26.03.2021: In a recently published study in Blood Advances, a research team from the Institute of Pharmacology and Toxicology at Vetmeduni describes the optimized generation of mouse cell lines (HPCLSK) that reliably mimic haematopoietic/leukaemic progenitor cells. According to the researchers, the new HPCLSK system represents a unique tool for combined in vitro and in vivo studies and is of high clinical relevance, as the new method allows experiments in stem cells. A better understanding of leukaemic stem cells is of fundamental importance for the development of new cancer therapies.
Functional and molecular studies on haematopoietic stem cells (HSCs) and leukaemic stem cells (LSCs) have provided numerous insights into the mechanisms of haematopoietic diseases. However, progress is restricted by a small number of stem cells and progenitor cells that imitate the situation in vivo. An optimized solution is now available, thanks to Eszter Doma and Isabella Mayer from the Institute of Pharmacology and Toxicology at Vetmeduni. The HPCLSK system represents a unique tool for combined in vitro and in vivo studies and enables the production of large quantities of genetically modifiable stem/progenitor cells (LSK cells). According to the researchers, the data from their study show that the results of HPCLSK experiments can be transferred to the human situation. “There is already great international interest in the newly developed method. It has already been applied and published by another research group from Helsinki," says co-first author Isabella Mayer.
Generation of functional haematopoietic progenitor cell lines
The researchers present a robust procedure to generate an unlimited source of functional mouse HSC/HPC lines called HPCLSK that possess characteristics of multipotent cells (MPP) and can serve as a source of lymphoid and myeloid LSC lines because they retain lymphoid and myeloid differentiation potential. “We have developed a reliable method to generate and maintain LSK (Lin–, Sca-1+, c-Kit+) cells, which closely resemble MPP1 cells. HPCLSKs reconstitute haematopoiesis in lethally irradiated recipient mice. Upon transformation with different oncogenes, including BCR/ABL, FLT3-ITD or MLL-AF9, their leukaemic counterparts maintain stem cell properties in vitro and recapitulate leukaemia formation in vivo,” says first author Eszter Doma.
New role of CDK6 discovered
The method to generate HPCLSKs can be applied to transgenic mice and is illustrated by the researchers in their study using animals with a missing CDK6 function. Upon BCR/ABLp210 transformation, HPCLSKs CDK6–/– induced disease with a significantly enhanced latency and reduced incidence, showing the importance of CDK6 in leukaemia formation. Studies of the CDK6 transcriptome in murine HPCLSK and human BCR/ABL+ cells have verified that certain pathways depend on CDK6 and have uncovered a novel CDK6-dependent signature, suggesting a role for CDK6 in leukaemic progenitor cell homing.
The article “A robust approach for the generation of functional hematopoietic progenitor cell lines to model leukemic transformation” by Eszter Doma, Isabella Maria Mayer, Tania Brandstoetter, Barbara Maurer, Reinhard Grausenburger, Ingeborg Menzl, Markus Zojer, Andrea Hoelbl-Kovacic, Leif Carlsson, Gerwin Heller, Karoline Kollmann and Veronika Sexl as published in Blood Advances.