Targeting a Galectin-3/EGR1 transcriptional complex inhibits the pro-metastatic signature in TRIM49-deficient gastric adenocarcinoma II

Distal metastasis, driven by intracellular signaling rewiring, is a leading cause of cancer mortality. The role of post-translational modifications in metastasis remains unclear. A CRISPR screen in a gastric adenocarcinoma (GAC) mouse model identified TRIM49 as a metastasis suppressor. TRIM49 is downregulated in most advanced GACs, correlating with poor prognosis. Galectin-3, stabilized in TRIM49-deficient cells due to impaired degradation, forms a complex with EGR1, enhancing pro-metastatic gene expression. Disrupting this complex with GB1107 inhibits metastasis in mouse models. The Galectin-3/EGR1 complex in TRIM49-deficient GAC is a key driver of metastasis and a potential therapeutic target. Overall design: The in vivo CRISPR-Cas9 screen experiment with whole genome CRISPR knockout pooled library (hGeCKOv2.0) was performed by Shanghai Genechem Co.,Ltd. Firstly, the GC cells infected with pooled hGeCKOv2.0 lentivirus library at a multiplicity of infection of 0.3 to ensure most cells received only one stably integrated RNA guide. Then, the infected GC cells were orthotopically injected to stomach. Further, the in situ and metastatic focuses were harvested. To guarantee optimal utilization of data, each specimen was divided into two sub-libraries, and genomic DNA was isolated for the amplification of sgRNAs, which were then sequenced on an Illumina HiSeq X instrument.