TY - JOUR T1 - Determinants of Cisplatin and Irinotecan Activities in Human Lung Adenocarcinoma Cells: Evidence of Cisplatin Accumulation and Topoisomerase I Activity JF - In Vivo JO - In Vivo SP - 717 LP - 721 VL - 19 IS - 4 AU - TADASHI MATSUMURA AU - NAGIO TAKIGAWA AU - KATSUYUKI KIURA AU - TAKUO SHIBAYAMA AU - MASAKAZU CHIKAMORI AU - MASAHIRO TABATA AU - HIROSHI UEOKA AU - MITSUNE TANIMOTO Y1 - 2005/07/01 UR - http://iv.iiarjournals.org/content/19/4/717.abstract N2 - To elucidate the sensitivity of adenocarcinoma of the lung to cisplatin and irinotecan, intracellular glutathione (GSH) and glutathione S-transferase (GST)-π concentrations and topoisomerase (topo) I activity were investigated using six adenocarcinoma cell lines. The antiproliferative activity was determined by MTT assay in terms of inhibition concentration (IC50) values. The IC50 values to cisplatin were not correlated with the amounts of intracellular GSH or GST-π, but with intracellular accumulation of platinum (r=-0.91, p=0.013). IC50 values to SN-38 were correlated with topo I activity determined by relaxation assay of pBR322 (r=-0.83, p=0.040). These results suggest that platinum accumulation and topo I activity have definite impacts on the sensitivity of lung adenocarcinoma to cisplatin and irinotecan, respectively. Copyright © 2005 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved ER -