Monensin is an ionophore antibiotic that inhibits the growth of cancer cells. The aim of this study was to investigate the apoptosis‐mediated anticarcinogenic effects of monensin in SH‐SY5Y neuroblastoma cells. The effects of monensin on cell viability, invasion, migration, and colony formation were determined by XTT, matrigel‐chamber, wound healing, and colony formation tests, respectively. The effects of monensin on apoptosis were determined by real‐time polymerase chain reaction, TUNEL, Western blot, and Annexin V assay. We have shown that monensin suppresses neuroblastoma cell viability, invasion, migration, and colony formation. Moreover, we reported that monensin inhibits cell viability by triggering apoptosis of neuroblastoma cells. Monensin caused apoptosis by increasing caspase‐3, 7, 8, and 9 expressions and decreasing Bax and Bcl‐2 expressions in neuroblastoma cells. In Annexin V results, the rates of apoptotic cells were found to be 9.66 ± 0.01% (p < 0.001), 29.28 ± 0.88% (p < 0.01), and 62.55 ± 2.36% (p < 0.01) in the 8, 16, and 32 μM monensin groups, respectively. In TUNEL results, these values were, respectively; 35 ± 2% (p < 0.001), 34 ± 0.57% (p < 0.001), and 75 ± 2.51% (p < 0.001). Our results suggest that monensin may be a safe and effective therapeutic candidate for treating pediatric neuroblastoma.

Nesfatin-1, identified as an anorexigenic peptide, regulates the energy metabolism by suppressing food intake. The majority of nesfatin-1-synthesizing neurons are concentrated in various hypothalamic nuclei, especially in the supraoptic (SON), arcuate (ARC) and paraventricular nuclei (PVN). We tested the hypothesis that the glutamatergic system regulates nesfatin-1 neurons through glutamate receptors. Therefore, the first aim of the proposed studies was to examine effects of different glutamate agonists in the activation of nesfatin-1 neurons using c-Fos double immunohistochemical labeling. Experimental groups were formed containing male and female rats which received intraperitoneal injections of glutamate agonists kainic acid, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and N-methyl-D-aspartate (NMDA) while the control rats received vehicle. The significant increase in the number of c-Fos-expressing nesfatin-1 neurons after agonist injections were observed both in female and male subjects and some of these effects were found to be sexually dimorphic. In addition, treatment with specific glutamate antagonists 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) or dizocilpine (MK-801) before each of the three agonist injections caused a statistically significant reduction in the number of activated nesfatin-1 neurons in the hypothalamic nuclei including supraoptic, paraventricular and arcuate nuclei. The second aim of the study was to determine the expression of glutamate receptor subunit proteins in the nesfatin-1 neurons by using a double immunofluorescence technique. The results showed that the glutamate receptor subunits, which may form homomeric or heteromeric functional receptor channels, were expressed in the nesfatin-1 neurons. In conclusion, the results of this study suggest that nesfatin-1 neurons respond to glutamatergic signals in the form of neuronal activation and that the glutamate receptors that are synthesized by nesfatin-1 neurons may participate in the glutamatergic regulation of these neurons.

Glioblastoma is an aggressive, common and deadly primary intracranial brain tumor in adults. The antitumor activity of erianin, a dibenzyl compound found in Dendrobium chrysotoxum Lindl. extract, has not been previously demonstrated in glioblastoma. We investigated the anticancer activity and underlying mechanisms of erianin in human U373 and A172 glioma cells. The effects of erianin on cell viability, apoptosis, migration and invasion were estimated by the XTT test, the reverse transcription-polymerase chain reaction (RT-PCR)/annexin V wound healing assay, and Matrigel® invasion chamber, respectively. The effective amounts of erianin in U373 and A172 cells were 16 and 64 μM at 48 h, respectively. Erianin also significantly induced apoptosis by inhibiting B-cell lymphoma 2 (Bcl-2), caspase-8, caspase-9 and tumor necrosis factor receptor type 1-associated DEATH domain protein (TRADD), and activation of caspase-3 and BH3 interacting domain death agonist (BID) gene expression. In addition, erianin significantly increased the number of apoptotic cells in U373 and A172 cells and significantly decreased invasion and migration in U373 and A172 cells. Taken together, our results suggest that erianin may be a new therapeutic anticancer drug component with a potent apoptotic effect and a potential for treating glioblastoma.

Neuronostatin, a newly identified anorexigenic peptide, is present in the central nervous system. We tested the hypothesis that neuronostatin neurons are activated by feeding as a peripheral factor and that the glutamatergic system has regulatory influences on neuronostatin neurons. The first set of experiments analyzed the activation of neuronostatin neurons by refeeding as a physiological stimulus and the effectiveness of the glutamatergic system on this physiological stimulation. The subjects were randomly divided into three groups: the fasting group, refeeding group, and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)+refeeding group. We found that refeeding increased the phosphorylated signal transducers and transcription activator-5 (pSTAT5) expression in neuronostatin-positive neurons and that the CNQX injection significantly suppressed the number of pSTAT5-expressing neuronostatin neurons. The second set of experiments analyzed the activation pathways of neuronostatin neurons and the regulating effects of the glutamatergic system on neuronostatin neurons. The animals received intraperitoneal injections of glutamate receptor agonists (kainic acid, α-amino-3-hydroxy-5methyl-4-isoazepropionic acid (AMPA), and N-methyl-D-aspartate (NMDA)) or 0.9% NaCl. The number of c-Fos-expressing neuronostatin neurons significantly increased following the AMPA and NMDA injections. In conclusion, we found that the neuronostatin neurons were activated by peripheral or central signals, including food intake and/or glutamatergic innervation, and that the glutamate receptors played an important role in this activation.

Kolorektal kanser, dünyada kanser ilişkili ölümlerin en yaygın dördüncü sebebidir. Erianin antioksidan ve anti-tümör etkilere sahip Dendrobium ekstraktından elde edilen yeni bir dibenzil bileşiğidir. Bu çalışmada, erianinin HT29 kolorektal kanser hücreleri üzerine olan terapötik etkileri araştırılmıştır. Erianinin HT29 hücre canlılığı üzerine etkileri XTT test ile koloni oluşumu üzerine etkileri ise koloni formasyonu ile değerlendirilmiştir. Erianinin HT29 hücrelerinde IC50 değeri 48. saatte 59.05 μM olarak belirlenmiştir. HT29 hücre dizisinde erianin uygulanan grupta koloni sayısı 67±33 iken kontrol grubunda 350±89 olarak hesaplanmıştır. Erianin, HT29 kolorektal kanser hücrelerinde koloni oluşumunu ise anlamlı derecede azaltmıştır. Yapılan çalışmaların sonuçları, erianinin kolorektal kanser tedavisinde doğal elde edilen bir bileşik olarak güvenli, kolay ulaşılabilir ve umut veren terapötik bir ilaç olabileceğini destekler niteliktedir. Gelecekte erianinin kolorektal kanser hücreleri üzerindeki etki mekanizmasını aydınlatacak daha kapsamlı ve çok merkezli desteklenecek ileri düzeyde klinik çalışmalara ihtiyaç vardır.