Simultaneous LC-MS/MS-Based Quantification of Free 3-Nitro-l-tyrosine, 3-Chloro-l-tyrosine, and 3-Bromo-l-tyrosine in Plasma of Colorectal Cancer Patients during Early Postoperative Period

Abstract

Quantification with satisfactory specificity and sensitivity of free 3-Nitro-l-tyrosine (3-NT), 3-Chloro-l-tyrosine (3-CT), and 3-Bromo-l-tyrosine (3-BT) in biological samples as potential inflammation, oxidative stress, and cancer biomarkers is analytically challenging. We aimed at developing a liquid chromatography–tandem mass spectrometry (LC-MS/MS)-based method for their simultaneous analysis without an extract purification step by solid-phase extraction. Validation of the developed method yielded the following limits of detection (LOD) and quantification (LOQ) for 3-NT, 3-BT, and 3-CT: 0.030, 0.026, 0.030 ng/mL (LODs) and 0.100, 0.096, 0.098 ng/mL (LOQs). Coefficients of variation for all metabolites and tested concentrations were <10% and accuracy was within 95–105%. Method applicability was tested on colorectal cancer patients during the perioperative period. All metabolites were significantly higher in cancer patients than healthy controls. The 3-NT was significantly lower in advanced cancer and 3-BT showed a similar tendency. Dynamics of 3-BT in the early postoperative period were affected by type of surgery and presence of surgical site infections. In conclusion, a sensitive and specific LC-MS/MS method for simultaneous quantification of free 3-NT, 3-BT, and 3-CT in human plasma has been developed.

Sitagliptin Modulates Oxidative, Nitrative and Halogenative Stress and Inflammatory Response in Rat Model of Hepatic Ischemia-Reperfusion

“…Free CT, BT and NT were measured on the basis of the previously developed method [ 35 ]. Briefly, 100-microliter aliquots of homogenates or calibration standards with 20 µL of 0.2% TFA and 10 µL of internal standard (isotope labeled analogs of CT, BT and NT) were mixed for one minute.…”

Recent progress in the LC–MS/MS analysis of oxidative stress biomarkers

“…In the meantime, a fast and reliable LC–MS/MS method, using a simple mixed‐mode SPE approach, was developed and validated to quantify 3‐NT in human plasma [208]. Recently, another LC–MS/MS method was developed for the simultaneous determination of 3‐NT, 3‐chlorotyrosine, and 3‐bromotyrosine in plasma of colorectal cancer patients, using protein precipitation as a sample preparation technique [209].…”

Facile and Compact Electrochemical Paper-Based Analytical Device for Point-of-Care Diagnostic of Dual Carcinogen Oxidative Stress Biomarkers through a Molecularly Imprinted Polymer Coated on Graphene Quantum-Dot Capped Gold

“…3-Nitrotyrosine (3-NT) is widely used as a marker for inflammation-derived reactive nitrogen species. It is the final product of tyrosine (Tyr) nitration and represents protein modification depending on nitric oxide ( • NO). , A significant increase in 3-NT levels is associated with various diseases such as atherosclerosis, rheumatoid arthritis, Alzheimer’s disease, cardiovascular diseases, and cancer. − In addition, 4-nitroquinoline N-oxide (4-NQO) is widely recognized as a biomarker in the study of DNA damage and repair and in generating mutants for genetic screens. − Thus, 4-NQO is a critical biomarker of oxidative stress produced by cancer tumorigenic cells. − An increase in oxidative stress in the human body generates high 4-NQO levels that may cause a highly carcinogenetic effect, such as mutagenicity and genotoxicity, and leads to various types of disorders such as cancer, neurodegeneration, and lung diseases. , The levels of 3-NT and 4-NQO in body fluids represent a carcinogenic oxidative stress indicator and directly index human body health. Hence, an early and quick diagnosis is needed, as it may help improve patient survival and reduce treatment costs.…”