title: Expression of fas ligand in metastatic prostatic carcinoma: suggestive of possible clonal expansion of subpopulation with metastatic potential.
abstract: Fas ligand (FasL) is a type II transmembrane tumor necrosis factor family protein, known to trigger apoptosis in cells that bear the FasL receptor, Fas. The authors found that normal prostate, benign hyperplasia, and most prostatic carcinoma cells at the primary site did not express FasL, whereas metastatic prostatic carcinoma cells in lymph nodes and bone marrow displayed almost uniform, immunohistochemically detectable, FasL expression. However, small foci of FasL-positive prostatic carcinoma cells amid a vast majority of FasL-negative tumor cells were noted at the primary sites in patients with distant metastases. Analysis of the FasL gene and its mRNA by polymerase chain reaction and reverse transcriptase-polymerase chain reaction, respectively, suggested that the expression of immunohistochemically detectable FasL in metastatic tumor cells was not due to mutation in the FasL gene with resulting overexpression. Further, FasL expression was detectable in the acinar epithelial cells of prostates with morphologic atrophic changes, suggesting that FasL also plays a role in the physiologic apoptosis process of noncancerous prostate. The current data suggest that a subpopulation of prostate carcinoma cells clonally expresses FasL, and this subpopulation may have metastatic potential. Evaluation of FasL expression in the primary tumor thus may provide a useful parameter for predicting metastatic potential of the tumor.
authors.affiliation: Department of Pathology, Columbia University College of Physicians & Surgeons, New York, New York, USA.
authors.forename: Y A
authors.initials: YA
authors.lastname: Yeh
authors.forename: J W
authors.initials: JW
authors.lastname: Wang
authors.forename: C Y
authors.initials: CY
authors.lastname: Fan
authors.forename: S L
authors.initials: SL
authors.lastname: MacLeod
authors.forename: K
authors.initials: K
authors.lastname: Fan
mesh_terms: D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology; D002277:Carcinoma / Q000378:metabolism* / Q000556:secondary; D002999:Clone Cells / Q000378:metabolism / Q000473:pathology; D004273:DNA, Neoplasm / Q000032:analysis; D053222:Fas Ligand Protein; D006801:Humans; D007124:Immunoenzyme Techniques; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D016133:Polymerase Chain Reaction; D011467:Prostate / Q000033:anatomy & histology / Q000378:metabolism / Q000473:pathology; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis
chemical_list: D004273:DNA, Neoplasm; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm