Leukotriene B4 receptor inhibitor LY293111 induces cell cycle arrest and apoptosis in human anaplastic large-cell lymphoma cells via JNK phosphorylation.

Anaplastic large-cell lymphoma (ALCL) is a heterogeneous lymphoma category in which a subset of cases carry the t(2;5)(p23;q35) or variant translocations resulting in overexpression of anaplastic lymphoma kinase (ALK). LY293111 (2-[2-propyl-3-[3-[2-ethyl-4-(4-fluorophenyl)-5-hydroxyphenoxy]-propoxy]-phenoxy] benzoic acid sodium salt) is a leukotriene B4 receptor antagonist, which was found to be safe and tolerable in Phase I clinical trials. In this study, we investigated the potential therapeutic effects and mechanisms of action of LY293111 in ALCL cell lines. LY293111 inhibited proliferation of both ALK(+) and ALK(-) ALCL cell in a dose-dependent fashion and induced complete G(1)-S cell cycle arrest, which was accompanied by upregulation of p27 and downregulation of cyclin E. Pretreatment with LY293111 for 4 h resulted in profound inhibition of serum-induced phosphorylation of extracellular-regulated kinases-1 and 2 and Akt and a concomitant increase in the phosphorylation of the stress-activated kinase c-jun N-terminal kinases (JNK). Simultaneously, LY293111 induced caspase-dependent apoptosis via activation of the intrinsic pathway, including early loss of mitochondrial inner transmembrane potential and the production of reactive oxygen species (ROS), cleavage of caspases-9, -3, poly ADP-ribose polymerase (PARP) and X-linked inhibitor of apoptosis. The phospho-JNK inhibitor SP600125 partially protected Sup-M2 cells from LY293111-induced apoptosis, PARP cleavage and ROS generation, suggesting a role for JNK in LY293111-induced cell death. These results warrant further studies of LY293111 in ALCL.     

Arsenic trioxide inhibits proliferation and induces apoptosis in pancreatic cancer cells

Because of the poor therapeutic responsiveness of pancreatic cancer patients, new chemotherapeutic agents for pancreatic cancer would be extremely beneficial. The effects of arsenic trioxide in pancreatic cancer have not been explored. To evaluate the anti-pancreatic cancer effects of arsenic trioxide, three human pancreatic cell lines, HPAF, MiaPaCa-2 and PANC-1, were tested. Arsenic trioxide caused dose- and time dependent inhibition of pancreatic cancer cell proliferation. In parallel with inhibition of cell proliferation, arsenic trioxide induced significant morphological changes, including shrunken cytoplasm, membrane blebbing, and nuclear condensation consistent with apoptosis. Propidium iodide DNA staining showed an increase of the sub-G0/G1 cell population. The DNA fragmentation induced by arsenic trioxide in these three cell lines was confirmed by the TUNEL assay. Furthermore, Western blotting analysis indicated that caspase-3 was activated following arsenic trioxide as measured by procaspase-3 cleavage and PARP cleavage. These findings show that arsenic trioxide has potent anti-proliferative effects on human pancreatic cancer cells with induction of apoptosis in vitro.     

Blockade of cyclooxygenase-2 inhibits proliferation and induces apoptosis in human pancreatic cancer cells

Cyclooxygenase (COX), also referred to as prostaglandin endoperoxide synthase, is a key enzyme in the conversion of arachidonic acid to prostaglandins and other eicosanoids. Epidemiologic, animal and in vitro observations show a positive correlation between the expression of COX (especially COX-2) and colonic cancer development, growth and apoptosis. Constitutive expression of COX-2 in human pancreatic cancer cells was recently reported. To evaluate the potential role of COX in pancreatic cancer, RT-PCR was used to determine the constitutive expression of COX-2 in four pancreatic cancer cell lines. MiaPaCa2, PANC-1, HPAF, ASPC-1. The effect of COX blockade with either the general COX inhibitor, indomethacin, or the specific COX-2 inhibitor, NS-398, on [3H]-thymidine incorporation and cell number was investigated in these four pancreatic cancer cell lines. In addition, the effects of these COX inhibitors on pancreatic cancer cell apoptosis was evaluated by DNA propidium iodide staining and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. All four human pancreatic cancer cell lines expressed COX-2 and their proliferation was concentration- and time-dependently inhibited by both indomethacin andNS398. Substantial apoptosis was also induced by treatment of pancreatic cancer cells with either indomethacin or NS398, as indicated by both DNA propidium iodide staining and the TUNEL assay. Furthermore, indomethacin and NS398 were equipotent for growth inhibition and induction of apoptosis, indicating that eicosanoid synthesis via COX-2 is involved in pancreatic cancer cell proliferation and survival. In conclusion, these findings suggest that the COX pathway, especially COX-2, contributes to the growth and apoptosis of pancreatic cancer. Specific COX-2 inhibitors are likely to be valuable for the treatment and prevention of this deadly cancer.     

Cyclin B1 depletion inhibits proliferation and induces apoptosis in human tumor cells

Cyclin B1 is the regulatory subunit of M-phase promoting factor, and proper regulation of cyclin B1 is essential for the initiation of mitosis. Increasing evidence indicates that the deregulation of cyclin B1 is involved in neoplastic transformation, suggesting the suppression of cyclin B1 could be an attractive strategy for antiproliferative therapy. In the present work, we analysed the impact of small interfering RNAs (siRNAs) targeted to cyclin B1 on different human tumor cell lines. Cyclin B1 siRNAs reduced the protein level of cyclin B1 in HeLa, MCF-7, BT-474 and MDA-MB-435 tumor cells and efficiently reduced the kinase activity of Cdc2/cyclin B1 in HeLa cells. siRNA-treated cells were arrested in G2/M phase in all tumor cell lines tested. Proliferation of tumor cells from different origins was suppressed by 50-80% 48 h after transfection and apoptosis was increased from 5 to 40-50%. Furthermore, tumor cells showed less colony-forming ability after siRNA treatment. In contrast, primary human umbilical vein endothelial cells exhibited only a slight change in cell cycle, and neither apoptosis nor clear inhibition of proliferation was observed after cyclin B1 siRNA treatment for 48 h. These results indicate that siRNAs against cyclin B1 could become a powerful antiproliferative tool in future antitumor therapy.     

Ganoderma lucidum inhibits proliferation and induces apoptosis in human prostate cancer cells PC-3

Ganoderma lucidum (Reishi), an oriental medical mushroom, has been widely used in Asian countries for centuries to prevent or treat different diseases, including cancer. However, the mechanism(s) responsible for the effects of Ganoderma lucidum on cancer cells remain to be elucidated. We have previously demonstrated that Ganoderma lucidum down-regulated the expression of NF-kappaB-regulated urokinase plasminogen activator (uPA) and uPA receptor (uPAR), which resulted in suppression of cell migration of highly invasive human breast and prostate cancer cells. In this study, we investigated the effects of Ganoderma lucidum on cell proliferation, cell cycle, and apoptosis in human prostate cancer cells PC-3. Our data demonstrate that Ganoderma lucidum inhibits cell proliferation in a dose- and time-dependent manner by the down-regulation of expression of cyclin B and Cdc2 and by the up-regulation of p21 expression. The inhibition of cell growth was also demonstrated by cell cycle arrest at G2/M phase. Furthermore, Ganoderma lucidum induced apoptosis of PC-3 cells with a slight decrease in the expression of NF-kappaB-regulated Bcl-2 and Bcl-xl. However, the expression of proapoptotic Bax protein was markedly up-regulated, resulting in the enhancement of the ratio of Bax/Bcl-2 and Bax/Bcl-xl. Thus, Ganoderma lucidum exerts its effect on cancer cells by multiple mechanisms and may have potential therapeutic use for the prevention and treatment of cancer.     

Actinomycin D induces apoptosis and inhibits growth of pancreatic cancer cells

Pancreatic cancer cells are usually resistant to apoptosis induced by cytotoxic drugs, by activation of surface receptors such as Fas and TNF receptor or by serum or growth factor withdrawal. Actinomycin D (actD) is an inhibitor of RNA synthesis and acts as a potent inducer of apoptosis in several cell lines. In the present study, we investigated the effects of actD on PANC-1 pancreatic cancer cells. ActD caused apoptosis in PANC-1 cells in a dose-dependent manner, as determined by cell growth assays, DNA laddering and TUNEL assays. Induction of apoptosis correlated with activation of the JNK/SAPK pathway and increased expression of Bax but not Bad or p53. PANC-1 cells were completely resistant to Fas antibody and TNF-alpha. In contrast, TRAIL decreased the growth of PANC-1 cells by 22%. Low concentrations of actD (10 ng/ml) enhanced the cytotoxic effects of all 3 cytokines. EGF, FGF-2 and IGF-I did not protect PANC-1 cells from actD-mediated apoptosis. ActD (10 ng/ml) also inhibited the growth of CAPAN-1 and T3M4 pancreatic cancer cells but not MiaPaCa-2 cells. Our observations suggest that actD may act via JNK/SAPK and Bax to promote apoptosis in PANC-1 cells and that it may inhibit the growth of other pancreatic cancer cell lines.     

Doxycycline induces caspase-dependent apoptosis in human pancreatic cancer cells

Doxycycline (DC) belongs to the tetracycline family of antibiotics and has been used clinically for over 5 decades. Despite advances in understanding the molecular pathogenesis of pancreatic cancer, no chemotherapy course has shown significant effectiveness. Hence new treatments are needed. In this study we report the pro-apoptotic effects of DC in 2 pancreatic adenocarcinoma cell lines, T3M4 and GER. Cell proliferation was measured using the SRB protein dye. Induction of apoptosis was detected using ELISA. Caspase activation was detected using either immunoblotting or a colorimetric assay based on cleavage of caspase-associated substrates. Expression of proteins and post-translational modifications were determined using immunoblotting. Treatment of pancreatic cancer cells with DC reduces their proliferation. This reduction is, at least partly, due to increased caspase-dependent apoptosis involving activation of caspase3, caspase7, caspase8, caspase9, caspase10 and increased levels of FADD. Inhibition of caspase8 or caspase10 but not caspase9 significantly decreases DC-induced apoptosis in both cell lines. Furthermore treatment of pancreatic cancer cells with DC increases protein levels of Bax and phosphorylation of members of the p38MAPK pathway such as p38MAPK, MKK3/6 and MAPKAPK2. These results provide an insight into mechanisms behind the pro-apoptotic effects of DC in pancreatic cancer cells.     

Ciprofloxacin induces apoptosis and inhibits proliferation of human colorectal carcinoma cells

Efficacy of chemotherapy in advanced stages of colorectal tumours is limited. The quinolone antibiotic ciprofloxacin was recently shown to inhibit growth and to induce apoptosis in human bladder carcinomas cells. We investigated the effect of ciprofloxacin on colon carcinoma lines in vitro. CC-531, SW-403 and HT-29 colon carcinoma and HepG2 hepatoma cells (control cells) were exposed to ciprofloxacin. Proliferation was assessed by bromodeoxyuridine-incorporation into DNA and apoptosis was measured by flow cytometry after propidium iodide or JC-1 staining. Expression of anti-apoptotic Bcl-2 and pro-apoptotic Bax was analyzed by semiquantitative Western blot analysis and activity of caspases 3, 8 and 9 by substrate-cleavage assays. Ciprofloxacin suppressed DNA synthesis of all colon carcinoma cells time- and dose-dependently, whereas the hepatoma cells remained unaffected. Apoptosis reached its maximum between 200 and 500 microg ml(-1). This was accompanied by an upregulation of Bax and of the activity of caspases 3, 8 and 9, and paralleled by a decrease of the mitochondrial membrane potential. Ciprofloxacin decreases proliferation and induces apoptosis of colon carcinoma cells, possibly in part by blocking mitochondrial DNA synthesis. Therefore, qualification of ciprofloxacin as adjunctive agent for colorectal cancer should be evaluated.     

Parthenolide induces proliferation inhibition and apoptosis of pancreatic cancer cells in vitro

Background

To explore the anti-tumor effects of parthenolide in human pancreatic cancer.

Methods

BxPC-3 cell, a human pancreatic cancer, was treated with parthenolide at different concentrations. The MTT assay was used to analyze cell viability. Flow cytometry and DNA fragmentation analysis were applied to evaluate apoptosis after parthenolide treatment. The wound closure and cell invasion assay were also employed in the study. Western blotting was used to demonstrate Bad, Bcl-2, Bax, caspase-9 and pro-caspase-3 expression.

Results

The MTT assay indicated that the pancreatic cancer growth could be dose-dependently inhibited by parthenoolide. This phenomenon was confirmed by flow cytometry and DNA fragmentation analysis. The wound closure assay and cell invasion assay showed that BxPC-3 cell was significantly suppressed by parthenolide at 7.5 μM and 15 μM. Western Blotting demonstrated the Bcl-2 and pro-caspase-3 were down-regulated while the Bax and caspase-9 were up-regulated. No alteration in Bad expression was found after treatment.

Conclusions

The parthenolide can inhibit the cell growth, migration, and induce the apoptosis in human pancreatic cancer. These findings may provide a novel approach for pancreatic cancer treatment.     

Triptolide inhibits proliferation and induces apoptosis of human melanoma A375 cells

Triptolide, a diterpenoid obtained from Tripteryglum wilfordii Hook.f, has attracted interest for its anti- tumor activities against human tumor cell lines in recent years. This report focuses on anti-proliferative and pro-apoptotic activities in human melanoma A375 cells assessed by CCK8 assay, Hoechst 33258 staining and flow cytometry. In addition, triptolide-induced arrest in the S phase was also observed. Caspase assays showed the apoptosis induced by triptolide was caspase-dependent and probably through intrinsic apoptotic pathways. Furthermore, expression of NF-κB (p65) and its downstream factors such as Bcl-2, Bcl-XL was down-regulated. Taken together, the data indicate that triptolide inhibits A375 cells proliferation and induces apoptosis by a caspase-dependent pathway and through a NF-κB-mediated mechanism.     

藤黄酸抑制前列腺癌PC-3细胞增殖并诱导其细胞凋亡

目的:研究中药藤黄的有效成分藤黄酸(gambogic acid,GA)对前列腺癌PC-3细胞增殖和凋亡的影响。方法:采用不同浓度的GA作用前列腺癌PC-3细胞后,在体外通过CCK-8比色法分析细胞的增殖情况,吖啶橙/溴化乙啶(acridine orange/ethidium bromide,AO/EB)双重染色法和FCM法分析细胞的凋亡情况;蛋白质印迹法检测细胞中凋亡相关蛋白P53、Bax和Bcl-2的表达变化。结果:GA不仅能抑制PC-3细胞的增殖,而且能有效诱导其细胞凋亡,与对照组比较差异有统计学意义(P<0.05),并且其抑制增殖和促凋亡作用呈浓度依赖性。CCK-8法检测结果表明,GA浓度>1μmol/L时,细胞的增殖能力受到明显抑制。AO/EB染色法显示,GA处理后的前列腺癌PC-3细胞核呈致密浓染橘红色,并伴有核浓缩和偏向。FCM法检测结果显示,GA处理后的前列腺癌PC-3细胞凋亡峰明显。蛋白质印迹法进一步表明,GA能够上调PC-3细胞中Bax和P53的表达水平,下调Bcl-2表达水平。结论:GA对前列腺癌PC-3细胞具有明显的抑制增殖和诱导凋亡作用。     

FTY720, a synthetic compound from Isaria sinclairii, inhibits proliferation and induces apoptosis in pancreatic cancer cells

FTY720, a synthetic compound produced by modification of a metabolite from Isaria sinclairii, is known as a unique immunosuppressive agent that exerts its activity by inducing apoptosis of lymphocytes [S. Suzuki, FTY720: Mechanisms of action and its effect on organ transplantation, Transplant. Proc. 31 (1999) 2779-2782]. Additionally, it has been found that FTY720 has inhibitory effects on various cancer growth and metastasis [J.D. Wang, S. Takahara, N. Nonomura, Early induction of apoptosis in androgen-independent prostate cancer cell line by FTY720 requires caspase-3 activation, Prostate 40 (1999) 50-55]. To investigate its effect on the growth and metastasis of pancreatic cancer, FTY720 was used to treat three pancreatic cancer cell lines (BxPC-3, AsPC-1, and PANC-1). The MTT assay and flow cytometry were used to evaluate the cell death after FTY720 treatment; the wound closure assay, three-dimensional (3D) Matrigel assay, and invasive assay were used to evaluate the migration, colony formation and invasion abilities after FTY720 treatment, respectively. Protein expression in BxPC-3, AsPC-1, and PANC-1 cells after FTY720 treatment was detected by Western blotting. The MTT assay indicated that the growth of pancreatic cancer cells could be inhibited by FTY720 at various concentrations between 0 and 17 microM in a dose-dependent manner, which was also confirmed by flow cytometry. The wound closure assay, 3D Matrigel assay and cell invasion assay all showed that FTY720 significantly suppressed migration, colony formation and invasion ability of cancer cells at concentrations from 5 to 17 microM. After FTY720 treatment, the phospho-Akt, Bcl-2, pro-caspase-3 expression were down-regulated while the caspase-9 protein expression was increased. In conclusion, FTY720 can inhibit the growth, migration and invasion of pancreatic cancer cells. Our study provides a preclinical support for chemotherapeutic approach with FTY720 for the treatment of pancreatic cancer.     

Bone morphogenetic protein 4 inhibits cell proliferation and induces apoptosis in glioma stem cells

Glioma stem cells (GSCs), which are originated from transformed neural stem cells, are tumor-initiating cells of glioma, the most common primary malignant neoplasm of the central nervous system. Extensive studies have shown that bone morphogenetic protein 4 (BMP4) plays an important role in the differentiation and proliferation of neural stem cells. To seek the functions and mechanisms of BMP4 in GSCs, GSCs isolated from U87 human glioma cells by using vincristine were exposed to BMP4 protein. This study shows that BMP4 inhibited U87 GSC proliferation (p?相似文献   

The synthetic retinoid adapalene inhibits proliferation and induces apoptosis in colorectal cancer cells in vitro

Chemotherapy of advanced stages of colorectal carcinoma is unsatisfactory. Retinoids inhibit cell growth and induce apoptosis in a variety of human malignancies. We compared the effect of the synthetic retinoid adapalene (ADA) and 9-cis-retinoic acid (CRA) on carcinoma cell lines in vitro. Colon carcinoma cell lines CC-531, HT-29 and LOVO as well as human foreskin fibroblasts were exposed to different concentrations of ADA and CRA for 3-72 hr. Proliferation was assessed by BrdU incorporation and apoptosis by FACS analysis. Breakdown of DeltaPsi(m) was determined by JC-1 staining and activity of caspases 3 and 8, by a colorimetric assay. Quantitative Western blots were performed to detect changes in bax, bcl-2 and caspase-3. Both retinoic derivatives suppressed DNA synthesis and induced apoptosis in all tested cell lines time- and dose-dependently. While the natural retinoid CRA showed moderate antiproliferative and proapoptotic effects only at the highest concentration (10(-4) M), the synthetic retinoic ADA was significantly more effective, showing remarkable effects even at 10(-5) M. ADA and CRA disrupt DeltaPsi(m) and induce caspase-3 activity in responsive tumor cells. Quantitative Western blots showed a shift of the bax:bcl-2 ratio toward proapoptotic bax in ADA-treated cells. Our results clearly indicate the superiority of ADA compared to CRA. Therefore, we suggest that ADA may be far more suitable as an adjunctive therapeutic agent for treatment of colon cancer in vivo.     

Phase I and pharmacokinetic study of LY293111, an orally bioavailable LTB4 receptor antagonist, in patients with advanced solid tumors.

PURPOSE: LY293111, a novel diaryl ether carboxylic acid derivative, is a potent and selective inhibitor of the lipoxygenase pathway either directly through 5'-lipoxygenase or via antagonism of the leukotriene B4 (LTB4) receptor. More recently it has been determined to have peroxisome proliferator activated receptor-gamma agonist (PPARgamma) activity. LY293111 has antineoplastic activity in a variety of preclinical models. The tolerability and pharmacokinetics of LY293111 administered continuously, by mouth, BID for repeat cycles of 21 days was evaluated. PATIENTS AND METHODS: Thirty-eight patients with advanced solid tumors were treated at five dose levels (200 to 800 mg BID) for a total of 102 cycles. RESULTS: The most common toxicity was diarrhea (76%). One patient at 600 mg BID (n = 11) and two at 800 mg BID (n = 8), experienced dose-limiting grade 3 diarrhea. Dose reductions and/or delays were infrequent. Increases in steady-state maximum plasma concentration (Cmax,ss) and area under the steady-state plasma concentration time curve 0 to 12 hours (AUCtau,ss) on day 8 could be considered to be dose-proportional over the four-fold-dose range. Interpatient variability in Cmax,ss and AUCtau,ss was estimated to be 65% and 71% respectively. There was a small increase in AUC (1.37; 90% CI, 0.85 to 2.21) between single and multiple doses. Two patients with progressive chondrosarcoma and melanoma had stable disease lasting approximately 336 and 168 days, respectively. CONCLUSION: LY293111 can be administered safely by continuous oral therapy with mild toxicities. Diarrhea is dose-limiting. The recommended phase II dose will be 600 mg BID. The steady-state concentrations in humans exceed relevant levels observed in preclinical models.     

Indomethacin induces apoptosis and inhibits proliferation in chronic myeloid leukemia cells

A nonsteroidal anti-inflammatory drug (NSAID)--indomethacin (IN), was found to induce apoptosis and inhibit proliferation of K562 cells and primary culture bone marrow cells from six chronic myelogenous leukemia (CML) patients. IN induced cells apoptosis and inhibited cells proliferation in a dose-and time-dependent manner, the optimum IN concentration and incubation time for eliciting these effects were 400 micromol/l and 72 h, respectively. A synergic effect on Vp-16 (2.5 microg/ml) induced apoptosis was observed when combined with 100 micromol/l IN in K562 cells. RT-PCR results showed that IN down-regulated Bcl-2 mRNA expression, and did not change Bax mRNA expression; Western blot results confirmed that IN inhibited Bcl-2 protein expression, no influence was found on the translative level of bax protein. Our study indicate that IN induce apoptosis of CML cells by down-regulating Bcl-2 expression partially, and there is a potential significance in the treatment of CML.     

Blockade of cholecystokinin-2 receptor and cyclooxygenase-2 synergistically induces cell apoptosis, and inhibits the proliferation of human gastric cancer cells in vitro

Gastrin and cyclooxygenase-2 (COX-2) play important roles in the carcinogenesis and progression of gastric cancer. However, it remains unknown whether the combination of cholecystokinin-2 (CCK-2) receptor antagonist plus COX-2 inhibitor exerts synergistic anti-tumor effects on human gastric cancer. Here, we demonstrated that the combination of AG-041R (a CCK-2 receptor antagonist) plus NS-398 (a selective COX-2 inhibitor) treatment had synergistic effects on proliferation inhibition, apoptosis induction, down-regulation of Bcl-2 and up-regulation of Bax expression in MKN-45 cells. These results indicate that simultaneous targeting of CCK-2 receptor and COX-2 may inhibit gastric cancer development more effectively than targeting either molecule alone.