title: Using the matrix-induced ion suppression method for concentration normalization in cellular metabolomics studies.
abstract: Studies of the cell metabolome greatly improve our understanding of cell biology. Currently, most cellular metabolomics studies control only cell numbers or protein content without adjusting the total metabolite concentration, mainly because of the lack of an effective concentration normalization method for cell metabolites. This study proposed a matrix-induced ion suppression (MIIS) method to measure the total amount of cellular metabolites by utilizing flow injection analysis coupled with electrospray ionization mass spectrometry (FIA-ESI-MS).We used series dilutions of HL-60 cell extracts to establish the relationship between cellular metabolite concentration and the degree of ion suppression of the ion suppression indicator, and a good correlation was obtained between 2- and 12-fold dilutions of cell extracts (R(2) = 0.999). Two lung cancer cells, CL1-0 and CL1-5, were selected as the model cell lines to evaluate the efficacy of the MIIS method and the importance of metabolite concentration normalization. Through MIIS analysis, CL1-0 cells were found to contain metabolites at a concentration 2.1 times higher than in CL1-5, and the metastatic properties of CL1-5 could only be observed after 2.1-fold dilution of CL1-0 before metabolomic analysis. Our results demonstrated that the MIIS method is an effective approach for metabolite concentration normalization and that controlling metabolite concentrations can improve data integrity in cellular metabolomics studies.
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University , No. 33, Linsen S. Rd., Chongcheng Dist., Taipei, 10051 Taiwan.|The Metabolomics Core Laboratory, Center of Genomic Medicine, National Taiwan University , No.2, Xuzhou Rd., Zhongzheng Dist., Taipei 10055, Taiwan.
authors.forename: Guan-Yuan
authors.initials: GY
authors.lastname: Chen
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University , No. 33, Linsen S. Rd., Chongcheng Dist., Taipei, 10051 Taiwan.|The Metabolomics Core Laboratory, Center of Genomic Medicine, National Taiwan University , No.2, Xuzhou Rd., Zhongzheng Dist., Taipei 10055, Taiwan.
authors.forename: Hsiao-Wei
authors.initials: HW
authors.lastname: Liao
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University , No. 33, Linsen S. Rd., Chongcheng Dist., Taipei, 10051 Taiwan.|The Metabolomics Core Laboratory, Center of Genomic Medicine, National Taiwan University , No.2, Xuzhou Rd., Zhongzheng Dist., Taipei 10055, Taiwan.
authors.forename: I-Lin
authors.initials: IL
authors.lastname: Tsai
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University , No. 33, Linsen S. Rd., Chongcheng Dist., Taipei, 10051 Taiwan.|The Metabolomics Core Laboratory, Center of Genomic Medicine, National Taiwan University , No.2, Xuzhou Rd., Zhongzheng Dist., Taipei 10055, Taiwan.|Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University , No.1, Sec. 4, Roosevelt Rd., Zhongzheng Dist., Taipei 10090, Taiwan.|Department of Computer Science and Information Engineering, National Taiwan University , No.1, Sec. 4, Roosevelt Rd., Zhongzheng Dist., Taipei 10090, Taiwan.
authors.forename: Yufeng Jane
authors.initials: YJ
authors.lastname: Tseng
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University , No. 33, Linsen S. Rd., Chongcheng Dist., Taipei, 10051 Taiwan.|The Metabolomics Core Laboratory, Center of Genomic Medicine, National Taiwan University , No.2, Xuzhou Rd., Zhongzheng Dist., Taipei 10055, Taiwan.|Department of Pharmacy, National Taiwan University Hospital , No.7, Zhongshan S. Rd., Zhongzheng Dist., Taipei 10002, Taiwan.
authors.forename: Ching-Hua
authors.initials: CH
authors.lastname: Kuo
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism; D045744:Cell Line, Tumor; D017022:Flow Injection Analysis / Q000379:methods*; D006801:Humans; D007477:Ions / Q000737:chemistry; D008168:Lung / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism; D055442:Metabolome; D055432:Metabolomics / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D007477:Ions