Characterization of Breast Cancer Interstitial Fluids by TmT Labeling, LTQ-Orbitrap Velos Mass Spectrometry, and Pathway Analysis

Cancer is currently considered as the end point of numerous
genomic
and epigenomic mutations and as the result of the interaction of transformed
cells within the stromal microenvironment. The present work focuses
on breast cancer, one of the most common malignancies affecting the
female population in industrialized countries. In this study, we perform
a proteomic analysis of bioptic samples from human breast cancer,
namely, interstitial fluids and primary cells, normal vs disease tissues,
using tandem mass tags (TmT) quantitative mass spectrometry combined
with the MudPIT technique. To the best of our knowledge, this work,
with over 1700 proteins identified, represents the most comprehensive
characterization of the breast cancer interstitial fluid proteome
to date. Network analysis was used to identify functionally active
networks in the breast cancer associated samples. From the list of
differentially expressed genes, we have retrieved the associated functional
interaction networks. Many different signaling pathways were found
activated, strongly linked to invasion, metastasis development, proliferation,
and with a significant cross-talking rate. This pilot study presents
evidence that the proposed quantitative proteomic approach can be
applied to discriminate between normal and tumoral samples and for
the discovery of yet unknown carcinogenesis mechanisms and therapeutic
strategies.