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.
Objective To investigate the mechanism of adenosine-tri phosphate (ATP) activated mammal ian target of rapamycin (mTOR)/signal transducer and activator of transcription 3 (STAT3) signal pathway in the physiology and pathology of spinal cord injury (SCI). Methods Ninety-six adult healthy female Sprague-Dawley rats were randomly divided into 4 groups (groups A, B, C and D, n=24). In groups A, B and C, the rats were made the SCI models at T8-10 levels by using a modified Allen’ s stall, and in group D, rats were given laminectomy without SCI. The rats were subjected to the administration of ATP (40 mg/kg) for 7 days in group A, to the administration of physiological sal ine (equal-volume) for 7 days in group B, to the administration of ATP (40 mg/kg) and rapamycin (3 mg/kg) for 7 days in group C, and to the administration of physiological sal ine (equal-volume) for 7 days in group D. Locomotor activity was evaluated using the Basso-Beattie-Bresnahan rating scale at the postoperative 1st, 2nd, 3rd, and 4th weeks. Then, the expressions of spinal cord cell marker [Nestin, neuron-specific enolase (NSE), gl ial fibrillary acidic protein (GFAP)] and the mTOR/STAT3 pathway factors (mTOR, STAT3) were detected at the postoperative 1st, 2nd, 3rd, and 4th weeks by immunohistochemistry analysis, Western blot assay, and real-time fluorescence PCR analysis. Results The BBB scores in group A showed a steady increase in the postoperative 1st-4th weeks and were significantly higher than those in groups B and C (P lt; 0.01), but were lower than that in group D (P lt; 0.01). Real-time fluorescence PCR results showed that the mRNA expressions of mTOR, STAT3, NSE of group A steadily increased, however, the Nestin mRNA expression gradually decreased in the postoperative 1st-4th weeks, which were all significantly higher than those of groups B, C, and D (P lt; 0.01). The mRNA expression of GFAP showed a steady increase in group A and was significantly less than those of groups B and C, but was higher than that of group D (P lt; 0.01). There were significant differences (Plt; 0.01) in all markers between groups B, C, and group D; there were significant differences in mTOR, P-mTOR, STAT3, and P-STAT3 mRNA between groups B and C at 1st-4th weeks (P lt; 0.05). The similar changes were found by Western blot assay. Conclusion ATP can activate the mTOR/STAT3 pathway to induce endogenic NSCs to prol iferate and differentiate into neurons in rats, it enhances the heal ing of SCI.
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.
Objective To explore the effect and mechanism of rapamycin and deferoxamin on wound healing after ischemia and hypoxia. Methods The model of ischemia and hypoxia wound was made on the back of 40 SPF male adult Sprague Dawley rats, weight (300±20) g; they were randomly divided into 4 groups (n=10): the control group (group A), deferoxamine intervention group (group B), rapamycin intervention group (group C), and deferoxamine+rapamycin intervention group (group D). At 3, 6, and 9 days after model preparation, rats of groups A, B, C, and D were intra-peritoneally injected with normal saline, deferoxamin (10 mg/kg), rapamycin (3 mg/kg), deferoxamin (10 mg/kg)+rapamycin (3 mg/kg) respectively. The wound healing was observed and the healing time was recorded in each group; the wound healing tissue was harvested to test the mRNA and protein expressions of mammalian target of rapamycin (mTOR), hypoxia inducible factor 1α (HIF-1α), and vascular endothelial growth factor (VEGF) by real-time fluorescence quantitative PCR and Western blot at 2 days after wound healing. Results All rats survived to the end of the experiment, and wounds healed; the healing time of groups A, B, and D was significantly shorter than that of group C (P<0.05), but there was no significant difference between groups A, B, and D (P>0.05). Real-time fluorescence quantitative PCR showed that the expression of mTOR mRNA in groups C and D was significantly decreased when compared with the expressions in groups A and B (P<0.05); there was significant difference between groups A and B (P<0.05), but no significant difference between groups C and D (P>0.05). The expressions of HIF-1α mRNA and VEGF mRNA were signi-ficantly higher in groups B and D than groups A and C, and in group A than group C (P<0.05), but there was no signifi-cant difference between groups B and D (P>0.05). Western blot showed that the relative expressions of mTOR protein in groups C and D were significantly decreased when compared with the expressions in groups A and B (P<0.05), but there was no significant difference between groups C and D (P>0.05). The relative expressions of HIF-1α protein in groups A, B, and C were significantly increased when compared with expression in group D (P<0.05), but there was no significant difference between groups A, B, and C (P>0.05). The relative expression of VEGF protein were significantly lower in groups B, C, and D than group A, in group D than groups B and C, and in group C than group B (P<0.05). Conclusion Defe-roxamin can promote the wound healing of rats after ischemia and hypoxia, and the effect of rapamycin is opposite. It may be related to the existence of mTOR and HIF-1 signaling pathway in chronic ischemia-hypoxia wound.
Objective To observe efficacy of rapamycin combined with sorafenib in hepatocellular carcinoma (HCC) patients with tumor recurrence after liver transplantation beyond Milan criteria. Methods Forty-one beyond Milan criteria HCC patients who underwent the classic orthotopic liver transplantation without bypass and the tumor postoperatively recurred in the Tianjin First Center Hospital from February 1, 2012 to August 31, 2015 were collected retrospectively, then were divided into a local treatment group (n=21) and a comprehensive treatment group (n=20). The local treatment included the surgical resection, radiofrequency ablation, transcatheter arterial chemoembolization, radioactive seed implantation, etc.. The comprehensive treatment was on the basis of the local treatment plus rapamycin in combination with sorafenib. Results There were 12 patients with stable disease and 9 patients with progressive disease in the local treatment group. There were 12 patients with partial response, 10 patients with stable disease and 8 patients with progressive disease in the comprehensive group. In the local treatment group and the comprehensive treatment group, the median survival time were 9 months and 12 months, and the 1-year and 2-year survival rates after the recurrence were 14% versus 55%, 0 versus 15%, respectively. The survival of the comprehensive treatment group was significantly better than that of the local treatment group (P<0.01). Conclusion Combination of rapamycin and sorafenib in HCC patients with tumor recurrence after liver transplantation beyond Milan criteria can significantly improve survival time of patient with recurrence.
ObjectiveTo explore the protective effect of rapamycin on pancreatic damage in severe acute pancreatitis (SAP) and further to explain its protective mechanism.MethodsNinety selected SPF males SD rats were randomly divided into 3 groups: sham-operated group (SO group), SAP group, and rapamycin group (RAPA group), with 30 rats in each group. Then each group of rats were randomly divided into 3 subgroups of 24 h, 36 h, and 48 h, 10 rats in each subgroup. Rats in each group underwent laparotomy, the model was prepared by retrograde injection of solutions into biliopancreatic duct, rats of the SO group were injected with 0.9% normal saline, rats of the SAP group and RAPA group were injected with 5% sodium taurocholate solution, but rats of the RAPA group were injected with rapamycin at 30 min before the injection of 5% sodium taurocholate. All the survival rats in corresponding subgroup were killed at 24 h,36 h, and 48 h after operation respectively, then serum and pancreas tissues of rats were collected, serum inflammatory factors content of IL-1β, IL-6, and TNF-α were detected by ELISA method, expression levels of p-mTOR and p-S6K1 in pancreas were detected by Western blot, pancreas tissues were stained by Hematoxylin-Eosin Staining and pathological changes of pancreas were scored under light microscope.Results① At the timepoint of 24 h, 36 h, and 48 h, the order of the expression levels of p-mTOR and p-S6K1 in pancreatic tissues of 3 groups were all as follows: SO group<RAPA group<SAP group, there were significant difference among any 2 groups (P<0.05). ② IL-1β: at the timepoint of 48 h, the order of the content of IL-1β in 3 groups were as follows: SO group<RAPA group<SAP group, there were significant differences among any 2 groups (P<0.05); IL-6: at the timepoint of 36 h and 48 h, the order of the content of IL-6 in3 groups were as follows: SO group<RAPA group<SAP group, there were significant differences among any 2 groups (P<0.05); TNF-α: at the timepoint of 48 h, the order of the content of TNF-α in 3 groups was as follows: SO/RAPA group<SAP group (P<0.05), but there was no significant difference between the SO group and RAPA group (P>0.05). ③ Pancreatic histological score: at the timepoint of 24 h, 36 h, and 48 h, the order of the pancreatic histological score in3 groups was all as follows: SO group<RAPA group <SAP group, there were significant differences among any 2 groups (P<0.05). ④ The expression levels of p-mTOR and p-S6K1 in pancreatic tissue were positively correlated with the pathological scores of pancreatic tissue (r=0.97, P<0.01; r=0.89, P<0.01).ConclusionRapamycin can reduce the degree of pancreatic damage in SAP and has protective effect on pancreatic tissue.
ObjectiveTo investigate the effects of overexpression of alpha/beta hydrolase domain-containing protein 5 (ABHD5) on the invasion and migration of human colon cancer cell line HCT116 and the pathway of adenosine monophosphate-activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR).MethodsThe expression of ABHD5 in colon cancer tissues and its relationship with clinicopathological features was analyzed by UALCAN database. HCT116 cells were cultured in vitro and transfected with ABHD5 recombinant plasmid, then they were divided into control group, negative transfection group and ABHD5 transfection group. Real time quantitative PCR (qRT-PCR) was used to detect the expression of ABHD5 mRNA in HCT116 cells. The proliferation of HCT116 cells was detected by CCK-8 method. Transwell assay was used to detect the invasion and migration of HCT116 cells. The expression of matrix metalloprotein 9 (MMP-9), E-cadherin, Snail, and AMPK/mTOR pathway proteins p-AMPK, AMPK, p-mTOR and mTOR were detected by Western blot.ResultsThe results of the UALCAN showed that compared with normal colon tissues, the expression of ABHD5 mRNA in colon cancer tissues was decreased (P<0.05), and which in the adenocarcinoma and the N1 stage was lower than that of the mucinous adenocarcinoma (P<0.05) and N0 stage (P<0.05), respectively. Compared with the control group and the negative transfection group, the expression of ABHD5 mRNA in the ABHD5 transfection group was increased (P<0.05), the proliferation inhibition rate of HCT116 cells in the ABHD5 transfection group was increased (P<0.05), the numbers of migration and invasion cells in the ABHD5 transfection group were decreased (P<0.05), the expressions of MMP-9, Snail, p-mTOR and mTOR were reduced, and the expressions of E-cadherin, p-AMPK and AMPK were increased (P<0.05).ConclusionsThe overexpression of ABHD5 can inhibit the invasion and migration of colon cancer HCT116 cells, activate AMPK, and inhibit the expression of mTOR. It suggests that ABHD5 may play a role in inhibiting colon cancer by affecting AMPK/mTOR pathway.
Objective To explore the protective effect of rapamycin on brain tissues injury in severe acute pancreatitis (SAP) and its possible mechanism in experimental rats. Methods Ninety SPF males SD rats were randomly divided into 3 groups by random envelope opening method: sham operation group (SO group), SAP group, and rapamycin group (RAPA group), then the rats of each group were divided into 24 h, 36 h, and 48 h 3 subgroups by random number table method. Rats in each group underwent laparotomy, the model was prepared by retrograde injection of solutions into biliopancreatic duct, rat of the SO group was injected with 0.9% normal saline (2 mL/kg), rats of the SAP group and the RAPA group were injected with 5% sodium taurocholate solution (2 mL/kg), but rat of the RAPA group was injected with rapamycin (1 mg/kg) at 30 min before narcosis. All survival rats in each subgroup were killed at 24 h, 36 h, and 48 h respectively, then the pancreas and brain tissues of rats were collected, pancreas and brain tissues were stained by hematoxylin-eosin staining, brain tissues were stained by Luxol fast blue additionally, pathological changes of brain tissues were scored under light microscope. The protective effect of rapamycin on brain tissues injury was determined by comparing the differences in the degree of brain tissues among 3 groups. The phosphorylated mammaliantarget of rapamycin (p-mTOR) and phosphorylated ribosomal 40S small subunitS6 protein kinase (p-S6K1) expression levels in brain tissues were detected by Western blot. In addition, the correlations between the expression levels of p-mTOR and p-S6K1 in brain tissues and the degree of brain tissues injury were analyzed to further explore the possible mechanism of rapamycin’s protective effect on brain tissues injury in SAP. Results① At the point of 24 h, 36 h, and 48 h, the order of the relative expression levels of p-mTOR and p-S6K1 in brain tissues of three groups were all as follows: the SO group < the RAPA group < the SAP group (P<0.05). ② At the point of 24 h, 36 h, and 48 h, the order of brain histological score in three groups were all as follows: the SO group < the RAPA group < the SAP group (P<0.05). ③ The relative expression levels of p-mTOR and p-S6K1 in brain tissues were positively correlated with pathological scores of brain tissues (r=0.99, P<0.01; r=0.97, P<0.01). ConclusionRapamycin plays a protective role in pancreatic brain tissues injure by down-regulating the expression levels of p-mTOR and p-S6K1 in mTOR signaling pathway.