PROX1 Antibody #13910

Prospero homeobox protein 1 (PROX1) is a transcription factor known for its roles in organ development and lymphangiogenesis. It plays a critical role in the development of the CNS, lens, retina, liver, pancreas, and heart, and is considered to be the master regulator of the lymphatic system (1,2). PROX1 initiates the differentiation of lymphatic vasculature from the cardinal vein, where it is regulated by Sox18 (3,4). The PROX1 suppressor COUP-TFII represses the Notch pathway in venous endothelium, which prevents arterialization (4). HIF-1α and HIF-1β mediated hypoxia induces PROX1, which suggests a means of promoting lymphangiogenesis. Since the tumor microenvironment is typically hypoxic, regulation of PROX1 by hypoxia may also explain the up-regulation of this transcription factor in some cancers (2). PROX1 promotes colon cancer progression by down-regulating E-cadherin via miR-9, which promotes epithelial-mesenchymal transition (EMT) and metastasis (5). The PROX1 protein can act as a tumor suppressor in cases of hepatocellular carcinoma. PROX1 represses transcription of TWIST1, a transcription factor that promotes metastasis by binding the E-cadherin promoter. The function of PROX1 in other cancers is an area of active research (6).