[Establishment and biological characterization of 5-fluorouracil-resistant human colon cancer HT-29/5-FU cell line].

To establish 5-fluorouracil (5-FU)-resistant human colon cancer HT-29 cell line (HT-29/5-FU) in vitro and observe its biological properties.The HT-29/5-FU cell line was established by continuously exposing the HT-29 cells to ascending doses of 5-FU. The morphology and colony formation rate were detected. The growth curve and the chemosensitivity of HT-29/5-FU cell line were determined by MTT assay. Western blotting was used to analyze the expressions of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD). Cell cycle and apoptosis were measured by flow cytometry.The resistance of HT-29/5-FU cells to 5-FU was 3.59-fold greater than that of HT-29 cells. The morphology of HT-29/5-FU cells differed from that of HT-29 cells. Compared with HT-29 cells, HT-29/5-FU cells showed remarkable reduction of cell proliferation and colony formation, higher expressions of TS and DPD, higher percentage of cells in the S phase, and stronger ability of resistance to apoptosis induced by 5-FU.The biological characters of HT-29/5-FU cell line may play an important role in 5-FU-resistant mechanisms, which may also contribute to elucidate the potential mechanisms of tumor drug resistance as well as resistance reversal.