Quantitative analysis of phosphatidylcholines and phosphatidylethanolamines in urine of patients with breast cancer by nanoflow liquid chromatography/tandem mass spectrometry

Abstract

Phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs) from urine of patients with breast cancer were qualitatively and quantitatively analyzed by nanoflow liquid chromatography-electrospray ionization tandem mass spectrometry (nLC-ESI-MS-MS). Urinary phospholipids (PLs) were extracted from three different categories of patients (non-cancer controls and breast cancer patients before and after surgery) by first lyophilizing only 1 mL of urine sample to enrich PLs. Next, nLC-ESI-MS-MS analysis of intact urinary phospholipids was performed, resulting in structural identification of 21 PCs and 12 PEs, followed by quantitative analysis using a multiple standard addition method. This study demonstrated that nLC-ESI-MS-MS can be powerfully utilized for the study of relative changes in the contents and concentration of urinary PCs and PEs from breast cancer patients: total concentration of PCs and PEs of patient sample increased to (144 +/- 9)% and (171 +/- 11)%, respectively, compared to control sample but they decreased significantly following surgery.