Trophoblast glycoprotein (5T4 oncofetal glycoprotein) (5T4)

Trophoblast glycoprotein, commonly known as 5T4 oncofetal glycoprotein, is a 72 kDa leucine-rich repeat transmembrane protein (UniProt Q13641). It is primarily expressed during embryonic development in the trophoblast but is highly upregulated in a wide range of solid tumors, including colorectal, ovarian, and renal cell carcinomas (PubMed: 25973321). In adult tissues, its expression is extremely restricted to certain specialized epithelia, which provides a favorable therapeutic window for oncology treatments. Biologically, 5T4 plays a significant role in cell adhesion, motility, and the modulation of Wnt signaling, particularly the planar cell polarity pathway (PubMed: 19047085). This modulation facilitates the epithelial-mesenchymal transition (EMT), a process critical for tumor metastasis and the maintenance of cancer stem cell properties. Because of its tumor-specific expression pattern and role in disease progression, 5T4 has been targeted by various modalities, including antibody-drug conjugates (ADCs) and cancer vaccines (PubMed: 21455224). For example, the ADC PF-06263507 was designed to deliver a microtubule inhibitor directly to 5T4-positive cells (PubMed: 26370363). Additionally, viral-vectored vaccines like TroVax aim to stimulate the patient's immune system to recognize and destroy 5T4-expressing malignant cells. These therapeutic strategies exploit the protein's stable surface localization and its association with poor clinical prognosis in cancer patients.

Other names

TPBG5T4 antigenWnt-activated inhibitory factor 1WAIF1M6P1

Targeted delivery of cytotoxic agents via antibody-drug conjugates (ADCs), induction of tumor-specific immune responses through viral-vectored vaccines, and T-cell redirection via bispecific antibodies.