Ex vivoemission of volatile organic compounds from gastric cancer and non-cancerous tissue

Abstract

The presence of certain volatile organic compounds (VOCs) in the breath of patients with gastric cancer has been reported by a number of research groups; however, the source of these compounds remains controversial. Comparison of VOCs emitted from gastric cancer tissue to those emitted from non-cancerous tissue would help in understanding which of the VOCs are associated with gastric cancer and provide a deeper knowledge on their generation. Gas chromatography with mass spectrometric detection (GC-MS) coupled with head-space needle trap extraction (HS-NTE) as the pre-concentration technique, was used to identify and quantify VOCs released by gastric cancer and non-cancerous tissue samples collected from 41 patients during surgery. Excluding contaminants, a total of 32 VOCs were liberated by the tissue samples. The emission of four of them (carbon disulfide, pyridine, 3-methyl-2-butanone and 2-pentanone) was significantly higher from cancer tissue, whereas three compounds (isoprene, γ-butyrolactone and dimethyl sulfide) were in greater concentration from the non-cancerous tissues (Wilcoxon signed-rank test, p < 0.05). Furthermore, the levels of three VOCs (2-methyl-1-propene, 2-propenenitrile and pyrrole) were correlated with the occurrence of H. pylori; and four compounds (acetonitrile, pyridine, toluene and 3-methylpyridine) were associated with tobacco smoking. Ex vivo analysis of VOCs emitted by human tissue samples provides a unique opportunity to identify chemical patterns associated with a cancerous state and can be considered as a complementary source of information on volatile biomarkers found in breath, blood or urine.

Elucidation of Biochemical Pathways Underlying VOCs Production in A549 Cells

“…Nonetheless, despite the large surface for capturing VOCs, monotrap has been used solely for static sampling. This means that improving the preconcentration technique (e.g., NTME; needle trap extraction and ITEX; in tube extraction) requires shorter incubation time but generates better intensity (Mochalski et al, 2018 ) and should be applicable to single cell studies as well (Serasanambati et al, 2019 ). For this reason, we developed an active sampling approach for monotrap-based sample preparation which is suitable for cellular VOC analysis.…”

The smell of longevity: a combination of Volatile Organic Compounds (VOCs) can discriminate centenarians and their offspring from age-matched subjects and young controls

“…CAN_1 variable markedly separated Y from the other three groups and the discriminant VOCs involved were 2-butanone, isopropyl alcohol, 2-pentanone, 3penten-1-ol, and pyrrole. These VOCs were detected in the urine of healthy subjects but also, in some cases with higher levels, in patients with different pathologies, such as cancer, nephropathy, and metabolic disorders (Silva et al 2012;Wang et al 2017;Mochalski et al 2018;Jia et al 2019). In our samples, these VOCs were more associated with Y group as they showed a higher correlation with CAN1.…”

Volatomic pattern of breast cancer and cancer-free tissues as a powerful strategy to identify potential biomarkers

“…Some of these have been already reported in the literature, namely acetic acid was found as a discriminant when associated with controls (CTL) in a study conducted by Ahmed et al 20 that investigated the possibility of faecal VOMs as potential diagnostic biomarkers for inflammatory bowel disease. Mochalski et al 21 investigated the emission of volatile compounds from gastric cancer tissues and non-cancerous tissues with the aim of identifying characteristic chemical patterns associated with gastric cancer. Furthermore, Silva et al 10,12 also reported phenols as the major chemical family identified in urine from the oncologic group.…”