Kaller Markus, Forné Ignasi, Imhof Axel, Hermeking Heiko
Experimental and Molecular Pathology, Institute of Pathology, Faculty of Medicine, Ludwig-Maximilians-Universität München, Thalkirchner Strasse 36, D-80337 Munich, Germany.
BioMedical Center, Faculty of Medicine, Ludwig-Maximilians-Universität München, Grosshaderner Strasse 9, D-82152 Planegg-Martinsried, Germany.
Cancers (Basel). 2024 Apr 24;16(9):1639. doi: 10.3390/cancers16091639.
Loss of the p53-inducible in p53-proficient CRC cell lines results in increased sensitivity to DNA-damaging chemotherapeutics. Here, we comprehensively analyze how affects the p53-induced transcriptional program.
Using a CRISPR/Cas9-approach, we deleted the p53 binding site in the promoter of SW480 colorectal cancer cells and subjected them to RNA-Seq analysis after the activation of ectopic p53. RNA affinity purification followed by mass spectrometry was used to identify proteins associated with .
Loss of the p53-inducibility of resulted in an ~1.8-fold increase in the number of significantly regulated mRNAs compared to wild-type cells after ectopic activation of p53. A subset of direct p53 target genes, such as and displayed significantly stronger induction when the p53-inducibility of was abrogated. Loss of the p53-inducibility of resulted in alternative splicing of a small number of mRNAs, such as , , and . Several RNA binding proteins involved in pre-mRNA splicing were identified as interaction partners of by mass spectrometry.
Our results suggest that may restrict the extent and strength of p53-mediated transcriptional changes via context-dependent regulation of the expression and splicing of a subset of p53-regulated genes.
在p53功能正常的结直肠癌（CRC）细胞系中，p53诱导型[蛋白名称未给出]的缺失导致对DNA损伤化疗药物的敏感性增加。在此，我们全面分析了[蛋白名称未给出]如何影响p53诱导的转录程序。
使用CRISPR/Cas9方法，我们删除了SW480结肠癌细胞[蛋白名称未给出]启动子中的p53结合位点，并在异位激活p53后对其进行RNA测序分析。采用RNA亲和纯化结合质谱法来鉴定与[蛋白名称未给出]相关的蛋白质。
与野生型细胞相比，在异位激活p53后，[蛋白名称未给出]的p53诱导性缺失导致显著调控的mRNA数量增加了约1.8倍。当[蛋白名称未给出]的p53诱导性被消除时，一部分直接的p53靶基因，如[基因名称未给出]和[基因名称未给出]表现出显著更强的诱导作用。[蛋白名称未给出]的p53诱导性缺失导致少数mRNA发生可变剪接，如[基因名称未给出]、[基因名称未给出]和[基因名称未给出]。通过质谱法鉴定出几种参与前体mRNA剪接的RNA结合蛋白是[蛋白名称未给出]的相互作用伙伴。
我们的结果表明，[蛋白名称未给出]可能通过对p53调控基因子集的表达和剪接进行上下文依赖性调节，来限制p53介导的转录变化的程度和强度。
