OBJECTIVETo observe the effect of anti-survivin oligonucleotides (ASODN) on the invasion and growth of peritoneally implanted ovarian cancer cell xenografts in nude mice.

METHODSNude mouse models bearing peritoneally implanted ovarian cancer cell (SKOV3) xenografts were established and subjected to intraperitoneal injection of survivin ASODN or saline (control). The number and weight of the intraperitoneal xenografts were compared between the two groups.The expressions of interleukin (IL-6), signal transducer and activator of transcription3 (STAT3), phosphorylated STAT3 (p-STAT3), and survivin protein in the tumor tissues were detected with Western blotting in both groups.

RESULTSCompared with those in the control group, the number and weight of the intraperitoneal xenografts were significantly reduced in ASODN group (P<0.05). ASODN treatment also resulted in significantly lowered protein levels of IL-6, STAT3, p-STAT3, and survivin in the tumor tissues (P<0.05).

CONCLUSIONSurvivin ASODN can suppress the invasion and migration capacity of ovarian cancer cells and inhibit peritoneal metastasis of the tumor in nude mice possibly though down-regulation of IL-6/STAT3 signaling pathway.

Animals ; Cell Line, Tumor ; Down-Regulation ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; antagonists & inhibitors ; metabolism ; Interleukin-6 ; metabolism ; Mice ; Mice, Nude ; Neoplasm Transplantation ; Oligonucleotides ; pharmacology ; Ovarian Neoplasms ; pathology ; therapy ; STAT3 Transcription Factor ; metabolism

OBJECTIVETo investigate the effect of small interfering RNA (siRNA) silencing Apollon gene combined with tetramethylpyrazine (TMP) on the proliferation and apoptosis of human chronic myeloid leukemia cell line K562.

METHODSK562 cells were divided into blank control, negative control, and RNA interference (RNAi) group. For the RNAi group, the pGPHI-GFP-Neo-Apollon eukaryotic expression vector based on the best Apollon siRNA fragments screened out in previous experiments was constructed; the blank control group received no treatment, and the negative control group was transfected with negative plasmid vector. The mRNA and protein expression of Apollon was measured by RT-PCR and cell immunofluorescence, respectively. Additionally, TMP (320 μg/mL) was applied to set TMP, TMP+negative control, and TMP+RNAi groups. The cell viability and apoptosis rate were determined by MTT assay and flow cytometry, respectively.

RESULTSThe constructed vector was stably expressed in K562 cells. The RNAi group had significantly lower mRNA and protein expression of Apollon than the blank control group and negative control (P<0.05). The RNAi group had significantly increased proliferation inhibition rate and apoptosis rate, as compared with the blank contorl group (P<0.05). The TMP+RNAi group had significantly increased proliferation inhibition rate and apoptosis rate, as compared with the RNAi, and TMP groups (P<0.05).

CONCLUSIONSApollon siRNA can significantly inhibit the proliferation and promote the apoptosis of K562 cells, and the addition of TMP can further increase the proliferation inhibition rate and apoptosis rate, suggesting that siRNA technology combined with drugs has a significant potential value in the treatment of leukemia.

Apoptosis ; Cell Proliferation ; Flow Cytometry ; Humans ; Inhibitor of Apoptosis Proteins ; antagonists & inhibitors ; genetics ; K562 Cells ; Pyrazines ; pharmacology ; RNA, Small Interfering ; genetics

The mitochondria-mediated caspase activation pathway is a major apoptotic pathway characterized by mitochondrial outer membrane permeabilization (MOMP) and subsequent release of cytochrome c into the cytoplasm to activate caspases. MOMP is regulated by the Bcl-2 family of proteins. This pathway plays important roles not only in normal development, maintenance of tissue homeostasis and the regulation of immune system, but also in human diseases such as immune disorders, neurodegeneration and cancer. In the past decades the molecular basis of this pathway and the regulatory mechanism have been comprehensively studied, yet a great deal of new evidence indicates that cytochrome c release from mitochondria does not always lead to irreversible cell death, and that caspase activation can also have non-death functions. Thus, many unsolved questions and new challenges are still remaining. Furthermore, the dysfunction of this pathway involved in cancer development is obvious, and targeting the pathway as a therapeutic strategy has been extensively explored, but the efficacy of the targeted therapies is still under development. In this review we will discuss the mitochondria-mediated apoptosis pathway and its physiological roles and therapeutic implications.
Animals ; Antineoplastic Agents ; pharmacology ; therapeutic use ; Apoptosis ; drug effects ; Caspases ; metabolism ; Cytochromes c ; metabolism ; Humans ; Inhibitor of Apoptosis Proteins ; antagonists & inhibitors ; metabolism ; Membrane Potential, Mitochondrial ; drug effects ; Mitochondria ; drug effects ; metabolism ; Neoplasms ; drug therapy ; metabolism ; pathology ; Proto-Oncogene Proteins c-bcl-2 ; metabolism

OBJECTIVETo investigate the effect of PDTC (inhibitor of NF-κb) on apoptosis of human gastric cancer cell line SGC-7901 induced by tumor necrosis factor α (TNF-α) and explore the related mechanisms.

METHODSAfter the treatment with different concentrations of PDTC, TNF-α or PDTC combined with TNF-α on gastric cancer cell line SGC-7901, the growth inhibition of SGC-7901 was measured by MTT assay. Hoechst was used to assess SGC-7901 cell apoptosis. The protein expressions of survivin and caspase-3 were detected by Western blot assay.

RESULTSThe growth inhibition rate of SGC-7901 induced by PDTC (15, 30, 60, 100 μmol/L) was (12.14±0.91)%, (20.00±1.11)%, (37.63±1.01)% and (41.46±1.07)%. Different concentrations of PDTC all inhibited the growth of SGC-7901 significantly (all P<0.01), The growth inhibition rate of SGC-7901 induced by 25 mg/L TNF-α was (2.38±0.67)%, which could not significantly inhibit the growth of SGC-7901 [control (1.50±0.81)%], while TNF-α of 50, 100, 150 mg/L could inhibit the growth of SGC-7901 significantly [(4.53±0.85)%, (4.43±0.70)% and (4.74±1.07)%, all P<0.05]. PDTC (15 μmol/L) combined with TNF-α (25, 50, 100, 150 mg/L) significantly increased the cell growth inhibition rate compared with TNF-α alone or PDTC 15 μmol/L alone (all P<0.01). Hoechst assay showed that 100 mg/L TNF-α, 15 μmol/L PDTC and combination of above two all induced cell apoptosis (P<0.01), and the combination group had significantly higher percentage of cell apoptosis (P<0.01). Survivin protein was significantly down-regulated in combination group as compared with single TNF-α (100 mg/L) group, but was not significant down-regulated as compared with single PDTC (15 μmol/L) group. Caspase-3 protein expression was significantly increased in combination group as compared with other two groups.

CONCLUSIONPDTC can enhance the cell apoptosis induced by TNF-α, which may be associated with the blocking of TNF-α-activated NF-κB signaling pathway by PDTC, the down-regulation of survivin expression, and up-regulation of caspase-3 expression.

Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Gene Expression Regulation, Neoplastic ; Humans ; Inhibitor of Apoptosis Proteins ; metabolism ; NF-kappa B ; antagonists & inhibitors ; Proline ; analogs & derivatives ; pharmacology ; Signal Transduction ; Stomach Neoplasms ; metabolism ; pathology ; Thiocarbamates ; pharmacology ; Tumor Necrosis Factor-alpha ; pharmacology

Paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride; PQ), an effective and widely used herbicide, was commercially introduced in 1962. It is reduced by the electron donor NADPH, and then reduced PQ transfers the electrons to molecular oxygen, resulting in the production of reactive oxygen species (ROS), which are related to cellular toxicity. However, the influence of continuous hypoxia on PQ-induced ROS production has not fully been investigated. We evaluated in vitro the protective effect of continuous hypoxia on PQ-induced cytotoxicity in the human carcinogenic alveolar basal epithelial cell line (A549 cells) by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and live and dead assay, and by measuring lactate dehydrogenase (LDH) release. To elucidate the mechanism underlying this effect, we monitored the immunofluorescence of intracellular ROS and measured malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities. Continuous hypoxia protected the A549 cells from PQ-induced cytotoxicity. Continuous hypoxia for a period of 24 h significantly reduced intracellular ROS, decreased MDA concentration in the supernatant, and normalized SOD and GPx activities. Continuous hypoxia attenuated PQ-induced cell toxicity in A549 cells. This protective effect might be attributable to the suppression of PQ-induced ROS generation.
Apoptosis/drug effects ; Cell Line, Tumor ; Cell Proliferation/drug effects ; Flavonoids/pharmacology ; *Gene Expression Regulation, Neoplastic ; Hepatocyte Growth Factor/*pharmacology ; Humans ; Inhibitor of Apoptosis Proteins/antagonists & inhibitors/*genetics ; MAP Kinase Kinase Kinases/antagonists & inhibitors ; Neoplasm Invasiveness ; Promoter Regions, Genetic ; Protein Binding ; Proto-Oncogene Proteins c-jun/genetics/*metabolism ; Stomach Neoplasms/genetics/*metabolism/pathology ; Urokinase-Type Plasminogen Activator/*genetics

BACKGROUNDSurvivin, a member of the inhibitor of apoptosis protein (IAP) family, overexpresses in tumor cells and not expresses in terminally differentiated adult tissues. This study aimed to investigate the effects of survivin-specific siRNA on cell proliferation, apoptosis and chemosensitivity to cisplatin in vitro and in vivo and explore the mechanisms about decreasing expression of survivin in reversing cancer cells resistance to chemotherapeutic drug.

METHODSSurvivin-specific siRNA was transfected into A549/DDP cells. The expression of survivin and lung resistance-related protein (LRP) mRNA levels were determined by RT-PCR, chemosensitivity of A549/DDP (cisplatin) cells to cisplatin was determined by MTT assay, and apoptosis and cell cycle were determined by flow cytometry (FCM). The protein expression levels of survivin, LRP, cyclin-D(1), caspase-3 and bcl-2 were determined by Western blotting analyses. The effect of survivin siRNA inhibition on tumor growth was studied in athymic nude mice in vivo.

RESULTSSurvivin-specific siRNA efficiently down-regulated survivin expression. The cell cycle was arrested at G2/M phase, and apoptosis was obviously found. Inhibition of survivin expression could make the IC50 and drug-resistant index of cisplatin decrease, and enhance the cancer cells sensitivity to cisplatin. After transfection by survivin-specific siRNA, expression of LRP and cyclin-D1 were downregulated, caspase-3 expression was upregulated, bcl-2 expression had no obvious change. The animal experiment confirmed knockdown of survivin could inhibit the tumor growth.

CONCLUSIONSSurvivin-specific siRNA can efficiently suppress the expression of survivin, increase apoptosis, inhibit cells proliferation and enhance the chemosensitivity to cisplatin in vitro and in vivo. Suppression of survivin expression helping to reverse drug-resistance may have relationship with downregulation of LRP and upregulation of caspase-3. Anti-tumor strategies based on the inhibition of survivin may be useful in targeting lung adenocarcinomas.

Adenocarcinoma ; drug therapy ; pathology ; Animals ; Apoptosis ; Caspase 3 ; analysis ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Cyclin D1 ; analysis ; Drug Resistance, Neoplasm ; Female ; Humans ; Inhibitor of Apoptosis Proteins ; Lung Neoplasms ; drug therapy ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; Microtubule-Associated Proteins ; antagonists & inhibitors ; genetics ; Proto-Oncogene Proteins c-bcl-2 ; analysis ; RNA, Messenger ; analysis ; RNA, Small Interfering ; genetics ; Vault Ribonucleoprotein Particles ; genetics

OBJECTIVEThe aim of this study was to investigate the changes in mTOR activity and survivin expression in liver cancer cell line HepG2 cells treated with tamoxifen.

METHODSSurvivin transcription level and p70S6K was demonstrated by PCR, dual-luciferase reporter assay and Western blot analysis, respectively, and the apoptosis in the HepG2 cells was detected by flow cytometry.

RESULTSTamoxifen leads to apoptosis of the cells and reduction in survivin expression, as well as a dramatic reduction in the activated form of p70S6K. Treating HepG2 cells with rapamycin, a specific mTOR inhibitor, significantly reduced the survivin protein level but not affected the survivin transcription, indicating that tamoxifen and rapamycin were synergistic in regards to down-regulation of survivin expression in hepatocellular carcinoma cells.

CONCLUSIONSOur results suggest that tamoxifen down-regulates survivin expression in HepG2 cells and it is mediated by transcriptional and post-transcriptional level via PI3K/Akt/mTOR pathway to induce apoptosis.

Antibiotics, Antineoplastic ; pharmacology ; Antineoplastic Agents, Hormonal ; pharmacology ; Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; Down-Regulation ; Drug Synergism ; Hep G2 Cells ; Humans ; Inhibitor of Apoptosis Proteins ; genetics ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; RNA, Messenger ; metabolism ; Ribosomal Protein S6 Kinases, 70-kDa ; metabolism ; Signal Transduction ; Sirolimus ; pharmacology ; TOR Serine-Threonine Kinases ; antagonists & inhibitors ; metabolism ; Tamoxifen ; pharmacology

OBJECTIVETo determine the expression level changes of survivin, a inhibitor of apoptosis protein, followed by activation of insulin receptors in human hepatocellular carcinoma HepG2 cell line, and to investigate the signalling pathway involved in the regulation.

METHODSHuman hepatocellular carcinoma HepG2 cells were treated with insulin alone or pre-treated with LY294002, a specific inhibitor of PI3K signalling pathway, to determine whether blocking PI3K signaling can attenuate the up-regulation of survivin expression. Real time RT-PCR and Western blot analysis were used to measure survivin mRNA and protein changes before and after treatment, respectively.

RESULTSWithout serum supplement, HepG2 cells expressed a small amount of survivin. Insulin induced survivin expression in a dose- and time-dependent fashion. Survivin expression was blocked if cells were pre-treated with LY294002 prior to insulin stimulation.

CONCLUSIONInsulin induces survivin expression via PI3K signalling pathway, suggesting that to interfere the key gene in this signalling pathway may block survivin expression, therefore, promoting apoptosis in hepatocellular carcinoma cells.

Apoptosis ; Chromones ; pharmacology ; Dose-Response Relationship, Drug ; Gene Expression Regulation, Neoplastic ; Hep G2 Cells ; Humans ; Inhibitor of Apoptosis Proteins ; Insulin ; administration & dosage ; pharmacology ; Microtubule-Associated Proteins ; genetics ; metabolism ; Morpholines ; pharmacology ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; RNA, Messenger ; metabolism ; Signal Transduction ; Up-Regulation

Apoptosis ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chromones ; pharmacology ; Cyclin-Dependent Kinase Inhibitor p27 ; antagonists & inhibitors ; physiology ; Endometrial Neoplasms ; drug therapy ; pathology ; Estradiol ; pharmacology ; Female ; G1 Phase ; drug effects ; Humans ; Intracellular Signaling Peptides and Proteins ; antagonists & inhibitors ; physiology ; Morpholines ; pharmacology ; Phosphatidylinositol 3-Kinases ; antagonists & inhibitors ; physiology ; Proto-Oncogene Proteins c-akt ; antagonists & inhibitors ; physiology ; Signal Transduction ; drug effects ; physiology

OBJECTIVETo investigate the effects of survivin antisense oligonucleotide (ODN) on cell proliferation and apoptosis of HL-60 cells.

METHODSSynthetic ODN was completely phosphorothioate-modified. Cationic lipid-mediated antisense ODN was transferred into HL-60 cells. The expression of survivin mRNA and protein was detected by RT-PCR and Western Blot. The incorporation of MTT was used as the measurement of HL-60 proliferation. The cell-cycle and apoptosis were analyzed by flow cytometry.

RESULTSHL-60 cells spontaneously expressed survivin mRNA and protein. Both mRNA and protein expression of survivin decreased significantly in the antisense ODN transfected cells in comparison to that in the original cells and cells transfected with sense ODN. Survivin antisense ODN significantly inhibited cell proliferation and induced apoptosis in a dose-dependent manner. The cell-cycle in the antisense ODN-transfected cells stopped at the G2/M phase.

CONCLUSIONSAntisense ODN targeting at survivin mRNA can inhibit HL-60 cell proliferation and induce G2/M stop and apoptosis.

Apoptosis ; drug effects ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; HL-60 Cells ; drug effects ; Humans ; Inhibitor of Apoptosis Proteins ; Microtubule-Associated Proteins ; antagonists & inhibitors ; genetics ; Neoplasm Proteins ; antagonists & inhibitors ; genetics ; Oligonucleotides, Antisense ; pharmacology ; RNA, Messenger ; analysis