Control of nuclear-cytoplasmic shuttling of Ankrd54 by PKCδ.

Aim: To identify and characterize the effect of phosphorylation on the subcellular localization of Ankrd54.

Methods: HEK293T cells were treated with calyculin A, staurosporin or phorbol 12-myristate 13-acetate (PMA). Cells were transfected with eGFP-tagged Ankrd54 with or without Lyn tyrosine kinase (wild-type, mutant, or mutant).

Heterogeneity in mechanisms of emergent resistance in pediatric T-cell acute lymphoblastic leukemia.

Relapse in pediatric T-cell acute lymphoblastic leukemia (T-ALL) remains a significant clinical problem and is thought to be associated with clonal selection during treatment. In this study we used an established pre-clinical model of induction therapy to increase our understanding of the effect of engraftment and chemotherapy on clonal selection and acquisition of drug resistance in vivo. Immune-deficient mice were engrafted with patient diagnostic specimens and exposed to a repeated combination therapy consisting of vincristine, dexamethasone, L-asparaginase and daunorubicin.

Bioenergetic modulation overcomes glucocorticoid resistance in T-lineage acute lymphoblastic leukaemia.

Drug-resistant forms of acute lymphoblastic leukaemia (ALL) are a leading cause of death from disease in children. Up to 25% of patients with T-cell ALL (T-ALL) develop resistance to chemotherapeutic agents, particularly to glucocorticoids (GCs), a class of drug to which resistance is one of the strongest indicators of poor clinical outcome. Despite their clinical importance, the molecular mechanisms that underpin GC resistance and leukaemia relapse are not well understood.

Drug-gene modeling in pediatric T-cell acute lymphoblastic leukemia highlights importance of 6-mercaptopurine for outcome.

Patients relapsing with T-cell acute lymphoblastic leukemia (T-ALL) face a dismal outcome. The aim of this study was to identify new markers of drug resistance and clinical response in T-ALL. We measured gene expression and drug sensitivity in 15 pediatric T-ALL cell lines to find signatures predictive of resistance to 10 agents used in therapy.

Influence of wild-type MLL on glucocorticoid sensitivity and response to DNA-damage in pediatric acute lymphoblastic leukemia.

Background: Rearrangement of the mixed-lineage leukemia gene (MLL) is found in 80% of infant acute lymphoblastic leukemia (ALL) and is associated with poor prognosis and resistance to glucocorticoids (GCs). We have recently observed that GC resistance in T-ALL cell lines is associated with a proliferative metabolism and reduced expression of MLL. In this study we have further explored the relationship between MLL status and GC sensitivity.

Validation of a mouse xenograft model system for gene expression analysis of human acute lymphoblastic leukaemia.

Background: Pre-clinical models that effectively recapitulate human disease are critical for expanding our knowledge of cancer biology and drug resistance mechanisms. For haematological malignancies, the non-obese diabetic/severe combined immunodeficient (NOD/SCID) mouse is one of the most successful models to study paediatric acute lymphoblastic leukaemia (ALL). However, for this model to be effective for studying engraftment and therapy responses at the whole genome level, careful molecular characterisation is essential.

Liar, a novel Lyn-binding nuclear/cytoplasmic shuttling protein that influences erythropoietin-induced differentiation.

Erythropoiesis is primarily controlled by erythropoietin (Epo), which stimulates proliferation, differentiation, and survival of erythroid precursors. We have previously shown that the tyrosine kinase Lyn is critical for transducing differentiation signals emanating from the activated Epo receptor. A yeast 2-hybrid screen for downstream effectors of Lyn identified a novel protein, Liar (Lyn-interacting ankyrin repeat), which forms a multiprotein complex with Lyn and HS1 in erythroid cells.