Functional evaluation of alternative splicing in the FAM190A gene.

The human FAM190A gene undergoes frequent alteration in human cancer, most commonly involving in-frame deletions in exon 9 or exons 9 & 10. These deletions form novel peptide sequences, serving as presumptive cancer-specific neo antigens. However, it remains elusive whether these in-frame deletions of FAM190A could induce oncogenic properties in vivo. In this study, we aimed to explore the functional significance of in-frame deletions in FAM190A genes. We generated two deletion mutant forms, FAM190AΔexon9 and FAM190AΔexon9&10, and examined their gain-of-function effects in vitro and in vivo. Global transcript profiling in NIH3T3 cells revealed that the transcripts displaying altered expression following introduction of FAM190AΔexon9 and FAM190AΔexon9&10 were significantly enriched for genes assigned to cellular movement and cell-to-cell signaling, respectively. Furthermore, ectopic expression of FAM190AΔexon9 and FAM190AΔexon9&10 induced in vivo tumor formation in nu/nu mice. Taken together, our results are the first to demonstrate the in vivo oncogenic properties of in-frame deletions in the FAM190A gene and indicate that these transcript variants might be clinically applicable as therapeutic targets in patients with cancer.