Differential proteomic comparison of the breast cancer secretome using a quantitative paired analysis workflow

ABSTRACT: Worldwide, breast cancer is the main cause of cancer mortality in women. Most cases originate in mammary ductal cells that secrete the nipple aspirate fluid (NAF). In cancer patients, this breast secretome contains proteins associated with the tumor microenvironment. NAF studies are challenging because inter-individual variability is substantial. To better address this limitation, we introduced a paired-proteomic strategy that relies on NAF sample analysis from both breasts of patients with unilateral breast cancer. We developed a software extension to the PatternLab for Proteomics software to take advantage of this setup. Briefly, the software relies on a peptide-centric approach and uses the binomial distribution to attribute a probability for each peptide as being linked to the disease or not; these probabilities are then propagated to a final protein p-value according to the Stouffer’s Z-score method. Our approach was applied to both a discovery-driven (shotgun) analysis of NAF samples and a hypothesis-driven (targeted) assessment of 19 cancer-related proteins described in the literature. Shotgun results culminated in the reliable quantitative proteomic profiling of NAF samples from healthy and cancer cohorts. A total of 1,083 proteins were identified, of which 77 were differentially abundant, being mainly involved in glycolysis (Warburg effect) and immune system activation (activated stroma). Additionally, in the estrogen receptor-positive subgroup, proteins related to the lipid metabolism and the complement cascade displayed higher abundance, as expected for this well-differentiated subtype of cancer. The targeted analysis of NAF samples from triple negative patients revealed three differentially abundant proteins related to cell migration/attraction and tumor cell differentiation. In summary, we debuted a paired differential bioinformatics workflow, performing a proof-of-principal differential proteomic analysis of NAF samples in unilateral breast cancers patients. The results revealed a promising statistical paired analysis workflow, thus validating NAF as a treasure-trove for studying this paired-organ cancer type.

INSTRUMENT(S): LTQ Orbitrap Elite, Q Exactive

ORGANISM(S): Homo Sapiens (human)

DISEASE(S): Breast Cancer

SUBMITTER: Giselle Brunoro  

LAB HEAD: Jonas Perales

PROVIDER: PXD005157 | Pride | 2019-04-23

REPOSITORIES: Pride