Figure 6. The synthetic lethal interaction between EJC and eIF4E is essential for cancer cell migration.
. (A) Representation of GO terms enriched in synthetic lethal partners of eIF4E in a cellular context. Each circle represents a gene, and the size of the circle corresponds to the −log10(p value) from a paired Wilcoxon test to show the significance of the mean difference of the phenotype between eIF4E+/− and eIF4E+/+ MEFs in the screen.
(B) Cartoon of the exon-junction complex.
(C) Schematic representation of the RNA-seq experiment.
(D) Heatmap representation of differentially expressed genes in comparison to eIF4E or Rbm8a depletion. Although the alterations were minor when Rbm8a or eIF4E was depleted (left and middle columns, respectively), more significant changes were observed when Rbm8a was depleted in eIF4E+/− MEFs (right column). Each line represents the value calculated based on log2(FC) × −log10(p value).
(E) Enriched GO terms of differentially expressed genes in eIF4E+/− Rbm8a KD versus eIF4E+/− Scramble MEFs (right column of Figure 4D). The size of the dots represents the number of genes in each category.
(F) qPCR analysis of mRNA targets (Itga5, Mmp2, Snail1) that are specifically downregulated in eIF4E+/− Rbm8a KD. Multiple t tests were performed to determine statistical significance (n > 3).
(G) Schematic representation of transwell migration assay and a representative confocal image of migrated cells. Migrated cells were counted for each group (n > 30). The bottom right graph represents the normalized value of Rbm8a KD over the scramble control in eIF4E+/+ and eIF4E+/− MEFs. Multiple t tests were performed to determine statistical significance.
(H) Progression-free survival probability in liver cancer using TCGA data. The p value represents the interaction score between eIF4E and Rbm8a expression. A two-way ANOVA test was performed to determine statistical significance.
All values represent the mean + SEM. *p < 0.01, **p < 0.001, ***p < 0.0001. See also Figure S4.