Effects of camptothecin on the autophagy of HaCaT cells / 中华皮肤科杂志

ABSTRACT

Objective To evaluate effects of camptothecin on the autophagy of HaCaT cells.Methods Some cultured HaCaT cells were divided into several groups to be treated with camptothecin at concentrations of 5,10,25,50,100 and 200 nmol/L,and 0.1％ dimethyl sulfoxide (DMSO) (control group),respectively.Cell counting kit-8 (CCK-8) assay was conducted to estimate the proliferative activity of HaCaT cells after 24-and 48-hour treatment,flow cytometry to evaluate cell apoptosis after 24-hour treatment,and Western blot analysis to measure the expression of autophagy-related proteins microtubuleassociated protein 1 light chain 3 (LC3) and p62.Some HaCaT cells were divided into 2 groups to be treated with 10 nmol/L camptothecin and 0.1％ DMSO for 24 hours,respectively.Then,indirect immunofluorescence assay (IFA) was performed to determine the LC3 expression.Results Camptothecin at low concentrations of 5 and 10 nmol/L had no significant effects on the proliferation and apoptosis of HaCaT cells.Compared with the control group,the cellular proliferative rates were significantly inhibited by (31.23 ± 1.00)％,(54.21 ± 8.10)％ and (66.75 ± 10.70)％ in the 50-,100-and 200-nmol/L camptothecin groups after 24-hour treatment respectively,and by (25.81 ± 5.99)％,(44.35 ± 5.32)％,(65.81 ± 8.28)％ and (73.23 ± 9.59)％ in the 25-,50-,100-and 200-nmol/L camptothecin groups after 48-hour treatment respectively (all P ＜ 0.001).After 24-hour treatment,the apoptosis rates were significantly higher in the 50-,100-and 200-nnol/L camptothecin groups (14.46％ ± 2.38％,19.15％ ± 1.59％,29.88％ ± 1.37％,respectively) than in the control group (3.80％ ± 0.13％,all P ＜ 0.001).After 24-hour treatment with 5 and 10 nmol/L camptothecin,the protein expression of LC3 Ⅱ was significantly up-regulated,while p62 protein expression was significantly down-regulatedIFA showed that the percentage of autophagosome-positive cells was significantly higher in the 10-nmol/L camptothecin group than in the control group after 24-hour treatment (36.67％ ± 4.55％ vs.6.23％ ± 0.92％,t =6.546,P =0.003).Conclusions Camptothecin at low concentrations of 5 and 10 nmol/L can induce autophagy of HaCaT cells,but has no obvious effects on cell proliferation and apoptosis.Camptothecin at concentrations of 50,100 and 200 nmol/L can inhibit cell proliferation,promote cell apoptosis,and decrease autophagy levels.