Epithelial-mesenchymal transition in haematopoietic stem cell development and homeostasis.

October 1 2018

Review paper

Hamidi S, Sheng G.

J Biochem. 2018 Oct 1;164(4):265-275. doi: 10.1093/jb/mvy063. Review.

In simple language:
Given the role of EMT master regulators in normal and pathologic hematopoiesis, Dr. Sofiane Hamidi in Prof. Guojun Sheng's lab hypothesized that a unicellular EMT/MET process is involved in the maintenance of HSC homeostasis through its interactions with other cellular components in the niche.

Review summary:
Epithelial-mesenchymal transition (EMT) is a morphogenetic process of cells that adopt an epithelial organization in their developmental ontogeny or homeostatic maintenance. Abnormalities in EMT regulation result in many malignant tumours in the human body. Tumours associated with the haematopoietic system, however, are traditionally not considered to involve EMT and haematopoietic stem cells (HSCs) are generally not associated with epithelial characteristics. In this review, we discuss the ontogeny and homeostasis of adult HSCs in the context of EMT intermediate states. We provide evidence that cell polarity regulation is critical for both HSC formation from embryonic dorsal aorta and HSC self-renewal and differentiation in adult bone marrow. HSC polarity is controlled by the same set of surface and transcriptional regulators as those described in canonical EMT processes. With an emphasis on partial EMT, we propose that the concept of EMT can be similarly applied in the study of HSC generation, maintenance and pathogenesis.