Carcinoma cells may modulate their supporting connective tissue.

The patterns of growth of two chemically-induced murine squamous cell carcinoma cell lines and their effect on a deep connective tissue graft bed were examined in syngeneic C57Bl/6 mice. The two cell lines displayed markedly different patterns of histo-differentiation but in vivo the poorly-differentiated line (FS) gave rise to tumours with much lower inocula than the well-differentiated cell line (A5). To evaluate the effect of the tumour cells on the graft bed a bioassay involving transplantation of epidermal sheets was used. Whereas the pretreatment of the deep connective tissue graft bed with the FS cell line facilitated the subsequent growth of the epidermal sheets, beds treated with the A5 cell line, lethally irradiated tumour cells or receiving no treatment failed to support continued growth of normal epidermis. We suggest that this ability of a carcinoma cell line to modify the connective tissue may facilitate the establishment of metastatic deposits.