Immunocytochemical Detection of hENT1 and hCNT1 in Normal Tissues, Lung Cancer Cell Lines, and NSCLC Patient Samples

Abstract Nucleoside transporters are essential for the cellular entry, efficacy, and cytotoxicity of several clinically important deoxynucleoside analogs (e.g., cytarabine and gemcitabine). We used immunohistochemistry to determine protein expression levels of the nucleoside transporters hENT1 and hCNT1 in NSCLC cell lines, NSCLC patient samples, and a variety of normal tissues. All 4 NSCLC cell lines expressed high to very high levels of both hENT1 and hCNT1. In NSCLC and normal tissues expression of hENT1 and hCNT1 ranged from completely negative to high. Immunohistochemistry might be a useful tool to predict response to deoxynucleoside analogs in malignancies treated with these drugs. Keywords: Human equilibrative nucleoside transporters (hENTs)human concentrative nucleoside transporters (hCNTs)deoxynucleoside analogsantimetabolite cytotoxic drugsimmunocytochemical staining