The protein family of sirtuins and FoXO1 transcription factor have been shown to play significant roles in the aging process. In this study we aimed to investigate the changes in the levels of SIRT2, NFκB and FoXO1 and oxidative parameters of colonic mucosa during aging, and the effects of exogenous melatonin (MLT). A total of twenty-four young (3-months-old) and aged (24 months old) male Wistar rats, divided into control [1% ethanol--phosphate-buffered saline (PBS), s.c. for 21 days] and melatonin (10 mg kg(-1) MLT 1% ethanol in PBS, s.c. for 21 days) were used in the study. The levels of malondialdehyde (MDA) as a parameter of lipid peroxidation, glutathione, NFkB pathway activation, SIRT2 expression, and FoXO1 transcription factor of colonic mucosa were assayed. The MDA levels and SIRT2 expression in the colonic mucosa were significantly increased in the aged group when compared to the younger group. However, the levels of FoXO1 transcription factor were significantly decreased in the aged group. Melatonin significantly decreased the MDA and SIRT2 expression levels of the colonic mucosa in the aged rats. In conclusion, our findings suggest a suppressive role of melatonin in the aging process of colonic tissue via decreasing SIRT2 expression.

Background/aim: The role of angiogenic factors in gastric cancer is not clear. We aimed to assess the role of vascular endothelial growth factor A (VEGFA), angiopoietin 1 (Ang-1), and placental growth factor (PlGF) in the prognosis of patients with advanced gastric cancer.Materials and methods: Thirty consecutive patients treated with a modified DCF (docetaxel, cisplatin, and fluorouracil) regimen were included in the study. The plasma VEGFA, Ang-1, and PlGF levels of the patients before treatment and following two cycles of chemotherapy were measured and evaluated as prognostic factors.Results: Poor performance status and lower Ang-1 levels were correlated with poor overall survival (OS). No significant correlation between VEGFA or PlGF and OS was found. An angiogenesis prognostic index (API) based on the levels of VEGFA, Ang-1, and PlGF was found to be highly correlated with OS. Performance status and API were found as independent prognostic factors for OS. Furthermore, a decrease in VEGFA by 25% from the pretreatment level was also found as a prognostic factor for OS independent of response to DCF regimen. Conclusion:Our results support the use of the new API including VEGFA, Ang-1, and PlGF levels in patients with advanced gastric cancer as a predictor of survival.

Our results suggest that lower doses of chemotherapeutic drugs decrease VEGF secretion from tumor cells without causing substantial cell killing. The data suggest the occurrence of a kind of selective drug-tumor cell type relationship.

Objective: Osteopontin (OPN), a phosphorylated sialoprotein, has been shown to overexpress in a variety of cancers and to contribute tumor progression and metastasis by increasing cell migration and adhesion. In the current study, we aimed to investigate the prognostic and predictive role of OPN in patients with advanced gastric cancer. Methods: A total of 42 consecutive chemonaive patients with advanced gastric cancer and 29 healthy controls were included. The patients were treated with a modified DCF regimen. The blood samples were obtained before each chemotherapy cycle from the patients and once from the healthy controls. The plasma OPN measured by ELISA. Results: The overall response and disease stabilization rates were 25% and 72%, respectively. The median serum OPN level of the patient group was significantly higher compared to healthy controls (176.9 ng/ml (range: 41.5 -521.4) vs 64.3 ng/ml (range 42.1-105.3 ng/ml), p<0.0001).The median overall survival time was 7.0 ± 1.1 (95% CI: 4.9–9.2) months and 1- year overall survival rate was %20.8. The patients who respond to mDCF had lower plasma OPN levels than the nonresponder ones (110.7±29.3 ng/mL, 211.9±24.4 ng/mL respectively, p=0.002). The performance status and the plasma OPN levels were found to be significant factors for overall survival in the multivariate analysis (p=0.004 and 0.016, respectively). Conclusion: The serum OPN seems to be a novel significant prognostic and predictive factor in patients with advanced gastric cancer whom treated with DCF regimen.

Aging is believed to be a first-order risk factor for most neurodegenerative disorders. The neuronal cell loss that occurs with aging has been partly attributed to increased production of nitric oxide and high caspase activity. Melatonin (MLT) might have a role in the regulation of nitric oxide in the brain. We investigated the effects of MLT on the nitrite/nitrate levels and caspase-3 enzyme activity in the frontal cortex, temporal cortex, and hippocampus of young and aged rats. There was no significant difference between the nitrite levels in the frontal cortex and hippocampus of young and aged animals. In the temporal cortex of aged rats, the nitrite level, however, was significantly higher (P < 0.001). In the aged group, MLT significantly decreased these levels in the brain regions. Caspase-3 enzyme activity in the temporal and frontal cortices was significantly higher in aged rats when compared to the control group (P < 0.05). Melatonin did not cause significant changes in caspase-3 activity in any brain region of both young and aged rats. Thus, brain regions demonstrate different caspase-3 enzyme activities and nitrite levels in the aging process. Exogenous MLT administration might delay brain aging (by moderation of death of neurons and glia) via decreasing the nitrite level.