The decrease of cell membrane fluidity by the non-steroidal anti-inflammatory drug Licofelone inhibits epidermal growth factor receptor signalling and triggers apoptosis in HCA-7 colon cancer cells

Abstract

The ability to induce changes in cell membrane properties is nowadays considered an additional mechanism to explain the pharmacological effects of non-steroidal anti-inflammatory drugs (NSAIDs). We previously demonstrated that the NSAID Licofelone, a dual cyclooxygenase/5-lipoxygenase inhibitor, triggers apoptosis in HCA-7 colon cancer cells independently from the inhibition of these enzymes. Here, we provide evidence that, in HCA-7 cells, the pro-apoptotic effect of this drug relies, at least in part, on its ability to inhibit epidermal growth factor receptor (EGFR) signalling by a decrease of cell membrane fluidity. Indeed, Licofelone induced a relevant change in the relative proportions of some saturated, monounsaturated and polyunsaturated fatty acids constituting HCA-7 phospholipid fraction and significantly increased the levels of cholesterol in HCA-7 cell membrane. All of these changes resulted in a remarkable decrease of membrane fluidity. Such phenomenon was associated with the block of EGFR kinase activity and of its downstream targets, the p44-42 mitogen-activated protein kinase (MAPK) and AKT cascades, whose inhibitions were found to induce apoptosis in HCA-7 cells. Overall, these findings provide a new additional mechanism by which NSAIDs are effective toward colon cancer cells.