Fig. 8: Disrupting condensation of TFE3 fusions inhibits tRCC growth.

a Schematic depicting the strategy to employ MBP linked nanobody against GFP (LaG-MBP) to dissolve the condensates of TFE3 oncofusions. b The design of a chemically switchable split nanobody (CB) system. The GFP nanobody (LaG) is split to an N-terminus linked with cpFRB and a C-terminus linked with FKBP and MBP. Rapamycin (Rapa) promotes the interaction of cpFRB and FKBP to form functionally intact LaG-MBP and disrupt the condensation of GFP-labeled NONO-TFE3. Created in BioRender. Suris, A. (https://BioRender.com/jvewyzg). c Representative images (left) and quantification (right) of droplet formation for UOK109 KI cells transfected with the indicated constructs with or without rapamycin (Rapa) treatment. (n = 3 independent biological replicates; one-way ANOVA with Tukey’s post-hoc test). Scale bar, 10 µm. Data are shown as mean ± SD. d Representative images (left) and quantification (right) of clone formation assay results for UOK109 KI cells transduced with the indicated constructs with or without rapamycin (Rapa) treatment. (n = 3 independent biological replicates; one-way ANOVA with Tukey’s post-hoc test). Data are shown as mean ± SD.  e Experimental setup for monitoring tumor growth in vivo. f Representative images of isolated tumor masses (left) and quantification (right) of tumor weights at day 24 for the in vivo experiment shown in e. (n = 10 mice; one-way ANOVA with Tukey’s post-hoc test). Data are shown as mean ± SD. g, h Principal component analysis (g) and heatmap (h) of RNA-seq data from UOK109 KI cells treated with dTAG-13 or rapamycin (Rapa). n = 2 independent biological replicates. e Venn diagram showing the overlap of differentially expressed genes (DEGs) identified from RNA-seq analysis of UOK109 KI cells treated with dTAG-13 or rapamycin (Rapa) for 4 h. Source data are provided as a Source Data file.