ABSTRACT
Objective:To explore the molecular mechanism of cantharidin(CTD) in inducing morphological changes and dissociation in human colon cancer HCT116 cells, in order to study the correlation with tumor metastasis and provide a new basis for clinical use of cantharidin. Method:Different concentrations of CTD (0, 2.5, 5, 10, 15, 20 μmol·L-1) were added to each hole to culture for 7 to 10 days, so as to determine the inhibitory effect of CTD on HCT116 cells; and changes of F-actin cytoskeleton and integrin in HCT116 cells were detected by immunofluorescence staining. Western blot analysis of protein expressions of RhoA,RhoB,RhoC,Cdc42 and Rac1/2/3 of Rho family were performed before and after cantharidin treatment. overexpression of RhoA was constructed by plasmid transient transfection, and effect of 10 μmol·L-1 cantharidin on the morphology and adhesion of overexpressing cells was also observed. Result:Cantharidin induced cytoskeletal remodeling and decreased integrin content in HCT116 colon cancer cells. RhoA protein was a member of Rho enzyme family with the greatest variation after cantharidin action. The proportion of transfected RhoA cells with green fluorescence was about 60%, the expression of RhoA protein in constructed RhoA overexpression cells was significantly increased, compared with wild-type HCT116 cells (PPConclusion:Cantharidin can inhibit the expression of RhoA protein, induce the morphological changes of HCT116 cells and weaken the adhesion to the basement, thereby inhibiting cell migration.
ABSTRACT
This study is to investigate the effect of rhein lysinate on inducing human breast cancer cell line SK-Br-3 apoptosis and the role of HER-2 signal pathway in the apoptosis. MTT assay was used to detect SK-Br-3 cell proliferation. Cell cycle and apoptosis were analyzed by flow cytometry. The protein expression and the protein phosphorylation of HER-2 signal pathway were detected by Western blotting. The level of HER-2 mRNA was detected by RT-PCR and the level of HER-2 expression was also detected by immunofluorescence cytochemical methods. The results showed that rhein lysinate remarkably inhibited breast cancer SK-Br-3 cell proliferation. The IC50 value for 48 h treatment was 85 micromol x L(-1). Apoptosis in SK-Br-3 cells was induced by rhein lysinate in a dose dependent manner. The protein expressions of HER-2, NF-KB, and the protein phosphorylation of HER-2 were downregulated, however the protein expression of p53 and p21 was upregulated after rhein lysinate treatment. The level of HER-2 mRNA decreased by using RT-PCR assay and the level of HER-2 expression was also decreased by using immunofluorescence cytochemical assay after rhein lysinate treatment. It can be concluded that rhein lysinate could inhibit SK-Br-3 cell proliferation and induce apoptosis. HER-2/NF-kappaB/p53/p21 signal pathway might be involved in this process. Rhein lysinate has a good prospect to be an adjuvant chemotherapeutic drug.