title: Effect of progesterone receptor status on maspin synthesis via nitric oxide production in neutrophils in human breast cancer.
abstract: BACKGROUND
  Although progesterone receptor (PR) status, similarly to estrogen receptor status, is of prognostic importance in breast cancer, the involvement of the PR in breast cancer remains obscure. Studies were conducted to determine the function of the PR in neutrophils in the nitric oxide-induced synthesis of maspin, an anti-breast-cancer protein produced in nonmalignant mammary cells and in neutrophils in the circulation.
  
  
  METHODS
  PR status was determined by immunohistochemistry. Maspin synthesis was determined by in-vitro translation of messenger RNA and quantified by enzyme-linked immunosorbent assay. Nitric oxide was determined by the methemoglobin method.
  
  
  RESULTS
  It was found that PR status in neutrophils was identical with that in malignant breast tissues. A Scatchard plot for progesterone binding to normal and PR-positive (PR+) neutrophils revealed that whereas normal neutrophils had 11.5 × 10(10) PR sites/cell with K d = 47.619 nM, PR+ neutrophils had 6.6 × 10(10) PR sites/cell with K d = 47.619 nM. The progesterone negative (PR-) neutrophils failed to bind to progesterone. Incubation of normal and PR+ neutrophils with 25 nM progesterone produced 1.317 μM NO and 2.329 nM maspin; the PR+ neutrophils produced 0.72 μM NO and 1.138 nM maspin. The PR- neutrophils failed to produce any NO or maspin in the presence of progesterone. Inhibition of progesterone-induced NO synthesis led to complete inhibition of maspin synthesis in all neutrophils.
  
  
  CONCLUSIONS
  These results suggest that estrogen and progesterone complement each other in NO-induced maspin synthesis, and do not necessarily antagonize in the synthesis of the anti-breast-cancer protein.
authors.affiliation: Sinha Institute of Medical Science and Technology, 288, Kendua Main Road, Garia, Kolkata, 700084, India.
authors.forename: Karabi
authors.initials: K
authors.lastname: Ganguly Bhattacharjee
authors.forename: Mau
authors.initials: M
authors.lastname: Bhattacharyya
authors.forename: Umesh Chandra
authors.initials: UC
authors.lastname: Halder
authors.forename: Pradipta
authors.initials: P
authors.lastname: Jana
authors.forename: Asru K
authors.initials: AK
authors.lastname: Sinha
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism*; D016022:Case-Control Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008875:Middle Aged; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis*; D011374:Progesterone / Q000378:metabolism / Q000494:pharmacology; D011817:Rabbits; D011980:Receptors, Progesterone / Q000378:metabolism*; D015843:Serpins / Q000235:genetics / Q000378:metabolism*
chemical_list: D011980:Receptors, Progesterone; C085344:SERPIN-B5; D015843:Serpins; D009569:Nitric Oxide; D011374:Progesterone