ABSTRACT
<p><b>OBJECTIVE</b>To explore the differences in the expression of the ATP-binding cassette (ABC) transporter genes between normal nasopharyngeal tissue and nasopharyngeal carcinoma (NPC).</p><p><b>METHODS</b>Real-time quantitative PCR was used to examine the gene expression of 10 ABC transporters in both NPC and normal nasopharyngeal tissue.</p><p><b>RESULTS</b>The 10 drug resistance-associated ABC transporters were expressed at different levels in NPC. ABCA2 and ABCC3 genes were strongly expressed in both the NPC and normal nasopharyngeal tissues, and ABCC1, ABCC5 and ABCG2 gene expressions were significantly higher in NPC than in normal nasopharyngeal tissue, whereas the ABCB1, ABCC2, ABCC3, ABCC4, ABCC6 and ABCC11 genes were all expressed at low levels in both the carcinoma and normal tissues.</p><p><b>CONCLUSION</b>The transporters with high expressions in both the cancer and normal samples are correlated to the naturally occurring multidrug resistance of NPC, and those with high expression only in NPC may play an important role in drug resistance to chemotherapeuatic agents. The agents targeting the ABC transporters that are lowly expressed in both the carcinoma and normal tissues might serve as sensitivitive chemotherapeutics against NPC.</p>