Taurine But Not Proline Protects Cells from Cisplatin, Activates p21, and Fibronectin Expression

Amino acids are macromolecules forming proteins. This makes them essential for life, as proteins are needed for many cell functions. Amino acids that are not part of a protein, but rather freely floating, are called free amino acids (FAAs). Cells can use FAAs to support metabolism, growth, and survival. We have previously determined the intracellular concentration of various FAAs in cells isolated from ovarian cancer (OC) malignant fluids. Taurine and proline were among the most enriched free intracellular amino acids in these patient cell samples. In contrast to malignant samples, a tissue culture model representing OC precursor cells contained significantly less intracellular taurine and proline. Taurine but not proline supplementation induced p21 activation, fibronectin deposition, cell adhesion, and resistance to DNA-damaging agent cisplatin. Our data suggest the possibility that accumulation of intracellular taurine but not proline can protect cells from cisplatin and this protection is associated with the activation of p21 and fibronectin protein expression.