Chinese expert consensus on drug interaction management of poly ADP-ribose polymerase inhibitors / 中华肿瘤杂志

Poly ADP-ribose polymerase inhibitors (PARPi), which approved in recent years, are recommended for ovarian cancer, breast cancer, pancreatic cancer, prostate cancer and other cancers by The National Comprehensive Cancer Network (NCCN) and Chinese Society of Clinical Oncology (CSCO) guidelines. Because most of PARPi are metabolized by cytochrome P450 enzyme system, there are extensive interactions with other drugs commonly used in cancer patients. By setting up a consensus working group including pharmaceutical experts, clinical experts and methodology experts, this paper forms a consensus according to the following steps: determine clinical problems, data retrieval and evaluation, Delphi method to form recommendations, finally formation expert opinion on PARPi interaction management. This paper will provide practical reference for clinical medical staff.

Precision Medicine, Artificial Intelligence, and Genomic Markers in Urology. Do we need to Tailor our Clinical Practice? / Medicina de precisión, inteligencia artificial y marcadores genómicos en urología. ¿Debemos cambiar nuestra práctica clínica?

Precision medicine plays a key role in urological oncology practice nowadays, with the breakthrough of the poly (ADP-ribose) polymerase inhibitors (PARPi), which play a critical role in different DNA damage repair (DDR) pathways, the immune checkpoint inhibitors, the genomic expression profiles and current genome manipulation-directed targeted therapy. Information and technology (IT) are set to change the way we assess and treat patients and should be reviewed and discussed. The aim of the present article is to demonstrate a detailed revision on precision medicine, including novel therapeutic targets, genomic markers, genomic stratification of urological patients, and the top-notch technological breakthroughs that could change our clinical practice We performed a review of the literature in four different databases (PubMed, Embase, Lilacs, and Scielo) on any information concerning prostate, bladder, kidney and urothelial cancer novel treatments with PARPi, immune checkpoint inhibitors (ICIs), targeted therapy with fibroblast growth factor receptor inhibitors (FGFRi), and theranostics with prostate-specific membrane antigen (PSMA) targeted monoclonal antibodies. Artificial intelligence, machine learning, and deep learning algorithm in urological practice were also part of the search. We included all articles written in English, published within the past 7 years, that discussed outstanding therapies and genomics in urological cancer and artificial intelligence applied to urology. Meanwhile, we excluded articles with lack of a clear methodology and written in any other language than English. One-hundred and twenty-six articles of interest were found; of these, 65 articles that presented novel treatments of urological neoplasms, discussed precision medicine, genomic expression profiles and biomarkers in urology, and latest deep learning and machine learning algorithms as well as the use of artificial intelligence in urological practice were selected. A critical review of the literature is presented in the present article. Urology is a constantly changing specialty with a wide range of therapeutic breakthroughs, a huge understanding of the genomic expression profiles for each urological cancer and a tendency to use cutting-edge technology to treat our patients. All of these major developments must be analyzed objectively, taking into account costs to the health systems, risks and benefits to the patients, and the legal background that comes with them. A critical analysis of these new technologies and pharmacological breakthroughs should be made before considering changing our clinical practice. Nowadays, research needs to be strengthened to help us improve results in assessing and treating our patients

La medicina de precisión juega un rol fundamental en la práctica clínica de la urologia oncológica en la actualidad, con el desarrollo de los inhibidores de la poli (ADP-ribosa) polimerasa (PARPi), que juegan un papel fundamental en las distintas vías del reparo del ADN dañado (RAD), los inhibidores del punto de chequeo inmune (ICI), los perfiles de expresión genómicos, y la terapia blanco-dirigida a la manipulación genómica. El desarrollo tecnológico y la informática están cambiando la forma como evaluamos y tratamos a los pacientes, y se debe discutir y revisar a detalle. El objetivo de este artículo es hacer una revisión detallada acerca de la medicina de precisión, genómica, y los avances tecnológicos en nuestro campo. Realizamos una revisión de la literatura en cuatro bases de datos diferentes (PubMed, Embase, Lilacs, y Scielo), buscando cualquier información relacionada con cáncer de próstata, vejiga, riñón y carcinoma urotelial, tratamientos novedosos con PARPi, ICI, terapia-blanco con inhibidores del receptor del factor de crecimiento de los fibroblastos (FGFRi) y teragnósticos con anticuerpos monoclonales dirigidos al antígeno de membrana específico de la próstata (AMEP). Inteligencia artificial, aprendizaje de máquinas y algoritmos de aprendizaje profundo en la práctica urológica también fueron revisados. Incluimos artículos escritos en inglés, publicados dentro de los últimos 7 años, que abordaran terapias novedosas y genómica en cáncer urológico e inteligencia artificial aplicada a la urología. Excluimos artículos con falta de una metodología adecuada y escritos en cualquier idioma diferente al inglés. En total, 126 artículos de interés fueron encontrados, y, de estos seleccionamos 65 artículos que reportaban tratamientos novedosos para neoplasias urológicas, discutían medicina de precisión y perfiles de expresión genómica y bio-marcadores en urología, algoritmos de aprendizaje profundo, aprendizaje de máquina, y el uso de inteligencia artificial en la práctica urológica. Se hizo una revisión crítica de la literatura que se presenta en este artículo. La urología es una especialidad constantemente en cambio, con un gran rango de avances terapéuticos, un gran conocimiento de los perfiles de expresión genómica para cada cáncer urológico, y una tendencia a utilizar tecnología de punta para estudiar y tratar a nuestros pacientes. Todos estos desarrollos se deben analizar objetivamente, y hay que tener en cuenta los costos al sistema de salud, los riesgos y beneficios para los pacientes, y el contexto legal que implica cada uno. Hasta la fecha, estos avances tecnológicos y farmacológicos se deben analizar con cautela antes de vernos en la posición de cambiar nuestra práctica clínica. Se debe fortalecer la investigación médica para mejorar los resultados en el tratamiento y abordaje de nuestros pacientes.

Current state and outlook for drug repositioning anticipated in the field of ovarian cancer / 부인종양

Ovarian cancer is the seventh most common cancer and the eighth most common cause of cancer mortality in women. Although standard chemotherapy is the established treatment for ovarian cancer, the prognosis remains poor, and it is highly anticipated that new drugs will be developed. New drugs, such as humanized anti-vascular endothelial growth factor monoclonal antibodies and poly ADP-ribose polymerase inhibitors, are expected to improve clinical outcomes of ovarian cancer. However, long-term, costly research is required to develop such new drugs, and soaring national healthcare costs are becoming a concern worldwide. In this social context, drug repositioning, wherein existing drugs are used to develop drugs with new indications for other diseases, has recently gained attention. Because trials have already confirmed the safety in humans and the pharmacokinetics of such drugs, the development period is shorter than the conventional development of a new drug, thereby reducing costs. This review discusses the available basic experimental and clinical data on drugs used for other types of cancer for which drug repositioning is anticipated to repurpose the drug for the treatment of ovarian cancer. These include statins, which are used to treat dyslipidemia; bisphosphonate, which is used to treat osteoporosis; metformin, which is used to treat diabetes; non-steroidal anti-inflammatory drugs; ivermectin, an antiparasitic agent; and itraconazole, an anti-fungal agent. These drugs will play an important role in future drug repositioning strategies for ovarian cancer. Furthermore, drug repositioning is anticipated to extend not only to ovarian cancer treatment but also to ovarian cancer prevention.

Protective effects of perilla oil and alpha linolenic acid on SH-SY5Y neuronal cell death induced by hydrogen peroxide

BACKGROUND/OBJECTIVE: Oxidative stress plays a key role in neuronal cell damage, which is associated with neurodegenerative disease. The aim of present study was to investigate the neuroprotective effects of perilla oil (PO) and its active component, alpha-linolenic acid (ALA), against hydrogen peroxide (H₂O₂)-induced oxidative stress in SH-SY5Y neuronal cells. MATERIALS/METHODS: The SH-SY5Y human neuroblastoma cells exposed to 250 µM H₂O₂ for 24 h were treated with different concentrations of PO (25, 125, 250 and 500 µg/mL) and its major fatty acid, ALA (1, 2.5, 5 and 25 µ/mL). We examined the effects of PO and ALA on H₂O₂-induced cell viability, lactate dehydrogenase (LDH) release, and nuclear condensation. Moreover, we determined whether PO and ALA regulated the apoptosis-related protein expressions, such as cleaved-poly ADP ribose polymerase (PARP), cleaved caspase-9 and -3, BCL-2 and BAX. RESULTS: Treatment of H₂O₂ resulted in decreased cell viability, increased LDH release, and increase in the nuclei condensation as indicated by Hoechst 33342 staining. However, PO and ALA treatment significantly attenuated the neuronal cell death, indicating that PO and ALA potently blocked the H₂O₂-induced neuronal apoptosis. Furthermore, cleaved-PARP, cleaved caspase-9 and -3 activations were significantly decreased in the presence of PO and ALA, and the H₂O₂-mediated up-regulated BAX/BCL-2 ratio was blocked after treatment with PO and ALA. CONCLUSIONS: PO and its main fatty acid, ALA, exerted the protective activity from neuronal oxidative stress induced by H₂O₂. They regulated apoptotic pathway in neuronal cell death by alleviation of BAX/BCL-2 ratio, and down-regulation of cleaved-PARP and cleaved caspase-9 and -3. Although further studies are required to verify the protective mechanisms of PO and ALA from neuronal damage, PO and ALA are the promising agent against oxidative stress-induced apoptotic neuronal cell death.

Amygdalin Regulates Apoptosis and Adhesion in Hs578T Triple-Negative Breast Cancer Cells

Amygdalin, D-mandelonitrile-beta-D-glucoside-6-beta-glucoside, belongs to aromatic cyanogenic glycoside group derived from rosaceous plant seed. Mounting evidence has supported the anti-cancer effects of amygdalin. However, whether amygdalin indeed acts as an anti-tumor agent against breast cancer cells is not clear. The present study aimed to investigate the effect of amygdalin on the proliferation of human breast cancer cells. Here, we show that amygdalin exerted cytotoxic activities on estrogen receptors (ER)-positive MCF7 cells, and MDA-MB-231 and Hs578T triple-negative breast cancer (TNBC) cells. Amygdalin induced apoptosis of Hs578T TNBC cells. Amygdalin downregulated B-cell lymphoma 2 (Bcl-2), upregulated Bcl-2-associated X protein (Bax), activated of caspase-3 and cleaved poly ADP-ribose polymerase (PARP). Amygdalin activated a pro-apoptotic signaling molecule p38 mitogen-activated protein kinases (p38 MAPK) in Hs578T cells. Treatment of amygdalin significantly inhibited the adhesion of Hs578T cells, in which integrin alpha5 may be involved. Taken together, this study demonstrates that amygdalin induces apoptosis and inhibits adhesion of breast cancer cells. The results suggest a potential application of amygdalin as a chemopreventive agent to prevent or alleviate progression of breast cancer, especially TNBC.

TRPM2: a multifunctional ion channel for oxidative stress sensing / 生理学报

Transient receptor potential (TRP) superfamily is a superfamily of cation channels that can be divided into seven subfamilies. TRPM2 is the second member of the TRPM subfamily, which includes eight members, namely TRPM1-8. TRPM2 is widely expressed in excitable and non-excitable cells, where it forms a Ca(2+)-permeable cation channel and performs diverse cellular functions. TRPM2 channels are activated by ADP-ribose (ADPR), Ca(2+), H2O2 and other reactive oxygen species (ROS). It is established that TRPM2 serves as a cellular sensor for oxidative stress, mediating oxidative stress-induced [Ca(2+)]i increase and contributing to pathological processes in many cell types. Accumulating evidence has indicated that TRPM2 is a potential therapeutic target for oxidative stress-related diseases. This review will highlight recent progress in this field.

A Nudix Hydrolase Protein, Ysa1, Regulates Oxidative Stress Response and Antifungal Drug Susceptibility in Cryptococcus neoformans

A nucleoside diphosphate-linked moiety X (Nudix) hydrolase-like gene, YSA1, has been identified as one of the gromwell plant extract-responsive genes in Cryptococcus neoformans. Ysa1 is known to control intracellular concentrations of ADP-ribose or O-acetyl-ADP-ribose, and has diverse biological functions, including the response to oxidative stress in the ascomycete yeast, Saccharomyces cerevisiae. In this study, we characterized the role of YSA1 in the stress response and adaptation of the basidiomycete yeast, C. neoformans. We constructed three independent deletion mutants for YSA1, and analyzed their mutant phenotypes. We found that ysa1 mutants did not show increased sensitivity to reactive oxygen species-producing oxidative damage agents, such as hydrogen peroxide and menadione, but exhibited increased sensitivity to diamide, which is a thiol-specific oxidant. Ysa1 was dispensable for the response to most environmental stresses, such as genotoxic, osmotic, and endoplasmic reticulum stress. In conclusion, modulation of YSA1 may regulate the cellular response and adaptation of C. neoformans to certain oxidative stresses and contribute to the evolution of antifungal drug resistance.

Synergistic Effect of COX-2 Inhibitor on Paclitaxel-Induced Apoptosis in the Human Ovarian Cancer Cell Line OVCAR-3 / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Celecoxib, a highly selective cyclooxygenase-2 inhibitor, regulates apoptosis of several types of human cancer cells. The purpose of this study was to investigate whether celecoxib in combination with paclitaxel modulates apoptosis of ovarian cancer cells, and to identify the signal pathway by which celecoxib mediates apoptosis. MATERIALS AND METHODS: OVCAR-3 cells were exposed to paclitaxel (20 microM) in the absence or presence of celecoxib (10 microM). Cell viability was evaluated using a Cell Counting Kit-8 assay. Apoptosis was evaluated using Annexin-V/7-aminoactinomycin D staining and a cellular DNA fragmentation enzyme-linked immunosorbent assay. Caspase-3, -9, and cleavage of poly ADP-ribose polymerase (PARP) were determined by western blotting. Expression of nuclear factor-kappaB (NF-kappaB) and vascular endothelial growth factor (VEGF) and Akt activation were assessed using reverse transcriptase-polymerase chain reaction and western blotting. RESULTS: Celecoxib enhanced paclitaxel-induced growth inhibition of OVCAR-3 cells. Celecoxib significantly increased paclitaxel-induced apoptosis of OVCAR-3 cells. Pretreatment with celecoxib also increased activation of caspase-9, -3 and cleaved PARP following paclitaxel-treatment. Exposure of OVCAR-3 cells to celecoxib in combination with paclitaxel resulted in downregulation of NF-kappaB activation and VEGF expression. Furthermore, combining celecoxib and paclitaxel inhibited phosphorylation of Akt. CONCLUSION: OVCAR-3 cells were sensitized to paclitaxel-induced apoptosis by celecoxib through downregulation of NF-kappaB and Akt activation, suggesting that celecoxib may work synergistically with paclitaxel to inhibit different targets and ultimately produce anticancer effects. Combining celecoxib with paclitaxel may prove beneficial in the clinical treatment of ovarian cancer.

Synergistic Effect of COX-2 Inhibitor on Paclitaxel-Induced Apoptosis in the Human Ovarian Cancer Cell Line OVCAR-3 / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Celecoxib, a highly selective cyclooxygenase-2 inhibitor, regulates apoptosis of several types of human cancer cells. The purpose of this study was to investigate whether celecoxib in combination with paclitaxel modulates apoptosis of ovarian cancer cells, and to identify the signal pathway by which celecoxib mediates apoptosis. MATERIALS AND METHODS: OVCAR-3 cells were exposed to paclitaxel (20 microM) in the absence or presence of celecoxib (10 microM). Cell viability was evaluated using a Cell Counting Kit-8 assay. Apoptosis was evaluated using Annexin-V/7-aminoactinomycin D staining and a cellular DNA fragmentation enzyme-linked immunosorbent assay. Caspase-3, -9, and cleavage of poly ADP-ribose polymerase (PARP) were determined by western blotting. Expression of nuclear factor-kappaB (NF-kappaB) and vascular endothelial growth factor (VEGF) and Akt activation were assessed using reverse transcriptase-polymerase chain reaction and western blotting. RESULTS: Celecoxib enhanced paclitaxel-induced growth inhibition of OVCAR-3 cells. Celecoxib significantly increased paclitaxel-induced apoptosis of OVCAR-3 cells. Pretreatment with celecoxib also increased activation of caspase-9, -3 and cleaved PARP following paclitaxel-treatment. Exposure of OVCAR-3 cells to celecoxib in combination with paclitaxel resulted in downregulation of NF-kappaB activation and VEGF expression. Furthermore, combining celecoxib and paclitaxel inhibited phosphorylation of Akt. CONCLUSION: OVCAR-3 cells were sensitized to paclitaxel-induced apoptosis by celecoxib through downregulation of NF-kappaB and Akt activation, suggesting that celecoxib may work synergistically with paclitaxel to inhibit different targets and ultimately produce anticancer effects. Combining celecoxib with paclitaxel may prove beneficial in the clinical treatment of ovarian cancer.

Scant Extracellular NAD Cleaving Activity of Human Neutrophils is Down-Regulated by fMLP via FPRL1

Extracellular nicotinamide adenine dinucleotide (NAD) cleaving activity of a particular cell type determines the rate of the degradation of extracellular NAD with formation of metabolites in the vicinity of the plasma membrane, which has important physiological consequences. It is yet to be elucidated whether intact human neutrophils have any extracellular NAD cleaving activity. In this study, with a simple fluorometric assay utilizing 1,N6-ethenoadenine dinucleotide (etheno-NAD) as the substrate, we have shown that intact peripheral human neutrophils have scant extracellular etheno-NAD cleaving activity, which is much less than that of mouse bone marrow neutrophils, mouse peripheral neutrophils, human monocytes and lymphocytes. With high performance liquid chromatography (HPLC), we have identified that ADP-ribose (ADPR) is the major extracellular metabolite of NAD degradation by intact human neutrophils. The scant extracellular etheno-NAD cleaving activity is decreased further by N-formyl-methionine-leucine-phenylalanine (fMLP), a chemoattractant for neutrophils. The fMLP-mediated decrease in the extracellular etheno-NAD cleaving activity is reversed by WRW4, a potent FPRL1 antagonist. These findings show that a much less extracellular etheno-NAD cleaving activity of intact human neutrophils compared to other immune cell types is down-regulated by fMLP via a low affinity fMLP receptor FPRL1.

Cloning, expression and partial characterization of the C. elegans EEED8.8 gene product, a specific ADP-ribose diphosphatase, member of nudix hydrolase family

The C Elegans homologue of the human YSA1 protein, EEED and 8.8 [Nudix6], has been expressed as a thioredoxin fusion protein in Escherichia coli. It is an ADP-sugar pyrophosphatase with similar activities towards ADP-ribose and IDP-ribose. It is a specific ADP-ribose [adenosine 5-diphosphoribose] pyrophosphatase with no activities towards other nucleotides. The products of ADP-ribose hydrolysis were AMP and ribose 5-phosphate. Km and k[cat] values with ADP-ribose were 143.8 +/- 35.69 microm and18.9 +/- 2.485 micromol/min per mg protein using ADP-ribose as substrate respectively. The optimal activity was at pH 7.2 with 10 mM Mg[2+], fluoride was inhibitory, with an IC[50] of 40 microM. A major proposed function of the MutT motif proteins is to eliminate toxic nucleotide metabolites from the cell

Mycophenolic acid mediated mitochondrial membrane potential transition change lead to T lymphocyte apoptosis / 대한외과학회지

PURPOSE: This study demonstrated that apoptosis induced by mycophenolic acid (MPA) is mediated by mitochondrial membrane potential transition (MPT) changes in Jurkat cells. METHODS: Cell viability and MPT changes were measured by flow cytometry. Western blotting was performed to evaluate the expression of Bcl-2 family proteins, Bid, truncated Bid (tBid), cytochrome c, voltage dependent anion channel (VDAC), poly ADP-ribose polymerase (PARP), and protein kinase C-delta (PKC-delta). The catalytic activity of caspase-9 and -3 was also measured. RESULTS: Cell viability was decreased in time- and dose-dependent manners. Bcl-2 protein expression was decreased, but Bax protein expression was identified. A decreased Bcl-XL /Bcl-XS ratio was also noted. The expression of tBid protein also increased in a time-dependent manner in Jurkat cells treated with MPA. While normal MPT appeared as orange fluorescence, abnormal MPT corresponded to green fluorescence. Green fluorescence increased as orange decreased in the MPA-treated cells. Significantly increased concentrations of MPA induced the release of cytosolic cytochrome c. MPA also augmented the catalytic activity of caspase-9 and caspase-3 in Jurkat cells. Our findings demonstrated that MPA-induced apoptosis is mediated by MPT changes accompanied by decreased Bcl-XL expression and the appearance of tBid protein. The release of cytosolic cytochrome c from mitochondria and increased catalytic activity of caspase-9 and caspase-3 were observed in MPA-treated Jurkat cells. CONCLUSION: These results suggest that mitochondrial dysfunction caused by MPA induces human T lymphocyte apoptosis.

Endogenous ADP-ribosylation of eukaryotic elongation factor 2 and its 32 kDa tryptic fragment

Eukaryotic elongation factor 2 (eEF-2) can undergo ADP-ribosylation in the absence of diphtheria toxin. The binding of free ADP-ribose and endogenous transferase-dependent ADP-ribosylation were distinct reactions for eEF-2, as indicated by different findings. Incubation of eEF-2 tryptic fragment 32/33 kDa (32F) with NAD was ADP-ribosylated and gave rise to the covalent binding of ADP-ribose to eEF-2. 32F was revealed to be at the C-terminal by Edman degradation sequence analysis. In our study, the elution of 32F from SDS-PAGE was ADP-ribosylated both in the presence and absence of diphtheria toxin. These results suggest that endogenous ADP-ribosylation of 32F might be related to protein synthesis. This modification appears to be important for the cell function.

Effects of the Specific COX-2 Inhibitor, Celecoxib, on Paclitaxel-Induced Apoptosis in SK-OV-3 Epithelial Ovarian Cancer Cell Line / 대한산부인과학회지

OBJECTIVE: In vitro studies have revealed that treatment of various human cancer cell lines with specific cyclooxygenase 2 (COX-2) inhibitors induces apoptotic cell death. The goal of this article is to investigate the benefits of combining COX-2 inhibitors with existing treatment modalities in the management of ovarian cancer. METHODS: In this study we sought to determine the effects of combining paclitaxel and the COX-2 inhibitor celecoxib on apoptosis of epithelial ovarian cancer (EOC) cells. SK-OV-3 cells were exposed to increasing concentrations of paclitaxel (10(-7) M, 10(-6) M and 10(-5) M) and celecoxib (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M) as well as a combination of both drugs. The activity of apoptosis was evaluated by the morphologic examination and the MTT assay. The pattern of apoptosis was also assessed by the caspase-3 activity and the fraction of cleaved PARP (poly ADP-ribose polymerase) protein. RESULTS: Single application of both drugs could significantly increase the rate of apoptosis after 24 hours of continuous exposure. But concomitant treatment of SK-OV-3 EOC cell line with paclitaxel and celecoxib resulted in marked impairment of paclitaxel-induced apoptosis. The pattern of apoptosis induced by paclitaxel on SK-OV-3 EOC cell line was caspase-3 independent. CONCLUSION: Combining COX-2 inhibitors and paclitaxel does not have an additive or synergistic tumoricidal effect. On the contrary, celecoxib treatment markedly inhibited the apoptotic effects of paclitaxel in SK-OV-3 EOC cell line.

15-Lipoxygenase-1 Induced by Interleukin-4 Mediates Apoptosis in Oral Cavity Cancer Cells / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: In oral cavity cancer (OCC) cells, the effects of interleukin-4 (IL-4) are various according to the cell specificity. However, if IL-4 induces apoptosis on OCC cells, the mediator of this apoptosis is uncertain. Therefore, we investigated whether apoptosis of OCC cells occurs by IL-4 and whether 15-lipoxygenase-1 (15-LO-1) induced by IL-4 is the possible mediator of this apoptosis. MATERIALS AND METHODS: SCC 1483 cells were used. Flow cytometry and poly ADP-ribose polymerase cleavage were used to examine apoptosis. Western blot analysis and reverse transcription-polymerase chain reaction were used to measure 15-LO-1 protein and mRNA. RESULTS: The inhibition of cell proliferation by more than 50% was noted from 10 ng/ml of IL-4. At this dose, apoptosis was observed and this apoptosis was inhibited by 2.2 microM caffeic acid. 15-LO-1 expression was observed from the 8 hour treatment of IL-4 and apoptosis increased after the 24 hour treatment of IL-4. In this apoptosis, caspase cascade, cyclooxygenase-2, and non-steroidal anti-inflammatory drugs-activated gene-1 (NAG-1) were not involved. CONCLUSION: IL-4 induced apoptosis in SCC 1483 OCC cells and 15-LO-1 induced by IL-4 may mediate this apoptotic pathway.

In Vitro Responses of SK-OV-3 Ovarian Cancer Cell Lines to Tamoxifen and Celecoxib / 대한산부인과학회지

OBJECTIVE: There are some evidences that some epithelial ovarian cancer cells respond to hormonal therapy. And in vitro studies have revealed that treatment of various human cancer cell lines with selective cyclooxygenase 2 (COX-2) inhibitors induces apoptotic cell death. The goal of this article is to evaluate the effects of tamoxifen and celecoxib, a selective COX-2 inhibitor, on the ovarian cancer cells and the benefits of combining these agents in the management of ovarian cancer. METHODS: SK-OV-3 epithelial ovarian cancer cells were exposed to increasing concentration of tamoxifen (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M) and celecoxib (10(-8) M, 10(-7) M, 10(-6) M, 10(-5) M and 10(-4) M) as well as a combination of both drugs. The activity of apoptosis was evaluated by the morphologic examination and the MTT assay. The pattern of apoptosis was also assessed by the caspase-3 activity and the fraction of cleaved PARP (poly ADP-ribose polymerase) protein. RESULTS: Single application of both drugs could significantly increase the rate of apoptosis after 24 h of continuous exposure. Concomitant treatment of SK-OV-3 cells with tamoxifen and celecoxib induced significant increase in apoptosis, comparing with single drug exposure. The pattern of apoptosis induced by these agents on SK-OV-3 cells seemed to be caspase-3 dependent. CONCLUSION: Our data suggest that combining tamoxifen with selective COX-2 inhibitor seems to have at least an additive tumoricidal effect. A more definitive role for this combination therapy in clinical settings in ovarian cancer will need to be defined through the conduct of clinical trials.

Effect of Nitric Oxide on ADP-ribose Pyrophosphatase Activity

BACKGROUND: ADP-ribosyl pyrophosphatases (ADPRase) has been known to catalyze the hydrolysis of ADP-ribose to ribose-5-phosphate and AMP. The role of ADPRase has been suggested to sanitize the cell by removing potentially toxic ADP-ribose. In this study, we examined the effect of nitric oxide on ADPRase activity in macrophages. METHODS: ADPRase activity was measured in NO-inducing J774 cells. For in vitro experiments, recombinant human ADPRase was prepared in bacteria. RESULTS: ADPRase activity was increased by the treatment of exogenous NO generating reagent, sodium nitroprusside (SNP), in J774 cells. The increased ADPRase activity was mediated by the post-translational modification, likely to cause cADP-ribosylation via nitrosylation of cysteine residue on the enzyme. The stimulation with endogeneous NO inducers, TNF-alpha/IFN-gamma, also increased ADPRase activity through NO synthesis. Futhermore, ADPRase activity may be mediated by the post-translational modification of ADPRase, ADP-ribosylation. CONCLUSION: These results indicate that NO synthesized by macrophage activation plays a critical role in the increase in ADPRase activity following ADP-ribose metabolism.

Enzymatic characterization of Mycobacterium smegmatis ADP-ribosyltransferase

ADP-ribosyltransferase (ADPRT) catalyzes the reaction in which the ADP-ribose moiety of beta-NAD+ is transferred to specific amino acid residues in target proteins. The ADPRT of Mycobacterium smegmatis has been known to inactivate rifampin through ADP-ribosylation. However, the enzymatic characteristics and functions of the enzyme have not been elucidated yet. In this study, the ADPRT-glutathione S-transferase (GST) fusion protein was expressed in Escherichia coli and enzymatic characteristics of the fusion protein were investigated. ADPRT-GST fusion protein was an ADPribosyltransferase that had no NAD glycohydrolase activity. ADPRT-GST fusion protein showed no self-inactivation phenomenon that is a universal nature for all NAD glycohydrolases and is important in regulating its activity. ADPRT activity of the enzyme was decreased by novobiocin and isonicotinic acid hydrazide. These results suggest that Mycobacterium smegmatis ADPRT could be regulated by a different way from other NADases and involved in bacterial physiological process through a post-translational modification of cytosolic proteins.

Interactions between intracellular Ca2+ stores: Ca2+ released from the NAADP pool potentiates cADPR-induced Ca2+ release

Cells possess multiple intracellular Ca2+-releasing systems. Sea urchin egg homogenates are a well-established model to study intracellular Ca2+ release. In the present study the mechanism of interaction between three intracellular Ca2+ pools, namely the nicotinic acid adenine dinucleotide phosphate (NAADP), the cyclic ADP-ribose (cADPR) and the inositol 1',4',5'-trisphosphate (IP3)-regulated Ca2+ stores, is explored. The data indicate that the NAADP Ca2+ pool could be used to sensitize the cADPR system. In contrast, the IP3 pool was not affected by the Ca2+ released by NAADP. The mechanism of potentiation of the cADPR-induced Ca2+ release, promoted by Ca2+ released from the NAADP pool, is mediated by the mechanism of Ca2+-induced Ca2+ release. These data raise the possibility that the NAADP Ca2+ store may have a role as a regulator of the cellular sensitivity to cADPR

Poly-ADP-ribosylation of histone proteins of human kidney T1-cells in vitro following gamma-irradiation.

Poly-ADP-ribosylation of cellular proteins is involved with radiation induced damage and its repair. It has been observed that suspension of human kidney T1-cells in vitro attained elevated levels of poly-ADP-ribosylation due to experimental manipulations necessary for preparation of single cell suspension from monolayer cell cultures. These cells in suspension were exposed to various doses of gamma-rays with or without subsequent repair incubation. The PADPR of histones H3, H1 and H2B increased with increasing dose of radiation and decreased after 90 min or repair incubation. Concomitant with these changes, the affinity of histones to DNA in chromatin reduced immediately after irradiation. Normal affinity was reestablished after post-irradiation repair incubation. The results indicate that induction of poly-ADP-ribosylation of histone proteins by radiation and by manipulations to prepare single cell suspension involved different cellular components.