Genomic analysis reveals molecular characterization of CD30+ and CD30− extranodal natural killer/T-cell lymphomas (ENKTLs)

Abstract

Extranodal natural killer (NK)/T-cell lymphoma (ENKTL) is prevalent in the Asian population; however, little is known about its molecular characteristics. In this study, we examined the CD30 expression in ENKTLs and then performed whole exome sequencing on ten CD30+ ENKTL and CD30− ENKTL paired samples. CD30 was positive in 55.74% of the ENKTLs. Single nucleotide and insertion/deletion polymorphism analyses revealed that 53.41% of the somatic mutations in CD30+ ENKTLs were shared with CD30− ENKTLs, including mutations in SERPINA9, MEGF6, MUC6, and KDM5A. Frequently mutated genes were primarily associated with cell proliferation and migration, the tumor microenvironment, energy and metabolism, epigenetic modulators, vascular remodeling, and neurological function. PI3K-AKT, cAMP, cGMP-PKG, and AMPK pathways were enriched in both CD30+ and CD30− ENKTLs. Copy number variation analysis identified a unique set of genes in CD30+ ENKTLs, including T-cell receptor genes (TRBV6-1 and TRBV8), cell cycle-related genes (MYC and CCND3), immune-related genes (GPS2, IFNA14, TTC38, and CTSV), and a large number of ubiquitination-related genes (USP32, TRIM23, TRIM2, DUSP7, and UBE2QL1). BCL10 mutation was identified in 6/10 CD30+ ENKTLs and 7/10 CD30− ENKTLs. Immunohistochemical analysis revealed that the expression pattern of BCL10 in normal lymphoid tissues was similar to that of BCL2; however, its expression in ENKTL cells was significantly higher (67.92% vs. 16.98%), implying the potential application of BCL10 inhibitors for treating ENKTLs. These results provide new insights into the genetic characteristics of CD30+ and CD30− ENKTLs, and could facilitate the clinical development of novel therapies for ENKTL.