Wang Lili, Shalek Alex K, Lawrence Mike, Ding Ruihua, Gaublomme Jellert T, Pochet Nathalie, Stojanov Petar, Sougnez Carrie, Shukla Sachet A, Stevenson Kristen E, Zhang Wandi, Wong Jessica, Sievers Quinlan L, MacDonald Bryan T, Vartanov Alexander R, Goldstein Natalie R, Neuberg Donna, He Xi, Lander Eric, Hacohen Nir, Regev Aviv, Getz Gad, Brown Jennifer R, Park Hongkun, Wu Catherine J
Cancer Vaccine Center, and Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA;
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA;
Blood. 2014 Aug 14;124(7):1089-98. doi: 10.1182/blood-2014-01-552067. Epub 2014 Apr 28.
One major goal of cancer genome sequencing is to identify key genes and pathways that drive tumor pathogenesis. Although many studies have identified candidate driver genes based on recurrence of mutations in individual genes, subsets of genes with nonrecurrent mutations may also be defined as putative drivers if they affect a single biological pathway. In this fashion, we previously identified Wnt signaling as significantly mutated through large-scale massively parallel DNA sequencing of chronic lymphocytic leukemia (CLL). Here, we use a novel method of biomolecule delivery, vertical silicon nanowires, to efficiently introduce small interfering RNAs into CLL cells, and interrogate the effects of 8 of 15 mutated Wnt pathway members identified across 91 CLLs. In HEK293T cells, mutations in 2 genes did not generate functional changes, 3 led to dysregulated pathway activation, and 3 led to further activation or loss of repression of pathway activation. Silencing 4 of 8 mutated genes in CLL samples harboring the mutated alleles resulted in reduced viability compared with leukemia samples with wild-type alleles. We demonstrate that somatic mutations in CLL can generate dependence on this pathway for survival. These findings support the notion that nonrecurrent mutations at different nodes of the Wnt pathway can contribute to leukemogenesis.
癌症基因组测序的一个主要目标是识别驱动肿瘤发病机制的关键基因和信号通路。尽管许多研究已基于单个基因中突变的复发情况鉴定出候选驱动基因，但如果具有非复发突变的基因子集影响单一生物信号通路，它们也可能被定义为假定驱动基因。通过这种方式，我们之前通过慢性淋巴细胞白血病（CLL）的大规模平行DNA测序发现Wnt信号通路存在显著突变。在此，我们使用一种新型生物分子递送方法——垂直硅纳米线，将小干扰RNA高效导入CLL细胞，并研究在91例CLL中鉴定出的15个突变的Wnt信号通路成员中的8个的作用。在HEK293T细胞中，2个基因的突变未产生功能变化，3个导致信号通路激活失调，3个导致信号通路激活进一步激活或抑制丧失。在携带突变等位基因的CLL样本中，沉默8个突变基因中的4个导致与具有野生型等位基因的白血病样本相比活力降低。我们证明CLL中的体细胞突变可导致对该信号通路的生存依赖。这些发现支持这样一种观点，即Wnt信号通路不同节点的非复发突变可促进白血病发生。
