Gene expression profiling of metastatic lung cancer cell lines

During malignant disease progression, the extracellular matrix (ECM) of epithelial tumors accumulates inter-molecular cross-links between collagen strands; these cross-links enhance ECM stiffness and trigger tumor cell invasion and dissemination, but the mechanisms that regulate intra-tumoral collagen maturation have not been fully defined. Using a new mouse model of metastatic lung adenocarcinoma driven by mutant K-ras expression and Cdkn1a inactivation, we showed that tumor cell invasion and metastasis are driven by high expression of lysyl hydroxylase 2 (LH2), an enzyme that hydroxylates telomeric lysine (Lys) residues on collagen. We interbred KrasLA1 mice, which develop non-metastatic lung adenocarcinomas at 8-10 months of age because of the expression of a somatically activated K-rasG12D allele, with Cdkn1a-/- mice, which develop sarcomas and B cell lymphomas because of depletion of p21. Cohorts were generated that had neither, either, or both mutant alleles. KrasLA1 mice that were p21-deficient (KC mice) had a shorter mean time to death than did p21-replete ones. We established cell lines from the tumors, and compared cell lines from highly metastatic tumors with those from poorly metastatic tumors.