编者按:第21届国际慢性淋巴细胞白血病研讨会(iwCLL 2025)于2025年9月12日~15日在波兰克拉科夫(Kraków)盛大召开。作为全球慢性淋巴细胞白血病(CLL)领域的顶尖学术盛会,iwCLL每两年举办一次,汇聚全球血液肿瘤领域的顶尖专家与学者,深入探讨CLL的前沿研究和治疗进展,推动学术创新与临床变革。在本次大会上,西班牙马德里12 de Octubre医院Alba Garrote de Barros博士口头报告的一项研究(摘要号:1023),探讨了MYC过表达对伴或不伴TP53功能缺失CLL的临床和生物学影响,为优化该类患者治疗提供了新的见解。《肿瘤瞭望-血液时讯》现场特邀Alba Garrote de Barros博士对其该研究进行深入解读。
《肿瘤瞭望-血液时讯》您的研究表明,TP53野生型患者中MYC过表达与较差的预后相关,而TP53受影响患者中的MYC过表达则未表现出显著的预后差异。您认为MYC过表达在不同TP53状态下的作用机制是如何不同的?这对临床治疗的个体化策略有何启示?
Alba Garrote de Barros博士:我们的研究显示,在TP53野生型背景下,MYC过表达与预后较差显著相关,相较于MYC低表达的患者,其临床结局更不理想。然而,在TP53突变背景下,MYC过表达似乎并未显著影响预后。在我们的细胞模型中亦观察到类似现象。这可能是由于TP53突变本身赋予了白血病细胞高度侵袭性的分子特征,从而掩盖了MYC过表达的潜在作用。
这一发现对临床实践具有重要意义,尤其是对于TP53野生型患者。尽管总体上该患者群体预后优于TP53突变患者,但其内部存在明显异质性。因此,需要对TP53野生型患者进行更精细化的分层研究,以进一步识别与不良预后相关的基因标志,为风险评估与个体化治疗提供依据。
Oncology Frontier-Hematology Frontier:Your study suggests that MYC overexpression correlates with worse prognosis in TP53 wild-type patients, while MYC overexpression in TP53-affected patients does not show significant prognostic differences. How do you think the role of MYC overexpression differs in the context of different TP53 statuses? What insights does this provide for personalized treatment strategies in clinical practice?
Dr. Alba Garrote de Barros:Our research demonstrates that, in the context of wild-type TP53, MYC overexpression is significantly associated with poorer prognosis compared to patients with low MYC expression, resulting in less favorable clinical outcomes. However, in the context of TP53 mutations, MYC overexpression does not appear to significantly impact prognosis. Similar findings were observed in our cellular models. This may be attributed to the inherently aggressive molecular characteristics conferred by TP53 mutations in leukemia cells, which likely overshadow the potential effects of MYC overexpression.
This finding holds significant implications for clinical practice, particularly for patients with wild-type TP53. Although this patient group generally exhibits a better prognosis than those with TP53 mutations, there is notable heterogeneity within this cohort. Therefore, more refined stratification studies are needed for wild-type TP53 patients to further identify genetic markers associated with adverse prognosis, providing a foundation for risk assessment and personalized treatment strategies.
《肿瘤瞭望-血液时讯》您的研究显示,MYC过表达在CLL细胞系中引起了多个生物学通路的失调,包括细胞周期调控和DNA修复通路。您认为这些通路的失调如何促进CLL的进展,特别是在Richter转化的背景下?
Alba Garrote de Barros博士:我们观察到,MYC过表达与基因失调及特定信号通路的富集密切相关。在TP53野生型患者中,MYC过表达主要上调并富集AKT通路;而在TP53突变患者中,MYC过表达则引起DNA修复通路的富集。基于此,我们推测MYC过表达与TP53破坏可能产生双重效应,即促进细胞增殖并增加基因组不稳定性,这可能与疾病进展及Richter转化相关。
然而,在TP53突变患者中,MYC过表达似乎并未显著影响预后或总生存期。这一结果超出了我们的预期——原本假设MYC过表达叠加TP53破坏会导致更差预后。但需注意的是,我们所测量的MYC转录水平取自治疗前样本。在治疗过程中,或在疾病演变中,可能会选择出MYC高表达的亚克隆,或者原有亚克隆的MYC表达水平增加,从而最终导致部分起初被归为MYC低表达的CLL患者转变为MYC高表达。此外,已有研究显示,MYC改变和扩增常存在于Richter转化的细胞中,且伴随TP53破坏。因此,这一机制或可解释为何我们在总生存期中未观察到预期的不良预后效应。
Oncology Frontier-Hematology Frontier:Your study shows that MYC overexpression induces dysregulation of several biological pathways, including cell cycle regulation and DNA repair pathways, in CLL cell lines. How do you think these dysregulated pathways contribute to the progression of CLL, especially in the context of Richter transformation?
Dr. Alba Garrote de Barros:We observed that MYC overexpression is closely associated with gene dysregulation and the enrichment of specific signaling pathways. In patients with wild-type TP53, MYC overexpression primarily upregulates and enriches the AKT pathway, whereas in patients with TP53 mutations, it leads to the enrichment of DNA repair pathways. Based on this, we hypothesize that MYC overexpression combined with TP53 disruption may exert a dual effect, promoting cell proliferation and increasing genomic instability, which could be linked to disease progression and Richter transformation.
However, in patients with TP53 mutations, MYC overexpression does not appear to significantly impact prognosis or overall survival. This result was unexpected, as we initially hypothesized that MYC overexpression coupled with TP53 disruption would lead to a worse prognosis. It should be noted, however, that the MYC transcription levels measured were obtained from pretreatment samples. During treatment or disease evolution, subclones with higher MYC expression may be selected, or the MYC expression levels in existing subclones may increase, ultimately leading some patients initially classified as having low MYC expression to transition to high MYC expression. Furthermore, existing studies indicate that MYC alterations and amplifications are frequently observed in cells undergoing Richter transformation, often accompanied by TP53 disruption. This mechanism may explain why we did not observe the anticipated adverse prognostic effect in our overall survival studies.
《肿瘤瞭望-血液时讯》研究中提到MYC过表达导致细胞增殖增加,尤其是在TP53野生型背景下。您是否考虑过将MYC过表达与其他已知的治疗耐药机制结合起来,例如BTK抑制剂耐药性?这一联合策略是否可能改善治疗效果?
Alba Garrote de Barros博士:在研究中,我们观察到MYC过表达与TP53破坏同时存在,可增强CLL细胞对伊布替尼和维奈托克的耐药性,这两种药物是目前CLL患者最常用的治疗方案。因此,我们认为有必要进一步探讨BTK抑制剂耐药的机制。此外,我们还计划研究更多在研药物,以解析在MYC过表达和TP53改变背景下BTK耐药性产生的原因。在蛋白质印迹实验中,我们未观察到AKT-mTOR通路的上调,由此推测BTK抑制剂的耐药可能涉及其他信号通路,而非PI3K-AKT-mTOR通路。因此,未来研究将重点关注可能与MYC相关、与DNA修复相关或涉及其他信号通路的潜在药物靶点。
Oncology Frontier-Hematology Frontier:Your research mentions that MYC overexpression leads to increased cell proliferation, especially in the TP53 wild-type background. Have you considered combining MYC overexpression with other known mechanisms of treatment resistance, such as BTK inhibitor resistance? Could this combined strategy potentially improve treatment outcomes?
Dr. Alba Garrote de Barros:In our study, we observed that the concurrent presence of MYC overexpression and TP53 disruption enhances the resistance of CLL cells to ibrutinib and venetoclax, which are currently the most commonly used treatments for CLL patients. Therefore, we believe it is necessary to further investigate the mechanisms underlying BTK inhibitor resistance. Additionally, we plan to explore more investigational drugs to elucidate the reasons for BTK resistance in the context of MYC overexpression and TP53 alterations. In Western blot experiments, we did not observe upregulation of the AKT-mTOR pathway, leading us to hypothesize that BTK inhibitor resistance may involve other signaling pathways rather than the PI3K-AKT-mTOR pathway. Consequently, future research will focus on potential drug targets related to MYC, DNA repair, or other signaling pathways.
研究简介
1023-MYC过表达对伴或不伴TP53功能缺失的慢性淋巴细胞白血病的临床和生物学影响
引言:MYC通路的激活以及TP53功能缺失是慢性淋巴细胞白血病(CLL)中公认的预后不良驱动因子,并且与Richter转化(RT)风险升高相关。尽管MYC过表达和TP53功能缺失各自发挥着重要作用,但MYC过表达和TP53功能缺失在CLL中的共存生物学后果以及两者如何共同促进RT的机制仍然不完全明了。本研究探讨了在TP53缺失与否的情况下MYC激活的临床和生物学影响,通过整合转录组分析和功能实验,分析了患者CLL样本和基因工程CLL细胞模型中的影响。
方法:研究分析了来自CLLmap数据库的566名CLL患者的临床和转录组数据。根据MYC表达使用MaxStat算法分组,并根据TP53缺失和/或突变的存在与否进一步分组。通过总生存期(OS)和首次治疗时间(TFT)评估这些改变的预后影响。此外,我们进行了差异表达基因(DEG)和功能富集分析(GSEA)。
我们使用CRISPR/Cas9-SAM基因组编辑技术,通过三种不同的sgRNA在两种CLL细胞系中构建MYC过表达(MYC-OE)的细胞模型:MEC1细胞系(具有TP53突变)和PGA细胞系(具有野生型TP53)。MYC-OE的验证通过蛋白质印迹、免疫荧光和qPCR完成。通过RNA-seq对转录组分析,评估MYC过表达对这两种细胞系的影响,随后进行了DEG和GSEA分析。通过蛋白质印迹、qPCR和细胞增殖实验进一步评估生物学机制。
结果:在TP53野生型(TP53-WT)患者组中,较高的MYC表达与较差的预后相关,包括OS和TFT(分别为P=0.006和P=0.018)。此外,TP53受影响(TP53-affected)/MYC-OE的CLL患者未显示出较短的OS或TFT。进一步地,TP53-WT/MYC-OE的CLL患者表现出的OS和TFT与TP53受影响的CLL患者相似。
从生物学角度来看,MYC过表达在这两种细胞系中引起了MYC靶基因的失调,这在患者中得到了观察,并通过qPCR在细胞模型中进一步验证(包括CCNE1、MCL1和NCL等)。此外,还发现了其他通路的失调,例如G2/M检查点、NF-κB和NOTCH信号通路。始终如一的是,MYC-OE细胞系(MEC1-TP53受影响/MYC-OE和PGA-TP53-WT/MYC-OE)显示出较野生型细胞更高的细胞增殖,尤其是在TP53-WT背景下表现更加显著。
此外,我们还揭示了Akt、mTOR和ERK的表达和激活差异,这可能与RNA-seq检测到的生物学通路改变和患者的预后相关。有趣的是,MEC1-TP53受影响/MYC-OE细胞系揭示了DNA修复通路的富集,这可能与RT相关的基因组不稳定性相关。
结论:TP53-WT和MYC-OE的CLL患者表现出比低MYC表达患者更差的预后,但与TP53受影响的患者的病程相似。这可能与患者和MYC-OE细胞模型中观察到的显著转录组变化有关,涉及的生物学通路和基因与细胞增殖增加相关。
专家简介
Alba Garrote de Barros博士
西班牙马德里12 de Octubre医院
西班牙马德里12 de Octubre医院临床研究所转化血液学系、H12O-CNIO血液恶性肿瘤临床研究组、CIBERONC肿瘤生物医学研究网络
Alba Garrote de Barros毕业于萨拉曼卡大学,获得生物学学士学位(2022),并于马德里康普顿斯大学(UCM)获得生物化学、分子生物学与生物医学硕士学位(2023)。她目前正在攻读博士学位,课题为《慢性淋巴细胞白血病及其Richter转化中并发基因改变与新型治疗靶点的影响》,该研究由PIPF-CAM 2023资助及课题组资源支持。她的研究在H12O/CNIO血液肿瘤组,由María Hernández博士、María Linares博士和Joaquín Martínez博士共同指导。