hCG, five independent molecules

Introduction: The hCG amino acid sequence supports 5 glycoproteins. All are called hCG forms. This review examines all 5 molecules, the hormone as produced by the placental syncytiotrophoblast cells, the sulfated hormone produced by the pituitary gonadotrope cells, the hyperglycosylated hCG autocrine made by placental cytotrophoblast cells, and the autocrine cancer promoters hyperglycosylated hCG, hCG beta and hyperglycosylated hCG beta as made by all malignancies. This review examines all the molecules and multiple proven functions, ranging from evolution to cancer promotion to hormone action. Results and discussion: hCG forms are critical super-growth factors in humans, with an exceptional wide range of functions. (C) 2011 Elsevier B.V. All rights reserved.