Presence of human breast cancer xenograft changes the diurnal profile of amino acids in mice

Rubens Paula Junior,Nathália Martins Sonehara,Bruna Victorasso Jardim-Perassi,Debora A P C Zuccari,Yasmin Asad,Roger Chammas,Akos Pal,Luiz Gustavo Almeida Chuffa,Florence I Raynaud

doi:10.1038/s41598-022-04994-6

Abstract

Human xenografts are extremely useful models to study the biology of human cancers and the effects of novel potential therapies. Deregulation of metabolism, including changes in amino acids (AAs), is a common characteristic of many human neoplasms. Plasma AAs undergo daily variations, driven by circadian endogenous and exogenous factors. We compared AAs concentration in triple negative breast cancer MDA-MB-231 cells and MCF10A non-tumorigenic immortalized breast epithelial cells. We also measured plasma AAs in mice bearing xenograft MDA-MB-231 and compared their levels with non-tumor-bearing control animals over 24 h. In vitro studies revealed that most of AAs were significantly different in MDA-MB-231 cells when compared with MCF10A. Plasma concentrations of 15 AAs were higher in cancer cells, two were lower and four were observed to shift across 24 h. In the in vivo setting, analysis showed that 12 out of 20 AAs varied significantly between tumor-bearing and non-tumor bearing mice. Noticeably, these metabolites peaked in the dark phase in non-tumor bearing mice, which corresponds to the active time of these animals. Conversely, in tumor-bearing mice, the peak time occurred during the light phase. In the early period of the light phase, these AAs were significantly higher in tumor-bearing animals, yet significantly lower in the middle of the light phase when compared with controls. This pilot study highlights the importance of well controlled experiments in studies involving plasma AAs in human breast cancer xenografts, in addition to emphasizing the need for more precise examination of exometabolomic changes using multiple time points.

Highlights

Human xenografts are extremely useful models to study the biology of human cancers and the effects of novel potential therapies
amino acids (AAs) are significantly altered in cancer cells across 24 h. 21 AAs were potentially detectable in both cell lines; with the exception of Citrulline (Cit) where the levels were not consistent and Ornithine (Orn) which was undetectable in normal breast cells, most of the metabolites were stable and did not vary across 24 h
Our study shows that mice bearing human breast cancer MDA-MB-231 xenografts exhibit broad differences in the rhythm of plasma AAs compared with the non-tumor bearing mice

Summary

Introduction

Human xenografts are extremely useful models to study the biology of human cancers and the effects of novel potential therapies. In the early period of the light phase, these AAs were significantly higher in tumor-bearing animals, yet significantly lower in the middle of the light phase when compared with controls This pilot study highlights the importance of well controlled experiments in studies involving plasma AAs in human breast cancer xenografts, in addition to emphasizing the need for more precise examination of exometabolomic changes using multiple time points. Per[2] Period Circadian Regulator 2 PFAA Plasma Free Amino Acids PLSDA Partial Least-Squares Discriminant Analysis PRODH Proline Dehydrogenase RCF Relative Centrifugal Force RORγ RAR-related Orphan Receptor Gamma SRB Sulfate-reducing Bacteria TAARs Trace Amino acids Receptors TQ-S Triple Quadrupole Spectrometer ZT Zeitgeber time Complex diseases such as cancer have been widely studied through omics analysis to understand the mechanism of oncogenesis and to identify new b iomarkers[1,2]. There is evidence that cancer cells possess the metabolic capability to repurpose their waste molecules, such as lactate from glucose oxidation and ammonia from AAs metabolism, recycling those for its own deregulated metabolism[8,9]

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