During Phase 1 studies under this proposal, the Investigators found a structurally distinct form of basic fibroblast growth factor (bFGF) which was released from a cell line derived from a human nasopharyngeal carcinoma. They demonstrated that the release of bFGF was not accomplished by increased cell lysis and/or cell death, suggesting that bFGF was released through an active process and that this release might have a functional role in regulating angiogenesis. Release of this factor was also demonstrated in other cell lines with high levels being released from various tumor and transformed cell lines and low or nondetectable levels from normal cell lines when the same number of cells were compared. When they compared transformed and nontransformed cells with the same genetic background, the transformed cells releated high levels of bFGF. Moreover, they were able to show that the release of bFGF appeared to be regulated at the post transcriptional level. It was enhanced by an specific stimulator of protein kinase activity and thus protein phophorylation appeared to be an essential step in the upregulation of release of bFGF. They analyzed a number of clinical samples and found higher levels of bFGF were present in some patients with neoplasia. This lead to the Phase II application in which the released bFGF will be studied to ascertain if it can be utilized as a tumor marker for potential clinical diagnosis and as a possible target for anti- angiogenesis therapy. In the current proposal, the Investigators plan to develop a radioimmunoassay for bFGF for the clinical detection and follow-up of patients with various neoplastic disorders. Initially, they plan to generate a panel of monoclonal antibiodies with different epitope specificities using recombinant bFGF as the antigen. Epitope specific mAbs will be employed to develop highly sensitive bFGF immuno-assay kits and then they will assess the clinical significance of bFGF release in various cancers using a bFGF immuno-assay system. Secondly, they will initiate efforts to identify, characterize and clone the cDNA to a bFGF binding protein observed in conditioned media from a human hepatocarcinoma cell line. They will employ a bFGF binding protein which they isolated from a human hepatocellular carcinoma cell line in order to use bFGF as a tumor marker and pursue a significance in anti-angiogenesis therapy. In this regard, they plan to generate a bFGF fusion protein by recombinant technology which can be used a specific probe to detect the bFGF binding protein in order to purify and assess the signficiance of bFGF binding protein. Antibodies against the bFGF binding protein will be generated and tested with clinical samples from patients with cancer.Thus, both the bFGF mAbs and the binding protein will be tested as reagents for clinical testing and then as part of a strategy to develop anti-angiogenesis agents by reducing or eliminating tumor formation in a nude mice model. Lastly, they plan to further purify and characterize other growth factor(s) and growth inhibitors secreted by nasopharyngeal carcinoma cell lines and a human hepatoma cell line.
