RESUMO
<p><b>OBJECTIVE</b>To investigate the influence of Lewis y antigen on the gene expression of partial drug resistance associated proteins in human ovarian cancer cell line RMG-I-H.</p><p><b>METHODS</b>RT-PCR was used to determine the gene expressions of partial drug resistance associated proteins in RMG-I-H cell line transfected with alpha1, 2-fucosyltransferases gene and RMG-I cell line, as well as in RMG-I-H treated with or without anti-Lewis y monoclonal antibody at the concentration of 10 micro/g/ml. The immunocytochemical method was used to detect the expression of P-glycoprotein (P-gp) in RMG-I and RMG-I-H cell lines. RMG-I and RMG-I-H cells were transplanted into nude mice and the expression of P-gp in the tissues was measured by immunohistochemistry.</p><p><b>RESULTS</b>The mRNA expressions of protein kinase C-alpha (PKC-alpha), topoismerase I ( Topo I ), multidrug resistance-associated protein-1 (MRP-1), and MRP-2 were significantly higher in RMG-I-H cells than those in RMG-I cells (0.46 +/- 0.02 vs. 0.27 +/- 0.05, 0.82 +/- 0.08 vs. 0.52 +/- 0.04, 0.66 +/- 0.07 vs. 0.34 +/- 0.12, and 0.44 +/- 0.08 vs. 0.23 +/- 0.05; all P < 0.05). However, the mRNA expression of multi-drug resistance 1 (MDR-1) was significantly lower in RMG-I-H cells than that in RMG-I cells (0.26 +/- 0.05 vs. 0.45 +/- 0.08, P < 0.05). The P-gp level increased in RMG-I-H cells compared with that in RMG-I cells both in vivo and in vitro (P < 0.05). Expressions of MDR-1, MRP-1, MRP-2, PKC-alpha, and Topo I mRNA decreased by the time in RMG-I-H cells treated with anti-Lewis y monoclonal antibody (all P < 0.05), while mRNA expressions of those genes in the control group did not statistically change (P > 0.05). In addition, MDR-1, MRP-1, MRP-2, PKC-alpha, and Topo I mRNA expressions were significantly lower in RMG-I-H cells treated with anti-Lewis y monoclonal antibody than those in the control group at 6 hours (all P < 0.05) and the inhibition ratios were 48.55%, 77.50%, 70.18%, 45.86%, and 46.13%, respectively.</p><p><b>CONCLUSION</b>The Lewis y antigen of the human ovarian cancer cell surface is closely correlated with the regulation on the gene expression of partial drug resistance associated proteins.</p>