['To investigate the effects of hydrocamptothecin on the expression of Wnt signaling pathway inhibitor DKK-1 in tumor cells.', 'Human HepG2, Hep3B, LoVo and U251 cells were treated with the antitumor drug Hydrocamptothecin. DKK-1 mRNA expression in the cells was detected with RT-PCR, and beta-catenin expression was measured by fluorescence-activated cell sorting (FACS).', 'DKK mRNA in Hep3B, HepG2, LoVo and U251 cells was significantly increased after hydrocamptothecin treatment for 24 h, and the percentage of beta-catenin-positive cells and fluorescence intensity for beta-catenin expression was lowered in the cells after the treatment.'] Does [ Hydrocamptothecin promote the mRNA expression of Wnt signaling inhibitor DKK-1 ]?