MicroRNA-149 sensitizes colorectal cancer to radiotherapy by downregulating human epididymis protein 4.

Human epididymis protein 4 (HE4) was significantly up-regulated in colorectal cancer (CRC), while the potential relevance to radiation resistance of this phenomenon is still elusive. Relative expressions of target genes were quantified by real-time PCR. The protein level was determined by Western blot. The regulatory effect of miR-149 on WFDC2 (gene encoding HE4 protein) expression was analyzed by luciferase reporter assay. The response to radiation was evaluated by clonogenic assay in vitro and xenograft growth in vivo. WFDC2 was aberrantly up-regulated and miR-149 was down-regulated in CRC. MiR-149 repressed WFDC2 expression via directly targeting its 3'UTR region. The ectopic expression of miR-149 significantly sensitized CRC to radiation both in vitro and in vivo. Likewise, we further demonstrated that WFDC2-deficiency remarkably improved the radiation resistance in CRC. Simultaneously, WFDC2 rescue completely abolished the radiation sensitivity imposed by miR-149. Our data suggested that miR-149 sensitized CRC to radiation via directly inhibiting WFDC2/HE4, which would hold great promise for future therapeutic exploitations.

Triterpenes and steroids from the roots of Scorzonera austriaca.

A new D:B-friedoolean-type triterpene, 3ß-acetoxyglutin-5(10)-en-6-oxo (1), together with seventeen known compounds (2-18) was isolated from the roots of Scorzonera austriaca. Their structures were elucidated mainly by NMR and HR-ESI-MS, as well as on comparison with the reported data. Cytotoxicities of compounds 2, 4, 6, 10-14 and 16 against selected cancer cells of human promyelocytic leukemia (HL-60) and human hepatoma (BEL-7404) were measured in vitro.

Heavy metal pollution in tidal zones of Bohai Bay using the dated sediment cores.

Three sediment cores were collected in November 2003 from Dagu estuary to Qikou estuary. The main polluted heavy metals in the sediment of tidal zones for the Bohai Bay have been found by analyzing the relationship among the contents of heavy metals, the contents of geochemical elements (Fe, Al and Mn) and the size of grain. The dominating contaminative elements in tidal sediments of Bohai Bay are Pb, Zn and Cd. Their contents are higher than the corresponding upper limit of environmental background values and they have very faint correlation with the corresponding contents of geochemical elements and the size of grain, indicating the anthropogenic enrichment. Especially, the preliminary study on the pollution sources and the history of heavy metals in the Dagu estuary has been done using the dated results. The contamination by Zn and Cd also started in the middle 1950s, while the contamination by Pb appeared in the early 1940s. The pollution by Zn and Cd mainly originate from sewage discharge, while the pollution by Pb has many sources, like atmosphere deposition and industrial discharge.