Biological effect of expression of exogenous human nuclear receptor hLRH-1 in SW480 cells and its molecular mechanism

Objective: To explore the possible biological function of human nuclear receptor hLRH-1 in tumorigenesis and progress of colon cancer. Methods: Plasmids pcDNA3-hLRH-1 were introduced into SW480 cells via lipofectamine. The expression of mRNA and protein of exogenous hLRH-1 were detected by RT-PCR and western blotting, respectively. MTT assay was carried out to survey the proliferation of SW480 cells with overexpression of hLRH-1. Meanwhile, the expression of proliferation-related genes cyclin E1 and cyclin D1, and apoptosis-related genes PTEN and Rb1, were analyzed by real- time RT-PCR. Results: The proliferation of SW480 cells was promoted under the condition of overexpression of hLRH-1. The expression of cyclin E1 was up-regulated significantly, while that of PTEN and Rb1 were down-regulated in SW480 cells with overexpressed hLRH-1. Conclusion: The expression of exogenous hLRH-1 in SW480 cells induced the proliferation resulting form up-regulation of cyclin E1, as well as participated in the regulation of apoptosis via influencing the expression of PTEN and Rb1.

Experimental study on siRNA expressing vector-based RNA interference targeting c-Myc in human hepatocellular carcinoma cell line BEL-7402

Objective: To explore the inhibition of the expression of c-Myc in human hepatocellular carcinoma via vector-based RNA interference (RNAi). Methods: Two RNA interference DNA templates targeting c-Myc oncogene were designed via online software and synthesized. By ligation, the fragments were inserted into pSilencer 1.0-U6 to construct the recombinant siRNA expressing plasmids. The identified recombinants were introduced into BEL-7402 cells with Lipofactamine. The inhibition of c-Myc expression, together with the expression of CDK4, hTERT and Gadd45β in c-Myc down-regulated BEL-7402 cells, were analyzed by semi-quantitative RT-PCR. Results: Two recombinant plasmids pSic-myc-1 and pSic-myc-2, which direct the yields of siRNAs targeting c-Myc in cells, were constructed. Among which, pSic-myc-2 was shown to trigger a RNAi-mediated inhibition of expression of c-Myc in BEL-7402 by up to 90%. In c-Myc knockdown BEL-7402 cells, the expression of CDK4 and hTERT were down-regulated with a ratio of 85% and 57%, respectively, while the expression of Gadd45β was up-regulated by up to 110%. Conclusion: The expression of c-Myc in BEL-7402 could be suppressed by vector-based RNA interference successfully. The knockdown of c-Myc in turn resulted in the changes of expression of genes related to cell proliferation and apoptosis. Thus, our study provided a preliminary data in searching of a c-Myc-targeted RNAi therapy of human hepatocellular carcinoma.

Dichloromethane as a methylene synthon for regioselective linkage of diverse carboxylic acids:Direct access to methylene diesters under metal-free conditions

A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters from a wide scope of carboxylic acids substrates with good functional group tolerance. Several gram-scale reactions have been performed to evaluate the effectiveness and practicality of this protocol.