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Biomedical subjects

Cheryl L Willman

Publications and source records attributed to Cheryl L Willman.

3 recordsLinked to original sources

Prognostic impact of age and MDS-associated mutations in NPM1-mutated AML.

Nucleophosmin-1 (NPM1) mutations define a major molecular subtype of acute myeloid leukemia (AML) and is generally associated with favorable prognosis. However, the impact of myelodysplastic syndrome-associated mutations (MDSm+) on patient outcomes within this subgroup remains uncertain. We retrospectively analyzed 271 patients with NPM1-mutated AML from 3 independent cohorts (SWOG, Fred Hutch, and Beat AML) to assess the prognostic significance of MDSm+ and its interaction with age. MDSm+ occurred in 17% of patients, most commonly involving SRSF2 and SF3B1. Although MDSm+ was associated with inferior overall survival (OS) compared with MDSm- in European LeukemiaNet (ELN) 2022 favorable-risk patients (hazard ratio [HR], 2.0; P = .008), this effect was largely driven by worse outcomes in older patients (≥65 years) as older ELN2022 favorable-risk patients had poor OS regardless of the presence of MDSm+ compared with younger patients. After stratification of patients by age, there was not a significant difference between MDSm+ and MDSm- in either younger patients (HR, 0.99; P = .98) or older patients (HR, 1.42; P = .33). These findings indicate that MDSm+ in NPM1 + AML is not independently associated with adverse risk after adjusting for age, and highlight the need for age-adjusted AML risk models.

Journal Article

Signalling thresholds and negative B-cell selection in acute lymphoblastic leukaemia.

B cells are selected for an intermediate level of B-cell antigen receptor (BCR) signalling strength: attenuation below minimum (for example, non-functional BCR) or hyperactivation above maximum (for example, self-reactive BCR) thresholds of signalling strength causes negative selection. In ∼25% of cases, acute lymphoblastic leukaemia (ALL) cells carry the oncogenic BCR-ABL1 tyrosine kinase (Philadelphia chromosome positive), which mimics constitutively active pre-BCR signalling. Current therapeutic approaches are largely focused on the development of more potent tyrosine kinase inhibitors to suppress oncogenic signalling below a minimum threshold for survival. We tested the hypothesis that targeted hyperactivation--above a maximum threshold--will engage a deletional checkpoint for removal of self-reactive B cells and selectively kill ALL cells. Here we find, by testing various components of proximal pre-BCR signalling in mouse BCR-ABL1 cells, that an incremental increase of Syk tyrosine kinase activity was required and sufficient to induce cell death. Hyperactive Syk was functionally equivalent to acute activation of a self-reactive BCR on ALL cells. Despite oncogenic transformation, this basic mechanism of negative selection was still functional in ALL cells. Unlike normal pre-B cells, patient-derived ALL cells express the inhibitory receptors PECAM1, CD300A and LAIR1 at high levels. Genetic studies revealed that Pecam1, Cd300a and Lair1 are critical to calibrate oncogenic signalling strength through recruitment of the inhibitory phosphatases Ptpn6 (ref. 7) and Inpp5d (ref. 8). Using a novel small-molecule inhibitor of INPP5D (also known as SHIP1), we demonstrated that pharmacological hyperactivation of SYK and engagement of negative B-cell selection represents a promising new strategy to overcome drug resistance in human ALL.

Amino Acid Motifs