Page 120 - Haematologica-5

R. Bomben et al.
group-2 category (Online Supplementary Table S4). Similar results were obtained by GSEA which highlighted a con- stitutive overexpression of genes related to the BCR sig- naling pathways in the context of group-2 patients (Figure 2A and Online Supplementary Table S5). Therefore, here- after the two PCA groups were identified as BCRlow (group-1) and BCRhigh (group-2).
A 6-gene signature identifies BCRlow and BCRhigh MCL samples
Having identified two different groups of MCL patients at diagnosis with a different expression of genes related to the BCR pathway, we overlapped the genes included in the gene sets related to the BCR pathway (115 probes) and the differentially expressed genes (922 probes) to cre-
AB
D
E
C
852
Figure 2. 6-gene signature and Decision Tree (DT) prediction model. (A) Gene Expression Profile data of BCRlow and BCRhigh MCL samples were tested using Gene set enrichment analysis (GSEA). Reported are the significant gene sets differentially expressed and related to the B-Cell Receptor (BCR) pathway. (B) Venn diagram derived by merging the differentially expressed probes and the genes belonging to the BCR related gene sets. In bold genes selected as the 6-gene signature. (C) Hierarchical clustering of 14 BCRlow cases and 13 BCRhigh cases, using the six gene values. Color codes for gene expression values refer to mean centered log-ratio values. (D) Hierarchical clustering of 8 BCRlow cases and 9 BCRhigh cases belonging to the training set of DT prediction model, using the six gene qRT-PCR values. (E) Hierarchical clustering of 6 BCRlow cases and 4 BCRhigh cases belonging to the validation set of DT prediction model, using the six gene qRT-PCR values. Bar under the heat-map refers to prediction generated by the DT prediction model. Color codes for gene expression values refer to mean centered log-ratio values.
haematologica | 2018; 103(5)