs) are known to improve engraftment of transplanted pancreatic islets, which have many similarities to the hepatocytes. Therefore, we examined the effects and underlying mechanisms of ADSC cotransplantation on hepatocyte engraftment. METHODS: Hepatocytes and ADSCs were cotransplanted into the renal subcapsular space and livers of syngeneic analbuminemic rats, and the serum albumin level was quantified to evaluate engraftment. Immunohistochemical staining and fluorescent staining to trace transplanted cells in the liver were also performed. To investigate the mechanisms, cocultured supernatants were analyzed by a multiplex assay and inhibition test using neutralizing antibodies for target factors. RESULTS: Hepatocyte engraftment at both transplant sites was significantly improved by ADSC cotransplantation ( P < 0.001, P < 0.001). In the renal subcapsular model, close proximity between hepatocytes and ADSCs was necessary to exert this effect. Unexpectedly, ≈50% of transplanted hepatocytes were attached by ADSCs in the liver. In an in vitro study, the hepatocyte function was significantly improved by ADSC coculture supernatant ( P < 0.001). The multiplex assay and inhibition test demonstrated that hepatocyte growth factor, vascular endothelial growth factor, and interleukin-6 may be key factors for the abovementioned effects of ADSCs. CONCLUSIONS: The present study revealed that ADSC cotransplantation can improve the engraftment of transplanted hepatocytes. This effect may be based on crucial factors, such as hepatocyte growth factor, vascular endothelial growth factor, and interleukin-6, which are secreted by ADSCs.

Telomerase Reverse Transcriptase Promoter Mutations in Human Hepatobiliary, Pancreatic and Gastrointestinal Cancer Cell Lines.

BACKGROUND/AIM: The promoter region of the telomerase reverse transcriptase (TERT) gene is a regulatory element capable of affecting TERT expression, telomerase activity, and telomerase length. Mutations within the TERT promoter region are the most common mutations in many cancers. In this study, we characterized the TERT promoter mutation status in hepatobiliary, pancreatic, and gastrointestinal cancer cell lines. MATERIALS AND METHODS: TERT promoter mutation status was assessed by digital PCR in 12 liver cancer, 5 cholangiocarcinoma (CCA), 12 pancreatic cancer, 17 gastrointestinal cancer, and 3 healthy control cell lines. RESULTS: The C228T promoter mutation was detected in 9 liver cancer lines, and the C250T TERT mutation was detected in 1 oesophageal squamous cell carcinoma line. CONCLUSION: The C228T promoter mutation is specific to liver cancer cell lines among various gastrointestinal cancer cell lines. These data will contribute to future research on the tumorigenic mechanisms and clinical use of digital PCR to detect mutations.

MicroRNA profiles following telmisartan treatment in pancreatic ductal adenocarcinoma cells.

Background: Pancreatic ductal adenocarcinoma (PDAC) is the most devastating of all cancers with an extremely poor prognosis. It has few effective and reliable therapeutic strategies. Telmisartan, a widely used antihypertensive drug, is an angiotensin II type 1 (AT1) receptor blocker (ARB). Telmisartan inhibits cancer cell proliferation, but the underlying mechanisms in PDAC, remain unknown. Material and Methods: In the present study, we evaluated the effects of telmisartan on human PDAC cell proliferation in vitro. We assessed the effects of telmisartan on human PDAC cells using the cell lines PK-1 and PANC-1. Results: Telmisartan inhibited the proliferation of these cells via blockade of the G0 to G1 cell cycle transition. This was accompanied by a strong decrease in cyclin D1. Telmisartan was also shown by receptor tyrosine kinase and angiogenesis arrays to reduce the phosphorylation of epidermal growth factor receptor (EGFR), and miRNA expression was markedly altered by telmisartan in PK-1 cells. Conclusion: In conclusion, telmisartan inhibits human PDAC cell proliferation by inducing cell cycle arrest. Furthermore, telmisartan significantly altered miRNA expression in vitro. Taken together, our study demonstrated the therapeutic potential of telmisartan and provides molecular mechanistic insights into its anti-tumor effect on PDAC cells.

Effect of Aspirin on G0/G1 Cell Cycle Arrest and microRNA Signatures in Pancreatic Adenocarcinoma Cells.

BACKGROUND/AIM: Anti-inflammatory drugs, such as aspirin, have attracted attention as anticancer agents that can be applied to standard chemotherapy for pancreatic cancer. This study aimed to examine the antitumour effects and possible fundamental mechanisms of aspirin in pancreatic cancer cells. MATERIALS AND METHODS: We appraised the antitumour effects of aspirin on cell proliferation and tumour growth, cell cycle distribution, apoptosis, signalling pathways, angiogenesis-related proteins, and phosphorylated receptor tyrosine kinases (p-RTKs) and identify miRNAs associated with its antitumour effects. RESULTS: Aspirin inhibited cell proliferation in pancreatic cancer cell lines and induced G0/G1 cell cycle arrest by decreasing the expression of cyclin D1. Aspirin inactivated glycogen synthase kinase (GSK)-3ß but had no effect on the p38 mitogen-activated protein kinase (MAPK) pathway, p-RTKs, or angiogenesis-related molecules. Aspirin treatment statistically increased the expression of 274 miRNAs in PANC-1 cells and 30 miRNAs in PK-8 cells and suppressed the expression of 294 miRNAs in PANC-1 cells and 13 miRNAs in PK-8 cells. CONCLUSION: Aspirin inhibited the proliferation of pancreatic cancer cells and induced cell cycle arrest. Aspirin also inactivated GSK-3ß but not the p38 MAPK pathway. Thus, aspirin may be used in combination with chemotherapeutic agents for pancreatic cancer.

Short-term inhalation of isoflurane improves the outcomes of intraportal hepatocyte transplantation.

Clinical hepatocyte transplantation (HTx) is only performed without general anesthesia, while inhalation anesthetics are usually used in animal experiments. We hypothesized that isoflurane may be a possible reason for the discrepancy between the results of animal experiments and the clinical outcomes of HTx. Syngeneic rat hepatocytes (1.0 × 107) were transplanted to analbuminemic rats with (ISO group) and without (AW group) isoflurane. The serum albumin, AST, ALT, LDH levels and several inflammatory mediators were analyzed. Immunohistochemical staining and ex vivo imaging were also performed. The serum albumin levels of the ISO group were significantly higher in comparison to the AW group (p < 0.05). The serum AST, ALT, LDH levels of the ISO group were significantly suppressed in comparison to the AW group (p < 0.0001, respectively). The serum IL-1ß, IL-10, IL-18, MCP-1, RNTES, Fractalkine and LIX levels were significantly suppressed in the ISO group. The ischemic regions of the recipient livers in the ISO group tended to be smaller than the AW group; however, the distribution of transplanted hepatocytes in the liver parenchyma was comparable between the two groups. Isoflurane may at least in part be a reason for the discrepancy between the results of animal experiments and the clinical outcomes of HTx.

Comparison of plastic stent versus metal stent in preoperative biliary drainage for pancreatic head cancer with neoadjuvant chemoradiotherapy.

BACKGROUND: While neoadjuvant chemotherapy and chemoradiotherapy (NACRT) for pancreatic head cancer are effective, preoperative endoscopic biliary drainage (EBD) is necessary for managing obstructive jaundice and cholangitis during the preoperative waiting period. Nevertheless, ideal choice of stent type is unclear. We compared plastic stents (PS) and metal stents (MS) in these situations. METHODS: We retrospectively studied 43 patients who successfully underwent preoperative EBD prior to NACRT for pancreatic head cancer at a single institution. We divided patients into PS (n = 22) and MS (n = 21) groups. The primary outcome was the rate of re-interventional drainage rate before surgery. Secondary outcomes were rates of EBD-associated and postoperative complications and total costs in the pre- and perioperative periods. RESULTS: The re-intervention rate was significantly greater in the PS group than in the MS group (95% vs 4.8%, respectively, P < 0.05). EBD-associated and postoperative complications were significantly less common in the MS group (P < 0.05). The average total preoperative medical costs were significantly lower in the MS group (PS vs MS: 528,597 vs 395,891 JPY, P = 0.004). CONCLUSIONS: MS can be the first choice for EBD in patients undergoing NACRT for pancreatic head cancer. MS may be less costly overall.

Preferable Transplant Site for Hepatocyte Transplantation in a Rat Model.

Intraportal injection is regarded as the current standard procedure of hepatocyte transplantation (HTx). In islet transplantation, which shares many aspects with HTx, recent studies have clarified that instant blood-mediated inflammatory reaction (IBMIR), characterized by strong innate immune responses, can cause poor engraftment, so other transplant sites to avoid such a reaction have been established. Although IBMIR was reported to occur in HTx, few reports have evaluated alternative transplant sites for HTx. In this study, we sought to determine the optimum transplant site for HTx. Rat hepatocytes (1.0 × 107) were transplanted at the 9 transplant sites (intraportal (IPO), intrasplenic (IS), liver parenchyma, subcutaneous, intraperitoneal, renal subcapsular, muscle, inguinal subcutaneous white adipose tissue, and omentum) of analbuminemic rats. The serum albumin levels, immunohistochemical staining (albumin, TUNEL, and BrdU), and in vivo imaging of the grafts were evaluated. The serum albumin levels of the IPO group were significantly higher than those of the other groups (p < .0001). The BrdU-positive hepatocyte ratio of liver in the IS group (0.9% ± 0.2%) was comparable to that of the IPO group (0.9% ± 0.3%) and tended to be higher than that of the spleen in the IS group (0.5% ± 0.1%, p = .16). Considering the in vivo imaging evaluation and the influence of splenectomy, the graft function in the IS group may be almost entirely achieved by hepatocytes that have migrated to the liver. The present study clearly showed that the intraportal injection procedure is more efficient than other procedures for performing HTx.

Efficacy of Combined Therapy with Drug-Eluting Beads-Transcatheter Arterial Chemoembolization Followed by Conventional Transcatheter Arterial Chemoembolization for Unresectable Hepatocellular Carcinoma: A Multi-Center Study.

EB-TACE has recently been performed because of its lower hepatotoxicity compared to cTACE in less advanced HCC. However, local recurrence at the tumor margins is often observed after DEB-TACE. cTACE involves filling the intratumoral sinusoids with lipiodol-containing anticancer drugs and accumulating in the drainage area, which is the first site of HCC recurrence. The aim of this study is to evaluate the therapeutic effect of DEB-TACE followed by cTACE in HCC patients. Between 2014 and 2020, 65 patients with Barcelona clinic liver cancer (BCLC) stage B (intermediate stage) of HCC were enrolled and divided into two groups: one group received DEB-TACE followed by cTACE (cTACE group) and the other group received only DEB-TACE (non-cTACE group). Sixty-five patients were medically followed. The median observation time was 14 ± 13.1 months after the first DEB-TACE and outcomes were analyzed for multiple factors. Results: The complete response rate was significantly higher in the cTACE group than in the non-TACE group. The analysis showed that the only factor that increased the CR rate in the cTACE group was the total tumor number (less than four). The OS rate of CR patients was higher than that of non-CR patients in the cTACE group. Adverse events in the cTACE group included severe thrombocytopenia but only in one of twenty-seven patients. Conclusions: The combined therapy with DEB-TACE followed by cTACE may be a new effective therapeutic strategy for the intermediate stage of HCC patients.

Metformin Inhibits Proliferation and Tumor Growth of QGP-1 Pancreatic Neuroendocrine Tumor Cells by Inducing Cell Cycle Arrest and Apoptosis.

BACKGROUND/AIM: Pancreatic neuroendocrine tumors (pNETs) are rare pancreatic neoplasms, and therapeutic options for pNETs are limited. Metformin is an anti-hypoglycemic drug that appears to have anticancer effects. However, little is known about the effect of metformin on pNETs. In this study, we investigated the anti-proliferative effect of metformin on a human pNET cell line. MATERIALS AND METHODS: The anti-proliferative properties of metformin were evaluated in QGP-1 and NCI-H727 cells using a cell counting kit-8 assay. Xenograft mouse models were used to assess the tumor effect in vivo. RESULTS: Metformin inhibited the proliferation and anti-tumor growth of QGP-1 cells, accompanied by their arrest during the cell cycle at the G0/G1 phase. Immunohistochemical analysis of tumor tissues revealed down-regulation of cyclin D1 and proliferating cell nuclear antigen in the metformin-treated group. Additionally, metformin induced apoptosis, and the expression of survivin and claspin were decreased in metformin-treated QGP-1 cells according to the apoptosis array. Furthermore, the angiogenic related protein TIMP-1 was down-regulated, and its miRNA expression was altered by metformin in QGP-1 cells. CONCLUSION: Taken together, our study demonstrated the therapeutic potential of metformin and provides molecular mechanistic insights into its anti-tumoral effect on pNETs. This study is the first one describing anti-tumoral effects in pNETs.