The inhibitor of differentiation-1 (Id1) enables lung cancer liver colonization through activation of an EMT program in tumor cells and establishment of the pre-metastatic niche

Abstract: Id1 promotes carcinogenesis and metastasis, and predicts prognosis of non-small cell lung cancer (NSCLC)-adenocarcionoma patients. We hypothesized that Id1 may play a critical role in lung cancer colonization of the liver by affecting both tumor cells and the microenvironment. Depleted levels of Id1 in LLC (Lewis lung carcinoma cells, LLC shId1) significantly reduced cell proliferation and migration in vitro. Genetic loss of Id1 in the host tissue (Id1(-/-) mice) impaired liver colonization and increased survival of Id1 animals. Histologically, the presence of Idl in tumor cells of liver metastasis was responsible for liver colonization. Microarray analysis comparing liver tumor n…