Growth enhancing property of human monocytes from normal donors and cancer patients

Peripheral blood monocytes, but not other leucocytes, from healthy donors, were shown to enhance the DNA synthesis of three cell lines. The effect was very marked on an epithelial (Chang) and lymphoid (CLA-4) cell line derived from normal tissues, and less marked on a carcinoma-derived line (HT-29). The enhancement was demonstrable over a wide range of monocyte:cell line ratios, and some activity was present in supernates from monocytes cultured alone or with a cell line. Furthermore, monocytes from gastric carcinoma patients did not enhance Chang and CLA-4 cells to the same extent, relative to the healthy donors.