key: cord-103770-4svaq0at
authors: Ogrodzinski, Martin P.; Lunt, Sophia Y.
title: Metabolomic profiling of mouse mammary tumor derived cell lines reveals targeted therapy options for cancer subtypes
date: 2019-10-07
journal: bioRxiv
DOI: 10.1101/796573
sha: 
doc_id: 103770
cord_uid: 4svaq0at

Breast cancer is a heterogeneous disease with several subtypes that currently do not have targeted therapy options. Metabolomics has the potential to uncover novel targeted treatment strategies by identifying metabolic pathways required for cancer cells to survive and proliferate. Here, we used tumor-derived cell lines derived from the MMTV-Myc mouse model to investigate metabolic pathways that are differentially utilized between two subtypes of breast cancer. Using mass spectrometry-based metabolomics techniques, we identified differences in glycolysis, the tricarboxylic acid cycle, glutathione metabolism, and nucleotide metabolism between subtypes. We further show the feasibility of targeting these pathways in a subtype-specific manner using metabolism-targeting compounds.

Breast cancer is a heterogeneous disease with subtypes that vary by morphology, in 15.7% of human breast cancers and is more common in high grade tumors and the basal-like 62 subtype. 17 As a transcription factor, Myc affects numerous biological processes including 63 metabolism. 18, 19 Notably, Myc expression regulates several genes in glucose, amino acid, and 64 nucleotide metabolism. 20-22 Therefore, investigating metabolism of the MMTV-Myc model system may reveal metabolic features common to human cancer and could present new targeted 66 therapeutic options.

Here, we present a study investigating the metabolic profiles of two histologically distinct 

To determine metabolic profiles of histologically distinct mouse mammary tumor subtypes, 84 polar metabolites were extracted from tumor-derived cell lines and quantitated using LC-MS/MS.

We found metabolites involved in several central carbon metabolic pathways to be differentially 86 abundant between EMT and papillary tumor-derived cell lines (Figure 2 ).

In the EMT subtype, both oxidized and reduced forms of glutathione, a key metabolite in 88 redox homeostasis, are elevated ( Figure 2B ). Increased levels of both reduced and oxidized 89 glutathione imply that the EMT subtype has elevated glutathione biosynthetic activity. This could 90 reflect a greater dependency on glutathione biosynthesis in the EMT cells and targeting 91 glutathione biosynthesis would therefore be more effective against the EMT subtype. Metabolites 92 increased in the papillary subtype include fructose bisphosphate (FBP; glycolysis); acetyl-CoA indicating relative metabolite differences between EMT and papillary tumor derived cell lines. Metabolites are sorted by relationship to metabolic pathways. Yellow and blue boxes indicate increased or decreased metabolite levels relative to the average of the papillary subtype, respectively. Data for each sample is normalized to the average signal for all metabolites in the analysis. Metabolites with statistically significant differences (p-value < 0.05) are bolded and marked with asterisks (*). (B) Representative bar graphs of metabolites with statistically significant differences between EMT and papillary subtypes. Data are displayed as means ± S.D., N = 6.

A B * * * * metabolic pool size measurements to reveal more complete metabolic profiles. 24 We find the 108 papillary subtype has proportionally lower abundance of 13 

and ATP, as well as ribulose-5-phosphate and ribose-5-phosphate, two intermediates in the PPP production or decreased nucleotide consumption, we applied the same isotope labeling 

Molecular portraits of human breast tumours

Non-redox-active lipoate derivates disrupt cancer cell mitochondrial

Open source clustering software

Java Treeview-extensible visualization of microarray data

IsoCor: correcting MS data in isotope

Supplementary Figure 1: 13 C-Isotope labeling from glutamine into the TCA cycle is similar between subtypes. Cells were incubated in 13 C-glutamine containing media for four hours and extracted for metabolites. Grey boxes represent the unlabeled proportion for each metabolite at four hours. Green boxes represent the sum of all potential isotopologues for each metabolite

Supplementary Figure 2: 13 C-Isotope labeling from glucose into ribose 5-phospahte, serine, and glycine and from glutamine into aspartate is similar between subtypes. Cells were

Grey boxes represent the unlabeled proportion for each metabolite at four hours. Colored boxes represent isotopologues for each metabolite and are sorted based on carbon source