a Interdisciplinary Health Sciences , University of Ottawa , Ottawa , Canada.
b Cellular and Molecular Medicine, Faculty of Medicine , University of Ottawa , Ottawa, Ontario , Canada.
Cancer Biol Ther. 2017 Oct 3;18(10):765-774. doi: 10.1080/15384047.2017.1373211. Epub 2017 Sep 8.
Many breast cancer patients use natural compounds in their battle against breast cancer. Active Hexose Correlated Compound (AHCC®) is a cultured mushroom mycelium extract shown to favorably modulate the immune system and alleviate cancer burden. Cancer Stem cells (CSCs) are a subset of highly tumorigenic cancer cells that are thought to be responsible for recurrence. CSCs can be epigenetically regulated by microRNAs (miRNAs). We hypothesized that AHCC may influence CSCs by modulating tumor-suppressor or oncogenic miRNAs.
Functionally-enriched stem and progenitor pools (FESPP) were isolated in the form of mammospheres from MDA-MB-231, MCF-7, and 4T1 cells, exposed to AHCC in both regular and primary culture from Balb/c mice, and analyzed by visual counting and flow cytometry. Cell motility was also observed in MDA-MB-231 cells. Profiling and RT-qPCR were performed to determine AHCC influence on miRNAs in MDA-MB-231 mammospheres. Additionally, Balb/c mice were orally gavaged with AHCC, and tumor growth parameters and miR-335 expression were analyzed. MDA-MB-231 cells were transfected with miR-335 and analyzed by western blot.
We demonstrated that AHCC reduced mammosphere growth in three cell lines and in primary culture, prevented cell migration, and upregulated miR-335 expression in MDA-MB-231 cells and mouse tumor samples. Among the differentially regulated miRNAs in CSCs, we focused on tumor suppressor miR-335, known to target extracellular matrix protein Tenascin C (TNC). TNC is involved in CSC immune evasion pathways. In MDA-MB-231, inhibition of miR-335 increased TNC protein expression.
These results support that AHCC limits FESPP growth, partly by targeting miRNA pathways.
许多乳腺癌患者在与乳腺癌的斗争中使用天然化合物。活性己糖相关化合物（AHCC®）是一种经过培养的蘑菇菌丝体提取物，已被证明可有效地调节免疫系统并减轻癌症负担。癌症干细胞（CSC）是一组具有高度致瘤性的癌细胞亚群，被认为是导致复发的原因。CSC 可以通过 microRNAs（miRNAs）的表观遗传调控。我们假设 AHCC 通过调节肿瘤抑制或致癌 miRNAs 来影响 CSC。
以 MDA-MB-231、MCF-7 和 4T1 细胞的类乳腺球体的形式分离功能富集的干细胞和祖细胞池（FESPP），在 Balb/c 小鼠的常规和原代培养中暴露于 AHCC，并通过视觉计数和流式细胞术进行分析。还观察了 MDA-MB-231 细胞的细胞迁移。进行了 miRNA 谱分析和 RT-qPCR，以确定 AHCC 对 MDA-MB-231 类乳腺球体中 miRNAs 的影响。此外，Balb/c 小鼠经口给予 AHCC，并分析肿瘤生长参数和 miR-335 表达。用 miR-335 转染 MDA-MB-231 细胞，并通过 Western blot 进行分析。
我们证明，AHCC 降低了三种细胞系和原代培养中的类乳腺球体生长，阻止了细胞迁移，并上调了 MDA-MB-231 细胞和小鼠肿瘤样本中的 miR-335 表达。在 CSC 中差异调节的 miRNAs 中，我们重点关注肿瘤抑制 miR-335，已知其靶向细胞外基质蛋白 Tenascin C（TNC）。TNC 参与 CSC 的免疫逃逸途径。在 MDA-MB-231 中，抑制 miR-335 增加了 TNC 蛋白表达。
这些结果支持 AHCC 通过靶向 miRNA 途径限制 FESPP 生长。
