To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein express...To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein expression in the patients with human colorectal adenomas and adenocarcinomas.Methods The expression of PTEN,HIF-1 alpha gene was detected by using in situ hybridization,and the VEGF expression levels by immunohistochemistry in colorectal adenomas and primary colorectal adenocarcinoma.Results Strong expression of HIF-1 alpha was detectable in the majority of colorectal dadenocarcinoma,particularly surrounding areas of necrosis in adenocarcinoma.PTEN,HIF-1 alpha mRNA and VEGF protein were positive in 51.6%,67.7% and 59.7% respectively in 62 cases of adenocarcinomas,and 77.8%,44.4% and 33.3% respectively in 18 cases of adenomas.The positive rate of VEGF was higher in the patients with colorectal adenocarcinomas than that in those with adenomas,whereas that of PTEN mRNA was contrary.HIF-1 mRNA expression was correlated significantly with lymph node metastasis,liver metastasis,Duke’s stage and recurrence.During colorectal tumor progression,the expression of HIF-1 alpha mRNA was positively correlated with the VEGF protein expression (χ2= 4.751 ,P<0.05),but negatively with the PTEN mRNA expression(χ2=21.84,P<0.01).Conclusion The absence or low expression of PTEN and the increased levels of HIF-1α and VEGF may paly an important role in carcinogenesis and progression of colorectal carcinoma.These results suggest that VEGF upregulated by HIF-1 alpha gene may be involved in angiogenesis of colorectal adenocarcinoma.4 refs,1 tab.展开更多
Recent studies have shown that phosphatase and tensin homolog-deleted on chromosome ten （PTEN） gene plays an important role in ischemic brain damage and synaptic plasticity. The AdEasy system, which has been widely ...Recent studies have shown that phosphatase and tensin homolog-deleted on chromosome ten （PTEN） gene plays an important role in ischemic brain damage and synaptic plasticity. The AdEasy system, which has been widely used, greatly simplifies preparation of recombinant adenovirus. Therefore, recombinant defective adenovirus vector carrying human PTEN tumor suppressor gene （Ad-PTEN） was constructed using the AdEasy-1 system and was transfected into HEK293 cells for packaging and amplification. Infection efficiency and expression intensity were observed in primary cultured rat hippocampal neurons infected with Ad-PTEN in vitro. Results revealed a cytopathic effect in green fluorescent protein expression, which increased with prolonged time. After three cycles of amplification, the adenovirus titer was increased to an adequate titer for infecting hippocampal neurons. The entire process typically requires 4-5 weeks for completion. Results suggested that recombinant defective adenovirus vector carrying the PTEN gene was successfully and rapidly constructed using the AdEasy system.展开更多
Phosphatase and tensin homolog deleted on chromosome 10（PTEN） and the proliferating antigen Ki67 have been widely studied in several tumors.However,their role as indicator in non-small cell lung cancer（NSCLC）remai...Phosphatase and tensin homolog deleted on chromosome 10（PTEN） and the proliferating antigen Ki67 have been widely studied in several tumors.However,their role as indicator in non-small cell lung cancer（NSCLC）remains unknown.Here,we investigated the expression of PTEN and Ki67 in NSCLC tissues and paired normal lung tissues to identify whether these proteins are associated with lung cancer development and survival.Immunohistochemistry for PTEN and Ki67 was performed on 67 lung cancer tissues and 41 paired adjacent normal lung tissues to detect the expression of these two proteins.The expression of PTEN in NSCLC tissues（32.8%） was significantly lower than that in normal tissues（82.9%,P 〈 0.05）.In contrast,the expression of Ki67 in NSCLC tissues（76.1%） was significantly higher than that in normal tissues（27.3%,P 〈 0.05）.Expression of both PTEN and Ki67 were strongly associated with tumor histology,clinical stage,lymph node metastasis,differentiation and4-year postoperative survival rate（P 〈 0.05）.However,PTEN expression was negatively correlated with Ki67 expression（r =-0.279,P 〈 0.05）.In conclusion,low PTEN expression and Ki67 overexpression are associated with malignant invasion and lymph node metastasis of NSCLC.These proteins may serve as diagnostic and prognostic biomarkers of NSCLC.展开更多
Recently,phosphatase and tensin homolog deleted on chromosome 10（PTEN） is suggested as a new agent in the fighting against fibrogenesis.In tumor,DJ-1 is identified as a negative regulator of PTEN.But the expression ...Recently,phosphatase and tensin homolog deleted on chromosome 10（PTEN） is suggested as a new agent in the fighting against fibrogenesis.In tumor,DJ-1 is identified as a negative regulator of PTEN.But the expression of DJ-1 and the regulation of PTEN in fibrosis are unclear.Renal fibrosis was induced in 5/6 subtotal nephrectomy rat model.Human proximal tubular epithelial cells（HKC） were treated with transforming growth factor-beta 1（TGF-β1）,or transfected with DJ-1 or PTEN.Confocal microscope was used to investigate the localization of DJ-1 and PTEN.The selective phosphoinositide-3 kinase（PI3K） inhibitor,LY294002,was administered to inhibit PI3K pathway.The DJ-1 and PTEN expression,markers of epithelial-mesenchymal transition（EMT） and Akt phosphorylation were measured by RT-PCR,Western blotting or immunocytochemistry.In vitro,after HKC cells were stimulated with 10 ng/mL TGF-β1 for 72 h,the expression of DJ-1 was increased,and that of PTEN was decreased.In vivo,the same results were identified in 5/6-nephrectomized rats.In normal HKC cells,most of DJ-1 protein localized in cytoplasm,and little in nucleus.TGF-β1 upregulated DJ-1 expression in both cytoplasma and nuclei.In contrary,TGF-β1 emptied cytoplasmic PTEN protein into nucleus.Overexpression of DJ-1 decreased the expression of PTEN,promoted the activation of Akt and the expression of vimentin,and also led to the loss of cytoplasmic PTEN.Contrarily,overexpression of PTEN protected HKC cells from TGF-β1-induced EMT.In conclusion,DJ-1 is upregulated in renal fibrosis and DJ-1 mediates EMT by suppressing cytoplasmic PTEN expression and Akt activation.展开更多
Objective:To study whether miR-200a and miR-200b target PTEN gene expression to regulate the endometrial cancer cell growth in vitro. Methods:Endometrial cancer cells ECC-1 were cultured and transfected with the miR-2...Objective:To study whether miR-200a and miR-200b target PTEN gene expression to regulate the endometrial cancer cell growth in vitro. Methods:Endometrial cancer cells ECC-1 were cultured and transfected with the miR-200a and miR-200b mimics and inhibitors as well as the negative control mimics and inhibitors,and then the cell proliferation activity as well as the expression of PTEN and downstream genes in cells was determined; after transfection of miR-200a and miR-200b mimics as well as PTEN-3'UTR luciferase report gene plasmids,the fluorescence activity of luciferase reporter gene was determined. Results:12 h,24 h and 48 h after transfection,the cell proliferation activity of miR-200a mimics group and miR-200b mimics group were significantly higher than those of NC mimics group while the cell proliferation activity of mi R-200 a inhibitor group and miR-200b inhibitor group were significantly lower than those of NC inhibitor group; 48 h after transfection,PTEN expression in cells and PTEN-3'UTR luciferase reporter gene fluorescence activity of miR-200 a mimics group and miR-200b mimics group were significantly lower than those of NC mimics group while p-PI3K and p-Akt expression were significantly higher than those of NC mimics group; PTEN expression in cells and PTEN-3'UTR luciferase reporter gene fluorescence activity of miR-200 inhibitor group and miR-200b inhibitor group were significantly higher than those of NC inhibitor group while p-PI3K and p-Akt expression were significantly lower than those of NC inhibitor group. Conclusion:miR-200 a and miR-200b can promote the endometrial cancer cell growth in vitro by targeted inhibition of PTEN gene expression.展开更多
AIM:To investigate the regulative effect of miRNA(miR)-221 on colorectal carcinoma(CRC)cell radiosensitivity and the underlying mechanisms.METHODS:A human CRC-derived cell line was cultured conventionally and exposed ...AIM:To investigate the regulative effect of miRNA(miR)-221 on colorectal carcinoma(CRC)cell radiosensitivity and the underlying mechanisms.METHODS:A human CRC-derived cell line was cultured conventionally and exposed to different doses of X-rays(0,2,4,6 and 8 Gy).The total RNA and protein of the cells were extracted 24 h after irradiation,and the alteration of miR-221 and phosphatase and tensin homolog deleted on chromosome 10(PTEN)gene mRNA expression was detected by real-time reverse transcriptase polymerase chain reaction(PCR).The protein alteration of PTEN in the cells was detected by Western blotting.Caco2 cells were pretreated with or without anti-PTEN-siRNA prior to the addition of premiR-221 or anti-miR-221 using Lipofectamine 2000.Colony formation assay and flow cytometry analysis were used to measure the surviving cell fraction and the sensitizing enhancement ratio after irradiation.Ad-ditionally,PTEN 3′-untranslated region fragment was PCR amplified and inserted into a luciferase reporter plasmid.The luciferase reporter plasmid construct was then transfected into CRC cells together with premiR-221 or anti-miR-221,and the luciferase activity in the transfected cells was detected.RESULTS:The X-ray radiation dose had a significant effect on the expression of miR-221 and PTEN protein in human Caco2 cells in a dose-dependent manner.The miR-221 expression level improved gradually with the increase in irradiation dose,while the PTEN protein expression level reduced gradually.miR-221 expression was significantly reduced in the anti-miR-221 group compared with the pre-miR-221 and negative control groups(P<0.01).Anti-miR-221 upregulated expression of PTEN protein and enhanced the radiosensitivity of Caco2 cells(P<0.01).Moreover,the inhibitory effect was dramatically abolished by pretreatment with anti-PTEN-siRNA,suggesting that the enhancement of radiosensitivity was indeed mediated by PTEN.A significant increase of luciferase activity was detected in CRC cells that were cotransfected with the luciferase reporter plasmid construct and anti-miR-221(P<0.01).CONCLUSION:Anti-miR-221 can enhance the radiosensitivity of CRC cells by upregulating PTEN.展开更多
AIM:To investigate the effects of phosphatase and tensin homolog deleted on chromosome 10(PTEN) deficiency on the cytotoxicity of chemotherapeutic agents toward colorectal cancer cells.METHODS:PTEN-deficient colorecta...AIM:To investigate the effects of phosphatase and tensin homolog deleted on chromosome 10(PTEN) deficiency on the cytotoxicity of chemotherapeutic agents toward colorectal cancer cells.METHODS:PTEN-deficient colorectal cancer(CRC) cells were generated by human somatic cell gene targeting using the adeno-associated virus system. The cytotoxic effects of compounds including curcumin,5-fluorouracil(5-FU),dihydroartemisinin(DHA),irinotecan(CPT-11)and oxaliplatin(OXA) on cancer cells were determined using the MTT assay. Enhanced cytotoxicity of curcumin in PTEN-deficient CRC cells was observed,and this was confirmed using clonogenic assays. Apoptosis and cell cycle progression were analyzed by flow cytometry.Levels of apoptosis and cell cycle-related proteins were examined by Western blotting.RESULTS:We developed an isogenic set of CRC cell lines that differed only in their PTEN status. Using this set of cell lines,we found that disruption of the PTEN gene had no effect on the sensitivity of CRC cells to5-FU,CPT-11,DHA,or OXA,whereas PTEN disruption increased the sensitivity of CRC cells to curcumin. Loss of PTEN did not alter the curcumin-induced apoptosis in CRC cells. However,PTEN deficiency led to an altered pattern of curcumin-mediated cell cycle arrest.In HCT116 PTEN+/+cells,curcumin caused a G2/M phase arrest,whereas it caused a G0/G1 phase arrest in HCT116 PTEN-/-cells. Levels of cell cycle-related proteins were consistent with these respective patterns of cell cycle arrest.CONCLUSION:Curcumin shows enhanced cytotoxicity toward PTEN-deficient cancer cells,suggesting that it might be a potential chemotherapeutic agent for cancers harboring PTEN mutations.展开更多
Background： Apoptosis of endothelial cells （ECs） plays a key role in the development of atherosclerosis and there are also evidence indicated that phosphatase and tensin homolog deleted on chromosome 10 （PTEN） is...Background： Apoptosis of endothelial cells （ECs） plays a key role in the development of atherosclerosis and there are also evidence indicated that phosphatase and tensin homolog deleted on chromosome 10 （PTEN） is a viable target in therapeutic approaches to prevent vascular ECs apoptosis. Aberrant miR-106b-5p expression has been reported in the plasma of patients with unstable atherosclerotic plaques. However, the role and underlying mechanism of miR-106-5p in the genesis of atherosclerosis have not been addressed. In this study, we explored the anti-apoptotic role of miR-106-5p by regulating PTEN expression in vascular ECs. Methods： Real-time reverse transcription polymerase chain reaction （RT-PCR） was performed to detect the expression levels of miR-106b-5p in human atherosclerotic plaques and normal vascular tissues. Human umbilical vein endothelial cells （HUVEC） were transfected with miR-106b-5p mimic or negative control mimic, and apoptosis was induced by serum starvation and tumor necrosis factor-α （TN F-α） treat. Western blotting and real-time RT-PCR experiments were used to detect PTEN expression levels and TN F-α-induced apoptosis was evaluated by the activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Results： The expression ofmiR-106b-5p was significantly downregulated in plaques than in normal vascular tissues. TNF-α significantly downregulated miR-106b-5p expression levels and upregulated activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Overexpression ofmiR-106b-5p with miR-106b-5p mimic inhibited PTEN expression and TNF-α-induced apoptosis in HUVEC. Luciferase reporter assays confirmed that miR-106b-5p binds to PTEN mRNA 3＇ untranslated region site, Conclusion： MiR-106b-5p could inhibit the expression of PTEN in vascular ECs, which could block TNF-α-induced activation of caspase-3, thus prevent ECs apoptosis in atherosclerosis diseases.展开更多
人第10号染色体缺失的磷酸酶及张力蛋白同源(phosphatase and tensin homolog deleted on chromosome ten,PTEN)基因作为一种抑癌基因,在调控肿瘤方面的作用广为人知。近年来研究发现,PTEN除了在肿瘤防治上发挥作用外,还能通过抑制炎症...人第10号染色体缺失的磷酸酶及张力蛋白同源(phosphatase and tensin homolog deleted on chromosome ten,PTEN)基因作为一种抑癌基因,在调控肿瘤方面的作用广为人知。近年来研究发现,PTEN除了在肿瘤防治上发挥作用外,还能通过抑制炎症、氧化应激的发展来减缓动脉粥样硬化(atherosclerosis,AS)的进程。同时,PTEN蛋白能够抑制AS中血管平滑肌细胞(vascular smooth muscle cells,VSMCs)的异常增殖,以及调控巨噬细胞极化的方向、改变巨噬细胞表面清道夫受体的类型来抗AS。而PTEN对于血管内皮细胞(vascular endothelial cells,VECs)的调控则具有双重性。文章对PTEN的结构、功能与发挥的调控作用做一简要综述,以期为AS防治的基础研究提供新的思路和靶点。展开更多
文摘To examine phosphatase and tensin homology deleted in chromosome 10 (PTEN),hypoxia-inducible factor-1 alpha (HIF-1 alpha) gene expressions and their relation to vascular endothelial growth factor(VEGF) protein expression in the patients with human colorectal adenomas and adenocarcinomas.Methods The expression of PTEN,HIF-1 alpha gene was detected by using in situ hybridization,and the VEGF expression levels by immunohistochemistry in colorectal adenomas and primary colorectal adenocarcinoma.Results Strong expression of HIF-1 alpha was detectable in the majority of colorectal dadenocarcinoma,particularly surrounding areas of necrosis in adenocarcinoma.PTEN,HIF-1 alpha mRNA and VEGF protein were positive in 51.6%,67.7% and 59.7% respectively in 62 cases of adenocarcinomas,and 77.8%,44.4% and 33.3% respectively in 18 cases of adenomas.The positive rate of VEGF was higher in the patients with colorectal adenocarcinomas than that in those with adenomas,whereas that of PTEN mRNA was contrary.HIF-1 mRNA expression was correlated significantly with lymph node metastasis,liver metastasis,Duke’s stage and recurrence.During colorectal tumor progression,the expression of HIF-1 alpha mRNA was positively correlated with the VEGF protein expression (χ2= 4.751 ,P<0.05),but negatively with the PTEN mRNA expression(χ2=21.84,P<0.01).Conclusion The absence or low expression of PTEN and the increased levels of HIF-1α and VEGF may paly an important role in carcinogenesis and progression of colorectal carcinoma.These results suggest that VEGF upregulated by HIF-1 alpha gene may be involved in angiogenesis of colorectal adenocarcinoma.4 refs,1 tab.
文摘Recent studies have shown that phosphatase and tensin homolog-deleted on chromosome ten （PTEN） gene plays an important role in ischemic brain damage and synaptic plasticity. The AdEasy system, which has been widely used, greatly simplifies preparation of recombinant adenovirus. Therefore, recombinant defective adenovirus vector carrying human PTEN tumor suppressor gene （Ad-PTEN） was constructed using the AdEasy-1 system and was transfected into HEK293 cells for packaging and amplification. Infection efficiency and expression intensity were observed in primary cultured rat hippocampal neurons infected with Ad-PTEN in vitro. Results revealed a cytopathic effect in green fluorescent protein expression, which increased with prolonged time. After three cycles of amplification, the adenovirus titer was increased to an adequate titer for infecting hippocampal neurons. The entire process typically requires 4-5 weeks for completion. Results suggested that recombinant defective adenovirus vector carrying the PTEN gene was successfully and rapidly constructed using the AdEasy system.
基金supported by Nanjing Medical University Focus Development and Natural Science Foundation of China
文摘Phosphatase and tensin homolog deleted on chromosome 10（PTEN） and the proliferating antigen Ki67 have been widely studied in several tumors.However,their role as indicator in non-small cell lung cancer（NSCLC）remains unknown.Here,we investigated the expression of PTEN and Ki67 in NSCLC tissues and paired normal lung tissues to identify whether these proteins are associated with lung cancer development and survival.Immunohistochemistry for PTEN and Ki67 was performed on 67 lung cancer tissues and 41 paired adjacent normal lung tissues to detect the expression of these two proteins.The expression of PTEN in NSCLC tissues（32.8%） was significantly lower than that in normal tissues（82.9%,P 〈 0.05）.In contrast,the expression of Ki67 in NSCLC tissues（76.1%） was significantly higher than that in normal tissues（27.3%,P 〈 0.05）.Expression of both PTEN and Ki67 were strongly associated with tumor histology,clinical stage,lymph node metastasis,differentiation and4-year postoperative survival rate（P 〈 0.05）.However,PTEN expression was negatively correlated with Ki67 expression（r =-0.279,P 〈 0.05）.In conclusion,low PTEN expression and Ki67 overexpression are associated with malignant invasion and lymph node metastasis of NSCLC.These proteins may serve as diagnostic and prognostic biomarkers of NSCLC.
基金supported by a grant from National Natural Sciences Foundation of China (No. 30800525)
文摘Recently,phosphatase and tensin homolog deleted on chromosome 10（PTEN） is suggested as a new agent in the fighting against fibrogenesis.In tumor,DJ-1 is identified as a negative regulator of PTEN.But the expression of DJ-1 and the regulation of PTEN in fibrosis are unclear.Renal fibrosis was induced in 5/6 subtotal nephrectomy rat model.Human proximal tubular epithelial cells（HKC） were treated with transforming growth factor-beta 1（TGF-β1）,or transfected with DJ-1 or PTEN.Confocal microscope was used to investigate the localization of DJ-1 and PTEN.The selective phosphoinositide-3 kinase（PI3K） inhibitor,LY294002,was administered to inhibit PI3K pathway.The DJ-1 and PTEN expression,markers of epithelial-mesenchymal transition（EMT） and Akt phosphorylation were measured by RT-PCR,Western blotting or immunocytochemistry.In vitro,after HKC cells were stimulated with 10 ng/mL TGF-β1 for 72 h,the expression of DJ-1 was increased,and that of PTEN was decreased.In vivo,the same results were identified in 5/6-nephrectomized rats.In normal HKC cells,most of DJ-1 protein localized in cytoplasm,and little in nucleus.TGF-β1 upregulated DJ-1 expression in both cytoplasma and nuclei.In contrary,TGF-β1 emptied cytoplasmic PTEN protein into nucleus.Overexpression of DJ-1 decreased the expression of PTEN,promoted the activation of Akt and the expression of vimentin,and also led to the loss of cytoplasmic PTEN.Contrarily,overexpression of PTEN protected HKC cells from TGF-β1-induced EMT.In conclusion,DJ-1 is upregulated in renal fibrosis and DJ-1 mediates EMT by suppressing cytoplasmic PTEN expression and Akt activation.
基金supported by Natural Science Foundation of China(No.39770176)National Science Fund for Distinguished Young Scholars(No.39925012)
文摘Objective:To study whether miR-200a and miR-200b target PTEN gene expression to regulate the endometrial cancer cell growth in vitro. Methods:Endometrial cancer cells ECC-1 were cultured and transfected with the miR-200a and miR-200b mimics and inhibitors as well as the negative control mimics and inhibitors,and then the cell proliferation activity as well as the expression of PTEN and downstream genes in cells was determined; after transfection of miR-200a and miR-200b mimics as well as PTEN-3'UTR luciferase report gene plasmids,the fluorescence activity of luciferase reporter gene was determined. Results:12 h,24 h and 48 h after transfection,the cell proliferation activity of miR-200a mimics group and miR-200b mimics group were significantly higher than those of NC mimics group while the cell proliferation activity of mi R-200 a inhibitor group and miR-200b inhibitor group were significantly lower than those of NC inhibitor group; 48 h after transfection,PTEN expression in cells and PTEN-3'UTR luciferase reporter gene fluorescence activity of miR-200 a mimics group and miR-200b mimics group were significantly lower than those of NC mimics group while p-PI3K and p-Akt expression were significantly higher than those of NC mimics group; PTEN expression in cells and PTEN-3'UTR luciferase reporter gene fluorescence activity of miR-200 inhibitor group and miR-200b inhibitor group were significantly higher than those of NC inhibitor group while p-PI3K and p-Akt expression were significantly lower than those of NC inhibitor group. Conclusion:miR-200 a and miR-200b can promote the endometrial cancer cell growth in vitro by targeted inhibition of PTEN gene expression.
基金Supported by National Natural Science Foundation of China,No.81101896the National Research Foundation for Doctoral Program of Higher Education of China,No.20124433110010
文摘AIM:To investigate the regulative effect of miRNA(miR)-221 on colorectal carcinoma(CRC)cell radiosensitivity and the underlying mechanisms.METHODS:A human CRC-derived cell line was cultured conventionally and exposed to different doses of X-rays(0,2,4,6 and 8 Gy).The total RNA and protein of the cells were extracted 24 h after irradiation,and the alteration of miR-221 and phosphatase and tensin homolog deleted on chromosome 10(PTEN)gene mRNA expression was detected by real-time reverse transcriptase polymerase chain reaction(PCR).The protein alteration of PTEN in the cells was detected by Western blotting.Caco2 cells were pretreated with or without anti-PTEN-siRNA prior to the addition of premiR-221 or anti-miR-221 using Lipofectamine 2000.Colony formation assay and flow cytometry analysis were used to measure the surviving cell fraction and the sensitizing enhancement ratio after irradiation.Ad-ditionally,PTEN 3′-untranslated region fragment was PCR amplified and inserted into a luciferase reporter plasmid.The luciferase reporter plasmid construct was then transfected into CRC cells together with premiR-221 or anti-miR-221,and the luciferase activity in the transfected cells was detected.RESULTS:The X-ray radiation dose had a significant effect on the expression of miR-221 and PTEN protein in human Caco2 cells in a dose-dependent manner.The miR-221 expression level improved gradually with the increase in irradiation dose,while the PTEN protein expression level reduced gradually.miR-221 expression was significantly reduced in the anti-miR-221 group compared with the pre-miR-221 and negative control groups(P<0.01).Anti-miR-221 upregulated expression of PTEN protein and enhanced the radiosensitivity of Caco2 cells(P<0.01).Moreover,the inhibitory effect was dramatically abolished by pretreatment with anti-PTEN-siRNA,suggesting that the enhancement of radiosensitivity was indeed mediated by PTEN.A significant increase of luciferase activity was detected in CRC cells that were cotransfected with the luciferase reporter plasmid construct and anti-miR-221(P<0.01).CONCLUSION:Anti-miR-221 can enhance the radiosensitivity of CRC cells by upregulating PTEN.
基金Supported by The National Natural Science Foundation of China,No.81101472 to Liao WQNo.31071086 to Lu XC
文摘AIM:To investigate the effects of phosphatase and tensin homolog deleted on chromosome 10(PTEN) deficiency on the cytotoxicity of chemotherapeutic agents toward colorectal cancer cells.METHODS:PTEN-deficient colorectal cancer(CRC) cells were generated by human somatic cell gene targeting using the adeno-associated virus system. The cytotoxic effects of compounds including curcumin,5-fluorouracil(5-FU),dihydroartemisinin(DHA),irinotecan(CPT-11)and oxaliplatin(OXA) on cancer cells were determined using the MTT assay. Enhanced cytotoxicity of curcumin in PTEN-deficient CRC cells was observed,and this was confirmed using clonogenic assays. Apoptosis and cell cycle progression were analyzed by flow cytometry.Levels of apoptosis and cell cycle-related proteins were examined by Western blotting.RESULTS:We developed an isogenic set of CRC cell lines that differed only in their PTEN status. Using this set of cell lines,we found that disruption of the PTEN gene had no effect on the sensitivity of CRC cells to5-FU,CPT-11,DHA,or OXA,whereas PTEN disruption increased the sensitivity of CRC cells to curcumin. Loss of PTEN did not alter the curcumin-induced apoptosis in CRC cells. However,PTEN deficiency led to an altered pattern of curcumin-mediated cell cycle arrest.In HCT116 PTEN+/+cells,curcumin caused a G2/M phase arrest,whereas it caused a G0/G1 phase arrest in HCT116 PTEN-/-cells. Levels of cell cycle-related proteins were consistent with these respective patterns of cell cycle arrest.CONCLUSION:Curcumin shows enhanced cytotoxicity toward PTEN-deficient cancer cells,suggesting that it might be a potential chemotherapeutic agent for cancers harboring PTEN mutations.
基金This research was funded by the National Natural Science Foundation of China (NSFC)
文摘Background： Apoptosis of endothelial cells （ECs） plays a key role in the development of atherosclerosis and there are also evidence indicated that phosphatase and tensin homolog deleted on chromosome 10 （PTEN） is a viable target in therapeutic approaches to prevent vascular ECs apoptosis. Aberrant miR-106b-5p expression has been reported in the plasma of patients with unstable atherosclerotic plaques. However, the role and underlying mechanism of miR-106-5p in the genesis of atherosclerosis have not been addressed. In this study, we explored the anti-apoptotic role of miR-106-5p by regulating PTEN expression in vascular ECs. Methods： Real-time reverse transcription polymerase chain reaction （RT-PCR） was performed to detect the expression levels of miR-106b-5p in human atherosclerotic plaques and normal vascular tissues. Human umbilical vein endothelial cells （HUVEC） were transfected with miR-106b-5p mimic or negative control mimic, and apoptosis was induced by serum starvation and tumor necrosis factor-α （TN F-α） treat. Western blotting and real-time RT-PCR experiments were used to detect PTEN expression levels and TN F-α-induced apoptosis was evaluated by the activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Results： The expression ofmiR-106b-5p was significantly downregulated in plaques than in normal vascular tissues. TNF-α significantly downregulated miR-106b-5p expression levels and upregulated activation of caspase-3 and cell DNA fragmentation levels in HUVEC. Overexpression ofmiR-106b-5p with miR-106b-5p mimic inhibited PTEN expression and TNF-α-induced apoptosis in HUVEC. Luciferase reporter assays confirmed that miR-106b-5p binds to PTEN mRNA 3＇ untranslated region site, Conclusion： MiR-106b-5p could inhibit the expression of PTEN in vascular ECs, which could block TNF-α-induced activation of caspase-3, thus prevent ECs apoptosis in atherosclerosis diseases.
