Project description:We observed that the deletion of Anp32b led to severe defects in ocular development, such as anophthalmia and microphthalmia. Moreover, Anp32b was highly expressed in the lens, and Anp32b−/− embryos with microphthalmia typically exhibited severely impaired lens development. Mechanistically, ANP32B directly interacted with paired box protein 6 (PAX6), a master transcriptional regulator of ocular development, and enhanced its transcriptional activity. In line with these findings, overexpression of PAX6 partially but significantly reversed the inhibition of proliferation observed in ANP32B knockdown cells. Collectively, our findings reveal that ANP32B-deficiency suppresses ocular development by repression of PAX6 and identify ANP32B as a viable therapeutic target for ocular developmental defects.
Project description:The acidic leucine-rich nuclear phosphoprotein 32B (ANP32B) is critical for maintenance of normal and leukemia stem cells. However, no data exist on ANP32B requirement in B-cell acute lymphoblastic leukemia (B-ALL) progression. Here, we observe that ANP32B is lowly expressed in B-ALL patients, which correlates with poor prognosis. Furthermore, we utilize N-myc or BCR-ABLp190-induced B-ALL mouse model to investigate the role of ANP32B in B-ALL development. Intriguingly, conditional deletion of Anp32b in hematopoietic cells significantly promotes leukemogenesis in B-ALL. Mechanistically, ANP32B interacts with PU.1 and enhances the transcriptional activity of PU.1 in B-ALL cells. Overexpression of PU.1 dramatically suppresses B-ALL progression, and highly expressed PU.1 significantly reverses the accelerated leukemogenesis in Anp32b-deficient mice. Collectively, our findings firstly identify ANP32B as a suppressor gene and provide novel insight into B-ALL pathogenesis.
Project description:we demonstrate that conditional deletion of acidic leucine-rich nuclear phosphoprotein 32B (ANP32B) in hematopoietic cells impairs repopulation capacity and postinjury regeneration of HSCs. Mechanistically, ANP32B forms a repressive complex with and thus inhibits the transcriptional activity of p53 in hematopoietic cells, and p53 deletion rescues the functional defect in Anp32b-deficient HSCs. Of great interest, ANP32B is highly expressed in leukemic cells from patients with chronic myelogenous leukemia (CML). Anp32b deletion enhances p53 transcriptional activity to impair LSC function in a murine CML model and exhibits synergistic therapeutic effects with tyrosine kinase inhibitors in inhibiting CML propagation. In summary, our findings provide a novel strategy to enhance p53 activity in LSCs by inhibiting ANP32B and identify ANP32B as a potential therapeutic target in treating CML.
Project description:The homeobox-containing transcription factor PAX6 is a key regulator of eye development. Pathogenic heterozygous PAX6 variants lead to variable ocular phenotypes. Missense variants are often associated with milder ocular conditions, although variants in the DNA-binding paired domain which alter target binding lead to severe ocular phenotypes including bilateral microphthalmia, similar to SOX2 anophthalmia syndrome. However, the variant-specific pathway disruption resulting in phenotypic heterogeneity is not well understood.
Project description:The homeobox-containing transcription factor PAX6 is a key regulator of eye development. Pathogenic heterozygous PAX6 variants lead to variable ocular phenotypes. Missense variants are often associated with milder ocular conditions, although variants in the DNA-binding paired domain which alter target binding lead to severe ocular phenotypes including bilateral microphthalmia, similar to SOX2 anophthalmia syndrome. However, the variant-specific pathway disruption resulting in phenotypic heterogeneity is not well understood.