Cancers have a high mortality rate due to lack of suitable specific early diagnosis tumor biomarkers. Emerging evidence is accumulating that lncRNAs (long noncoding RNAs) are involved in tumorigenesis, tumor cells proliferation, invasion, migration, apoptosis, and angiogenesis. Furthermore, extracellular lncRNAs can circulate in body fluids; they can be detected and strongly resist RNases. Many researchers have found that lncRNAs could be good candidates for tumor biomarkers and possessed high specificity, high sensitivity, and noninvasive characteristics. In this review, we summarize the detection methods and possible sources of circulating lncRNAs and outline the biological functions and expression level of the most significant lncRNAs in tissues, cell lines, and body fluids (whole blood, plasma, urine, gastric juice, and saliva) of different kinds of tumors. We evaluate the diagnostic performance of lncRNAs as tumor biomarkers. However, the biological functions and the mechanisms of circulating lncRNAs secretion have not been fully understood. The uniform normalization protocol of sample collection, lncRNAs extraction, endogenous control selection, quality assessment, and quantitative data analysis has not been established. Therefore, we put forward some recommendations that might be investigated in the future if we want to adopt lncRNAs in clinical practice.

No abstract

The occurrence of highly pathogenic avian influenza virus H5N1 highlights the urgent need for new classes of antiviral drugs. Inhibition of H5N1 entry into cells may be an effective strategy. We report the first three small molecule inhibitors saponins with 3-O-beta-chacotriosyl residue, which showed potent inhibitory activity with IC(50) of 7.22-9.25 microM. The subsequent SAR studies showed the 3-O-beta-chacotriosyl residue was essential for the activity, and the aglycone structure also affected the activity.

No abstract