Collagen synthesis by cloned mouse mammary tumor cells
Roesel, R.A.; Cutroneo, K.R.; Scott, D.F.; Howard, E.F.
Cancer Research 38(10): 3269-3275
1978
ISSN/ISBN: 0008-5472 PMID: 210933 Document Number: 126022
Neoplasms require stroma to support their growth. Collagen is the major protein of stroma, and its biosynthesis is an important event in the development and growth of tumors. Collagen synthesis is considered to be a property of fibroblasts. The cell type responsible for collagenous stroma formation in neoplastic tissue was not fully identified. In an attempt to answer this question, the collagenous synthetic activity of 3 cloned cell lines that were derived from mouse mammary carcinomas was compared with that of cultured mouse fibroblasts. Cells were analyzed for activity of prolyl hydroxylase, the enzyme responsible for the formation of hydroxyproline in collagen. The cells were also incubated with L[U-14C]proline in the presence of 2 .times. 10-4 M sodium ascorbate, and the amount of collagenase-digestible protein was determined. The rate of hydroxyproline formation was also determined. All 3 parameters of collagen synthetic activity indicated that the mammary tumor cell lines synthesize collagen. The amount of collagen synthesized relative to noncollagen protein was lower than in the fibroblast cultures. Cells from solid tumors derived after s.c. injection of the tumorigenic cell lines into isogeneic mice were obtained, and prolyl hydroxylase activity and collagenase-digestible protein were determined. The results indicated that the primary cells derived from the solid tumors synthesized approximately the same amount of collagen relative to noncollagen protein as their respective cell lines growing in culture. The primary cells also had a similar level of prolyl hydroxylase activity, as the cultured cells.