The investigation and development of the cancer stem cell (CSC) model has received much focus during these years. CSC is characterized as a small fraction of cancer cells that have an indefinite ability for self-renewal and pluripotency and are responsible for initiating and sustaining of the bulk of cancer.

Prostate cancer is a leading cause of cancer-related death in adult men. It can regress dramatically upon antihormonal therapy, but it often recurs in a more aggressive, androgen-independent form. Defining the prostate tissue stem cells (PrSCs) and their involvement in cancer initiation and maintenance may lead to better therapeutics. Using a tissue-regeneration model in which dissociated prostate epithelial cells mixed with inductive mesenchyme give rise to prostatic tubules, we have identified a small population of prostate cells that contains multiple stem cell characteristics. In this system, prostate cancer can be initiated by autocrine or paracrine growth factor signaling and intracellular overexpression of genes often found mutated in human prostate cancer. Using an in vitro prostate sphere assay, we further defined the PrSC population and demonstrated their selfrenewal and multilineage differentiation capabilities. Microarray analyses of the stem-and non-stem-cell populations have assisted us in finding and evaluating additional markers that can better define the PrSC population and further delineate the different cell types of the prostate, including those that serve as the target cell for tumor initiation.

In the present study, the effect of exopolysaccharides (EPSs) extracted from Pseudomonas tolaasii on the growth of Pleurotus ostreatus mycelia was determined. P. ostreatus mycelia was cultivated with different concentrations of P. tolaasii EPSs, and their mycelial growth rate, protein content, and enzyme activity were measured and compared. The results showed that EPSs inhibited the growth of P. ostreatus. The proline and vitamin C contents of P. ostreatus increased at an EPS concentration of 40%. The cellulase, α-amylase, protein, and glucose utilisation rates of P. ostreatus gradually decreased with the increase in EPS concentration. Altogether, P. tolaasii EPSs had a significant inhibitory effect on mycelial growth. Therefore, we concluded that in addition to tolaasin, EPSs may also be the virulence factors responsible for the pathogenesis of P. tolaasii.

Resveratrol is identified as a natural cancer chemoprevention agent. There has been a lot of interest in designing and developing resveratrol analogs with cancer chemoprevention activity superior to that of parent molecule and exploring their action mechanism in the past several decades. In this study, we have synthesized resveratrol analogs of compounds A-C via conjugated chain elongation based on isoprene unit retention strategy. Remarkably, cytotoxic activity analysis results indicated that compound B possesses the best proliferation inhibition activity for NCI-H460 cells in all the test compounds. Intriguingly, compound B displayed a higher cytotoxicity against human non-small cell lung cancer cells (NCI-H460) compared to normal human embryonic lung fibroblasts (MRC-5). Afterward, flow cytometry analysis showed that compound B would induce cell apoptosis. We further researched the action mechanism. When NCI-H460 cells were incubated by compound B for 6 or 9 h, respectively, the intracellular reactive oxygen species (ROS) level was enhanced obviously. With elevation of intracellular ROS level, flow cytometry measurement verified mitochondrial transmembrane potential collapse, which was accompanied by the up-regulation of Bax and down-regulation of Bcl-2. More interestingly, compound B increased the expression of caspase-9 and caspase-3, which induced cell apoptosis. Moreover, compound B arrested cell cycle in G0/G1 phase. These are all to provide useful information for designing resveratrol-based chemoprevention agent and understanding the action mechanism.