A study on volatile organic compounds emitted by in-vitro lung cancer cultured cells using gas sensor array and SPME-GCMS

Abstract

Background: Volatile organic compounds (VOCs) emitted from exhaled breath from human bodies have been proven to be a useful source of information for early lung cancer diagnosis. To date, there are still arguable information on the production and origin of significant VOCs of cancer cells. Thus, this study aims to conduct in-vitro experiments involving related cell lines to verify the capability of VOCs in providing information of the cells.

Method: The performances of e-nose technology with different statistical methods to determine the best classifier were conducted and discussed. The gas sensor study has been complemented using solid phase micro-extraction-gas chromatography mass spectrometry. For this purpose, the lung cancer cells (A549 and Calu-3) and control cell lines, breast cancer cell (MCF7) and non-cancerous lung cell (WI38VA13) were cultured in growth medium.

Results: This study successfully provided a list of possible volatile organic compounds that can be specific biomarkers for lung cancer, even at the 24th hour of cell growth. Also, the Linear Discriminant Analysis-based One versus All-Support Vector Machine classifier, is able to produce high performance in distinguishing lung cancer from breast cancer cells and normal lung cells.

Conclusion: The findings in this work conclude that the specific VOC released from the cancer cells can act as the odour signature and potentially to be used as non-invasive screening of lung cancer using gas array sensor devices.

Keywords: E-nose; GCMS-SPME; In-vitro; Lung cancer; VOCs.

Fig. 1

The Cyranose 320 Setup for Data Collection: Snout of Cyranose 320 was inserted into the T-25cm² flask containing cell cultures

Fig. 2

Example of five complete cycles of the feature space extracted from sensor 12 of the e -nose using A549 sample at 24th hour

Fig. 3

The block diagram of data analysis conducted using Cyranose 320

Fig. 4

The GCMS-SPME odour sampling procedure. SPME coated needle was exposed to the headspace of cultured cell. The experiment was conducted in an incubator (37°C/5% CO₂)

Fig. 5

LDA plot of volatile compounds from cultured cells (combination of all 3 days). The separability of 4 types of cell lines and two different blank medium shows the effectiveness of the e-nose

Fig. 6

a PCA plot of volatile compounds of cultured cells (combination of all 3 days). The separability of 4 types of cell lines and two different blank medium shows the effectiveness of the e-nose. b PCA plot of volatile compounds of lung cancer cultured cells (combination of all 3 days). The separability of 2 types of lung cancer cell lines shows the effectiveness of the e-nose