Effect of bleomycin on interstitial telomeric sequences of immortalized Chinese hamster ovary cells

Interstitial telomeric sequences are not preferentially involved in the chromosome damage induced by the methylating compound streptozotocin in chinese hamster cells

“…In good agreement with previous reports [Bolzán et al, 2001;Sánchez et al, 2009Sánchez et al, , 2010Mencucci et al, 2012;Vidal Bravo et al, 2012], cytogenetic analysis of untreated cultures of CHO cells after telomere PNA-FISH showed telomeric repeats, predominantly localized in the centromeric regions of the chromosomes (Fig. 1A).…”

“…We found that radiomimetic compounds are capable of inducing translocation and amplification of ITSs [Bolzán et al, 2001;Sánchez et al, 2009Sánchez et al, , 2010 and also breakage at centromeric regions rich in ITSs; however, these chromosome regions are not the preferential target for the clastogenic action of these compounds [Sánchez et al, 2009[Sánchez et al, , 2010. Because of the presence of large blocks of heterochromatic ITS at centromeric regions on most of the chromosomes, and the fact that about 95% of the telomeric FISH signals in a CHO metaphase cell correspond to ITS, these cells represent an ideal choice for analyzing the behavior of ITS in clastogen-exposed cells [Balajee et al, 1994;Bolzán et al, 2001;Sánchez et al, 2009Sánchez et al, , 2010. In this study, we analyzed the relationship between ITSs and chromosomal aberrations induced by streptozotocin (STZ) in CHO cells 18 h after treatment to obtain further insight into the short-term effects of chemical mutagens on ITSs.…”

“…The CHO cell line was obtained from the Instituto Multidisciplinario de Biología Celular cell repository (La Plata, Argentina) and is an established immortalized cell line derived from CHO cells possessing on average 2n 5 21 [Bolzán et al, 2001;Sánchez et al, 2009Sánchez et al, , 2010. CHO cells were grown in Ham's F10 medium (Sigma Chemical, St. Louis, MO) supplemented with 10% fetal calf serum, penicillin (100 U/ml), and streptomycin (100 lg/ml) at 378C and 5% CO 2 atmosphere.…”

Sister chromatid exchanges and chromosomal aberrations in Chinese hamster ovary (CHO-K1) cells treated with the insecticide pirimicarb

“…Negative controls (untreated cells and solvent vehicle-treated cells) and positive controls (1 g/ml BLM, 1 h-pulse treatment) were run simultaneously with pesticide-treated cultures. BLM was selected due to its capacity of introduce both single-and double-strand breaks into DNA and to induce both CAs and SCEs in different in vitro mammalian cell systems [27][28][29][30][31]. None of the treatments produced significant pH changes in the culture medium.…”

Protective Effect of a Polyherbal Aqueous Extract Comprised ofNigella sativa(Seeds),Hemidesmus indicus(Roots), andSmilax glabra(Rhizome) on Bleomycin Induced Cytogenetic Damage in Human Lymphocytes

“…BLM induces DNA strand breaks, resulting in production of DNA adducts and excess reactive oxygen species (ROS) leading to oxidative stress, mitochondrial leakage, and apoptosis [12]. Bleomycin at a concentration of 40  μ g/mL can induce radiomimetic damage equal to 2 Gy of gamma radiation which is the standard fraction applied daily to cancer patients in fractionation regimes used in radiotherapy [13]. …”