ABSTRACT
Objective To investigate the mechanism of malignant transformation in human bronchial epithelial cell line BEP2D exposed to α-particles.Methods The levels of intracellular ROS and malonaldehyde (MDA) in BEP2D,RH22 (passage 22 of α-particle-irradiated BEP2D cells) and BERP35T-1 cells (derived from nude mice bearing malignant transformed cells generated from the passage 35 of α-particle-irradiated BEP2D cells) were assayed with DCFH-DA and MDA kit,respectively.The expressions of 8-OH-dG and γ-H2AX in BEP2D,RH23 (passage 23 of α-particle-irradiated BEP2D cells)and BERP35T-1 cells were also measured with immunocytochemistry and immunofluorescence staining.Results Compared to BEP2D cells,the levels of ROS ( t =4.30 and 3.94,P ＜ 0.05 ) and MDA ( t =4.89 and 15.10,P ＜0.05) increased in RH22 and BERP35T-1 cells.The expressions of 8-OH-dG (t =3.80 and 2.92,P ＜ 0.05 ) and γ-H2AX ( t =7.61 and 12.67,P ＜ 0.05 ) in RH23 and BERP35T-1 cells were also higher than those in BEP2D cells.Conclusions Oxidative stress induces lipid peroxidation and DNA damage leading to genomic instability,which could contribute to cellular malignant transforming process in the human bronchial epithelial cell line BEP2D with α-particle exposure.
ABSTRACT
capacitation of human sperm is essential for fertilization and is characterized visually by hyperactivated motility. There is a controversy whether reactive oxygen radicals cause infertility or stimulate sperm-zona interaction. We investigated the exact role of reactive oxygen radicals on hyperactivation (HA) of human sperm which could be a part of the capacitation process. Hyperactivation of human sperm was compared to the Ham's F-10 controls by the addition of superoxide anion and hydrogen peroxide generating enzymes on the percale treated sperms. The motility parameters of human sperms were estimated by computer assisted semen analysis system. The addition of xanthine + xanthine oxidase + catalase (generating system of superoxide anion and removal of hydrogen peroxide) on the sperms induced levels of HA (10.5% at 2 hour, 11.3% at 5 hour) which were about 2 times higher than those of controls (HA: 5.4% at 2 hour, 5.6% at 5 hour). The addition of glucose + glucose oxidase (generation of hydrogen peroxide) decreased the levels of HA (0.0% at 2 and 5 hour) significantly. Superoxide dismutase, the scavenger of superoxide anion inhibited HA significantly, whereas catalase, the scavenger of hydrogen peroxide promoted HA significantly These results suggest that the reactive oxygen radicals may be involved in hyperactivation of human sperms by the way that superoxide anion promotes and hydrogen peroxide inhibits hyperactivation of the fertile human sperms. It may be very important in the process of fertilization that promotion or inhibition of hyperactivation occurs at the proper time and location of female genital organ.