Integrative genomic analysis identifies key pathogenic mechanisms in primary mediastinal large B-cell lymphoma

Primary mediastinal large B-cell lymphoma (PMBL) represents a clinically and pathologically distinct subtype of large B-cell lymphomas. Furthermore, molecular studies, including global gene expression profiling, have provided evidence that PMBL is more closely related to classical Hodgkin lymphoma (cHL). Although targeted sequencing studies have revealed a number of mutations involved in PMBL pathogenesis, a comprehensive description of disease-associated genetic alterations and perturbed pathways is still lacking. Here, we performed whole-exome sequencing of 95 PMBL tumors to inform on oncogenic driver genes and recurrent copy number alterations. The integration of somatic gene mutations with gene expression signatures provides further insights into genotype–phenotype interrelation in PMBL. We identified highly recurrent oncogenic mutations in the Janus kinase-signal transducer and activator of transcription and nuclear factor B pathways, and provide additional evidence of the importance of immune evasion in PMBL (CIITA, CD58, B2M, CD274, and PDCD1LG2). Our analyses highlight the interferon response factor (IRF) pathway as a putative novel hallmark with frequent alterations in multiple pathway members (IRF2BP2, IRF4, and IRF8). In addition, our integrative analysis illustrates the importance of JAK1, RELB, and EP300 mutations driving oncogenic signaling. The identified driver genes were significantly more frequently mutated in PMBL compared with diffuse large B-cell ly...

Source: Blood - September 4, 2019 Category: Hematology Authors: Mottok, A., Hung, S. S., Chavez, E. A., Woolcock, B., Telenius, A., Chong, L. C., Meissner, B., Nakamura, H., Rushton, C., Vigano, E., Sarkozy, C., Gascoyne, R. D., Connors, J. M., Ben-Neriah, S., Mungall, A., Marra, M. A., Siebert, R., Scott, D. W., Sava Tags: Lymphoid Neoplasia Source Type: research