FGF-8b

FGF8 is identified as an androgen-induced growth factor secreted from a mammary carcinoma cell line and widely expressed during embryonic development. It has been shown to mediate embryonic epithelial-mesenchymal transition and to have a key role in gastrulation and early organization and differentiation of midbrain/hindbrain, pharyngeal, cardiac, urogenital and limb structures. During adulthood FGF8 expression is much more restricted but in hormonal cancers it becomes frequently activated. The FGF8 subfamily, including FGF8, FGF17 and FGF18, has been not only detected in prostate, breast cancer but also in hepatocellular carcinoma (HCC). FGF8, FGF17, and FGF18 are involved in autocrine and paracrine signaling in HCC and enhance the survival of tumor cells under stress conditions, malignant behavior, and neoangiogenesis. The vertebrate FGF8 gene produces multiple protein isoforms by alternative splicing. Two evolutionarily conserved spliceforms, FGF8a and FGF8b, exhibit distinct bioactivities, with Fgf8b having a more potent inductive activity due to higher affinity for FGF receptors.