Copper catalysed protoboration of allenyl-Bdans: efficient synthesis of ß-boryl allyl-Bdans.

An efficient Cu-catalysed protoboration of allenyl-Bdans is presented. Under the optimized reaction conditions, a series of allenyl-Bdans reacted smoothly with B2Pin2 to afford ß-boryl allyl-Bdans in moderate to high yields with excellent regio- and stereoselectivity.

Synergistic Pd/Cu-catalysed regio- and stereoselective borylation of allenylic carbonates.

A simple Pd/Cu-catalyzed borylation of allenylic carbonates with B2Pin2 was developed using a cheap P(OEt)3 ligand. Under mild neutral conditions, 2-boryl 1,3-butadienes were obtained selectively in moderate to high yields. Furthermore, the use of different diboron reagents was also feasible in the reaction.

DDX5 promotes gastric cancer cell proliferation in vitro and in vivo through mTOR signaling pathway.

DEAD (Asp-Glu-Ala-Asp) box helicase 5 (DDX5) is an ATP-dependent RNA helicase that is overexpressed in various malignancies. Increasing evidence suggests that DDX5 participates in carcinogenesis and cancer progression via promoting cell proliferation and metastasis. However, the functional role of DDX5 in gastric cancer is largely unknown. In this study, we observed that DDX5 was significantly up-regulated in gastric cancer tissues compared with the paired adjacent normal tissues. The expression of DDX5 correlated strongly with Ki67 index and pathological stage of gastric cancer. In vitro and in vivo studies suggested that knockdown of DDX5 inhibited gastric cancer cell proliferation, colony formation and xenografts growth, whereas ectopic expression of DDX5 promoted these cellular functions. Mechanically, DDX5 induced gastric cancer cell growth by activating mTOR/S6K1. Treatment of everolimus, the specific mTOR inhibitor, significantly attenuated DDX5-mediated cell proliferation. Interestingly, the expression of DDX5 and p-mTOR in gastric cancer tissues demonstrated a positive correlation. Taken together, these results revealed a novel role of DDX5 in gastric cancer cell proliferation via the mTOR pathway. Therefore, DDX5 may serve as a therapeutic target in gastric cancer.

[Construction and expression of eukaryotic expression plasmid pcDNA3.1-smac].

AIM: To construct the eukaryotic expression vector of human gene Smac pcDNA3.1-Smac and express it in the lung adenocarcinoma A549 cells. METHODS: The Smac was amplified from human testis tissue by reverse transcriptase polymerase chain reaction (RT-PCR). Then recombined eukaryotic expression vector pcDNA3.1-Smac was constructed. After the reconbinant plasmid was proved to be constructed correctly by endonucleases digesting and DNA sequencing, we trasfected it into lung adenocarcinama cells A549 through liposome inducing. The expression of Smac in transfectant A549 was detected by RT-PCR and Western blot. And the cell growth inhibition ratio after trasfection was detected by MTT. RESULTS: The amplified fragment by PCR was coincident with the anticipated result, and its sequence was in concordance with that published on GenBank.Therefore, the gene Smac was cloned successfully, and the recombinant plasmid pcDNA3.1-Smac was also constructed successfully. Both on the mRNA level and the protein level, the expression of Smac gene was increased obviously in the transfected A549 detected by RT-PCR and Western blot respectively. The cell growth inhibition ratio in the group transfected pcDNA3.1-Smac was significantly higher compared with the pcDNA3.1 group after 72 hours. CONCLUSION: The recombinant eukaryotic expression vector pcDNA3.1-Smac was constructed, and it could be obviously expressed in lung adenocarcinoma cells A549. It is also proven that Smac has the function of growth inhibition.