Alkaline phosphatase, placental-like 2 (ALPPL2) (ALPPL2)

Alkaline phosphatase, placental-like 2 (ALPPL2), also known as germ cell alkaline phosphatase (GCAP), is a membrane-bound enzyme belonging to the alkaline phosphatase family that catalyzes the hydrolysis of phosphate esters at alkaline pH (UniProt P10696). It is a glycosylphosphatidylinositol (GPI)-anchored protein primarily expressed during embryonic development and in the placenta, with very restricted expression in healthy adult tissues (NCBI Gene ID: 251). However, ALPPL2 is significantly overexpressed in several aggressive malignancies, including germ cell tumors, mesothelioma, and pancreatic ductal adenocarcinoma, where it may contribute to tumor cell proliferation and survival (PMID: 28819131, PMID: 32738235). Due to its high tumor specificity and cell-surface localization, ALPPL2 has emerged as a promising therapeutic target for next-generation immunotherapies, such as chimeric antigen receptor (CAR) T-cell therapy and antibody-drug conjugates (ADCs) (PMID: 33514621). Current clinical strategies focus on utilizing ALPPL2 as a diagnostic biomarker and a selective anchor for delivering potent cytotoxic payloads directly to the tumor microenvironment (PMID: 28819131).

Other names

Germ cell alkaline phosphataseGCAPNagao isoenzymeAlkaline phosphatase placental-likeALPPLALPG

Targeted immunotherapy via chimeric antigen receptor (CAR) T-cells or antibody-drug conjugates (ADCs), and competitive inhibition of phosphatase enzymatic activity.