Position statement of the Royal Spanish Football Federation for the resumption of football activities after the COVID-19 pandemic (June 2020)
Helena Herrero-Gonzalez, Rafael Martín Acero, Juan Del Coso, Carlos Lalín-Novoa, Rafel Pol, Pilar Martín-Escudero, Ana Isabel De la Torre, Christopher G. Hughes, Magni Mohr, Francisco Biosca, Rafael Ramos
Abstract
<h3>Abstract</h3> IKAROS family zinc finger 1 (<i>IKZF1</i>) alterations represent a diverse group of genetic lesions that are associated with an increased risk of relapse in B-lymphoblastic leukemia (B-ALL). Due to the heterogeneity of concomitant lesions it remains unclear how <i>IKZF1</i> abnormalities directly affect cell function and therapy resistance and whether their consideration as a prognostic indicator is valuable in improving outcome. We used CRISPR/Cas9 to engineer multiple panels of isogeneic lymphoid leukemia cell lines with a spectrum of <i>IKZF1</i> lesions in order to measure changes in chemosensitivity, gene expression, cell cycle, and in vivo engraftment dynamics that can be directly linked to loss of IKAROS protein. <i>IKZF1</i> knockout and heterozygous null cells displayed relative resistance to a number of commonly employed therapies for B-ALL including dexamethasone, vincristine, asparaginase, and daunorubicin. Transcription profiling revealed a stem/myeloid cell-like phenotype and JAK/STAT upregulation after IKAROS loss. We also used a CRISPR homology-directed repair (HDR) strategy to knock-in the dominant-negative IK6 isoform tagged with GFP into the endogenous locus and observed a similar drug resistance profile with the exception of retained sensitivity to dexamethasone. Interestingly, <i>IKZF1</i> knockout and IK6 knock-in cells both have significantly increased sensitivity to cytarabine, suggesting intensification of nucleoside analog therapy may be specifically effective for <i>IKZF1</i>-deleted B-ALL. Both types of <i>IKZF1</i> lesions decreased survival time of xenograft mice, with higher numbers of circulating blasts and increased organ infiltration. Given these findings, exact specification of <i>IKZF1</i> status in patients may be a beneficial addition to risk stratification and could inform therapy. <h3>Key points</h3> Engineered <i>IKZF1</i> perturbations result in a stem-cell like expression signature, enhanced engraftment in vivo, and multi-drug resistance Loss of IKAROS may result in new vulnerabilities due to increased sensitivity to cytarabine and upregulation of JAK/STAT and mAb targets