A Powerful Strategy for Synthesizing Block Copolymers via Bimetallic Synergistic Catalysis.

Block copolymers, comprising polyether and polyolefin segments, are an important and promising category of functional materials. However, the lack of efficient strategies for the construction of polyether-b-polyolefin block copolymers have hindered the development of these materials. Herein, we propose a simple and efficient method to obtain various block copolymers through the copolymerization of epoxides and acrylates via bimetallic synergistic catalysis. The copolymerization of epoxides and acrylates proceeds in a sequence-controlled manner, where the epoxides-involved homo- or copolymerization occurs first, followed by the homopolymerization of acrylates initiated by the alkoxide species from the propagating polymer chain, thus yielding copolymers with a block structure. Notably, the high monomer compatibility of this powerful strategy provides a platform for synthesizing various polyacrylate-based block copolymers comprising polyether, polycarbonate, polythiocarbonate, polyester, and polyurethane segments, respectively.

5-ARI induces autophagy of prostate epithelial cells through suppressing IGF-1 expression in prostate fibroblasts.

OBJECTIVES: 5α-reductase inhibitor (5-ARI) is a commonly used medicine in the treatment of lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH). Our study mainly focuses on the mechanism of BPH development after 5ARI treatment. MATERIALS AND METHODS: Prostate specimens from patients were collected. Insulin-like growth factor 1 (IGF-1), Beclin-1, LC3 levels, was analysed by immunohistochemistry. The role IGF-1 on autophagic flux in prostate epithelial cells was studied. Additionally, effect of autophagy on recombinant grafts consisting of prostate stromal and epithelial cells in nude mice was investigated. RESULTS: We demonstrated that IGF-1 expression is down-regulated in prostate fibroblasts after long-term 5-ARI application. A decrease in IGF-1 levels was found to activate autophagic flux through the mTOR pathway in prostate epithelial cells, while the inhibition of IGF-1 receptor function induced autophagy in prostate epithelial cells. In addition, we revealed that blocking autophagic flux initiation can reduce the volume of recombinant grafts in vivo. Finally, our findings suggest that long-term 5-ARI application reduces IGF-1 secretion by prostatic stromal cells, thereby inducing autophagy of prostatic epithelial cells, which is one of the mechanisms underlying BPH pathogenesis and progression. CONCLUSIONS: Focusing on the autophagy induced by low levels of IGF-1 in prostatic epithelial cells, after elucidating AR signalling impairment of prostate stromal cells, might provide a novel strategy for the treatment and prevention of BPH development.

Regulation effect of adipose-derived mesenchymal stem cells on pancreatic cancer cells / 中华外科杂志

<p><b>OBJECTIVE</b>To analyze the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer (PaCa) cells and the the possible mechanism involved.</p><p><b>METHODS</b>ADSCs were isolated and co-cultured with PaCa cells. CCK-8 assay was used to detect the proliferation of PaCa cells. An ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. The proliferation of PaCa cells by SDF-1 was measured. AMD3100 regulated the co-culture of ADSCs and PaCa. The tumor growth of PaCa cells was assessed after treatment by ADSCs in vivo.</p><p><b>RESULTS</b>ADSCs can promote the proliferation and invasion of PaCa cells (proliferation: SW1990: 1.535 ± 0.153; PANC-1: 1.370 ± 0.100; the value of control was 1; invasion: SW1990: 47.0 ± 2.6 vs. 28.3 ± 1.3; PANC-1: 40.3 ± 1.8 vs. 24.3 ± 1.3; t = 4.332-9.558, P < 0.05). The expression of SDF-1 was high in ADSCs, but not in PaCa cells (69 ± 5 vs. 0 and 0, F = 389.134, P < 0.01). The promotion of SDF-1 on PaCa cells depends on the concentration. AMD3100 significantly downregulates these growth-promoting effects of ADSCs on PaCa cells. ADSCs significantly promoted the growth of SW1990 in nude mice at the 5(th) week (volume: (1295 ± 102) mm(3) vs. (967 ± 81) mm(3), t = 5.614, P < 0.05) , but not in PANC-1 cell.</p><p><b>CONCLUSION</b>ADSCs can promote the proliferation and invasion of PaCa cells, which may involve the SDF-1/CXCR4 axis.</p>