The use of EBV-transformed cell lines of breast cancer patients to measure chromosomal radiosensitivity (original) (raw)
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The use of IL-2 cultures to measure chromosomal radiosensitivity in breast cancer patients
Mutagenesis, 2004
Enhanced chromosomal radiosensitivity in breast cancer patients has been demonstrated in several studies. To investigate the chromosomal radiosensitivity of lymphocytes in breast cancer patients the G 2 and micronucleus (MN) assays are often used. In these assays blood samples are exposed to ionizing radiation and the number of radiationinduced micronuclei or chromatid breaks are scored. In most studies investigating the in vitro chromosomal radiosensitivity of breast cancer patients the G 2 and MN assays were performed on freshly drawn blood. The disadvantage of working with fresh blood samples is that in most cases only one blood sample can be obtained and that the assay cannot be easily repeated without further blood sampling. To allow repeated testing we propose the use of long-term cultures of T lymphocytes (IL-2 cultures). In this study we therefore investigated whether the radiation-induced MN response in IL-2 cultures was the same as in concordant whole blood cultures. For this study the MN assay (2 Gy) was performed on IL-2 cultures of 11 sensitive breast cancer patients and 20 healthy women. The results demonstrate that the enhanced chromosomal radiosensitivity observed in whole blood cultures of breast cancer patients is not present in IL-2 cultures derived from the same blood samples. Therefore, care has to be taken when IL-2 cultures are used to assess chromosomal radiosensitivity in breast cancer patients.
International Journal of Radiation Oncology*Biology*Physics, 2002
Purpose: Stable chromosomal aberrations (SCAs) have been found in circulating lymphocytes from patients treated for breast carcinoma. Therefore, we tried to define their incidence in such patients, to determine an in vitro dose-effect relationship, and to correlate these data with clinical parameters. Methods and Materials: This prospective study included 25 patients who, after surgery, underwent either radiotherapy (RT) alone (n ؍ 15) or RT combined with chemotherapy (n ؍ 10). SCAs were scored using the fluorescent in situ hybridization technique before RT and 4 and 12 months after RT. Dose-effect curves were established by in vitro irradiation of blood samples with 2 and 4 Gy, before and after treatment. Results: In all patients, the rate of SCAs increased significantly after external irradiation. No significant decrease in SCAs was observed during the first year after RT. RT and chemotherapy had no effect on the lymphocyte in vitro dose-effect relationship. No relationship was found in the distribution of patients between the yield of SCAs scored after external irradiation and after in vitro irradiation. SCAs after RT or in vitro irradiation did not correlate with family history of breast carcinoma or acute toxicity of treatment. More significantly, the yield of SCA after external irradiation was strongly related to the irradiation of the internal mammary chain and the supraclavicular lymph node area, suggesting that the volume of irradiated blood vessels was an essential parameter in determining the rate of SCAs. Conclusion: A high and stable yield of SCAs persisted at least 1 year after external irradiation. The nature of the volume irradiated containing large blood vessels was the major determinant of the observed biologic dose.
Chromosomal radiosensitivity in breast cancer patients: influence of age of onset of the disease
Oncology Reports
The age dependency of onset of the disease on chromosomal radiosensitivity of an unselected group of breast cancer patients (n=100) was investigated and compared to a group of healthy women (n=100). The chromosomal radiosensitivity was assessed with the G2 and the G0 micro-nucleus (MN) assay. For the G2 assay lymphocytes were irradiated in vitro with a dose of 0.4 Gy 60Co gamma-rays after 70 h incubation and chromatid breaks were scored in 50 metaphases. For the G0 MN assay lymphocytes were exposed in vitro to 3.5 Gy 60Co gamma-rays at low dose rate (LDR). 72 h post-irradiation cultures were arrested and micronuclei were scored in 1000 binucleate cells. The results demonstrated that the group of breast cancer patients was more radiosensitive than a population of healthy women and this with both the G2 and the G0 MN assay. Analyses of the G2 and MN response in different age groups of the breast cancer patients revealed no significant differences in mean G2 and MN scores and suggest t...
Journal of Radiation Research, 2005
Enhanced chromosomal radiosensitivity is a feature of many cancer predisposition conditions, indicative of the important role of chromosomal alterations in carcinogenesis. In this study the cytokinesisblocked micronucleous assay was used to compare the radiosensitivity of blood lymphocytes obtained from Iranian breast or esophageal cancer patients (n = 50, n = 16; respectively) with that of control individuals (n = 40). For each sample, one thousand binucleate lymphocytes were analyzed before and after in vitro exposure to 3 Gy of g rays. The radiation-induced frequency of micronucleus was significantly higher in the breast cancer group (261/1,000 binucleated cells) than in esophageal cancer group (241/1,000 binucleated cells, P < 0.01) or in the control group (240/1,000 binucleated cells, P < 0.01). The results indicate that breast cancer patients are more radiosensitive compared to normal healthy individuals or esophageal cancer patients. Increased radiosensitivity could be due to defects in DNA repair genes involved in breast cancer formation. Since patients with esophageal cancer did not show elevated radiosensitivity, it is assumed that the contribution of radiosensitivity-related genes to the development of esophageal cancer may be smaller than the contribution of those genes to breast cancer.
Chromosomal Sensitivity to Ionising Radiation in Lymphocytes of Patients with Head and Neck Cancer
Basic & Clinical Cancer Research, 2015
Purpose: The aim of this study was to test the in vitro sensitivity of lymphocytes of patients with head and neck cancer against gamma irradiation and also to find out if the frequencies of chromosomal aberrations correlate with side effects of radiotherapy. Patients and Methods : Peripheral blood of 101 patients with head and neck cancer was collected before the onset of radiotherapy, cultured and irradiated in the G2- or the G0- phase of the cell cycle. Lymphocytes of 40 healthy donors were treated in the same way. Chromosomal aberrations such as chromosome and chromatid breakages, chromosome and chromatid gaps, chromatid exchanges and micronuclei were scored in metaphase cells of the patient and control groups. Results: The frequency of radiation- induced G2 aberrations in lymphocytes of patients were on average higher than in those of healthy donors ( P =0.001 for chromosomal breaks). The frequency of radiation-induced micronuclei in the G0 assay were also higher in patients th...
Lymphocytes of Breast and Esophageal Cancer Patients as Determined by Micronucleus Assay
2016
Radiosensitivity/Human lymphocytes/Breast cancer/Esophageal cancer/Micronuclei. Enhanced chromosomal radiosensitivity is a feature of many cancer predisposition conditions, indic-ative of the important role of chromosomal alterations in carcinogenesis. In this study the cytokinesis-blocked micronucleous assay was used to compare the radiosensitivity of blood lymphocytes obtained from Iranian breast or esophageal cancer patients (n = 50, n = 16; respectively) with that of control indi-viduals (n = 40). For each sample, one thousand binucleate lymphocytes were analyzed before and after in vitro exposure to 3 Gy of g rays. The radiation-induced frequency of micronucleus was significantly higher in the breast cancer group (261/1,000 binucleated cells) than in esophageal cancer group (241/1,000 binucleated cells, P < 0.01) or in the control group (240/1,000 binucleated cells, P < 0.01). The results indicate that breast cancer patients are more radiosensitive compared to normal heal...
International Journal of Radiation Oncology*Biology*Physics, 2003
Purpose: To measure chromosomal aberrations in blood lymphocytes from breast cancer patients treated with radiotherapy after quadrantectomy or tumorectomy. Methods and Materials: Twenty-two breast cancer patients treated with breast-conserving surgery and radiation were evaluated. Adjuvant chemotherapy was also given to 9 patients. Blood samples were obtained before radiotherapy, after about one-half of the fractions, and at the end of the treatment of the whole breast (50 Gy). Chromosome aberrations in peripheral blood lymphocytes were measured using chemical-induced premature chromosome condensation combined with fluorescence in situ hybridization. Results: Radiation treatment produced a significant increase in the yield of chromosomal aberrations. A large interindividual variability was observed. The variability was not related to field size, previous chemotherapy, or treatment morbidity. Chromosome aberrations in lymphocytes at the end of the treatment were significantly higher in the group of patients with no lymph nodes surgically removed before the treatment than in the group of patients with more than 10 lymph nodes removed. Conclusions: The number of lymph nodes within the radiation field is an important factor affecting the yield of radiation-induced chromosomal aberrations in breast cancer patients.
2017
Background: About 83% of patients with breast cancer (BC) undergo radiation therapy. These patients show various degrees of mild to acute reactions during and after the completion of treatment.The aim of this study was to compare inherent radiosensitivity of gamma-irradiated G0-lymphocytes between BC patients and normal individuals using cytokinesis blocked micronucleous assay.Methods: Three to 4 mL blood was drawn in heparinized syringes from patients and normal individuals. A portion of the sample was irradiated with gamma rays at a dose of 300 cGy. Irradiated and non-irradiated samples were cultured in complete RPMI-1640 culture medium. A standard cytokinesis-blocked micronucleus assay protocol was followed for the preparation of binucleate lymphocytes. Slides were prepared and stained in Giemsa. Thousand binucleate cells were scored for the presence of micronucleus (MN). Data were statistically analyzed using SPSS software.Results: The results showed that the background frequenc...
Neoplasma, 2008
The reliability of a particular in vitro parameter as potential prognostic biomarker of individual radiosensitivity is still discussed. Therefore, several in vitro radiation-induced cellular endpoints including initial, oxidative and residual DNA damage and the rate of DNA repair were assessed in peripheral blood lymphocytes (PBL) from healthy donors and patients with carcinoma of the cervix using the alkaline single cell gel electrophoresis (the comet assay). PBL from cancer patients were analyzed three times during the course of therapy, prior, in the middle (25-27 Gy) and after the radiotherapy. Interindividual differences in radiation-induced DNA damage and in the kinetics of strand break rejoining were determined within both groups. Significantly higher level of mean background and oxidative DNA damage was estimated in the cancer patient cohort than in the healthy subject group; however similar mean values of the initial DNA damage and the rate of DNA repair kinetics were found...
International Journal of Radiation Research
Background: There is not yet an appropriate biomarker to predict or follow radiosensitivity of Breast cancer (BC) patients during or after radiotherapy. The aim of this study was to monitor chromosomal aberrations (CA) induced before and during radiotherapy in peripheral blood lymphocytes of BC patients. Materials and Methods: Age-matched twenty normal healthy individuals and 20 invasive ductal BC patients were enrolled in this study. A blood sample was obtained from normal healthy women and BC patients before and after the first, two and four weeks after radiotherapy. Lymphocyte microculture was initiated in 4.5ml complete RPMI-1640 medium. Cells were harvested 50 hours after culture initiation. Cells were harvested based on standard protocols. Hundreds of well-spread mitoses were scored under a light microscope with a magnification of x1000 for various types of CA. Data were statistically analyzed and p<0.05 was considered a significant difference. Results: Results indicated a higher frequency of CA in lymphocytes of un-irradiated BC patients compared to healthy normal individuals, although not statistically significant (p>0.05). High frequencies of CA were observed in lymphocytes of BC patients after radiotherapy, significantly different from the un-irradiated group (p<0.01). The increase in the frequency of CA was increased with increasing radiation dose. Conclusion: Genome instability may contribute to high background and radiationinduced CA in lymphocytes of BC patients. However, there is also the possibility of a radio-adaptation of cells during the course of radiotherapy. Results imply that dicentric chromosomes might be valuable cytogenetic bioindicators to monitor the response of BC patients to radiotherapy.