The genetic landscape of mutations in Burkitt lymphoma

Burkitt lymphoma is characterized by deregulation of MYC, but the contribution of other genetic mutations to the disease is largely unknown. Here, we describe the first completely sequenced genome from a Burkitt lymphoma tumor and germline DNA from the same affected individual. We further sequenced the exomes of 59 Burkitt lymphoma tumors and compared them to sequenced exomes from 94 diffuse large B-cell lymphoma (DLBCL) tumors. We identified 70 genes that were recurrently mutated in Burkitt lymphomas, including ID3, GNA13, RET, PIK3R1 and the SWI/SNF genes ARID1A and SMARCA4. Our data implicate a number of genes in cancer for the first time, including CCT6B, SALL3, FTCD and PC. ID3 mutations occurred in 34% of Burkitt lymphomas and not in DLBCLs. We show experimentally that ID3 mutations promote cell cycle progression and proliferation. Our work thus elucidates commonly occurring gene-coding mutations in Burkitt lymphoma and implicates ID3 as a new tumor suppressor gene. Gene expression profiling on 21 Burkitt lymphomas was performed using standard Affymetrix protocols as described previously. Briefly, 1 μg of total RNA was reverse transcribed, using oligo(dT) primer to synthesize cDNA. T7 primer was used for in vitro transcription, resulting in labeled cRNA, which was fragmented and hybridized to Affymetrix Whole-Genome Gene 1.0 ST microarrays. Microarrays were washed and scanned, and the data were normalized as described previously.