Liquid chromatography-mass spectrometry-based method of TGFβ1 synergistic abundance response to fibrosis induction during in situ bladder cancer progression

Abstract In this study, we developed a high-performance liquid chromatography-tandem mass spectrometry (HPLC–MS/MS)-based method for quantitatively tracking the dynamic abundance of TGFβ1, a fibrosis marker, in tumours of mice with bladder cancer in situ. Initially, we screened the amino acid sequence of the characteristic peptide of TGFβ1 (VEQLSNMIVR) in mouse tumours by utilising the sub-ions and retention time of the Orbitrap mass spectrometer and established a standard curve by externally labelling the characteristic peptide at gradient concentrations. Subsequently, real-time feedback on the increasing trend of TGFβ1 was provided in terms of the concentration of the characteristic peptide. The results demonstrated that the quantitative method based on feature peptides had high identification specificity and excellent stability, and the relative standard deviation of the accuracy was less than 3%. Meanwhile, in combination with the established method we found that the growth rate of the relative content of TGFβ1 increased significantly when the tumour invasion extended to the lamina propria. This work provides a new feasible solution for real-time tracking and precise monitoring of small molecular proteins in pathologically complex stroma.