Role of DNMT3a in Hydroquinone-Induced Hematopoietic Stem Cell Toxicity / 中国实验血液学杂志

OBJECTIVE@#To investigate the regulatory effect and mechanism of DNA methyltransferase 3A (DNMT3a) in hydroquinone-induced hematopoietic stem cell toxicity.@*METHODS@#Cells (HSPC-1) were divided into 4 groups, that is A: normal HSPC-1; B: HQ-intervented HSPC-1; C: group B + pcDNA3 empty vector; D: group B + pcDNA3- DNMT3a. RT-qPCR and Western blot were used to detect the expression levels of DNMT3a and PARP-1 mRNA and protein, respectively. Cell morphology was observe; Cell viability and apoptosis rate of HSPC-1 were detected by MTT and flow cytometry, respectively.@*RESULTS@#Compared with group A, the expression levels of DNMT3a mRNA and protein in HSPC-1 of group B were decreased, while PARP-1 mRNA and protein were increased (P<0.05); there was no significant difference in the above indexes between group C and group B; compared with group B, the expression levels of DNMT3a mRNA and protein showed increased, while PARP-1 mRNA and protein were decreased significantly in cells of group D transfected with DNMT3a (P<0.05). Cells in each group were transfected with DNMT3a and cultured for 24 h, HSPC-1 in group A showed high density growth and mononuclear fusion growth, while the number of HSPC-1 in group B and C decreased and grew slowly. Compared with group B and C, the cell growth rate of group D was accelerated. The MTT analysis showed that cell viability of HSPC-1 in group B were lower than that of group A at 24 h, 48 h and 72 h (P<0.05); after transfected with DNMT3a, the cell viability of HSPC-1 in group D were higher than that of group B at 24 h, 48 h and 72 h (P<0.05). The apoptosis rate of cells in group B was significantly higher than that of group A (P<0.001), while the apoptosis rate in group D was lower than that of group B (P<0.001).@*CONCLUSION@#DNMT3a may be involved in the damage of hematopoietic stem cells induced by hydroquinone, which may be related to the regulation of PARP-1 activity by hydroquinone-inhibited DNMT3a.

AIF, PARP-1 and MicroRNA-9 expression in cerebral ischemia associated to alcoholism experimental model / Expresión de AIF, PARP-1 y MicroRNA-9 de isquemia cerebral asociado a un modelo experimental de alcoholismo

The chronic consumption of alcohol causes a worsening of the events that follow the cerebral ischemia. These events are regulated through the expression of several genes and microRNAs. The aimof this work was To analyze and describe the expression profile of PARP and AIF and miRNA-9 proteins in rats submitted to focal cerebral ischemia, associated or not with chronic alcoholism model. Methods: Twenty adult Wistar rats, subdivided into: control; ischemic; alcoholic and ischemic / alcoholized for immunohistochemical analysis and miRNA-9 gene expression. Results: There was a reduction in the protein expression of PARP-1 and a positive marking for AIF in the ischemic / alcoholized group. The miRNA-9 did not obtain significant expression. The association of ischemia with chronic alcohol use promoted a tendency to low expression of miRNA-9, low expression of PARP-1 and high expression of AIF, indicating an interference in the protective effect of miRNA-9 be observed in the other groups.

El consumo crónico de alcohol provoca un empeoramiento de los eventos que siguen a la isquemia cerebral. Estos eventos están regulados a través de la expresión de varios genes y microRNA. El objetivo de este trabajo fue analizar y describir el perfil de expresión de las proteínas PARP y AIF y microRNA-9 en ratas sometidas a isquemia cerebral focal, asociadas o no, con el modelo de alcoholismo crónico. Veinte ratas Wistar adultas se dividieron en: grupo control, isquémico alcohólico, e isquémico / alcoholizado para análisis inmunohistoquímico y expresión de genes microRNA-9. Resultados: Hubo una reducción en la expresión de proteínas de PARP-1 y un marcado positivo para AIF en el grupo isquémico / alcoholizado. No se observó una expresión significativa en el microRNA-9. La asociación de la isquemia con el consumo crónico de alcohol promovió una tendencia a la baja expresión de microRNA-9, baja expresión de PARP1 y alta expresión de AIF, lo que indica una interferencia en el efecto protector de microRNA-9 en los otros grupos.

Biodentine Induce Proteínas Apoptóticas Caspasa 3 y PARP-1 en Células de la Pulpa Dental Humana / Biodentine Induces Apoptotic Proteins Caspase 3 and PARP - 1 on Human Dental Pulp Cells

RESUMEN: Las patologías pulpares han sido un verdadero reto para la odontología principalmente por su tratamiento. Actualmente, existen numerosos biomateriales en el mercado que reportan tener propiedades inherentes en los tejidos dentarios. Sin embargo, diferentes estudios sobre múltiples líneas celulares expuestas a estos biomateriales demuestran resultados controversiales como biocompatiblidad y citotoxicidad celular. Biodentine, es un cemento endodóntico en base a silicatos cálcico de múltiples aplicaciones, que prestaría propiedades de biocompatibilidad como bioactividad celular, características que le permitirían incluso ser utilizado en contacto directo con la pulpa dental. El objetivo de este estudio es la evaluación in-vitro de Biodentine, sobre cultivos de células de la pulpa dental humana (CCPDH). Se prepararon discos de cemento de Biodentine™ de 2 x 6 mm, los que se expusieron a cultivos de células aisladas de la pulpa dental humana. Luego de 24, 48 y 72 horas de exposición, se realizaron ensayos de viabilidad celular utilizando el método colorimétrico MTT. También se realizaron ensayos de expresión proteica de dos proteínas involucradas en la vía de señalización de la apoptosis celular: Caspasa - 3 clivada y Poli (ADP-Ribosa) Polimerasa, PARP - 1. Existen diferencias estadísticamente significativas (p<0,05) en los ensayos de viabilidad celular entre las células expuestas a Biodentine y el grupo control, como también a medida que aumenta el tiempo de exposición (p<0,05). Por otra parte, también existen diferencias significativas (p<0,05) en la expresión de PARP- 1 en los grupos sometidos a Biodentine. Los resultados obtenidos en este estudio demuestran que Biodentine genera citotoxicidad celular en cultivos celulares de pulpa dental humana, por disminución de la viabilidad celular como por la expresión de proteínas apoptóticas. Es por esto que la utilización de este biomaterial debería ser estudiado y considerarse en cada caso clínico, especialmente como recubridor pulpar directo.

ABSTRACT: Oral pathologies have been a real challenge for dentistry, mainly due to its treatment. Currently, there are numerous biomaterials on the market that may present inherent properties in dental tissues. However, studies on multiple cell lines are based on biocompatible results such as biocompatibility and cellular cytotoxicity. Biodentine is endodontic cement based on calcium silicates of multiple applications, which would provide biocompatibility properties as cellular bioactivity, characteristics that will allow it to be used in direct contact with the dental pulp. The objective of this study is the in vitro evaluation of Biodentine, on cultures of cells of the human dental pulp (HDPC). Biodentine cement disks of 2 x 6 mm were prepared, and HDPC culture plates were introduced. After 24, 48 and 72 hours of exposure, cell viability tests were performed using the MTT colorimetric method. On the other hand, protein expression assays of two proteins involved in the signaling pathway of cell apoptosis Caspase-3 cleaved (cas-3 clv) and PARP-1 are carried out. There are statistically significant differences (p <0,05) in the cell viability tests between Biodentine and control group, as well as the exposure time increases (p <0,05). Otherwise, there are also significant differences (p <0,05) in the expression of PARP-1 in the groups, sometimes a Biodentine. The results in this study that Biodentine generates a cellular cytotoxicity in HDPC cultures, therefore, cell viability as the expression of apoptotic proteins. This is why the use of this biomaterial should be studied for each particular clinical case, especially as a direct pulp capping agent.

Neuroprotective effects and mechanism of ethanol extract of Cistanche tubulosa against oxygen-glucose deprivation/reperfusion / 中国中药杂志

To investigate the inhibitory effects and mechanism of Cistanche tubulosa ethanol extract( CTEE) against oxygen-glucose deprivation/reperfusion( OGD/R)-induced PC12 cells neuronal injury. In this study,OGD/R-induced PC12 cells were used to explore the neuroprotective effects of CTEE( 12. 5,25,50 mg·L-1) by detecting cell viability with MTT assay,apoptosis with AO/EB and Hoechst 33258,mitochondrial membrane potential changes with JC-1 staining,mitochondrial oxidative stress with MitoSOX staining,as well as the apoptosis-related protein expression( PARP,cleaved PARP,caspase-3,cleaved caspase-3,Bax,Bcl-2) with Western blot. RESULTS:: showed that CTEE effectively protected OGD/R-induced neuronal injury and increased the survival rate of PC12 cells.AO/EB and Hoechst 33258 staining showed that CTEE could effectively inhibit apoptosis. Moreover,JC-1 and MitoSOX staining results showed that CTEE decreased mitochondrial stress and mitochondrial membrane potential imbalance in PC12 cells in a concentration-dependent manner. Meanwhile,CTEE could obviously suppress the activation of key proteins in mitochondrial apoptosis pathway such as caspase-3 and PARP,and significantly inhibit the rise of Bax and down-regulation of Bcl-2. In conclusion,CTEE has obvious protective effects on OGD/R-induced PC12 cells neuronal injury,potentially via inhibiting mitochondrial oxidative stress and apoptosis-related signaling pathway.

Saponins isolated from Schizocapsa plantaginea inhibit human hepatocellular carcinoma cell growth in vivo and in vitro via mitogen-activated protein kinase signaling / 中国天然药物

The underground cane of Schizocapsa plantaginea (Hance) has long been used by Chinese ethnic minority as a constituent of anti-cancer formulae. Saponins are abundant secondary metabolic products located in the underground cane of this plant. The potential therapeutic effects of total saponins isolated from Schizocapsa plantaginea (Hance) (SSPH) on human hepatocellular carcinoma (HCC) were tested in vitro in human liver cancer cell lines, SMMC-7721 and Bel-7404. Apoptosis and cell cycle arrest were determined using flow cytometry, caspase activation was determined by ELISA, and PARP, cleaved PARP, mitogen-activated protein kinase (MAPK) expression and phosphorylation were measured using Western blotting analysis. In vivo anti-HCC effects of SSPH were verified in nude mouse xenograft model. SSPH exerted markedly inhibitory effect on HCC cell proliferation in time- and concentration-dependent manner. Moreover, SSPH significantly induced apoptosis through caspase-dependent signaling and arrested cell cycle at G/M phase. These anti-proliferation effects of SSPH were associated with up-regulated phosphorylation of extracellular signal-regulated kinase-1/2 (Erk1/2) and c-jun-NH2-kinase-1/2 (JNK1/2) and reduced phosphorylation of p38MAPK. Furthermore, inhibitors of ERK, UO126, and JNK, SP600125 inhibited the anti-proliferation effects by SSPH, suggesting that Erk and JNK were the effector molecules in SSPH induced anti-proliferative action. During in vivo experiments, SSPH was found to inhibit xenograft tumor growth in nude mice, with a similar mechanism in vitro. Our study confirmed that SSPH exerted antagonistic effects on human liver cancer cells both in vitro and in vivo. Molecular mechanisms underlying SSPH action might be closely associated with MAPK signaling pathways. These results indicated that SSPH has potential therapeutic effects on HCC.

Saponins isolated from Schizocapsa plantaginea inhibit human hepatocellular carcinoma cell growth in vivo and in vitro via mitogen-activated protein kinase signaling / 中国天然药物

The underground cane of Schizocapsa plantaginea (Hance) has long been used by Chinese ethnic minority as a constituent of anti-cancer formulae. Saponins are abundant secondary metabolic products located in the underground cane of this plant. The potential therapeutic effects of total saponins isolated from Schizocapsa plantaginea (Hance) (SSPH) on human hepatocellular carcinoma (HCC) were tested in vitro in human liver cancer cell lines, SMMC-7721 and Bel-7404. Apoptosis and cell cycle arrest were determined using flow cytometry, caspase activation was determined by ELISA, and PARP, cleaved PARP, mitogen-activated protein kinase (MAPK) expression and phosphorylation were measured using Western blotting analysis. In vivo anti-HCC effects of SSPH were verified in nude mouse xenograft model. SSPH exerted markedly inhibitory effect on HCC cell proliferation in time- and concentration-dependent manner. Moreover, SSPH significantly induced apoptosis through caspase-dependent signaling and arrested cell cycle at G/M phase. These anti-proliferation effects of SSPH were associated with up-regulated phosphorylation of extracellular signal-regulated kinase-1/2 (Erk1/2) and c-jun-NH2-kinase-1/2 (JNK1/2) and reduced phosphorylation of p38MAPK. Furthermore, inhibitors of ERK, UO126, and JNK, SP600125 inhibited the anti-proliferation effects by SSPH, suggesting that Erk and JNK were the effector molecules in SSPH induced anti-proliferative action. During in vivo experiments, SSPH was found to inhibit xenograft tumor growth in nude mice, with a similar mechanism in vitro. Our study confirmed that SSPH exerted antagonistic effects on human liver cancer cells both in vitro and in vivo. Molecular mechanisms underlying SSPH action might be closely associated with MAPK signaling pathways. These results indicated that SSPH has potential therapeutic effects on HCC.

Carcinomas de ovário associados à endometriose: expressão de marcadores proteicos de terapia alvo e prognóstico / Endometriosis-associated ovarian carcinomas: expression of protein biomarkers associated to target therapies and prognosis

Resumo: Introdução: endometriose é uma doença benigna, capaz de progredir extensamente e gerar clones atípicos. Considerada precursora dos carcinomas de células claras (CCOC) e endometrióide (EOC) de ovário, atualmente chamados carcinomas de ovário associados à endometriose (EAOC). Objetivos: comparar o perfil epidemiológico, a associação com endometriose e a expressão de marcadores imuno-histoquímicos para ARID1A, VEGF, PD-L1 e PARP-1 em mulheres com CCOC e EOC, e sua correlação com a sobrevida livre de progressão (SLP) e sobrevida global (SG). Métodos: estudo de coorte reconstituída, com 50 casos incluídos de CCOC e EOC tratados no CAISM-UNICAMP entre 1995 até 2016, acompanhados até 02/2017. Microarranjos de tecido com amostras de CCOC, EOC e endometriose foram corados com anticorpos monoclonais contra ARID1A, e para os biomarcadores proteicos VEGF, PD-L1, PARP-1 através de imuno-histoquímica. A expressão de ARID1A foi classificada (0 a 100) conforme a porcentagem de células não coradas. A expressão de VEGF, PD-L1 e PARP-1 foi classificada (0 a 300) conforme a multiplicação da porcentagem de células coradas por um fator da intensidade de expressão (ausente=0; fraco=1; moderado=2; forte=3). Idade ao diagnóstico; menopausa; índice de massa corpórea (IMC); CA-125; diagnóstico de endometriose; datas do diagnóstico, da progressão, do óbito e da última consulta foram recuperados dos prontuários. Comparação entre grupos foi realizada através de testes T e de ?2. A SLP (diferença de tempo entre o diagnóstico e a data de progressão) e a SG (diferença de tempo entre o diagnóstico e o óbito ou data da última data de consulta) foi avaliada através de curvas de Kaplan-Meyer e teste de Log-Rank ou regressão de COX. Resultados: 23 mulheres com CCOC (46%), e 27 com EOC (54%) foram incluídas; 80% tinham endometriose associada, 42% eram nulíparas, 42% eram pré-menopausa e CA125 foi elevado em todos estádios (FIGO I-II= média 614.7Ui/mL; FIGO III-IV= media 2361.2Ui/mL). A média de idade ao diagnóstico foi 7 anos menor em mulheres com EOC do que naquelas com CCOC. O CCOC foi mais diagnosticado em estágios iniciais quando associado à endometriose (p=0,03). O prognóstico dos EOC e CCOC em estádios iniciais foi semelhante (p=0,96). Os CCOC não associado à endometriose tiveram menor SG (p=0,04). A expressão de todos os biomarcadores esteve presente nos EAOC e na endometriose. O aumento da expressão de VEGF entre endometriose e câncer foi significativo (p=0,0002). A hiperexpressão de PARP-1 correlacionou-se negativamente com a SLP (p=0,03) e SG (p=0,01) em estádios iniciais. Conclusão: Os CCOC e EOC são comumente diagnosticados em estádios iniciais (FIGO I-II= 68%) e estão frequentemente associados à endometriose (80% dos casos). Quando associados à endometriose, os CCOC foram mais diagnosticados em estádios iniciais e tiveram SG maior. Houve elevada porcentagem de células com ARID1A mutado nos EAOC (>40%). VEGF se expressou mais intensamente nos CCOC e EOC que na endometriose, já a expressão de PD-L1 e de PARP-1 foi similar. Apenas a hiperexpressão de PARP-1 reduziu significativamente a SLP e a SG nos CCOC e EOC nos estádios iniciais(AU)

Abstract: Introduction: Endometriosis is a benign disease, able to progress widely and generate atypical clones. It is a precursor of clear cell ovarian carcinomas (CCOC) and endometrioid ovarian carcinomas (EOCs), now called endometriosis-associated ovarian carcinomas (EAOC). Objectives: To compare the epidemiological profile, association with endometriosis and the expression of immunohistochemical markers for ARID1A, VEGF, PD-L1 and PARP-1 in women with CCOC and EOC, and its correlation with progression-free survival (PFS) and overall survival (OS). Methods: A reconstituted cohort study with 50 cases of CCOC and EOC included. Cases were treated at CAISM-UNICAMP between 1995 and 2016, followed up until 02/2017. Tissue microarrays with CCOC, EOC and endometriosis samples were stained with monoclonal antibodies against ARID1A, and for VEGF, PD-L1, PARP-1 biomarkers by immunohistochemistry. The expression of ARID1A was classified (0 to 100) according to the percentage of unstained cells. The expression of VEGF, PD-L1 and PARP-1 was classified (0 to 300) multiplying the percentage of stained cells by an intensity of expression factor (absent=0, weak=1, moderate=2, strong=3). Age at diagnosis; menopause; BMI (body mass index); CA-125 levels; diagnosis of endometriosis; date of diagnosis, date of progression, date of death and date of last consultation were retrieved from the medical records. Comparison between groups was performed through T and ?2 tests. The PFS (difference in time between diagnosis and progression date) and OS (difference in time between diagnosis and death or the last date of consultation) was assessed using Kaplan-Meyer curves and Log-Rank test or COX multivariate models. Results: twenty-three women with CCOC (46%), and 27 with EOC (54%) were included; 80% had associated endometriosis, 42% were nulliparous, 42% were premenopausal, and CA125 was elevated at all stages (FIGO I-II = mean 614.7Ui / mL; FIGO III-IV = mean 2361.2Ui / mL). The mean age at diagnosis was 7 years lower in women with EOC than in those with CCOC. CCOC when associated with endometriosis were more diagnosed at early stages (p=0.03). The prognosis of EOC and CCOC at early stages was similar (p=0.96). CCOCs not associated with endometriosis had shorter OS (p=0.04). Expression of all biomarkers was present in the EAOC and endometriosis. The increase in VEGF expression between endometriosis and cancer was significant (p=0.0002). The overexpression of PARP-1 correlated negatively with PFS (p=0.03) and OS (p=0.01) at FIGO I-II stages. Conclusion: The diagnosis of women with EOC was made earlier than in those with CCOC. CCOC and EOC are commonly diagnosed in early stages (FIGO I-II - 68%) and were associated with endometriosis (80% of cases). When associated with endometriosis, clear cell carcinomas are more likely diagnosed at early stages, and the association of endometriosis with CCOC improves OS. There was a high percentage of cells with mutated ARID1A gene in EAOC (> 40%). VEGF was expressed more intensely in CCOC and EOC than in endometriosis, whereas expression of PD-L1 and PARP-1 was similar. Only the overexpression of PARP-1 significantly reduced PFS and OS in CCOC and EOC at early stages(AU)

Homologous recombination deficiency in ovarian cancer: a review of its epidemiology and management

Ovarian cancer patients with homologous recombination deficiencies exhibit specific clinical behaviors, and improved responses to treatments, such as platinum-based chemotherapy and poly (ADP-ribose) polymerase (PARP) inhibitors, have been observed. Germline mutations in the BRCA 1/2 genes are the most well-known mechanisms of homologous recombination deficiency. However, other mechanisms, such as germline and somatic mutations in other homologous recombination genes and epigenetic modifications, have also been implicated in homologous recombination deficiency. The epidemiology and implications of these other mechanisms need to be better understood to improve the treatment strategies for these patients. Furthermore, an evaluation of various diagnostic tests to investigate homologous recombination deficiency is essential. Comprehension of the role of homologous recombination deficiency in ovarian cancer also allows the development of therapeutic combinations that can improve the efficacy of treatment. In this review, we discuss the epidemiology and management of homologous recombination deficiency in ovarian cancer patients.

Synergistic anti-tumor effect of obatoclax and MG-132 in esophageal cancer cell line CaES-17 / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore whether MG-132 could enhance the anti-tumor activity of obatoclax against esophageal cancer cell line CaES-17.</p><p><b>METHODS</b>MTT assay was used to determine the cytotoxicity of obatoclax and MG-132 in CaES-17 cells. The IC(50) of obatoclax and MG-132 were used to determine the molar ratio (1:2.4) of the two drugs for combined treatment of the cells. The concentrations of obatoclax and MG-132 ranged from 1/8 IC(50) to 4 IC(50) after serial dilution, and their combination index (CI) was calculated using CompuSyn software. The expression of ubiquitin and the cleavage of PARP, caspase-9, phospho-histone H3 and phospho-aurora A/B/C in the exposed cells were examined with Western blotting; the cell apoptosis was measured by flow cytometry with Annexin V staining, and the percentage of cells in each cell cycle phase was also determined by flow cytometry.</p><p><b>RESULTS</b>The CI of obatoclax and MG-132 was 0.296 for a 50% inhibition of Caes-17 cells and was 0.104 for a 95% inhibition. The cells treated with obatoclax or MG-132 alone showed increased expression of ubiquitin and cleavage of PARP and caspase-9. Compared with the cells treated with obatoclax or MG-132 alone, the cells with a combined treatment exhibited significantly increased expression of ubiquitin, cleavage of PARP and caspase-9, and expression of phospho-Histone H3 (P<0.05). The combined treatment of the cells also resulted in significantly increased expression of phospho-Aurora A/B/C compared with obatoclax treatment alone. The cells with the combined treatment showed significantly higher percentages of apoptotic cells and cells in sub-G(1) and G(2)/M phases compared with the cells treated with either of the drugs (P<0.05).</p><p><b>CONCLUSION</b>Obatoclax combined with MG-132 shows a significant synergistic anti-tumor effect against esophageal cancer CaES-17 cells by inducing apoptosis and cell cycle arrest.</p>

Poly(ADP-ribosyl)ation of Apoptosis Antagonizing Transcription Factor Involved in Hydroquinone-Induced DNA Damage Response / 生物医学与环境科学（英文）

The molecular mechanism of DNA damage induced by hydroquinone (HQ) remains unclear. Poly(ADP-ribose) polymerase-1 (PARP-1) usually works as a DNA damage sensor, and hence, it is possible that PARP-1 is involved in the DNA damage response induced by HQ. In TK6 cells treated with HQ, PARP activity as well as the expression of apoptosis antagonizing transcription factor (AATF), PARP-1, and phosphorylated H2AX (γ-H2AX) were maximum at 0.5 h, 6 h, 3 h, and 3 h, respectively. To explore the detailed mechanisms underlying the prompt DNA repair reaction, the above indicators were investigated in PARP-1-silenced cells. PARP activity and expression of AATF and PARP-1 decreased to 36%, 32%, and 33%, respectively, in the cells; however, γ-H2AX expression increased to 265%. Co-immunoprecipitation (co-IP) assays were employed to determine whether PARP-1 and AATF formed protein complexes. The interaction between these proteins together with the results from IP assays and confocal microscopy indicated that poly(ADP-ribosyl)ation (PARylation) regulated AATF expression. In conclusion, PARP-1 was involved in the DNA damage repair induced by HQ via increasing the accumulation of AATF through PARylation.

Mechanism of colon cancer cell apoptosis induced by telocinobufagin: role of oxidative stress and apoptosis pathway / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of telocinobufagin on viability and apoptosis of colorectal cancer (CRC) cells and explore the mechanism of telocinobufagin-induced apoptosis.</p><p><b>METHODS</b>MTT assay was performed to detect the viability of CRC cells exposed to telocinobufagin. Nuclear staining with Hoechst 33342 and flow cytometry were used to analyze the cell death of CRC cells. Expressions of proteins related with cell apoptosis and oxidative stress were determined with Western blotting.</p><p><b>RESULTS</b>Telocinobufagin decreased the viability of CRC cells in a time- and dose-dependent manner. The presence of karyopycnosis and apoptotic bodies together with the results of flow cytometry suggested that telocinobufagin induced cell apoptosis to cause cell death. Western blotting showed that telocinobufagin exposure of the cells resulted in upregulated p53 and Bax protein expressions and promoted cleavage of caspase 9 and PARP. Telocinobufagin induced phosphorylation of Bad and PARP cleavage, and suppressed phosphorylation of IKBα and TAK1 and expression of survivin in the cells.</p><p><b>CONCLUSION</b>Telocinobufagin can decrease the viability of CRC cells by inducing cell apoptosis, which involves p53-mediated Bax activation and inhibition of the IAP pathway.</p>

Influence of RNA interference on MSI-2 gene in THP-1 cell and expression of NUMB / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the effect of small interfering RNA（siRNA）for MSI-2 on the growth, apoptosis and NUMB expression of THP-1 cells.</p><p><b>METHODS</b>Three siRNA for MSI-2 gene was designed and transfected into THP- 1 cells. The cell inhibition, colony formation and apoptosis were determined. The protein expression of NUMB, caspase- 3 and PARP were detected by Western blotting.</p><p><b>RESULTS</b>After MSI- 2 expression of THP- 1 cells was down- regulated for 24 hours, cell inhibition of siRNA MSI-2 group was（47.89±7.64）%, obviously higher than that of negative control group（P=0.005）. After 9 days, cell colony count of siRNA MSI-2 group was 7.50±1.53, also lower than that of negative control group（35.75±7.46, P<0.001）. In addition, apoptotic rates of siRNA MSI- 2 group at 24 hours ［（15.22±1.52）%］and 48 hours［（33.83±3.96）%］were significantly higher than those of negative control group（P=0.008 and P=0.001, respectively）. Accordingly, activations of caspase-3 and PARP and increased NUMB were observed in siRNA MSI- 2 group.</p><p><b>CONCLUSION</b>siRNA for MSI- 2 gene could increase the expressions of NUMB to inhibit the proliferation and induce apoptosis of THP-1 cells.</p>

Effect of silicon dioxide nanoparticles on expression and DNA methylation of PARP-1 gene in HaCaT cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effect of silicon dioxide nanoparticles on the expression and promoter region CpG islands methylation of (Poly [ADP-ribose] polymerase 1, PARP-1) gene in human HaCaT Cell.</p><p><b>METHODS</b>HaCaT Cells were treated with nm-SiO₂at 0, 2.5, 5 and 10 µg/mL and micro-SiO₂at 10 µg/ml for 24 h and DAC treatment was given at 10 µg/ml group for 48 h. Real-time PCR and western blot assay was used to detect the expression of PARP-1 mRNA and protein. BSP (Bisulfite Pyrosequence, BSP) assay was used to detect the promoter region CpG islands methylation status of PARP-1 gene.</p><p><b>RESULTS</b>After exposure to nano-SiO₂particles, compared to CTRL group, the mRNA and protein expression of PARP-1 in micro-SiO₂and 2.5 µg/ml group unchanged, but he mRNA and protein expression of PARP-1 in 5, 10 µg/ml as well as DAC group was down-regulated and there are statistical significance between CTRL group and 5, 10 µg/ml as well as DAC group and the PARP-1 promoter region CpG islands showed methylation.</p><p><b>CONCLUSION</b>nano-SiO₂can down-regulate PARP-1 expression in HaCaT Cell and this is associated with the change in the methylation of PARP-1 gene promoter region CpG islands induced by nano-SiO₂particles.</p>

Effect of PARP1 inhibitor PJ34 on multi-drug resistance in human multiple myeloma cell line and its relationship with FA/BRCA pathway / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the effect of PARP1 inhibitor PJ34 on multi-drug resistance in a human multiple myeloma cell line and its connection with FA/BRCA pathway in DNA damage repair.</p><p><b>METHODS</b>A CCK8 assay was used to measure the inhibition rate. Real-time quantitative PCR was used to detect expression changes of DNA repair genes involved in the FA/BRCA pathway. Western blotting assay was used to detect expression of key protein FANCD2 in the FA/BRCA pathway. Annexin VFITC/PI double staining flow cytometry was used to measure cell apoptosis induced by PJ34. A COMET assay was used to detect the effect of PJ34 on DNA damage repair.</p><p><b>RESULTS</b>PJ34 could significantly enhance the sensitivity of RPMI8226/R cells to melphalan. The IC50 value of melphalan was dropped from 20.43 mol/L to 7.8 mol/L. PJ34 could inhibit the DNA damage repair, and the effect was related with the inhibition of FA/BRCA pathway. PJ34 and melphalan showed a synergistic effect in promoting the apoptosis of RPMI8226/R cells.</p><p><b>CONCLUSION</b>PJ34 can reverse the resistance of RPMI8226/R cells to melphalan by inhibiting the FA/BRCA pathway, which in turn can induce suppression of DNA damage repair. Therefore, PJ34 may have clinical value in overcoming the multi-drug resistance of multiple myeloma.</p>

Design, synthesis and biological evaluation of novel para-substituted 1-benzyl-quinazoline-2, 4 (1H, 3H)-diones as human PARP-1 inhibitors / 药学学报

Poly(ADP-ribose) polymerase-1 (PARP-1) has emerged as a promising anticancer drug target due to its key role in the DNA repair process. It can polymerize ADP-ribose units on its substrate proteins which are involved in the regulation of DNA repair. In this work, a novel series of para-substituted 1-benzyl-quinazoline-2, 4 (1H, 3H)-diones was designed and synthesized, and the inhibitory activities against PARP-1 of compounds 7a-7e, 8a-8f, 9a-9c and 10a-10c were evaluated. Of all the tested compounds, nine compounds displayed inhibitory activities with IC50 values ranging from 4.6 to 39.2 micromol x L(-1). In order to predict the binding modes of the potent molecules, molecular docking was performed using CDOCKER algorithm, and that will facilitate to further develop more potent PARP-1 inhibitors with a quinazolinedione scaffold.

Γ-secretase inhibitor DAPT prevents neuronal death and memory impairment in sepsis associated encephalopathy in septic rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Brain dysfunction is a frequent complication of sepsis, usually defined as sepsis-associated encephalopathy (SAE). Although the Notch signaling pathway has been proven to be involved in both ischemia and neuronal proliferation, its role in SAE is still unknown. Here, the effect of the Notch signaling pathway involved γ-secretase inhibitor DAPT on SAE in septic rats was investigated in a cecal ligation and puncture (CLP) model.</p><p><b>METHODS</b>Fifty-nine Sprague-Dawley rats were randomly divided into four groups, with the septic group receiving the CLP operation. Twenty-four hours after CLP or sham treatment, rats were sacrificed and their hippocampus was harvested for Western blot analysis. TNF-α expression was determined using an enzyme-linked immunosorbent assay (ELISA) kit. Neuronal apoptosis was assessed by TUNEL staining, and neuronal cell death was detected by H&E staining. Finally, a novel object recognition experiment was used to evaluate memory impairment.</p><p><b>RESULTS</b>Our data showed that sepsis can increase the expression of hippocampal Notch receptor intracellular domain (NICD) and poly (adenosine diphosphate [ADP]-ribose) polymerase-1 (PARP-1), as well as the inflammatory response, neuronal apoptosis, neuronal death, and memory dysfunction in rats. The γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-1-alanyl]-S-phenylglycine t-butyl ester (DAPT) can significantly decrease the level of NICD and PARP-1, reduce hippocampal neuronal apoptosis and death, attenuate TNF-α release and rescue cognitive impairment caused by CLP.</p><p><b>CONCLUSION</b>The neuroprotective effect of DAPT on neuronal death and memory impairment in septic rats, which could be a new therapeutic approach for treating SAE in the future.</p>

Effect of Actinidia chinensis planch polysaccharide on the growth and apoptosis, and p-p38 expression in human gastric cancer SGC-7901 cells / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate the effect of Actinidia chinensis Planch polysaccharide (ACPS) on the growth and apoptosis of human gastric cancer SGC-7901 cells, and to explore the effect of SGC-7901 cells on p-p38 expression.</p><p><b>METHODS</b>The inhibition rates at different concentrations of ACPS on SGC-7901 cells at 24, 48, and 72 h were detected using CCK-8 method. Apoptosis ratios in SGC-7901 were determined by flow cytometry after 48-h treatment of different concentrations of ACPS. The expression of pro-caspase-9, PARP, and p-p38 in SGC-7901 cells after treated by different concentrations of ACPS was detected using Western blot. The expression of pro-caspase-9, PARP, and p-p38 was detected after SGC-7901 cells were pre-treated by p38 specific inhibitor.</p><p><b>RESULTS</b>Compared with the control group, the optical density of SGC-7901 cells decreased after treated by 1, 2.5, 5, and 10 mg/mL ACPS (P < 0.05). Meanwhile, the longer the acting time, the lower the optic density (P < 0.01). IC50 was 7.43 mg/mL at 24 h; 3.88 mg/mL at 48 h, and 1.32 mg/mL at 72 h respectively. ACPS suppressed the protein expression of pro-caspase-9 (P < 0.01) and up-regulated the expression of PARP (89KD) (both P < 0.01). Further study showed that the protein expression of p-p38 was up-regulated in SGC-7901 cells treated by ACPS of different concentrations at 24 h (P < 0.05). The expression of phosphorylation p38 and the ACPS induced apoptosis of SGC-7901 cells could be inhibited after treated by specific inhibitor for 2 h.</p><p><b>CONCLUSIONS</b>ACPS could inhibit the growth of SGC-7901 cells and induce apoptosis. The underlying mechanism of inducing apoptosis was partially due to activating the p38MAPK path and further activating Caspase9 and PARP, finally leading to cell death.</p>

Role of PARP-1 in formaldehyde-induced DNA damage repair and apoptosis in human bronchial epithelial cells / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the role of poly (ADP-ribose) polymerase-l (PARP-1) in formaldehyde-induced DNA damage response in human bronchial epithelial (HBE) cells and to investigate the mechanism of formaldehyde carcinogenicity.</p><p><b>METHODS</b>The protein levels were measured by Western blot. The interaction between different proteins was determined by co-immunoprecipitation assay. The chemical inhibitor was used to confirm the relationship between PARP-1 and DNA damage repair.</p><p><b>RESULTS</b>After being exposed to different concentrations of formaldehyde for 4 h, HBE cells showed no significant changes in cell viability. Cell viability was significantly reduced after 24-h exposure to 80 and 160 µmol/L formaldehyde (P < 0.05). The 10 µmol/L formaldehyde resulted in significant increases in the protein levels of PARP-1 and XRCC-1. However, 80 µmol/L formaldehyde led to a significant decrease in the protein level of PARP-1 of 124 KD molecular weight but a significant increase in the protein level of PARP-1 of 89 KD molecular weight; there was no significant change in the protein level of XRCC-1. The co-immunoprecipitation assay showed that 10 µmol/L formaldehyde induced increased binding between PARP-1 and XRCC-1, but 80 µmol/L formaldehyde led to no significant change in binding between PARP-1 and XRCC-1. Here, we confirmed the role of 10 µmol/L formaldehyde in strand breaks by comet assay which showed an increase in the tail DNA content of HBE cells after 4-h formaldehyde exposure. No significant difference was observed in tail DNA content between treated HBE cells and control cells at 2 h after formaldehyde was removed. Moreover, compared with control, inhibition of PARP-1 induced a significant increase in tail DNA content, and a significant difference was observed in tail DNA content between inhibited HBE cells and control cells at 2 h after formaldehyde was removed. Inhibition of PARP-1 significantly reduced DNA repair capacity.</p><p><b>CONCLUSION</b>PARP-1 mediated the repair of DNA damage induced by low-concentration formaldehyde through recruiting XRCC-1 protein, and may be involved in the regulation of cell apoptosis induced by high-concentration formaldehyde.</p>

Role of poly (ADP-ribose) polymerase 1 in DNA methylation changes induced by hydroquinone in human bronchial epithelial cell / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the DNA methylation changes induced by hydroquinone (HQ) in human bronchial epithelial cells and to explore the role of poly (ADP-ribose) polymerase-l (PARP-l) in this process.</p><p><b>METHODS</b>Human bronchial epithelial 16HBE cells and PARP-l-deficient 16HBE cells (16HBE-shPARP-l cells) were exposed to HQ (10, 20, 40, 60, and 80 µmol/L) for 48h, while control cells were treated with an equal volume of PBS solution. The changes in genomic DNA methylation were investigated by high-performance capillary electrophoresis, and the expression levels of PARP-l and DNA methyltransferase 1 (DNMT1) were measured.</p><p><b>RESULTS</b>The percentages of methylated DNA of overall genome (mCpG%) in 16HBE and 16HBE-shPARP-l cells were 4.89%±0.07% and 9.53%±0.51%, respectively; after treatment with 5-aza-2'-deoxycytidine for 72 h, mCpG% decreased to 3.07±0.12% and 6.34%±0.3%, respectively. The one-way analysis of variance revealed significant differences in mCpG% between the cells exposed to different concentrations of HQ in both 16HBE and 16HBE-shPARP-l groups (F = 61.25, P < 0.01; F = 60.36, P < 0.01). For 16HBE cells treated with HQ (10, 20, 40, 60, and 80 µmol/L), the mRNA expression levels of PARP-1 were 145.0%, 159.0%, 169.0%, 215.0%, and 236.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all); for 16HBE-shPARP-l cells treated with HQ (10, 20, 40, 60, and 80 µmol/L), the mRNA expression levels of PARP-l were 170.0%, 223.0%, 264.0%, 327.0%, and 320.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all). When the dose of HQ reached 20, 40, 60, and 80 µmol/L, the mRNA expression levels of DNMT1 in 16HBE group were 114.0%, 126.0%, 136.0%, and 162.0%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all); when the dose of HQ reached 10, 20, 40, 60, and 80 µmol/L, the mRNA expression levels of DNMT1 in the 16HBE-shPARP-l group were 141.0%, 165.2%, 186.9%, 202.1%, and 217.3%, respectively, compared with those in the control group, with significant differences (P < 0.01 for all).</p><p><b>CONCLUSION</b>HQ can induce hypomethylation in 16HBE cells, and PARP-1 can regulate DNA methylation in 16HBE cells by influencing the expression and activity of DNMT1.</p>

Homoharringtonine combined arsenic trioxide induced apoptosis in human multiple myeloma cell line RPMI 8226: an experimental research / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To clarify the effects and mechanisms of homoharringtonine (HHT) monomer therapy or combination therapy with arsenic trioxide (ATO) on human multiple myeloma (MM) cell line RPMI 8226 in in vitro researches.</p><p><b>METHODS</b>Effects of HHT, ATO, and HHT combined ATO on the growth of MM cell line RPMI 8226 were detected using MTT assay. The morphological changes of cell apoptosis were detected by Hoechst staining. The early apoptosis rate was detected using flow cytometry. Expressions of Caspase-3, Caspase-9, poly-ADP-ribose polymerase (PARP), Bcl-2, Mcl-1, Bcl-xl, and AKT protein were detected by Western blot.</p><p><b>RESULTS</b>HHT and ATO inhibited the proliferation of RPM1 8226 cell line in a time- and dose-dependent manner (P < 0.05). Synergistic effects was shown in the combination group (Cl < 1). HHT and ATO induced the apoptosis of RPMI 8226 in a dose-dependent manner with typical morphological changes of apoptosis and higher early stage apoptosis rate. The enhancement in apoptotic induction was seen when two agents were combined. HHT activated expressions of Caspase-3 and PARP in a dose dependent manner at 24 h. HHT at 40 ng/mL and ATO at 8.5 micromol/L could significantly activate expressions of Caspase-3 and Caspase-9, and down-regulate expressions of anti-apoptotic proteins Bcl-xl and Mcl-1. In addition, the combination therapy of HHT at 40 ng/mL and ATO at 8.5 micromol/L inhibited phosphorylation of AKT in a time-dependent manner.</p><p><b>CONCLUSION</b>HTT, ATO, and combination therapy of HHT and ATO induced the apoptosis of RPMI 8226 cell line possibly through activating Caspase pathways, regulating expressions of Bcl-2 families, and inhibiting phosphorylation of AKT.</p>