Multiple effects of antitumor alkyl-lysophospholipid analogs on the cytosolic free Ca2+ concentration in a normal and a breast cancer cell line.

Synthetic alkyl-lysophospholipids (ALP) are a new class of antitumor agents which interact with the cell membrane and the intracellular signal transduction at several sites. We studied the modulation of the intracellular calcium concentration ([Ca ++ ] i ) induced by two alkylglycerophosphocholines as well as hexadecylphosphocholine and hexadecylphophoserine in a nontumorigenic and in a tumorigenic breast cell line. We found three distinct [Ca ++ ] i -modulating effects: a transient increase, a decrease and a sustained increase