Klostergaard J, Leroux M E, Hsu H A, Hsi B P, Siddik Z H, Danhauser L L, Tomasovi S P
Department of Tumor Biology, University of Texas, Houston, USA.
Cancer Chemother Pharmacol. 1996;37(3):235-41. doi: 10.1007/BF00688322.
Effective adjunctive therapies for colorectal carcinoma are clearly needed. We evaluated the cytotoxic responses in vitro of human colon carcinoma cell lines to combined modalities: 5-fluorouracil/leucovorin (5-FU/LV), carboplatin (CP), tumor necrosis factor (TNF) and hyperthermia (HTX). Cytotoxicity was evaluated in a cell proliferation assay using crystal violet staining. 5-FU/LV was administered 2-3 days before TNF and CP, followed 1 h later by HTX. These cell lines were relatively resistant to HTX alone (42 degrees C for 2 h), but were heterogeneous in their responses to various doses of the other single agents. This heterogeneity was also evident for combined modalities: the HCT-15 cell line exhibited significant supra-additivity for selected doses of CP, TNF and 5-FU/LV, which was further enhanced by hyperthermia. In contrast, the HT-29 cell line did not demonstrate a strong pattern for supra-additivity, whereas the DLD-1 cell line had an intermediate response. Thus, our results suggest one approach to develop effective and dose-sparing multimodality therapeutic regimens for colon adenocarcinoma.
