title: Cell growth inhibition and apoptosis by SDS-solubilized single-walled carbon nanotubes in normal rat kidney epithelial cells.
abstract: Carbon nanotubes (CNTs), promising novel nanomaterials, have been applied to drug delivery and bio-imaging; however, their potential harmful effects on human health and environment have gained much attention recently. In the present study, we investigated cytotoxic effect of solubilized single-walled CNTs (SWCNTs), which were dispersed in water by sodium dodesyl sulfate (SDS), in normal rat kidney epithelial cells (NRK-52E). SDS-SWCNT (0.125-10 μg/mL)-treated NRK-52E cells showed decreased cell viability and enhanced cytotoxicity marker levels following 24-48 h incubation. In addition, SDS-SWCNT treatment evoked the cell growth inhibition: 8 μg/mL SDS-SWCNT induced the growth arrest at G(0)/G(1) phase and levels of cell cycle-related proteins such as CDK2, CDK6 and phosphorylated-retinoblastoma (pRB) were significantly reduced by CNT. Whereas, at higher concentration of SDS-SWCNT, the percentage of cell numbers in apoptotic sub-G(1) phase was substantially increased. Along with these changes, SDS-SWCNT treatment elevated protein levels for p53 and p21 with a concomitant increase in the single strand DNA breakage. Taken together, these results suggest that SDS-solubilized SWCNTs exert genotoxic effect in renal epithelial cells, and p53-dependent signaling can be associated with the growth arrest and apoptosis events upon CNT-induced DNA damage.
authors.affiliation: College of Pharmacy, Yeungnam University, Gyeongsan-si, Gyeongsangbuk-do, 712-749, Korea.
authors.forename: Chang-Won
authors.initials: CW
authors.lastname: Nam
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Kang
authors.forename: Youn Kyung
authors.initials: YK
authors.lastname: Kang
authors.forename: Mi-Kyoung
authors.initials: MK
authors.lastname: Kwak
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D018929:Cell Culture Techniques; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D037742:Nanotubes, Carbon / Q000737:chemistry / Q000633:toxicity*; D051381:Rats; D016160:Retinoblastoma Protein / Q000378:metabolism; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D018797:Cell Cycle Proteins; D037742:Nanotubes, Carbon; D016160:Retinoblastoma Protein; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate