Skeletal muscle-derived fibroblast-like cells fail to enable HeLa cells to induce bone in the murine kidney

HeLa cells fail to induce bone in murine kidneys, despite being highly chondro/osteogenic when implanted into thigh muscles. Bone induction in the kidneys failed also when HeLa cells were grafted together with skeletal-muscle-derived cell cultures. It is postulated that kidney parenchyma releases unidentified factcor(s) which prevent activation by inducer of cells termed Friedenstein's (1976) "inducible osteoprogenitor cells", while this hypothetical factor does not prevent further differentiation of"determined osteoprogenitor cells", thus allowing bone to form in the renal parenchyma.