Table 3.

Proteomics for colorectal precancer detection

Technology	Details	Indicators in colorectal diseases	Refs.
liquid chromatography-tandem mass spectrometry (LC-MS/MS)	Triple Quadrupole: Targeted quantification (such as biomarker validation).	TFR1, SAHH, and HV307 may be considered as potential biomarkers for CRC screening.	[34, 67]
	Quadrupole Time of Flight: Non targeted screening, metabolite identification.
	Orbitrap: Deep proteomics and post-translational modification analysis.
	Ion Trap: Small molecule structure analysis and multi-level fragmentation research.
Metaproteomics	Proteins were digested into peptides and analyzed with an Orbitrap LC-MS/MS, while MetaProteomeAnalyzer software identified proteins and interpreted taxonomic and functional data.	The metaproteins gamma-glutamyl hydrolase, resistin 50 olfactomedin-4 and trefoil factor 252 as well as the metaproteins of the complement system C4-A, and plasma protease C1 inhibitor may be correlated with IBD.	[60]
Tandem Mass Tag (TMT)/Isobaric tags for relative and absolute quantification (iTRAQ)	Labelling with isotope tags, followed by enzymatic digestion of amino acid N-terminals and lysine residues, specific labelling with TMT/iTRAQ reagents, and finally tandem mass spectrometry analysis, allowing simultaneous comparison of the relative amounts of protein.	β-catenin, DCN, septin-7, and S100A10 are the differentially expressed proteins involved in the development of CRC. RRP12 and SERPINH1 may play an important role in the N-A and A-C processes. Potential clinical application of UTP18 in predicting colorectal adenoma recurrence.	[21, 22, 58]
Matrix-assisted laser desorption/ionization-time of flight mass spectrometry(MALDI-TOF/TOF MS)	In MALDI-TOF MS, a laser bombards the sample-matrix film, causing the matrix to absorb energy and ionize biomolecules via proton transfer. These ions are accelerated through a flight tube by an electric field, and their time of arrival at the detector determines their mass-to-charge ratio (m/z) and signal value, forming corresponding peaks.	eIF5A-1, S100P, ANXA3, S100A11 and FABPL may play a crucial role in early CRC development.	[10]
Olink Target 96-plex panels	Olink Target 96 technology uses a pair of antibodies, each linked to a specific DNA strand, to detect proteins. When both antibodies bind to a protein, their DNA strands complement and form a double-stranded DNA template via enzyme extension, allowing protein quantification through Proximity extension assay (PEA).	WISP-1, ESM-1, and TFPI-2 are closely associated with the occurrence of colorectal cancer.	[14]