Mass spectrometry imaging of L-[ring-13C6]-labeled phenylalanine and tyrosine kinetics in non-small cell lung carcinoma

Abstract

Background Metabolic reprogramming is a common phenomenon in tumorigenesis and tumor progression. Amino acids are important mediators in cancer metabolism, and their kinetics in tumor tissue are far from being understood completely. Mass spectrometry imaging is capable to spatiotemporally trace important endogenous metabolites in biological tissue specimens. In this research, we studied L-[ring-13C6]-labeled phenylalanine and tyrosine kinetics in a human non-small cell lung carcinoma (NSCLC) xenografted mouse model using matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry imaging (MALDI-FTICR-MSI). Methods We investigated the L-[ring-13C6]-Phenylalanine (13C6-Phe) and L-[ring-13C6]-Tyrosine (13C6-Tyr) kinetics at 10 min (n = 4), 30 min (n = 3), and 60 min (n = 4) after tracer injection and sham-treated group (n = 3) at 10 min in mouse-xenograft lung tumor tissues by MALDI-FTICR-MSI. Results The dynamic changes in the spatial distributions of 19 out of 20 standard amino acids are observed in the tumor tissue. The highest abundance of 13C6-Phe was detected in tumor tissue at 10 min after tracer injection and decreased progressively over time. The overall enrichment of 13C6-Tyr showed a delayed temporal trend compared to 13C6-Phe in tumor caused by the Phe-to-Tyr conversion process. Specifically, 13C6-Phe and 13C6-Tyr showed higher abundances in viable tumor regions compared to non-viable regions. Conclusions We demonstrated the spatiotemporal intra-tumoral distribution of the essential aromatic amino acid 13C6-Phe and its de-novo synthesized metabolite 13C6-Tyr by MALDI-FTICR-MSI. Our results explore for the first time local phenylalanine metabolism in the context of cancer tissue morphology. This opens a new way to understand amino acid metabolism within the tumor and its microenvironment.

Application of Surface-Enhanced Raman Spectroscopy in the Screening of Pulmonary Adenocarcinoma Nodules

“…The peak of 1004 cm −1 was ascribed to phenylalanine as a biomarker for lung cancer, whose aberrant metabolism may produce content changes [ 22 , 28 , 37 ]. The peaks at 1335 cm −1 and 1582 cm −1 were found to be tryptophan [ 28 ], and its relative SERS intensity was higher in the benign group but decreased in the malignant group, as shown in the previous finding [ 38 , 39 ].…”

Evidence of Stable Isotope 13C Causing All Cancers

“…Aspartame has been observed to inhibit plant growth [22]. The decomposition product from aspartame digestion phenylalanine has been observed to induce tumor cell line growth [23]. Such an effect of phenylalanine on accelerated tumor growth may result from phenylalanine replacing tryptophan in peptides and proteins for altered enzymatics and DNA and RNA [24].…”

Local metabolism in preclinical disease models studied with mass spectrometry imaging

“…For example, p-N,N,N-trimethylammonioanilyl N'-hydroxysuccinimidyl carbamate iodide (TAHS), is a derivatization reagent that briefly reacts with the amino group, leading to form derivatives of amino acids which are positively charged in the trimethylanilynium moiety (Figure 1.8) [78], resulting in a mass shift of 177.1022 Da. This leads to a significant improvement in ionization efficiency for multiple amino acids (Figure 1.9) [79,80]. The combination of on-tissue TAHS derivatization and MALDI-MSI has been successfully applied to mouse brain [79], human cancer xenografts [78,80] and mouse liver [81].…”

“…This leads to a significant improvement in ionization efficiency for multiple amino acids (Figure 1.9) [79,80]. The combination of on-tissue TAHS derivatization and MALDI-MSI has been successfully applied to mouse brain [79], human cancer xenografts [78,80] and mouse liver [81]. In addition to TAHS, trans-cinnamaldehyde, 4-hydroxy-3methoxycinnamaldehyde, 2,4-diphenyl-pyranylium tetrafluoroborate, 2-nitrobenzaldehyde and 2-fluoro-1-methyl pyridinium reagents can also react with amine groups and have been applied in MALDI-MSI on different tissues [77].…”

“…And finally, Arts et al revealed the localized hepatocellular synthesis of L-phenylalanine in mice with To conclude, isotope labeling together with MALDI-MSI harbors great potential for the investigation of the spatial dynamics of metabolic processes in many diseases, especially in cancer. Therefore, in chapter 5 of this thesis, I studied the kinetics of 13 C labeled Lphenylalanine and its derivative L-tyrosine in lung tumor xenografts over time [80].…”