OBJECTIVETo compare the biological behaviors of two drug-resistant testicular cancer cell lines established by different methods.

METHODSDrug-resistance was induced in testicular cancer cell lines exposure of the cells to increasing concentrations of or a high dose of cisplatin (I-10/DDPi and I-10/DDPh cell lines, respectively). The morphological characteristics of the two cell lines were observed microscopically. The resistance index of the cells was determined with MTT assay, and the cell growth curves were drawn. The cellular expression of resistance-associated proteins MDR1 and P-gp was detected by Western blotting. The cell invasion ability was assessed with Transwell assay.

RESULTSNormal testicular cancer cell line I-10 and the two resistant cell lines all showed an adherent growth pattern. Compared with I-10 cells, I-10/DDP cells exhibited slightly heterogenous cell sizes, irregular shapes, the presence of microvilli tentacles on the cell surface, and a scattered arrangement. The cisplatin resistance index of I-10/DDPi and I-10/DDPh cells were 3.924 and 3.099, respectively. Compared with I-10, the drug-resistant cell lines showed extended doubling time with increased expressions of MDR1 and P-gp and increased cell invasiveness, which was especially obvious in I-10/DDPi cells.

CONCLUSIONBoth increasing dose exposure and high-dose exposure to cisplatin can induce cisplatin resistance in testicular cancer cells, and the resistant cells established by the latter method better mimics clinical drug-resistant tumor cells.