Ionic Regulation of Growth in Normal and Tumor Cells
That cellular growth is regulated by intracellular ions such as Na, K, Mg, Ca and H stems from several lines of evidence. Electron probe X-ray microanalysis or EDS gives us the potential to study the relationship between ionic content and growth in cells with carefully characterized growth kinetics. The EDS technique can measure the content of several ions simultaneously at a subcellular level. EDS can be applied both to cells in culture or in vivo. This technique, as with other techniques does not give data on the free or the bound state of the ions measured. EDS has been used to measure elemental concentration differences between rapidly and slowly dividing cell populations and to measure differences between tumor and their non-tumor counterpart cells. We find that increased intracellular Na is related to rapid cell proliferation but show that increased Na is more dramatically related to oncogenesis than to mitogenesis. Our recent results from the injection of amiloride (a drug which blocks the passive influx of Na into mitotically activated mammalian cells) into tumorous mice, indicates that the intranuclear concentration of Na, but not Mg or K is correlated to the proliferative activity of rapidly dividing duodenal crypt enterocytes and also to rapidly proliferating H6 hepatoma cells in mice. That Na but no other ion measured changed in parallel with cell proliferative activity implicates Na in the regulation of cell replication. This finding does not rule out H or other unmeasured ions in the ionic regulation of cell proliferation.
KeywordsTritiated Thymidine Tumor Bearing Mouse Rapid Cell Proliferation Passive Influx Duodenal Crypt
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- 2.Cameron, I.L., N.K.R. Smith, T.B. Pool, B.G. Grubbs, R.L. Sparks and J.R. Jeter, Jr. 1980. In: Nuclear-Cytoplasmic Interactions in the Cell Cycle, G.L. Whitson (ed.), Academic Press, Inc., New York, N.Y. 249.Google Scholar
- 3.Cameron, I.L., N.K.R. Smith, T.B. Pool and R.L. Sparks. 1980. Caner Res. 40: 1493.Google Scholar
- 4.Cameron, I.L.,N.K.R. Smith and P. Skehan. 1983. In: Ions, Cell Proliferation and Cancer, W.L. McKeenan and A. Boyton (eds.) (in press).Google Scholar
- 5.Cameron, I.L. and K.E. Hunter. 1983. Cancer Res.(in press)Google Scholar
- 14.Pool, T.B., I.L. Cameron, N.K.R. Smith and R.L. Sparks. 1981. In: The Transformed Cell, I.L. Cameron and T.B. Pool (eds.), Academic Press, Inc., New York, N.Y. 398.Google Scholar
- 17.Sparks, R.L., T.B. Pool, N.K.R. Smith and I.L. Cameron. 1983 Cancer Res. (in press).Google Scholar