Release of volatile organic compounds (VOCs) from colorectal cancer cell line LS174T.

Colorectal cancer (CRC) is the third most common cancer worldwide. To date, no non-invasive and specific biomarkers have been identified for the diagnosis of CRC. The analysis of volatile organic compounds (VOCs) is attracting increasing attention and provides the possibility of a non-invasive diagnosis. Solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) have been used to analyze the VOCs released from the headspace gas of LS174T (Dukes' type B colorectal adenocarcinoma) cells, arsenic trioxide (ATO)-treated LS174T cells and the blood from tumor-bearing mice. The data were processed using principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA), which showed that the levels of decanal, 2,4-dimethyl- heptane, and twelve other metabolites were significantly greater in the headspace gas of the LS174T cells and blood of tumor-bearing mice. Additionally, in vivo experiments indicated that formic acid, ethenyl ester and p-trimethylsilyloxyphenyl-(trimethylsilyloxy)trimethylsilylacrylate were consumed during tumor growth. In conclusion, VOCs such as 1-methoxy-hexane and 2,4-dimethyl-heptane could be useful diagnostic markers for CRC. Further research should focus on the potential metabolic pathways associated with these profiles.