Project description:It is now well established that members of the homeobox gene family play a critical role in normal hematopoietic cell development and that their unbalanced or ectopic expression can lead to characteristic perturbations in haemopoiesis and the onset of leukaemia. TLX3 expression in human haematologic malignancies is exclusive to T-ALL, where it is almost universally associated with transformation of early cortical CD4+CD8+ DP thymocytes. investigated the impact of ectopic TLX3 expression on T cell development, and the initiating mechanisms of T-cell transformation leading to leukemia onset. Forced expression of TLX3 disrupted the thymic develoment at DN-like stage giving rise to immortalized preleukemic clones.
Project description:Here we performed a ChIP-seq experiment for Tlx3 trancription factor on a sample of mouse embryonic dorsal spinal cord. The result is the generation of the genome-wide maps for Tlx3 binding to chromatin in dILB neurones of the developing dorsal horn.
Project description:Estrogen Receptor alpha (ERα) is a key driver of most breast cancers, and it is the target of endocrine therapies used in the clinic to treat women with ERα positive (ER+) breast cancer. The two methods ChIP-seq (chromatin immunoprecipitation coupled with deep sequencing) and RIME (Rapid Immunoprecipitation of Endogenous Proteins) have greatly improved our understanding of ERα function during breast cancer progression and in response to anti-estrogens. A critical component of both ChIP-seq and RIME protocols is the antibody that is used to pull down the bait protein. To date, most of the ChIP-seq and RIME experiments for the study of ERα have been performed using the sc-543 antibody from Santa Cruz Biotechnology. However, this antibody has been discontinued, thereby severely impacting the study of ERα in normal physiology as well as diseases such as breast cancer and ovarian cancer. Here, we compare the sc-543 antibody with other commercially available antibodies, and we show that 06-935 (EMD Millipore) and ab3575 (Abcam) antibodies can successfully replace the sc-543 antibody for ChIP-seq and RIME experiments.
Project description:T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematological disease originating from the malignant transformation of T-cell progenitors caused by the accumulation of genetic aberrations. One fifth of T-ALL patients are characterized by the ectopic expression of the homeobox transcription factor TLX3, which is normally not expressed in hematopoietic cells. Strikingly, this TLX3 positive subgroup of T-ALL has a high frequency of FLT3 mutations. Co-expression of TLX3 and FLT3-ITD in ex vivo pro-T cells conferred IL7 independent growth, confirming that TLX3 expression and FLT3 signaling cooperate to transform T-cells and make them less dependent on extracellular signals. After inducing TLX3 expression for 24 hours in Pro-T cells, transducin-like enhancer of split 4 (Tle4) was detected to be downregulated. Interestingly, T-ALL patients also present a strongly decreased expression of TLE4 specific to TLX3 and TLX1 subtypes. Family members of the transcriptional corepressor TLE4 have been described to interact and thus, inhibit transcription factors, through their interaction with an Engrailed-homology 1 (Eh1) domain. Generation of a point mutation in the Eh1 domain present at the N-terminus of TLX3 allowed us to show that TLE4 has a repressive effect on TLX3 activity. Together, we propose a TLX3+FLT3-ITD Pro-T cell model and use this to illustrate that low expression levels of TLE4 are favourable for the oncogenic function of TLX3.
Project description:Homeobox gene Tlx3 is known to promote glutamatergic differentiation and is expressed in post-mitotic neurons of CNS. Contrary to this here, we discovered that Tlx3 is expressed in the proliferating progenitors of the external granule layer in the cerebellum, and examined factors that regulate this expression. Using Pax6-/-Sey mouse model and molecular interaction studies we demonstrate Pax6 is a key activator of Tlx3 specifically in cerebellum, and induces its expression starting at embryonic day (E)15. By Postnatal day (PN)7, Tlx3 is expressed in a highly restricted manner in the cerebellar granule neurons of the posterior cerebellar lobes, where it is required for the restricted expression of nicotinic cholinergic receptor-α3 subunit (Chrnα3) and other genes involved in formation of synaptic connections and neuronal migration. These results demonstrate a novel role for Tlx3 and indicate that Pax6-Tlx3 expression and interaction is part of a region specific regulatory network in cerebellum and its deregulation during development could possibly lead to Autistic spectral disorders (ASD) Anterior and posterior lobes of PN7 mouse cerebellum were isolated separately and differentially expressed genes were identified.