PDF(Pubmed)
Abstract：
Activating variants in the PEST region of NOTCH1 have been associated with aggressive phenotypes in human cancers, including triple-negative breast cancer (TNBC). Previous studies suggested that PEST domain variants in TNBC patients resulted in increased cell proliferation, invasiveness, and decreased overall survival. In this study, we assess the phenotypic transformation of activating NOTCH1 variants and their response to standard of care therapies. AAV-mediated gene targeting was used to isogenically incorporate 3 NOTCH1 variants, including a novel TNBC frameshift variant, in two non-tumorigenic breast epithelial cell lines, MCF10A and hTERT-IMEC. Two different variants at the NOTCH1 A2241 site (A2441fs and A2441T) both demonstrated increased transformative properties when compared to a non-transformative PEST domain variant (S2523L). These phenotypic changes include proliferation, migration, anchorage-independent growth, and MAPK pathway activation. In contrast to previous studies, activating NOTCH1 variants did not display sensitivity to a gamma secretase inhibitor (GSI) or resistance to chemotherapies. This study demonstrates distinct transformative phenotypes are specific to a given variant within NOTCH1 and these phenotypes do not correlate with sensitivities or resistance to chemotherapies or GSIs. Although previous studies have suggested NOTCH1 variants may be prognostic for TNBC, our study does not demonstrate prognostic ability of these variants and suggests further characterization would be required for clinical applications.
摘要：
NOTCH1的PEST区域的激活变体与人类癌症中的侵袭性表型有关。包括三阴性乳腺癌（TNBC）。先前的研究表明，在TNBC患者中PEST结构域变异导致细胞增殖增加，侵入性,总体生存率下降。在这项研究中,我们评估了激活NOTCH1变异体的表型转化及其对标准治疗的反应.AAV介导的基因靶向用于同源掺入3个NOTCH1变体，包括一个新颖的TNBC移码变体，在两个非致瘤性乳腺上皮细胞系中，MCF10A和hTERT-IMEC。当与非转化性PEST结构域变体(S2523L)相比时,NOTCH1A2241位点处的两种不同变体(A2441fs和A2441T)均表现出增加的转化性质。这些表型变化包括增殖，迁移,锚定独立生长，和MAPK通路激活。与以前的研究相比，激活NOTCH1变异体未显示出对γ分泌酶抑制剂(GSI)的敏感性或对化疗的耐药性.这项研究表明，不同的转化表型对NOTCH1中的给定变体具有特异性，并且这些表型与对化学疗法或GSI的敏感性或抗性无关。尽管以前的研究表明NOTCH1变异可能是TNBC的预后因素，我们的研究未证明这些变异的预后能力,并提示临床应用需要进一步鉴定.
