Hypoxia promotes cancer progression, and metastasis. The major protein expressed in hypoxic solid cancer is hypoxia-inducible factor 1 (HIF1). We show that enhanced phosphorylation of a conventional protein kinase C isoform, PKCá, at threonine 638 (T(638)) by hypoxia-mimetic cobalt chloride induces HIF1á in nuclei of gastric epithelial cells (GECs). Moreover, phospho-T(638)-PKCá (P-PKCá) interacts with p300-HIF1á complex in the nuclei of hypoxic GECs and PKCá phosphorylation at T(638) enhances transcriptional activity of HIF1á. High P-PKCá expression in neoplastic gastric cancer biopsy samples as compared to nonneoplastic samples suggests that P-PKCá might act as an indicator of gastric cancer progression.
Cell Hypoxia Cell Line