KRas targeting by clinically significant miR-193a-3p inhibits mutant KRas lung cancer growth, circulating tumor cells and metastasis in vivo

Ras family oncogenes are mutated in approximately 30% of human cancers and cause resistance to multiple treatment modalities. While identifying methods to directly target mutant KRas have been challenging, targeting regulators of KRas may be beneficial. Using a systems approach of integrating a genome-wide miRNA screen with patient data of a phospho-proteomic signature of the KRas downstream pathway, we identified miR-193a-3p as a potent tumor suppressor capable of reversing KRas-related signaling, whereby the 3’UTR of KRas is directly targeted via two miR-193a-3p binding sites. Mechanistic studies revealed that miR-193a-3p inhibited the KRas protein signature, KRas downstream transcriptomic network, proliferation, induced a G1 arrest, and reduced colony formation in 3D cultures through direct targeting of KRas. An ex vivo lung cancer model showed that miR-193a-3p significantly reduced the viability of circulating tumor cells as well as decreased metastasis. In vivo studies revealed that miR-193a-3p significantly reduced tumor growth as well as metastasis of a KRas-mutant lung cancer xenograft model. Total RNA extracted 48 hours after transfection with either control (NT) or miR-193a-3p, with 3 replicates per condition