Objective To review the role of mTOR signal pathway in chemo-resistance of gastric cancer. Methods Domestic and international publications related mTOR signal pathway in chemo-resistance of gastric cancer in recent years were collected and reviewed. Results mTOR was a central signaling molecule of mTOR signal pathway， which regulated key cellular processes such as cell growth， cell proliferation， cell metabolism， and angiogenesis. Signaling molecules of mTOR signal pathway were overexpressed in gastric cancer. Moreover， mTOR signal pathway might play an important role in chemo-resistance of gastric cancer， and tumor stem cells were involved in it too. Conclusion As mTOR signal pathway plays an important role in chemo-resistance of gastric cancer， the combination of mTOR inhibitors and chemotherapy drugs may overcome the chemo-resistance of gastric cancer.
Objective To study the p-mammalian target of rapamyein(p-roTOR)expression and its prognostic significance in non-small cell lung cancer(NSCLC)．Methods Immunohistochemical staining of EnVision was applied to investigate the expression of p-roTOR in lung specimens from 59 cases with NSCLC and 10 cases with benign pulmonary diseases(3 pulmonary tuberculosises and 7 inflammatory pseudotumors 1．Results The positive rate of p-mTOR was 40．7％ in NSCLC which was significantly higher than that in the benign pulmonary diseases(x =6．237，P=0．013)．The expression of p-mTOR was closely correlated with age，sex and pTNM stage．Kaplan-Meire survival analysis revealed that the expression of p-mTOR was not correlated significantly with survival days(Log rank test P =0．055)．Conclusion P-mTOR might be a biomark for differential diagnosis of malignant lung disease，but has poor prognostic value．
Objective To review the possible mechanisms of the mammal ian target of rapamycin (mTOR) in theneuronal restoration process after nervous system injury. Methods The related l iterature on mTOR in the restoration ofnervous system injury was extensively reviewed and comprehensively analyzed. Results mTOR can integrate signals fromextracellular stress and then plays a critical role in the regulation of various cell biological processes, thus contributes to therestoration of nervous system injury. Conclusion Regulating the activity of mTOR signaling pathway in different aspects cancontribute to the restoration of nervous system injury via different mechanisms, especially in the stress-induced brain injury.mTOR may be a potential target for neuronal restoration mechanism after nervous system injury.
ObjectiveTo investigate the effect of dexamethasone on mammalian target of rapamycin (mTOR) expression of astrocytes in hippocampus of rats with sepsis associated encephalopathy (SAE). MethodsTotally, 90 cases of 30-day-old male Wistar rats were randomly divided into sham-operation group (n=10) and cecal ligation and puncture (CLP) group (n=80). Models of rats with sepsis were established by CLP. At 12 hours after CLP, if rats appeared lower neurobehavioral scores, abnormal electroencephalogram (EEG) and somatosensory evoked potential (SEP), they were diagnosed with SAE. And then, they were randomly divided into non-treated group and dexamethasone group. Rats in the dexamethasone group were injected with dexamethasone (1 mg/kg) via tail vein every other day for a total of 3 times. The same dose of saline was used in the non-treated group. The neurobehavioral score was measured, SEP and EEG were examined in the age of 40 days, and then the rats were killed and the hippocampus was taken. Expressions of mTOR protein were measured by Western blot. The glial fibrillary acidic protein (GFAP) and mTOR were detected by immunofluorescence assay, and the number of positive cells was calculated by image analysis system software. ResultsSix of 80 CLP rats died in 12 hours after operation, and 28 of 74 rats were diagnosed as SAE because they appeared lower neurobehavioral scores, abnormal EEG and SEP at 12 hours after CLP. The incidence of SAE was 37.84% (28/74). In the age of 40 days, compared with non-treated group, neurobehavioral score of rats in the dexamethasone group was low, the amount of alpha waves in EEG reduced, delta waves increased, the amplitude of P1 waves in SEP was decreased, and the latencies of P1 and N1 waves were prolonged (P＜0.05). GFAP immunofluorescence staining showed astrocytic body and processes were small in the sham operation group. However, astrocytes in the non-treated group had large body and hypertrophic processes, and compared with the sham operation group, the number of these cells increased significantly (P＜0.05). Astrocytic body and processes were small in the dexamethasone group compared with the non-treated group, and the number of cells also decreased (P＜0.05). The mTOR positive astrocytes in the non-treated group were more than those in the sham operation group (P＜0.05). But mTOR positive astrocytes in the dexamethasone group were fewer than those in the non-treated group (P＜0.05). ConclusionsAstrocytes are activated in the hippocampus of rats with SAE. They show features of reactive hyperplasia, and the expression of mTOR is up-regulated, while dexamethasone can inhibit effects on these.
ObjectiveTo explore the involvement of miR-126 and the role of mammalian target of rapamycin (mTOR)/hypoxia-induced factor 1 α (HIF-1 α) pathway in regulating human umbilical cord mesenchymal stem cells (hUCMSCs) exosomes (Exo) on vascular endothelial growth factor (VEGF)-A levels in high glucose-induced human retinal vascular endothelial cells (HRECs). MethodsThe hREC was cultured in EGM-2-MV endothelial cell culture medium with 30 mmol/L glucose and placed in hypoxic cell incubator by 1% oxygen concentration. The cell model of high glucose and low oxygen was established. After modeling, divided HRECs into Exo group, phosphate buffer saline (PBS) group, PBS+anti-miR126 group, Exo+anti-miR126 group, PBS+anti-mTOR group, and PBS+anti-HIF-1 α group. High-glucose and hypoxia-induced hREC in the PBS and Exo groups were respectively co-cultured with PBS and 100 μg/ml hUCMSC Exo. PBS+anti-mTOR group, PBS+anti-HIF-1 α group: 500 nmol/L mTOR inhibitor ADZ2014, 25 μmol/L HIF-1 α inhibitor YC-1 pretreatment for hREC 12 h, and then co-culture with PBS after High-glucose and hypoxia-induced. PBS+anti-miR126 group, Exo+anti-miR126 group: miR-126 LNA power inhibitor probe was transfected with high glucose, and co-cultured with PBS and hUCMSC Exo 6 h after transfection. Real-time polymerase chain reaction (qPCR) measured miRNA-126 expression levels in PBS, and Exo groups for 0, 8, 16 and 24 h. After 24 hof co-culture, the levels of mTOR and HIF-1 α in the cells of PBS and Exo groups were detected by immunofluorescence, Western blot and qPCR, respectively. Western blot, qPCR detection of VEGF-A expression levels in cells of the PBS+anti-mTOR and PBS+anti-HIF-1 α groups. The expression of VE GF-A, mTOR, and HIF-1 α mRNA was measured in cells of PBS+anti-miR126 group and Exo+anti-miR126 group by qPCR. Comparison between two groups was performed by t-test; one-way ANOVA was used for comparison between multiple groups. ResultsAt 0, 8, 16 and 24 h, the relative mRNA expression of miR-126 gradually increased in the Exo group (F=95.900, P＜0.05). Compared with the PBS group, The mTOR, HIF-1 α protein (t=3.466, 6.804), mRNA in HRECs in the Exo group, VEGF-A mRNA expression (t=8.642, 7.897, 6.099) were all downregulated, the difference was statistically significant (P＜0.05). The relative expression level of VEGF-Aprotein (t=3.337, 7.380) and mRNA (t=8.515, 10.400) was decreased in HRECs of the anti-mTOR+PBS group and anti-HIF-1 α+PBS group, differences were statistically significant (P＜0.05). The relative expression of VEGF-A, mTOR, and HIF-1 α mRNA was significantly increased in the cells of the Exo+anti-miR126 group, the differences were all statistically significant (t=4.664, 6.136, 6.247; P＜0.05). ConclusionsmiR-126 plays a role in regulating the effect of hUCMSCs exosomes on VEGF-A levels in high glucose-induced HRECs via mTOR-HIF-1 α pathway.