FAP Antibody

Fibroblast activation protein (FAP) is a cell surface glycoprotein serine protease involved in extracellular matrix (ECM) degradation. It plays a crucial role in various cellular processes, including tissue remodeling, fibrosis, wound healing, inflammation, and tumor growth. Both membrane-bound and soluble forms exhibit post-proline cleaving endopeptidase activity, preferentially targeting Ala/Ser-Gly-Pro-Ser/Asn/Ala consensus sequences in substrates such as α2-antiplasmin (SERPINF2) and SPRY2. FAP also degrades gelatin and heat-denatured type I collagen but not native collagen types I and IV, vitronectin, tenascin, laminin, fibronectin, fibrin, or casein. Furthermore, FAP possesses dipeptidyl peptidase activity, hydrolyzing the prolyl bond two residues from the N-terminus of specific dipeptide substrates, particularly those with a penultimate proline residue (e.g., Ala-Pro, Ile-Pro, Gly-Pro, Arg-Pro, and Pro-Pro). Neuropeptides such as neuropeptide Y (NPY), peptide YY (PYY), substance P (TAC1), and brain natriuretic peptide 32 (NPPB) serve as natural substrates. The membrane-bound form of FAP, often in association with DPP4, PLAUR, or integrins, contributes to pericellular ECM proteolysis, facilitating cell adhesion, migration, and invasion. FAP is implicated in tissue remodeling during development and wound healing. In malignant melanoma, it enhances cell invasiveness. Its contribution to tumor growth progression involves increased angiogenesis, collagen fiber degradation, apoptosis induction, and suppression of antitumor immune responses. In gliomas, FAP promotes invasion through the brain parenchyma by degrading the proteoglycan brevican. Interestingly, it can also function as a tumor suppressor in melanocytic cells via serine protease activity-independent regulation of cell proliferation and survival.

1. FAP's near absence in normal tissues, coupled with its presence in embryonic and tumor tissues, makes it an attractive therapeutic target. This study explores strategies for targeting CAFs through FAP inhibition. PMID: 30383930
2. This research confirms FAPα's role in promoting the generation of Tregs and TAMs, highlighting its immunosuppressive function within the tumor microenvironment. PMID: 29273462
3. Evidence suggests that miR-30a-5p directly targets and suppresses FAP expression in oral squamous cell carcinoma (OSCC), inhibiting cell proliferation, migration, and invasion. This miRNA could be a novel therapeutic target for oral cancer. PMID: 29026005
4. This study demonstrates that FAPα enhances the growth, adhesion, and migration of lung squamous cell carcinoma cells, potentially through the PI3K and SHH pathways. Further research is needed to clarify its role in lung adenocarcinoma cells. PMID: 29115573
5. Multiple DPP-IV and FAP isoforms are present in glioblastoma tissue; however, the absence of alkaline isoforms in glioma cell lines suggests that stromal cells contribute to the overall enzymatic activity observed in glioblastoma. PMID: 28452380
6. Low plasma FAPα levels may be a systemic response to tumor presence, suggesting potential utility as a diagnostic biomarker for esophageal squamous cell carcinoma (ESCC). PMID: 28415791
7. Large tumor size, intra-abdominal location, multiple tumors, and younger patient age are predictive factors for FAP expression in desmoid tumors. PMID: 28570749
8. FAP is a potential prognostic marker for gastric cancer (GC) and a promising target for synergistic therapies, particularly in combination with immune checkpoint inhibitors. PMID: 27983931
9. Mutations in transmembrane (TM) interfacial residues (G10L, S14L, and A18L) within a small-X3-small motif reduce FAP TM-CYTO dimerization and endopeptidase activity, affecting cell surface expression. PMID: 27155568
10. Increased expression of proCOL11A1, FAP, SPARC, and periostin is observed in the intratumoral stroma of pancreatic ductal adenocarcinomas compared to non-neoplastic pancreatic tissue. PMID: 29025374
11. Strong correlation exists between circulating FAP activity and antigen levels in liver and coronary heart disease. PMID: 28582421
12. Fibroblast activation protein (FAP) is a stronger predictor of clinical aggressiveness in clear cell renal cell carcinoma than tumor grade and stage (P=.00117). PMID: 27063470
13. FAP expression in primary tumors and metastases is associated with both synchronous and lymph node metastases. PMID: 28033421
14. FAP is identified as the endopeptidase responsible for site-specific cleavage of human FGF21 (hFGF21), suggesting FAP inhibition as a therapeutic strategy to increase active FGF21 levels. PMID: 27118870
15. DPP4 activity and/or structure homologue (DASH) proteins, including DPP4 and FAP, are involved in various pathophysiological processes and are considered potential biomarkers or drug targets in cancers (Review). PMID: 26671446
16. FAP expression is significantly upregulated in human masticatory mucosa during wound healing. PMID: 28005267
17. Stromal FAPα expression is associated with distant metastasis in breast phyllodes tumors. PMID: 27881889
18. High FAPα expression is associated with glioblastoma. PMID: 27492457
19. Increased FAPα expression is associated with thyroid papillary carcinoma. PMID: 26715280
20. Comparable FAP expression levels in NGP-127, SJCRH30, SJSA-1 cell lines and cancer-associated fibroblasts suggest their suitability as models for FAP research. PMID: 27817025
21. FAP efficiently cleaves NPY, indicating a potential regulatory role in liver and cancer biology. PMID: 26621486
22. A degradomic study highlights the cell-context-dependent proteolysis by FAPα with distinct cleavage site preferences, linking FAPα to CAF biology and tumor-stroma interactions. PMID: 26304112
23. A DNA vaccine targeting human FAPα shows promise as a cancer immunotherapy strategy. PMID: 27020681
24. This study reveals FAP expression in activated fibroblasts post-myocardial infarction (MI) and its activation by TGFβ1, suggesting a role in cardiac wound healing. PMID: 26319660
25. Circulating fibroblast activation protein is identified as the protease responsible for hFGF21 inactivation. PMID: 26635356
26. FAP is expressed by activated, collagen-synthesizing fibroblasts in the infarct, but not by inactive fibroblasts, myofibroblasts, or non-fibroblast cells. PMID: 26454160
27. This study identifies fibroblast activation protein (FAP) as the enzyme that cleaves and inactivates human FGF21. PMID: 26797127
28. Human FGF-21 is a substrate of Fibroblast Activation Protein. PMID: 26962859
29. FAP selectively cleaves type I collagen, increasing macrophage adhesion. PMID: 26934296
30. FAP sensitizes fibrosarcoma to chemotherapy and modifies cell death pathways. PMID: 26342814
31. Simultaneous induction of FAP and DPP4 in dedifferentiating mature adipocytes suggests their involvement in adipose tissue remodeling and cell plasticity. PMID: 25816202
32. FAP expression is associated with a worse prognosis in solid tumors. PMID: 25775399
33. FAP deficiency promotes proteoglycan loss and cartilage degradation in chronic inflammatory arthritis. PMID: 25600705
34. Co-expression of FAP and DPP-IV is demonstrated in pancreatic alpha cells in adult humans. PMID: 25361590
35. CCN2, EMA, and FAP expression may be involved in the activation of cancer-associated fibroblasts in hepatocellular carcinoma. PMID: 25126747
36. Immunofluorescence microscopy confirms FAPα recruitment to lipid rafts and invadopodia. PMID: 26209915
37. High FAP expression is associated with increased metastasis. PMID: 25995078
38. Reduced soluble fibroblast activation protein plasma levels are observed in coronary heart disease. PMID: 25464232
39. Positive correlation exists between TGF-β1 and FAP-α expression in primary breast tumors. PMID: 25744843
40. FAP knockdown inactivates PTEN/PI3K/AKT and Ras-ERK signaling pathways, regulating proliferation, migration, and invasion in oral squamous cell carcinoma cells. PMID: 24722280
41. Studies on the substrate repertoire and expression patterns of FAP. PMID: 24470260
42. An association is observed between circulating FAPα levels and prognosis in acute coronary syndrome. PMID: 23932048
43. In vitro, FAP-α promotes breast cancer cell proliferation and inhibits migration, potentially via the FAK pathway. PMID: 24885257
44. FAP serves as a marker for cutaneous epithelial malignancy, aiding in the differential diagnosis of basal cell carcinoma, trichoepithelioma, squamous cell carcinoma, and pseudoepitheliomatous hyperplasia. PMID: 24595644
45. Positive correlation is found between FAP-α and DPPIV expression and gelatinase activity. PMID: 24789592
46. Immunohistochemical (IHC) staining for ADAM12, FAP, and WISP1 correlates with cancer recurrence rate, while SOX11 staining is lower in tumors with earlier recurrence. PMID: 24402778
47. FAP is essential for bone marrow mesenchymal stem cell migration through RhoA activation. PMID: 24551161
48. Seprase is transcriptionally upregulated in invasive melanoma cells via the canonical TGF-β signaling pathway, highlighting the roles of TGF-β and seprase in tumor invasion and metastasis. PMID: 24727589
49. The C1088T variant in fibroblast activation protein is associated with ER stress, loss of enzymatic function, and impaired cell surface localization. PMID: 24717288
50. FAPα may directly promote tumor growth and invasiveness in ovarian cancer cells. PMID: 24028972

HGNC: 3590

OMIM: 600403

KEGG: hsa:2191

STRING: 9606.ENSP00000188790

UniGene: Hs.654370