Modulation of tumorigenesis by the pro-inflammatory microRNA miR-301a in mouse models of lung cancer and colorectal cancer

Lung cancer and colorectal cancer account for over one-third of all cancer deaths in the United States. MicroRNA-301a (miR-301a) is an activator of both nuclear factor-κB (NF-κB) and Stat3, and is overexpressed in both deadly malignancies. In this work, we show that genetic ablation of miR-301a reduces Kras-driven lung tumorigenesis in mice. And miR-301a deficiency protects animals from dextran sodium sulfate-induced colon inflammation and colitis-associated colon carcinogenesis. We also demonstrate that miR-301a deletion in bone marrow-derived cells attenuates tumor growth in the colon carcinogenesis model. Our findings ascertain that one microRNA—miR-301a—activates two major inflammatory pathways (NF-κB and Stat3) in vivo, generating a pro-inflammatory microenvironment that facilitates tumorigenesis.