The role of the PTEN/mTOR axis in clinical response of rectal cancer patients.

BACKGROUND: Preoperative chemoradiotherapy has long been accepted as a method to improve survival and lifetime quality of rectal cancer patients. However, physiologic effects of these therapies largely depend on the resistance of cells to the radiation, type of chemotherapeutic agents and individual responses. As one of the signaling cascades involved in chemo- or radiation- resistance, the present study focused on several proteins involved in pTEN/Akt/mTOR pathway to explore their prognostic significance. MATERIALS AND METHODS: Samples from advanced stage rectal cancer patients were analyzed to detect expression levels of pTEN/Akt/mTOR pathway related proteins pTEN, mLST8, REDD1, BNIP3, SAG and NOXA, together with p53, by RT-qPCR. Kaplan-Meier analysis was used to assess expression-survival relation and correlations among all proteins and clinicopathological features were statistically analyzed. RESULTS: Except p53, none of the proteins showed prognostic significance. High p53 expression presented clear impact on overall survival and disease free survival. It was also significantly related to pathologic complete response. p53 showed high correlation to local recurrence as well. On the other hand, strong correlation was observed with PTEN expression and tumor response, but not with survival. High associations were also observed between mLST8/REDD1, PTEN and NOXA, confirming their role in the same cascade. CONCLUSION: The contentious role of p53 as a prognostic biomarker in colorectal cancer was further affirmed, while PTEN and REDD1 could be suggested as potential candidates. Additionally, NOXA emerges as a conjunctive element for different signaling pathways.

Biological effects of whole Z.Officinale extract on chronic myeloid leukemia cell line K562.

The anticancer activity of Zingiber officinalis (ginger) is an area of active research. However, data is quite limited regarding its action and mechanism, especially in hematologic cancer types. Here, antiproliferative and apoptotic effects of whole extract of the rhizome of Zingiber officinalis (ZOWE), was investigated in K562 cell line derived from a chronic myeloid leukemia (CML) patient. Various concentrations of whole extract (0, 10, 25, 50 and 100 µM) were tested in K562 cultures. Cytotoxicity and apoptosis was assessed with appropriate methods, as well as cellular ROS levels. In this study, we showed that ZOWE inhibited proliferation of K562 cells substantially, when compared to peripheral blood mononuclear cells (PBMCs) isolated from healthy donor. Increased Bax/Bcl-2 ratio, reduced mitochondrial membrane potential and increased PARP cleavage demonstrated that ZOWE inhibited proliferation by induction of apoptosis. These changes were coupled with an increase of reactive oxygen species (ROS) production. Furthermore, ZOWE addition to the culture also reduced expression levels of survival proteins pAkt and survivin, in a concentration dependent manner. Our results clearly mark that ZOWE causes to a reduction in cell viability, an induction of apoptosis and elevation in ROS levels in chronic myeloid leukemia cells and effects are significantly different from healthy peripheral blood mononuclear cells, further supporting its potential therapeutic value.

Evaluation of the protective effect of Myrtus communis in scopolamine-induced Alzheimer model through cholinergic receptors.

Alzheimer's disease is a progressive neurodegenerative disorder causing common health problem with increasing age. Evidences show that the key symptoms of AD are mainly caused by cholinergic system dysfunction which has a role in cognitive disorders. Cholinergic pathways especially muscarinic receptors like M1 subtype also have a major role in learning, memory, cognitive functions and emotional state. There is no available permanent treatment currently to cure AD or to change its progression. This study was designed to investigate the factors that play important role in pathogenesis of AD and to compare the effects of Galantamine treatment with effects of Myrtus communis treatment. The expression level of M1, ACh, BDNF; AChE activity, GSH level, MDA and MPO activity and AChE gene expression were investigated in scopolamine-induced rat model. Results showed that, administration of MC significantly improves the SCOP-induced reduction of latency and object recognition time; increasing BDNF, M1 and ACh receptor expression levels in the different brain regions. Additionally, MC showed an increased in AChE by enhancing GSH activity and reducing MDA level and MPO activity. In conclusion MC considered as a possible novel therapeutic approach that can be a valuable alternative way in the prevention and treatment of AD.

Effects of extremely low frequency electromagnetic fields on morphine analgesia and tolerance in rats.

Several studies have demonstrated that the electromagnetic fields produce analgesic activity. The aim of this study was to investigate the effects of extremely low frequency (ELF) electromagnetic fields (EMF) on morphine analgesia and tolerance in rats. In the study, 78 adult male Wistar albino rats (approximately 240 ± 12 g) were used. The application of 50 Hz magnetic field, each day the same times for 30 minutes for 15 days, and a total of four times every 15 minute intervals. To constitute morphine tolerance, high dose of morphine (50 mg/kg) were administered for 3 days in rats and tolerance was evaluated on day 4. Prior to analgesia tests, the effective dose (5 mg/kg) of morphine was injected into rats. In the statistical analyzes of the data, analysis of variance (two-way ANOVA) was used and the multiple comparison determined by Tukey tests. The maximum analgesic effect of the 5 mT magnetic field was determined on 7 days. Administration of morphine (5 mg/kg) in rats exposed to a magnetic field, the analgesic effect was significantly higher compared to the morphine group (p < 0.05). Morphine tolerant animals exposed to a magnetic field, the analgesic effect was found significantly higher than morphine tolerant group rats (p < 0.05). Analgesia test data demonstrated that application of ELF-EMFs to rats increases the morphine analgesia and reduces morphine tolerance.

Prognostic role of sensitive-to-apoptosis gene expression in rectal cancer.

AIM: To investigate the association between prognosis of rectal cancer treated with chemoradiotherapy (CRT) and expression of sensitive-to-apoptosis (SAG), B-cell lymphoma-extra large (Bcl-X(L)) and Bcl-2 homologous antagonist/killer (Bak). METHODS: Real-time quantitative polymerase chain reaction was used to determine the expression of proteins of interest, namely SAG, Bcl-X(L), Bak and ß-actin, in rectal carcinoma patients who had a follow-up period of 3 years after CRT. Biopsy specimens were excised from the rectal tumor preceding CRT. RESULTS: SAG, Bcl-X(L) and Bak proteins showed significant correlations with each other. In multivariate analysis, patients with high vs low SAG expression showed a statistically significant difference in 2-year survival rates: 56% vs 73%, respectively (P = 0.056). On the other hand, there were no significant correlations between the expression levels of all three genes and metastatic rates or tumor responses to CRT. Mean overall survival in the patients with elevated SAG expression was 27.1 mo ± 3.9 mo [95% confidence interval (CI): 19.3-34.9], and in patients with reduced expression, it was 32.1 mo ± 2.5 mo (95% CI: 27.3-36.9). The corresponding values for Bcl-X(L) were 28.0 mo ± 4.1 mo (95% CI: 19.9-36.1) and 31.7 mo ± 2.9 mo (95% CI: 26.0-37.5), and those for Bak were 29.8 mo ± 3.7 mo (95% CI: 22.5-37.2) and 30.6 mo ± 2.4 mo (95% CI: 25.5-35.0), respectively. CONCLUSION: Two-year survival rates significantly correlated with low SAG expression, and SAG may be a candidate gene for good prognosis, independent of therapeutic response of different individuals.