RESUMO
<p><b>OBJECTIVE</b>To investigate the biology characters of CD133+ cancer stem cells from Hep-2 cell line.</p><p><b>METHODS</b>The Flow cytometry was applied to purify CD133+ cells from Hep-2 cell line. The sorted CD133+ cells were cultured in RPMI1640. The ability of migration, invasion and clonality of CD133+ cells were performed to characterize the properties of the cells. CD133+ cells and CD133- control cells were treated with paclitaxel and exposed respectively to X-rays emitted by linear accelerator with a dose of 10 Gy. The surviving rates and growth inhibition ratio of cells in two groups were detected with MTT assay to observe the resistance to irradiation and chemotherapy in CD133+ cells.</p><p><b>RESULTS</b>The percentage of CD133+ cells in the unsorted and the sorted cells were 3.1% +/- 0.2% and 90.2% +/- 5.5%, respectively. CD133+ cells showed the higher proliferation and colony ability than CD133- cells. The numbers of CD133+ and CD133- cells that passed the membrane of Transwell chamber were 526 +/- 39 and 220 +/- 20 respectively (t = 22.08, P < 0.001). The colony forming units of three passages were 30.0% +/- 4.7%, 32.2% + 3.6%, 32.7% + 3.4% in CD133 cells and 15.2% +/- 2.2%, 12.0% + 2.5%, 13.8% +/- 3.3% in CD133- cells. There were statistic difference between two groups (t = 8.99, t = 14.66, t = 12.69, P < 0.01). At 24, 48, and 72 hours of treatment with paclitaxel, the cell surviving rates of CD133+ cells were 90.1% +/- 5.9%, 85.1% +/- 7.1% and 70.3% +/- 6.4% and lower than those of CD133- cells, respectively (t = 5.24, t = 8.18, t = 8.14, P < 0.01) . After radiotherapy, growth inhibition ratio of CD133+ and CD133- cells were 30.0% +/- 7.1% and 55.0% +/- 6.3% (t = 8.30, P < 0.01).</p><p><b>CONCLUSIONS</b>CD133+ cells exist in a small proportion in Hep-2 cell line and they show the properties of cancer stem cells, with the resistance to irradiation and chemotherapy.</p>