This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Forgue-Lafitte, M.-E. Articles by Mester, J. Search for Related Content PubMed PubMed Citation Articles by Forgue-Lafitte, M.-E. Articles by Mester, J.

Proliferation of the Human Colon Carcinoma Cell Line HT29: Autocrine Growth and Deregulated Expression of the c-myc Oncogene¹

Marie-Elisabeth Forgue-Lafitte², Anne-Marie Coudray, Bernadette Bréant and Ján Meter

Institut National de la Santé et de la Recherche Médicale, Unité 55, Centre de Recherches Paris-ST-Antoine, 184, rue du Faubourg St-Antoine, 75012 Paris, France

Human colon adenocarcinoma cells (line HT29) are able to proliferate in a defined (serum-free) medium containing no added growth factors; in such conditions, their doubling time is 3 to 4 days (on serum-coated dishes) or 2 to 3 days (on an autologous extracellular matrix) compared with 1 day in the presence of fetal calf serum. In the presence of suramin, a polyanion disrupting the binding of growth factors to their receptors, the incorporation of [³H]thymidine in serum-free cultures is reduced (27.0 ± 2.9% of control after 3 days of culture), suggesting involvement of autocrine growth factors in the autonomous proliferation of the cells. The expression of the proliferation-related oncogene c-myc was examined during various stages of growth and differentiation of the HT29 cells. The cellular contents of c-myc mRNA were similar in all experimental conditions studied: exponential phase; stationary phase; nondifferentiated as well as differentiated cells (by glucose deprivation); and also in serum-free medium containing or not suramin. An approximately 2-fold increase in the level of c-myc mRNA was observed in cells cultured for 3 days in suramin-containing medium and then incubated during 3 h in the absence of suramin (with or without 10% fetal calf serum). Southern blot analysis of the genomic DNA of HT29 cells did not reveal any rearrangement within the region containing the c-myc gene and the flanking sequences (five kilobases upstream and three kilobases downstream). The c-myc locus was weakly amplified (four to six copies per cell). These results indicate that the c-myc gene expression in HT29 cells is deregulated and does not require growth factor stimulation. The deregulation of the c-myc gene may be related to the reduced growth factor requirement of the HT29 cell line.

¹ This work was supported by INSERM and the Fondation pour la Recherche Médicale Française.

² To whom requests for reprints should be addressed.

Received 2/ 1/89. Revised 8/ 7/89. Accepted 9/ 1/89.

This article has been cited by other articles:

				D. A. Heck and D. B. Bylund Mechanism of Down-regulation of Alpha-2 Adrenergic Receptor Subtypes J. Pharmacol. Exp. Ther., September 1, 1997; 282(3): 1219 - 1227. [Abstract] [Full Text]