Expression Of Human Growth Hormone And Human Prolactin In Hepatocarcinoma And Possible Utilization As Therapeutic Targets

Growth hormone and prolactin is belong to one family of growth factor, GH protein is composed of 191 amino acids residues,the molecular weight of which is 22 KDa,.PRL protein is composed of 199 amino acids residues,the molecular weight of which is 23 KDa.The structure of them are similar to each other, are about 60% of homology.A lot of related reserches have reported that growth hormone and prolactin play a key role in the occurrence and development of cancer.They reported that the growth hormone combines with its receptor,triggers receptors dimerization, then causes the expression of IGF-â… raised, and subsequently causes a series of biological effections such as cell proliferation. And the occurrence of prostate cancer, lung and colon cancer, breast cancer are closely linked with growth hormone. Prolactin combines with its receptor PRLR , causes the activation of downstream JAK2 and STAT proteins, and then produces a lot of biological effections,.Breast cancer, prostate cancer and genital tract cancer are confirmed to related to the overexpression of prolactin. Notable is, because of the structures of the two moleculars are very similar, GH can also combine with PRLR, and activate the signaling pathways downstream,then causes a series of biological effections in vivo. But PRL can not to recognize GHR.The aim of our suject is to study the functions and effections of GH and PRL in the development of hepatocarcinoma .We construct hepatocarcinoma cell lines stably transfected GH and PRL genes,and then identify the related functions of GH and PRL by functional experiment in vitro.To further illustrate the effections of GH and PRL,we construct hepatocarcinoma cell lines stably transfected G120R gene to inhibit the activity of GH and PRL.As the result that the viability of hepatoma cells ,non-anchored growth capacity and the ability of xenograft are promoted significantly with the overexpression of GH and PRL gene.The corresponding abilities are suppressed significantly when G120R inhibits the activation of their receptors.It suggests that GH and PRL play an important role in the development of hepatocarcinoma .And our study provodes a new perspective on clinical that we can inhibit hepatocarcinoma cell growth by using some drugs which is similar to G120R to suppress the activity of GH and PRL.We search for the downstream effective molecules to identified the mechanisms of GH, PRL involved. It is confirmed that overexpression of GH and PRL causes increased expression of IGF-â… which is identified by RT-PCR.We preliminarily think that IGF-â… play a mediating role in GH, PRL signal pathway.The depth exploration of the mechanism to be studied next in the futher.