Despite the efficacy of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML), malignant long-term hematopoietic stem cells (LT-HSCs) persist as a source of relapse. However, LT-HSCs are heterogenous and the most primitive, drug-resistant LT-HSC subpopulations are not well characterized. In normal hematopoiesis, self-renewal and long-term reconstitution capacity are enriched within LT-HSCs with low c-Kit expression (c-KITlo). Here, using a transgenic CML mouse model, we found that long-term engraftment and leukemogenic capacity were restricted to c-KITlo CML LT-HSCs. CML LT-HSCs demonstrated enhanced differentiation with expansion of mature progeny following exposure to the c-KIT ligand, stem cell factor (SCF). Conversely, SCF deletion led to depletion of normal LT-HSCs but increase in c-KITlo and total CML LT-HSCs with reduced generation of mature myeloid cells. CML c-KITlo LT-HSCs showed reduced cell cycling and expressed enhanced quiescence and inflammatory gene signatures. SCF administration led to enhanced depletion of CML primitive progenitors but not LT-HSCs after TKI treatment. Human CML LT-HSCs with low or absent c-KIT expression were markedly enriched after TKI treatment. We conclude that CML LT-HSCs expressing low c-KIT levels are enriched for primitive, quiescent, drug-resistant leukemia-initiating cells and represent a critical target for eliminating disease persistence.
Mansi Shah, Harish Kumar, Shaowei Qiu, Hui Li, Mason Harris, Jianbo He, Ajay Abraham, David K. Crossman, Andrew Paterson, Robert S. Welner, Ravi Bhatia
Usage data is cumulative from November 2022 through February 2023.
Usage | JCI | PMC |
---|---|---|
Text version | 3,352 | 0 |
1,752 | 0 | |
Figure | 99 | 0 |
Supplemental data | 38 | 0 |
Citation downloads | 28 | 0 |
Totals | 5,269 | 0 |
Total Views | 5,269 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.