Fig. 3: The absence of BCL-W does not result in compensatory upregulation of other pro-survival BCL-2 family members in MYC-driven lymphomas.

A Western blots examining and quantifying the expression levels of different BCL-2 family members and other regulators of the intrinsic apoptosis pathway. 12 lymphoma samples from spleens from each of Eµ-Myc^T/+;Bcl-w^+/+ and Eµ-Myc^T/+;Bcl-w^−/− animals were examined, with male (n = 9) and female (n = 15) animals fairly represented (mouse IDs are listed along the bottom of each image (see Supplementary File 1 for complete cohort information)). Apart from BCL-W expression, no obvious, consistent differences in the levels of the indicated proteins were found between lymphomas of the two genotypes. Note that the HSP70 blots shown are representatives from one blot, as the experiment was undertaken over multiple blots, with HSP70 used as the loading control in each instance. Note also that the additional bands seen in the BCL-2 blots are due to these lymphomas being IgM-positive, as determined by flow cytometry; i.e. the bands detected are due to the binding of the HRP-conjugated anti-mouse-Ig secondary antibody to mouse Ig light chain. Complete blots are shown in Supplementary Fig. 1. B Quantification of the protein expression levels revealed that only BCL-W was differentially expressed between lymphomas of the two genotypes (Mann–Whitney test with FDR multiple comparisons, mean rank Eµ-Myc^T/+;Bcl-w^+/+ = 18.5 and Eµ-Myc^T/+;Bcl-w^−/− = 6.5, U = 0.0, n(Eµ-Myc^T/+;Bcl-w^+/+) = n(Eµ-Myc^T/+;Bcl-w^−/−) = 12, p < 0.0001). Data in (B) are presented as mean ± standard deviation. **** = p < 0.0001. While all data are displayed on one graph, comparisons should not be made between different proteins, as apparent differences in expression may be due to variable blot exposure or differences in antibody binding affinities.