Short Communication Assessment of BCL2/J(H) translocation in healthy individuals exposed to low-level radiation of 137CsCl in Goiânia, Goiás, Brazil

Abstract

ABSTRACT. Healthy radio-exposed individuals who received low levels of Cesium-137 radiation during the accident that occurred in Goiânia in 1987, their families and controls were tested for the detection of t(14;18)-rearranged B cells in peripheral blood by using a highly sensitive, real-time quantitative PCR method. The chromosomal translocation t(14;18)(q32;q21) is characteristic of follicular lymphoma and is a frequent abnormality observed in other types of non-Hodgkin's BCL2/J(H) translocation in exposed individualslymphoma. This translocation leads to constitutive activation of the BCL2 oncogene by the enhancers of the immunoglobulin heavy-chain locus. In healthy individuals, the same translocation may also be found in a small fraction of peripheral blood lymphocytes, and positive cells might serve as an indicator for environmental exposure to carcinogens and possibly correlate with the cumulative risk of developing t(14;18)-positive non-Hodgkin's lymphoma. Twenty healthy radio-exposed individuals, 10 relatives and 10 non-exposed healthy individuals were tested for the detection of this translocation. Only 1 non-exposed individual was positive for the chromosomal translocation, and healthy radio-exposed individuals presented lower levels of cells bearing the BCL2/J(H) rearrangement when compared to the levels of the patients with follicular lymphoma before treatment. However, evaluation of more cells would be required to confirm the total absence of circulating cells bearing BCL2/J(H) rearrangement.

Deviation from mendelian transmission of autosomal SNPs can be used to estimate germline mutations in humans exposed to ionizing radiation

“…However, each biomarker tends to reveal a distinct biological phenomenon in the exposed cells, mostly associated with DNA repair and how cells physiologically coped to survive a specific insult. In this context, our group and others have identified somatic mutations on DNA sequence data from glycophorin A [5] and HPRT [6], general [7,8] and specific chromosomal aberrations, identified by FISH [9] and BCL2/J(H) translocation assays [10], micronucleus presence [11], and assessment of autoimmune markers data (da Cruz et al unpublished data) in the cohort accidently exposed to Cs-137 IR. Moreover, in order to understand the effect of IR on the induction of germ line mutation rates on STR markers [12] have also been determined.…”

Deviation from Mendelian transmission of autosomal SNPs can be used to estimate germline mutations in humans exposed to ionizing radiation

“…However, each biomarker tends to reveal a distinct biological phenomenon in the exposed cells, mostly associated with DNA repair and how cells physiologically coped to survive a specific insult. In this context, our group and others have established somatic mutation frequencies using data from glycophorin A [ 5 ] and HPRT assays [ 6 ], chromosomal aberrations [ 7 – 9 ], BCL2/J(H) translocation [ 10 ], and micronucleus frequencies [ 11 ] in T-lymphocytes of the cohort accidently exposed to Cesium-137 IR. Moreover, in order to understand the effect of IR on the induction of germ line mutations, STR markers [ 12 ] were initially used to estimate the rate of germline mutations in the offspring of the exposed cohort.…”