Single-Cell-Derived Primary Rectal Carcinoma Cell Lines Reflect Intratumor Heterogeneity Associated with Treatment Response.
Single-Cell-Derived Primary Rectal Carcinoma Cell Lines Reflect Intratumor Heterogeneity Associated with Treatment Response.
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DOI：
10.1158/1078-0432.ccr-19-1984
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发表时间：
2020-07-01
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影响因子：
--
通讯作者：
Ried T
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作者：
Braun R;Anthuber L;Hirsch D;Wangsa D;Lack J;McNeil NE;Heselmeyer-Haddad K;Torres I;Wangsa D;Brown MA;Tubbs A;Auslander N;Gertz EM;Brauer PR;Cam MC;Sackett DL;Habermann JK;Nussenzweig A;Ruppin E;Zhang Z;Rosenberg DW;Ried T
局部晚期直肠癌患者的标准治疗包括术前放化疗（CRT）和手术。然而，个体肿瘤对CRT的反应是极其多样的，呈现出临床困境。治疗反应的这种广泛变异性可能归因于肿瘤内异质性（ITH）。我们通过从异种移植后未经治疗的直肠癌活检中建立单细胞来源的细胞系（SCDCL），探讨了ITH对CRT反应的影响。来自同一肿瘤的个体SCDCL对体外CRT的反应截然不同。基于全外显子组测序的肿瘤和衍生细胞系的克隆重建揭示了在SCDCL中具有不同比例的9个独立簇。SV2A和ZWINT的错义突变在耐药SCDCL中是克隆性的，而在敏感SCDCL中未检测到。通过多重FISH的单细胞遗传分析揭示了在抗性SCDCL中具有PIK3CA缺失的克隆的扩增。通过tRNA测序的基因表达谱鉴定了耐药SCDCL中Wnt、Akt和Hedgehog信号通路的激活。使用报告基因测定证实了抗性SCDCL中的Wnt途径活化。我们的患者源性SCDCL模型系统为ITH在直肠癌患者治疗反应中的关键作用提供了证据，并表明不同的遗传畸变特征与治疗反应相关。我们确定了作为单个克隆治疗反应的分子基础的特定途径，其可以在异质性肿瘤的耐药亚克隆中靶向。
The standard treatment of patients with locally advanced rectal cancer consists of preoperative chemoradiotherapy (CRT) followed by surgery. However, the response of individual tumors to CRT is extremely diverse, presenting a clinical dilemma. This broad variability in treatment response is likely attributable to intratumor heterogeneity (ITH). We addressed the impact of ITH on response to CRT by establishing single-cell–derived cell lines (SCDCL) from a treatment-naïve rectal cancer biopsy after xenografting. Individual SCDCLs derived from the same tumor responded profoundly different to CRT in vitro. Clonal reconstruction of the tumor and derived cell lines based on whole-exome sequencing revealed nine separate clusters with distinct proportions in the SCDCLs. Missense mutations in SV2A and ZWINT were clonal in the resistant SCDCL, but not detected in the sensitive SCDCL. Single-cell genetic analysis by multiplex FISH revealed the expansion of a clone with a loss of PIK3CA in the resistant SCDCL. Gene expression profiling by tRNA-sequencing identified the activation of the Wnt, Akt, and Hedgehog signaling pathways in the resistant SCDCLs. Wnt pathway activation in the resistant SCDCLs was confirmed using a reporter assay. Our model system of patient-derived SCDCLs provides evidence for the critical role of ITH for treatment response in patients with rectal cancer and shows that distinct genetic aberration profiles are associated with treatment response. We identified specific pathways as the molecular basis of treatment response of individual clones, which could be targeted in resistant subclones of a heterogenous tumor.