Unravelling the Mechanism of Cisplatin Resistance in Triple-Negative Breast Cancer: Insights from Metabolomic Profiling via Mass Spectrometry Analysis.

Triple-negative breast cancer (TNBC) poses a significant challenge due to its aggressive nature and limited treatment options, with cisplatin often used in treatment. However, the mechanism underlying the cisplatin resistance in TNBC is poorly understood. This study aimed to develop a cisplatin-resistant (cisR) TNBC cell line and understand its metabolic alterations. Characterization of cisR and cisplatin-sensitive (cisS) cell lines involved cytotoxicity, wound healing, and morphological studies. This study further employed untargeted and targeted mass spectrometry analyses for a deep metabolome comparison between cisR and cisS TNBC cell lines to elucidate the molecular mechanisms driving cisplatin resistance. Metabolomics profiling of cisR and cisS cell lines resulted in the identification of significantly altered metabolites, such as 8-acetylspermidine, d-pantothenic acid, sphingosine, sphinganine 1-phosphate (S1P), nicotinamide, choline, and certain amino acids. This global and targeted metabolomics study also revealed the downregulation of 8-acetylspermidine and d-pantothenic acid, indicating that their dysregulation is associated with cisplatin resistance in TNBC cells. Furthermore, this study unravels the dysregulation of sphingolipid metabolism, particularly the downregulation of ceramide, sphingosine, and S1P, and glycerophospholipid metabolism (choline, LysoPC) as a potential contributor to cisplatin resistance in TNBC cells. Similarly, upregulation of nicotinamide metabolism key players nicotinate and 1-methylnicotinamide emerges as a contributor to cisplatin resistance. Aminoacyl t-RNA biosynthesis and ABC transporter metabolic pathways involving proline, valine, threonine, glutamic acid, and phenylalanine amino acids are also implicated in developing TNBC-resistant cells. This comprehensive metabolomics study identifies distinct metabolic signatures and key dysregulated pathways associated with cisplatin resistance in TNBC, offering potential candidate marker and therapeutic targets.