Here we report the characterization of a novel role for the retinoblastoma protein (pRb) as a regulator of osteoblast adhesion. Abrogation of pRb in osteoblasts resulted in aberrant cadherin expression and loss of adherens junctions. This produced defects suggestive of a transformed phenotype such as impaired cell-to-cell adhesion, loss of contact-dependent growth arrest, and the capacity to evade anoikis. This also resulted in profound abnormalities in bone structure. Consistent with this, microarray analyses showed that pRb regulates a wide repertoire of osteoblast cell adhesion genes. In addition, pRb loss also resulted in altered expression and function of several known regulators of cellular adhesion and adherens junction assembly, such as the Rho GTPase Rac1 and the merlin tumor suppressor. Taken together, our results show that pRb controls cell adhesion by regulating the expression and adherens junction components and by regulating the function of molecules involved in adherens junction assembly and stability.
A role for the retinoblastoma protein as a regulator of mouse osteoblast cell adhesion: implications for osteogenesis and osteosarcoma formation.
Specimen part
View SamplesWe report the expression anaysis of neural stem cells lacking p53, ATMIN, or both. p53-deficent cells form GBM, which is significanly delayed in the absence of ATMIN.
Inactivation of the ATMIN/ATM pathway protects against glioblastoma formation.
Specimen part
View SamplesThe OCT4 transcription factor is involved in many cellular processes, including development, reprogramming, maintaining pluripotency and differentiation. Synthetic OCT4 mRNA was recently used (in conjunction with other reprogramming factors) to generate human induced pluripotent stem cells. Here, we discovered that BAY 11-7082 (BAY11) could significantly increase the expression of OCT4 following transfection of synthetic mRNA (synRNA) into adult human skin cells. Importantly, the increased levels of OCT4 resulted in significantly increased expression of genes downstream of OCT4, including the previously identified SPP1, DUSP4 and GADD45G. We also identified a novel OCT4 downstream target gene SLC16A9 which demonstrated significantly increased expression following elevation of OCT4 levels. This small molecule-based stabilization of synthetic mRNA expression may have multiple applications for future cell-based research and therapeutics.
BAY11 enhances OCT4 synthetic mRNA expression in adult human skin cells.
Specimen part, Cell line, Treatment
View SamplesEffect of SDHB silencing using siRNA methodologies in the tumor phenotype
Cells silenced for SDHB expression display characteristic features of the tumor phenotype.
No sample metadata fields
View SamplesMicroarray analysis was performed on retina/RPE/choroid samples taken from the right eyes of male chicks across control and recovery from form deprivation conditions.
Pathway analysis identifies altered mitochondrial metabolism, neurotransmission, structural pathways and complement cascade in retina/RPE/ choroid in chick model of form-deprivation myopia.
Sex, Specimen part, Treatment, Time
View SamplesSpermatogonial stem cells are quiescent, undergo self-renewal or differentiating divisions, thereby forming the cellular basis of spermatogenesis. This cellular development is orchestrated by follicle-stimulating hormone (FSH), through the production of Sertoli cell-derived factors, and by Leydig cell-released androgens. Here, we investigate the transcriptional events induced by Fsh in a steroid-independent manner on the restart of zebrafish (Danio rerio) spermatogenesis ex vivo, using testis from adult males where type A spermatogonia were enriched by estrogen treatment in vivo. Under these conditions, RNA sequencing preferentially detected differentially expressed genes in somatic/Sertoli cells. Fsh-stimulated spermatogonial proliferation was accompanied by modulating several signaling systems (i.e. Tgf-ß, Hedgehog, Wnt and Notch pathways). In silico protein-protein interaction analysis indicated a role for Hedgehog family members potentially integrating signals from different pathways during fish spermatogenesis. Moreover, Fsh had a marked impact on metabolic genes, such as lactate and fatty acid metabolism, or on Sertoli cell barrier components. Fish Leydig cells express the Fsh receptor and one of the most robust Fsh-responsive genes was insulin-like 3 (insl3), a Leydig cell-derived growth factor. Follow-up work showed that recombinant zebrafish Insl3 mediated pro-differentiation effects of Fsh on spermatogonia in an androgen-independent manner. Our experimental approach allowed focusing on testicular somatic genes in zebrafish and showed that the activity of signaling systems known to be relevant in stem cell systems was modulated by Fsh, providing promising leads for future work, as exemplified by the studies on Insl3. Overall design: 12 samples in total were analyzed: 6 biological replicates from control testis samples and 6 biological replicates from Fsh-treated testis samples (all co-incubated with trilostane).
Expression profiling identifies Sertoli and Leydig cell genes as Fsh targets in adult zebrafish testis.
No sample metadata fields
View SamplesArabidopsis thaliana cells contain different O-acetylserine(thiol)lyase (OASTL) enzymes that catalyze the biosynthesis of cysteine. Recently, we have deeply investigated about one of the minor OASTL-like protein located in the cytosol, named DES1, highlighting some important clues about its metabolic function. We have demonstrated that DES1 catalyzes the desulfuration of L-cysteine to sulfide plus ammonia and pyruvate, instead of the biosynthesis of Cys, and thus, is a novel L-cysteine desulfhydrase (EC 4.4.1.1). The functionality of DES1 is being revealed by the phenotype of the T-DNA insertion mutants des1-1 and des1-2. We have performed a comparative transcriptomic analysis on leaves of the des1-1 and Col-0 wild type plants grown for 30 days under long-day conditions. The normalized data from the replicates showed differential expression of 1614 genes in the des1-1 mutant, with 701 genes down-regulated and 913 genes up-regulated by more than twofold, with a False Discovery Rate (FDR) of < 0.05 and an intensity signal restriction of lgSignal >7. This des1-1 transcriptional profile show a strong alteration when compared to a previous comparative transcriptomic analysis performed on leaves of the des1-1 and Col-0 wild type plants grown for 20 days under identical long-day conditions (GSE 19244). We have also performed a comparative transcriptomic analysis on leaves of the des1-1 and Col-0 wild type plants grown for 20 days and treated with sodium sulfide for 10 additional days. The comparison of the transcriptional profile of des1-1+Na2S versus Col-0+Na2S clearly shows that exogenous sulfide reversed the transcriptional level differences between the mutant and the wild type to reach similar transcriptional patterns as the array GSE19244. Our results suggest a role of sulfide as transcriptional regulator in the des1-1 mutant background.
Cysteine-generated sulfide in the cytosol negatively regulates autophagy and modulates the transcriptional profile in Arabidopsis.
Age, Specimen part, Treatment
View SamplesKruppel-like factors are a subclass of zinc finger transcription factors that play important roles in different aspects of cell growth, development, and differentiation. Our group have identified KLF13 as an essential transcription factor for the late expression of chemokine RANTES in T lymphocytes. However, very little is known about the role of KLF13 in T cells and other potential transcriptional targets. To address this, we sought to identify genes that are regulated by KLF13 in mouse T cells. Using microarray analysis, we compared gene expression in activated CD3+ T lymphocytes from wild type and Klf13-/- animals.
KLF13 cooperates with c-Maf to regulate IL-4 expression in CD4+ T cells.
Sex, Age, Specimen part
View SamplesMyeloproliferative neoplasms are frequently associated with aberrant constitutive tyrosine kinase (TK) activity resulting from point mutations or chimaeric fusion genes, such as BCR ABL1 or JAK2 V617F. We report here for the first time in hematological malignancies, two novel fusion genes involving the TK RET, BCR-RET and FGFR1OP-RET, in chronic myelo monocytic leukemia (CMML) cases. The two RET fusion genes lead to the aberrant activation of RET, are able to transform hematopoietic cells and skew the hematopoietic differentiation program towards the monocytic/macrophage lineage. We also report that the BCR-RET fusion protein is insensitive to Imatinib but sensitive to Sorafenib in vivo. CMML is an hematopoietic malignancy associated with the frequent activation of the RAS pathway. The RET fusion genes seems to constitutively mimic the same signaling pathway than RAS mutations. Overall, the RET fusion genes behaviors in the monocytic lineage underlie the role of the normal RET TK activity during the physiological monocytic differentiation.
RET fusion genes are associated with chronic myelomonocytic leukemia and enhance monocytic differentiation.
Cell line
View SamplesWe used microarrays to detail the global programme of gene expression upon the over-expression of seven different differentiation-associated, E1A-regulated microRNAs.
Differentiation-associated microRNAs antagonize the Rb-E2F pathway to restrict proliferation.
Cell line
View Samples