Autophagy Mediates Astrogenesis in Adult Hippocampal Neural Stem Cells

Neural stem cells (NSCs) have the ability to self-renew and differentiate into neurons, oligodendrocytes, and astrocytes. Highly dynamic nature of NSC differentiation requires the intimate involvement of catabolic processes such as autophagy. Autophagy is a major intracellular degradation pathway necessary for cellular homeostasis and remodeling. Autophagy is important for mammalian development and its role in neurogenesis has recently drawn much attention. However, little is known about how autophagy is associated with differentiation of NSCs into other neural lineages. Here, we report that autophagy plays a critical role in differentiation of adult rat hippocampal neural stem (HCN) cells into astrocytes. During differentiation, autophagy flux peaked at early time points, and remained high. Pharmacological or genetic suppression of autophagy by stable knockdown of Atg7, LC3 or CRISPR-Cas9-mediated knockout (KO) of p62 impaired astrogenesis, while reintroduction of p62 recovered astrogenesis in p62 KO HCN cells. Taken together, our findings suggest that autophagy plays a key role in astrogenesis in adult NSCs.

miR-205 promotes proliferation and invasion of laryngeal squamous cell carcinoma by suppressing CDK2AP1 expression

BACKGROUND: The aberrant expression of microRNAs (miRNAs) has been found in various types of cancer. miR-205 was reported to be upregulated in laryngeal squamous cell carcinoma (LSCC) tissues, however, the mechanisms by which miR-205 functions as a regulator of LSCC are largely unknown. RESULTS: In this study, Real-time qPCR and Western blot assay showed that expression of miR-205 was upregulated and expression of cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) was downregulated in LSCC tissues. The expression levels of miR-205 were negatively related to those of CDK2AP1 in LSCC tissues and cell lines. Moreover, we found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the CDK2AP1 expression in LSCC cells. 3-(4,5-dimethylthiazal-2-yl)-2,5-diphenyl-tetrazolium bromide assays and transwell invasion assay were performed to test the proliferation and invasion of LSCC cells. Gelatin zymography was used to detect the activity of MMP2 and MMP9. CDK2AP1, c-Myc and CyclinD1 expression in cells was assessed with Western blotting. We found that miR-205 was the upstream regulator of CDK2AP1 and could suppress the expression of CDK2AP1 in LSCC cells. In addition, miR-205 significantly induced cell proliferation and invasion by suppressing CDK2AP1 expression. Consistent with miR-205 inhibitors, overexpressed CDK2AP1 suppressed the activity of MMP2 and MMP9 and c-Myc and CyclinD1 expression in LSCC cells. CONCLUSION: These findings help us to better elucidate the molecular mechanisms of LSCC progression and provide a new theoretical basis to further investigate miR-205 as a potential biomarker and a promising approach for LSCC treatment.

Sinaptogénesis y esquizofrenia: rol de la proteína DISC 1 / Synaptogenesis and Schizophrenia: The role of DISC 1 protein

El presente trabajo aporta información respecto del posible rol en la esquizofrenia del gen DISC 1 y la proteína que este gen codifica. Se realiza un recorrido desde el hallazgo de la translocación cromosómica que llevó a su descubrimiento, hasta la perspectiva actual, que lo conceptualiza como un modulador funcional complejo. La mencionada translocación fue originariamente identificada en una familia escocesa, y se observó que cosegregaba con esquizofrenia y otros trastornos mentales. Actualmente, se considera a DISC 1 como una proteína central dentro de una red de interacciones con otras proteínas - lo que en varios trabajos se denomina interactoma -, tales como NDEL 1, LIS 1 y PDE 4B, entre otras.

This paper provides information regarding the possible role in schizophrenia of the DISC 1 gene and the protein it encodes. It is a tour from the discovery of the chromosomal translocation that led to its discovery, up to the current perspective, which is conceptualized as a complex functional modulator. The above translocation was originally identified in a Scottish family, and it was noted that it cosegregated with schizophrenia and other mental discorders. Currently, DISC 1 is considered as a central protein within its network of protein interactions (named as interactome in several papers), such as NDEL 1, LIS 1 and PDE 4B, among others.

[Dendrosomal curcumin induced apoptosis by suppression of pluripotency genes in 5637 bladder cancer cells]

The anti-cancer properties of curcumin, a poliphenol extract from the rhizome of curry, has been confirmed by many investigators. However, low levels of uptake, tissue distribution and rapid metabolism has limited its application as an anti-cancer drug. This study is aimed at increasing curcumin's water solubility due to a biodegradable, neutral and non-toxic micellar nano-carrier called dendrosome. This study intends to evaluate the role of dendrosomal-curcumin [DNC] in bladder cancer cell growth. We performed the MTT assay, flow cytometry and Annexin V-FLUOS [as an apoptosis detection kit] to evaluate cell death. The genetic mechanism of DNC-induced apoptosis was accomplished by a study of the relative expressions of OCT4A, OCT4B1, SOX-2 and Nanog using real-time PCR. DNC-induced cell death complied with a time and dose-dependent paradigm in the 5637 cell line. Cell cycle analysis revealed that the number of cells increased in pre-G1 and gradually decreased in G1 and S phases. This showed the inhibitory property of dendrosomal-curcumin on DNA synthesis. Data from real-time PCR determined that expressions of OCT4A, OCT4B1, SOX-2 and Nanog could be related to 5637 cancer cell growth. Dendrosomal-curcumin significantly suppressed mRNA expression of the above mentioned genes [p<0.01]. The data showed that DNC induced apoptosis by suppression of pluripotency genes in 5637 bladder cancer cells, which confirmed the useful characteristic of nano-drug in bladder cancer therapy.

Suppression of EphB4 improves the inhibitory effect of mTOR shRNA on the biological behaviors of ovarian cancer cells by down-regulating Akt phosphorylation / 华中科技大学学报（医学）（英德文版）

The aim of the present study was to examine the effects of suppression of EphB4 and/or mTOR on the biological behaviors of ovarian cancer cells, and the potential regulatory pathways. Antisense EphB4 vectors and shRNA vectors targeting mammalian target of rapamycin (mTOR) were constructed and transfected into A2780 and SKOV3 cells (two ovarian cancer cell lines). The effects of the antisense EphB4 vectors and the shRNA vectors on the proliferation, apoptosis and invasion of ovarian cancer cells were measured, and the expression of EphB4, mTOR and Akt detected. The results showed that transfection with mTOR shRNA could inhibit growth, induce apoptosis, and reduce invasive ability of ovarian cancer cells, which was accompanied by downregulation of EphB4, mTOR and Akt. The inhibitory effects on cell growth caused by mTOR shRNA alone were weaker than those by antisense pEGFP-C1-EphB4. In the antisense pEGFP-C1-EphB4-transfected cells, it was found that EphB4 knockdown could decrease the mTOR expression and slightly reduce the Akt phosphorylation. Significant suppressive effects on cell growth were observed in cells co-transfected with antisense pEGFP-C1-EphB4 and mTOR shRNA. In co-transfection group, the expression levels of EphB4, mTOR and Akt were distinctly lower than those in other groups. It was concluded that suppression of EphB4 may inhibit the growth of ovarian cancer cells by downregulation of the PI3K/Akt/mTOR pathway, and reverse Akt phosphorylation induced by mTOR shRNA. Inhibition of EphB4 and mTOR combined may cooperatively suppress the biological behaviors of ovarian cancer cells.

Characterization of cry2-type genes of Bacillus thuringiensis strains from soil-isolated of Sichuan basin, China

Sichuan basin, situated in the west of China, is the fourth biggest basin in China. In order to describe a systematic study of the cry2-type genes resources from Bacillus thuringiensis strains of Sichuan basin, a total of 791 Bacillus thuringiensis strains have been screened from 2650 soil samples in different ecological regions. The method of PCR-restriction fragment length polymorphism (PCR-RFLP) was used to identify the type of cry2 genes. The results showed that 322 Bacillus thuringiensis strains harbored cry2-type genes and four different RFLP patterns were found. The combination of cry2Aa/cry2Ab genes was the most frequent (90.4 percent), followed by cry2Aa (6.8 percent) and cry2Ab alone (2.5 percent), and only one novel type of cry2 gene was cloned from one isolate (JF19-2). The full-length of this novel gene was obtained by the method of thermal asymmetric interlaced PCR (Tail-PCR), which was designated as cry2Ag1 (GenBank No. ACH91610) by the Bt Pesticide Crystal Protein Nomenclature Committee. In addition, the result of scanning electron microscopic (SEM) observation showed that these strains had erose, spherical, bipyramidal, and square crystal. And the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) demonstrated that these strains harbored about one to three major proteins. These strains exhibited a wide range of insecticidal spectrum toxic to Aedes aegypti (Diptera) and Pieris rapae Linnaeus, 1758 (Lepidoptera). Particularly, JF19-2 contained cry2Ag gene had the highest insecticidal activity. All these researches mentioned above revealed the diversity and particularity of cry2-type gene resources from Bacillus thuringiensis strains in Sichuan basin.

Cytological characterization of an Aspergillus nidulans mutant from a strain with chromosomic duplication

A development mutant, named V103, was obtained spontaneously from the A strain of A. nidulans. The A strain contains a duplicated segment of chromosome I that has undergone translocation to chromosome II (I ¨ II). It is mitotically unstable and generates phenotypically deteriorated types, some with enhanced stability. The deteriorated variants of A. nidulans show abnormal development, exhibiting slower colony growth, variations in colony pigmentation and changes in conidiophore structure. The alterations observed in the conidiophore include fewer metulae and phialides, further elongation and ramification of these structures, delayed nuclear migration and the presence of secondary conidiophores.

Identification of genes associated with Egyptian cotton fiber development using combination of SSH, microarrays and real time RT-PCR

One of the major limitations in the application of genetic engineering or conventional breeding methods in improving cotton fiber is the paucity of information about fiber related genes. Availability of Gossypium barbedense Giza 88 extra-long staple cotton fiber traits provides a unique opportunity to study fiber-associated genes because of its high-quality fiber compared to Giza 90 long staple fiber. To understand the molecular basis of cotton fiber development, we used the combination of suppression subtractive hybridization [SSH], microarrays and real-time reverse transcription-polymerase chain reaction [RT-PCR] technologies to identify the potential genes related to cotton fiber development. Utilizing mRNAs from 15 days post anthesis [dpa] fibers, we constructed a SSH cDNA library from Giza 88 extra long staple fiber as the tester and Giza 90 long staple fiber as the driver. The SSH cDNA library was then screened using microarrays. Microarrays analysis showed that 20 genes were differentially expressed in Giza 88 15-dpa fiber compared to Giza 90 as confirmed by real time RT-PCR. These genes include two beta-tubulins, an actin, a putative kinesin light chain, a cellulose synthase, glycosyl hydrolase family protein, pyruvate decarboxylase, glycoside hydrolase family, GDP-mannose pyrophosphorylase, dynaminlike protein, annexin and a number of genes involved in signal transduction, and protein, nucleic acid metabolism and lipid metabolisms

Presença da mutação Arg337His do supressor tumoral P53 e mapa de deleção do cromossomo 17 em crianças e adultos com tumores adrenocorticais / Presence of the mutation Arg337His of the tumor suppressor P53 and deletion mapping of chromosome 17 in children and adults with adrenocorticol tumors

A mutação germinativa, Arg337His, do gene supressor tumoral p53 foi pesquisada em 71 pacientes brasileiros portadores de tumores adrenocorticais isolados. Análise de segregação evidenciou um mesmo haplótipo, associado à mutação Arg337His, configurando efeito fundador para esta mutação. Mapa de deleção para o cromossomo 17 demonstrou uma elevada freqüência 17/29 (59por cento), de perda completa deste cromossomo tanto em tumores benignos quanto malignos mostrando que não há correlação entre perda do cromossomo 17 e agressividade tumoral nestes pacientes. Instabilidade cromossômica envolvendo os cromossomos 2, 9 e 11 foi verificada nos pacientes que perderam o cromossomo 17. Perda de 3 ou mais cromossomos pode contribuir para o diagnóstico de malignidade nos tumores adrenocorticais / The Arg337His mutation of the P53 tumor suppressor was investigated in 71 Brazilian patients with isolated adrenocortical tumors. Segregation analysis evidenced the same haplotype, associated with Arg337His mutation, indicating a founder effect. Deletion mapping for chromosome 17 demonstrated a high frequency 17/29 (59 per cent) of chromosomal loss in both, benign and malignant tumors, without correlation between loss of chromosome 17 and tumor behavior. Chromosomal instability, involving chromosomes 2, 9 and 11 was verified in patients that had loss of chromosome 17. The concomitant loss involving of 3 or more chromosomes can contribute for diagnosis of malignancy in adrenocortical tumors...

Inactivation of the p15 gene in children with acute lymphoblastic leukemia

CONTEXT: Tumor suppressor genes act on the control of cell cycle progression. In pediatric neoplasias, some of these genes may be considered to be markers for diagnosis or relapse, thus probably representing prognostic indicators. OBJECTIVE: To study the inactivation of the p15 gene in children with acute lymphoblastic leukemia. TYPE OF STUDY: Retrospective study. SETTING: Laboratory of Molecular Biology, Department of Pediatrics, Faculdade de Medicina de Ribeiräo Preto, Universidade de Säo Paulo. PARTICIPANTS: Eighty-three children and adolescents with acute lymphoblastic leukemia were studied, with the examination of 83 bone marrow samples obtained at diagnosis, four obtained also during relapse, and two cerebrospinal fluid samples obtained from two cases of isolated relapse in the central nervous system. MAIN MEASUREMENTS: Homologous deletion of the p15 gene by multiplex polymerase chain reaction, and screening for point mutations by polymerase chain reaction/single-strand conformational polymorphism. RESULTS: Deletion of exon 2 of the p15 gene was observed in 15 children, including one case in which deletion was only verified during isolated central nervous system relapse. No case of exon 1 deletion, or that was suggestive of point mutations, was observed and no association between p15 gene inactivation and classic risk factors was established. CONCLUSION: According to the literature, inactivation of the p15 gene by deletion of exon 2 in acute lymphoblastic leukemia found in the population studied would be considered to be a molecular marker for diagnosis or relapse. However, no correlation between p15 gene deletion and clinical prognostic indicators was observed

Mutación puntual del gen supresor de tumores TP53 en lesiones preneoplásicas y neoplásicas del estómago / Mutations of TP53 suppressor gene in pre-neoplastic and neoplastic lesions of the stomach: cross-sectional study in a high risk region

Background: In the current model for the development of gastric cancer, regions of multifocal atrophic gastritis give rise to intestinal metaplasia, dysplasia and finally, adenocarcinoma. Aim: To study the frequency and characteristics of TP53 gene mutations in preneoplastic and neoplastic lesions of the stomach. Material and methods: DNA sequencing of the TP53 gene was performed in 46 patients with gastric carcinoma. Normal mucosa, intestinal metaplasia and invasive adenocarcinoma tissues were obtained by scraping 6-Ám histological sections from formalin-fixed and paraffin-embedded tissue. Results: DNA sequencing of exons 5-9 of the TP53 gene demonstrated a mutation in 31 percent of patients. These findings were seen both in tumoral tissue (13 cases) and in intestinal metaplasia (2 cases). Most mutations were found in exons 5 and 8, and the majority of them were transitions (10 out of 19 mutations). Discussion: Patients with gastric cancer showed a frequency of TP53 mutations similar to that previously communicated in populations with low gastric cancer risk. Moreover, there was a predominance of transitions, genetic alterations that are identified with carcinogenesis associated with N-nitrosamine compounds. Finally, mutations of TP53 gene were detected in areas of intestinal metaplasia

Mutaçäo do gene p53 induzindo predisposiçäo genética ao câncer: relato de um caso da síndrome de Li-Fraumeni / P53 gene mutation inducing hereditary cancer predisposition: case report of Li-Fraumeni syndrome

A síndrome de Li-Fraumeni é uma síndrome de predisposiçäo familiar ao câncer, caracterizada pela presença de múltiplos tumores, tais como sarcomas, carcinomas de mama, tumores cerebrais e leucemia. O caso relatado é de uma paciente feminina de 37 anos, que apresenta uma significativa história familiar de câncer, bem como história pessoal de seis diferentes tumores primários (um de cólon, um nevus displásico, um de ovário e três de mama). O sequenciamento do gene supressor de tumor p53 em seus linfócitos presentes no sangue periférico revelou uma mutaçäo do aminoácido triptofano (TGG) para um códon de parada prematuro (TAG), no nucleotídeo 437 do códon 146 do éxon 5 deste gene. As implicaçöes clínicas, preventivas e éticas deste caso säo também abordadas.

Patología molecular del cáncer pulmonar y sus lesiones precursoras: parte I, patología molecular del cáncer pulmonar / Molecular pathology of lung cancer and its precursor lesions: part I molecular pathology of lung cancer

En las últimas décadas se ha producido un gran avance en el conocimiento de las alteraciones moleculares que participan en la patogenia del cáncer pulmonar. Se ha determinado que esta neoplasia es el producto de un gran número de alteraciones genéticas (estimulando entre 10 y 20) que afectarían a oncogenes recesivos y a genes supresores de tumores. Además, se han establecido patrones de alteraciones genéticas en los diferentes tipos clínico-patológicos de cáncer pulmonar. Este conocimiento se ha aplicado al estudio de las alteraciones genéticas que participan en la progresión de las lesiones precursoras de esta neoplasia y al de sarrollo de métodos de detección precoz y control de pacientes con lesiones precursoras de cáncer pulmonar

Tema de revisión Los genes supresores de tumores y el cáncer / Tumor suppressor genes and cancer

En el siguiente trabajo de revisión, se exponen los aspectos más relevantes acerca de los genes supresores y el papel que éstos juegan en la aparición y desarrollo del cáncer. Para abordar esta novedosa temática, se mencionan los diferentes tipos de genes supresores de tumores así como la asociación de los mismos con las diferentes enfermedades malignas. Se hizo énfasis en el modo de acción de algunos de ellos, por considerar que son de gran importancia dentro de la célula, en el control de los procesos de proliferación y diferenciación. Seguidamente se describen de forma breve algunas de las principales herramientas con que se cuenta para la determinación de las diferentes alteraciones en estos genes supresores. Finalmente se aborda la importancia del conocimiento de los mismos en el diseño de nuevas terapias que actúen de forma específica y dejen atrás los efectos indeseables de las terapias convencionales

Hiperplasia adrenal congénita e hipertensión arterial / Congenital adrenal hyperplasia and arterial hypertension

El fenotipo asociado a Hiperplasia Adrenal Congénita (HAC) fue descripto por primera vez en 1865 pero la naturaleza de este desorden permaneció obscura hasta mediados del siglo XX. Se denomina HAC a un conjunto de enfermedades hereditarias que producen un trastorno en la esteroideogénesis suprarrenal. Dado que dicho trastorno afecta siempre la síntesis de cortisol condiciona una hipersecreción de adrenocorticotrofina (ACTH), que implicará, una hipertrofia de la glándula suprarrenal dando origen al nombre de ésta patología. Actualmente, mediante técnicas de biología molecular se pueden identificar mutaciones específicas que afectan a los genes de las proteínas involucradas en la biosíntesis de cortisol; estas permiten su diagnóstico precoz y la aplicación de un tratamiento adecuado. El déficit de 11Bhidroxilasa (11BOH) es la segunda causa más frecuente de HAC, apróximadamente 2/3 de los pacientes con este desorden tienen hipertensión arterial, por otra parte, en el déficit de 17 alfahidroxilasa (17OH), encontramos mujeres hipogonádicas y varones con genitales ambiguos e hipertensión arterial.

Mutación del gen p53 en el cáncer de la vesícula biliar / P53 gene mutation in gallbladder cancer

Background: Gallbladder cancer frequency and mortality renders it one of the most important neoplastic diseases in Chile. P53 tumor suppressor gene has been studied in most types of cancer, but there is scarce information about it in gallbladder cancer. Aim: To study the frequency of P53 gene mutation in gallbladder cancer in the ninth region of Chile. Material and methods: In 25 pathological samples of gallbladder cancer, the direct amplification and sequencing of p53 gene exons 5,6,7,8-8 was possible. Results: Seventeen punctual mutations were observed in 13 cases (52 percent). There were 10 transitions, 5 transversions, one insertion (codon 194) and one deletion (codon 186). Eight cases had mutations in exon 5, six had mutations in exon 6, two had mutations in exon 7 and one had mutations in exons 8-9. In 14 of 25 cases, gene p53 protein was positive. When immunohistochemical expression of gene p53 protein was positive in more than 20 percent of cells, there was a high correlation between genetic alterations and immunohistochemical expression of the protein, with a specificity, sensitivity, positive and negative predictive values over 80 percent. Conclusions: P53 gene mutation is observed in a high proportion of gallbladder cancers at it can be accurately detected with conventional immunohistochemical techniques. The importance of this gene in the genesis of this carcinoma should be determined studying preneoplastic lesions and early carcinomas

Síndrome mielodisplásico: evaluación de la proteína p53 como factor pronóstico / Myelodysplastic syndrome: evaluation of p53 prognostic factor

Los síndromes mielodisplásicos representan un estado preleucémico en el cual existe una falla de los progenitores hematopoyéticos para diferenciarse normalmente. Se ha observado que estos cuadros clínicos obedecen a un desorden clonal y que el incremento de células blásticas en la médula ósea se correlaciona con un pobre pronóstico. Si bien no se conocen completamente los mecanismos moleculares que subyacen a esta progresión, se han detectado diversas anomalías cromosómicas y mutaciones genéticas. La proteína p53 es el producto de un gen supresor de tumor relacionado con los mecanismos de control de la división celular y en el desarrollo de neoplasias. Para determinar si p53 tiene participación en el proceso mielodisplásico, evaluamos en este estudio las alteraciones de la proteína p53 y de su gen, empleando inmunohistoquímica y polimorfismo conformacional de cadena simple (SSCP) en un grupo de 21 pacientes con mielodisplasia, relacionando los hallazgos con la transformación leucémica, en un seguimiento a 5 años. Se encontraron alteraciones de la proteína en 4/21 casos (19 por ciento) y mutaciones del gen que la codifica también en 4/21 pacientes (19 por ciento). Seis pacientes (sobre 17 evaluables) desarrollaron leucemia aguda. El 50 por ciento de ellos presentó alteraciones de la proteína p53...