Table 1.
List of BCAF subpopulations in breast cancer.
| Subpopulation (s) | Functionality | Marker (s) | Ref. |
|---|---|---|---|
| CAF-S1 | Immunosuppression | FAP, αSMA, CXCL12, 1L6 | [38,41] |
| CAF-S2 | N/A | Low to negative expression of all biomarkers | |
| CAF-S3 | N/A | PDGFRβ | |
| CAF-S4 | Contractile signature, oxidative metabolism | αSMA, CD29 | |
| vCAFs | Vascular development and angiogenesis | NID2, CD31, αSMA, PDGFRβ | [41,51] |
| mCAFs | Provider of extracellular matrix and EMT | PDGFRα, FBLN1 | |
| cCAFs | Engage in cell cycle and cell division, angiogenesis | Ki-67, PDGFRβ | |
| dCAFs | Cell differentiation and development | SCRG1, SOX9 | |
| ECM-CAFs | EMT, ECM interaction and tissue remodelling | TNC | [41,53] |
| Inflammatory CAFs | Immunomodulation, monocyte recruitment | Ly6C, C3, CXCL12, PDGFRα | |
| Contractile myofibroblasts | Actin cytoskeleton organisation | αSMA, MYLK | |
| sCAFs | protein-folding and metabolic regulation | S100A4 | [54] |
| pCAFs | immune regulation, cell migration, wound healing | PDPN |
Abbreviations: BCAF, breast cancer-associated fibroblast; FAP, fibroblast activation protein; αSMA, alpha smooth muscle actin; CXCL12, C-X-C motif chemokine 12; 1L6, interleukin-6; PDGFRβ, platelet-derived growth factor receptor beta; CD29, cluster of differentiation 29; vCAFs, vascular cancer-associated fibroblasts; mCAFs, matrix cancer-associated fibroblasts; cCAFs, cycling cancer-associated fibroblasts; dCAFs, developmental cancer-associated fibroblasts; NID2, nidogen-2; CD31, cluster of differentiation 31; PDGFRα, platelet-derived growth factor receptor alpha; FBLN1, fibulin-1; Ki-67, antigen Ki-67; SCRG1, scrapie responsive gene 1, SOX9, SRY-Box transcription factor 9; TNC, tenascinC; Ly6C, lymphocyte antigen 6C1; C3, complement component 3; MYLK; myosin light chain kinase; S100A4, S100 calcium binding protein A4; PDPN, podoplanin; N/A, not applicable.