The presence of certain volatile biomarkers in the breath of patients with gastric cancer has been reported by several studies; however, the origin of these compounds remains controversial. In vitro studies, involving gastric cancer cells may address this problem and aid in revealing the biochemical pathways underlying the production and metabolism of gastric cancer volatile indicators. Gas chromatography with mass spectrometric detection, coupled with headspace needle trap extraction as the pre-concentration technique, has been applied to map the volatilomic footprints of human HGC-27 and CLS-145 gastric cancer cell lines and normal Human Stomach Epithelial Cells (HSEC). In total, 27 volatile compounds are found to be associated with metabolism occurring in HGC-27, CLS-145, and HSEC. Amongst these, the headspace concentrations of 12 volatiles were found to be reduced compared to those above just the cultivating medium, namely there was an observed uptake of eight aldehydes (2-methylpropanal, 2-methyl-2-propenal, 2-methylbutanal, 3-methylbutanal, hexanal, heptanal, nonanal, and benzaldehyde), three heterocyclic compounds (2-methyl-furan, 2-ethyl-furan, and 2-pentyl-furan), and one sulfur-containing compound (dimethyl disulphide). For the other 15 volatiles, the headspace concentrations above the healthy and cancerous cells were found to be higher than those found above the cultivating medium, namely the cells were found to release three esters (ethyl acetate, ethyl propanoate, and ethyl 2-methylbutyrate), seven ketones (2-pentanone, 2-heptanone, 2-nonanone, 2-undecanone, 2-tridecanone, 2-pentadecanone, and 2-heptadecanone), three alcohols (2-methyl-1-butanol, 3-methyl-1-butanol, and 2-ethyl-1-hexanol), one aromatic compound (toluene), and one sulfur containing compound [2-methyl-5-(methylthio) furan]. In comparison to HSEC, HGC-27 cancer cell lines were found to have significantly altered metabolism, manifested by an increased production of methyl ketones containing an odd number of carbons. Amongst these species, three volatiles were found exclusively to be produced by this cell line, namely 2-undecanone, 2-tridecanone, and 2-heptadecanone. Another interesting feature of the HGC-27 footprint is the lowered level of alcohols and esters. The CLS-145 cells exhibited less pronounced changes in their volatilomic pattern compared to HSEC. Their footprint was characterized by the upregulated production of esters and 2-ethyl-hexanol and downregulated production of other alcohols. We have therefore demonstrated that it is possible to differentiate between cancerous and healthy gastric cells using biochemical volatile signatures.

多项研究报告称，胃癌患者的呼吸中存在某些挥发性生物标志物；然而，这些化合物的来源仍然存在争议。体外涉及胃癌细胞的研究可能会解决这个问题，并有助于揭示胃癌挥发性指标产生和代谢的生化途径。气相色谱与质谱检测结合顶空针捕集萃取作为预浓缩技术，已用于绘制人 HGC-27 和 CLS-145 胃癌细胞系和正常人胃上皮细胞 (HSEC) 的挥发足迹。总共发现 27 种挥发性化合物与 HGC-27、CLS-145 和 HSEC 中发生的代谢有关。其中，与仅在培养基上方相比，发现 12 种挥发物的顶空浓度有所降低，即观察到八种醛的吸收（2-甲基丙醛、2-甲基-2-丙烯醛、2-甲基丁醛、3 -甲基丁醛、己醛、庚醛、壬醛和苯甲醛）、三种杂环化合物（2-甲基呋喃、2-乙基呋喃和2-戊基呋喃）和一种含硫化合物（二甲基二硫醚）。对于其他 15 种挥发物，发现健康细胞和癌细胞上方的顶空浓度高于培养基上方的浓度，即细胞释放三种酯（乙酸乙酯、丙酸乙酯和 2-甲基丁酸乙酯） 、 七种酮（2-戊酮、2-庚酮、2-壬酮、2-十一酮、2-十三酮、2-十五酮和 2-十七酮）、三种醇（2-甲基-1-丁醇、3-甲基-1 -丁醇和2-乙基-1-己醇）、一种芳香族化合物（甲苯）和一种含硫化合物[2-甲基-5-(甲硫基)呋喃]。与 HSEC 相比，HGC-27 癌细胞系的代谢显着改变，表现为含有奇数碳的甲基酮的产生增加。在这些物种中，发现三种挥发物仅由该细胞系产生，即2-十一酮、2-十三酮和2-十七酮。HGC-27 足迹的另一个有趣特征是醇和酯的含量降低。与 HSEC 相比，CLS-145 细胞的挥发模式变化不太明显。他们的足迹的特点是酯类和2-乙基己醇的产量上调，而其他醇的产量下调。因此，我们证明可以利用生化挥发性特征来区分癌性胃细胞和健康性胃细胞。