Do hematopoietic and LSCs share the same niche?
At diagnosis, most of the leukemic cells will be found in the BM or the blood, like the normal HSCs, and only in rare cases in non-hematopoietic organs. It is plausible that LSCs spread throughout the bone marrow and metastasize other sites there. Thus, they are able to escape the growth-inhibiting signals provided by the primary niche that maintain stem cell quiescence and prevent unlimited proliferation or self-renewal of normal HSCs. Recently, it has been shown that stem cells can home to vascular niches (28) and one can speculate that exactly these niches can serve as a home to the metastatic stem cells. Clearly, elucidating the localization of LSCs in the bone marrow and the identification of mechanisms by which LSCs escape the self-renewal cues of normal HSCs might provide a therapeutic window in which the LSC can specifically be targeted. The dissimilarities between normal and leukemic cells that potentially allow us to manipulate and specifically eliminate the leukemia most lik
