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Telmisartan, one unique angiotensin II type 1 receptor blocker, has been attracting attention due to its putative peroxisome proliferator-activated receptor (PPAR)-γ or β/δ actions. Recently, telmisartan has been reported to exert neuroprotective effects in animal models of Parkinson's disease (PD). However, the underlying mechanisms have not been fully clarified. Recently, accumulating evidence has shown that endoplasmic reticulum (ER) stress plays a crucial role in rotenone-induced neuronal apoptosis. Additionally, studies have revealed that inositol-requiring enzyme/endonuclease 1α (IRE1α) is necessary and sufficient to trigger ER stress. In the present study, we aimed to determine whether ER stress-activated IRE1α-mediated apoptotic pathway is involved in the neuroprotection of telmisartan in the rotenone rats of PD and explore the possible involvement of PPAR-β/δ activation. The catalepsy tests were performed to test the catalepsy symptom. The dopamine content and α-synuclein expression were ascertained through high-performance liquid chromatography and immunohistochemistry, respectively. The expression of IRE1α, TNF receptor associated factor 2 (TRAF2), caspase-12 and PPAR-β/δ was detected by western blot. Neuronal apoptosis was assessed by TUNEL and immunohistochemistry. Our results show that telmisartan ameliorated the catalepsy symptom and attenuated dopamine depletion as well as α-synuclein accumulation. Moreover, telmisartan decreased ER stress-mediated neuronal apoptosis. Furthermore, telmisartan inhibited IRE1α-TRAF2-caspase-12 apoptotic signaling pathway. Additionally, telmisartan activated PPAR β/δ, implying that PPAR-β/δ activation properties of telmisartan are possibly or partially involved in the neuroprotective effects. In conclusion, our findings suggest that suppressing ER stress-activated IRE1α-TRAF2-caspase-12 apoptotic pathway is involved in the neuroprotective effects of telmisartan in the rotenone rats of PD., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A major problem in patients with multiple myeloma is chemotherapy resistance, which develops in myeloma cells upon interaction with bone marrow stromal cells. However, few studies have determined the role of bone marrow adipocytes, a major component of stromal cells in the bone marrow, in myeloma chemotherapy resistance. We reveal that mature human adipocytes activate autophagy and upregulate the expression of autophagic proteins, thereby suppressing chemotherapy-induced caspase cleavage and apoptosis in myeloma cells. We found that adipocytes secreted known and novel adipokines, such as leptin and adipsin. The addition of these adipokines enhanced the expression of autophagic proteins and reduced apoptosis in myeloma cells. In vivo studies further demonstrated the importance of bone marrow-derived adipocytes in the reduced response of myeloma cells to chemotherapy. Our findings suggest that adipocytes, adipocyte-secreted adipokines, and adipocyte-activated autophagy are novel targets for combatting chemotherapy resistance and enhancing treatment efficacy in myeloma patients.

Adipose tissue is an important energy reservoir, and its over-development results in obesity in humans or body fat over-deposition in livestock. Loss of preadipocytes through apoptosis has been proposed as an alternative way to reduce adipose tissue mass. At present, the effect and regulatory mechanism of Sirt1 and camptothecin on porcine preadipocyte apoptosis are still largely unknown. Here, we evaluated whether Sirt1 had any role in the basal cellular and camptothecin-induced conditions in porcine preadipocytes. Flow cytometric analysis shows that viable cells decrease as well as early apoptotic and late apoptotic cells increase after knockdown of Sirt1 in porcine preadipocytes. Camptothecin induces porcine preadipocyte apoptosis in a dose-dependent manner, assessed with the Hoechst staining and western blot analysis. Interestingly, silencing of Sirt1 significantly enhances sensitivity of porcine preadipocytes to camptothecin, which may be due to upregulation of p53, acetylated p53, Bax, cleaved caspase-3 and downregulation of Bcl-2. On the contrary, under the Sirt1 overexpression condition viable cells' number significantly increases when challenging with camptothecin, and the protein levels of cleaved caspase-3, p53, acetylated p53 and Bax are downregulated. We also find that hyperacetylated p53 is the major effect of Sirt1 knockdown by overexpression of a mutated p53, whereas Sirt1 overexpression prevents camptothecin-induced apoptosis through p53 deacetylation in preadipocytes. Furthermore, repressing preadipocyte apoptosis of Sirt1 is mediated by direct interaction with cleaved caspase-3 using immunoprecipitation and inhibition of caspase-3 transcriptional activity using luciferase reporter assays., (Copyright © 2013 Elsevier Inc. All rights reserved.)

The aim of this study is to examine the effect and mechanism of a selective cyclooxygenase-2 (COX-2) inhibitor NS-398 on inducing apoptosis of esophageal cancer cells. After the treatment with NS-398 on esophageal carcinoma EC9706 cell, MTT assay was used to observe the inhibition of EC9706 cell growth and apoptosis was determined by electronic microscopy and flow cytometry. The expression of survivin and caspase-3 was examined using immunocytochemical technique. The dose of 0.01–0.1 mM NS398 showed the inhibitory effect on growth of EC9706 cell lines and induce apoptosis in a dose- and time-effective manner; moreover, NS-398 also downregulated the level of expression of survivin and elevated the expression of capase-3. NS-398 can induce apoptosis of the esophageal carcinoma EC9706 cells by means of adjusting expression of survivin and caspase-3.

The magnetic responsibility and antitumor effect of magnetic gemcitabine stealth nano-liposomes (MGSL) on breast cancer cell line MCF-7 in vitro and in vivo was evaluated. The magnetic response and targeting effect of MGSL in vivo were investigated. Morphological feature and ultrastructure changes of apoptosis of MCF-7 cells were observed. The effect of MGSL on proliferation inhibitory rate of MCF-7 cells was measured with MTT method. The FCM analysis was carried out to examine the cell cycle distribution and cell apoptotic rate. The antitumor effect on human breast cancer xenografts in nude mice was also studied. MGSL was able to converge at the targeting tissue under tridimensional magnetic field and the gemcitabine concentration around it increased, while the amount of gemcitabine in other organs decreased, such as in kidneys and heart. MCF-7 cell line was sensitive to MGSL and the cytotoxity was correlated with the loaded drug dose. The effect of MGSL on apoptosis of MCF-7 was obvious and the rate of apoptosis was 51.62%. The growth speed of tumor in the group of MGSL (+) significantly slowed down than that of other groups. MGSL prepared by reverse-phase evaporation method met with the demand of targeted delivery system, and it might be an effective antitumor agent.

Ubiquitin-proteasome pathway (UPP) is the major system for the selective degradation of cellular proteins that play key roles in cellular processes. Previous study indicated that ubiquitin-proteasome inhibitor MG-132 could inhibit growth of some carcinoma. However, anti-carcinoma mechanism of MG-132 is unclear. Our objective was to investigate mechanisms of growth inhibitory effect of MG-132 on gastric carcinoma cells. Gastric carcinoma cell SGC-7901 was treated with ubiquitin-proteasome inhibitor MG-132. Cell growth suppression was evaluated with 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. DNA synthesis was evaluated by (3)H-thymidine ((3)H-TdR) incorporation. Activity of telomerase was examined by telomeric repeat amplification protocol (TRAP) PCR-ELISA. Cell cycle and apoptosis were detected by flow cytometry (FCM). DNA fragment analysis was used to confirm the presence of apoptosis. Expression of p27kip1 and survivin was detected using the western blot method. After exposed to MG-132, the growth and value of (3)H-TdR incorporation of gastric carcinoma cells were obviously inhibited. TRAP PCR-ELISA showed that light absorption of cells gradually decreased after exposed to 5 microM of MG-132 for 24, 48, 72 and 96 h (P < 0.01). The percentage of cells at G(0)/G(1) phase was increased and that at S and G(2)/M phase was decreased (P < 0.01). The ratio of apoptotic cells treated with 5 microM MG-132 for 96 h was 53.7 +/- 6.4%. Agarose electrophoresis showed marked ladders. Moreover, expression of p27kip1 of cells was increased and expression of survivin was decreased. Our results suggest that MG-132 inhibits telomerase activity, induces apoptosis and G(1) arrest which is associated with upregulated p27kip1 expression and downregulated survivin expression in gastric carcinoma cells.

Recent evidence indicates that methyl jasmonate, a plant stress hormone, exhibits anticancer activity on human cancer cells. Whether methyl jasmonate could inhibit the growth of human neuroblastoma cells still, however, remains largely unknown. In this study, administration of methyl jasmonate to cultured neuroblastoma cell lines, SK-N-SH and BE(2)-C, resulted in a decrease of cell viability in a dose-dependent and time-dependent manner as demonstrated by MTT colorimetry and colony formation assay. The results from RT-PCR indicated that the expression of proliferating cell nuclear antigen, but not of cyclin D1, was downregulated by methyl jasmonate. Accordingly, the cell cycle of methyl jasmonate-treated neuroblastoma cells was arrested at the G0/G1 phase. Moreover, incubation of SK-N-SH and BE(2)-C cells with methyl jasmonate resulted in characteristic changes of apoptosis, as demonstrated by acridine orange-ethidium bromide (AO/EB) staining, Hoechst 33258 staining and flow cytometry. Moreover, methyl jasmonate decreased the expression of the X-linked inhibitor of apoptosis protein and survivin, critical members of the inhibitors of apoptosis protein family, in neuroblastoma cells. These findings indicate that methyl jasmonate suppresses the growth of cultured human neuroblastoma cells associated with downregulation of proliferating cell nuclear antigen, and induces apoptosis accompanied by downregulation of the X-linked inhibitor of apoptosis protein and survivin, which lays the groundwork for further investigation into the mechanisms of methyl jasmonate-mediated anticancer activities.

This study is to explore the inhibitory effect of methyl jasmonate on cell proliferation and expression of XIAP and survivin of human neuroblastoma cell line BE(2)-C. After cultivation of 1 - 2 mmol x L(-1) jasmonates with BE (2) -C cells for 6 - 24 h, the growth inhibiting rates of BE (2) -C cells were studied by MTT colorimetry. Cell proliferation was detected by colony formation assay. Cell cycle phases were assayed by propidium iodide staining flow cytometery. Cell apoptosis was inspected by acridine orange-ethidium bromide fluorescent staining, Hoechst 33258 fluorescent staining, and Annexin V-FITC and propidium iodide staining flow cytometry. Expressions of cyclin D1, XIAP and survivin were determined by RT-PCR and real-time RT-PCR. Methyl jasmonate inhibited the growth of BE(2)-C cells in a dose- and time-dependent manner. After addition of 1, 1.5 and 2 mmol x L(-1) of methyl jasmonate for 24 h, the inhibiting rates of cell growth reached 20.6% - 85.5% (P < 0.01), and the IC50 was 1.35 mmol x L(-1). The cell cycles were arrested at S phase. A part of cells presented the characteristic morphological changes of apoptosis. The early apoptotic rates were 13.51%, 17.32%, 24.59% (P < 0.01) and the cell death rates were 29.36% , 54.73% , 75.52% (P < 0.01), respectively. The expression of XIAP and survivin mRNA were downregulated by 18.5% - 68.9% , 22.4% - 48.7% (P < 0.05), respectively, without change in that of cyclin D1. The results indicated that methyl jasmonate could significantly inhibit the growth of BE(2) -C cells through inducing cell cycle arrest and apoptosis, downregulating the expression of XIAP and survivin might be one of its molecular mechanisms of action.

Aim: To characterize the molecular mechanisms of nitrofen-induced pulmonary hypoplasia., Methods: After administration of nitrofen to cultured type II A549 pneumocytes, cell proliferation and DNA synthesis were investigated by 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide colorimetry, colony formation assay, flow cytometry and [3H]-thymidine incorporation assay. Apoptosis was measured by terminal transferase-mediated dUTP nick-end-labeling, acridine orange-ethidium bromide staining and flow cytometry. Expression of proliferating cell nuclear antigen (PCNA) and apoptosis-related genes was assayed by immunofluorescence, RT-PCR and Western blot., Results: Nitrofen inhibited the cell proliferation of A549 cells in a dose- and time-dependent manner, accompanied by downregulation of PCNA. As a result, the DNA synthesis of nitrofentreated A549 cells decreased, while cell cycle was arrested at G0/G1 phase. Moreover, nitrofen induced apoptosis of A549 cells, which was not abolished by Z-Val-Ala- Asp(OCH3)- fluoromethylketone. In addition, nitrofen decreased the expression of Bcl-x( L), but not of Bcl-2, Bax, and Bak, resulting in a loss of mitochondrial membrane potential and the nuclear translocation of apoptosis-inducing factor (AIF). Meanwhile, nitrofen strongly activated the p38 mitogen-activated protein kinase (p38-MAPK). Pretreatment of cells with SB203580 (5 micromol/L) blocked nitrofen-induced phosphorylation of p38-MAPK and abolished nitrofen-induced AIF translocation and apoptosis in A549 cells., Conclusion: Nitrofen suppresses the proliferation of cultured type II pneumocytes accompanied by the downregulation of PCNA, and induces mitochondria-mediated apoptosis involving the activation of p38-MAPK.

Objective: To explore the growth inhibition effects and apoptosis inducing mechanisms of curcumin on human ovarian cancer cell line A2780., Methods: After treatment with 10 - 50 micromol/L curcumin for 6 - 24 h, the growth activity of A2780 cancer cells were studied by [4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) colorimetry. Cellular apoptosis was inspected by flow cytometery and acridine orange-ethidium bromide fluorescent staining methods. The fragmentation of cellular chromosome DNA was detected by DNA ladder, the ultrastructural change was observed under a transmission electron microscope, and the protein levels of nuclear factor-kappa B (NF-kappaB, P65) and cysteinyl aspartate specific protease-3 (Caspase-3) in ovarian cancer cells were measured by immunohistochemistry., Results: After treatment with various concentrations of curcumin, the growth inhibition rates of cancer cells reached 62.05% - 89.24%, with sub-G(1) peaks appearing on histogram. Part of the cancer cells showed characteristic morphological changes of apoptosis under fluorescence and electron microscopes, and the rate of apoptosis was 21.5% - 33.5%. The protein expression of NF-kappaB was decreased, while that of Caspase-3 was increased in a time-dependent manner., Conclusion: Curcumin could significantly inhibit the growth of human ovarian cancer cells; inducing apoptosis through up-regulating Caspase-3 and down-regulating gene expression of NF-kappaB is probably one of its molecular mechanisms.

Our aim was to prepare curcumin derivatives and study their apoptosis-inducing effects on bladder cancer cells in order to establish a basis for targeted chemotherapy of cancer. n-Maleoyl-L-valine-curcumin (NVC) and n-maleoyl-glycine-curcumin (NGC) were chemically synthesized. Intracellular esterase activity of the human bladder cancer EJ cell line and renal tubular epithelial (HKC) cells was examined by 6-carboxyfluorescein diacetate fluorometry. After incubation with NVC or NGC for 6-24 h, cell viability was detected by MTT colorimetry. Cell apoptosis and apoptotic rates were measured by acridine orange/ethidium bromide staining, TUNEL labeling and flow cytometry. Intracellular caspase-3 activities were determined by spectrophotometry. The esterase activity within EJ cells was 10.2-fold higher than that of HKC cells, which was abolished by bis-p-nitrophenylphosphate, an esterase inhibitor, resulting in decreases in NVC- and NGC-mediated cell viability arrest. For EJ cells, the IC50 values of NVC (20.1 micromol/l) and NGC (18.7 micromol/l) were close to curcumin (16.5 micromol/l). Meanwhile, their IC50 values on HKC cells were, respectively, 4.06- and 3.23-fold higher than curcumin. Moreover, NVC and NGC induced apoptosis of EJ cells by 10.13-23.36 and 12.42-28.56%, respectively. Administration of these two derivatives resulted in decreased apoptosis of HKC cells compared with curcumin. The caspase-3 activities of EJ cells, but not of HKC cells, were 5.21- and 5.63-fold enhanced by NVC and NGC, respectively. Thus, novel esterase-sensitive curcumin derivatives were synthesized, which induced extensive apoptosis of bladder cancer EJ cells, but not normal cells.

To study the significance of FasL expression in immune escape of colorectal carcinoma, FasL protein expression and the number of tumor infiltrating lymphocytes (TILs) in 80 specimens of colorectal carcinoma were detected by immunohistochemitry. The mRNA of FasL was measured by in situ hybridization in the consecutive tissue slices of 80 colorectal carcinomas respectively. Using terminal deoxynucleotidyl transferase-mediaed dUTP nick end labeling (TUNEL), apoptotic cells were detected in 80 specimens of colorectal carcinoma. The expression of FasL was detected in all 80 specimens, but it was not even in the same or among different tissues. In the consecutive tissue slices, the location of expression of FasL protein corresponded with that of FasL mRNA. In those with FasL extensive expression, the number of TILs was less than that of FasL weak expression (P < 0.05), and the apoptotic index (AI) of TILs was higher and that of tumor cells was lower than that of FasL with weak expression respectively (P < 0.01). The Al of TILs was correlated with that of tumor cells (r = -0.631, P < 0.01). It was suggested that colorectal carcinoma cells can induce the apoptosis of TILs through the expression of FasL, which can counterattack the immune system. This may be one of the mechanisms of immune evasion in colorectal carcinoma.

X-linked inhibitor of apoptosis (XIAP) is the most potent member of the inhibitor of apoptosis protein (IAP) gene family in terms of its ability to inhibit caspases and suppress apoptosis. Recent evidence has suggested that XIAP is a key determinant in chemoresistance of cancer cells. To explore a novel approach for ameliorating chemotherapy of gastric cancer, the antisense expression vector for the XIAP gene was constructed and transferred into gastric cancer cell lines, MKN-45 (wild-type p53) and MKN-28 (mutant-type p53). This transfer resulted in significant downregulation of XIAP expression, decreased in vitro cell viabilities, and induced apoptosis. In transferred cells, inactive caspase-3 precursors were cleaved into the active subunits (p20 and p17) during apoptosis induced by downregulation of XIAP. The inhibitory effects of cisplatin and mitomycin C on the growth of XIAP downregulated cancer cells were significantly enhanced. In addition, this process occurred only in wild-type p53 (MKN-45), but not in mutant-type p53 (MKN-28) gastric cancer cells. The data presented suggest that downregulation of XIAP via antisense RNA can lead to apoptosis of gastric cancer cells in vitro, correlating with cellular p53 status and activation of caspase-3. This finding could lead to a potential strategy for improving the efficiency of therapies for gastric cancer.

Objective: To investigate the effects of overexpression of second mitochondria-derived activator of caspases (Smac) gene on apoptosis of gastric cancer cells., Methods: Under the induction of liposome, MKN-45 cells were transfected by Smac gene and incubated with G418 for subclone selection. Reverse transcriptase-polymerase chain reaction and Western blot were used to determine cellular Smac gene expression. After induction of apoptosis by mitomycin (MMC), cell viabilities were analyzed using trypan blue stain. Apoptosis was measured by electronic microscopy, acridine orange-ethidium bromide fluorescent staining and in situ terminally labelled transferase technique (TUNEL). Western blot and colorimetry were used to assess cellular caspase-3 expression and its activity., Results: The Smac mRNA and protein levels in MKN-45/Smac subclone cells (subclone consistently expressing Smac gene) were significantly higher than those in MKN-45 (P < 0.01). When compared with those in MKN-45, cell viabilities of MKN-45/Smac were reduced by 10.0% to 30.8% (P < 0.01), after treatment with 10 microg/ml MMC for 6 to 24 hours. Some of the MKN-45/Smac cells showed characteristic morphologic changes of apoptosis, their apoptotic rate being increased by 21.2% (P < 0.01). After treatment with MMC, caspase-3 expression and its activity in MKN-45/Smac cells were significantly higher than those in MKN-45 (P < 0.01)., Conclusions: Overexpression of Smac in gastric cancer cell line significantly improves expression and activity levels of caspase-3 after induction by MMC. Such apoptosis-inducing effect establishes a novel strategy for regulating the apoptosis activity of gastric cancer.

Aim: To explore the feasibility of enhancing apoptosis-inducing effects of chemotherapeutic drugs on human gastric cancer cells by stable transfection of extrinsic Smac gene., Methods: After Smac gene was transferred into gastric cancer cell line MKN-45, subclone cells were obtained by persistent G418 selection. Cellular Smac gene expression was determined by RT-PCR and Western blotting. After treatment with mitomycin (MMC) as an apoptotic inducer, in vitro cell growth activities were investigated by trypan blue-staining method and MTT colorimetry. Cell apoptosis and its rates were determined by electronic microscopy, annexin V-FITC and propidium iodide staining flow cytometry. Cellular caspase-3 protein expression and its activities were assayed by Western blotting and colorimetry., Results: When compared with MKN-45 cells, the selected subclone cell line MKN-45/Smac had significantly higher Smac mRNA (3.12+/-0.21 vs 0.82+/-0.14, t = 7.52, P<0.01) and protein levels (4.02+/-0.24 vs 0.98+/-0.11, t = 8.32, P<0.01). After treatment with 10 microg/mL MMC for 6-24 h, growth inhibition rate of MKN-45/Smac (15.8+/-1.2-54.8+/-2.9%) was significantly higher than that of MKN-45 (5.8+/-0.4- 24.0+/-1.5%, t = 6.42, P<0.01). Partial MKN-45/Smac cancer cells presented characteristic morphological changes of apoptosis under the electronic microscope with an apoptosis rate of 36.4+/-2.1%, which was significantly higher than that of MKN-45 (15.2+/-0.8%, t = 9.25, P<0.01). Compared with MKN-45, caspase-3 expression levels in MKN-45/Smac were improved significantly (3.39+/-0.42 vs 0.96+/-0.14, t = 8.63, P<0.01), while its activities were 3.25 times as many as those of MKN-45 (0.364+/-0.010 vs 0.112+/-0.007, t = 6.34, P<0.01)., Conclusion: Stable transfection of extrinsic Smac gene and its over-expression in gastric cancer cell line can significantly enhance cellular caspase-3 expression and activities, ameliorate apoptosis-inducing effects of mitomycin C on cancer cells, which is a novel strategy to improve chemotherapeutic effects on gastric cancer.

Background: BAK (Bcl-2 homologous antagonist/killer) is a novel pro-apoptotic gene of the Bcl-2 family. It has been reported that gastric tumors have reduced BAK levels when compared with the normal mucosa. Moreover, mutations of the BAK gene have been identified in human gastrointestinal cancers, suggesting that a perturbation of BAK-mediated apoptosis may contribute to the pathogenesis of gastric cancer. In this study, we explored the therapeutic effects of gene transfer mediated elevations in BAK expression on human gastric cancer cells in vitro., Methods: Eukaryotic expression vector for the BAK gene was constructed and transferred into gastric cancer cell lines, MKN-45 (wild-type p53) and MKN-28 (mutant-type p53). RT-PCR and Western Blotting detected cellular BAK gene expression. Cell growth activities were detected by MTT colorimetry and flow cytometry, while apoptosis was assayed by electronic microscopy and TUNEL. Western Blotting and colorimetry investigated cellular caspase-3 activities., Results: BAK gene transfer could result in significant BAK overexpression, decreased in vitro growth, cell cycle G0/G1 arrest, and induced apoptosis in gastric cancer cells. In transferred cells, inactive caspase-3 precursor was cleaved into the active subunits p20 and p17, during BAK overexpression-induced apoptosis. In addition, this process occurred equally well in p53 wild-type (MKN-45), or in p53 mutant-type (MKN-28) gastric cancer cells., Conclusions: The data presented suggests that overexpression of the BAK gene can lead to apoptosis of gastric cancer cells in vitro, which does not appear to be dependent on p53 status. The action mechanism of BAK mediated apoptosis correlates with activation of caspase-3. This could be served as a potential strategy for further development of gastric cancer therapies.

Background & Objective: Curcumin is the major effective component of curcuma, which is a kind of traditional Chinese medicine. It has been paid more attention to curcumin recently for its specific proliferation inhibition and apoptosis inducing effects on tumor cells; however, the involved mechanisms were not clear. This study was designed to explore the apoptosis inducing effects of curcumin on human ovary A2780 cell line and its related molecular mechanisms., Methods: A2780 cancer cells were treated with 10-50 mumol/L curcumin for 6-24 h and the growth inhibition rates of A2780 cancer cells were measured by MTT method. Cell apoptosis was inspected by flow cytometry (FCM) and acridine orange-ethidium bromide fluorescent staining method. The protein levels of NF-kappa B (P65) and Caspase-3 in cancer cells were observed by SP immunohistochemistry., Results: The growth inhibition rates of the cancer cells reached 62.05%-89.24%, with the peak of sub G1 appeared on DNA histogram in FCM. Partial cells presented the characteristic morphological changes of apoptosis under the fluorescent microscope; the apoptosis rates were 21.5%-33.5%. The NF-kappa B (p65) expression was decreased while Caspase-3 expression was increased, which depended on the action time., Conclusions: Curcumin could significantly inhibit the growth of ovary cancer cells; inducing apoptosis through up-regulating Caspase-3 and down-regulating expression of NF-kappa B was probably one of its molecular mechanisms.

Abstract Background BAK (Bcl-2 homologous antagonist/killer) is a novel pro-apoptotic gene of the Bcl-2 family. It has been reported that gastric tumors have reduced BAK levels when compared with the normal mucosa. Moreover, mutations of the BAK gene have been identified in human gastrointestinal cancers, suggesting that a perturbation of BAK-mediated apoptosis may contribute to the pathogenesis of gastric cancer. In this study, we explored the therapeutic effects of gene transfer mediated elevations in BAK expression on human gastric cancer cells in vitro. Methods Eukaryotic expression vector for the BAK gene was constructed and transferred into gastric cancer cell lines, MKN-45 (wild-type p53) and MKN-28 (mutant-type p53). RT-PCR and Western Blotting detected cellular BAK gene expression. Cell growth activities were detected by MTT colorimetry and flow cytometry, while apoptosis was assayed by electronic microscopy and TUNEL. Western Blotting and colorimetry investigated cellular caspase-3 activities. Results BAK gene transfer could result in significant BAK overexpression, decreased in vitro growth, cell cycle G0/G1 arrest, and induced apoptosis in gastric cancer cells. In transferred cells, inactive caspase-3 precursor was cleaved into the active subunits p20 and p17, during BAK overexpression-induced apoptosis. In addition, this process occurred equally well in p53 wild-type (MKN-45), or in p53 mutant-type (MKN-28) gastric cancer cells. Conclusions The data presented suggests that overexpression of the BAK gene can lead to apoptosis of gastric cancer cells in vitro, which does not appear to be dependent on p53 status. The action mechanism of BAK mediated apoptosis correlates with activation of caspase-3. This could be served as a potential strategy for further development of gastric cancer therapies.

Cyclooxygenase (COX)-2 appears to play an important role in gastrointestinal carcinogenesis, and COX-2 overexpression has been demonstrated both in esophageal adenocarcinomas and lymph nodes metastasis. The aim of our study was to investigate the mechanism of growth inhibitory effect of selective inhibition of COX-2 by NS-398 on human cancer cells. The esophageal cancer cell lines (EC9706) that express COX-2 permanently and hepatocellular carcinoma cell lines (SMMC7721) while no expression of COX-2 were studied. Two kinds of cell lines were treated with various concentrations of NS-398 (selective for COX-2 inhibition) at 0.01-0.1 mM for 24 h, 48 h and 72 h. Antiproliferation effect was measured by 3H-TdR incorporation. The cell apoptosis were determined by flow cytometry (FCM) and DNA fragmentation analysis. Survivin was detected by immunocytochemical technique. The growth inhibition could be induced by NS398 in a dose- and time-dependent manner in two kinds of cell lines. FCM analysis revealed a high sub-G1 cell peak in EC9706 group. Agarose electrophroesis showed marked apoptosis ladder pattern, but no apoptosis by NS-398 in SMMC7721. The difference of apoptosis percentage in EC9706 and SMMC7721 was (45.23 ± 1.08)% and (3.05 ± 0.15)% (p < 0.001). After 24 h incubation with NS-398 at concentration of 0.1 dmM, the expression of survivin was markedly reduced in EC9706, but not in SMMC7721. We conclude that the administration of a selective inhibitor of COX-2 significantly decreases cell growth in cancer cell lines by different mechanism. NS-398 could inhibit cell proliferation in cancer cells whether or no COX-2 expression. Nevertheless, apoptosis in the cancer cells expressing COX-2 protein increase more than those lacking COX-2. [ABSTRACT FROM AUTHOR]