哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)是PI3K/Akt通路的下游分子,可接受生长因子、营养、能量等多种信号,是细胞生长和增殖的关键调节分子。许多肿瘤中存在有编码mTOR信号通路相关蛋白的基因突变,这些蛋白的异...哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)是PI3K/Akt通路的下游分子,可接受生长因子、营养、能量等多种信号,是细胞生长和增殖的关键调节分子。许多肿瘤中存在有编码mTOR信号通路相关蛋白的基因突变,这些蛋白的异常表达可引起mTOR通路的过度激活。目前,以mTOR为治疗靶点成为肿瘤治疗的研究新热点。本文就近年来有关mTOR通路及其抑制剂在抗肿瘤方面的研究进展作一综述。展开更多
AIM: To determine the therapeutic efficacy of resveratrol on ulcerative colitis (UC) and its underlying mechanisms. METHODS: The mouse UC model was developed using 5% dextran sulfate sodium. Mice were randomly divided...AIM: To determine the therapeutic efficacy of resveratrol on ulcerative colitis (UC) and its underlying mechanisms. METHODS: The mouse UC model was developed using 5% dextran sulfate sodium. Mice were randomly divided into four groups: normal control, UC model group, resveratrol low-dose group (RLD; 50 mg/kg per day), and resveratrol high-dose group (RHD; 100 mg/kg per day). RESULTS: The results showed that RLD regulates Treg/Th17 balance mainly through reducing the number of Th17 cells, whereas RHD regulates Treg/Th17 balance through both downregulating the number of Th17 cells and upregulating the number of Treg cells. Resveratrol can also regulate the level of plasma and intestinal mucosal cytokines including interleukin (IL)-10, transforming growth factor-beta 1, IL-6, and IL-17. The expressions of hypoxia inducible factor (HIF)-1 alpha, mammalian target of rapamycin (mTOR), and signal transducer and activator of transcription 3 were significantly decreased in the intestinal tissues of mice treated with resveratrol. CONCLUSION: The therapeutic efficacy of resveratrol in UC is dose dependent and closely associated with the regulation of Treg/Th17 balance and the HIF-1 alpha/mTOR signaling pathway.展开更多
Activation of the phosphoinositide 3 kinase(PI3K)/Akt/mammalian target of rapamycin(mTOR) pathway is common in breast cancer. There is preclinical data to support inhibition of the pathway, and phase Ⅰ to Ⅲ trials i...Activation of the phosphoinositide 3 kinase(PI3K)/Akt/mammalian target of rapamycin(mTOR) pathway is common in breast cancer. There is preclinical data to support inhibition of the pathway, and phase Ⅰ to Ⅲ trials involving inhibitors of the pathway have been or are being conducted in solid tumors and breast cancer. Everolimus, an mTOR inhibitor, is currently approved for the treatment of hormone receptor(HR)-positive, human epidermal growth factor receptor 2(HER2)-negative breast cancer. In this review, we summarise the efficacy and toxicity findings from the randomised clinical trials, with simplified guidelines on the management of potential adverse effects. Education of healthcare professionals and patients is critical for safety and compliance. While there is some clinical evidence of activity of mTOR inhibition in HR-positive and HER2-positive breast cancers, the benefits may be more pronounced in selected subsets rather than in the overall population. Further development of predictive biomarkers will be useful in the selection of patients who will benefit from inhibition of the PI3K/Akt/mTOR(PAM) pathway.展开更多
Rapamycin treatment has been shown to increase autophagy activity and activate Akt phosphorylation, suppressing apoptosis in several models of ischemia reperfusion injury. However, little has been studied on the neuro...Rapamycin treatment has been shown to increase autophagy activity and activate Akt phosphorylation, suppressing apoptosis in several models of ischemia reperfusion injury. However, little has been studied on the neuroprotective effects on spinal cord injury by activating Akt phosphorylation. We hypothesized that both effects of rapamycin, the increased autophagy activity and Akt signaling, would contribute to its neuroprotective properties. In this study, a compressive spinal cord injury model of rat was created by an aneurysm clip with a 30 g closing force. Rat models were intraperitoneally injected with rapamycin 1 mg/kg, followed by autophagy inhibitor 3-methyladenine 2.5 mg/kg and Akt inhibitor IV 1 μg/kg. Western blot assay, immunofluorescence staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay were used to observe the expression of neuronal autophagy molecule Beclin 1, apoptosis-related molecules Bcl-2, Bax, cytochrome c, casp ase-3 and Akt signaling. Our results demonstrated that rapamycin inhibited the expression of mTOR in injured spinal cord tissue and up-regulated the expression of Beclin 1 and phosphorylated-Akt. Rapamycin prevented the decrease of bcl-2 expression in injured spinal cord tissue, reduced Bax, cytochrome c and caspase-3 expression levels and reduced the number of apoptotic neurons in injured spinal cord tissue 24 hours after spinal cord injury. 3-Methyladenine and Akt inhibitor IV intervention suppressed the expression of Beclin-1 and phosphorylated-Akt in injured spinal cord tissue and reduced the protective effect of rapamycin on apoptotic neurons. The above results indicate that the neuroprotective effect of rapamycin on spinal cord injury rats can be achieved by activating autophagy and the Akt signaling pathway.展开更多
About 75% of all breast cancers are estrogen receptor(ER)-positive. They generally have a more favorable clinical behavior, prognosis, and pattern of recurrence, and endocrine therapy forms the backbone of treatment. ...About 75% of all breast cancers are estrogen receptor(ER)-positive. They generally have a more favorable clinical behavior, prognosis, and pattern of recurrence, and endocrine therapy forms the backbone of treatment. Anti-estrogens(such as tamoxifen and fulvestrant) and aromatase inhibitors(such as anastrozole, letrozole, and exemestane) can effectively control the disease and induce tumor responses in a large proportion of patients. However, the majority of patients progress during endocrine therapy(acquired resistance) and a proportion of patients may fail to respond to initial therapy(de novo resistance). Endocrine resistance is therefore of clinical concern and there is great interest in strategies that delay or circumvent it. A deeper knowledge of the molecular mechanisms that drive endocrine resistance has recently led to development of new strategies that have the promise to effectivelyovercome it. Many resistance mechanisms have been described, and the crosstalk between ER and growth factor receptor signaling pathways seems to represent one of the most relevant. Compounds that are able to inhibit key elements of these pathways and restore endocrine sensitivity have been studied and more are currently under development. The aim of this review is to summarize the molecular pathophysiology of endocrine resistance in breast cancer and its impact on current clinical management.展开更多
文摘哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)是PI3K/Akt通路的下游分子,可接受生长因子、营养、能量等多种信号,是细胞生长和增殖的关键调节分子。许多肿瘤中存在有编码mTOR信号通路相关蛋白的基因突变,这些蛋白的异常表达可引起mTOR通路的过度激活。目前,以mTOR为治疗靶点成为肿瘤治疗的研究新热点。本文就近年来有关mTOR通路及其抑制剂在抗肿瘤方面的研究进展作一综述。
基金Supported by Outstanding Doctoral Thesis Support Project of Guangdong Province,No.85514045the Technical Research and Development Project of Shenzhen,No.JCYJ20130402092657774the Medical Research Foundation of Guangdong Province,No.B2013347
文摘AIM: To determine the therapeutic efficacy of resveratrol on ulcerative colitis (UC) and its underlying mechanisms. METHODS: The mouse UC model was developed using 5% dextran sulfate sodium. Mice were randomly divided into four groups: normal control, UC model group, resveratrol low-dose group (RLD; 50 mg/kg per day), and resveratrol high-dose group (RHD; 100 mg/kg per day). RESULTS: The results showed that RLD regulates Treg/Th17 balance mainly through reducing the number of Th17 cells, whereas RHD regulates Treg/Th17 balance through both downregulating the number of Th17 cells and upregulating the number of Treg cells. Resveratrol can also regulate the level of plasma and intestinal mucosal cytokines including interleukin (IL)-10, transforming growth factor-beta 1, IL-6, and IL-17. The expressions of hypoxia inducible factor (HIF)-1 alpha, mammalian target of rapamycin (mTOR), and signal transducer and activator of transcription 3 were significantly decreased in the intestinal tissues of mice treated with resveratrol. CONCLUSION: The therapeutic efficacy of resveratrol in UC is dose dependent and closely associated with the regulation of Treg/Th17 balance and the HIF-1 alpha/mTOR signaling pathway.
文摘Activation of the phosphoinositide 3 kinase(PI3K)/Akt/mammalian target of rapamycin(mTOR) pathway is common in breast cancer. There is preclinical data to support inhibition of the pathway, and phase Ⅰ to Ⅲ trials involving inhibitors of the pathway have been or are being conducted in solid tumors and breast cancer. Everolimus, an mTOR inhibitor, is currently approved for the treatment of hormone receptor(HR)-positive, human epidermal growth factor receptor 2(HER2)-negative breast cancer. In this review, we summarise the efficacy and toxicity findings from the randomised clinical trials, with simplified guidelines on the management of potential adverse effects. Education of healthcare professionals and patients is critical for safety and compliance. While there is some clinical evidence of activity of mTOR inhibition in HR-positive and HER2-positive breast cancers, the benefits may be more pronounced in selected subsets rather than in the overall population. Further development of predictive biomarkers will be useful in the selection of patients who will benefit from inhibition of the PI3K/Akt/mTOR(PAM) pathway.
基金supported by the National Natural Science Foundation of China,No.81401004(to XGL)Medical and Health Technology Development Program of Zhejiang Province of China,No.2015-KY1001-036(to XGL)
文摘Rapamycin treatment has been shown to increase autophagy activity and activate Akt phosphorylation, suppressing apoptosis in several models of ischemia reperfusion injury. However, little has been studied on the neuroprotective effects on spinal cord injury by activating Akt phosphorylation. We hypothesized that both effects of rapamycin, the increased autophagy activity and Akt signaling, would contribute to its neuroprotective properties. In this study, a compressive spinal cord injury model of rat was created by an aneurysm clip with a 30 g closing force. Rat models were intraperitoneally injected with rapamycin 1 mg/kg, followed by autophagy inhibitor 3-methyladenine 2.5 mg/kg and Akt inhibitor IV 1 μg/kg. Western blot assay, immunofluorescence staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay were used to observe the expression of neuronal autophagy molecule Beclin 1, apoptosis-related molecules Bcl-2, Bax, cytochrome c, casp ase-3 and Akt signaling. Our results demonstrated that rapamycin inhibited the expression of mTOR in injured spinal cord tissue and up-regulated the expression of Beclin 1 and phosphorylated-Akt. Rapamycin prevented the decrease of bcl-2 expression in injured spinal cord tissue, reduced Bax, cytochrome c and caspase-3 expression levels and reduced the number of apoptotic neurons in injured spinal cord tissue 24 hours after spinal cord injury. 3-Methyladenine and Akt inhibitor IV intervention suppressed the expression of Beclin-1 and phosphorylated-Akt in injured spinal cord tissue and reduced the protective effect of rapamycin on apoptotic neurons. The above results indicate that the neuroprotective effect of rapamycin on spinal cord injury rats can be achieved by activating autophagy and the Akt signaling pathway.
文摘About 75% of all breast cancers are estrogen receptor(ER)-positive. They generally have a more favorable clinical behavior, prognosis, and pattern of recurrence, and endocrine therapy forms the backbone of treatment. Anti-estrogens(such as tamoxifen and fulvestrant) and aromatase inhibitors(such as anastrozole, letrozole, and exemestane) can effectively control the disease and induce tumor responses in a large proportion of patients. However, the majority of patients progress during endocrine therapy(acquired resistance) and a proportion of patients may fail to respond to initial therapy(de novo resistance). Endocrine resistance is therefore of clinical concern and there is great interest in strategies that delay or circumvent it. A deeper knowledge of the molecular mechanisms that drive endocrine resistance has recently led to development of new strategies that have the promise to effectivelyovercome it. Many resistance mechanisms have been described, and the crosstalk between ER and growth factor receptor signaling pathways seems to represent one of the most relevant. Compounds that are able to inhibit key elements of these pathways and restore endocrine sensitivity have been studied and more are currently under development. The aim of this review is to summarize the molecular pathophysiology of endocrine resistance in breast cancer and its impact on current clinical management.
