title: Expression of underglycosylated MUC1 antigen in cancerous and adjacent normal breast tissues.
abstract: BACKGROUND
  Mucin 1 antigen (MUC1) is a high-molecular-weight transmembrane glycoprotein with an aberrant expression profile in various malignancies, including breast cancer. Its increased overexpression and underglycosylation in breast cancer is associated with tumor invasiveness and metastatic potential. In this study, we took the next step toward establishing MUC1 as a potential diagnostic, prognostic, and therapeutic target by investigating its expression and posttranslational modification (glycosylation/sialylation).
  
  
  METHODS
  In these studies we used a breast cancer tissue microarray (TMA) and fresh-frozen multistage breast cancer tissues. We analyzed in detail the expression of normal and underglycosylated/sialated MUC1 by immunohistochemical techniques, real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), and various analytic techniques.
  
  
  RESULTS
  We found that changes in cellular localization as well as in upregulation and/or underglycosylation of MUC1 were associated with higher tumor grade. A key finding in this study was that underglycosylated MUC1 (uMUC1) overexpression and sialation were observed in tissues adjacent to tumor but identified as normal on pathology reports.
  
  
  CONCLUSIONS
  These findings suggest that uMUC1 can indeed be used as an early diagnostic marker and provide additional insights into breast cancer management.
authors.affiliation: Molecular Imaging Laboratory, MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02129, USA.
authors.forename: Subrata K
authors.initials: SK
authors.lastname: Ghosh
authors.forename: Pamela
authors.initials: P
authors.lastname: Pantazopoulos
authors.forename: Zdravka
authors.initials: Z
authors.lastname: Medarova
authors.forename: Anna
authors.initials: A
authors.lastname: Moore
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D001940:Breast / Q000378:metabolism* / Q000473:pathology; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D042241:Early Diagnosis; D005260:Female; D005500:Follow-Up Studies; D006031:Glycosylation; D006801:Humans; D007124:Immunoenzyme Techniques; D008207:Lymphatic Metastasis; D018396:Mucin-1 / Q000235:genetics / Q000378:metabolism*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D009367:Neoplasm Staging; D009439:Neuraminidase / Q000378:metabolism; D011379:Prognosis; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012799:Sialyltransferases / Q000378:metabolism; D015996:Survival Rate; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; C060192:MUC1 protein, human; D018396:Mucin-1; D012333:RNA, Messenger; D012799:Sialyltransferases; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid