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.
ABSTRACT
The eukaryotic genome is folded into higher-order conformation accompanied with constrained dynamics for coordinated genome functions. However, the molecular machinery underlying these hierarchically organized three-dimensional (3D) chromatin architecture and dynamics remains poorly understood. Here by combining imaging and sequencing, we studied the role of lamin B1 in chromatin architecture and dynamics. We found that lamin B1 depletion leads to detachment of lamina-associated domains (LADs) from the nuclear periphery accompanied with global chromatin redistribution and decompaction. Consequently, the inter-chromosomal as well as inter-compartment interactions are increased, but the structure of topologically associating domains (TADs) is not affected. Using live-cell genomic loci tracking, we further proved that depletion of lamin B1 leads to increased chromatin dynamics, owing to chromatin decompaction and redistribution toward nucleoplasm. Taken together, our data suggest that lamin B1 and chromatin interactions at the nuclear periphery promote LAD maintenance, chromatin compaction, genomic compartmentalization into chromosome territories and A/B compartments and confine chromatin dynamics, supporting their crucial roles in chromatin higher-order structure and chromatin dynamics.
Subject(s)
Humans , Chromatin , Chromosomes , Genome , Lamin Type B/geneticsABSTRACT
Lamin B1 is one of the essential members of the nuclear lamina protein family. Its main function is to maintain the integrity of nuclear skeleton, as well as to participate in the cell proliferation and aging by affecting the chromosome distribution. gene expression, and DNA damage repair. The abnormal expression of lamin B1 is related to certain diseases, including neurological diseases [e.g. neural tube defects (NDTs), adult-onset autosomal dominant leukodystrophy (ADLD)] and tumors (e.g. pancreatic cancer). It is also a potential tumor marker as well as drug target. Further research on lamin B1 will help people understand the molecular mechanism of the emergence and development of neural system diseases and tumors, and define a new future in drug target.