Troglitazone and 9cis,11trans,13trans-Conjugated Linolenic Acid: Comparison of Their Antiproliferative and Apoptosis-Inducing Effects on Different Colon Cancer Cell Lines.

Background: We have previously reported that troglitazone, a synthetic ligand for peroxisome proliferator-activated receptor γ (PPARγ), and bitter gourd seed oil rich in 9cis,11trans,13trans-conjugated linolenic acid (9c,11t,13t-CLN) prevent colon carcinogenesis. To evaluate the chemotherapeutic effect and potency of these compounds on colon cancer cells, we investigated their antiproliferative and apoptosis-inducing effects using different human colon cancer cell lines. Methods: The antiproliferative and apoptosis-inducing effects of troglitazone and 9c,11t,13t-CLN were evaluated and compared using HT-29, DLD-1 and Caco-2 cells at different stages of enterocytic differentiation. Results: Troglitazone and 9c,11t,13t-CLN decreased cell viability and induced apoptosis in three colon cancer cell lines. The susceptibility of HT-29, which expresses PPARγ at high levels, to troglitazone and 9c,11t,13t-CLN was higher than that of Caco-2 cells with low levels of PPARγ. Conclusion: Troglitazone and 9c,11t,13t-CLN exhibited more effective chemotherapeutic effects on HT-29 cells than on Caco-2 cells. Copyright © 2006 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]