Shanghai Cancer Center & Institutes of Biomedical Sciences, Cancer Institute, Key Laboratory of Breast Cancer in Shanghai, Key Laboratory of Medical Epigenetics and Metabolism, Innovation Center for Cell Signaling Network, Shanghai Medical College, Fudan University, Shanghai 200032, China.
School of Life Science, University of Science & Technology of China, Hefei, Anhui 230027, China.
Theranostics. 2018 Nov 10;8(21):5801-5813. doi: 10.7150/thno.29380. eCollection 2018.
Increasing evidence demonstrates the existence of two inter-convertible states of breast cancer stem cells (BCSCs) with distinct behaviors in proliferation and mobility, and the BCSC heterogeneity is accurately regulated by sophisticated mechanisms including microRNAs. The microRNA-200 family including miR-200c/141 cluster was reported to affect cancer cell invasion and metastasis by regulating epithelial to mesenchymal transition (EMT). However, the effect of miR-200 family on BCSC heterogeneity is uncertain. Thus, we investigated whether the miR-200c/141 cluster had different effects on breast tumor growth and metastasis by switching the two states of BCSC. : The spontaneous mammary tumor mouse model with miR-200c/141 conditional knockout was utilized for analyzing the role of miR-200c/141 cluster . The effect of miR-200c/141 cluster on BCSCs was performed by CD24/CD29 staining and ALDEFLUOR assay. miR-200c/141 target expression and EMT-related marker expression were verified in tumor sections, primary cells and breast cancer cell lines by qRT-PCR or western blotting. Statistical analysis was determined using two-way ANOVA and Student's t-test. All values were presented as the mean ± s.e.m. : The deletion of miR-200c/141 cluster regulated BCSC heterogeneity and promoted the EMT-like BCSC generation, which resulted in increased tumor metastasis and inhibited tumor growth by directly upregulating the target gene homeodomain-interacting protein kinase 1 (HIPK1) and sequential β-catenin activation. : Our results indicated that miR-200c/141 played biphasic roles in breast tumor progression via affecting the BCSC heterogeneity, suggesting targeting BCSC heterogeneity to simultaneously restrict breast cancer initiation and metastasis could be a promising therapeutic strategy for breast cancer.
越来越多的证据表明，乳腺癌干细胞（BCSCs）存在两种可相互转化的状态，其增殖和迁移行为不同，BCSC 异质性受包括 microRNA 在内的复杂机制精确调控。microRNA-200 家族（包括 miR-200c/141 簇）被报道通过调节上皮间质转化（EMT）来影响癌细胞的侵袭和转移。然而，miR-200 家族对 BCSC 异质性的影响尚不确定。因此，我们研究了 miR-200c/141 簇是否通过切换 BCSC 的两种状态对乳腺癌肿瘤生长和转移产生不同的影响。
利用 miR-200c/141 条件性敲除的自发乳腺肿瘤小鼠模型分析 miR-200c/141 簇的作用。通过 CD24/CD29 染色和 ALDEFLUOR 检测分析 miR-200c/141 簇对 BCSC 的影响。通过 qRT-PCR 或 Western blot 在肿瘤切片、原代细胞和乳腺癌细胞系中验证 miR-200c/141 簇的靶基因表达和 EMT 相关标志物表达。采用双向方差分析和 Student's t 检验进行统计学分析。所有数值均表示为平均值±s.e.m.
miR-200c/141 簇缺失调节 BCSC 异质性并促进 EMT 样 BCSC 生成，从而通过直接上调靶基因同源结构域相互作用蛋白激酶 1（HIPK1）和顺序β-连环蛋白激活，增加肿瘤转移并抑制肿瘤生长。
我们的研究结果表明，miR-200c/141 通过影响 BCSC 异质性在乳腺肿瘤进展中发挥双重作用，提示靶向 BCSC 异质性，同时限制乳腺癌的起始和转移，可能是治疗乳腺癌的一种有前途的策略。
