PO.TB09.02 · 肿瘤生物学
量化癌基因成瘾性晚期非小细胞肺癌的进化动态和肿瘤异质性
Quantifying evolutionary dynamics and tumor heterogeneity in oncogene-addicted advanced non-small cell lung cancer
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
非小细胞肺癌(NSCLC)以癌基因成瘾为特征,其中独特的遗传学、表观遗传学和转录组学改变驱动肿瘤发生、生长和存活。针对可靶向癌基因的酪氨酸激酶抑制剂(TKI)显示出初步前景,但获得性耐药仍是重大临床挑战。为定义耐药和肿瘤异质性所依赖的进化动态,我们整合了来自104例患者(包括一个ALK重排队列)的1,253份纵向活检和多部位快速尸检的WES/WGS及RNA测序数据。我们开发了一个统一框架,结合前沿计算工具和新颖统计方法,以在TKI选择压力下刻画和量化肿瘤异质性。在2例对TKI获得性耐药的ALK重排病例中,我们鉴定出携带多个复合ALK突变的亚克隆。在pt062中,2个ALK双突变亚克隆共享一个祖先耐药突变C1156Y,并独立发展出继发性突变L1198F和I1171S,其中I1171S保留对Lorlatinib的部分敏感性,可能揭示了在完全耐药前的一个短暂治疗窗口。在pt992中,3个ALK双突变亚克隆共享一个原始突变F1193Y,并独立获得继发性突变G1269A、E1210K和G1210R,驱动对Crizotinib和Lorlatinib的差异性耐药。在pt992中,F1193Y可能是一种罕见的激活突变,单独不足以赋予对ALK TKI的耐药,但与继发性突变联合时促进耐药。系统发育分析揭示,pt062在疾病早期以单克隆播种为主,而pt992在耐药出现后为多克隆再播种。pt992中的转移路径推断提示,不同亚克隆的混合导致了携带三重ALK突变的病灶。由克隆多样性指数计算的瘤内异质性(ITH)显示,TKI暴露增加了ITH,产生病灶特异性亚克隆。在pt992中,G1202R+克隆的分化性克隆动态显示出比E1210K+克隆更低的ITH。奠基克隆在TKI治疗后分别以约50%(pt992)和85%(pt062)的肿瘤比例持续存在,表明选择压力不足。基于拷贝数改变和转录组的ITH提示原发与转移肿瘤之间克隆群体可能存在结构差异。瘤间异质性的Bray-Curtis相异度评分在两个病例中均揭示出3个聚类,提示转移病灶从特定亚克隆进化而来。通过CIBERSORT进行的RNA-seq免疫解卷积显示免疫细胞浸润模式各异,但与临床结局无相关性。这些结果表明TKI驱动癌基因成瘾性NSCLC中的克隆多样化和耐药进化,并为谱系指导的治疗策略提供了一个定量框架。
查看英文原文 English abstract
Non-small cell lung cancer (NSCLC) is characterized by oncogene addiction, where unique genetic, epigenetic, and transcriptomic alterations drive tumor initiation, growth, and survival. Tyrosine kinase inhibitors (TKIs) against actionable oncogenes showed initial promise, but acquired resistance remain significant clinical challenges. To define the evolutionary dynamics underlying resistance and tumor heterogeneity, we integrated WES/WGS and RNA sequencing data from 1,253 longitudinal biopsies and multi-site rapid autopsies from 104 patients, including an ALK-rearranged cohort. We developed a unified framework combining cutting-edge computational tools and novel statistical methods to characterize and quantify tumor heterogeneity under TKI selective pressure. In 2 ALK-rearranged cases with acquired resistance to TKIs, we identified subclones with multiple compound ALK mutations. In pt062, 2 ALK double-mutant subclones shared an ancestral resistance mutation C1156Y, and independently developed secondary hits L1198F and I1171S, where I1171S retains partial sensitivity to Lorlatinib, potentially revealing a transient therapeutic window before full resistance. In pt992, 3 ALK double-mutant subclones shared an original mutation F1193Y, and independently acquired secondary hits G1269A, E1210K, and G1210R, driving differential resistance to Crizotinib and Lorlatinib. In pt992, F1193Y may be a rare activating mutation that is insufficient to confer resistance to ALK TKIs alone, but promoted resistance in combination with secondary hits. Phylogenetic analysis revealed predominantly monoclonal seeding early in disease in pt062 vs polyclonal reseeding after the emergence of resistance in pt992. Metastatic route inference in pt992 suggests that a mix of distinct subclones result in lesions with triple ALK mutations. Intra-tumor heterogeneity (ITH) calculated from the clonal diversity index revealed that TKI exposure increased ITH, resulting in lesion-specific subclones. In pt992, divergent clonal dynamics in G1202R+ clones showed lower ITH than E1210K+ clones. The founding clones persisted at ~50% (pt992) and 85% (pt062) tumor fraction post-TKI, indicating inadequate selective pressure. Copy number alteration- and transcriptomic-based ITH suggest possible structural differences in clonal populations between primary and metastatic tumors. Bray-Curtis dissimilarity scores of inter-tumor heterogeneity revealed 3 clusters in both cases, suggesting that metastatic lesions evolved from specific subclones. RNA-seq immune deconvolution via CIBERSORT showed variable immune cell infiltration patterns without correlation to clinical outcome. These results demonstrate that TKIs drive clonal diversification and evolution of resistance in oncogene-addicted NSCLC, and offer a quantitative framework for lineage-informed therapeutic strategies.
利益披露 Disclosure
L. C. Etienne, None..
E. E. Martin, None..
P. Eser, None..
K. Pontious, None..
J. Tsuji, None..
N. Lytell, None..
N. Chevalier, None..
M. Banwait, None..
J. L. Peterson, None..
M. S. Lawrence, None..
M. Mino-Kenudsen, None..
J. J. Lin, None..
Z. Piotrowska, None..
R. Heist, None..
D. Juric, None..
J. Gainor, None.