Cell cycle kinetics and cytogenetic changes in human lymphocytes exposed to oestradiol in vitro

Abstract

Metabolic conversion of oestrogen phenolic groups may create conditions of oxidative stress accompanied by damage of cellular macromolecules including DNA. The aim of this investigation was to evaluate the cell cycle kinetics and possible cytogenetic changes in cultured human peripheral blood lymphocytes exposed to seven experimental concentrations of 17β-oestradiol (range 10-10 M to 10-4 M). Cell cycle kinetics was analyzed on metaphase spreads prepared for a standard analysis of sister-chromatid exchanges (SCEs) stained by fluorescent-plus-Giemsa (FPG) technique. Cytogenetic changes were monitored by analysis of chromosome damage (gaps and breaks), structural and numerical aberrations. On the basis of the obtained results it can be concluded that oestradiol has no significant influence on cell cycle kinetics and mitotic index of cultured human lymphocytes. However, at estradiol concentration of 7×10-6 M, and at higher concentrations used in this experiment, there was a significant increase of gaps, breaks and aneuploidies. On the other hand, oestradiol treatment has not changed the frequency of polyploid cells. Therefore, it can be concluded that high concentrations of oestradiol pose some genetic risk detectable at cytogenetic level.

Metabolička konverzija fenolnih grupa estrogenih hormona može da dovede do oksidativnog stresa praćenog oštećenjima različitih makromolekula u eliji, uključujući DNK. Cilj ovog istraživanja je evaluacija kinetike proliferacije i mogućih citogenetičkih promena u kulturama humanih limfocita pod dejstvom sedam eksperimentalnih koncentracija 17β-estradiola (opseg od 10-10M do10-4 M). Kinetika proliferacije limfocita analizirana je na metafaznim figurama obojenim tehnikom FPG za standardne analize razmena sestrinskih hromatida (SCE). Citogenetičke promene praćene su analizama hromozomskih oštećenja (gapovi i prekidi), strukturnih i numeričkih aberacija hromozoma. Na osnovu dobijenih rezultata može se zaključiti da estradiol ne utiče značajno na mitotsku aktivnost i kinetiku proliferacije limfocita u kulturi. Međutim, pri koncentraciji od 7×10-6 M, kao i pri višim eksperimentalnim koncentracijama korišćenim u ovim eksperimentima, zapažen je porast gapova, prekida i aneuploidija. S druge strane, tretman estradiolom ne menja učestalost poliploidnih ćelija. Prema tome, može se zaključiti da visoke koncentracije estradiola izazivaju izvestan genetički rizik koji se može detektovati na citogenetičkom nivou.