A major challenge for oncologists and pharmacologists is to develop more potent and less toxic drugs that will decrease the
tumor growth and improve the survival of
lung cancer patients.
Salinomycin is a polyether
antibiotic used to kill gram-positive bacteria including mycobacteria, protozoans such as plasmodium falciparum, and the parasites responsible for the
poultry disease coccidiosis. This old agent is now a serious anti-
cancer drug candidate that selectively inhibits the growth of cancer stem cells. We investigated the impact of
salinomycin on survival, colony growth, migration and invasion of the differentiated human
non-small cell lung cancer lines LNM35 and A549.
Salinomycin caused concentration- and time-dependent reduction in viability of LNM35 and A549 cells through a
caspase 3/7-associated cell death pathway. Similarly,
salinomycin (2.5-5 µM for 7 days) significantly decreased the growth of LNM35 and A549 colonies in soft
agar.
Metastasis is the main cause of death related to
lung cancer. In this context,
salinomycin induced a time- and concentration-dependent inhibition of cell migration and invasion. We also demonstrated for the first time that
salinomycin induced a marked increase in the expression of the
pro-apoptotic protein NAG-1 leading to the inhibition of
lung cancer cell invasion but not cell survival. These findings identify
salinomycin as a promising novel therapeutic agent for
lung cancer.