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- Barquinero, J-F., et al.
(författare)
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RENEB Inter-Laboratory Comparison 2021 : The FISH-Based Translocation Assay
- 2023
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Ingår i: Radiation Research. - 0033-7587 .- 1938-5404. ; 199:6, s. 583-590
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Tidskriftsartikel (refereegranskat)abstract
- Translocation analysis using fluorescence in situ hybridization (FISH) is the method of choice for dose assessment in case of chronic or past exposures to ionizing radiation. Although it is a widespread technique, unlike dicentrics, the number of FISH-based inter-laboratory comparisons is small. For this reason, although the current Running the European Network of Biological and Physical retrospective Dosimetry (RENEB) inter-laboratory comparison 2021 was designed as a fast response to a real emergency scenario, it was considered a good opportunity to perform an inter-laboratory comparison using the FISH technique to gain further experience. The Bundeswehr Institute of Radiobiology provided peripheral blood samples from one healthy human volunteer. Three test samples were irradiated with blinded doses of 0, 1.2, and 3.5 Gy, respectively. Samples were then sent to the seven participating laboratories. The FISH technique was applied according to the standard procedure of each laboratory. Both, the frequency of translocations and the estimated dose for each sample were sent to the coordinator using a special scoring sheet for FISH. All participants sent their results in due time. However, although it was initially requested to send the results based on the full analysis, evaluating 500 equivalent cells, most laboratories only sent the results based on triage, with a smaller number of analyzed cells. In the triage analysis, there was great heterogeneity in the number of equivalent cells scored. On the contrary, for the full analysis, this number was more homogeneous. For all three samples, one laboratory showed outlier yields compared to the other laboratories. Excluding these results, in the triage analysis, the frequency of translocations in sample no. 1 ranged from 0 to 0.013 translocations per cell, and for samples no. 2 and no. 3 the genomic mean frequency were 0.27 +/- 0.03 and 1.47 +/- 0.14, with a coefficient of variation of 0.29 and 0.23 respectively. Considering only results obtained in the triage analysis for sample no. 1, all laboratories, except one, classified this sample as the non-irradiated one. For sample no. 2, excluding the outlier value, the mean reported dose was 1.74 +/- 0.16 Gy indicating a mean deviation of about 0.5 Gy to the delivered dose of 1.2 Gy. For sample no. 3 the mean dose estimated was 4.21 +/- 0.21 Gy indicating a mean deviation of about 0.7 Gy to the delivered dose of 3.5 Gy. In the frame of RENEB, this is the second FISH-based inter-laboratory comparison. The whole exercise was planned as a response to an emergency, therefore, a triage analysis was requested for all the biomarkers except for FISH. Although a full analysis was initially requested for FISH, most of the laboratories reported only a triage-based result. The main reason is that it was not clearly stated what was required before starting the exercise. Results show that most of the laboratories successfully discriminated unexposed and irradiated samples from each other without any overlap. A good agreement in the observed frequencies of translocations was observed but there was a tendency to overestimate the delivered doses. Efforts to improve the harmonization of this technique and subsequent exercises to elucidate the reason for this trend should be promoted.
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| 4. |
- Mineta, H, et al.
(författare)
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Low expression of fragile histidine triad gene correlates with high proliferation in head and neck squamous cell carcinoma
- 2003
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Ingår i: Oral Oncology. - 1879-0593. ; 39:1, s. 56-63
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Tidskriftsartikel (refereegranskat)abstract
- Frequent loss of heterozygosity in head and neck squamous cell carcinoma (HNSCC) has been found in several chromosomal regions such as 3p, 9p, 11q, 13q and 17p. Fragile histidine triad (FHIT) gene is located at 3p14.2 encompassing a common fragile site, and is identified as a tumor suppressor gene. We examined 57 patients with HNSCC using immunohistochemistry, western blot, and reverse transcriptase polymerase chain reaction. The association between FHIT expression and clinicopathologic characteristics including p53 and Ki-67 expressions was analyzed. Immunohistochemical analysis revealed 30 patients (53%) of low FHIT expression and 27 patients (47%) of high FHIT expression. Low FHIT expression significantly correlated with high Ki-67 expression, indicating that tumor cells with low FHIT expression can proliferate aggressively. No correlation was found between FHIT expression and clinical characteristics including age, gender, tumor size, lymph node status, stage grouping, histologic grade, p53 expression, and prognosis. FHIT alteration may play an important role in cancer development of HNSCC, however it did not contribute to the prognosis. (C) 2002 Elsevier Science Ltd. All rights reserved.
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