Notch1 inhibition alters the CD44hi/CD24lo population and reduces the formation of brain metastases from breast cancer.
Notch1 inhibition alters the CD44hi/CD24lo population and reduces the formation of brain metastases from breast cancer.
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DOI：
10.1158/1541-7786.mcr-10-0457
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发表时间：
2011-07
期刊：
影响因子：
--
通讯作者：
Chambers AF
中科院分区：
文献类型：
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作者：
McGowan PM;Simedrea C;Ribot EJ;Foster PJ;Palmieri D;Steeg PS;Allan AL;Chambers AF
乳腺癌脑转移是一个日益重要的临床问题。在这里，我们评估了CD 44 hi/CD 24 lo细胞和调节它们的途径在脑转移实验模型中的作用。Notch信号传导（由γ-分泌酶介导）已显示有助于维持癌症干细胞（CSC）表型。与未分选的或CD 44 hi/CD 24 lo细胞相比，分选的干细胞样表型减少的细胞形成脑转移的能力降低（p<0.05; Kruskal沃利斯）。为了评估γ-分泌酶抑制的作用，将细胞与DAPT一起培养，并定量CD 44/CD 24表型。与DMSO处理或未处理细胞相比，DAPT处理细胞中具有CD 44 hi/CD 24 lo表型的231-BR细胞减少约15%（p = 0.001，ANOVA）。在体内，与溶剂处理或未处理的小鼠相比，用DAPT处理的小鼠发生的微小和巨大转移显著更少（p = 0.011，Kruskal沃利斯）。Notch 1敲低使CD 44 hi/CD 24 lo表型的表达降低约20%。在体外，NotchlshRNA导致在24小时、48小时和72小时时间点的细胞生长减少（p = 0.033、p = 0.002和p = 0.009，ANOVA），并且观察到Matrigel™侵袭减少约60%（p < 0.001，ANOVA）。与乱序shRNA或未转染的细胞相比，用shNotch 1转染的细胞形成显著更少的大转移和微转移（p < 0.001; Kruskal沃利斯）。这些数据表明，CSC表型有助于乳腺癌脑转移的发展，这可能部分源于Notch活性的增加。
Brain metastasis from breast cancer is an increasingly important clinical problem. Here we assessed the role of CD44hi/CD24lo cells and pathways that regulate them, in an experimental model of brain metastasis. Notch signaling (mediated by γ-secretase) has been shown to contribute to maintenance of the cancer stem cell (CSC) phenotype. Cells sorted for a reduced stem-like phenotype had a reduced ability to form brain metastases compared to unsorted or CD44hi/CD24lo cells (p<0.05; Kruskal Wallis). To assess the effect of γ-secretase inhibition, cells were cultured with DAPT and the CD44/CD24 phenotypes quantified. 231-BR cells with a CD44hi/CD24lo phenotype was reduced by ~15 % in cells treated with DAPT compared to DMSO-treated or untreated cells (p = 0.001, ANOVA). In vivo, mice treated with DAPT developed significantly fewer micro and macrometastases compared to vehicle treated or untreated mice (p = 0.011, Kruskal Wallis). Notch1 knockdown reduced the expression of CD44hi/CD24lo phenotype by ~20%. In vitro, Notch1 shRNA resulted in a reduction in cellular growth at 24 hour, 48 hour and 72 hour time points (p = 0.033, p = 0.002 and p = 0.009, ANOVA) and a ~60% reduction in Matrigel™ invasion was observed (p < 0.001, ANOVA). Cells transfected with shNotch1 formed significantly fewer macrometastases and micrometastases compared to scrambled shRNA or untransfected cells (p < 0.001; Kruskal Wallis). These data suggest that the CSC phenotype contributes to the development of brain metastases from breast cancer, and this may arise in part from increased Notch activity.