RESUMEN
@#Objective To investigate the effect of artesunate inhibiting the expression of FOXP3 on proliferation, apoptosis and multidrug resistance of adriamycin (ADR) -resistant K562/ADR cells in chronic myeloid leukemia (CML), and to explore its mechanism. Methods The expressions of FOXP3 mRNA in K562 and K562/ADR cells were detected by real-time PCR. The expressions of FOXP3 proteins in K562 and K562/ADR cells were detected by Western blot assay. The K562/ADR cells were treated with different concentrations of artesunate (2.5, 5.0, 7.5, 10.0 and 12.5 mg/L) for 24 h. The toxicities of different concentrations of artesunate to K562/ADR cells were detected by CCK-8 assay, and the non-cytotoxic concentrations were screened. The expressions of FOXP3 mRNA and proteins in K562/ADR cells treated by non-cytotoxic concentration of artesunate were detected by RT-PCR and Western blot assay. The changes of toxicities of ADR in K562/ ADR cells were detected by CCK-8 assay. The average fluorescence intensities of ADR were detected by FCM assay. Results The expressions of FOXP3 were higher in K562/ADR cells than those in K562 cells. The mRNA and proteins expressions of FOXP3 were significantly lower in 2.5 mg/L group, 5 mg/L group and 7.5 mg/L group than those in the control group. The toxicities and concentrations of ADR were increased in K562/ADR cells treated by artesunate (both P＜0.05). Conclusion FOXP3 gene is highly expressed in adriamycin-resistant K562/ADR cells in CML. Artesunate can increase the concentrations of ADR and reverse multidrug resistance in K562/ADR cells by inhibiting the expression of FOXP3 in a dose-dependent manner.
RESUMEN
The purpose of the present study was to investigate the effect of advanced glycated albumin (AGE-alb) on the activation of caspase-12, a key molecule in endoplasmic reticulum stress (ERS)-associated apoptotic pathway, and to elucidate the underlying molecular mechanisms of macrophage apoptosis. RAW264.7 macrophages were treated with AGE-alb (2, 4 and 6 g/L), control albumin (C-alb, 4 g/L), tunicamycin (TM, 4 mg/L), or pretreated with 4-phenylbutyric acid (PBA, 5 mmol/L) for 1 h and then treated with AGE-alb (4 g/L). After incubation for 24 h, the cell viability and apoptosis were determined by using MTT assay and TUNEL detection kit, respectively. Lactate dehydrogenase (LDH) activity in media was determined by using an assay kit. The protein levels of caspase-12 were examined by Western blot analysis. The results showed that like TM (an ERS inducer), incubation with AGE-alb led to significant decrease in viability and increase in LDH activity in media and apoptotic rate in a dose-dependent manner. In addition, AGE-alb induced activation of caspase-12 especially at the concentration of 4 and 6 g/L (P < 0.01), which was similar to TM. However, PBA (an ERS inhibitor) protected RAW264.7 macrophages from AGE-alb-induced decrease in viability and increases in LDH activity and apoptosis. Moreover, PBA also inhibited the caspase-12 activation induced by AGE-alb (P < 0.05). These results suggest that AGE-alb may induce apoptosis in RAW 264.7 macrophages, and the mechanism may be related to the activation of ERS-associated apoptotic pathway mediated by caspase-12.