Project description:MYSM1 is a transcriptional regulator essential for HSC function and hematopoiesis. We established that p53 activation is a common mechanism mediating HSC dysfunction, MPP depletion, and lymphopenia in Mysm1-deficiency, however, the specific p53-induced effectors that trigger dysfunction in Mysm1-deficient HSPCs remain unknown. Here, we performed RNA-Seq of Lin-cKit+Sca1+CD150+ and CD150- HSPCs from Mysm1-/-Puma-/-, Mysm1-/-Puma+/-, Puma-/-, and wild-type mice; (Mysm1-/-Puma+/- phenocopies Mysm1-/-). We showed that Bbc3/PUMA is the primary non-redundant mediator of MPP depletion in Mysm1-deficiency and contributes to HSC dysfunction, whereas depletion of lymphoid-lineage cells involves PUMA-independent p53 activities. We also identified a broad downregulation of genes encoding protein components of the ribosome (RP-genes) and other regulators of translation in Mysm1-deficiency, and the downregulation persisted in Mysm1-/-Puma-/-.

2020-07-22 | GSE150665 | GEO

Synthetical lethality of Werner helicase and mismatch repair deficiency is mediated by p53 and PUMA in colon cancer

Project description:Synthetic lethality is a powerful approach for targeting oncogenic drivers in cancer. Recent studies revealed that cancer cells with microsatellite instability (MSI) require Werner (WRN) helicase for survival; however, the underlying mechanism remains unclear. In this study, we found that WRN depletion strongly induced p53 and its downstream apoptotic target PUMA in MSI colorectal cancer (CRC) cells. p53 or PUMA deletion abolished apoptosis induced by WRN depletion in MSI CRC cells. Importantly, correction of MSI abrogated the activation of p53/PUMA and cell killing, while induction of MSI led to sensitivity in isogenic CRC cells. Rare p53-mutant MSI CRC cells are resistant to WRN depletion due to lack of PUMA induction, which could be restored by wildtype p53 knock-in or reconstitution. WRN depletion or treatment with the RecQ helicase inhibitor ML216 suppressed in vitro and in vivo growth of MSI CRCs in a p53/PUMA_x0002_dependent manner. ML216 treatment was efficacious in MSI CRC patient-derived xenografts (PDX). Interestingly, p53 gene remains wildtype in the majority of MSI CRCs. These results indicate a critical role of p53/PUMA-mediated apoptosis in the vulnerability of MSI CRCs to WRN loss, and support WRN as a promising therapeutic target in p53-wildtype MSI CRCs.

2022-10-26 | GSE216455 | GEO

Combined absence of Trp53 target genes Zmat3, Puma and p21 cause a high incidence of cancer in mice

Project description:Transcriptional activation of target genes is essential for TP53-mediated tumour suppression, though the roles of the diverse TP53-activated target genes in tumour suppression remains poorly understood. Knockdown of Zmat3, an RNA-binding zinc-finger protein involved in regulating alternative splicing, in haematopoietic cells by shRNA caused leukaemia only with the concomitant absence of the Puma and p21, the critical effectors of Trp53-mediated apoptosis and cell cycle arrest respectively. We were interested to further investigate the role of ZMAT3 in tumour suppression beyond the haematopoietic system. Therefore, we generated Zmat3 knockout and compound gene knockout mice, lacking Zmat3 and p21, Zmat3 and Puma or all three genes. Puma-/-p21-/-Zmat3-/- triple knockout mice developed tumours at a significantly higher frequency compared to wild-type, Puma-/-Zmat3-/- or p21-/-Zmat3-/-deficient mice. Interestingly, we observed that the triple knockout and Puma-/-Zmat3-/- double deficient animals succumbed to lymphoma, while p21-/-Zmat3-/- animals developed mainly solid cancers. This analysis suggests that in addition to ZMAT3 loss, additional TRP53-regulated processes must be disabled simultaneously for TRP53-mediated tumour suppression to fail. Our findings reveal that the absence of different TRP53 regulated tumour suppressive processes changes the tumour spectrum, indicating that different TRP53 tumour suppressive pathways are more critical in different tissues.

2023-11-28 | GSE248747 | GEO

Puma concolor isolate:SC36

Project description:Complete de novo genome & assembly of the mountain lion (puma)

| PRJNA437459 | ENA