Activation of caspase-3 during bacterial redox protein azurin -induced apoptosis in U2OS cells

AIM: To study whether caspase-3,8 is activated during azurin-induced apoptosis in U2OS cells. METHODS: AnnexinV /PI method was used to detect apoptosis. The changes of procaspase-3 were analyzed by Western blot, the changes of caspase-3 mRNA were detected by semi-quantitative RT-PCR, and caspase-3 relative activity was determined by colorimetric assay. RESULTS: After U2OS cells were treated with 0, 25, 50, 100, 200, 500 mg/L azurin for 24 h, respectively, the level of procaspase-3 protein decreased and the level of caspase-3 mRNA increased as azurin concentration increased. When the cells were treated with 100 mg/L azurin for 6, 12, 24, 48 h, respectively, the caspase-3 activity began to rise from 6 h,reached the peak at 24 h,and was still higher than the control group at 48 h (P<0.01). After the cells were treated with azurin at different concentrations for 24 h, caspase-3 activity increased in a concentration -dependent manner. CONCLUSION: Caspase-3 is activated and plays an important role in azurin-induced apoptosis in U2OS cells.     

Nisin induces apoptosis of human osteosarcoma MG63 cells via oxidative stress

AIM To investigate the effect of nisin on apoptosis of human osteosarcoma MG63 cells and its related oxidative stress mechanism. METHODS The MG63 cells were cultured in the medium containing different concentrations of nisin with or without antioxidant N-acetyl-L-cysteine （NAC）. The cell viability was measured by CCK-8 assay. Apoptosis was analyzed by flow cytometry with annexin-V/PI staining. The production of intracellular reactive oxygen species （ROS） was detected by redox-sensitive dye 2',7'-dichlorofluorescein diacetate （DCFH-DA）. The 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl benzimidazolyl carbocyanine iodide （JC-1） was used to detect the changes of mitochondrial membrane potential （MMP）. The protein levels of apoptosis-associated molecules Bax, Bcl-2 and cleaved caspase-3 were determined by Western blot. RESULTS Nisin decreased the viability of MG63 cells and promoted the apoptosis in a dose-dependent manner. It also up-regulated the protein level of cleaved caspase-3, increased the protein expression ratio of Bax/Bcl-2, triggered a large amount of intracellular ROS generation and reduced the MMP （P<0.05）. Moreover, antioxidant NAC significantly inhibited nisin-induced apoptosis of MG63 cells, down-regulated the protein level of cleaved caspase-3, decreased Bax/Bcl-2 ratio, reduced intracellular ROS level, and restored the MMP （P<0.05）. CONCLUSION Nisin may promote oxidative stress in human osteosarcoma cells, activate mitochondrial apoptosis pathway, and eventually induce apoptosis.     

Relation of Fas/FasL-mediated caspase-3 activation with acinar cell apoptosis in rats with acute pancreatitis

AIM: To observe the expression and interrelationship of apoptosis controlling genes and proteins Fas, FasL, caspase-3 in rats with acute pancreatitis (AP). METHODS: Forty male Sprague Dawley rats were randomly divided into four groups, 10 rats each group. Acute pancreatitis with different inflammatory degree was induced by retroinjecting 2.0%, 3.5% or 5.0% sodium taurocholate at dose of 1 mL/kg body weight into the pancreaticobiliary duct. All the rats were sacrificed 6 h after operation. The pathologic changes of pancreas were observed under optical microscope. The protein and mRNA expressions of Fas, FasL, caspase-3 in pancreatic tissue were measured by Western blotting and RT-PCR. The apoptosis of acinar cells was measured by the methods of in situ end labeling. RESULTS: In normal pancreatic tissue, there appeared the protein and mRNA expression of Fas, FasL, caspase-3. In acute pancreatitis with different inflammatory degree, with the degree of inflammation worsen, the apoptosis cells tapered, the expression of above protein and mRNA also descended gradually. Furthermore, the variation tendency of caspase-3 among the four groups was in coincidence with Fas or FasL. CONCLUSION: Fas/FasL -mediated apoptotic pathway participates in the regulation of acinar cell apoptosis in acute pancreatitis.     

Nodosin induces apoptosis of HepG2 cells by increasing Apaf-1 expression and activating caspase-3

AIM:To investigate the effects of nodosin on apoptosis of human hepatocellular carcinoma HepG2 cells. METHODS:HepG2 cells were treated with nodosin at different concentrations (1.25 μmol/L, 2.5 μmol/L, 5 μmol/L, 10 μmol/L and 20 μmol/L) for 24 h. The morphological changes of the HepG2 cells were observed by Hoechst 33258 staining and electron microscopy. The apoptotic rates were analyzed by flow cytometry. The mRNA expression of apoptotic protease-activating factor-1 (Apaf-1) was detected by RT-qPCR. The protein levels of pro-caspase-3, caspase-3 and cleaved caspase-3 were determined by Western blot. RESULTS:HepG2 cells showed obvious cell shrinkage and nucleus drift when treated with nodosin as the concentration was increased. Many apoptotic bodies were observed in 5 μmol/L, 10 μmol/L and 20 μmol/L nodosin groups. The mRNA expression of Apaf-1 was increased in 5 μmol/L, 10 μmol/L and 20 μmol/L nodosin groups as compared with control group (P<0.05). The protein levels of pro-caspase-3, caspase-3 and cleaved caspase-3 were increased with the increasing dose of nodosin (P<0.05). CONCLUSION:Nodosin induces the apoptosis of HepG2 cells. This effect was related to increasing Apaf-1 mRNA expression and subsequently promoting the activation of caspase-3.     

Effect of Ginsenoside Rh2 on apoptosis of human osteosarcoma cell line MG-63

AIM: To investigate the effect of Ginsenoside Rh2(Rh2) on the apoptosis of human osteosarcoma cell line MG-63.METHODS: The cell viability was determined by MTT assay. MG-63 cell apoptotic rate was examined by flow cytometry with Annexin V-PI double staining. The expression of Bcl-2, Bax, cytochrome C(Cyt C) and cleaved caspase-3 were measured by Western blot.RESULTS: Rh2 enhanced the apoptosis of MG-63 cells in a dose-dependent manner. Furthermore, after treatment with Rh2, the release of mitochondrial Cyt C and Bax expression were increased, while Bcl-2 and the ratio of Bcl-2/Bax were decreased as compared with control group(P<0.05). The protein level of cleaved caspase-3 was also increased(P<0.05).CONCLUSION: Ginsenoside Rh2 accelerates the apoptosis of MG-63 cells through mitochondria-dependent pathway, suggesting that Rh2 is a novel approach for the treatment of osteosarcoma.     

Knockdown of astrocyte elevated gene-1 by siRNA inhibits cell proliferation and induces apoptosis in human neuroblastoma cell line

AIM: To investigate the effect of siRNA-induced astrocyte elevated gene-1 ( AEG-1 ) down-regulation on the proliferation, apoptosis and cell cycle of neuroblastoma cells. METHODS: An siRNA targeting to AEG-1 mRNA (AEG-1 siRNA) was constructed and transfected into neuroblastoma cells with Lipofectamine 2000. A non-specific siRNA (control siRNA) and non-treatment were used as negative control and blank control,respectively . The cell proliferation was detected by MTT method and colony formation assay. The apoptosis and cell cycle were analyzed by flow cytometry. RESULTS: Compared with control groups, the expression of AEG-1 mRNA was evidently declined in the cells transfected with AEG-1 siRNAs (P<0.05). AEG-1 siRNA significantly decreased the cell proliferation. After treated with AEG-1 siRNA for 48 h, the percentage of apoptotic cells was significant increased and the cell cycle was arrested in G₀/G₁ phase compared with the control cells (P<0.05). CONCLUSION: The mRNA expression of AEG-1 is down-regulated by AEG-1 siRNA in neuroblastoma cells. Knockdown of AEG-1 expression in human neuroblastoma cells significantly inhibits cell proliferation and apoptosis, and induces cell arrest in G₀/G₁ phase of the cell cycle.     

Repressive effect of miRNA-363 via SOX4 on human osteosarcoma cell growth and apoptosis

AIM: To detect the expression of miRNA-363 and SOX4 in osteosarcoma tissues and to investigate the effect of miRNA-363 on the viability and apoptosis of human osteosarcoma cell line MG-63.METHODS: Real-time PCR was used to detect the expression level and the relationship of miRNA-363 and SOX4 mRNA in the osteosarcoma tissues and the corresponding paratumorous tissues collected from 63 patients. The expression levels of miRNA-363 and SOX4 in osteosarcoma cell line MG-63 after transfected with miRNA-363 mimics were measured. The cell viability was measured by CCK-8 assay. Flow cytometry was used to monitor the changes of cell cycle and apoptosis. The changes of SOX4 and miRNA-363 expression levels in the MG-63 cells after transfection with SOX4 siRNA or pcDNA/SOX4 was detect by real-time PCR.RESULTS: The expressed level of miRNA-363 was lower, and the expression level of SOX4 was higher in the osteosarcoma tissues than those in the adjacent normal tissues. A significantly negative correlation between the expression levels of miRNA-363 and SOX4 was observed. The expression of miRNA-363 in the MG-63 cells after transfection with miRNA-363 mimics was significantly up-regulated, while the expression of SOX4 in the MG-63 cells was significantly down-regulated, with significant difference as compared with the cells transfected with miRNA-NC and control cells. The viability of MG-63 cells was inhibited, the cell cycle was arrested in G₀/G₁ phase, and the cell apoptosis was increased by transfection with miRNA-363 mimics. The relative protein expression levels of SOX4 in SOX4 siRNA group and pcNDA/SOX4 group were significantly different from those in negative control group, but the relative expression levels of miRNA-363 had no significant difference. Over-expression of SOX4 restored the viability of the MG-63 cells reduced by miR-363.CONCLUSION: The expression level of miRNA-363 is low in human osteosarcoma tissue. miRNA-363 may inhibits the viability of osteosarcoma cell line MG-63 and promotes cell apoptosis in vitro via inhibiting the SOX4 expression.     

Induction of apoptosis by c-myc antisense oligonucleotide in osteosarcoma cell MG-63

AIM: To study the induction of apoptosis by c-myc antisense oligonucleotide in osteosarcoma cell (MG-63).METHODS: The designed c-myc antisense oligonucleotide fragment was transfected into human osteosarcoma MG-63 cells. The cell growth and apoptosis were measured by the methods of MTT, FCM, HE staining and transmission electron microscopy.RESULTS: The results showed that the proliferation of human osteosarcoma MG-63 cells was inhibited and apoptotic rate was 37.92% when treated with c-myc antisense oligonucleotide at the does of 10.0 μmol/L for 48 h. c-myc antisense oligonucleotide (10.0 μmol/L) also inhibited the expression of c-myc protein.CONCLUSION: c-myc antisense oligonucleotide is able to induce apoptosis in human osteosarcoma MG-63 cells.     

Knockdown of RALA by siRNA inhibits cell proliferation and induces apoptosis in human leukemic K562 cells

AIM: To investigate the effect of siRNA-induced knockdown of v-ral simian leukemia viral oncogene homolog A(RALA) on proliferation and apoptosis of chronic myelogenous leukemia(CML) K562 cells. METHODS: The chemically synthesized siRNA targeting to RALA gene was transfected into K562 cells using Lipofectamine^TM 2000. The proliferation and viability of K562 cells were detected by MTT assay and trypan blue dye exclusion. The expression levels of RALA mRNA and protein were determined by quantitative real-time PCR and Western blotting,respectively. The cell apoptosis was analyzed using flow cytometry by double staining with annexin V and propidium iodide, and the apoptotic morphological changes were detected by Hoechst 33258 staining. RESULTS: RALA siRNA significantly down-regulated RALA mRNA and protein expression in K562 cells(P<0.05). The proliferation of K562 cells in RALA siRNA group was inhibited compared with control group(P<0.05). The apoptotic rate was much higher in RALA siRNA group than that in negative control group(P<0.05). The apoptotic morphological changes were observed in the nuclei of K562 cells transfected with RALA siRNA. CONCLUSION: The siRNA-mediated knockdown of RALA results in inhibition of proliferation and induction of apoptosis in K562 cells, indicating that RALA might be used as a potential therapeutic target in chronic myelogenous leukemia.     

RNA interfering retinoblastoma-like protein 2 gene induces apoptosis of human cardiac stem cells mediated by DNA methyltransferase

AIM: Retinoblastoma-like protein 2 (Rbl-2) plays an important role in the cell proliferation and DNA methyltransferase (DNMT) may involve in the regulation of differentiation in embryonic stem cells. This study is to investigate the effect of knocking down Rbl-2 by specific siRNA on apoptosis in human cardiac stem cells.METHODS: The siRNA of Rbl-2 (siRbl-2) was transfected into human cardiac stem cells. The mRNA expression of Rbl-2 and DNMT-3B was detected by real-time RT-PCR 48 h after transfection. The DNMT-3B protein expression and the activation of caspase-3 were determined by Western-blotting. The cell apoptosis was analyzed by flow cytometry with annexin V-FITC/PI staining. RESULTS: Knocking down of Rbl-2 gene increased the expression of DNMT-3B in human cardiac stem cells, and induced cell apoptosis. Compared with negative control group, caspase-3 was activated and cleaved caspase-3 was increased in the stem cells transfected with siRbl-2. The cleaved caspase-3 accounted for more proportions of total caspase-3 in transfected cells than that in non-transfected cells (P<0.01). The apoptotic rate was also increased significantly in transfected group (P<0.01).CONCLUSION: Rbl-2 plays an important role in the regulation of survival and apoptosis in human cardiac stem cells. This regulatory mechanism may involve in epigenetic modification, which is mediated by DNMT.     

Resveratrol enhances 5-fluorouracil-induced apoptosis of osteosarcoma CD133+ cell subset by promoting formation of Apaf-1/caspase-9 complex

AIM:To investigate the synergistic effect of resveratrol and 5-fluorouracil on osteosarcoma CD133⁺ cell subset.METHODS:Human osteosarcoma cell line MG-63 CD133⁺ cell subset and the corresponding CD133^- cell subset were treated with resveratrol and 5-fluorouracil.After treatment,the viability of MG-63 cells was measured by MTT assay.The apoptosis of MG-63 cells was analyzed by flow cytometry.Activation of caspase-9 and caspase-3,the expression of Apaf-1,and the release of cytochrome C were evaluated by Western blot.The interaction between Apaf-1 and pro-caspase-9 was detected by co-immunoprecipitation.RESULTS:The cell death and apoptosis of MG-63 CD133⁺ cell subset induced by 5-fluorouracil were significantly weaker than those in the corresponding MG-63 CD133^- cell subset.However,co-treatment with resveratrol significantly enhanced the effect of 5-fluorouracil on inhibiting the viability of MG-63 CD133⁺ cell subset.Mechanically,treatment with resveratrol upregulated the expression of Apaf-1.Transfection with Apaf-1 siRNA abolished the synergistic effect of resveratrol and 5-fluorouracil in MG-63 CD133⁺ cell subset.In addition,the results of co-immunoprecipitation indicated that the combination of resveratrol and 5-fluorouracil significantly induced the formation of Apaf-1/pro-caspase-9 complex,leading to the activation of caspase-9 in MG-63 CD133⁺ cell subset.CONCLUSION:Resveratrol enhances 5-fluorouracil-induced apoptosis of osteosarcoma CD133⁺ cell subset by promoting the formation of Apaf-1/caspase-9 complex.     

Dithiothreitol induces apoptosis of BRL-3A cells by activation of calpain-2/caspase-12 signaling pathway

AIM: To investigate the expression changes of glucose-regulated protein 78 (GRP78), calpain-2, caspase-12 and caspase-3 in dithiothreitol (DTT)-induced endoplasmic reticulum stress in rat normal liver cell line BRL-3A, and to explore their effects on apoptosis of BRL-3A cells. METHODS: BRL-3A cells were treated with 2.5 mmol/L DTT to induce endoplasmic reticulum stress. The mRNA expression of GRP78, calpain-2, caspase-12 and caspase-3 was detected by real-time PCR. The protein expression of GRP78, calpain-2, caspase-12 and caspase-3 was detected by cell immunofluorescence technique. The protein levels of cleaved caspase-12 and cleaved caspase-3 were determined by Western blot. The apoptosis of BRL-3A cells was analyzed by flow cytometry. RESULTS: After treatment with DTT for 12 h and 24 h, the mRNA expression of GRP78, calpain-2 and caspase-12 in the BRL-3A cells was obviously increased compared with normal control group (P<0.01), and no significant change of caspase-3 mRNA after treatment with DTT for 12 h and 24 h was observed. The results of immunofluorescence technique and Western blot showed that the protein levels of GRP78, calpain-2, caspase-12, cleaved caspase-12, caspase-3 and cleaved caspase-3 were obviously elevated after treatment with DTT for 12 h and 24 h(P<0.05). In addition, the increased apoptotic rate was also found in the BRL-3A cells treated with DTT for 12 h and 24 h (P<0.05). CONCLUSION: The activation of calpain-2/caspase-12 signaling pathway may be involved in apoptosis of BRL-3A cells induced by DTT.     

IL-12 induces T lymphocytes apoptosis and influences the expression and signal transduction of Fas/FasL

AIM: IL-12 acts upon Tlymphocytes and activates its receptor complexes of β1/β2,and so IL-12 can regulate TH1/TH2 balance. Our study is aimed at IL-12-inducing apoptosis of Tcells and expression and signal transduction of Fas/FasLduring Tcell apoptosis. METHODS: The apoptosis of Tcells was detected by Annexin Vstaining cytometry and the expression of Fas/FasLunder different inhibitors were detected by semi-quantitative PCR. RESULTS: IL-12 induced the human leukemic Tcell line(TIB-152) and the human lymphoma Tcell line(HTB-176) and the normal human Tcells to undergo apoptosis. The FasLexpression at 6 hours after treatment with IL-12 increased apparently, and reached the max at 24 hours, and FasLexpression induced by IL-12 was inhibited by PKCinhibitor. But IL-12 did not influence Fas expression. CONCLUSIONS: IL-12 can induce Tcells to undergo apoptosis which is characterized by early membrane changes, the inducing effect is correlated with the concentration of IL-12 and the maturation of Tcells. FasLparticipates in the progression of Tcell apoptosis as a apoptosis mediator, and the effect of IL-12 on FasLexpression may be related with PKCpathway.     

Thapsigargin inhibits growth and induces apoptosis in human len epithelial cell line HLE-B3 in vitro

AIM: To study the effect of growth inhibition and its mechanism of thapsigargin (TG) on HLE-B3 cell line in vitro. METHODS: MTT assay was performed to detect the growth inhibition effect of TG on HLE-B3 cell line. Flow cytometry and DNA fragmentation were used to examine cell apoptosis. Western blotting analysis was used to determine the relative protein expression. Furthermore, the concentration of cytoplasm Ca2+ was assessed by fluorescence colorimetric assay. RESULTS: Different concentrations of TG significantly inhibited growth of HLE-B3 cells, and inhibitory concentrations of 50 percent at 12 h, 24 h and 48 h were (2.27±0.61) μmol/L, (0.77±0.12) μmol/L and (0.15±0.04) μmol/L, respectively. Moreover, TG induced cell apoptosis, decreased SERCA2 protein expression, and increased greatly the concentration of cytoplasm Ca2+, Bax and caspase 3 protein levels.CONCLUSION: TG inhibits growth and induces apoptosis in HLE-B3 cells in vitro. The mechanism may be through endoplasmic reticulum pathway. These observations may provide a novel strategy for the treatment of posterior capsular opacification.     

Effects of Fas,NF-κB and caspases on microvascular endothelial cell apoptosis induced by TNFα

AIM:To study the apoptotic effect of TNFα on rat pulmonary microvascular endothelial cells(PMVEC)and the role of Fas, NF-κB in its mechanism. METHODS: Apoptosis of PMVEC was analyzed and quantitated with TUNEL, flow cytometer. Northern blot was applied to assess the influence of TNFα on PMVEC Fas expression. Fas antibody was used to investigate the apoptotic effect of Fas on PMVEC. Activation of caspase-8 was examined by Western blot. Expression of caspase-3 was analyzed with histo-immunochemical staining. RESULTS:Growth curve showed that TNFα suppressed endothelial cell proliferation in a dose-dependent manner. After treatment with 5×10⁶U/LTNFα, apoptotic rate was 14.0%±3.1% detected with TUNEL, and 13.1% with flow cytometer. When the cells were co-cultured with TNFα and APDC, an NF-κB inhibitor, less cells were viable and more cells were positively stained with TUNEL. Fas expression in PMVEC was elevated after TNFα treatment. Co-culturing with Anti-Fas antibody aggravated PMVEC apoptosis. Caspase-8 activity and caspase-3 expression was elevated. Caspase-3 inhibitor significantly ameliorated PMVEC apoptosis. CONCLUSION: Large dose of TNFα(5×10⁶U/L) can induce apoptosis in rat PMVEC. NF-κB has an anti-apoptotic effect in PMVEC. TNFα up-regulates Fas expression in PMVEC, and the latter takes a part in apoptosis. Caspase-8 and caspase-3 are involved in PMVEC apoptosis induced by TNFα.     

Changes and significance of Fas and cFLIP in apoptosis of human rhabdomyosarcoma cells induced by combination of TRAIL and cisplatin

AIM: To investigate the synergistic induction of apoptosis in rhabdomyosarcoma cells by the combination of TRAIL or TRAIL gene with cisplatin. METHODS: Rhabdomyosarcoma cells were treated with TRAIL, Ad／GT-TRAIL, cisplatin, respectively or the combination for 3 days. The cytotoxicity was observed by MTT assay. The apoptotic rates and the expression rates of Fas protein were measured by flow cytometry (FCM). The expression of cFLIP mRNA was determined by RT-PCR. RESULTS: Rhabdomyosarcoma cells were treated with Ad／ GT-TRAIL and TRAIL (100.0 μg/L), the cytotoxicity index were 52.5% and 43.5%, the percentage of apoptotic cells were 12.95% and 10.26%, respectively. Combined with cisplatin, the cytotoxicity index and the percentage of apoptotic cells were increased significantly (P<0.05). The expression of Fas protein in rhabdomyosarcoma cells was up-regulated and the expression of cFLIP was down-regulated with cisplatin, which were paralleled by the apoptotic rates. CONCLUSION: Combinatiion of Ad／GT-TRAIL or TRAIL and cisplatin has synergistic apoptosis-inducing effects on rhabdomyosacoma cells.     

NOD8 inhibits autophagy in human pancreatic cancer cells and effect of apoptosis on autophagy regulatd by NOD8

AIM: To explore whether NOD8 inhibits autophagy in human pancreatic cancer cells and its underlying mechanisms, and to investigate the effect of apoptosis on the autophagy regulated by NOD8. METHODS: The empty plasmid pEGFP-C2 and recombinant plasmid pEGFP-NOD8 were transfected into the Panc-1 cells using JetPRIME reagent.The untransfected cells served as control group. The protein levels of NOD8, autophagy-related proteins beclin-1 and LC3-II, and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway-related proteins Akt, p-Akt, mTOR and p-mTOR were determined by Western blot 48 h after transfection. Meanwhile, the number of LC3 spots was quantified by immunofluorescence staining. Furthermore, after a broad caspase inhibitor Z-VAD-FMK was applied to NOD8-over-expressing cells, the protein expression levels of beclin-1 and LC3-II were detected by Western blot and the number of LC3 spots was observed by immunofluorescence staining. RESULTS: The protein level of NOD8 in pEGFP-NOD8 group was significantly higher than that in control group and pEGFP-C2 group (P<0.01). The protein expression of beclin-1 and LC3-II, and the number of LC3 spots in pEGFP-NOD8 group were significantly decreased as compared with control group and pEGFP-C2 group. Moreover, the protein levels of p-AKT and p-mTOR in pEGFP-NOD8 group were higher than those in control group and pEGFP-C2 group, while no significant difference of mTOR and AKT protein expression was found among these 3 groups. Furthermore, the protein levels of beclin-1 and LC3-II, and the number of LC3 spots in pEGFP-NOD8+Z-VAD-FMK group were significantly increased compared with pEGFP-NOD8 group. CONCLUSION: NOD8 inhibits autophagy in the Panc-1 cells and its mechanism may be related to the activation of PI3K/Akt/mTOR pathways. Apoptosis enhances the inhibitory effect of NOD8 on autophagy.     

T0901317 induces apoptosis of human breast cancer MDA-MB-231 cells by up-regulating LXRα expression

AIM: To investigate the pro-apoptotic effect of T0901317, an artificial agonist of liver X receptor α (LXRα), on human breast cancer MDA-MB-231 cells and its mechanism. METHODS: MDA-MB-231 cells were treated with different concentrations (0, 10, 20 and 40 μmol/L) of T0901317 for different time (0, 12, 24 and 48 h). The cell apoptosis was determined by Annexin V/propidium iodide staining and Hoechst 33342 staining. The expression of apoptosis-related proteins, such as Bcl-2, caspase 3 and cleaved caspase-3, and LXRα was determined by Western blot. The mRNA expression of Bcl-2 and LXRα was analyzed by RT-qPCR. RESULTS: T0901317 induced the cell apoptosis in a dose-and time- dependent manner. The expression of cleaved caspase-3 and LXRα was up-regulated, but Bcl-2 was down-regulated by T0901317. The mRNA expression of Bcl-2 was down-regulated, while LXRα was up-regulated by T0901317.CONCLUSION: T0901317 up-regulates LXRα expression and induces the apoptosis of MDA-MB-231 cells.