Antibody-Mediated Targeting of Secretory Protein SCUBE3 Suppresses Cancer Progression by Inhibiting Oncogenic Signaling and Inducing Anti-tumor Immunity

Through a loss-of-function genomic screening approach, we identified Signal peptide CUB domain EGF-like 3 (SCUBE3) as a critical player for the survival and therapy resistance of cancer cells, particularly in triple negative breast cancer (TNBC). To further understand the mechanism by which SCUBE3 may support tumor growth and metastasis, we performed gene expression analysis on MDA-MB-231 cells stably silenced for SCUBE3. Pathway analysis reveled that Myc signaling, G2M checkpoint and DNA repair-associated genes were highly downregulated, while IFN gamma, inflammatory response and immunity-associated pathways were highly upregulated in SCUBE3-silenced TNBC cells. Overall design: MDA-MB-231 cells were transfected with lentivirus containing human shRNA (or scrambled shRNA) plasmids for SCUBE3. Transfected cells were then selected with Puromycin for a week and checked for expression of SCUBE3 by western blots. Three replicates for each group were used for RNA-seq library construction and sequenced with Illumina HiSeq 3000 system.