American Society of Hematology

Figure 1.

Recurrent splice site mutations in DLBCL. (A) Genes recurrently mutated at splice sites according to our reanalysis of the dataset of Reddy et al1 (N = 1001). We only considered mutations that were confirmed as somatic by Schmitz et al2 or Chapuy et al.3 The genes shown in the figure were mutated in at least 5 patients. For each gene, the frequency of splice site mutant patients is shown in the vertical axis. The heatmap below shows the presence (green) or absence (gray) of relevant features for each gene. Aberrant RNA evidence, at least 1 splice site mutant patient had an RNA aberration that could be attributed to the mutation according to our analyses; Cancer Gene Census, the gene is part of the Cancer Gene Census; GCB-/ABC muts., the gene is preferentially mutated in the GCB or ABC subtype according to Reddy et al1 or Schmitz et al.2 (B) Ratio between the frequency of splice site mutations per nucleotide and the frequency of coding mutations per nucleotide for the 22 recurrent splice site mutant genes that had nonzero coding mutation frequency in the dataset of Reddy et al.1 (C) Mutant CD79BIR increases surface immunoglobulin M (IgM) at a higher extent than CD79BY196H. The ABC DLBCL line U-2932 was transduced with CD79BWT, mutant CD79BY196H, or mutant CD79BIR. Surface IgM is depicted gating on a cotransduced green fluorescent protein (GFP) marker to identify the subset of transduced cells with equivalent ectopic CD79B RNA expression. (D) Surface IgM expression in U-2932 cells transduced with the indicated CD79B isoforms. U-2932 GFP-positive transduced cells are compared with untransduced cells. (E) Western blot of CD79B, phosphorylated RELA/p65 (Ser536), and phosphorylated Akt (Ser473) in U-2932 cells after overexpression of mutant or wild-type CD79B. The numbers indicate the fold change between each CD79B overexpression model and the parental cell line, previously normalized with glyceraldehyde-3-phosphate dehydrogenase (GAPDH), according to a densitometry analysis using ImageJ. *The epitope recognized by the anti-CD79B antibody is within the region that is lost by CD79BIR, which is why overexpression cannot be detected by this method. However, we confirmed CD79BIR plasmid overexpression by flow cytometry (GFP+ signal).

Recurrent splice site mutations in DLBCL. (A) Genes recurrently mutated at splice sites according to our reanalysis of the dataset of Reddy et al¹ (N = 1001). We only considered mutations that were confirmed as somatic by Schmitz et al² or Chapuy et al.³ The genes shown in the figure were mutated in at least 5 patients. For each gene, the frequency of splice site mutant patients is shown in the vertical axis. The heatmap below shows the presence (green) or absence (gray) of relevant features for each gene. Aberrant RNA evidence, at least 1 splice site mutant patient had an RNA aberration that could be attributed to the mutation according to our analyses; Cancer Gene Census, the gene is part of the Cancer Gene Census; GCB-/ABC muts., the gene is preferentially mutated in the GCB or ABC subtype according to Reddy et al¹ or Schmitz et al.² (B) Ratio between the frequency of splice site mutations per nucleotide and the frequency of coding mutations per nucleotide for the 22 recurrent splice site mutant genes that had nonzero coding mutation frequency in the dataset of Reddy et al.¹ (C) Mutant CD79B^IR increases surface immunoglobulin M (IgM) at a higher extent than CD79B^Y196H. The ABC DLBCL line U-2932 was transduced with CD79B^WT, mutant CD79B^Y196H, or mutant CD79B^IR. Surface IgM is depicted gating on a cotransduced green fluorescent protein (GFP) marker to identify the subset of transduced cells with equivalent ectopic CD79B RNA expression. (D) Surface IgM expression in U-2932 cells transduced with the indicated CD79B isoforms. U-2932 GFP-positive transduced cells are compared with untransduced cells. (E) Western blot of CD79B, phosphorylated RELA/p65 (Ser536), and phosphorylated Akt (Ser473) in U-2932 cells after overexpression of mutant or wild-type CD79B. The numbers indicate the fold change between each CD79B overexpression model and the parental cell line, previously normalized with glyceraldehyde-3-phosphate dehydrogenase (GAPDH), according to a densitometry analysis using ImageJ. *The epitope recognized by the anti-CD79B antibody is within the region that is lost by CD79B^IR, which is why overexpression cannot be detected by this method. However, we confirmed CD79B^IR plasmid overexpression by flow cytometry (GFP+ signal).

This Feature Is Available To Subscribers Only