RNA-sequencing Profiles of Cell Cycle–Related Genes Upregulated during the G2-Phase in Giardia lamblia

To identify the component(s) involved in cell cycle control in the protozoan Giardia lamblia, cells arrested at the G1/S- or G2-phase by treatment with nocodazole and aphidicolin were prepared from the synchronized cell cultures. RNA-sequencing analysis of the 2 stages of Giardia cell cycle identified several cell cycle genes that were up-regulated at the G2-phase. Transcriptome analysis of cells in 2 distinct cell cycle stages of G. lamblia confirmed previously reported components of cell cycle (PcnA, cyclin B, and CDK) and identified additional cell cycle components (NEKs, Mad2, spindle pole protein, and CDC14A). This result indicates that the cell cycle machinery operates in this protozoan, one of the earliest diverging eukaryotic lineages.

The effects of nonyl phenoxypolyethoxyl ethanol on cell damage pathway gene expression in SK-NSH cells

BACKGROUND/AIMS: Most pesticide formulations contain both chief and additive ingredients. But, the additives may not have been tested as thoroughly as the chief ingredients. The surfactant, nonyl phenoxypolyethoxylethanol (NP40), is an additive frequently present in pesticide formulations. We investigated the effects of NP40 and other constituents of a validamycin pesticide formulation on cell viability and on the expression of genes involved in cell damage pathways. METHODS: The effects of validamycin pesticide ingredients on cell viability and of NP40 on the mRNA expression of 80 genes involved in nine key cellular pathways were examined in the human neuroblastoma SK-N-SH cell line. RESULTS: The chemicals present in the validamycin pesticide formulation were cytotoxic to SK-N-SH cells and NP40 showed the greatest cytotoxicity. A range of gene expression changes were identified, with both up- and down-regulation of genes within the same pathway. However, all genes tested in the necrosis signaling pathway were down-regulated and all genes tested in the cell cycle checkpoint/arrest pathway were up-regulated. The median fold-change in gene expression was significantly higher in the cell cycle checkpoint/arrest pathway than in the hypoxia pathway category (p = 0.0064). The 70 kDa heat shock protein 4 gene, within the heat shock protein/unfolded protein response category, showed the highest individual increase in expression (26.1-fold). CONCLUSIONS: NP40 appeared to be particularly harmful, inducing gene expression changes that indicated genotoxicity, activation of the cell death (necrosis signaling) pathway, and induction of the 70 kDa heat shock protein 4 gene.

Sheep gastrointestinal helminthiasis in the Sertão region of Paraíba State, Northeastern Brazil: prevalence and risk factors / Helmintoses gastrintestinais de ovinos no Sertão do Estado da Paraíba, Nordeste do Brasil: prevalência e fatores de riscos

In this study, we aimed to establish the prevalence and risk factors relating to gastrointestinal helminthiasis, and to characterize the sanitary management practiced among sheep herds in the Sertão region of the state of Paraíba, northeastern Brazil, based on factors that condition the ways of controlling these parasites in these herds. The research was carried out between April and July 2012. We visited 54 farms, where fecal and blood samples were individually collected from 465 animals. On each farm, a questionnaire was applied to gather information on variables relating to potential risk factors. The prevalence of sheep gastrointestinal helminthiasis in the region was 75.9%. At least one animal tested positive for this helminthiasis on 53 (98.1%) of the 54 farms evaluated. The eggs per gram of feces (EPG) analysis showed the following infection burdens: 51.8% with mild infection, 27.1% moderate infection, 9.9% heavy infection and 11.2% fatal infection. Among the sheep farms visited, anthelmintics were used on 81.5% (p <0.05). The most relevant risk factor in this study was the farm area, because it defines the area available for grazing animals. Properties with many animals and little pasture area, which are the most abundant type in the Sertão region of Paraíba, tend to have high prevalence of gastrointestinal helminthiasis, because the animals are more prone to reinfection. The Sertão region of Paraíba presents high prevalence of gastrointestinal helminthiasis among sheep, and the farm area is the most relevant risk factor for the development of these parasites.

Objetivou-se determinar a prevalência e os fatores de risco para as helmintoses gastrintestinais, caracterizando o manejo sanitário sob fatores condicionantes das formas de controle dessas parasitoses em rebanhos de ovinos da região do Sertão da Paraíba. A pesquisa foi desenvolvida no período de abril a julho de 2012. Foram visitadas propriedades, utilizando-se 465 animais, sendo coletadas individualmente amostras de fezes e sangue durante as visitas. Em cada propriedade, foi aplicado questionário para a coleta de informações acerca de variáveis que atuariam como possíveis fatores de risco. Observou-se que a prevalência das helmintoses gastrintestinais de ovinos na região do Sertão da Paraíba foi de 75,9%. Pelo menos um animal foi positivo para essas helmintoses, em 53 (98,1%) das 54 propriedades avaliadas. A análise de OPG (Ovos Por Gramas de Fezes) demonstrou que 51,8% dos animais apresentaram infecção leve, 27,1% infecção moderada, 9,9% infecção pesada e 11,2% infecção fatal. A utilização de anti-helmínticos ocorreu em 81,5% das propriedades (p <0,05). O fator de risco mais relevante neste estudo foi a área da propriedade, porque delimita a área de pastejo do animal. Propriedades com muitos animais e pouca área de pastejo, que são as mais abundantes no Sertão da Paraíba, tendem a apresentar alta prevalência de helmintoses gastrintestinais, pois os animais estão mais propensos à reinfecção. A região do Sertão da Paraíba apresenta uma elevada prevalência de helmintoses gastrintestinais em ovinos, e a área das propriedades é o fator de risco mais relevante para o desenvolvimento dessas parasitoses.

Experimental study of inhibition of tumor cell proliferation by a novel gene SPATA12 / 中南大学学报(医学版)

OBJECTIVE@#To explore the inhibitory role of spermatogenesis-associated gene 12 (SPATA12) on tumor cell proliferation and its possible mechanism.@*METHODS@#The expression pattern of SPATA12 in testicular tumors was investigated by in situ hybridization analysis using tissue microarrays. The effects of SPATA12 on tumor cell proliferation and colony formation was detected by 3-(4.5-dimethylthiazol-2- yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and colonyforming assays, respectively. The changes of expression level of cell cycle genes in tumor cells were detected by reverse transcription polymerase chain reaction(RTPCR).@*RESULTS@#In situ hybridization analysis showed that the SPATA12 was highly expressed in normal adult testis, but lacking in testicular tumors such as seminoma. MTT assay and colony-forming assay indicated that the exogenous expression of SPATA12 could suppress both tumor cell proliferation and colony formation. RT-PCR showed that the expression of cyclin A1 gene was markedly suppressed and the level of cyclin D1 was somewhat reduced following SPATA12 transfection. However, no obvious changes were observed in mRNA expression of cyclin B1 or cyclin E1 after SPATA12 transfection.@*CONCLUSION@#SPATA12 could be an inhibitor during the development of tumor via regulation of cell cycle genes.

Preferential Cytotoxic Effect of Genistein on G361 Melanoma Cells Via Inhibition of the Expression of Focal Adhesion Kinase

Resistance to the induction of apoptosis is a possible mechanism by which tumor cells can survive anti-neoplastic treatments. Melanoma is notoriously resistant to anti-neoplastic therapy. Previous studies have demonstrated focal adhesion kinase (FAK) overexpression in melanoma cell lines. Given its probable role in mediating resistance to apoptosis, many researchers have sought to determine whether the downregulation of FAK in melanoma cells would confer a greater sensitivity to anti-neoplastic agents. Genistein is a known inhibitor of protein-tyrosine kinase (PTK), which may attenuate the growth of cancer cells by inhibiting the PTK-mediated signaling pathway. This present study was undertaken to investigate the effect of genistein on the expression of FAK and cell cycle related proteins in the G361 melanoma cell line. Genistein was found to have a preferential cytotoxic effect on G361 melanoma cells over HaCaT normal keratinocytes. Genistein decreased the expression of 125 kDa phosphotyrosine kinase and the FAK protein in particular. Genistein treatment did not affect the expression of p53 in G361 cells in which p21 is upregulated. The expression of cyclin B and cdc2 was downregulated by genistein treatment. Taken together, our data indicate that genistein induces the decreased proliferation of G361 melanoma cells via the inhibition of FAK expression and regulation of cell cycle genes. This suggests that the use of genistein may be a viable approach to future melanoma treatments.

DNA repair and synthetic lethality / 国际口腔科学杂志·英文版

Tumors often have DNA repair defects, suggesting additional inhibition of other DNA repair pathways in tumors may lead to synthetic lethality. Accumulating data demonstrate that DNA repair-defective tumors, in particular homologous recombination (HR), are highly sensitive to DNA-damaging agents. Thus, HR-defective tumors exhibit potential vulnerability to the synthetic lethality approach, which may lead to new therapeutic strategies. It is well known that poly (adenosine diphosphate (ADP)-ribose) polymerase (PARP) inhibitors show the synthetically lethal effect in tumors defective in BRCA1 or BRCA2 genes encoded proteins that are required for efficient HR. In this review, we summarize the strategies of targeting DNA repair pathways and other DNA metabolic functions to cause synthetic lethality in HR-defective tumor cells.

The role of BRCA1 in DNA damage response

BRCA1 is a well-established tumor suppressor gene, which is frequently mutated in familial breast and ovarian cancers. The gene product of BRCA1 functions in a number of cellular pathways that maintain genomic stability, including DNA damage-induced cell cycle checkpoint activation, DNA damage repair, protein ubiquitination, chromatin remodeling, as well as transcriptional regulation and apoptosis. In this review, we discuss recent advances regarding our understanding of the role of BRCA1 in tumor suppression and DNA damage response, including DNA damage-induced cell cycle checkpoint activation and DNA damage repair.

A comparison between genetic portraits of normal osteoblasts and osteosarcoma cell lines.

BACKGROUND: Osteosarcoma (OS) is the most frequent malignant bone tumor occurring in young patients in the first two decades of life. Metastases are the cause of 90% of cancer deaths for patients with OS. OS of the jaw is rare and aggressive malignancy constitutes approximately 5-13% of all cases of skeletal OS. Chemotherapy plus surgery are the first choice for treatment. AIMS: Because OS cell lines (OCLs) should share a common pathway with primary OS and new drugs are screened in in vitro systems, new insight about the genetic profiling of OCLs is of paramount importance to a better understanding of the molecular mechanism of this rare tumor and detecting a potential target for specific therapy. MATERIALS AND METHODS: The SAOS2 and TE85 cell lines were analysed using DNA microarrays containing 19,000 genes. Several genes in which expression was significantly differentially expressed in OCLs vs. normal osteoblast (NO) were detected. RESULTS: The differentially expressed genes cover a broad range of functional activities: (a) cell cycle regulation, (b) cell differentiation, (c) apoptosis, and (d) immunity. CONCLUSION: The reported data can be relevant to a better understanding of the biology of OS and as a model for comparing the effect of drugs used in OS treatment.

Investigation on the molecular mechanisms of anti-hepatocarcinoma herbs of traditional Chinese medicine by cell cycle microarray / 中国中药杂志

<p><b>OBJECTIVE</b>To design DNA microarray and investigate the molecular anti-tumor mechanism of herbs of traditional Chinese medicine.</p><p><b>METHOD</b>cDNA microarrays consisting of 56 probes representing 24 human cell cycle genes were constructed, Four anti-hepatocarcinoma herbs including Radix Linderae, Hebra Artemisiae Annuae, Radix Amebiae, Radix Astragli, were chosen. Effects of herbs on SMMC-7721 cell cycle were observed by flow cytometry assay. Effects of herbs on cell cycle gene expression in SMMC-7721 cells were analyzed by comparing hybridization of Dig-Labeled cDNAs from herb-treated cells and cDNAs from untreated cells.</p><p><b>RESULT</b>Expressions of cell cycle geneswere changed in different degrees after herbs treated. Some genes were down-regulated and some genes were up-regulated. The changes in gene expression agreed with the results of flow cytometry assay.</p><p><b>CONCLUSION</b>The results suggest that these herbs may have effects on cell cycle and DNA damage checkpoint genes which may be the mechanism of the herbs, and DNA microarray can be used to investigate the biological function of extracts of traditional Chinese medicine.</p>

p53-independent checkpoint controls in a plant cell model

Allium cepa L. meristems were used as a plant model to study the p53-independent control of S and G2 phases by checkpoint pathways, in eukaryotic cells. Checkpoint blocks were induced at early and mid S by hydroxyurea. After their spontaneous override, cells became accumulated in G2-prophase, giving rise later on to a delayed mitotic wave. Cell growth was maintained during the checkpoint blocks, as the delayed mitoses were larger in size than the control ones. Under continuous hydroxyurea treatment, the delayed mitotic was formed by two subpopulations: normal mitoses corresponding to cells having properly recovered from the checkpoint block, and abnormal ones resulting from checkpoint adaptation. These latter cells displayed broken chromatids as they had unduly overriden the G2 checkpoint block, without completing DNA repair. The frequency of the checkpoint-adapted mitoses increased with the hydroxyurea concentration from 0.25 to 1.0 mM. However, from 1 mM hydroxyurea upwards, some of the cells lost their competence for checkpoint adaptation. Therefore, the dose of a genotoxic agent that still allows G2 checkpoint adaptation should always be applied in order to get rid of uncontrolled proliferating cells. This is specially suitable for cells lacking a functional p53 protein.

Effects of Postaglandin E1 on the Oxidative Stress Injury Index and the Expression of PCNA in Vein Grafts of Rabbit Carotid Arteries

BACKGROUND: This study investigated the protective mechanism of Prostagladin E1 (PGE1) against intimal hyperplasia after vein interposition grafts in rabbits. It has been demonstrated that active oxygen species contribute to vascular smooth muscle cell growth via early cell cycle gene activation. We attempted to study whether PGE1 had an effect on the inhibition of the oxidative stress injury index (8-OHdG, MDA). METHODS: Forty-eight jugular vein grafts were inserted into the carotid arteries of male hyperlipidemic New Zealand white rabbits, which were divided into 2 groups (saline group and PGE1 group). Saline and Prostaglandin E1 (0.1 microgram/kg/min) were administered as a continuous infusion for 2 hours every day from just before graft interposition to harvest. The vein grafts were harvested at 6 hour, 1 day, 1 week, and 2 week after grafting and rapidly stored in liquid nitrogen ( 70oC). 8-OHdG was measured by using high performance liquid chromatography coupled with electrochemical detection (HPLC-EC), and malondialdehyde (MDA) was measured by using thiobarbituric acid (TBA) assay. PC 10 index and intimal thickness of the grafts were measured with a computer digitalized image analyzer. RESULTS: There was no difference in 8-OHdG levels between the saline and the PGE1 groups. PGE1 had more inhibitory effect on the MDA level as an oxidative stress injury index, but its action was restricted to 1 day. A morphometric analysis and an immunohistochemical study showed that the PGE1 group had more suppressive effects both in intimal thickeness and proliferating cell nuclear antigen (PCNA) expression than the saline group (p<0.05). CONCLUSION: These results suggest that PGE1 is effective in preventing intimal hyperplasia after vein interposition grafts in rabbits and may play a role in inhibiting oxidative stress injury.

Expressão dos genes CDC25A e p27 em linfomas não-Hodgkin de células B / CDC25A abd o27 gene expression in b-cell non-Hodgkin's lymphomas

A progressão da divisão celular é regulada pela interação de ciclinas, quinases ciclino-dependentes (CDKS) e inibidores de CDKS (CDKIs).A fosfatase CDC25A pertence a um grupo de fosfatases de dupla especificidade que ativam as CDKs por meio da remoção de fosfatos inibitórios presentes nos resíduos de treonina e tirosina das posições 14 e 15, respectivamente. Diferentemente das fosfatases CDC25B e CDC25C, a CDC25A é predominantemente expressa na fase Gl, e sofre fosforilação durante a transição Gl/S do cicio celular, resultando em aumento de sua atividade enzimática. A fosforilação da enzima CDC25A ocorre na sua extremidade regulatória N-terminai, a qual contém alta densidade de motivos de Ser/ThrPro. Esta fosforiiação é dependente de complexos ciclina E-CDK2, gerando um mecanismo de auto-amplificação essencial para que a célula entre na fase S. A cooperação entre o gene CDC25A e versões mutantes de H-ras ou deleção de Rb foi vista na transformação de fibrobiastos de ratos, e o gene CDC25A é um alvo transcricional relevante do proto-oncogene c-myc, exercendo um importante papel tanto como mediador de proliferação celular bem como de apoptose induzida por c-myc. O gene p27 é um inibidor de CDK e um potencial gene supressor de tumor implicado em bloqueio na fase Gl mediado por TGF-0 e contato celular. A proteína p27 inibe fortemente os complexos ciclina-CDKs, e sua perda de função tem sido implicada na oncogênese. Objetivando investigar a importância dos genes CDC25A e p27 no desenvolvimento e progressão de doenças linfoproliferativas, no presente estudo 93 casos de linfoma não-Hodgkin de células B (LNH-B) foram estudados através de técnica de hibddizacao in situ com sondas de RNA marcadas com digoxigenina em tecido fixado em formalina, a fim de se avaliar a expressão de RNA mensageiro do gene CDC25A. A expressão da proteína p27 também foi avaliada nos mesmos casos através de técnica de imuno-histoquímica. Os pacientes com LNH-B foram divididos em dois grandes grupos: o primeiro constituído por 42 linfomas de baixo grau de malignidade (30 linfomas de pequenas células, 9 linfomas foliculares de pequenas células clivadas, e 3 linfomas foliculares mistos); e o outro grupo constituído por 51 linfomas de grau intermediário e de alto grau de malignidade (3 linfomas foliculares de grandes células, 4 linfomas difusos de pequenas células crivadas, 2 linfomas difusos mistos, 31 linfomas difusos de grandes célula...(truncado..)

Introducción a la genética médica / Introduccion to the medical genetics

La genética médica, se la puede considerar ya como una rama de la genética humana. Los avances científicos que a nivel cromosómico se han desarrollado, en base al estudio de los principios genéticos y cromosómicos, determinan que muchos de los fundamentos médicos de las enfermedades, no se limitan a los trastornos cromosónicos o genéticos, sino que abarcan los aspectos de la hetereogenidad génetica de las emfermedades. Establece los conceptos genéticos indispensables en el proceso de formación de los profesionales de la salud, en particular de los médicos