Aim To evaluate the mechanism of HG251-induced apoptosis in K562/DOX cells.Methods Cell viability was assessed by MTT assay;cell cycle distribution,apoptosis and mitochondrial membrane potential were measured by flow cytometry;the protein expressions of P-gp,caspase-3,caspase-8,caspase-9,p53,Bcl-xL and cytochrome c in the K562/DOX cells were evaluated by Western blot.Results HG251 was able to inhibit cells proliferation,induce apoptosis,lose mitochondrial membrane potential,activate caspase-3,caspase-8,caspase-9,up-regulate p53 protein and down-regulate Bcl-xL protein in a dose-dependent manner but it had no effect on P-gp protein expression.Conclusion HG251 could overcome apoptotic resistance via up-regulating p53 protein and down-regulating Bcl-xL protein.In addition,HG251 also induced K562/DOX cells apoptosis via mitochondrial pathway and membrane death receptor pathway.

Objective:To elucidate action mechanism of δ-tocotrienol in inducing apoptosis of human hepatoma HepG2 cells. Methods:Cell proliferation and viability were assessed by MTT assay; cell cycle distribution, apoptotic rate and mitochondrial membrane potential were measured by using high content screening system; the expression of apoptosis-related protein such as caspase-3, caspase-8, caspase-9, Bcl-2, Bax, tBid and cytochrome C in the HepG2 cells were evaluated by Western blotting. Results:δ-Toco-trienol inhibited HepG2 cell proliferation and induced apoptosis in a dose-dependent manner. This growth-inhibiting effect of δ-toco-trienol correlated with loss of mitochondrial membrane potential and release of cytochrome C from mitochondria to cytoplasm, and regulation of the protein expression of Bcl-2 family members, such as up-regulation of Bax and tBid and down-regulation of Bcl-2. Subsequently tocotrienol induced the activation of caspase-3, caspase-8, and caspase-9 which finally induced apoptosis of hepatoma HepG2 cells. Conclusion:δ-Tocotrienol induced apoptosis of human hepatoma HepG2 cells via mitochondrial pathway and membrane death receptor pathway.

This paper is to report the study of resveratrol-induced apoptosis and its mechanisms in MCF-7 cells. MTT assay was performed to assess the cytotoxicity of resveratrol on MCF-7 cells. Hoechst 33258 staining was used to observe cellular morphologic changes in apoptosis. Apoptosis was measured by flow cytometric analysis and the protein expression was examined by Western blotting analysis. The results indicated that resveratrol could inhibit MCF-7 cell growth in a time- and concentration-dependent manner. Remarkable morphologic changes in the cells after 60 micromol L(-1) resveratrol treatment, including cell nuclear shrinkage, DNA condensation and apoptotic bodies, were observed by Hoechst 33258 staining. Resveratrol could induce apoptosis and activate p38 and p53 in a time dependent manner in MCF-7 cells. In addition, the cell growth inhibitory ratio and the apoptotic ratio of resveratrol-treated group decreased markedly by the p38 MAPK inhibitor SB203580 or p53 inhibitor pifithrin-alpha. Further experiments confirmed that resveratrol-induced p53 activation was reduced by SB203580 whereas the activation of p38 was not affected by pifithrin-alpha. In conclusion, resveratrol induced apoptosis in MCF-7 cells could be through activating p38-p53 signal pathway.

Treatment with the combination of Chinese herbs and cytotoxic chemotherapies showed a higher survival rate in clinical trials. In this report, the results demonstrated that the tanshinone II A, a key component of Salvia miltiorrhiza bunge, when it is combined with the cytotoxic drug cisplatin showed synergistic antitumor effects on human prostate cancer PC3 cells and LNCaP cells in vitro. Antiproliferative effects were detected with MTT assay. Cell cycle distribution and apoptosis were detected by flow cytometer. Protein expression was detected by Western blotting. The intracellular concentration of cisplatin was detected by high performance liquid chromatography. The results demonstrated that tanshinone II A significantly enhanced the antiproliferative effects of cisplatin on human prostate cancer PC3 cells and LNCaP cells with the increase of the intracellular concentration of cisplatin. These effects were correlated with cell cycle arrested at S phase and cell apoptosis. The apoptosis might be achieved through death receptor pathway and mitochondrial pathway. Furthermore, the Bcl-2 family members were also involved in this apoptotic process. Collectively, these results indicated that the combination of tanshinone II A and cisplatin had a better treatment effect in vitro not only on androgen-dependent LNCaP cells but also on androgen-independent PC3 cells.

This study is to investigate the antitumor activity of ophiopogonin B (OP-B). MTT assay, flow cytometric analysis, acridine orange staining, Lyso-Tracker Red staining and HeLa-GFP-LC3 transfect cells assay were used to detect the proliferation activity, apoptosis and autophagy of HeLa cells. The results showed that OP-B exerted potent antiproliferative activity on HeLa cells, the cell growth inhibition effect of OP-B was not due to apoptosis and OP-B could induce autophagy of HeLa cells. OP-B also induced the protein expression up-regulation of Beclin-1 and promoted LC3 I transformation LC3 II, which were representative proteins of autophagy. Furthermore, 3-MA, an inhibitor of autophagy, not only inhibited OP-B-mediated autophagy but also almost completely reversed the antiproliferative effect of OP-B, suggesting that the growth inhibition effect of OP-B was autophagy dependent. Western blotting demonstrated that OP-B inhibited the phosphorylation of Akt and its' downstream vital protein, such as mTOR and p70S6K. In addition, OP-B also induced the protein expression up-regulation of PTEN, which is a negative regulation protein for Akt/mTOR signaling pathway. However, OP-B did not affect the protein expression of total Akt. Collectively, the antitumor effects of OP-B were autophagy-dependent via repression Akt/mTOR signaling pathway. Therefore, OP-B is a prospective inhibitor of Akt/mTOR and may be used as an alternative compound to treat cervical carcinoma.

Objective To study the synergistic antitumor effects of quercetin and cisplatin in human prostate cancer PC3 cells and LNCaP cells.Methods Twelve h after PC3 cells or LNCaP cells were seeded,different dose of quercetin (10 μmol/L,20 μmol/L,40 μmol/L,80 μmol/L,160 μmol/L) or cisplatin (0.01 μmol/L,0.05 μmol/L,0.1 μmol/L,1 μmol/L,10 μmol/L),or quercetin (20 μmol/L) + cisplatin (0.01 μmol/L,0.05 μmol/L,0.1 μmol/L,1 μmol/L,10 μmol/L) were added for48 h and then the antiproliferative effects were detected with MTT assay.After incubated with quercetin (20 μmol/L) or cisplatin (0.05 μ mol/L),or quercetin (20 μ mol/L) + cisplatin (0.05 μmol/L) for48 h,cell cycle distribution and apoptosis of PC3 cells or LNCaP cells were detected by flow cytometer,PI and Annexin V staining.Protein expression was detected by Western blotting.Results After treatment with quercetin or cisplatin alone,the IC50 were (0.99 ± 0.13) μmol/L,(0.75 ± 0.09) μmol/L and (91.60 ± 6.10) μ mol/L,(72.90±4.70) μ mol/L for LNCaP cells or PC3 cells,respectively;The IC50 were (0.11±0.06)μ mol/L,(0.07±0.02) μmol/L for quercetin + cisplatin treatment (Compared with quercetin,P＜0.01 ;Compared with cisplatin,P＜0.05.After treatment with cisplatin or quercetin + cisplatin for 48 h,the S phase percent of LNCaP cells or PC3 cells were (22.4±2.7)％,(31.2±2.4)％ and (20.1±1.6)％,(31.0±2.5)％,respectively,(Compared with control,P＜0.05,however,treatment with quercetin alone has no significant difference (Compared with control,P＞0.05).After treatment with cisplatin or quercetin + cisplatin for 48 h,the apoptotic percent of LNCaP cells or PC3 cells were (14.8 ± 1.9) ％,(39.6 ± 3.1) ％ and (11.5± 1.2) ％,(34.1 ±3.3) ％,respectively,(compared with control,P ＜ 0.05,however,treatment with quercetin alone had no significant difference (compared with control,P＞0.05).After treatment with quercetin alone for 48 h,the activation of caspase-3,caspase-8 and caspase-9 were slightly increased,the expressions of Bax and p21 were up-regulated,the expressions of Bcl-2 and CDK2 were down-regulated.Furthermore,these effect of cisplatin and quercetin + cisplatin were significantly enhanced (compared with quercetin,P＜0.05;compared with quercetin,P＜0.01,respectively.Conclusions The combination modality with quercetin and cisplatin has a better treatment effect in vitro not only in androgen-dependent LNCaP cells but also in androgen-independent PC3 cells.

0.1 ?mol?L-1), inducing differentiation through enhancement of melanogenesis and increase of the activity of tyrosinase at lower doses(

OBJECTIVETo study the antiproliferative effects of beta-sitosterul and its mechanism in hepatoma HepG2 cells.

METHODCell proliferation was assessed by MTT assay. Cell cycle distribution, apoptosis and mitochondrial membrane potential were measured by high content screening (HCS). The protein expression of caspase-3, caspase-8, caspase-9, Bcl-2, Bax, tBid and cytochrome c in the HepG2 cells were evaluated by Western Blots.

RESULTbeta-Sitosterul exerted significant antiproliferative effects in HepG2 cells. Furthermore, beta-sitosterul also induced HepG2 cells apoptosis, lost mitochondrial membrane potential, activated caspase-3, caspase-8 and caspase-9, up-regulate Bax, tBid protein, down-regulation Bcl-2 protein. However, beta-sitosterul had hardly any effects on QSG7701 cells.

CONCLUSIONbeta-Sitosterul exerted antiproliferative effects and induced HepG2 cells apoptosis via mitochondrial pathway and membrane death receptor pathway.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Apoptosis Regulatory Proteins ; metabolism ; Carcinoma, Hepatocellular ; metabolism ; pathology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Hep G2 Cells ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Membrane Potential, Mitochondrial ; drug effects ; Sitosterols ; pharmacology

This study is to examine the effects of NNIspm-mediated cellular senescence of HepG2 cells and elucidate its potential molecular mechanism. Cellular senescence was detected with senescence-associated beta-galactosidase staining. Cell cycle distribution, intracellular fluorescence intensity and accumulation of intracellular reactive oxygen species (ROS) were detected by high content screening (HCS). Protein expression was detected by Western blotting. Polyamines content was analyzed by high performance liquid chromatography (HPLC). The results demonstrated that NNIspm significantly induced HepG2 cells senescence. This effect was due to the decrease of intracellular polyamines, the arrest at G0/G1 phase and an increase of ROS level. The molecular senescence marker p21 increased significantly after NNIspm treatment. In contrast, the protein expressions of Cyclin E and CDK2 were obvious down-regulation. The results indicated that cellular senescence induced by NNIspm was one of its antitumor mechanisms.

Aim To investigate the apoptotic mechanism and polyamine transporter recognition of 3-nitro-naphthalimide norspermine conjugate (NNINspm),a novel naphthalimide-polyamine conjugate, in HepG2 cells.Methods The cytotoxicity of NNINspm was assessed by MTT assay.Cell cycle distribution and apoptosis were measured by flow cytometry.The protein expression of cytochrome C,14-3-3,Bad,Bcl-xL,mTOR,p70S6K,Cdk4,p27~(kip1),Akt,Caspase-3,Caspase-9 was evaluated by Western blot.The translocation of Akt was detected by high content screening (HCS) analysis.Results NNINspm induced HepG2 cells apoptosis via Akt dephosphorylation and then triggered a series of signal events, such as Bad dephosphorylation, dissociation of 14-3-3 and Bad, and then binding to Bcl-xL,which finally resulted in mitochondrial disruption,cytochrome c release and caspase cascade activation.Furthermore,the NNINspm-mediated cell cycle arrest was due to mTOR and p70S6K dephosphorylation,Cdk4 down-regulation and p27~(kip1) up-regulation.Conclusion NNINspm induces HepG2 cell apoptosis via PI_3K/Akt signal pathway.