背景:IGH::DUX4在4%B细胞急性淋巴细胞白血病患者中经常观察到。关于IGH::DUX4驱动的反式激活和可变剪接,这是这次急性白血病爆发背后的主要原因,目前尚不清楚转录辅因子如何参与这一致癌过程.需要进一步研究以阐明它们在白血病发生中的特定作用。
方法:为了研究IGH::DUX4的辅因子,对白血病细胞和患者样本进行了染色质免疫沉淀(ChIP)测序和RNA测序的整合挖掘。此外,为了阐明转录因子12(TCF12)与IGH::DUX4之间的协同相互作用,哺乳动物双杂交试验,进行共免疫沉淀和原位邻近连接测定。此外,为了进一步研究TCF12和IGH::DUX4之间的直接相互作用,我们使用了基于AI的结构模拟。最后,为了验证TCF12在促进IGH::DUX4白血病中的协同作用,细胞增殖,进行细胞凋亡和药物敏感性实验。
结果:在这项研究中,我们观察到IGH::DUX4靶基因TCF12可能是该致癌驱动因子的重要辅因子/辅助因子。IGH::DUX4和TCF12的共表达导致DUX4驱动的反式激活增强。支持,TCF12的敲除和敲除显着降低了白血病REH(前体B细胞白血病细胞系)和NALM-6细胞(前体B细胞白血病细胞系)中IGH::DUX4驱动的靶基因的表达。始终如一,在TCF12敲除细胞中,基于结构的TCF12突变体的表达,但不是野生型TCF12,未能恢复TCF12-IGH::DUX4串扰和协同反式激活。更重要的是,TCF12-IGH::DUX4合作受损IGH::DUX4驱动的白血病细胞存活,导致对化疗的敏感性。
结论:总而言之,这些结果有助于在IGH::DUX4白血病中定义以前未被认可的TCF12介导的积极自我反馈调节机制,它具有作为治疗这种特殊形式的白血病的关键药物靶标的潜力。
结论:转录因子12(TCF12)是IGH::DUX4转录复合物/机制中一种新的辅因子。TCF12在IGH::DUX4驱动的致癌交易中介导积极的自我反馈调节机制。IGH::DUX4-TCF12结构/合作可能代表未来针对B细胞急性淋巴细胞白血病的药物设计的有效目标/方向。
IGH::DUX4 is frequently observed in 4% B-cell acute lymphoblastic leukaemia patients. Regarding the IGH::DUX4-driven transactivation and alternative splicing, which are the main reasons behind this acute leukaemia outbreak, it remains unclear how transcriptional cofactors contribute to this oncogenic process. Further investigation is required to elucidate their specific role in leukaemogenesis.
In order to investigate the cofactors of IGH::DUX4, integrated mining of Chromatin immunoprecipitation (ChIP)-sequencing and RNA-sequencing of leukaemia cells and patient samples were conducted. Furthermore, to elucidate the synergistic interaction between transcription factor 12 (TCF12) and IGH::DUX4, knockdown and knockout experiment, mammalian two-hybridisation assay, co-immunoprecipitation and in situ proximity ligation assays were carried out. Additionally, to further investigate the direct interaction between TCF12 and IGH::DUX4, AI-based structural simulations were utilised. Finally, to validate the synergistic role of TCF12 in promoting IGH::DUX4 leukaemia, cell proliferation, apoptosis and drug sensitivity experiments were performed.
In this study, we observed that the IGH::DUX4 target gene TCF12 might be an important cofactor/helper for this oncogenic driver. The co-expression of IGH::DUX4 and TCF12 resulted in enhanced DUX4-driven transactivation. Supportively, knockdown and knockout of TCF12 significantly reduced expression of IGH::DUX4-driven target genes in leukaemia REH (a precursor B-cell leukaemia cell line) and NALM-6 cells (a precursor B-cell leukaemia cell line). Consistently, in TCF12 knockout cells, the expression of structure-based TCF12 mutant, but not wild-type TCF12, failed to restore the TCF12-IGH::DUX4 crosstalk and the synergistic transactivation. More importantly, the breakdown in TCF12-IGH::DUX4 cooperation impaired IGH::DUX4-driven leukaemia cell survival, caused sensitivity to the chemotherapy.
Altogether, these results helped to define a previously unrecognised TCF12-mediated positive self-feedback regulatory mechanism in IGH::DUX4 leukaemia, which holds the potential to function as a pivotal drug target for the management of this particular form of leukaemia.
Transcription factor 12 (TCF12) is a new novel cofactor in IGH::DUX4 transcriptional complexes/machinery. TCF12 mediates a positive self-feedback regulatory mechanism in IGH::DUX4-driven oncogenic transaction. IGH::DUX4-TCF12 structure/cooperation might represent a potent target/direction in future drug design against B-cell acute lymphoblastic leukaemia.