Human FAP Stable Cell Line - HPAF-II

Fibroblast activation protein alpha, commonly referred to as FAP, is a gene located on chromosome 2q24.2 that encodes a homodimeric integral membrane serine protease. This protein, also known as seprase or DPPIV-related protease, is selectively expressed in reactive stromal fibroblasts associated with epithelial cancers, wound healing granulation tissue, and certain malignant cells. Under normal physiological conditions, FAP expression is largely restricted to tissues undergoing active remodeling, making it an attractive target for cancer research and therapeutic development. The Human FAP Stable Cell Line - HPAF-II is a well-characterized pancreatic adenocarcinoma cell line originally derived from the peritoneal ascitic fluid of a 44-year-old Caucasian male patient diagnosed with primary pancreatic adenocarcinoma that had metastasized to the liver, diaphragm, and lymph nodes. HPAF-II is a spontaneous variant that emerged from a static culture of the parental HPAF-I cells and exhibits unlimited replicative capability. The cell line carries a KRAS G12D mutation, a TP53 P151S alteration, and a CDKN2A deletion, which collectively mirror the genetic landscape commonly seen in human pancreatic ductal adenocarcinoma.

This stable cell line has a broad range of research applications, particularly in the fields of oncology and drug development. Because HPAF-II cells endogenously express FAP on their surface, they serve as a physiologically relevant in vitro model for evaluating FAP-targeted therapies, including antibody-drug conjugates, bispecific antibodies, CAR-T cells, and small molecule inhibitors. Researchers frequently use this line to study FAP-mediated signaling pathways, cell proliferation, invasion, and tumor-stroma interactions. The cells are also employed in 3D culture systems and organoid models to better recapitulate the tumor microenvironment. In vivo, HPAF-II cells form well-differentiated adenocarcinomas in athymic mice that closely resemble the original patient tumor, making them suitable for xenograft studies and preclinical efficacy testing.