Adam W. Beck, Yichen Guo, Herbert Chen, Qiming Jane Wang, Qi Cao, Jinjin Hao, Helen Krontiras, Rachael Guenter, Roy L. Silverstein, Justin D. Lathia, Bin Ren, Reagan Hattaway, Yinan Jiang, Douglas R. Hurst, and Yehe Liu
Breast cancer stem cells (BCSCs) are essential for cancer growth, metastasis and recurrence. The regulatory mechanisms of BCSC interactions with the vascular niche within the tumor microenvironment (TME) and their self-renewal are currently under extensive investigation. We have demonstrated the existence of an arteriolar niche in the TME of human BC tissues. Intriguingly, BCSCs tend to be enriched within the arteriolar niche in human estrogen receptor positive (ER+) BC and bi-directionally interact with arteriolar endothelial cells (ECs). Mechanistically, this interaction is driven by the lysophosphatidic acid (LPA)/protein kinase D (PKD-1) signaling pathway, which promotes both arteriolar differentiation of ECs and self-renewal of CSCs likely via differential regulation of CD36 transcription. This study indicates that CSCs may enjoy blood perfusion to maintain their stemness features. Targeting the LPA/PKD-1 -CD36 signaling pathway may have therapeutic potential to curb tumor progression by disrupting the arteriolar niche and effectively eliminating CSCs., Jiang, Guo, Hao et al. investigate the role of the tumour microenvironment in breast cancer stem cell regulation and identify an arteriolar niche in which BCSCs tended to be enriched in human estrogen receptor positive breast cancer. Here, BCSCs are found to interact with arteriolar endothelial cells through LPA/PKD-1 signalling-mediated arteriolar differentiation of ECs and self-renewal of BCSCs.