Tumour necrosis factor-alpha upregulates transferrin receptors in K 562 cells.
The effects of tumour necrosis factor-alpha on transferrin receptor expression in a human chronic myelocytic leukaemia cell line, K 562 cells, were studied. Cytofluorometry studies showed that the numbers of transferrin receptors in exponentially growing K 562 cells were increased when the cells were incubated with tumour necrosis factor-alpha for 24 h. The induction of transferrin receptors by tumour necrosis factor-alpha may be mediated by a mechanism that is independent of growth since cell growth in treated cultures did not differ from that in the controls. The DNA contents of K 562 cells treated with tumour necrosis factor-alpha showed that after 24 h there were less cells in the G1 and S phases and more cells in the G2/M phase than in the control group. The phase of upregulation of transferrin receptors induced by tumour necrosis factor-alpha may be dependent on the cell cycle. This new evidence that tumour necrosis factor-alpha upregulates transferrin receptors suggests a cancer-anaemia cascade in which the cancer burden state activates macrophage release of tumour necrosis factor-alpha as a result of transferrin receptor expression.
Nezu
M
M
First Department of Surgery, Okayama University Medical School, Japan.
Iwagaki
H
H
Aoki
H
H
Tanaka
N
N
Orita
K
K
D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D005434:Flow Cytometry; D006801:Humans; D011990:Receptors, Transferrin / Q000187:drug effects*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D015854:Up-Regulation
D011990:Receptors, Transferrin; D014409:Tumor Necrosis Factor-alpha