Abstract
In the previous report (Porter et al., in this issue) morphological changes in Chinese hamster ovary (CHO) cells during the cell cycle were described. In this report we describe the role of intercellular contact on these changes. We find that intercellular contact is required for cells to exhibit the morphologies Porter et al. described for S and G2. When cells are synchronized by mitotic selection and plated onto cover slips at very low density such that no intercellular contact occurs, the cells remain in a G1 configuration (rounded and highly blebbed through G1, S, and G2). This G1 morphology is also observed in nonsynchronized log phase cells plated at low densities and allowed to grow for several generations. The addition of conditioned medium from confluent cultures does not induce low density cells to change morphology during the cell cycle. These results indicate that extensive intercellular contact is required for the complete expression of the morphological changes associated with the cell cycle (as described by Porter et al.). It is concluded that although classic contact inhibition of movement and of growth may be absent in this transformed cell line, some contact-dependent response persists.
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Selected References
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- Everhart L. P. Effects of deprivation of two essential amino acids on DNA synthesis in Chinese hamster cells. Exp Cell Res. 1972 Oct;74(2):311–318. doi: 10.1016/0014-4827(72)90382-5. [DOI] [PubMed] [Google Scholar]
- Follett E. A., Goldman R. D. The occurrence of microvilli during spreading and growth of BHK21-C13 fibroblasts. Exp Cell Res. 1970 Jan;59(1):124–136. doi: 10.1016/0014-4827(70)90631-2. [DOI] [PubMed] [Google Scholar]
- O'Neill C. H., Follett E. A. An inverse relation between cell density and the numner of microvilli in cultures of BHK 21 hamster fibroblasts. J Cell Sci. 1970 Nov;7(3):695–709. doi: 10.1242/jcs.7.3.695. [DOI] [PubMed] [Google Scholar]
- Otten J., Johnson G. S., Pastan I. Cyclic AMP levels in fibroblasts: relationship to growth rate and contact inhibition of growth. Biochem Biophys Res Commun. 1971 Sep;44(5):1192–1198. doi: 10.1016/s0006-291x(71)80212-7. [DOI] [PubMed] [Google Scholar]
- PUCK T. T., CIECIURA S. J., ROBINSON A. Genetics of somatic mammalian cells. III. Long-term cultivation of euploid cells from human and animal subjects. J Exp Med. 1958 Dec 1;108(6):945–956. doi: 10.1084/jem.108.6.945. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Porter K., Prescott D., Frye J. Changes in surface morphology of Chinese hamster ovary cells during the cell cycle. J Cell Biol. 1973 Jun;57(3):815–836. doi: 10.1083/jcb.57.3.815. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Puck T. T., Waldren C. A., Hsie A. W. Membrane dynamics in the action of dibutyryl adenosine 3':5'-cyclic monophosphate and testosterone on mammalian cells. Proc Natl Acad Sci U S A. 1972 Jul;69(7):1943–1947. doi: 10.1073/pnas.69.7.1943. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tobey R. A., Anderson E. C., Petersen D. F. Properties of mitotic cells prepared by mechanically shaking monolayer cultures of Chinese hamster cells. J Cell Physiol. 1967 Aug;70(1):63–68. doi: 10.1002/jcp.1040700109. [DOI] [PubMed] [Google Scholar]