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1.
AIM:To explore the function of miR-21 in human glioma cells resistant to carmustine and to elucidate its related mechanism. METHODS:SWOZ2 cells were transfected with miR-21 mimics(SWOZ2-miR-21mimics) or miRNA mimics negative control(control group) by the method of jetPRIME. The real-time fluorescence quantitative PCR was used to detect and compare the levels of miR-21 expression between BCNU-resistant cell line SWOZ2-BCNU and BCNU-sensitive cell line SWOZ2, or between SWOZ2-miR-21 mimic group and control group. The drug sensitivity of these cells to BCNU was determined by CCK-8 assay. The protein expression of phosphatase and tensin homology deleted on chromosome 10(PTEN), phosphorylated protein kinase B(p-Akt) and P-glycoprotein(P-gp) in these cells were also detected by Western blotting. RESULTS:The expression level of miR-21 was remarkably higher in SWOZ2-BCNU cells than that in SWOZ2 cells. The expression level of miR-21 was significantly higher in SWOZ2-miR-21 mimics group than that in control group. The half-maximal inhibitory concentration(IC50) of BCNU was obviously higher for SWOZ2-BCNU cells than that for SWOZ2 cells. The IC50 of BCNU was markedly higher in SWOZ2-miR-21 mimics group than that in control group. PTEN protein expression was remarkably lower, but p-Akt and P-gp protein expression levels were markedly higher in SWOZ2-BCNU cells than those in SWOZ2 cells. The protein level of PTEN was significantly lower, but the protein levels of p-Akt or P-gp were distinctly higher in SWOZ2-miR-21 mimics group than those in control group. CONCLUSION:miR-21 enhances the resistance of human glioma cells to BCNU by down-regulating the expression of PTEN protein.  相似文献   

2.
AIM: To investigate the molecular mechanism of microRNA-1246(miR-1246) enhancing radiosensitivity of cervical cancer cells. METHODS: Cervical cancer lines HeLa, CaSki, C33A and SiHa were transfected with miR-1246 mimic and negative control mimic (NC-mimic) using Lipofectamine 2000 kit, and the expression level of miR-1246 in cervical cancer tissue, normal tissue, cervical cancer cell lines and endometrial epithelium cell line ESC was detected by real-time PCR. The transfected cells were exposed to X-ray radiation. The cell viability and migration rate were measured respectively by MTT assay and Transwell method. The protein levels of γH2AX, ATM, p-ATM and p-p53 were monitored by immunofluorescence and Western blot. RESUITS: Higher miR-1246 level was found in normal tissue and ESC cells, while lower miR-1246 level was found in HeLa, SiHa, C33A and Caski cells and cervical cancer tissues. The expression level of miR-1246 in the cells transfected with miR-1246 mimic was significantly higher than that in the cells transfected with NC-mimic (P<0.05). The cell viability and migration rate of the cervical cancer cells with miR-1246 over-expression were notably lower than those of the cells transfected with NC-mimic (P<0.05) under the same conditions. The results of immunofluorescence indicated that the protein expression level of γH2AX significantly increased in the cervical cancer cells with miR-1246 over-expression exposed to radiation compared with the negative control (P<0.05). The protein expression level of γH2AX was significantly increased in the cervical cancer cells with miR-1246 over-expression, while the protein levels of p-ATM and p-p53 were significantly decreased as compared with the negative control group (P<0.05). CONCLUSION: miR-1246 is highly expressed in normal tissue and normal endometrial epithelial cells, while is low expressed in the cervical cancer tissues or cells. miR-1246 over-expression inhibits growth and migration, and significantly enhances radiosensitivity of cervical cancer cells. The molecular mechanism is possibly related to inhibiting ATM pathway and DNA damage repair.  相似文献   

3.
AIM:To observe the effects of shikonin on the apoptosis and autophagy of human cervical cancer HeLa cells, and to explore the possible role of PI3K/Akt/mTOR signaling pathway in these processes. METHODS:The HeLa cells were treated with shikonin, and the cell viability was detected by CCK-8 assay. The apoptosis was detected by Annexin V/PI double staining. The autophagosome was observed by transfection with GFP-LC3 into the HeLa cells. After the treatment with shikonin combined with autophagy inhibitor 3-methyladenine (3-MA) or apoptosis inhibitor Z-DEVD-FMK, the protein levels of autophagy-and apoptosis-related molecules microtuble-associated protein 1 light chain 3 (LC3) and cleaved caspase-3 in the HeLa cells were determined by Western blot. The protein levels of phosphorylated PI3K (p-PI3K), phosphorylated Akt (p-Akt) and phosphorylated mTOR (p-mTOR) were also determined by Western blot. RESULTS:Shikonin significantly inhibited the viability of HeLa cells (P<0.05). Compared with control group, shikonin significantly induced apoptosis of HeLa cells (P<0.05). The results of GFP-LC3 plasmid transfection analysis showed that green dot-like congregate autophagosomes appeared in the cytoplasm of the HeLa cells after shikonin treatment, while the autophagosomes were rarely observed in control group. Compared with shikonin group, LC3-Ⅱ/LC3-I was significantly decreased and cleaved caspase-3 was significantly increased in shikonin+3-MA group (P<0.05). Compared with shikonin group, LC3-Ⅱ/LC3-I was significantly increased and cleaved caspase-3 was significantly decreased in shikonin+Z-DEVD-FMK group (P<0.05). Compared with control group, shikonin significantly decreased the protein levels of p-PI3K, p-Akt and p-mTOR (P<0.05). CONCLUSION:The apoptosis and autophagy of the HeLa cells are induced by shikonin, these two processes are complementary. The mechanism may be related to inhibition of PI3K/Akt/mTOR signaling pathway.  相似文献   

4.
AIM: To investigate the effect of wild-type PTEN transfection on the sensitivity of human leukemia K562 cells to artesunate (ART) and its molecular mechanism. METHODS: The adenovirus containing wild-type PTEN (Ad-WT-PTEN) or empty vectors (Ad) were transfected into K562 cells[with multiplicity of infection (MOI)=200]. The untransfected cells served as normal control. The effect of wild-type PTEN on the inhibition of K562 cell growth by ART was observed. The sensitizing ratio of PTEN combined with ART based on IC50 was calculated. The viability of K562 cells was detected by MTT assay. The apoptosis was analyzed by flow cytometry. The mRNA level of PTEN was assessed by real-time PCR. The protein expression of PTEN, p-Akt and Akt was detected by Western blot. The activity of caspase-3/7 was measured by caspase activity kits. RESULTS: The sensitivity of K562 cells to ART was significantly increased by 2.25 folds after transfected with PTEN based on the IC50. The cell viability in Ad-WT-PTEN+ART group was significantly lower than that in Ad+ART group after transfection for 3 d (P<0.01). The apoptotic rate in Ad-WT-PTEN+ART group was significantly higher than that in Ad+ART group (P<0.01). The expression of PTEN at mRNA and protein levels in the K562 cells after transfection with PTEN was significantly increased, and the protein level of p-Akt and caspase-3/7 activity were down-regulated, particularly in PTEN combined with ART group. CONCLUSION: The wild-type PTEN gene enhances the sensitivity of the K562 cells to ART by down-regulating the level of p-Akt and up-regulating the caspase-3/7 activity.  相似文献   

5.
AIM:To investigate the down-regulation of phosphatase and tensin homolog deleted on chromosome 10(PTEN) gene by adenovirus-mediated short hairpin RNA(shRNA) on proliferation and apoptosis of activated hepatic stellate cells(HSCs) in vitro and the related signaling transduction pathways. METHODS:The activated HSCs were cultured in vitro and transfected with recombinant adenovirus expressing shRNA targeting PTEN. The proliferation of HSCs was measured by MTT assay and the apoptosis was assessed by TUNEL and flow cytometry. Western blotting was used to detect the protein levels of PTEN, Bax, Bcl-2, Akt, p-Akt, ERK1/2 and p-ERK1/2 in HSCs, and real-time fluorescent quantitative PCR was applied to detect the mRNA expression of Akt and ERK1. RESULTS:The recombinant adenovirus expressing shRNA targeting PTEN was successfully transfected into activated HSCs in vitro, and significantly promoted the proliferation of HSCs in a time-dependent manner within a certain extent. The apoptotic rate of HSCs was significantly decreased 72 h after transfection(P<0.05). Meanwhile, reduced expression of Bax and elevated expression of Bcl-2 were induced 72 h after transfection(P<0.05). Furthermore, the expression of p-Akt and p-ERK1/2 were increased significantly(P<0.05), while no significant difference in the expression of Akt and ERK1 at mRNA and protein levels was observed(P>0.05). CONCLUSION:Down-regulation of PTEN by adenovirus-mediated shRNA dramatically promotes the proliferation of activated HSCs, and inhibits the apoptosis through Bcl-2/Bax pathway. In addition, the phosphorylation of Akt and ERK1/2 is increased, indicating that PI3K/Akt and ERK1/2 signal transduction pathways may play an important role in the regulation of proliferation and apoptosis of HSCs.  相似文献   

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7.
AIM: To explore the effect of microRNA-221 (miR-221) on resistance of lung cancer cells to gefitinib, and to investigate its related mechanism. METHODS: RT-qPCR was used to detect the levels of miR-221 expression between gefitinib-sensitive cell line PC9 and gefitinib-resistant cell line PC9/GR. The PC9/GR cells were transfected with miR-221 inhibitor by Lipofectamine 2000. The drug sensitivity of these cells to gefitinib was determined by CCK-8 assay. The protein expression level of phosphatase and tensin homologue deleted on chromosome ten (PTEN) was determined by Western blot. The 3'-UTR of PTEN was cloned into luciferase reporter vector and its luciferase activity was detected to verify whether miR-221 targets PTEN. RESULTS: The expression level of miR-221 in the PC9/GR cells was significantly higher than that in the PC9 cells (P<0.05). The protein expression level of PTEN in the PC9/GR cells was lower than that in the PC9 cells (P<0.05). The IC50 of gefitinib was significantly reduced in the PC9/GR cells after transfection with miR-221 inhibitor (P<0.05). The protein expression level of PTEN in the cells transfected with miR-221 inhibitor was increased as compared with control group and blank group (P<0.05). Inhibition of miR-221 expression enhanced the enzymatic activity of luciferase reporter vector of PTEN. CONCLUSION: miR-221 enhances the resistance of lung cancer cells to gefitinib by down-regulating the protein expression of PTEN.  相似文献   

8.
AIM: To investigate the effect of naringin (NRG) on cisplatin (DDP) resistance in human lung cancer A549/DDP cells and its possible mechanism. METHODS: A549/DDP cells were cultured in vitro and treated with NRG and/or DDP at different concentrations for 24 h, and then the cell viability were measured by CCK-8 assay. The combination index (CI) of NRG and DDP were analyzed by Chou-Talalay method. The apoptosis rate was analyzed by flow cytometry. Western blot was performed to detect the protein levels of P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1), p-Akt, CXC chemokine receptor 4 (CXCR4), cleaved caspase-3, Bcl-2 and Bax.RESULTS: The protein levels of P-gp, MRP1, p-Akt and CXCR4 in the A549/DDP cells were higher than those in the A549 cells (P<0.05). The cell viability was remarkably reduced in a dose-dependent manner when A549/DDP cells were exposed to NRG and/or DDP (P<0.05), and the IC50 values of NRG and DDP were 36.92 μmol/L and 129.77 μmol/L, respectively. When the inhibition rate exceeded 15%, NRG in combination with DDP produced a synergistic effect (CI<1). Combination treatment with NRG and DDP significantly induced apoptosis (P<0.05), up-regulated the protein levels of cleaved caspase-3 and Bax, and down-regulated the protein level of Bcl-2 (P<0.05). Meanwhile, NRG remarkably down-regulated the protein levels of P-gp, MRP1, p-Akt and CXCR4 in a dose-dependent manner (P<0.05). CONCLUSION: NRG may enhance the sensibility of A549/DDP cells to DDP most likely via up-regulating the protein level of Bax and down-regulating the protein levels of Bcl-2, P-gp, MRP1, p-Akt and CXCR4.  相似文献   

9.
AIM: To explore the protective effect of fasudil hydrochloride against cisplatin(CP)-induced renal tubular epithelial cell apoptosis via Akt activation and PTEN inhibition. METHODS: Healthy male Sprague-Dawley (SD) rats were randomly divided into control group, CP group and CP+ fasudil group. All animals were sacrificed 96 h after injection of 0.9% saline or CP. Blood samples and kidney tissues were collected to evaluate levels of blood urea nitrogen (BUN), serum creatinine (sCr) and morphological alteration of the kidneys, respectively. The apoptosis of renal tubular epithelium cells was detected by TUNEL. Protein levels of Rho-associated protein kinase 1 (ROCK1), PTEN and Akt were measured by Western blotting and immunohistochemistry. The protein level of p-Akt was analyzed by Western blotting. RESULTS: Compared with control group, the sCr and BUN levels, the expression of ROCK1 and PTEN and TUNEL-positive cells were increased, while the level of p-Akt was decreased in CP group and CP+fasudil group. The histological structure of the kidneys observed by PAS staining was developed marked structural damage in CP group(P<0.05). Compared with CP group, sCr level, the expression of ROCK1 and PTEN and TUNEL-positive cells were decreased, while the level of p-Akt was increased in CP+fasudil group (P<0.05). Very little structural damage was detected in fasudil-treated groups. CONCLUSION: Fasudil hydrochloride has a protective effect on CP-induced renal tubular epithelial cell apoptosis via Akt activation and PTEN inhibition 1.  相似文献   

10.
AIM: To observe the expression of Akt/GSK-3β/Snail signaling pathway-related molecules in cisplatin-resistant cell line A549/DDP mediated by transforming growth factor-β1 (TGF-β1), and to explore the association of Akt/GSK-3β/Snail signaling pathway with epithelial-mesenchymal transition (EMT). METHODS: The A549/DDP cells were divided into TGF-β1 (+) group, TGF-β1 (-) group and LY294002 group. The morphological changes of A549/DDP cells treated with TGF-β1 were observed under microscope. The protein expression of E-cadherin and N-cadherin was determined by the methods of immumofluorescence and Western blot. The protein levels of Akt, p-Akt, GSK-3β, p-GSK-3βSer9 and Snail were also detected by Western blot. RESULTS: The A549/DDP cells in TGF-β1 (+) group were dispersive, showed a spindle-like shape and developed pseudopodia. This transformation was conformed to classic EMT markers. Compared with TGF-β1 (-) group, the protein expression of E-cadherin in TGF-β1 (+) group was significantly decreased (P<0.05), and N-cadherin was significantly increased (P<0.05). The protein levels of p-Akt, p-GSK-3βSer9 and Snail were also significantly increased (P<0.05). Compared with TGF-β1 (+) group, the protein levels of p-Akt, p-GSK-3βSer9 and Snail were significantly decreased in LY294002 group (P<0.05). No difference of Akt and GSK-3β expression between TGF-β1 (-) group and TGF-β1 (+) group was observed. CONCLUSION: The mechanism of EMT in A549/DDP cells might be related to Akt/GSK-3β/Snail signaling pathway activated by TGF-β1.  相似文献   

11.
AIM: To explore the effect of microRNA-221 (miR-221) on the proliferation of lung cancer A549 cells, and to investigate its mechanism. METHODS: The A549 cells were transfected with miR-221 mimics by Lipofectamine 2000. The expression of miR-221 was detected by RT-qPCR. The expression of PTEN at mRNA and protein le-vels was detected by RT-qPCR and Western blot, respectively. The cell proliferation was examined by CCK-8 assay and colony formation assay. The 3'-UTR of PTEN was cloned into luciferase reporter vector and its enzymatic activity was detected to verify whether miR-221 targeted to PTEN. RESULTS: The expression level of miR-221 in the A549 cells was significantly increased after transfection with miR-221 mimics as compared with negative control group and blank group (P<0.01). The mRNA and protein levels of PTEN were significantly down-regulated compared with control group and blank group (P<0.05). In addition, miR-221 over-expression significantly promoted the proliferation of A549 cells (P<0.05). Moreover, miR-221 inhibited the enzymatic activity of luciferase reporter vector of PTEN. CONCLUSION: Over-expression of miR-221 significantly promotes the proliferation ability of human lung cancer A549 cells by down-regulation of PTEN.  相似文献   

12.
AIM:To explore the effect of microRNA-125a-5p (miR-125a-5p) on cisplatin (DDP) resistance of non-small-cell lung cancer A549/DDP cells and its related mechanisms. METHODS:The expression levels of miR-125a-5p and LIM kinase 1 (LIMK1) in non-small-cell lung cancer tissues, A549 cells and A549/DDP cells were detected by RT-qPCR. The A549/DDP cell viability, apoptotic rate and expression of drug resistance-related proteins after over-expression or knockdown of miR-125a-5p and/or LIMK1 expression were detected by MTT assay, flow cytometry and Western blot, respectively. The targeting relationship between miR-125a-5p and LIMK1 was verified by TargetScan online prediction and dual-luciferase reporter system. The cell viability, apoptotic rate and expression of drug resistance-related proteins after co-expression of miR-125a-5p and LIMK1 were also determined. RESULTS:The expression level of miR-125a-5p was down-regulated and LIMK1 expression was up-regulated in non-small-cell lung cancer tissues and cell lines (P<0.05). The results of dual-luciferase assay indicated that miR-125a-5p negatively regulated the expression of LIMK1. The expression of drug resistance-related proteins and the viability of A549/DDP cells were inhibited after over-expression of miR-125a-5p or knockdown of LIMK1, while the apoptosis was enhanced. Over-expression of LIMK1 attenuated the inhibitory effect of miR-125a-5p on A549/DDP cell viability and drug resistance-related protein expression (P<0.05). CONCLUSION:miR-125a-5p reverses the resistance of A549/DDP cells to DDP by inhibiting the expression of LIMK1 and drug resistance-related proteins.  相似文献   

13.
AIM:To study the effects of microRNA-105(miR-105) on the cell proliferation, migration and invasion abilities of non-small-cell lung cancer (NSCLC) H460 cells, and further to explore its mechanism. METHODS:The expression of miR-105 and kinesin family member C1 (KIFC1) mRNA in the NSCLC tissues and adjacent tissues and cells was detected by RT-qPCR. The protein expression of KIFC1 in the NSCLC tissues, adjacent normal tissues and cells was determined by Western blot. The H460 cells were divided into miR-105 group (transfection with miR-105 mimics), miR-negative control (NC) group (transfection with miR-NC), inhibitor-NC group (transfection with NC of inhibitor), inhibitor-miR-105 group (transfection with miR-105 inhibitor), si-NC group (transfection with NC siRNA), si-KIFC1 group (transfection with KIFC1 siRNA), miR-105+vector group (miR-105 mimics and pcDNA 3.1 co-transfection) and miR-105+KIFC1 group (miR-105 mimics and pcDNA 3.1-KIFC1 co-transfection). The cell proliferation was measured by MTT assay and colony formation assay. The migration and invasion abilities were detected by Transwell methods. The relative luciferase acitivity was evaluated by double luciferase reporter assay. RESULTS:Compared with the adjacent tissues, the expression of miR-105 was significantly decreased and the expression of KIFC1 was significantly increased in NSCLC tissues (P<0.05). Compared with human normal embryonic lung fibroblasts MRC-5, the expression of miR-105 in the H460 cells was significantly decreased, and the expression of KIFC1 was significantly increased (P<0.05). miR-105 inhibited the relative luciferase activity of H460 cells with wild-type KIFC1 and negatively regulated the protein expression of KIFC1. Over-expression of miR-105 and knockdown of KIFC1 expression significantly inhibited the proliferation, migration and invasion abilities of H460 cells. Over-expression of KIFC1 reversed the inhibitory effect of miR-105 on the cell proliferation, migration and invasion abilities of H460 cells. CONCLUSION:miR-105 inhibits the proliferation, migration and invasion abilities of NSCLC cells. The mechanism may be related to targeting and negatively regulating expression of KIFC1.  相似文献   

14.
AIM:To investigate the molecule mechanism of microRNA (miR)-30c over-expression inhibiting malignant phenotypes of cervical cancer cells. METHODS:Cervical cancer cell lines C33A, HeLa, SiHa and CaSki were transfected with pGenesil-1-miR-30c plasmid using Lipofectamine 2000 kit, and the expression of miR-30c was determined by TaqMan real-time PCR. The cell viability inhibition rate, colony formation ability, migration rate and apoptotic rate were measured by MTT assay, colony formation assay, Transwell experiment, and flow cytometry with Annexin V-FITC staining. The protein expression of Bax, Bcl-2, matrix metalloproteinase (MMP)-9, MMP-13 and tissue inhibitor of metalloprotei-nase-1 (TIMP-1) was detected by Western blot. RESULTS:The expression levels of miRNA-30c in the cervical cancer cell lines transfected with pGenesil-1-miR-30c plasmid were significantly higher than those in negative control groups (cell lines transfected with pGenesil-1 plasmid) (P<0.01). Significantly increased cell viability inhibition rate, and decreased colony formation ability and migration rate were found in the cervical cancer cell lines over-expressing miR-30c as compared with negative control groups (P<0.05). The apoptotic rate in the cervical cancer cell lines over-expressing miR-30c was dramatically higher than that in control groups (P<0.05). Over-expression of miR-30c in cervical cancer cells promoted the protein expression of Bax and TIMP-1, and decreased the protein expression of Bcl-2 and MMP-13 (P<0.05 or P<0.01). CONCLUSION:Over-expression of miR-30c significantly inhibits the viability and migration, and induces apoptosis of cervical cancer cells. The mechanism may be related to activating apoptosis pathway and inhibiting MMP-13 protein expression.  相似文献   

15.
AIM: To investigate whether the PI3K/Akt signaling pathway regulates the expression of ABC transporter through the downstream glycogen synthase kinase-3β (GSK-3β) pathway and participates in the multidurg resistance of colorectal cancer (CRC) HCT-15 cells. METHODS: Colorectal cancer HCT-15 cells were cultured and then treated with GSK-3β inhibitor (HY-19807) and PI3K/Akt pathway inhibitor (HY-13898), respectively. The median inhibitory concentration (IC50) of oxaliplatin for HCT-15 cells in each group was detected by CCK-8 assay, the inhibition rate and resistance index were also calculated. The protein levels of Akt, p-Akt, GSK-3β, p-GSK3β-Ser9 and ABC transporters P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (MRP-2) in the HCT-15 cells were determined by Western blot. The mRNA expression of ABC transporter in the HCT-15 cells was detected by RT-qPCR. The cell cycle distributions were analyzed by flow cytometry assasy. RESULTS: After GSK-3β inhibitor HY-19807 was used in the HCT-15 cells, the median inhibitory concentration of oxaliplatin was significantly increased, the protein levels of p-GSK3β-Ser9, P-gp and MRP-2 were up-regulated compared with control group (P<0.05), the changes of Akt and p-Akt were not obvious compared with control group (P>0.05). The results of RT-qPCR also showed that the mRNA levels of ABCB1 and ABCC2 were increased (P<0.01). Meanwhile, analysis of the cell cycle distribution showed that GSK-3β inhibitor HY-19807 promoted HCT-15 cell transition from G1 phase to S phase, and cell proliferation was vigorous. After the PI3K/Akt pathway inhibitor HY-13898 was applied to HCT-15 cells, the IC50 of oxaliplatin was decreased compared with control group (P<0.05). Moreover, the protein levels of p-Akt, p-GSK3β-Ser9, P-gp and MRP-2 were down-regulated (P<0.01). RT-qPCR results also showed that the mRNA expression of ABCB1 and ABCC2 was decreased (P<0.01). At the same time, G1 phase was prolonged, which inhibited cell transition from G1 phase to S phase, and inhibited cell proliferation. The protein expression of total GSK-3β was consistent in each group. CONCLUSION: The PI3K/Akt signaling pathway is involved in the proliferation and multidrug resistance of colorectal cancer HCT-15 cells by regulating the phosphorylation of GSK-3β and changing the expression of ABC transporter.  相似文献   

16.
AIM: To investigate the effect of microRNA(miR)-193b on doxorubicin therapy in breast cancer in vitro.METHODS: miR-193b level in plasma was detected by real-time PCR in the patients with breast cancer or the healthy controls. MTT assay was performed to measure the inhibitory effect of miR-193b plus doxorubicin on the growth of MDA-MB-231 cells. Bioinformatics, real-time PCR and Western blot were performed to determine whether the expression of Mcl-1 was regulated by miR-193b. Mcl-1 expression vector was constructed, and the role of Mcl-1 vector toward miR-193b plus doxorubicin-induced cytotoxicity in MDA-MB-231 cells was observed by MTT assay.RESULTS: Down-regulation of miR-193b was found in breast cancer patients. The miR-193b plus doxorubicin group showed a higher growth inhibition than cisplation group in MDA-MB-231 cells. The expression of Mcl-1 at both mRNA and protein levels was down-regulated after miR-193b transfection. The growth inhibition of MDA-MB-231 cells treated with miR-193b plus doxorubicin was significantly decreased after the transfection of Mcl-1 expression vector.CONCLUSION: miR-193b sensitizes doxorubicin-induced cytotoxicity by targeting Mcl-1 in breast cancer.  相似文献   

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18.
AIM: To observe the changes of Notch1 expression and autophagy in the renal tissues of diabetic mice, and to explore the regulatory effect of Notch1 on tubulointerstitial fibrosis by inhibiting autophagy in diabetic nephro-pathy. METHODS: The mice were randomly divided into normal control group (db/m mice) and diabetes group (db/db mice), with 8 rats in each group. After 12 weeks of feeding, the mice were sacrificed and the corresponding biochemical indexes were measured. The protein expression of Notch1 in the renal tubular epithelial cells was observed by immunohistochemical staining. The protein levels of Notch1, PTEN, p-Akt (Thr308), Akt, p-mTOR (Ser2448), mTOR, LC3, P62, collagen type Ⅰ (Col-Ⅰ) and collagen type Ⅲ (Col-Ⅲ) were determined by Western blot. RESULTS: Compared with the db/m mice, the blood glucose, glycosylated hemoglobin, serum creatinine, triglyceride and total cholesterol were increased in the db/db mice (P<0.01). Renal tubular epithelial cell vacuolar degeneration, renal tubular expansion and interstitial inflammatory cell infiltration in db/db mouse renal tissues with HE staining were observed. The images of Masson staining showed collagenous fiber-like substance deposition in the glomerular capillaries and renal interstitium, and disarrangement of tubular structure in the renal tissues of db/db mice. The protein expression levels of PTEN and LC3-Ⅱ were decreased (P<0.01 or P<0.05), while the protein levels of Notch1, P62, p-mTOR (Ser2448), p-Akt (Thr308), Col-I and Col-III were increased in the db/db mice as compared with the db/m mice (P<0.01). However, no significant change of total mTOR and Akt proteins between the 2 groups was found. CONCLUSION: Notch1 protein expression was increased, PTEN expression was significantly reduced, Akt/mTOR pathway was activated, autophagy was inhibited, and fibrosis was aggravated in the renal tissues of the diabetic mice.  相似文献   

19.
AIM: To investigate the effect of down-regulation of X-box binding protein 1 (XBP1) expression on the viability and apoptosis of glioma cells. METHODS: The mRNA expression of XBP1 in the glioma tissues was detected by qPCR. Small interfering RNA (siRNA) interfering with XBP1 expression (XBP1-siRNA) was transfected into human brain glioma U251 cells. At the same time, control group (the cells without special treatment) and negative control (NC-siRNA) group (transfected with siRNA without any interference) were set up. The mRNA expression of XBP1 in the 3 groups 48 h after transfection was detected by qPCR. The protein levels of XBP1, proliferating cell nuclear antigen (PCNA), B-cell lymphoma/leukemia-2 (Bcl-2), Bcl-2-associated X protein (Bax), cyclin D1 (cyclin D1), phosphatidylinositol 3-kinase (PI3K) and phosphorylated Akt (p-Akt) were determined by Western blot. The cell viability was measured by CCK-8 assay. The cell cycle distribution and apoptosis were analyzed by flow cytometry. RESULTS: The expression level of XBP1 in the glioma tissues was significantly higher than that in the tumor adjacent tissues (P<0.05). The XBP1 expression at mRNA and protein levels was significantly decreased in the cells transfected with XBP1-siRNA (P<0.05). No statistically significant difference of the cell viability, cell cycle, apoptotic rate and the protein levels of PCNA, Bcl-2, Bax, cyclin D1, PI3K and p-Akt between NC-siRNA group and control group was observed. Compared with control group, the cell viability, S-phase cells and the protein levels of PCNA, Bcl-2, cyclin D1, PI3K, and p-Akt in XBP1-siRNA group were decreased significantly, and the apoptotic rate, G0/G1-phase cells and Bax protein expression were significantly increased (P<0.05). CONCLUSION: Down-regulation of XBP1 gene expression in brain glioma cells reduces the viability of cancer cells, blocks the cells in G1 phase and promote apoptosis. The mechanism is related to the inhibition of PI3K/Akt signaling pathway.  相似文献   

20.
AIM: To investigate the effect of microRNA-486 (miR-486) on lipopolysaccharide (LPS)-induced apoptosis of alveolar epithelial cell A549. METHODS: A549 cells were treated with LPS, and the expression of miR-486 was detected by RT-qPCR. miR-486 mimics were transfected into LPS-induced A549 cells, and RT-qPCR was used to detect the up-regulation effect. The apoptotic rate was analyzed by flow cytometry and the protein levels of cleaved caspase-3 (C-caspase-3) and C-caspase-9 were determined by Western blot. The target gene prediction software was used to predict the target gene PTEN of miR-486. Luciferase reporter vector was used to identify the target relationship. pcDNA 3.1-PTEN and miR-486 mimics were co-transfected into A549 cells to detect the effect of PTEN up-regulation on apoptosis of miR-486 mimics transfected A549 cells stimulated with LPS. RESULTS: After LPS treatment, the expression of miR-486 in A549 cells was significantly decreased (P<0.05). Transfection of miR-486 mimics significantly up-regulated the expression of miR-486 in A549 cells stimulated with LPS (P<0.05). The apoptotic rate of A549 cells and the protein levels of C-caspase-3 and C-caspase-9 were significantly increased after LPS treatment (P<0.05). Up-regulation of miR-486 significantly down-regulated LPS-induced apoptosis of A549 cells (P<0.05). The expression of PTEN was negatively regulated by miR-486. Transfection of pcDNA 3.1-PTEN significantly increased the expression of PTEN, promoted the apoptosis and increased the protein levels of C-caspase-3 and C-caspase-9 in A549 cells stimulated with LPS after co-transfection with miR-486 mimics(P<0.05). CONCLUSION: miR-486 inhibits PTEN expression and reduces LPS-induced apoptosis of A549 cells.  相似文献   

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