RT Journal Article SR Electronic 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 FD International Institute of Anticancer Research SP 717 OP 721 VO 19 IS 4 A1 TADASHI MATSUMURA A1 NAGIO TAKIGAWA A1 KATSUYUKI KIURA A1 TAKUO SHIBAYAMA A1 MASAKAZU CHIKAMORI A1 MASAHIRO TABATA A1 HIROSHI UEOKA A1 MITSUNE TANIMOTO YR 2005 UL http://iv.iiarjournals.org/content/19/4/717.abstract AB 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