Synergistic effect of decitabine and valproic acid on apoptosis and cell cycle arrest at G0/G1 phase in gastric cancer MGC-803 cells

AIM: To investigate the synergistic effect of decitabine (DCA) and valproic acid (VPA) on apoptosis and cell cycle arrest at G₀/G₁ phase in gastric cancer MGC-803 cells. METHODS: Gastric cancer MGC-803 cells were used in the study and divided into the following groups according to the treatment with different drugs for 72 h: DCA 1.5 μmol/L,DCA 3.0 μmol/L, VPA 1.5 mmol/L, DCA 1.5 μmol/L+VPA 1.5 mmol/L and DCA 3.0 μmol/L+VPA 1.5 mmol/L. The early and late apoptotic rates were detected by annexin V and PI staining. The cell cycle was also determined by flow cytometry. The relative nm23-H1 mRNA expression level was measured by real-time quantitative PCR. RESULTS: The apoptotic rates in VPA 1.5 mmol/L+DCA 1.5 μmol/L group (early: 33.58%±3.88%; late: 31.52%±4.20%) and VPA 1.5 mmol/L+DCA 3.0 μmol/L group (early: 42.61%±4.23%; late: 38.01%±3.86%), the percentages of the cells in G₀/G₁ phase in VPA 1.5 mmol/L+DCA 1.5 μmol/L group (61.55%±2.38%) and VPA 1.5 mmol/L+DCA 3.0 μmol/L group (66.75%±2.48%), and the relative nm23-H1 mRNA expression levels in VPA 1.5 mmol/L +DCA 1.5 μmol/L group (1.84±0.46) and VPA 1.5 mmol/L+DCA 3.0 μmol/L group (3.02±0.36) were all significantly higher than those in the corresponding concentrations of single drug treatment groups (P<0.01). CONCLUSION: Synergistic effect of VPA and DCA on apoptosis and cell cycle arrest in gastric cancer MGC-803 cells is possibly via inactivation of nm23-H1 gene expression.     

Effects of marine fungal metabolites 1386A from the South China Sea on proliferation,apoptosis and mitochondrial membrane potential in gastric cancer cell line MCG-803

AIM: To investigate the effects of marine fungal metabolites 1386A from the South China Sea(1386A) on gastric cancer cell line MCG-803.METHODS: The effects of 1386A on cell viability and cell growth were detected by MTT method and colony-forming assay, respectively. The changes of cell cycle, cell apoptosis and mitochondrial membrane potential were determined by flow cytometry.RESULTS: The IC₅₀ of cell viability on MCG-803 cells after treated with 1386A for 24 h, 48 h and 72 h was 29.70 μmol/L, 14.07 μmol/L or 13.47 μmol/L, respectively. The IC₅₀ of the cell growth on MCG-803 cells after treated with 1386A for 48 h was 3.27 μmol/L. After treated with 1386A for 48 h, the MCG-803 cells in S stage was increased from 25.6% to 56.8%. After treated with 1386A for 24 h, the early apoptosis of MCG-803 cells was increased from 3.34% to 8.39%, and the mitochondrial membrane potential of MCG-803 cells was decreased by 56.26%.CONCLUSION: 1386A has an inhibitory effect on the cell growth in MCG-803 cells through the mitochondrial pathway.     

Indomethacin induces gastric cancer cell apoptosis through Akt/GSK3β/NAG-1 pathway

AIM: To investigate whether indomethacin induces gastric cancer cell apoptosis through Akt/GSK3β/NAG-1 pathway.METHODS: Gastric cancer cell line MGC-803 was used in the study. Cell viability was measured by MTT method. Hoechst 33258 nuclear staining and flow cytometry analysis were used to determine apoptosis. The protein expression level was examined by Western blotting. RESULTS: Indomethacin induced MGC-803 cell apoptosis via caspase-dependent pathway. Indomethacin inhibited Ser473-Akt and Ser9-GSK3β phosphorylation and up-regulated the expression of non-steroidal anti-inflammatory drug-activated gene-1 (NAG-1). Inhibition of PI3K or Akt alone also increased NAG-1 expression. Moreover, the effect of indomethacin on NAG-1 expression was abolished by pretreatment of the cells with GSK3β inhibitor SB216763. CONCLUSION: Indomethacin induces gastric cancer cell apoptosis through Akt/GSK3β/NAG-1 pathway.     

Baicalein inhibits proliferation and migration of gastric cancer MGC-803 cells

AIM: To investigate the effects of baicalein (BAI) on the proliferation and migration of gastric cancer MGC-803 cells and the mechanisms. METHODS: After MGC-803 cells were treated with BAI at different concentrations, the viability of the MGC-803 cells was tested by MTT assay. The cell colony formation ability were detected by plate colony formation assay. Wound-healing and Transwell cell migration assays were used to test the migration ability of the MGC-803 cells. The concentration of 12-hydroxyeicosatetraenoic acid (12-HETE) was measured by ELISA. The protein levels of platelet type 12-lipoxygenase (p12-LOX), vascular endothelial growth factor (VEGF), p-ezrin and epithelial-mesenchymal transition (EMT) markers in MGC-803 cells were determined by Western blot. RESULTS: BAI significantly inhibited the proliferation, plate colony formation and migration abilities of the MGC-803 cells (P<0.05 or P<0.01), down-regulated the concentration of p12-LOX metabolite 12-HETE significantly (P<0.05 or P<0.01), decreased the protein levels of p12-LOX, VEGF, p-ezrin, vimentin and Snail (P<0.05 or P<0.01), and increased the protein expression of E-cadherin (P<0.01). CONCLUSION: BAI suppresses the proliferation and migration abilities of gastric cancer MGC-803 cells effectively. These effects of BAI may be related to regulating the protein levels of p12-LOX, VEGF, p-ezrin and EMT-related proteins.     

Fucoidan sulfate promotes apoptosis of gastric cancer cells by regulating expression of HDAC1

AIM:To study the effects of fucoidan sulfate on the apoptosis of gastric cancer cells, and to explore its relationship with histone deacetylase 1 (HDAC1). METHODS:The effects of fucoidan sulfate on the viability of gastric cancer BGC-823 cells were measured by MTT assay. The cells were divided into si-HDAC1 group, si-NC group and fucoidan+pcDNA 3.1-HDAC1 group and fucoidan+pcDNA 3.1 group. The transfection were performed by liposome method. The apoptosis was analyzed by flow cytometry. The protein expression of HDAC1, Bcl-2 and Bax was determined by Western blot. The mRNA expression of HDAC1 was detected by RT-qPCR. RESULTS:Compared with the control cells, the inhibitory rates of the cell viability by fucoidan sulfate (0.2, 0.4, 0.6, 0.8 and 1.0 g/L) were increased signi-ficantly (P<0.05). The appropriate concentration was 0.6 g/L. Compared with control group, the expression of HDAC1 at mRNA and protein levels in fucoidan sulfate group was significantly down-regulated, while the apoptotic rate was significantly increased (P<0.05). Knock-down of HDAC1 expression significantly up-regulated the apoptotic rate, while over-expression of HDAC1 reversed the apoptosis-promoting effect of fucoidan sulfate on the BGC-823 cells. CONCLUSION:Fucoidan sulfate promotes apoptosis of gastric cancer cells. The mechanism may be related to the direct inhibition of HDAC1, which provides support for the clinical application of fucoidan sulfate.     

CpG-oligodeoxynucleotides induce differentiation and apoptosis in HL60 cells

AIM: To investigate the differentiative and apoptotic effect of CpG-oligodeoxynucleotides on HL60 cells and its mechanism. METHODS: After HL60 cells were exposed to synthetic CpG-oligodeoxynucleotides,non-CpG-oligodeoxynucleotides or ZpG-oligodeoxynucleotides for 72 hours, respectively, the inhibition of HL60 cells were detected using MTT method, NBT test was used and CD14 expression were determined.,Apotosis of HL60cells were mensurated with flow cytometry and transmission electron microscope, and caspase 3，Bcl-2 and Bax expres-sion of HL60 cells treated with oligodeoxynucletides were detected using immunohistochemistry RESULTS: Treatment with CpG-oligodeoxynucleotides induced the differentiation and apoptosis in HL60 cells, but non-CpG-oligodeoxynucleotide and ZpG-oligodeoxynucleotide had no effect on HL60 cells. CONCLUSION: CpG-oligodeoxynucleotides can induce the differentiation and apoptosis in HL60 cells. It may provide a new approach for the immunological treatment of leukemia.     

Effect of ruthenium-polypyridine complex on apoptosis of gastric cancer SGC-7901 cells

AIM:To study the effect of ruthenium-pyridine complex Ru1 on apoptosis of gastric cancer SGC-7901 cells. METHODS:MTT assay and crystal violet staining method were used to detect the viability and cell number of SGC-7901 cells treatment with Ru1. Annexin V-FITC and PI staining was performed to test the apoptosis rate of SGC-7901 cells. The protein expression of Bax and Bcl-2 was detected by Western blot. RESULTS:The results of MTT assay and crystal violet staining showed that the ruthenium-pyridine complexes significantly reduced the viability and cell number of SGC-7901 cells. Treatment with Ru1 for 24 h significantly increased the apoptotic rate of SGC-7901 cells (P<0.05). Ru1 up-regulated the expression of Bax protein and down-regulated the expression of Bcl-2 protein in the SGC-7901 cells (P<0.05). CONCLUSION:Ru1 induces apoptosis of SGC-7901 cells by affecting the expression of Bax and Bcl-2 proteins.     

Berberine promotes apoptosis of human breast cancer cells by regulating miRNA-146a

ATM: To observe the effect of berberine on apoptosis of MCF-7 cells and its potential mechanism. METHODS: The MCF-7 cells were divided into control group and the groups with 3 different doses of berberine. The cell viability was detected by MTT assay, while the cell apoptosis was measured by Hoechst 33258 staining and flow cytometry assay. The protein levels of p-P65, Bax and Bcl-2 were Western blot. The levels of microRNA-146a(miRNA-146a) in the MCF-7 cells were detected by RT-qPCR. The miRNA-146a siRNA was transfected to the MCF-7 cells after an evaluation of transfection efficacy, which was co-incubated with berberine to observe its effects on the mRNA levels of Bax and Bcl-2. RESULTS: Compared with control group, the cell viabilities were decreased significantly in medium and high doses of berberine treatment groups with a dose-dependent manner (P<0.01). The cell apoptosis was increased significantly in medium and high doses of berberine treatment groups dose-dependently (P<0.05). The protein levels of Bax were up-regulated, while those of Bcl-2 and p-P65 were down-regulated significantly by the treatment of berberine (P<0.05). In addition, the miRNA-146a levels were increased significantly in medium and high doses of berberine treatment groups (P<0.05) and showed a dose-dependent manner. The mRNA levels of Bax were decreased, while the mRNA levels of Bcl-2 were increased after transfection with miRNA-146a siRNA and co-incubated with berberine.CONCLUSION: Berberine promotes apoptosis of MCF-7 cells. The mechanism may be related to inhibit the activity of NF-κB by incresing the levels of miRNA-146a.     

Berberine promotes anti-proliferative effects of doxorubicin in T24 bladder cancer cells by enhancing apoptosis

AIM: To observe the effect of berberine (Ber) on doxorubicin (DOX)-induced apoptosis in bladder cancer T24 cells. METHODS: The cells were exposed to DOX in the presence or absence of different concentrations of Ber. The viability of the cells was determined by CCK-8 assay. The apoptosis was measured by Hoechst 33258 staining and the protein levels of cleaved caspase-3, cleaved caspase-9, Bcl-2 and Bax were detected by Western blotting.RESULTS: Ber enhanced the inhibitory effect of DOX on the viability of T24 cells and promoted DOX-induced apoptosis in T24 cells. DOX increased the protein levels of cleaved caspase-3, cleaved caspase-9 and Bax, all of which were enhanced by treatment with Ber. In contrast, Ber exposure further decreased the expression of Bcl-2 in DOX-treated T24 cells.CONCLUSION: Ber enhances the anti-proliferative effects of DOX through promoting apoptosis in bladder cancer cells.     

Effects of curcumin analogue T83 on apoptosis of homologous nasopharyngeal carcinoma cells with different radioresistance

AIM：To compare the effect of T83 (a 4-arylidene curcumin analogue) on the apoptosis of homologous nasopharyngeal carcinoma cells with different radioresistance. METHODS：The effects of T83 on the viability, apoptosis, mitochondrial membrane potential (MMP), expression of procaspase-3/procaspase-9/Cyt-C proteins and relative PTEN/Akt/p27 mRNA expression in CNE-2R cells and CNE-2 cells were detected and compared by the methods of MTT assay, Hoechst staining, flow cytometry, Western blotting and qRT-PCR. RESULTS：T83 inhibited the viability of CNE-2R cells with the IC50 of 0.9,0.4 and 0.2 μmol/L for 24 h, 48 h and 72 h,respectively, which was more effective than that inhibiting the viability of CNE-2 cells with the IC50 of 1.8,0.5 and 0.4 μmol/L, respectively. After treated with T83 for 48 h, chromatin condensation, margination and splitting into a massive structure were observed in CNE-2R cells and CNE-2 cells,and the late apoptotic rate of CNE-2R cells was increased from 1.57% to 27.26%, which was higher than that of CNE-2 cells (1.74% to 8.15%). After treated with T83 for 36 h, the MMP in CNE-2R cells decreased by 87.71% and that decreased by 50.47% in CNE-2 cells. After treated with T83 for 48 h, the protein levels of procaspase-3 and procaspase-9 were decreased, and the protein level of Cyt-C was increased, which were more susceptible in CNE-2R cells than those in CNE-2 cells. After treated with T83 for 24 h, the relative mRNA expression of PTEN and p27 was significantly up-regulated, and the mRNA expression of Akt was down-regulated, which were more susceptible in CNE-2R cells than those in CNE-2 cells. CONCLUSION：Compared with CNE-2 cells, the inhibitory effect of T83 on the viability of CNE-2R cells is more specific by starting the mitochondrial apoptotic pathway, which is due to the inhibition of PTEN/Akt/p27 signaling pathway.     

Effects of phycocyanin on apoptosis of human laryngeal cancer HEP-2 cells

AIM: To investigate the effect of phycocyanin on the apoptosis of human laryngeal cancer HEP-2 cells and to explore the inhibitory mechanism of phycocyanin to tumor. METHODS: Highly purified phycocyanin was extracted from spirulina. The effects of phycocyanin at different concentrations on the growth of human laryngeal cancer HEP-2 cells were detected by MTT assay. In addition, the cell structures were observed under electron microscope. The cell apoptosis was analyzed by flow cytometry. The production of reactive oxygen species (ROS) was measured by flow cytometry. Enzymatic activities of caspase-3, -8 and -9 were measured by chemical colorimatry. The expression of Bax, Bcl-2, Fas, P53, caspase-3 and caspase-9 at mRNA and protein levels was determined by RT-PCR and Western blot. RESULTS: MTT test confirmed that phycocyanin inhibited the cell activity of HEP-2 cells with time and dose dependent manners. The result of electron microscope observation and flow cytometry indicated that phycocyanin induced the apoptosis of HEP-2 cells. The intracellular content of ROS was increased. The activities of caspase-3, -8 and -9 were increased. RT-PCR showed that the mRNA expression of Bax, Fas, P53, caspase-3, caspase-9 was increased and Bcl-2 was decreased. The results of Western blot were consistent with the results of RT-PCR. CONCLUSION: Phycocyanin might induce apoptosis of HEP-2 cells by down-regulating Bcl-2, up-regulating Bax, Fas and P53, and the transduction of apoptotic signals in the human laryngeal cancer cells.     

Pin1 inhibitor juglone induces apoptosis in human cervical cancer SiHa cells

AIM: To explore the effect of peptidyl-prolyl cis/trans isomerase (Pin1) inhibitor juglone on apoptosis of human cervical cancer SiHa cells. METHODS: Cultured SiHa cells were incubated with juglone at concentrations of 10, 20, 50, 80 and 100 μmol/L for 24 h. The SiHa cell activity was detected by methyl thiazolyl tetrazolium (MTT) assay. The cell apoptosis was analyzed by flow cytometry with Hoechst 33258 staining. The protein levels of cleaved caspase-3,8,9 and PTEN was determined by Western blotting. RESULTS: In different doses of juglone groups, the SiHa cell growth was greatly inhibited (P<0.05) in a dose-dependent manner as compared with control group. The IC₅₀ of juglone was 20.4 μmol/L. After treatment with juglone at concentration of 20 μmol/L for 12 h, the apoptosis of SiHa cells was induced, and the typical morphological changes of cell apoptosis such as karyopyknotic pyknic hyperfluorescence bolus, nuclear fragmentation and apoptotic body were observed by Hoechst 33258 staining. The early apoptotic rate was increased significantly as compared with the control. The protein levels of cleaved caspase-3, 8, 9 and PTEN were also increased significantly as compared with control group. CONCLUSION: Juglone significantly inhibits the cell activity and induces the apoptosis of SiHa cells in vitro by inhibiting the caspase pathway and increasing the expression of anti-oncogene.     

MicroRNA-146a promotes apoptosis of gastric cancer SGC-7901 cells by targeting TAK1

AIM: To explore the effect of microRNA-146a (miR-146a) on apoptosis of human gastric cancer SGC-7901 cells and the underluing mechanism. METHODS: miR-146a mimic (up-regulated miR-146a expression) and miR-146a inhibitor (down-regulated miR-146a expression) were transfected into the SGC-7901 cells by liposome method. At the same time, miRNA nonsense sequence transfection group as the negative control group (NC group) was set up. RT-qPCR was used to evaluate the levels of miR-146a in the SGC-7901 cells after transfection. The effects of miR-146a on the cell apoptosis and growth were assessed by flow cytometry analysis and CCK-8 assay, respectively. The effect of over-expression or knockdown of miR-146a on transforming growth factor-β-activated kinase 1 (TAK1)/nuclear factor-kappa B (NF-κB) signaling was evaluated by RT-qPCR and Western blot. RESULTS: miR-146a modulated apoptosis of SGC-7901 cells. Over-expression of miR-146a significantly increased apoptosis, whereas knockdown of miR-146a inhibited the apoptosis of SGC-7901 cells. The expression of TAK1 at mRNA and protein levels was significantly decreased when miR-146a mimic was transfected into the SGC-7901 cells (P<0.05). On the contrast, the expression of TAK1 at mRNA and protein were significantly higher in miR-146a inhibitor transfection group than that in NC group (P<0.05), suggesting that miR-146a negatively regulated TAK1 expression. Moreover, knockdown of TAK1 enhanced the apoptosis of SGC-7901 cells (P<0.01), while over-expression of TAK1 inhibited the apoptosis of SGC-7901 cells(P<0.01). Additionally, both over-expression of miR-146a and knockdown of TAK1 led to a prominent increase in the expression of NF-κB inhibitor protein alpha (IκBα) and a significat decrease in B cell lymphoma-2 (Bcl-2) level in the SGC-7901 cells. CONCLUSION: miR-146a significantly promotes apoptosis of SGC-7901 cells by inhibition of NF-κB pathway via targeting TAK1.     

Autophagy promotes survival of adipose cells by inhibiting apoptosis under in vitro starvation

AIM: To detect the changes of autophagy in adipose cells under starvation, and to clarify the effects of autophagy on the cell survival and apoptosis under starvation. METHODS: Rapamycin (RAP) was applied to promote autophagy of adipose cells. These cells were then incubated under oxygen-glucose deprivation (OGD) condition. After exposure of the cells to OGD, the changes of autophagy and apoptosis were determined by Western blotting, transmission electron microscopy and TUNEL assay. RESULTS: Compared with the control cells, OGD-challenged cells had much higher level of autophagy. The apoptotic rate in OGD group was much higher than that in control group, which was reflected by increased protein level of activated caspase-3 and percentages of TUNEL positive cells. Preconditioning with RAP effectively improved OGD-induced autophagy, but did not affect the cell survival and apoptosis under normal condition, and obviously decreased the apoptotic rate of the cells under OGD condition. CONCLUSION: Autophagy protects adipose cells against starvation-induced apoptosis. Promotion of autophagy is helpful for attenuating starvation-induced apoptosis of the cells under OGD condition.     

Effects of shRNA-mediated hWAPL silencing on proliferation and apoptosis of human cervical cancer CaSki cells

AIM：To investigate the role of human wings apart-like (hWAPL) protein in proliferation and apoptosis of human cervical cancer CaSki cells through hWAPL gene silencing by specific short hairpin RNA (shRNA) duplexes. METHODS：The relative hWAPL mRNA and protein expression levels were detected by real-time fluorescence quantitative PCR and Western blotting, respectively. Cell proliferation was detected by MTT assay, and the apoptosis was determined by Annexin V-PE and Hoechst 33258 staining. Western blotting was used to analyze the expression of cleaved caspase-3, p21 and p27. The effect of hWAPL gene silencing on the in vivo tumorigenic capacity of CaSki cells was investigated in a tumor-bearing nude mouse model. RESULTS：Real-time fluorescence quantitative PCR and Western blotting showed that hWAPL mRNA and protein expression in CaSki cells was efficiently inhibited by hWAPL shRNA. The shRNA-mediated hWAPL silencing inhibited the proliferation and induced the apoptosis of CaSki cells. Additionally, the expression levels of cleaved caspase-3, p21 and p27 were up-regulated in hWAPL knockdown cells. Knockdown of hWAPL also inhibited the in vivo tumorigenic capacity of CaSki cells. CONCLUSION：hWAPL is involved in the regulation of the proliferation and apoptosis of CaSki cells in vitro and in vivo, and might serve as a therapeutic target in cancer treatment.     

Hypoxia promotes apoptosis of neural stem cells and down-regulates miR-26a

AIM: To investigate the effect of cobalt chloride (CoCl₂) on the apoptosis of neural stem cells (NSCs) and the expression of microRNA-26a (miR-26a) in vitro, and to explore the mechanisms of NSC apoptosis induced by CoCl₂. METHODS: NSCs were exposed to CoCl₂ at different doses (200~600 μmol/L) for 24 h. The cell viability and apoptosis were measured by CCK-8 assay and TUNEL method. The expression of miR-26a-3p, miR-26a-5p, GSK-3β, caspase-3, Bcl-2 and Bax was examined by real-time PCR. The protein levels of Bcl-2 and Bax were detected by Western blotting. RESULTS: The cell viability was inhibited and the apoptosis of NSCs was increased significantly by CoCl₂ in a dose-dependent manner (P<0.05). CoCl₂ at concentration of 400 μmol/L for 24 h was used to induce apoptosis and the expression of miR-26a was down-regulated compared with control (P<0.05). Exposure to CoCl₂ at concentration of 400 μmol/L up-regulated the expression of GSK-3β, caspase-3 and Bax, down-regulated the expression of Bcl-2 and Bcl-2/Bax (P<0.05). CONCLUSION: CoCl₂ at concentration of 400 μmol/L induces the apoptosis of NSCs obviously. CoCl₂ may induce the NSC apoptosis by mitochondrial apoptotic pathway. Declining miR-26a may be related to NSC apoptosis.     

Stat5b signaling pathway regulates the expression of Survivin and promotes apoptosis in human colon cancer cells

AIM: The purpose of the study was to examine colon cancer cell lines to determine whether Stat5b/Survivin plays an important role in the process of apoptosis in colon cancer cells. METHODS: Protein lysates were extracted from colon cancer cells. Human colon cancer cell line HT29 was transfected with Stat5b antisense oligonucleotide mediated by liposome. MTT assay was used to measure the proliferation. Flow cytometry was applied to analyze the cell cycle and apoptosis. EMSA was used to detect the activity of Stat5. Western blotting was applied to measure the expression of Stat5, p-Stat5, cyclin D1, Survivin, Bcl-2 and Bcl-x L. RESULTS: Targeting of Stat5 using antisense oligonucleotide against the translation site resulted in apoptosis and downregulaed the expressions of Stat5, p-Stat5, cyclin D1 and Survivin, but not Bcl-2 and Bcl-xL. CONCLUSION: Constitutive activation of Stat5 is associated with the carcinogenesis of colon cancer cells. Blocking of Stat5 signaling inhibits the expression of Survivin and induces apoptosis in colon cancer cells.     

Effects of HuR on cell viability,migration and invasion of gastric cancer cell line MGC-803

AIM:To investigate the effects of HuR on cell function of gastric cancer cell line MGC-803. METHODS:The mRNA expression level of HuR was detected by RT-qPCR in the tumor samples of 80 gastric cancer patients diagnosed clinically. HuR gene knock-down was achieved by transfection of si-HuR into the MGC-803 cells. The invasion, migration and viability of MGC-803 cells were measured by the scratch wound hearing, Transwell and CCK-8 assays, respectively. RESULTS:High mRNA expression of HuR was observed in 67 cases (84%) of gastric cancer tissues as compared with their control samples. Furthermore, knock-down of HuR expression effectively inhibited the invasion, migration and viability of the MGC-803 cells (P<0.05), indicating that HuR play an important role in gastric cancer as an oncogene. CONCLUSION:Abnormal expression of HuR is correlated with the progression of gastric cancer. Knock-down of HuR expression inhibits the invasion, migration and viability of MGC-803 cells.     

Survivin-2B induces apoptosis of human breast cancer cells

AIM：To explore the role of survivin-2B in the process of tumor cell apoptosis. METHODS：The survivin-2B gene was cloned into pcDNA3.1 vector and the recombinant plasmid pcDNA3.1-survivin-2B was obtained. Human breast cancer MCF7 cells were transfected with pcDNA3.1 and pcDNA3.1-survivin-2B using Lipofectamine 2000. The cell cycle was determined by propidium iodide staining, and the apoptosis was detected by annexin V/7-AAD staining 48 h after transfection. Meanwhile, tatal RNA was extrated and multiplex polymerase chain reaction based on GenomeLab GeXP Genetic Analysis System was performed to detect the expression of 21 tumor-related genes. RESULTS：Flow cytometry analysis indicated that over-expression of survivin-2B promoted the apoptosis and cell cycle arrest of MCF7 cells. Compared with control group, totally 10 differential expressed genes were related to the over-expressed survivin-2B, among which 2 were up-regulated and 8 were down-regulated. The expression of aldehyde dehydrogenase 4 family member A1 (ALDH4A1) was 48% down-regulated, and the expression of protein regulator of cytokinesis 1 (PRC1) was 1.08 folds up-regulated. CONCLUSION：Survivin-2B induces the expression changes of some tumor-related genes, which results in the apoptosis and G2/M arrest of MCF7 cells.     

Effect of sulodexide on apoptosis of human dermal microvascular endothelial cells exposed to hypoxia

AIM: To investigate the effect of sulodexide (SDX) on the apoptosis of human dermal microvascular endothelial cells (HDMECs) exposed to hypoxia and its underlying mechanism. METHODS: The HDMECs were cultured and divided into normoxia control group cultured under normoxic condition; hypoxia control group cultured in a humid incubator maintained at 37℃ with 5% CO₂ and 1% O₂ for 24 h; treatment groups treated with SDX at 0.25, 0.5 and 1 LSU/mL for 24 h under hypoxic condition. The cell viability was measured by CCK-8 assay. The apoptotic rate of the HDMECs was analyzed by flow cytometry. The activity of caspase-3 in HDMECs was examined by caspase-3 activity assay kit. The expression of pro-apoptotic factor P53, caspase-3, Bax and anti-apoptotic factor Bcl-2 at mRNA and protein levels was determined by real-time PCR and Western blot. RESULTS: SDX increased the viability of HDMECs exposed to hypoxia, but also decreased the apoptosis. Furthermore, SDX down-regulated the expression of pro-apoptotic factor P53, Bax and caspase-3 at mRNA and protein levels as well as the activity of caspase-3, while the expression of anti-apoptotic factor Bcl-2 was up-regulated. CONCLUSION: SDX significantly increases the viability and decreases the apoptosis of HDMECs exposed to hypoxia. Inhibition of the mitochondrial apoptosis pathway may be involved in the underlying mechanism.