An experimental model for studying the desmoplastic response to tumor invasion

BL6 melanoma cells injected subcutaneously in 18-month-old syngeneic C57BL/6 mice elicit a marked fibrotic response highly similar in myofibroblast composition and Type V collagen content to that characterizing the desmoplastic response of human carcinomas. This host response can be quantitated in vivo by measuring both hydroxyproline content (total collagen) and incorporation of intraperitoneally injected [14C] proline into collagenase-sensitive protein (new collagen synthesis). 70% inhibition of the response can be achieved with daily L-3,4-dehydroproline. The response can be similarly quantitated in vitro in explants of desmoplastic tumor tissue. The model allows for subsequent investigations of the effects of the desmoplastic response on tumor invasion and metastasis.