A role of DDR2 and substrate stiffness on cancer cell transcriptome and proliferation

Extracellular matrix (ECM) regulates carcinogenesis. As a major ECM component, collagen interacts with integrin and a non-typical receptor discoidin domain receptor tyrosine kinase 2 (DDR2), but how DDR2 regulates cancer progression is poorly understood. Apart from its signaling function, ECM provides a mechanical environment for cancer, but the impact of biomechanics on cancer remains enigmatic. Here, we performed RNA-seq of a human neuroblastoma cell line SH-SY5Y. We found that DDR2 knockdown, but not increasing substrate stiffness, upregulated pro-proliferative genes and down-regulated axonogenesis genes. Surprisingly, despite no transcriptome changes, increasing of stiffness attenuates SH-SY5Y cell proliferation, an effect also observed after DDR2 knockdown. Our results indicate that two ECM effectors, DDR2 and biomechanics, could control cancer cell proliferation through different mechanisms.