Collagen I promotes cancer cell survival via amino acid import and mTORC1/S6 activation

Invasive breast and pancreatic cancer cells thrive within a collagen I-rich, poorly perfused extracellular matrix (ECM) network, necessitating robust metabolic adaptation to endure nutrient deficiency, such as glucose starvation. Here we demonstrate that collagen I is critical for the survival and growth of breast and pancreatic cancer cells. Mechanistically, collagen I promotes α2 β1 integrin-dependent S6 phosphorylation by the mammalian target of rapamycin complex 1 (mTORC1) and drives the membrane localisation of the (LAT1)-4F2hc amino acid transporter. This process ensures a sustained intracellular essential amino acid supply, further fuelling mTORC1 signalling and limiting autophagy. This collagen I-driven pathway is essential for cancer cell survival, as inhibiting the activity of α2 β1 integrin or the LAT1-4F2hc transporter significantly reduces cell growth and invasion in both 2D and 3D models. Finally, the clinical relevance of these transporters is underscored by the significant upregulation of LAT1-4F2hc expression in basal-like breast and pancreatic cancer patients, correlating with poor prognosis and drug resistance. Collectively, our findings highlight that targeting the LAT1-4F2hc transporter might represent a highly promising therapeutic strategy to limit cancer cell growth and invasion in highly fibrotic and nutrient-deprived tumours.