Lysine Acetylome of Breast Cancer-Derived Small Extracellular Vesicles Reveals Specific Acetylation Patterns for Metabolic Enzymes

Abstract

Cancer-derived small extracellular vesicles have been proposed as promising potential biomarkers for diagnosis and prognosis of breast cancer (BC). We performed a proteomic study of lysine acetylation of breast cancer-derived small extracellular vesicles (sEVs) to understand the potential role of the aberrant acetylated proteins in the biology of invasive ductal carcinoma and triple-negative BC. Three cell lines were used as models for this study: MCF10A (non-metastatic), MCF7 (estrogen and progesterone receptor-positive, metastatic) and MDA-MB-231 (triple-negative, highly metastatic). For a comprehensive protein acetylation analysis of the sEVs derived from each cell line, acetylated peptides were enriched using the anti-acetyl-lysine antibody, followed by LC-MS/MS analysis. In total, there were 118 lysine-acetylated peptides, of which 22, 58 and 82 have been identified in MCF10A, MCF7 and MDA-MB-231 cell lines, respectively. These acetylated peptides were mapped to 60 distinct proteins and mainly identified proteins involved in metabolic pathways. Among the acetylated proteins identified in cancer-derived sEVs from MCF7 and MDA-MB-231 cell lines are proteins associated with the glycolysis pathway, annexins and histones. Five acetylated enzymes from the glycolytic pathway, present only in cancer-derived sEVs, were validated. These include aldolase (ALDOA), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoglycerate kinase (PGK1), enolase (ENO) and pyruvate kinase M1/2 (PKM). For three of these enzymes (ALDOA, PGK1 and ENO) the specific enzymatic activity was significantly higher in MDA-MB-231 when compared with MCF10A-derived sEVs. This study reveals that sEVs contain acetylated glycolytic metabolic enzymes that could be interesting potential candidates for early BC diagnostics.

Cargo exchange between human and bacterial extracellular vesicles in gestational tissues: a new paradigm in communication and immune development

“…The secretion of EVs is mediated by endosomal sorting complexes required for transport (ESCRT) pathway proteins and their homologs, and ESCRT-independent pathways [42][43][44] . Furthermore, EVs express specific transmembrane or lipid-bound extracellular and cytosolic protein markers [Table 1] [3,34,40,43,[45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] . Generally, exosomes are enriched in TSG101, ALIX, or HSP70 when the intraluminal vesicles (ILV) are formed through the ESCRT-dependent pathway.…”

Beyond the Usual Suspects: Examining the Role of Understudied Histone Variants in Breast Cancer

“…H2B D51 is an ADP-ribosylation site that is essential for p300-mediated acetylation inhibition of several lysine residues on H2B. Changes to acetylation patterns of histone H2B and histone acetyltransferases activity is common in breast cancer [ 166 , 167 ]. Therefore, the loss of ADP-ribosylation on H2B D51A/N mutations might disrupt the acetylation pattern on H2B, leading to significant changes in chromatin accessibility at enhancers and promoters, along with alterations in gene expression patterns.…”

Systematic proteomics analysis revealed different expression of laminin interaction proteins in breast cancer: lower in luminal subtype and higher in claudin-low subtype

“…In addition to BRCA1, BRCA2, and TP53 ( 3 - 5 ), many classical biomarkers exist ( 6 , 7 ); nevertheless, identifying new effective biomarkers and targets remains pivotal. With the emergence of proteomics, systematically investigating protein expression ( 8 , 9 ), modification ( 10 - 12 ), and classification ( 13 , 14 ) has become possible in breast cancer. Although more potential biomarkers and targets can be identified using this approach, such a complex method is bound to generate some inaccurate results.…”