Aim The purpose of this study was to prepare targeted cancer therapy formulation against insulinoma INS‐1 cells and to study its effect on cell death with related mechanisms in vitro. Methods Polylactide‐co‐glycolide (PLGA) nano‐micelles were used for preparation of esculetin nano‐formulation (nano‐esculetin). The cells were treated with nano‐esculetin and free esculetin. Apoptotic and necrotic cell death percentages, cell proliferation, ATP and GTP reductions and insulin levels were investigated on insulinoma INS‐1 cells for both free and nano‐esculetin formulations. Results About 50 mg of PLGA was able to carry 20 mg esculetin in 20 ml of formulation. The obtained optimized formulation was 150 nm, with 92% encapsulation efficiency and a slow‐release behaviour was observed during release studies. Nano‐esculetin bearing 25, 50 and 100 μg esculetin and free esculetin in equivalent doses successfully decreased cell viability. The prevailing cell death mechanism was necrosis. Along with cell proliferation, intracellular insulin and the ratio of ATP and GTP were decreased even with 12.5, 25 and 50 μg esculetin bearing nano‐formulation and its equivalent free esculetin. Conclusions The results revealed that esculetin is able to show its anti‐tumor afficacy after loading to PLGA nano‐micelles and nano‐encapsulation intensifies its cytotoxic activity in vitro. Current study shows that esculetin and its nano formulations are promising agents in treatment of insulinoma.

Purpose Dinutuximab beta is a monoclonal antibody used only in glioblastoma. Streptozotocin is an agent that is particularly toxic to pancreatic beta cells. Dinutuximab beta causes cytotoxicity through natural killer cells and neutrophils and shows effects. In this study, cytotoxicity was induced by streptozotocin without natural killer cells and neutrophils. Gaining the ability to show the effect of Dinutuximab beta without a natural killer was the first aim of this study. This will be especially important in cases where the immune system is deficient, such as cancer. The second aim of the study was to investigate the effects of Dinutuximab beta on cell viability and cell death in insulinoma under the conditions created. Methods The effect of Dinutuximab beta in the presence of natural killer cells in vivo was created by the application of Streptozotocin to Beta-cell tumors of the pancreas in vitro. The cell viability was determined with WST-1 assay. Reactive oxygen species were measured by using dichlorofluorescein diacetate as a spectrophotometer. The cells were marked with DAPI to indicate apoptotic markers (nuclear condensation and fragmentation) with the confocal microscope. GLUT2 (Glucose transporter 2), IR (Insulin receptor), INS1, and INS2 expression levels were analyzed with q-RT-PCR. Results The cell cytotoxicity was induced by Streptozotocin. The cells proliferated with the administration of Dinutuximab beta alone. The result of Dinutuximab beta administered following Streptozotocin administration resulted in more cell death, increased ROS levels, GLUT2, Ins1, and Ins2 mRNA expression levels, and decreased IR mRNA expression levels. Furthermore, the cells predominantly died via apoptosis showing cytoplasmic condensation and DNA fragmentation. Conclusions The lethal effect of Dinutuximab beta without a natural killer was provided by Streptozotocin in Beta cell tumors of the pancreas.

An insulinoma is a tumor formed by beta cells in the Langerhans islets of the pancreas. Vitronectin (VTN), fibronectin (FN) and epidermal growth factor (EGF) are important in cell signaling. The aim of this study was to investigate the molecular mechanism that occurs in INS-1 cells with the administration of VTN, FN and EGF in proliferative doses. We determined the proliferative doses of EGF, VTN and FN. The molecular mechanism of proliferation has been investigated alone or in the combination of these proteins. It was observed that INS-1 cells did not have VTN and FN. Cell viability increased with the administration of 0.1 lg/ml VTN, 0.1 lg/ml FN and 1 mg/ml EGF. Proliferation increased with the administration of FN ? EGF, and VTN ? FN ? EGF together when compared to the control group. The total JNK levels did not change between the groups; however, the active JNK levels increased in the VT ? FN ? EGF group compared to the control group. The total ERK levels increased in the VT ? FN ? EGF group, and the active ERK levels increased in the VTN ? FN, VTN ? EGF and VTN ? FN ? EGF groups compared to the control group. The JNK and ERK pathways are important for proliferation. The JNK and ERK pathways were activated in VTN ? FN ? EGF administered group. However, it was observed that the ERK pathway was more active than the JNK pathway.

Insulinoma INS-1 cell line is a pancreatic beta cell tumor which is characterized with high insulin content and secretion in response to increasing glucose levels. 4-Methylcatechol (4-MC) is a metabolite of quercetin, which is known as a potential drug for inhibition of tumorigenesis. The aim of this study was to determine the applying doses of 4-methylcatechol (4-MC) for triggening cell death and decreasing the cell function of rat insulinoma INS-1 beta cells. The rate of apoptosis and the amount of insulin in the cell and the secretions were determined by the ELISA method. Betacellulin (BTC) and inhibin beta-A amounts in both the cell and the glucose induced secretion were investigated by Western blotting. Furthermore, BTC, Inhibin beta-A, Ins1, Ins2, and GLUT2 gene expression levels were determined by the by the real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) method. We noted a significant decrease in cell viability, while an increase in apoptotic cell death by 4-MC treatment. It caused a decrease in the secretion of BTC, expressions of both BTC and inhibin beta-A. We showed a decrease in the expressions of Ins1 and GLUT2, while there is no alteration in the level of insulin protein. Insulin secretion levels increased in INS-1 cells given 4-MC by basal glucose concentration while they did not response to high concentration of glucose, which indicates that 4-MC disrupts the functionality of INS-1 cells. These results revealed that 4-MC induces apoptosis and decreases insulin secretion by reducing BTC and inhibin beta-A in insulinoma INS-1 cells. Thus, 4-MC may be offered as a potential molecule for treatment of insulinoma.

Insulinomas originate from pancreatic β cells and it is the most widely known tumor. Indomethacin is a nonsteroidal anti‐inflammatory drug, which is used for blocking the production of some natural substances that cause inflammation and decrease pain. In this study, I aimed to investigate the effects of indomethacin on rat insulinoma INS‐1 cells. The relationship between cell death and insulin metabolism was determined with the administration of indomethacin. The cell viability by WST‐1; the apoptosis and necrosis levels by ELISA kits; malondialdehyde levels by spectrophotometer; and beclin, intracellular insulin, insulin secretion, KCa3.1, insulin receptor (IR), glucose transporter type 2 (GLUT2), activating transcription factor 2 (ATF2), Elk1, c‐Jun, Akt and phosphorylated ATF2, Elk1, c‐Jun, Akt, intracellular betacellulin and betacellulin secretion levels by Western blot analysis investigated. The Ins1, Ins2, IR, GLUT2, ATF2, Elk1, c‐Jun, Akt, and Betacellulin gene expression levels were determined by the real‐time quantitative reverse transcription‐polymerase chain reaction method. Apoptotic cell death was observed with the administration of indomethacin. The insulin secretion and Ins1, Ins2 gene expression levels decreased. The insulin receptor and GLUT2 levels increased, while KCa3.1 (KCNN4) levels decreased with the administration of indomethacin to insulinoma INS‐1 cells. A decrease was observed in the total c‐Jun, phosphorylated ATF2, Elk1, c‐Jun, and Akt levels. Betacellulin secretion levels increased. In insulinoma INS‐1 cells, apoptotic cell death occurred in the following manner: (i) indomethacin might decrease insulin secretion by reducing KCa3.1, (ii) might inactivate the JNK/ERK pathway with the inactivity of transcription factors.