Heparin coating of human breast carcinoma cells in vivo

Mast cells, the only source of heparin in the body, are common in breast carcinoma. Due to metachromatic staining of heparin-proteoglycans released from the mast cells toluidine blue may stain connective tissue a reddish-purple. This study shows that tumour cells in the vicinity may also be coated with metachromatic substance. Such bl vivo coating does not appear to have been reported previously. In experimental studies in vitro coating has been described following suspension of mouse tumour cells in a heparin solution and preincubation of ascitic tumour cells in heparin has given reduction in survival time after transplantation. In human breast carcinoma stromal metachromasia may under certain circumstances be indicative of poor prognosis. The biological implications of in vivo tumour cell coating with heparin are under investigation.