Résumé
Aberrant regulation of miRNA genes contributes to pathogenesis of a wide range of human diseases, including cancer. The TAR DNA binding protein 43 (TDP-43), a RNA/DNA binding protein associated with neurodegeneration, is involved in miRNA biogenesis. Here, we systematically examined miRNAs regulated by TDP-43 using RNA-Seq coupled with an siRNA-mediated knockdown approach. TDP-43 knockdown affected the expression of a number of miRNAs. In addition, TDP-43 down-regulation led to alterations in the patterns of different isoforms of miRNAs (isomiRs) and miRNA arm selection, suggesting a previously unknown role of TDP-43 in miRNA processing. A number of TDP-43 associated miRNAs, and their candidate target genes, are associated with human cancers. Our data reveal highly complex roles of TDP-43 in regulating different miRNAs and their target genes. Our results suggest that TDP-43 may promote migration of lung cancer cells by regulating miR-423-3p. In contrast, TDP-43 increases miR-500a-3p expression and binds to the mature miR-500a-3p sequence. Reduced expression of miR-500a-3p is associated with poor survival of lung cancer patients, suggesting that TDP-43 may have a suppressive role in cancer by regulating miR-500a-3p. Cancer-associated genes LIF and PAPPA are possible targets of miR-500a-3p. Our work suggests that TDP-43-regulated miRNAs may play multifaceted roles in the pathogenesis of cancer.
Sujets)
Animaux , Humains , Souris , Cellules cultivées , Protéines de liaison à l'ADN , Métabolisme , Test de retard de migration électrophorétique , Immunoprécipitation , microARN , Génétique , Métabolisme , Tumeurs , Génétique , MétabolismeRésumé
Ubiquitin specific protease 33 (USP33) is a multifunctional protein regulating diverse cellular processes. The expression and role of USP33 in lung cancer remain unexplored. In this study, we show that USP33 is down-regulated in multiple cohorts of lung cancer patients and that low expression of USP33 is associated with poor prognosis. USP33 mediates Slit-Robo signaling in lung cancer cell migration. Downregulation of USP33 reduces the protein stability of Robo1 in lung cancer cells, providing a previously unknown mechanism for USP33 function in mediating Slit activity in lung cancer cells. Taken together, USP33 is a new player in lung cancer that regulates Slit-Robo signaling. Our data suggest that USP33 may be a candidate tumor suppressor for lung cancer with potential as a prognostic marker.
Sujets)
Femelle , Humains , Mâle , Adulte d'âge moyen , Technique de Western , Lignée cellulaire tumorale , Mouvement cellulaire , Génétique , Physiologie , Études de cohortes , Régulation négative , Régulation de l'expression des gènes tumoraux , Cellules HEK293 , Immunohistochimie , Protéines et peptides de signalisation intercellulaire , Métabolisme , Estimation de Kaplan-Meier , Tumeurs du poumon , Génétique , Métabolisme , Anatomopathologie , Protéines de tissu nerveux , Métabolisme , Pronostic , Interférence par ARN , Récepteurs immunologiques , Métabolisme , RT-PCR , Transduction du signal , Génétique , Physiologie , Ubiquitin thiolesterase , Génétique , MétabolismeRésumé
AIM: To investigate the effect of nerve growth factor (NGF) on the proliferation of neural stem cell in adult rats with focal cerebral ischemia. METHODS: The experiment was conducted in the Center of Science and Experiment, Jinzhou Medical College from January to July 2006. Totally 72 healthy SD rats were randomly divided into sham-operation group, model group and NGF treatment group with 24 rats in each group. Focal cerebral ischemia models were prepared by Logna et al modified thread occlusion method, and the functional evaluation was performed after the animals were awake for 2 hours to select the rats whose nervous function reached grade 2 or above. The sham-operation group was treated like the model group except thread occlusion. 1 000 ?g/kg NGF was administered in the NGF treatment group immediately after ischemia, once a day. After the animals were executed at days 1, 3, 7 and 14 days, immunohistochemical and double immunofluorescence labeling were adopted to observe the effect of NGF on the expression of nestin and the cell type after ischemia. RESULTS: All 72 rats were involved in the result analysis. ①Round or ellipse nestin positive cells were found in both the model group and NGF treatment group. The number of nestin positive cells in the NGF treatment group was remarkably more than in model group except 1 day after ischemia, moreover, the number of the cells in the two groups was more than in the sham operation group [model group: (3.47?0.5), (5.13?1.14), (13.95?3.56), (8.97?2.08); NGF group: (3.81?0.66), (9.88?2.08), (19.87?3.86), (26.17?2.90); sham-operation group: 0, P
Résumé
Objective To investigate the effect of transplanted bone marrow stromal cells on the cells in the subventricular zone of the rats with permanent focal cerebral ischemia and analyze cell types.Methods Permanent focal cerebral ischemia models were established with middle cerebral artery occlusion(MCAO) and divided into three groups: MCAO alone,intravenous infusion of 1ml PBS at 24 hours after MCAO,and intravenous infusion of 2?106 BMSCs 24 hours after MCAO.Then,the groups were subdivided into 7-day and 14-day groups after MACO.Neurological functions were detected by Zausinger evaluation;meanwhile,5-bromodeoxyuridine was injected to label the proliferating cells in the subventricular zone,and double-immunofluscent technologies were used to identify the cell type.Results On the 7th day and the 14th day after MACO,neurological functional scores of BMSCs-treated group were higher than those of the other two groups(P