Identification of a Lung Cancer Biomarker Using a Cancer Cell Line and Screening of Olfactory Receptors for Biomarker Detection

Several studies investigated the development of a non-invasive and early diagnostic method for cancer. Recently, the volatile organic compounds (VOCs) exhaled from cancer patients have been shown to act as a potential biomarker for cancer. However, the gas profile of breath is highly variable and not conducive to identification of biomarkers accurately. Accordingly, we identified a cancer-specific VOC as a biomarker using an in vitro cancer system in order to exclude the variables from patient condition. VOCs were collected from the headspace gas of lung cancer cell line (SK-MES) and normal lung cell line (MRC-5), followed by analysis using solid-phase microextraction (SPME)-GC/MS. As a result, 2-ethyl-1-hexanol was detected from headspace gas of SK-MES and decided as a potential biomarker for lung cancer. By screening human olfactory receptor libraries to detect a lung cancer biomarker, human olfactory receptor 4D11P (hOR4D11P) was identified as a receptor specific for 2-ethyl-1-hexanol and expressed heterologously in HEK293 cells. Additionally, we generated nanovesicles containing hOR4D11P from HEK293 cells and confirmed the expression and functionality of hOR4D11P in nanovesicles.

Automated summary

This study identified a potential lung cancer biomarker, 2-ethyl-1-hexanol, through an in vitro cancer system; additionally, the olfactory receptor 4D11P was identified as the receptor for this specific marker through screening human olfactory receptor libraries and expressed heterologously in nanovesicles.