Abstract
We have succeeded in long-term cultivation of a human erythroleukemia cell line, K-562-T1 (T. Okabe, M. Fujisawa, and F. Takaku, Proc. Natl. Acad. Sci. USA, 81: 453–455, 1984). The cells grown in a protein-free chemically defined medium have been shown to produce cell growth factors (A. Mihara et al., In Vitro Cell. Dev. Biol., 23: 317–322, 1987). In this study, we have purified a cell growth factor from the conditioned medium that stimulates the proliferation of human leukemia cells, HL-60. In the purified factor, two major protein bands of 24 kDa and 22 kDa were identified on a sodium dodecyl sulfate-polyacrylamide gel. The 22 kDa protein was stained with a monoclonal antibody to the light chain of ferritin. The growth-promoting activity of the purified factor was coprecipitated with a monoclonal antibody to the light chain or heavy chain of human ferritin. These results suggest that K-562-T1 cells produce a cell growth factor that is related to ferritin.
Footnotes
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↵1 This work was supported in part by The Nomura Foundation.
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
- Received July 19, 1993.
- Accepted November 1, 1993.
- ©1994 American Association for Cancer Research.
Volume 54, Issue 1
