RESUMO
<p><b>OBJECTIVE</b>To study the mechanism of multidrug resistance and its reversal by mdr-1 ribozyme in human ovarian cancer.</p><p><b>METHODS</b>The expression of mdr-1 and p-glycoprotein (p-gp) was studied by confocal laser microscope (Confocal), RT-PCR and Western blot analysis in adriamycin-resistant human ovarian cancer cell line (A2780/ADM) and adriamycin-sensitive one (A2780). The mdr-1 ribozyme was transfected into the A2780/ADM by Lipofectamine 2000 to overcome the multidrug resistance in ovarian cancer.</p><p><b>RESULTS</b>The expression of mdr-1 mRNA and p-gp in A2780/ADM was significantly higher than that in A2780. The expression of mdr-1 mRNA and p-gp in A2780/ADM was lowered after being transfected by mdr-1 ribozyme.</p><p><b>CONCLUSION</b>Multidrug resistance of A2780/ADM, possibly being caused by overexpression of mdr-1 gene, can be partially reversed by mdr-1 ribozyme.</p>