A novel lung cancer gene signature mediates metastatic bone colonization by a dual mechanism

Bone is a frequent target of lung cancer metastasis, which is associated with significant morbidity and a dismal prognosis. To identify and functionally characterize genes involved in the mechanisms of osseous metastasis we developed a murine lung cancer model. Comparative transcriptomic analysis identified genes encoding signaling molecules (such as TCF4 and PRKD3), and cell anchorage related proteins (MCAM, and SUSD5), some of which were basally modulated by TGFbeta in tumor cells and in conditions mimicking tumor-stroma interactions. Triple gene combinations induced not only high osteoclastogenic activity but also a marked enhancement of global metalloproteolytic activities in vitro. These effects were strongly associated with robust bone colonization in vivo, whereas this gene subset was ineffective in promoting local tumor growth and cell homing activity to bone. Interestingly, global inhibition of metalloproteolytic activities and simultaneous TGFbeta blockade in vivo led to increased survival and a remarkable attenuation of bone tumor burden and osteolytic metastasis. Thus, this metastatic gene signature mediates bone-matrix degradation by a dual mechanism of induction of TGFbeta-dependent osteoclastogenic bone resorption and enhancement of stroma-dependent metalloproteolytic activities. Our findings suggest the cooperative contribution of host-derived and cell-autonomous effects directed by a small subset of genes in mediating aggressive osseous colonization.

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Vicent S, Luis-Ravelo D, Antón I, García-Tuñón I, Borrás-Cuesta F, Dotor J, De Las Rivas J, Lecanda F