Tumors feed on collagen

Collagen, the major component of the extracellular matrix, can be degraded extracellularly by proteases or intracellularly in lysosomes. Mice lacking uPARAP, which mediates the uptake of collagen and thus the intracellular pathway, develop normally. The authors now show that these mice have an advantage over the wild type when it comes to controlling cancer progression.

Stromal cells surrounding breast tumors in the mutant mice did not take in and degrade collagen efficiently. Tumor growth was subsequently restricted in these mice. Proliferation and apoptosis rates of the tumor cells were unchanged, however, so the signals affected...