Establishment of multidrug-resistant human colorectal cancer cell line LoVo/5-FU：a preliminary study of biological characterization

doi:10.3321/j.issn:1673-4254.2001.01.008

Abstract：Objective To investigate the changes in biological properties ofthe multidrug-resistant (MDR) variant of human colorectal cancer LoVo cell lines and to explore the mechanism for MDR generation in human colorectal cancer cells. Method A MDR variant of human colorectal cancer to 5-FU treatment, LoVo/5-FU, was established in vitro by exposing parent LoVo cells to pulse treatment with 2.5 μg/ml 5-FU over a period of 6 months. Its sensitivity to 6 antitumor agents was observed by MTT method, and morphological observation under light microscope and electron microscope of both LoVo and LoVo/5-FU cells were performed. Bcl-2 gene expressions in two cells were assayed immunohischemically. Results The LoVo/5-FU cells possessed tolerance for 5-FU 16.48 times higher than that of parent LoVo cells,and exhibited cross-resistance to mitomycin,cisplatin and adriamycin, but not to methotrexate or Ara-C. Compared with the parent cells, the LoVo/5-FU cells showed a lower growth rate and confluent density with positive findings of P-GP expression in approximately 85% of them. Bcl-2 gene expression was detected in the cytoplasm of both LoVo and LoVo/5-FU cells,but the latter had higher expression levels. Conclusion The changed biological properties of LoVo/5-FU might be related to its MDR phenotype, and the generation of MDR, which may be due to multiple mechanisms, reduces the effectiveness of chemotherapy for colorectal cancer.