Proteomic detection of changes in protein expression induced by cordycepin in human hepatocellular carcinoma BEL-7402 cells.

The nucleoside analogue cordycepin (3 '-deoxyadenosine, 3 '-dA), one of the components of Cordyceps militaris, has been shown to inhibit the growth of various tumor cells. However, the probable mechanism is still obscure. In this study, the inhibition of cell growth and changes in protein expression induced by cordycepin were investigated in BEL-7402 cells. Using the MTT assay and flow cytometry, we found that cordycepin inhibits cell viability and induces apoptosis in BEL-7402 cells. Additionally, the proteins were separated using two-dimensional polyacrylamide gel electrophoresis, and eight proteins were found to be significantly affected by cordycepin compared to untreated control; among them, two were downregulated and six were upregulated. Of the eight proteins, six were identified with peptide mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) after in-gel trypsin digestion. These proteins are involved in various aspects of cellular metabolism. It is suggested that the effect of cordycepin on the growth of tumor cells is significantly related to the metabolism-associated protein expression induced by cordycepin.