Enhancement of Sister Chromatid Exchanges in Peripheral Blood Lymphocytes of Thyroid Cancer Patients in Vitro

Abstract

Abstract:The aim of our study was to determine the chromosomal fragility of thyroid cancer patients in vitro. The cytogenetic methodology used in our study, was the SCEs (sister chromatid exchanges technique). FPG (fluorescence plus giemsa) method, was used in order to dye chromosomes. PRI (proliferation rate index), MI (mitotic index), AGT (average generation time) and PDT (population doubling time) were also counted. CPT-11 (Irinotecan), an original alkyliotic agent, was used in our experiments as a positive control. Samples from 19 thyroid cancer patients and 13 healthy donors were controlled. The levels of SCEs were analyzed as a quantitative index of genotoxicity and the PRI and the MI were estimated as qualitative indices of cytostaticity and cytotoxicity, respectively. After CPT-11 addition in human lymphocytes cultures, the chromosomes of the cancer patients had a significant increase of the mean SCEs frequency. PRI and MI of treated with CPT-11 and untreated lymphocytes of thyroid cancer patients were significantly lower than those of healthy donors. The results suggested that peripheral lymphocyte chromosomes of cancer patients are highly fragile and the alkyliotic agents increase their genetic instability. It appears that the increased SCE levels in peripheral blood lymphocyte chromosomes of thyroid cancer patients often result in chromosomal brittleness.