ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of 0.1 Gy X-ray irradiation on the gene expression profiles in normal human lymphoblastoid cells using gene microarray and to explore the possible mechanism of the biological effect of low-dose irradiation.</p><p><b>METHODS</b>The NimbleGen 12×135 K microarray corresponding to 45033 genes was used to analyze the gene expression profiles in AHH-1 cells cultured for 6 h and 20 h after 0.1 Gy X-ray irradiation. A gene was identified as the differentially expressed gene if the ratio between its expression levels in irradiation group and control group was higher than 2 or lower than 0.5. RT-PCR and real-time PCR were used to confirm some differentially expressed genes.</p><p><b>RESULTS</b>There were 760 up-regulated genes and 1222 down-regulated genes in the cells at 6 h after 0.1 Gy X-ray irradiation, while there were 463 up-regulated genes and 753 down-regulated genes at 20 h after 0.1 Gy X-ray irradiation; there were 92 differentially expressed genes in common. The expression of GADD45A, CDKN2A, and Cx43 measured using gene microarray was confirmed by RT-PCR and real-time PCR.</p><p><b>CONCLUSION</b>Low-dose irradiation can affect the expression of many functional genes, which provides a basis for the research on the mechanism of radiation damage.</p>
Subject(s)
Humans , Cell Line , Lymphocytes , Radiation Effects , Oligonucleotide Array Sequence Analysis , Radiation Dosage , Radiation, Ionizing , Transcriptome , X-RaysABSTRACT
<p><b>OBJECTIVE</b>To establish the dose-effect curve between TCR MF and ionizing radiation.</p><p><b>METHODS</b>Peripheral lymphocytes were collected from 8 healthy adults (4 males and 4 females) and cultured in vitro with 12 well culture plates. They were stimulated by PHA-P and IL-2 after exposed to different doses of irradiation (0.00 - 8.00 Gy) and cultured for 7 d. The dose-effect curve was established after measuring TCR MF using flow cytometry. Also, using the same method, we separated and cultured the peripheral lymphocytes collected from 16 radiotherapy cancer patients, whose radiation styles and doses were different, and then measured TCR MF to estimate the whole equivalent dose of radiotherapy patients through the dose-effect curve. Peripheral blood was collected and cultured, chromosome aberration (dicentric and ring) was determined under microscope to estimate irradiation dose.</p><p><b>RESULTS</b>The relationship of dose-effect between the TCR MF and ionizing radiation (0.00 - 8.00 Gy) was well, the curve of large dose group (2.00 - 8.00 Gy), low dose group (0.00 - 1.00 Gy) and 0.00 - 8.00 Gy dose group were met with the quadratic polynomial model, the equation was TCR MF = -32.8579 + 20.5436D + 0.6341D(2), TCR MF = 1.796 + 0.017D + 5.155D(2) and TCR MF = -0.6229 + 6.305D + 0.6919D(2), respectively. D was the radiation dose (Gy). Using the established curve and the chromosome aberration method to estimate the systemic exposure dosage, the average relative deviation was 16.8%.</p><p><b>CONCLUSION</b>The curve established by the TCR gene mutation analysis technology can be applied to exposure dose estimation of victims in ionization radiation accidents.</p>