miR-24-3p promotes proliferation and inhibits apoptosis of porcine granulosa cells by targeting P27

Ovarian follicle development is associated with the physiological functions of granulosa cells(GCs),including proliferation and apoptosis.The level of miR-24-3p in ovarian tissue of high-yielding Yorkshire×Landrace sows was significantly higher than that of low-yielding sows.However,the functions of miR-24-3p on GCs are unclear.In this study,using flow cytometry,5-ethynyl-2′-de-oxyuridine(EdU)staining,and cell count,we showed that miR-24-3p promoted the proliferation of GCs increasing the proportion of cells in the S phase and upregulating the expression of cell cycle genes,moreover,miR-24-3p inhibited GC apoptosis.Mechanistically,on-line prediction,bioinformatics analysis,a luciferase reporter assay,RT-qPCR,and Western blot results showed that the target gene of miR-24-3p in proliferation and apoptosis is cyclin-dependent kinase inhibitor 1B(P27/CDKN1B).Furthermore,the effect of miR-24-3p on GC proliferation and apoptosis was attenuated by P27 overexpression.These findings suggest that miR-24-3p regulates the physiological functions of GCs.

Mechanism of stilbene glycosides on apoptosis of SH-SY5Y cells via regulating PI3K/AKT signaling pathway

Objective:To investigate the effects of stilbene glycoside(TSG)on okadaic acid-induced apoptosis in human neuroblastoma cells(SH-SY5Y)via the PI3K/AKT pathway.Methods:The optimal concentration of OA was screened by CCK-8 assay,and SH-SY5Y cells were divided into control group,model group,TSG group,LY294002 group and LY294002+TSG group.The proliferation and apoptosis in each group were detected by CCK-8 and TUNEL assays;Western blotting method and real-time fluorescence quantitative polymerase chain reaction was used to detect the expression of PI3K,P-PI3K(Y607),AKT,P-AKT(Ser473),Bcl-2 and Bax proteins.The relative protein expression was represented by P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax gray ratio.Results:CCK-8 screened the optimal concentration of OA as 40 nmol/L.Compared with the control group,the model group increased relative cell viability,decreased apoptosis rate,the pathway and apoptotic proteins expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax were decreased,and the mRNA expression levels of PI3K,AKT and Bcl-2 were decreased.Bax mRNA expression level increased(P<0.05);Compared with model group,TSG group increased relative cell viability,decreased apoptosis rate,increased protein expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT,Bcl-2/Bax,and increased mRNA expression levels of PI3K,AKT,and Bcl-2.Bax mRNA expression decreased(P<0.05),LY294002 group decreased relative cell viability,increased apoptosis rate,P-PI3K(Y607)/PI3K protein expression levels were significantly decreased(P<0.05),P-AKT(Ser473)/AKT and Bcl-2/Bax protein expression levels were significantly decreased,but there was no statistical significance,PI3K,AKT and Bcl-2 mRNA expression levels were decreased,and Bax mRNA expression levels were increased(all P<0.05);Compared with LY294002 group,LY294002+TSG group increased relative cell viability,decreased apoptosis rate,and the protein expression levels of P-PI3K(Y607)/PI3K,P-AKT(Ser473)/AKT and Bcl-2/Bax were increased.The mRNA expression levels of PI3K,AKT,Bcl-2 were increased,Bax was decreased(all P<0.05).Conclusion:Stilbene glycoside may alleviate okadaic acid-induced apoptosis in SH-SY5Y cells by interfering with the PI3K/AKT signaling pathway,which in turn regulates the expression of apoptotic factors such as Bcl-2 and Bax.

Overexpression of inhibinα(1-32)fusion protein promotes apoptosis and cell cycle arrest in a cervical cancer cell model(Hela cells)

Inhibins play important roles in the reproductive system. To evaluate whether inhibin α (1-32) fusion protein plays a role in cervical cancer growth, the plasmid pVAX-inhα was constructed and its effect on proliferation and apoptosis of the human cervical cancer cell line (Hela) was checked by flow cytometry and real-time PCR. The expression and localization of inhibin α protein were detected by RT-PCR and confocal mi- croscopy which showed that inhibin α protein was expressed and localized in the nucleus of Hela cells. Over ex- pression of inhibin α gene significantly induced cell apoptosis and ceased S phase of cell cycle. Furthermore, cell proliferation was significantly suppressed 96 h post-transfection and mRNA level of anti-apoptosis genes (Bcl-2, NFκB) were decreased but pro-apoptosis genes (Bax, wild type p53) and inhibin co receptor (TGFβR3) were increased, indicating that inhibin, through its co-receptor, might activate apoptotic and cell growth cascades which regulate proliferation and apoptosis in Hela cells. These results suggest that inhibin α (1-32) fusion pro- tein, located in the cell nucleus, can regulate Hela cells growth and apoptosis by induction of apoptotic pathways such as NFκB, Bcl-2 and p53 families. These findings may have a significant impact on future research regarding cervical cancer cell lines.

3-Methyladenine potentiates paclitaxel-induced apoptosis and phosphorylation of cyclin-dependent kinase 1 at thr161 in nasopharyngeal carcinoma cell

Background:Nasopharyngeal carcinoma(NPC)exhibits a significant prevalence in the southern regions of China,and paclitaxel(PTX)is frequently employed as a medication for managing advanced NPC.However,drug resistance is typically accompanied by a poor prognosis.Exploring the synergistic potential of combining multiple chemotherapeutic agents may represent a promising avenue for optimizing treatment efficacy.Methods:This study investigated whether 3-Methyladenine(3-MA)could potentiated the effect of PTX and its potential molecular mechanism.Samples were divided into the following categories:Negative control(NC)with the solvent dimethyl sulfoxide(DMSO,0.5%v/v),PTX(400 nM),3-MA(4 mM),and PTX(400 nM)+3-MA(4 mM).The viability of NPC cells was assessed using both the cell counting kit-8(CCK-8)assay and the colony formation assay.Microscopic observation was performed to identify morphological cell changes.Flow cytometry was used to assess cell cycle status,mitochondrial membrane potential(MMP),and apoptotic cells.Western blotting was conducted to quantify the protein expression.Results:3-MA enhanced PTX-specific inhibition of NPC cell proliferation.PTX,either alone or in combination with 3-MA,caused cell cycle halt at the G2/M phase in the majority of NPC cells,and the combination treatment of PTX with 3-MA induced a higher rate of NPC cell death compared to PTX alone.Western blotting results revealed the combination of PTX with 3-MA heightened activation of cyclin-dependent kinase 1(CDK1),a key molecule in shifting cells from mitotic arrest to apoptosis,led to a reduction in Myeloid Cell Leukemia 1(MCL-1)expression and an increase in Poly(ADP-ribose)polymerase(PARP)cleavage.Conclusion:The concurrent administration of PTX with 3-MA effectively enhances PTX’s inhibitory impact on NPC and activates the apoptosis signal regulated by CDK1.

Paclitaxel induces human KOSC3 oral cancer cell apoptosis through caspase pathways

Background:Paclitaxel is a compound derived from Pacific yew bark that induces various cancer cell apoptosis.However,whether it also has anticancer activities in KOSC3 cells,an oral cancer cell line,is unclear.Methods:3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,flow cytometry,and western blotting assays were carried out to assess cell viability,subG1 phase of the cell cycle,and apoptosis-related protein expression,respectively.Results:Ourfindings indicate that paclitaxel could inhibit cell viability and increase the expression of apoptotic markers,including plasma membrane blebbing and the cleavage of poly ADP-ribose polymerase in KOSC3 cells.Also,the treatment with paclitaxel remarkably elevated the percentage of the subG1 phase in KOSC3 cells.In addition,treatment with a pan-caspase inhibitor could recover paclitaxel-inhibited cell viability.Moreover,caspase-8,caspase-9,caspase-7,and BH3 interacting domain death agonist(Bid)were activated in paclitaxel-treated KOSC3 cells.Conclusions:Paclitaxel induced apoptosis through caspase cascade in KOSC3 cells.

3-N-Butylphthalide mitigates high glucose-induced injury to Schwann cells:association with nitrosation and apoptosis

A high glucose state readily causes peripheral axon atrophy, demyelination, loss of nerve fiber function, and delayed regeneration. However, few studies have examined whether nitration is also critical for diabetic peripheral neuropathy. Therefore, this study investigated the effects of high glucose on proliferation, apoptosis, and 3-nitrotyrosine levels of Schwann cells treated with butylphthalide. In addition, we explored potential protective mechanisms of butylphthalide on peripheral nerves. Schwann cells were cultured in vitro with high glucose then stimulated with the peroxynitrite anion inhibitors uric acid and 3-n-butylphthalide for 48 hours. Cell Counting Kit-8 and flow cytometry were used to investigate the effects of uric acid and 3-n-butylphthalide on proliferation and apoptosis of Schwann cells exposed to a high glucose environment. Effects of uric acid and 3-n-butylphthalide on levels of 3-nitrotyrosine in Schwann cells were detected by enzyme-linked immunosorbent assay. The results indicated that Schwann cells cultured in high glucose showed decreased proliferation, but increased apoptosis and intracellular 3-nitrotyrosine levels. However, intervention with uric acid or 3-n-butylphthalide could increase proliferation of Schwann cells cultured in high glucose, and inhibited apoptosis and intracellular 3-nitrotyrosine levels. According to our data, 3-n-butylphthalide may inhibit cell nitrification and apoptosis, and promote cell proliferation, thereby reducing damage to Schwann cells caused by high glucose.

Parthenolide protects human lens epithelial cells from oxidative stress-induced apoptosis via inhibition of activation of caspase-3 and caspase-9

The apoptosis of lens epithehal cells has been proposed as the common basis of cataract formation, with oxidative stress as the major cause. This study was performed to investigate the protective effect of the herbal constituent parthenolide against oxidative stress-induced apoptosis of human lens epithelial （HLE） cells and the possible molecular mechanisms involved. HLE cells （SRA01-04） were incubated with 50 μM H2O2 in the absence or presence of different doses of parthenolide （10, 20 and 50 μM）. To study apoptosis, the cells were assessed by morphologic examination and Annexin V-propidium iodide double staining flow cytometry; to investigate the underlying molecular mechanisms, the expression of caspase-3 and caspase-9 were assayed by Western blot and quantitative RT-PCR, and the activities of caspase-3 and caspase-9 were measured by a Chemicon caspase colorimetric activity assay kit. Stimulated with H202 for 18 h, a high fraction of riLE cells underwent apoptosis, while in the presence ofparthenolide of different concentrations, dose-dependent blocking of HLE cell apoptosis was observed. The expression of caspase-3 and caspase-9 induced by H202 in HLE cells was significantly reduced by parthenolide both at the protein and mRNA levels, and the activation ofcaspase-3 and caspase-9 was also suppressed by parthenolide in a dose-dependent manner. In conclusion, parthenolide prevents HLE cells from oxidative stress-induced apoptosis through inhibition of the activation ofcaspase-3 and caspase-9, suggesting a potential protective effect against cataract formation.

Ginsenoside Rh_2 Showing Ability to Induce Apoptosis in HeLa Cells

This paper deals with the inhibitory mechanisms of ginsenoside \{G Rh 2\} on the growth of tumor cells. \{G Rh 2\} significantly inhibited the proliferation of human cervical adenocarcinoma HeLa cells in a time and dose dependent manner. G Rh 2 induced apoptotic manifestations in HeLa cells as evidenced by the changes in the cell morphology, the DNA fragmentation and the activation of caspases. Caspase inhibitors, caspase family inhibitor, z Val Ala Asp fmk(z VAD fmk); caspase 1 inhibitor, Ac Tyr Val Ala Asp chloromethyl ketone(Ac YVAD cmk); caspase 3 inhibitor, z Asp Glu Val Asp fmk(z DEVE fmk) and caspase 8 inhibitor, \{z Ile \}Glu Asp fmk(z IETD fmk) effectively attenuated G Rh 2 induced cell death. The activities of caspase 1 and caspase 3 were increased in the G Rh 2 induced apoptotic process. However, caspase inhibitors can not inhibit G Rh - 2 induced cell death completely. These results suggest that G Rh 2 induced cell death is mediated by the activation of caspase cascade, but there might be some other pathways for induction of this apoptosis.

Long Non-coding RNA MEG3 Induces Renal Cell Carcinoma Cells Apoptosis by Activating the Mitochondrial Pathway

Summary： This study aimed to examine the effect of long non-coding RNA （LncRNA） MEG3 on the biological behaviors of renal cell carcinoma （RCC） cells 786-0 and the possible mechanism. MEG3 expression levels were detected by RT-qPCR in Rmaor tissues and adjacent non-tumor tissues from 29 RCC patients and in RCC lines 786-0 and SN12 and human embryonic kidney cell line 293T. Plasmids GV144-MEG3 （MEG3 overexpression plasmid） and GV144 （control plasmid） were stably transfected into 786-0 cells by using lipofectamine 2000. Cell viabilities were determined by MTT, cell apoptosis rates by flow cytometry following PE Annexin V and 7AAD staining, apoptosis-related protein expressions by Western blotting, and Bcl-2 mRNA by RT-qPCR in the transfected cells. The results showed that MEG3 was evidently downregulated in RCC tissues （P〈0.05） and RCC cell lines （P〈0.05）. The viabilities of 786-0 cells were decreased significantly after transfection with GV144-MEG3 for over 24 h （P〈0.05）. Consistently, the apoptosis rate was significantly increased in 786-0 cells transfected with GV144-MEG3 for 48 h （P〈0.05）. Furthermore, overexpression of MEG3 could reduce the expression of Bcl-2 and procaspase-9 proteins, enhance the expression of cleaved caspase-9 protein, and promote the release of cytochrome c protein to cytoplasm （P〈0.05）. Additionally, Bcl-2 mRNA level was declined by MEG3 overexpression （P〈0.05）. It was concluded that MEG3 induces the apoptosis of RCC cells possibly by activating the mitochondrial pathway.

Alisol B acetate induces apoptosis of SGC7901 cells via mitochondrial and phosphatidylinositol 3-kinases/Akt signaling pathways

AIM： To examine the effect of alisol B acetate on the growth of human gastric cancer cell line SGC7901 and its possible mechanism of action.METHODS： The cytotoxic effect of alisol B acetate on SGC7901 cells was measured by 3-（4,5-dimethylthiazol- 2-yl）-2,5-diphenyltetrazolium bromide （MI-I-） assay. Phase-contrast and electron microscopy were used to observe the morphological changes. Cell cycle and mitochondrial transmembrane potential （A^Pm） were determined by flow cytometry. Western blotting was used to detect the expression of apoptosis-regulated gene Bcl-2, Bax, Apaf-1, caspase-3, caspase-9, Akt, P-Akt and phosphatidylinositol 3-kinases （PI3K）.RESULTS： Alisol B acetate inhibited the proliferation of SGC7901 cell line in a time- and dose-dependent manner. PI staining showed that alisol B acetate can change the cell cycle distribution of SGC7901, increase the proportion of cells in G0-G1 phase and decrease the proportion of S phase cells and G2-M phase cells. Alisol B acetate at a concentration of 30 pmol/L induced apoptosis after 24, 48 and 72 h incubation, with occurrence rates of apoptotic cells of 4.36%, 14.42% and 21.16%, respectively. Phase-contrast and electron microscopy revealed that the nuclear fragmentation and chromosomal condensed, cells shrank and attachment loss appeared in the SGC7901 treated with alisol B acetate. Apoptosis of SGC7901 cells was associated with cell cycle arrest, caspase-3 and caspase-9 activation, loss of mitochondrial membrane potential and up-regulation of the ratio of Bax/Bcl-2 and inhibition of the PI3K/Akt.CONCLUSION： Alisol B acetate exhibits an antiproliferative effect in SGC7901 cells by inducing apoptosis. Apoptosis of SGC7901 cells involves mitochondria-caspase and PI3K/Akt dependent pathways.

Apoptosis of pancreatic cancer BXPC-3 cells induced by indole-3-acetic acid in combination with horseradish peroxidase

AIM： To explore the mechanisms underlying the apoptosis of human pancreatic cancer BXPC-3 cells induced by indole-3-acetic acid （IAA） in combination with horseradish peroxidase （HRP）. METHODS： BXPC-3 cells derived from human pancreatic cancer were exposed to 40 or 80 μmol/L IAA and 1.2 μg/mL HRP at different times. Then, Mn- assay was used to detect the cell proliferation. Flow cytometry was performed to analyze cell cycle. Terminal deoxynucleotidyl transferasemediated dUTP nick end labeling assay was used to detect apoptosis. 2,7-Dichlorofluorescin diacetate uptake was measured by confocal microscopy to determine free radicals. Level of malondialdehyde （MDA） and activity of superoxide dismutase （SOD） were measured by biochemical methods. RESULTS： IAA/HRP initiated growth inhibition of BXPC-3 cells in a dose- and time-dependent manner. Flow cytometry revealed that the cells treated for 48 h were arrested at G1/G0. After exposure to 80 μmol/L IAA plus 1.2 μg/mL HRP for 72 h, the apoptosis rate increased to 72.5‰, which was nine times that of control. Content of MDA and activity of SOD increased respectively after treatment compared to control. Meanwhile, IAA/HRP stimulated the formation of free radicals. CONCLUSION： The combination of IAA and HRP can inhibit the growth of human pancreatic cancer BXPC-3 cells in vitro by inducing apoptosis.

Tanshinone IIA Could Inhibit Pancreatic Cancer BxPC-3 Cells through Increasing PERK, ATF6, Caspase-12 and CHOP Expression to Induce Apoptosis

Tanshinone IIA (Tan-IIA) is extracted from Dan-Shen. Tan-IIA could inhibit human pancreatic cancer BxPC-3 cells through decreasing TCTP, Mcl-1 and Bcl-xl expression in vitro. Our previous study showed that Tan-IIA can inhibit hepatocellular carcinoma hep-J5 cells and human breast cancer BT-20 cells through inducing endoplasmic reticulum (ER) stress. In the present study, we investigated the ER stress related protein expressions in human pancreatic cancer BxPC3 cells were treated with Tan-IIA. The ER stress related protein expressions in human pancreatic cancer BxPC-3 cells were evaluated by western blotting. The results showed that Tan-IIA can increase the protein expressions of PERK, ATF6, Caspase-12 and CHOP, but decrease Bip, PDI, Calnexin, Calreticulin and Bcl-2 expression. These findings indicated that Tan-IIA can inhibit human pancreatic cancer BxPC-3 cells by inducing ER stress to induce apoptosis.

Phosphoinositide 3-Kinase/Akt and Nuclear Factor-κB Are Involved in Staphylococcus Aureus-induced Apoptosis in U937 Cells

Objective To explore the mechanisms involved in Staphylococcus aureus （S. aureus） invading human monocytic U937 cells. Methods S. aureus were added to U937 cells at multiplicity of infections （MOI） of 20：1 for 0, 15, 30, 60, and 90 minutes, respectively. Cell apoptosis was analyzed with Hoechst 33258 staining and Annexin V-fluorescein isothiocyanate （FITC）/propidium iodide （PI） flow cytometry analysis. Akt and nuclear factor-κB （NF-κB） activities were detected by Western blotting. Results Infection of U937 cells with S. aureus induced rapid cell death in a time-dependent manner, and the cells displayed characteristic features of apoptosis. S. aureus-induced apoptosis was associated with a prominent downregulation of activated （phosphorylated） Akt and NF-κB. The inhibition of phosphorylated Akt by LY294002 led to the inhibition of NF-κB in a dose-dependent manner. Inhibition of Akt with LY294002 caused further increase in apoptosis of U937 cells. Conclusions S. aureus can stimulate the apoptosis of U937 ceils. S. aureus induces apoptosis of U937 cells by inhibiting Akt-regulated NF-κB.

Demethylation of miR-34a upregulates expression of membrane palmitoylated proteins and promotes the apoptosis of liver cancer cells

BACKGROUND Liver cancer is a common cancer and the main cause of cancer-related deaths worldwide.Liver cancer is the sixth most common cancer in the world.Although miR-34a and palmitoyl membrane palmitoylated protein(MPP2)are reportedly involved in various cell processes,their precise roles in liver cancer are still unclear.AIM To investigate the expression of micro RNA 34a(miR-34a),methylation of the miR-34a promoter and the expression of MPP2 in liver cancer cells and their related mechanisms.METHODS Together,78 cases of liver cancer tissues and 78 cases of adjacent tissues were collected.The methylation degree of miR-34a promoter in liver cancer/paracancerous tissue and liver cancer cells/normal liver cells,and the expression levels of miR-34a and MPP2 in the above samples were detected.Demethylation of liver cancer cells or transfection of liver cancer cells with miR-34a mimetic was performed.The MPP2 overexpression vector was used to transfect liver cancer cells,and the changes in proliferation,invasion,apoptosis,migration,and other biological functions of liver cancer cells after the above interventions were observed.Double luciferase reporter genes were used to detect the targeting relationship between miR-34a and MPP2.RESULTS Clinical samples showed that the expression levels of miR-34a and MPP2 in liver cancer tissues were lower than those in the normal tissues.The methylation degree of miR-34a promoter region in liver cancer cells was higher than that in normal liver cells.After miR-34a demethylation/mimetic transfection/MPP2 overexpression,the apoptosis of liver cancer cells was increased;the proliferation,invasion and migration capabilities were decreased;the expression levels of caspase 3,caspase 9,E-cadherin,and B-cell lymphoma 2(Bcl-2)-associated X protein were increased;and the expression levels of Bcl-2,N-cadherin,andβ-catenin were decreased.Double luciferase reporter genes confirmed that MPP2 is targeted by miR-34a.Rescue experiments showed that small interfering MPP2 could counteract the promoting effect of miR-34a demethylation on apoptosis and the inhibitory effect on cell proliferation,invasion,and migration.CONCLUSION miR-34a demethylation upregulates the expression level of MPP2 in liver cancer cells and promotes the apoptosis of liver cancer cells.miR-34a demethylation is a potential method for liver cancer treatment.

TRICHOSTATIN A INHIBITS PROLIFERATION,INDUCES APOPTOSIS AND CELL CYCLE ARREST IN HELA CELLS

Objective： The histone deacetylase inhibitors （HDACIS） have been shown to inhibit cancer cell proliferation, stimulate apoptosis, an induce cell cycle arrest. Our purpose was to investigate the antiproliferative effects of a HDACI, trichostatin A （TSA）, against human cervical cancer cells （HeLa）. Methods： HeLa cells were treated in vitro with various concentrations of TSA. The inhibitory effect of TSA on the growth of HeLa cells was measured by MTT assay. To detect the characteristic of apoptosis chromatin condensation, HeLa cells were stained with Hoechst 33258 in the presence of TSA. Induction of cell cycle arrest was studied by flow cytometry. Changes in gene expression of p53, p21wafl and p27Kipl were studied by semiquantitative RT-PCR. Results： TSA inhibited cell growth in a time- and dose-dependent manner. Hoechst 33258 staining assay showed that TSA induced apoptosis. Cell cycle analysis indicated that treatment with TSA decreased the proportion of cells in S phase and increased the proportion of cells in G0/G1 and/or G2/M phases of the cell cycle. This was concomitant with overexpression of genes related to malignant phenotype, including an increase in p53, p21wall and p27Kipl. Conclusion： These results suggest that TSA is effective in inhibiting growth of HeLa cells in vitro. The findings raise the possibility that TSA may prove particularly effective in treatment of cervical cancers.

Effects of Panax notoginseng saponins on apoptosis induced by hydrogen peroxide in cultured rabbit bone marrow stromal cells via altering the oxidative stress level and down-regulating caspase-3

Objective： To investigate the effects of Panax notoginseng saponins （PNS） on hydrogen peroxide （H2O2）-induced apoptosis in cultured rabbit bone marrow stromal cells （BMSCs）. Methods： The effects of different concentrations of PNS on proliferation and early osteoblast differentiation of BMSCs were determined by the MTT assay and an alkaline phosphatase （ALP） assay. An optimal effective concentration of PNS was determined and used in subsequent experiments. The cultured BMSCs were divided into three groups： untreated control, H2O2 treated, and PNS pretreatment of H2O2 treated. The oxidative stress level was assessed by superoxide dismutase （SOD） and malondialdehyde （MDA） assays. Flow cytometry was used to determine BMSC apoptosis by staining with annexinV-FITC/propidium iodide （PI）. The activity of caspase-3 enzyme was measured by spectrofluorometry. Results： PNS （0.1g/L） significantly increased both BMSC proliferation rate and ALP activity, while it decreased the indicators of oxidative stress, caspase-3 activity, and the apoptosis rate of BMSCs induced by H2O2.. Conclusion： PNS, acting as a biological antioxidant, had a protective effect on H2O2-induced apoptosis in cultured rabbit BMSCs by decreasing oxidative stress and down-regulating caspase-3.

The multikinase inhibitor sorafenib induces caspase-dependent apoptosis in PC-3 prostate cancer cells

The present study investigated the effects of the multikinase inhibitor sorafenib on androgen-independent can- cer cells viability and intracellular signaling. Human androgen-independent PC-3 prostate cancer cells were treated with sorafenib. At concentration that suppresses extracellular signal-regulated kinase phosphorylation, sorafenib treatment reduced the mitochondrial transmembrane potential. Sorafenib also down-modulated the levels of mye- loid cell leukemia 1, survivin and cellular inhibitor of apoptosis protein 2. Sorafenib induced caspase-3 cleavage and the mitochondrial release of cytochrome c. However, no nuclear translocation of apoptosis inducing factor was detected after treatment and the pan-caspase inhibitor Z-VAD-FMK had an obvious protective effect against the drug. In conclusion, sorafenib induces apoptosis through a caspase-dependent mechanism with down-regulated antiapoptotic proteins in androgen-independent prostate cancer cells in vitro.

Effects of ATRA, Acitretin and Tazarotene on Growth and Apoptosis of Tca8113 Cells

Summary：To investigate the effects of ATRA, acitretin and tazarotene on the growth and apoptosis of human tongue squamous cell carcinoma cell line Tca8113. The effect of retinoids on growth of Tca8113 cells in vitro was examined by MTT assay and Trypan blue exclusion assay. Cell cycle analysis, early apoptosis analysis with double staining with Annexin V-FITC and PI, and active caspase-3 analysis with the staining of FITC-conjugated monoclonal rabbit anli-active caspase-3 antibody were made by flow cytometer. Streptavidin-biotin complex （SABC） immunocytochemical assays were employed for the detections of Bax/Bcl-2 proteins expressions. Our results showed that the retinoids inhibited growth of Tca8113 cells in a dose-and time-dependent manner with maximal inhibition 24 h after treatment of 10 5 mol/L. 10^-5 mol/L retinoids altered cell cycle distribution of Tca8113 cells, revealing an increase in G0/G1-phase population, a decrease in S-phase population and the inhibition of G1/S switching. 10^-5 mol/L retinoids significantly induced apoptosis of Tca8113 cells （all P〈0.05）, elevated the cells population with detectable active caspase-3 （P〈 0.05 for all）, increased the number of cells forming Bax and decreased the number of cells forming Bcl-2 significantly （all P〈0.05）. Acitretin played a most prominent role among the retinoids. It is concluded that the inhibition of cell cycle progress of Tca8113 cells by ATRA, acitretin and tazarotene is one of the possible mechanisms for proliferation arrest of TcaS113 cells elicited by the retinoids. The retinoids mediate apoptosis in TcaS113 cells that may be caspase-dependent through mitochondria pathway. High concentration retinoids inhibit growth of Tca8113 cells in vitro by interfering with proliferation and inducing apoptosis of cells. Acitretin may be an alternative medicine for the prevention and treatment of tongue squamous cell carcinoma.

Adenosine triphosphate-sensitive potassium channel opener protects PC12 cells against hypoxia-induced apoptosis through PI3K/Akt and Bcl-2 signaling pathways

Although previous studies have shown the neuroprotective effects of the adenosine triphosphate （ATP）-sensitive potassium （KATP） channel opener against ischemic neuronal damage, little is known about the mechanisms involved. Phosphatidylinositol-3 kinase （PI3K）/v-akt murine thy-moma viral oncogene homolog （Akt） and Bcl-2 are thought to be important factors that mediate neuroprotection. The present study investigated the effects of KATP openers on hypoxia-induced PC12 cell apoptosis, as well as mRNA and protein expression of Akt and Bcl-2. Results demon-strated that pretreatment of PC12 cells with pinacidil, a KATP opener, resulted in decreased PC12 cell apoptosis following hypoxia, as detected by Annexin-V fluorescein isothiocyanate/ propidium iodide double staining flow cytometry. In addition, mRNA and protein expression of phosphorylated Akt （p-Akt） and Bcl-2 increased, as detected by immunofluorescence, Western blot analysis, and reverse-transcription polymerase chain reaction. The protective effect of this preconditioning was attenuated by glipizide, a selective KATP blocker. These results demonstrate for the first time that the protective mechanisms of KATP openers on PC12 cell apoptosis following hypoxia could result from activation of the PI3K/Akt signaling pathway, which further activates expression of the downstream Bcl-2 gene.

Effect of STAT3 siRNA-Induced Inhibition of STAT3 Gene Expression on the Growth and Apoptosis of Lewis Lung Cancer Cells

OBJECTIVE To determine the effect of short interference RNA （siRNA） against STAT3 induced inhibition of STAT3 gene expression and on the growth and apoptosis of Lewis lung cancer cells. METHODS pSilencer 2.1-U6 STAT3 siRNA against STAT3-mRNA was synthesized, Lewis lung cancer cells were divided into 3 groups： vehicle, plasmid, and STAT3 siRNA in which the ceils were treated with RPMI- 1640 culture media, or transfected with pSilencer empty vector, or pSilencer STAT3 siRNA, Semiquantitative RT-PCR and Western blot analysis of STAT3 gene expression in the cells was performed 72 h after transfection, MFr assay for cell proliferation, flow cytometry and DNA laddering electrophoresis were used for determination of cell proliferation and apoptosis, RESULTS STAT3 was markedly expressed at both the mRNA and protein levels in the cells treated with RPMI-1640 media or transfected with the plasmid vector, whereas STAT3 expression was significantly reduced in cells treated with STAT3 siRNA, These findings suggest that STAT3 siRNA effectively inhibited STAT3 expression. Transfection of the cells with STAT3 siRNA resulted in significant cellular growth inhibition and enhanced apoptosis, CONCLUSION Transfection of Lewis lung cancer cells with synthetic STAT3 siRNA resulted in effective inhibition of STAT3 gene expression at both protein and mRNA levels, leading to induced apoptosis and growth suppression.