Skin fibroblast cell lines derived from non‐hodgkin's‐lymphoma (NHL) patients show increased sensitivity to chronic gamma irradiation

Abstract

Cultured fibroblast cells from 19 patients with non-Hodgkin's lymphoma (NHL), 3 patients with ataxia telangiectasia (AT), 3 AT heterozygotes and 11 (presumed) normal subjects were studied for impaired colony-forming ability after chronic gamma irradiation. Five cell lines from the NHL patients were also examined for the sensitivity to acute gamma irradiation, as compared with those of normal subjects. To ascertain the degree of radiosensitivity of different cell lines, a comparison was made of the D10 values (radiation dose resulting in 10% survival) for each cell line, estimated "by eye" from the actual survival curves, and also from the calculated curves fitted to a log-linear model. It was observed that the acute gamma irradiation failed to show any appreciable difference in the radiation response of the cell lines from NHL patients as compared with those of normal subjects. However, chronic irradiation demonstrated significantly increased radiosensitivity in at least 10-12 NHL patients with a p value of less than 0.05, when the D10 values of each patient's cell line were compared with the calculated composite values for the normals. When the D10 values of the NHL patients and the normal subjects were compared as 2 groups, the former appeared to be significantly more sensitive to chronic gamma irradiation (p less than 0.0001). The same level of significant difference in radiosensitivity was found between the 2 groups when their D37 values (radiation dose resulting in 37% survival) were compared. In general, the radiation response of the NHL patients was similar to that of the AT homozygotes and heterozygotes used as a positive control group. Our data thus show that increased radiosensitivity is associated with the NHL patients studied, indicating an underlying abnormality of their DNA repair.

Increased Chromosomal Aberration and Expression of Specific Breakpoints after Chronic Irradiation of Fibroblasts from a Patient with Non-Hodgkin's Lymphoma

“…Chromosome analysis in each cell line was performed on 100 (coded) banded metaphases at each radiation dose-point. Breaks and rearrangements (i.e., rings, translocations, inversions, dicentrics) were scored as chromosome aberrations, and the Karyotypic analysis was performed as defined by ISCN (1985) nomenclature.An increased sensitivity of fibroblast cell lines from NHL patients to chronic gamma-irradiation has been already reported [5]. Figure 1 illustrates the survival curves obtained after chronic irradiation of cultured fibroblasts from one NHL patient, one AT patient and a normal subject used in the present study.…”

“…We have recently reported that skin fibroblast cell lines from most of the Saudi patients with non-Hodgkin's lymphoma (NHL) showed increased sensitivity to chronic gamma irradiation [5]. In the present study, we examined one of these radiosensitive cell lines (L 213725) for chromosomal aberration and specific breakpoints after chronic irradiation compared to the cell lines from a normal subject and an AT patient.…”

“…These findings stimulated a great deal of interest in exploring the usefulness of in vitro cellular radiosensitivity for the identification of cancer-prone individuals. While cell lines from several cancer-prone disorders other than AT and XP and also some cancer patients have been isolated and their in vitro cellular radiosensitivity demonstrated [4,5] little effort has been made in showing the genetic connection between carcinogen-sensitivity and cancer risks by analyzing chromosomal and mutational alterations in these cells.We have recently reported that skin fibroblast cell lines from most of the Saudi patients with non-Hodgkin's lymphoma (NHL) showed increased sensitivity to chronic gamma irradiation [5]. In the present study, we examined one of these radiosensitive cell lines (L 213725) for chromosomal aberration and specific breakpoints after chronic irradiation compared to the cell lines from a normal subject and an AT patient.…”

“…These findings stimulated a great deal of interest in exploring the usefulness of in vitro cellular radiosensitivity for the identification of cancer-prone individuals. While cell lines from several cancer-prone disorders other than AT and XP and also some cancer patients have been isolated and their in vitro cellular radiosensitivity demonstrated [4,5] little effort has been made in showing the genetic connection between carcinogen-sensitivity and cancer risks by analyzing chromosomal and mutational alterations in these cells.…”

“…Skin fibroblast cell lines developed from cutaneous biopsies obtained from NHL and AT patients as well as normal subjects have been described [5], Early passage (4-10) cells were grown in Ham's F12 medium supplemented with glutamin (2mM), penicillin (100 µg/ml) and 10-15% fetal bovine serum in 100 mm tissue culture plates, and incubated at 37°C in a humidified (80%) atmosphere with 5% CO 2 , 95% air. Cells from the exponential growth phase were harvested, replated in F12 medium and grown to confluence.…”