nfP2X7 is a tumour-specific form of the P2X7 ligand-gated ion channel, consisting of three identical protein subunits.

When exposed to high concentrations of extracellular adenosine triphosphate (ATP), P2X7 forms a channel, driving a range of diverse physiological functions including proliferation and immune cell functions. Under prolonged stimulation, P2X7 can form a membrane pore that’s associated with induction of cell death. Additional published data reaffirms P2X7’s links to cancer cell survival and metastatic potential.

Biosceptre researchers found that a different form of P2X7 is expressed by cancer cells – one that’s unable to open the large pore that drives cell death. Hence, nfP2X7 or non-functional P2X7. The expression of nfP2X7 enables cancer cells to survive in the tumour environment where high, sustained levels of ATP would otherwise kill fully functional P2X7 cells.

Our studies have shown that nfP2X7 retains critical signalling capabilities that support cancer cell survival. Due to its modified state, nfP2X7 possesses novel epitopes that are available for antibody binding, and importantly, aren’t detected at the surface of functional P2X7. Targeting cancer cells via these nfP2X7 epitopes offers great specificity and is the basis of our technology.

Biosceptre has shown that nfP2X7 is widely expressed on a broad range of cancer cells including lung, breast, colorectal and prostate.