title: Differential processing of neuropeptide proprotein in human breast adenocarcinoma.
abstract: BACKGROUND
  The processing of proprotein convertase (PC)-mediated neuropeptide plays a very important role in carcinogenesis and tumor proliferation.
  
  
  OBJECTIVE
  To investigate proneuropeptide processing mechanism in tumorigenesis and tumor proliferation.
  
  
  METHODS
  The expression and processing profiles of PC1, carboxypeptidase E (CPE), PC2, GHRH, or neuropeptide Y (NPY) gene and protein level were investigated between 42 human breast tumor tissues and 21 tumor-adjacent normal tissues.
  
  
  RESULTS
  Gene analyses indicated that the proPC1, CPE, or preproNPY gene had higher expression in the breast tumor tissues, whereas the proPC2 or preproGHRH gene showed lower expression in the tissues. Protein analyses showed that the proPC1, PC1, CPE, GHRH, and preproNPY proteins were upregulated in the tumor tissues, whereas the proPC2, PC2, preproGHRH, and NPY proteins were down-regulated in them. The tissue results were highly corroborated with the serum data from the tumor patients and healthy women.
  
  
  CONCLUSIONS
  The higher PC1 and CPE expressions as well as the transformation of more proGHRH into active GHRH peptide suggest stronger PC1/CPE-mediated neuropeptide processing in the tumor, whereas the lower PC2 expression as well as the transformation of less proNPY into active NPY peptide suggests a weak PC2-mediated processing in it. The alterations of the convertase expressions and processing show that there is a differential proprotein processing system in the tumor, which leads to the abnormal distributions of species, ratio, and concentration of (pro)peptide(s) in the microenvironment of cells. The latter may contribute to cancer progression.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Basic Courses, Guangdong Pharmaceutical University, Guangzhou, China.
authors.forename: J H
authors.initials: JH
authors.lastname: Zhang
authors.forename: D
authors.initials: D
authors.lastname: Zhou
authors.forename: J
authors.initials: J
authors.lastname: You
authors.forename: B S
authors.initials: BS
authors.lastname: Tang
authors.forename: P Y
authors.initials: PY
authors.lastname: Li
authors.forename: S S
authors.initials: SS
authors.lastname: Tang
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism*; D000328:Adult; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism*; D043423:Carboxypeptidase H / Q000235:genetics / Q000378:metabolism*; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D045664:Proprotein Convertase 1 / Q000235:genetics / Q000378:metabolism*; D045706:Proprotein Convertase 2 / Q000235:genetics / Q000378:metabolism*; D043484:Proprotein Convertases / Q000235:genetics / Q000378:metabolism*; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism
chemical_list: D011498:Protein Precursors; C047524:pre-pro-growth hormone releasing factor; D013007:Growth Hormone-Releasing Hormone; D043423:Carboxypeptidase H; D043484:Proprotein Convertases; D045664:Proprotein Convertase 1; D045706:Proprotein Convertase 2