Project name: The proto-oncogene TCL1A deregulates mitotic checkpoint transition and genomic stability in CLL

Description: Upregulation of the proto-oncogene TCL1A is causally implicated in various B- and T-cell malignancies. High-level TCL1A correlates with aggressive disease features and inferior clinical outcomes. However, molecular and cell-biological consequences of TCL1A dysregulation are not fully elucidated.To analyze if TCL1A’s oncogenic activity depends on its subcellular localization, we transduced murine hematopoietic stem cells and progenitor cells (HSC/HPC) with three different human TCL1A variants, being wild type, membrane-localized myristoylated (myr) TCL1A, and TCL1A fused to a nuclear localization signal (nls). All three groups developed mostly B-cell leukemias/lymphomas and less frequently CD4/CD8 double-positive or double-negative T-cell leukemia/lymphomas. Mice transplanted with cells expressing nls-hTCL1A had a significantly shorter survival in comparison to mice harboring wt TCL1A. Gene set enrichment analysis of gene expression profiling data from B-cell tumors identified nuclear pathways including DNA repair, cell cycle, and mitotic spindle to be enriched in the nls-hTCL1A over the hTCL1A cohort.Overall design: Primary hematopoietic stem cells (HSC)/hematopoietic progenitor cells (HPC) were isolated from tibias and femurs of B6-SJL mice carrying the differential Ptprca pan leukocyte marker CD45.1. Cells were depleted of lineage-committed cells using a Lineage Cell Depletion Kit (Miltenyi Biotec, Bergisch Gladbach, Germany). Cells were retrovirally transduced in vitro with MP91-EGFP, -hTCL1A, -myr-hTCL1A, or -nls-hTCL1A. C57BL/6 recipient mice were irradiated with a split dose of 5.5Gy each, with 24 hours between doses, using a BIOBEAM 2000 Cs-137 chloride gamma irradiator (Eckert & Ziegler, Berlin, Germany). One hour after the last dose, 1x10^6 transduced cells were transplanted into each recipient mouse. The development of leukemias was monitored by flow cytometry analysis of blood samples. Gene expression profiles (GEP) were performed on B-cell tumor samples (>70% tumor cell content) from spleens of hTCL1A (n=3), myr-hTCL1A (n=3), and nls-hTCL1A recipient mice (n=3) and EGFP control mice (CD19+GFP+ cells at day 100, n=3). Analyses were performed on an Affymetrix Mouse Gene 1.0 ST Array.

Data type: Transcriptome or Gene expression

Sample scope: Multiisolate

Relevance: ModelOrganism

Last updated: 2021-12-21