Background: Clonal competition in cancer describes the process in which the progeny of a cell clone supersedes or succumbs to other competing clones due to differences in their functional characteristics, mostly based on subsequently acquired mutations. Even though the patterns of those mutations are well explored in many tumors, the dynamical process of clonal selection is underexposed.
Methods: We studied the dynamics of clonal competition in a BcrAbl-induced leukemia using a γ-retroviral vector library encoding the oncogene in conjunction with genetic barcodes. To this end, we studied the growth dynamics of transduced cells on the clonal level both in vitro and in vivo in transplanted mice.
Results: While we detected moderate changes in clonal abundancies in vitro, we observed monoclonal leukemias in 6/30 mice after transplantation, which intriguingly were caused by only two different BcrAbl clones. To analyze the success of these clones, we applied a mathematical model of hematopoietic tissue maintenance, which indicated that a differential engraftment capacity of these two dominant clones provides a possible explanation of our observations. These findings were further supported by additional transplantation experiments and increased BcrAbl transcript levels in both clones.
Conclusion: Our findings show that clonal competition is not an absolute process based on mutations, but highly dependent on selection mechanisms in a given environmental context.
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http://dx.doi.org/10.1186/s12943-017-0668-x | DOI Listing |
Blood
March 2025
German Cancer Research Center, Heidelberg, Germany.
Donor blood saves lives, yet the potential impact of recurrent large-volume phlebotomy on donor health and hematopoietic stem cells (HSCs) remains largely unexplored. In our study, we conducted a comprehensive screening of 217 older male volunteer donors with a history of extensive blood donation (>100 life-time donations) to investigate the phenomenon of clonal hematopoiesis (CH). No significant difference in the overall incidence of CH was found in frequent donors (FD) compared to sporadic donors (<10 life-time donations, 212 donors).
View Article and Find Full Text PDFNat Commun
March 2025
Department of Medical Biophysics, Temerty Faculty of Medicine, University of Toronto, Toronto, M5G 1L7, Canada.
Ten-Eleven Translocation-2 (TET2) mutations drive the expansion of mutant hematopoietic stem cells (HSCs) in clonal hematopoiesis (CH). However, the precise mechanisms by which TET2 mutations confer a competitive advantage to HSCs remain unclear. Here, through an epigenetic drug screen, we discover that inhibition of disruptor of telomeric silencing 1-like (DOT1L), a H3K79 methyltransferase, selectively reduces the fitness of Tet2 knockout (Tet2) hematopoietic stem and progenitor cells (HSPCs).
View Article and Find Full Text PDFDiabetologia
March 2025
Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain.
The accumulation of acquired somatic mutations is a natural consequence of ageing, but the pathophysiological implications of these mutations beyond cancer are only beginning to be understood. Most somatic mutations are functionally neutral, but a few may confer a competitive advantage to a stem cell, driving its clonal expansion. When such a mutation arises in haematopoietic stem cells, it leads to clonal haematopoiesis, in which a significant proportion of blood cells originate from the mutant stem cell and share the same mutation.
View Article and Find Full Text PDFUnlabelled: Fanconi Anemia (FA) is a heritable syndrome characterized by DNA damage repair deficits, frequent malformations and a significantly elevated risk of bone marrow failure, leukemia, and mucosal head and neck squamous cell carcinomas (HNSCC). Hematopoietic stem cell gene therapy can prevent marrow failure and lower leukemia risk, but mucosal gene therapy to lower HNSCC risk remains untested. Major knowledge gaps include an incomplete understanding of how rapidly gene-corrected cellular lineages could spread through the oral epithelium, and which delivery parameters are critical for ensuring efficient gene correction.
View Article and Find Full Text PDFbioRxiv
February 2025
School of Biological Sciences, Georgia Institute of Technology. Atlanta, USA.
The evolutionary transition to multicellularity requires shifting the primary unit of selection from cells to multicellular collectives. How this occurs in aggregative organisms remains poorly understood. Clonal development provides a direct path to multicellular adaptation through genetic identity between cells, but aggregative organisms face a constraint: selection on collective-level traits cannot drive adaptation without positive genetic assortment.
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