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PubMed2006

Enhanced cystatin C and lysosomal protease expression following 6-hydroxydopamine exposure.

6-Hydroxydopamine (6-OHDA) is a selective neurotoxin used to induce apoptosis in catecholamine-containing neurons. Although biochemical products and reactive oxygen species (ROS) of 6-OHDA have been well documented, the activation of cellular pathways following exposure are not well understood. Apoptosis in PC12 (Pheochromocytoma) cells was induced by 6-OHDA in a dose (10-150 microM) and time-dependent (24-72 h) manner compared to experimental controls (no treatment). PC 12 cells exposed to 50 microM 6-OHDA demonstrated the involvement of caspase 3 and lysosomal protease alterations. Following 6-OHDA exposure, the caspase 3-like inhibitor Ac-DEVD-CHO significantly decreased 6-OHDA induced cell death. In addition, alterations in expression of the lysosomal cysteine and aspartic proteases, cathepsin B (CB) and cathepsin D (CD) and the endogenous cysteine protease inhibitor cystatin C were observed utilizing immunocytochemical analysis at 24, 48, and 72 h following 6-OHDA exposure. Furthermore, CB and CD and cystatin C immuno-like reactivity was more pronounced in TUNEL positive cells. Moreover, Western blot analysis confirmed a significant increase in protein expression for CB and CD at 72 h and a temporal and concentration dependent increase in cystatin C in response to 6-OHDA. Cells treated with pepstatin A, an inhibitor for CD, showed a significant decrease in cell death, however, CA-074ME, a specific inhibitor for CB, failed to protect cells from 6-OHDA induced cell death. Thus, these results suggest that apoptosis induced by 6-OHDA exposure is mediated in part through caspase 3 activation and lysosomal protease CD.

Animals↗
PubMed2005

Cannabinoid antagonist AM 281 reduces mortality rate and neurologic dysfunction after cecal ligation and puncture in rats.

OBJECTIVES: The purpose of this study was to examine whether anandamide, an endogenous cannabinoid receptor ligand, is involved in the pathogenesis of septic encephalopathy. DESIGN: Prospective, controlled study. SUBJECTS: Male Wistar rats (7 wks old) were randomly divided into four groups as follows: group 1, control (0.5 mL of saline injected subcutaneously); group 2, sham (surgical abdominal incision and suturing were performed, but ligation and puncture of the cecum were omitted); group 3, cecal ligation and puncture (CLP); group 4, CLP + AM 281 ([N-morpholin-4-yl]-5-[2,4-yl]-5-[2,4-dichlorophenyl]-4-methyl-1H-pyrazole-3-carboxamide) as the cannabinoid receptor antagonist (1 mg/kg intraperitoneally). INTERVENTIONS: Sepsis was induced by CLP under pentobarbital anesthesia (10 mg/kg intraperitoneally) with 1% isoflurane. A 2-Fr high-fidelity micromanometer catheter was inserted into the left ventricle via the right carotid artery to assess hemodynamics. Each of the rats was neurologically assessed at 30 mins and 12, 24, and 48 hrs after the treatment. The cytoplasmic levels of caspase-3 in the hippocampi were assayed before surgery and at 30 mins and 24 and 48 hrs after surgery using Western blotting techniques. To examine the effects of AM 281 on neurologic function and mortality rate, we set another control group treated solely with AM 281. Selective inducible nitric oxide synthase inhibitor, L-N6-(1-iminoethyl)-lysine (4 mg/kg), was injected intraperitoneally immediately after CLP to produce the CLP + L-N6-(1-iminoethyl)-lysine group to exclude the influence of depressed hemodynamics on neurologic impairment. MEASUREMENTS AND MAIN RESULTS: It was found that administration of AM 281 could prevent the hemodynamic changes induced by sepsis. Reflex responses, including the pinna, corneal, paw or tail flexion, and righting reflexes, and the escape response significantly decreased in the CLP and CLP + L-N6-(1-iminoethyl)-lysine groups at 48 hrs after the surgery. In contrast, no changes in these reflex responses were found between the CLP + AM 281 and control and sham groups. In addition, no effects of the administration of AM 281 on neurologic function and mortality rate in the control group were found. Tissue caspase-3 levels were elevated at 48 hrs after CLP in the CLP alone group (means +/- sd: control, 3.9 +/- 0.4; sham, 4.2 +/- 0.4; CLP, 7.1 +/- 1.0 [p < .01]; CLP + AM 281, 4.0 +/- 0.5 densitometric units). In addition, administration of AM 281 also decreased the mortality rate (p < .05). CONCLUSIONS: Administration of AM 281 prevented the hemodynamic changes and development of neurologic dysfunction occurring in association with septic shock, and could decrease the mortality rate in experimentally induced septic shock in rats. Although further studies are necessary to determine whether endogenous cannabinoids cause septic encephalopathy in rats directly or via their effects on systemic hemodynamics, the beneficial effects of AM 281 on these rats might have significant therapeutic implications in cases of septic encephalopathy.

Animals↗
PubMed2004

Class I histone deacetylase-selective novel synthetic inhibitors potently inhibit human tumor proliferation.

We have developed previously a class of synthetic hybrid histone deacetylase (HDAC) inhibitors, which were built from hydroxamic acid of trichostatin A and pyridyl ring of MS-275. In this study we evaluated the antitumor effects of these novel hybrid synthetic HDAC inhibitors, SK-7041 and SK-7068, on human cancer cells. Both SK-7041 and SK-7068 effectively inhibited cellular HDAC activity at nanomolar concentrations and induced the time-dependent hyperacetylation of histones H3 and H4. These HDAC inhibitors preferentially inhibited the enzymatic activities of HDAC1 and HDAC2, as compared with the other HDAC isotypes, indicating that class I HDAC is the major target of SK-7041 and SK-7068. We found that these compounds exhibited potent antiproliferative activity against various human cancer cells in vitro. Growth inhibition effect of SK-7041 and SK-7068 was related with the induction of aberrant mitosis and apoptosis in human gastric cancer cells. Both compounds induced the accumulation of cells at mitosis after 6 h of treatment, which was demonstrated by accumulation of tetraploid cells, lack of G(2) cyclin/cyclin-dependent kinase inactivation, and higher mitotic index. After 12 h of treatment, apoptotic cells were increased through mitochondrial and caspase-mediated pathway. Finally, in vivo experiment showed that SK-7041 or SK-7068 was found to reduce the growth of implanted human tumors in nude mice. Therefore, based on isotype specificity and antitumor activity, SK-7041 and SK-7068 HDAC inhibitors are expected to be promising anticancer therapeutic agents and need additional clinical development.

Amides↗
PubMed2005

Caspase-dependent apoptosis induction by phenethyl isothiocyanate, a cruciferous vegetable-derived cancer chemopreventive agent, is mediated by Bak and Bax.

PURPOSE: The present study was undertaken to gain insights into the molecular mechanism of apoptosis induction by phenethyl isothiocyanate (PEITC) using prostate cancer cell lines derived from transgenic adenocarcinoma mouse prostate (TRAMP) mice (TRAMP-C1 and TRAMP-C2). EXPERIMENTAL DESIGN AND RESULTS: The viability of TRAMP-C1 and TRAMP-C2 cells was reduced significantly in the presence of PEITC in a concentration-dependent manner as determined by sulforhodamine B and trypan blue dye exclusion assays. Treatment of TRAMP-derived cells with PEITC revealed features characteristic of apoptosis induction, including appearance of subdiploid cells (determined by flow cytometry), cytoplasmic histone-associated DNA fragmentation (determined by an ELISA assay), and cleavage of caspase-3 (determined by immunoblotting). The PEITC-induced apoptosis in TRAMP-derived cells was associated with a marked increase in the level of proapoptotic protein Bak and/or a decrease in the levels of antiapoptotic protein Mcl-1 or Bcl-xL and disruption of mitochondrial membrane potential. The SV40 immortalized mouse embryonic fibroblasts derived from Bak and Bax double knockout mice were significantly more resistant to PEITC-induced DNA fragmentation compared with wild-type or Bak-/- mouse embryonic fibroblasts. The PEITC-induced apoptosis in both cell lines was significantly attenuated in the presence of caspase inhibitors zVAD-fmk, zLEHD-fmk, and zIETD-fmk. Oral administration of PEITC (9 or 12 micromol PEITC/d, Monday-Friday) significantly retarded growth of TRAMP-C1 xenografts in nude mice without causing weight loss or any other side effects. CONCLUSION: The results of the present study indicate that caspase-dependent apoptosis by PEITC is mediated by Bak and Bax proteins.

Adenocarcinoma↗
PubMed2001

In vitro induction of apoptosis of neoplastic cells in low-grade non-Hodgkin's lymphomas using combinations of established cytotoxic drugs with bendamustine.

BACKGROUND AND OBJECTIVES: Regulation of apoptotic cell death is being increasingly recognized as a mechanisms by which cytostatic agents mediate tumor cell death. Preliminary clinical studies with bendamustine, an alkylating agent with a purine nucleus, provide strong evidence that this drug is a highly effective cytostatic in low grade lymphomas. Therefore, we investigated the in vitro activity of bendamustine in combination with other established cytotoxic drugs. DESIGN AND METHODS: 2 lines (DOHH-2, WSU-NHL) and mononuclear cells (MNC) from patients with leukemic low-grade B-non-Hodgkin's lymphoma (NHL) (n=10), T-NHL (n=7) and chronic lymphocytic leukemia (CLL) (n=12). Apoptosis (7-AAD), depolarization of mitochondrial membrane potential (MMP, JC-1), caspase-3-activity (FIENA) and cell proliferation (XTT/WST-1) were determined. Several incubation times and drug dosages (for IC(30/50/75/90)) were studied. Synergistic, additive or antagonistic effects were calculated by a median plot effect and the combination index (CI) method. RESULTS: In general, combinations of bendamustine with mitoxantrone or doxorubicin resulted in antagonistic effects in the tested cell lines and the MNC from the patients. CI-calculation failed in these cases since there was not a sufficient dose response. On the other hand, the combination of bendamustine with 2-CdA showed synergistic in vitro activity on the tested cell lines, neoplastic lymphocytes from patients with peripheral T-cell lymphomas and partially on MNC from patients with CLL and B-NHL. The antagonism of the combination of bendamustine and anthracyclines appeared to be due to inhibition of depolarization of mitochondrial-membrane potential and caspase-3-activity during apoptosis of the studied cell lines. INTERPRETATION AND CONCLUSIONS: In conclusion, our results suggest that schedules using combinations of bendamustine and anthracyclines should not be recommended for the treatment of low-grade NHL, whereas bendamustine combined with 2-CdA could be considered for the development of future treatment strategies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

[An experimental study of the therapeutical effect of bFGF in retinal ischemia/reperfusion injury].

OBJECTIVE: To investigate the therapeutical effect of basic fibroblast growth factor (bFGF) on retina ischemia/reperfusion injury. METHOD: Experimental retinal ischemia/reperfusion injury was induced by increasing intraocular pressure of rats eyes. 48 rats were divided into groups of control, ischemia/reperfusion and bFGF-treated, randomly. Apoptotic cells were detected using the TdT-dUTP terminal nick-end labeling at 1 hour, 6 hours, 12 hours, 24 hours, and 72 hours after reperfusion. The expression of caspase-3 at specified times was determined by Streptavidin Peroxidase immunohistochemistry. Atomic absorption spectrum method was used to evaluate the intracellular calcium changes of retinal tissues. RESULTS: In ischemia group, apoptotic cells began to appear at 6th hour after reperfusion and increased progressively with time. The number of apoptotic cells reached the peak 24 hour after reperfusion, and no apoptotic cells could be found at 72 hours. Changes in caspase-3 expression followed a similar trend. The intracellular calcium level of rat retina began to increase at 1 hour after reperfusion, and continued to increase with the reperfusion time. At 24 hours after reperfusion the intracellular calcium level reached the peak, and decline thereafter up to 72 hours. The patterns of change of the three markers of treatment group were similar to the above. However, the magnitude of changes was relatively lower. A statistically significant difference (P < 0.05) between the ischemia group and treatment group at 6th, 12th and 24th after reperfusion was observed. CONCLUSION: Apoptosis may play a vital role in ischemia-reperfusion injury of the retina. bFGF may have a therapeutical effect on ischemia-reperfusion injury by inhibiting the increase of retinal intracellular calcium stores and caspase-3 protein expression.

Animals↗
PubMed2006

Involvement of BH3-only proapoptotic proteins in mitochondrial-dependent Phenoxodiol-induced apoptosis of human melanoma cells.

Phenoxodiol is a chemically modified analogue of the plant hormone isoflavone with antitumour activities. In the present study, we have examined its ability to induce apoptosis in human melanoma cells and the mechanisms involved. Apoptosis was observed in Phenoxodiol-treated cells by using annexin V/propidium iodide staining and determining mitochondrial membrane potential. To determine which caspase pathways were involved in Phenoxodiol-induced apoptosis, studies were performed using specific caspase inhibitors. Western studies were performed to ascertain which proteins of the apoptosis cascade were affected to cause Phenoxodiol-induced apoptosis. We found that induction of apoptosis by Phenoxodiol was maximal at 48 h with a range of apoptosis of 12+/-4 to 48+/-5% in different melanoma lines. This apoptosis was mainly dependent on activation of caspase-3 and caspase-9. Apoptosis was associated with induction of changes in mitochondrial membrane potential and was inhibited by over-expression of Bcl-2. Variation in sensitivity to Phenoxodiol appeared related to events upstream of the mitochondria and the degree of conformational change in Bax. The p53-regulated BH3-only proteins (Bad, PUMA and Noxa) were increased in the sensitive, but not in the resistant lines, whereas Bim was increased in all the lines tested. Bim appeared, however, to be partially involved because reduction of Bim by RNA interference resulted in decreased levels of apoptosis. Together, these studies suggest that Phenoxodiol induces apoptosis of melanoma cells by induction of p53-dependent BH3 proteins (Bad, PUMA and Noxa) and the p53-independent Bim protein, resulting in activation of Bax and its downstream events.

Apoptosis↗
PubMed2000

Adenovirus-mediated hepatocyte growth factor gene transfer prevents lethal liver failure in rats.

Hepatocyte growth factor (HGF) has a potent antiapoptotic effect on hepatocytes in D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-treated rats. Here, we report that adenovirus mediated HGF gene transfer into liver prevents liver failure and reduces mortality of rats treated with d-GalN/LPS. Fisher 344 rats, which were given intraperitoneal injections of pAxCAHGF 48 h before, were treated with D-GalN/LPS. Serum ALT in the HGF group at 6 and 12 h after D-GalN/LPS was decreased to 1/6 and 1/12 of the control group (P < 0.01, each). Concomitant reduction of apoptotic cells were also observed. The Kaplan-Meier analysis showed that a survival rate in the HGF group was improved, compared to that in the control group (P < 0.05). Caspase-3 activity in the HGF group decreased, compared to that in the control group, especially at 12 h (P < 0.05), although it maintained a high level in the control group. Expression of Bcl-xL and cyclooxygenase-2 (Cox-2) was induced in liver by HGF gene transfer. These data suggest that HGF exerts an antiapoptotic effect through dual induction of Bcl-xL and Cox-2, which suppresses caspase-3 activity.

Adenoviridae↗
PubMedDate not supplied

Ethanolic neem (Azadirachta indica) leaf extract induces apoptosis in the hamster buccal pouch carcinogenesis model by modulation of Bcl-2, Bim, caspase 8 and caspase 3.

Induction of apoptosis is one of the most active strategies in cancer chemoprevention and the ability of medicinal plants in this regard has attracted major research interest. The present study was designed to investigate the apoptosis inducing capacity of an ethanolic neem leaf extract (ENLE) during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis using the apoptosis-associated proteins Bcl-2, Bim, caspase 8 and caspase 3 as markers. Topical application of DMBA to the hamster cheek pouch for 14 weeks resulted in well developed squamous cell carcinomas associated with increased expression of Bcl-2 and decreased expression of Bim, caspase 8 and caspase 3. Administration of ENLE inhibited DMBA-induced hamster buccal pouch (HBP) carcinogenesis, as revealed by the absence of neoplasms, with induction of Bim and caspases 8 and 3 and inhibition of Bcl-2 expression. Our results suggest that the chemopreventive effects of ENLE may be mediated by induction of apoptosis.

Animals↗
PubMed1999

15-Deoxy-Delta(12,14)-prostaglandin J(2), a ligand for peroxisome proliferator-activated receptor-gamma, induces apoptosis in JEG3 choriocarcinoma cells.

Apoptosis has been described in placental (trophoblast) tissues during both normal and abnormal pregnancies. We have studied the effects of the cyclopentenone prostaglandins (PGs) on trophoblast cell death using JEG3 choriocarcinoma cells. PGJ(2), Delta(12)PGJ(2), and 15-deoxy-Delta(12,14)-PGJ(2) (15dPGJ(2)) (10 microM) significantly reduced mitochondrial activity (MTT assay) over 16 h by 17.4 +/- 4.7%, 28 +/- 9.3%, and 62.5 +/- 2.8%, respectively (mean +/- sem), while PGA(2) and PGD(2) had no effect. The synthetic PPAR-gamma ligand ciglitizone (12.5 microM) had a potency similar to 15dPGJ(2) (69 +/- 3% reduction). Morphological examination of cultures treated with PGJ(2) and its derivatives revealed the presence of numerous cells with dense, pyknotic nuclei, a hallmark of apoptosis. FACS analysis revealed an abundance (approximately 40%) of apoptotic cells after 16-h treatment with 15dPGJ(2) (10 microM). The caspase inhibitor ZVAD-fmk (5 microM) significantly diminished the apoptotic effects of Delta(12)PGJ(2) and 15dPGJ(2). JEG3 cells expressed PPAR-gamma mRNA by Northern analysis. These novel findings imply a role for PPAR-gamma ligands in various processes associated with pregnancy and parturition.

Amino Acid Chloromethyl Ketones↗
PubMed2001

[Effect of hypoxia-ischemia on cysteinyl aspartate-specific proteinases activity in cerebral tissue of neonatal rat].

OBJECTIVE: To study the effect of hypoxia-ischemia on cysteinyl aspartate-specific proteinases (caspase-3) activity in cerebral tissue of neonatal rat and probe into its significance. METHODS: To induce hypoxio-ischemic brain damage (HIBD), the left carotid artery of rats at day 7 was ligated and animals were exposed to 8% oxygen for 2 hours. 0.5, 12, 24, and 48 hours after HIBD, both ipsilateral and contralateral cerebral tissue were ditected and homogenized, caspase-3 activity was measured by cleavage of the colorimetric substrate DEVD-pNA. RESULTS: Caspase-3 activity in ipsilateral cerebral tissue increased gradually after HIBD and peaked at 24 hours, and then decreased significantly at 48 hours(P < 0.001). There were no significant changes in caspase-3 activity in the contralateral tissue at all time points (P > 0.05). CONCLUSIONS: Significant activation of caspase-3 after cerebral hypoxia-ischemia strongly suggests that apoptosis is involved in HIBD. Application of caspase inhibitors or other anti-apoptotic agents may become a new therapeutics of HIBD.

Animals↗
PubMed2002

In vivo and in vitro activation of caspase-8 and -3 associated with Helicobacter pylori infection.

In vivo and in vitro studies have shown an increase in apoptosis in gastric epithelial cells in persons infected with Helicobacter pylori. H. pylori-induced activation of caspase-8 and -3 was evaluated using a human gastric adenocarcinoma cell line (AGS) and gastric tissue from humans and monkeys colonized with H. pylori. The enzymatic activity of caspase-8 was detected only in AGS cells exposed to H. pylori up to 24 h. The active form of caspase-8 was present by Western blot after exposure to H. pylori for 3 h and persisted through 24 h. Caspase-3 activity was present in AGS cells exposed to H. pylori for 3 h, reaching a maximum after 24 h (a sevenfold increase in activity). Caspase-8-mediated cleavage of procaspase-3 generated a 20-kDa band (indicative of the presence of active caspase-3) present only in AGS cells exposed to H. pylori. Active caspase-3 staining was markedly increased in gastric mucosa from infected persons and animals, compared to uninfected controls by immunohistochemistry. Stimulation of downstream events leading to apoptosis, such as the cleavage of PARP (poly adenosine-diphosphate-ribose polymerase) and DFF45 (DNA fragmentation factor 45) as a result of activation of caspase-3, was evaluated. PARP was cleaved, resulting in the presence of both an 89- and a 24-kDa band along with DFF45, resulting in the presence of 10- and 12-kDa bands only in gastric cells exposed to H. pylori. Our data show that H. pylori stimulates the activation of caspases and downstream mediators of caspase-induced apoptosis. This suggests that H. pylori-induced apoptosis is mediated through caspase pathways, which include the activation of caspase-8 and subsequent cleavage and activation of caspase-3. This is consistent with caspase-3 activation that was found in the gastric mucosa of humans and monkeys infected with H. pylori.

Animals↗
PubMed2002

Protein synthesis-dependent apoptotic signalling pathway in X-irradiated MOLT-4 human leukaemia cell line.

PURPOSE: To demonstrate whether protein synthesis is required for ionizing radiation-induced apoptosis through activation of caspases in human leukaemia cell line MOLT-4, the effects of a protein synthesis inhibitor, cycloheximide, on the apoptotic signalling pathway including the activation of caspase family and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), and the expression of Fas/CD95/APO-1 (Fas) were examined in X-irradiated MOLT-4 cells. MATERIALS AND METHODS: MOLT-4 cells pretreated with 0.5 microg/ml cycloheximide for 1h were exposed to 7.5Gy of X-rays. The appearance of apoptosis, expression of Fas, activation of caspases-3, -8, -9, SAPK/JNK and AP-1, the release of mitochondrial cytochrome-C and the formation of death-induced signalling complex (DISC) between Fas and the Fas-associated death domain (FADD) were measured by fluorescence microscopy, Western blotting, flow cytometry, gel shift assay and immunoprecipitation, respectively. RESULTS: Nuclear fragmentation and chromatin condensation were observed at 6 h after X-irradiation and gradually increased up to 12 h. These phenomena were significantly attenuated by cycloheximide. Cycloheximide also inhibited the activation of caspases and AP-1, the expression of Fas, the formation of DISC and the release of cytochrome-C, but not the activation of SAPK/JNK in X-irradiated MOLT-4 cells. CONCLUSION: These results indicate that apoptosis of X-ray-induced MOLT-4 cells is dependent on the activation of caspases regulated by de novo protein synthesis through SAPK/JNK activation.

Apoptosis↗
PubMed2006

Short photoperiod-induced ovarian regression is mediated by apoptosis in Siberian hamsters (Phodopus sungorus).

Siberian hamster reproduction is mediated by photoperiod-induced changes in gonadal activity. However, little is known about how photoperiod induces cellular changes in ovarian function. We hypothesized that exposing female hamsters to short (inhibitory) as opposed to long (control) photoperiods would induce an apoptosis-mediated disruption of ovarian function. Ovaries and plasma from hamsters exposed to either long (LD, 16 h light:8 h darkness) or short (SD, 8 h light:16 h darkness) days were collected during diestrus II after 3, 6, 9 and 12 weeks and processed for histology or RIA respectively. Apoptosis was assessed by in situ TUNEL and active caspase-3 protein immunolabeling. No significant differences were observed among LD hamsters for any parameter; therefore, these control data were pooled. SD exposure induced a decline in preantral follicles (P < 0.05), early antral/antral follicles (P < 0.01) and corpora lutea (P < 0.01) by week 12 as compared with LD. Terminal atretic follicles appeared by SD week 9; by week 12, these had become the predominant ovarian structures. Estradiol concentrations decreased by weeks 9 and 12 SD when compared with both LD and week-3 SD hamsters (P < 0.05); however, no changes were observed for progesterone. TUNEL-positive follicles in SD ovaries increased at week 3 and subsequently declined by week 12 as compared with LD ovaries (P < 0.01). Active capsase-3 protein immunostaining peaked at SD week 3 as compared with all other groups (P < 0.01). TUNEL and capsase-3 immunolabeling were localized to granulosa cells of late-preantral and early-antral/antral follicles. These data indicate that SD exposure rapidly induces follicular apoptosis in Siberian hamsters, which ultimately disrupts both estradiol secretion and folliculogenesis, resulting in the seasonal loss of ovarian function.

Animals↗
PubMed2005

Adenosine triphosphate induces activation of caspase-3 in apoptosis of human granulosa-luteal cells.

Adenosine triphosphate (ATP) has been shown to induce programmed cell death in various systems. However, little is known about the effect of ATP on human granulosa-luteal cells (hGLCs). The present study was designed to examine the effect of ATP on the activation of the caspase signaling pathway and its role in inducing programmed cell death. Human GLCs were collected from patients undergoing in vitro fertilization programs, and then were cultured in FBS-supplemented DMEM for 3 days prior to our studies. To examine the dose-response relationship, hGLCs were treated with increasing concentrations of ATP (10 microM, 100 microM, 1 mM or 10 mM) for 24 hours. For time-course experiments, hGLCs were treated with 10 mM ATP for 6, 12, or 24 hours. Western blot analysis was performed using antibodies against the pro- and active forms of caspase-3, -9, or PARP. To quantify the induction of apoptosis, DNA fragmentation was measured using the cell death detection enzyme-linked immunosorbent assay. To examine the effect of human chorionic gonadotropin (hCG) in protecting cells from apoptosis, hGLCs were treated with 10 IU hCG in the presence of 10 mM ATP for 12 hours. It was demonstrated that ATP was capable of inducing DNA fragmentation in a dose- and time-dependent manner. Furthermore, Western blot analysis, which detected the pro- and active forms of caspase-3, or PARP, demonstrated that ATP activated the caspase-signaling pathway, leading to the proteolytic conversion of pro-caspase-3 to active caspase-3, and the subsequent cleavage of the caspase substrate PARP. Based on our observation, caspase-9 was not triggered by ATP. Interestingly, hCG attenuated the effect of ATP in activating the caspase signaling pathway. To our knowledge, this is the first demonstration of the ATP-induced activation of the caspase signaling pathway in the human ovary. These results support the notion that the caspase-signaling pathway is involved in mediating ATP actions in the human ovary.

Adenosine Triphosphate↗
PubMed2005

Evaluation of targeted arterial delivery of the branched chain fatty acid 12-methyltetradecanoic acid as a novel therapy for solid tumors.

The purpose of this research was to evaluate the effects of targeted arterial delivery of the branched chain fatty acid 12-methyltetradecanoic acid (12-MTA) on the VX2 squamous cell carcinoma in rabbits. An intramuscular VX2 squamous cell carcinoma was induced at a single site in the right thigh of 39 New Zealand white rabbits. Approximately 10 days after inoculation, a 3-French catheter was introduced into the right common carotid artery and positioned using fluoroscopic guidance in the right deep femoral artery, which was the main, if not exclusive, artery supplying the tumor. Ethiodol alone (targeting agent), Ethiodol containing 12-MTA, or Ethiodol containing myristic acid was then injected through the catheter. Tumor growth and histopathology were evaluated 7-8 days after treatment. Caspase-3 activity was evaluated 2 days after therapy, and tumor tissues were assayed for eicosanoid metabolites 2 and 7 days after treatment to assess the effects of the branched chain fatty acid on the lipoxygenase (LOX) and cyclooxygenase-2 (COX-2) enzyme systems. Targeted arterial delivery of 12-MTA resulted in dose-dependent growth inhibition of intramuscular rabbit VX2 tumors while myristic acid, a saturated fatty acid of the same carbon length as 12-MTA, was found to stimulate tumor growth. Two and 7 days following treatment, tumors treated with 12-MTA showed a significant decrease in 5-hydroxyeicosatetraenoic acid (5-HETE) and a concomitant increase in 15-HETE levels while tumors treated with myristic acid exhibited a significant increase in prostaglandin E2 (PGE2) levels. Western blot as well as immunohistochemical analysis showed that 5-LOX and COX-2 proteins were present in the VX2 tumors. No alterations in tumor/tumor cell morphology or caspase-3 activity were evident on microscopic examination following treatment. These studies suggest that targeted arterial delivery of branched chain fatty acids such as 12-MTA may be considered as a potential new therapy for treatment of solid tumors. The exact mechanism(s) responsible for the observed inhibition of VX2 tumor growth by 12-MTA is unclear. Additional in vivo studies are warranted to elucidate 12-MTA's mechanism of action and further investigate the branched chain fatty acid's antitumor effects.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed2005

Serenoa repens treatment modifies bax/bcl-2 index expression and caspase-3 activity in prostatic tissue from patients with benign prostatic hyperplasia.

PURPOSE: Permixon is a lipidosterolic extract of Serenoa repens (SR) widely used to treat men with benign prostatic hyperplasia (BPH). We tested the effect of this drug on molecular mechanisms associated with apoptosis, such as the Bax-to-Bcl-2 expression ratio and caspase-3 activity, in prostatic tissue from men with symptomatic BPH treated for 3 months before surgery. MATERIALS AND METHODS: An open, multicenter pilot study of 2 parallel groups of patients with BPH was done. They were randomized to be followed for 3 weeks without any treatment before surgery (control group) or to receive 160 mg SR orally twice daily for a 3-month period preceding the same surgery. Surgery was ultimately performed in 17 controls and 12 patients by transurethral prostate resection or retropubic adenomectomy. Bax and Bcl-2 expression, and caspase-3 activity were determined by Western blot in 15 controls and 10 patients, and reported in blinded fashion. RESULTS: The Bax-to-Bcl-2 ratio, which is used as an apoptotic index, was significantly increased in the prostatic tissue of treated patients. The level of the intact 116 kDa poly (adenosine diphosphate-ribose) polymerase form, an enzyme involved in the cell death apoptotic pathway, was also found to be decreased in prostatic tissue from SR treated patients, suggesting increased caspase 3 activity in the prostate. CONCLUSIONS: Permixon increased molecular markers involved in the apoptotic process, ie the Bax-to-Bcl-2 expression ratio and caspase-3 activity. This could have clinical relevance due to the improvement in symptoms produced by treatment with this drug.

Aged↗
PubMed2006

Pannarin inhibits cell growth and induces cell death in human prostate carcinoma DU-145 cells.

In the course of our continuing search for new natural anticancer compounds for treatment and/or prevention of prostate cancer, our laboratory has focused its search on poorly investigated lichen metabolites, sphaerophorin, pannarin and epiphorellic acid-1. To this end, we treated DU-145, a cell line resembling the last stage of prostate carcinoma, with different concentrations (6-50 micromol/l) of these compounds for 72 h. Our data clearly evidenced that these lichen metabolites inhibit the growth of human prostate carcinoma DU-145 cells, but pannarin exhibits a higher effect. Our data show an induction of apoptotic death of advanced prostate cancer cells by sphaerophorin, pannarin and epiphorellic acid-1. In fact, a significant (P<0.001) increase in caspase-3 enzyme activity occurred in DU-145 cells treated with all lichen compounds at 12 and 25 micromol/l concentrations, correlated to a high DNA fragmentation, but without the disruption of the plasma membrane, as evaluated by the percentage of lactic dehydrogenase release. Alternatively, we found a low, but significant (P<0.01) lactic dehydrogenase release at higher concentrations (50 micromol/l), suggesting that in these experimental conditions sphaerophorin, pannarin and epiphorellic acid-1 induce necrosis in DU-145 cells, through the increase in reactive oxygen species generation. The experimental evidence is further confirmed by caspase-3 activity results, evidencing a reduction in the activity of this protease at a higher concentration, 50 micromol/l.

Antineoplastic Agents, Phytogenic↗