title: Dimethylformamide-induced changes in the radiation survival of low- and high-passage intestinal epithelial cells (IEC-17) in vitro.
abstract: The effects of dimethylformamide (DMF) on the radiation response of low- and high-passage intestinal epithelial cells (IEC-17) were examined. The IEC-17 cell line, a rat intestinal epithelial cell line, exhibited a bimodal response to X radiation. The sensitive fraction, which was attributed to a stem cell-like component, had a D0 of 0.90 Gy. The resistant fraction, thought to be the expression of a more mature component, exhibited a D0 of 2.00 Gy. Treatment using a putative cell differentiating agent, N,N-dimethylformamide, increased the resistant fraction of the population from 35 to 80%, suggesting that DMF treatment (100 mM) increased the proportion of mature cells in the IEC-17 cell population. In addition, extended age in culture (greater than 100 passages) resulted in altered morphology, decreased doubling time, increased chromosome number, and loss of anchorage dependence, all features characterizing spontaneously transformed high-passage IEC-17 cells. These high-passage cells also exhibited a bimodal response to X radiation; the sensitive fraction had a D0 of 0.80 Gy while the resistant fraction D0 was 1.50 Gy. DMF increased the resistant fraction from 35 to 55% of the population. Results suggested that the different radiosensitivities of the subpopulations remained throughout the spontaneous transformation of high-passage IEC-17 cells.
authors.affiliation: Radiation Research Laboratory, University of Iowa, Iowa City 52242.
authors.forename: C
authors.initials: C
authors.lastname: DeRose
authors.forename: H G
authors.initials: HG
authors.lastname: Claycamp
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D004126:Dimethylformamide / Q000494:pharmacology*; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000528:radiation effects; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000166:cytology* / Q000187:drug effects / Q000528:radiation effects; D051381:Rats
chemical_list: D004126:Dimethylformamide