ABSTRACT
ObjectiveTo investigate effect of aqueous extract of Trametes robiniophila （TRM，Huaier） on autophagy of human prostate cancer VCaP cells and Lamin B1 expression， so as to uncover its role in the proliferation of VCaP cells. MethodThe inhibitory effect of 0， 2， 4， 6， 8， 10 g·L-1 TRM aqueous extract on the proliferation of human prostate cancer VCaP cells at different time points were determined by cell counting kit-8 （CCK-8） assay. Acridine orange staining was conducted for analyzing the effect of TRM aqueous extract on the formation of autolysosomes in VCaP cells. After medication， the expression of microtubule-associated protein Ⅰ light chain 3 （LC3）， autophagy-related protein 3 （Atg3）， autophagy-related protein 5 （Atg5）， and autophagy-related protein 7 （Atg7） in VCaP cells were detected by Western blot. The effect of TRM aqueous extract alone and its combination with autophagy inhibitor bafilomycin A1 on the proliferation of VCaP cells were assayed by CCK-8 assay. RNA interference technology was used to explore the role of Lamin B1 in anti-proliferation of VCaP cells by TRM. ResultCompared with the blank group， TRM aqueous extract inhibited the proliferation of human prostate cancer VCaP cells in a time- and concentration-dependent manner （P<0.01）. Acridine orange staining showed that TRM aqueous extract promoted the formation of autolysosomes in VCaP cells. As revealed by Western blotting， TRM aqueous extract up-regulated the expression levels of LC3-Ⅱ， Atg3， Atg5， and Atg7 in contrast to those in the blank group （P<0.05）. All these indicated that TRM aqueous extract induced the autophagy of VCaP cells. In addition， autophagy inhibition impaired the sensitivity of VCaP cells to TRM aqueous extract （P<0.05）. The comparison with the blank group showed that TRM aqueous extract inhibited Lamin B1 protein expression in VCaP cells （P<0.01）， which in turns weakened the sensitivity of VCaP cells to TRM aqueous extract. ConclusionTRM aqueous extract inhibited the proliferation of human prostate cancer VCaP cells possibly by inducing autography and down-regulating Lamin B1 expression. This study has provided a theoretical basis for the clinical application of TRM.