title: Hyaluronan and its receptors in mucoepidermoid carcinoma.
abstract: BACKGROUND
  Hyaluronan (HA) is a prominent extracellular matrix component undergoing continuous production and degradation. Increased HA levels have been described in a variety of tumors. The objective of this study was to examine the staining patterns of HA and two of its associated receptors (CD44 and HARE) in relation to the metastatic potential of mucoepidermoid carcinoma (MC). Immunohistochemical staining of preserved surgical specimens was used.
  
  
  METHODS
  Tissues from 12 patients with a histologic diagnosis of salivary MC (10 parotid, one submandibular gland, one minor salivary gland) were studied. Half (six of 12) of the patients had regional metastases. Tumor, normal salivary tissue, and regional lymph nodes were stained for HA, CD44, and HARE expression. Specimens were graded for staining intensity and a percent of the specimen stained.
  
  
  RESULTS
  Normal salivary tissue did not demonstrate epithelial cell surface HA expression, whereas HA was expressed on tumor cells and in regional lymph nodes containing metastases. These differences were both significant using Student's t test (p < .00002, and p < .0022, respectively). Tumors with positive nodes tended to have greater cell surface HA. Decreased expression or downregulation of HARE was also noted in involved lymph nodes. No differences in CD44 expression were seen between primary specimens and lymph nodes. The observed staining patterns for CD44 and HARE were not reflective of the metastatic potential of the primary MC.
  
  
  CONCLUSIONS
  Increased HA expression was seen on mucoepidermoid carcinoma cells compared with adjacent normal salivary gland epithelium. This observation may assist in explaining the development of regional metastasis in these tumors. We did not identify specific HA, CD44, or HARE staining patterns in primary lesions that were predictive of regional metastases.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Rochester Medical Center, Rochester, New York, USA.
authors.forename: Richard O
authors.initials: RO
authors.lastname: Wein
authors.forename: Carl T
authors.initials: CT
authors.lastname: McGary
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Doerr
authors.forename: Saurin R
authors.initials: SR
authors.lastname: Popat
authors.forename: John L
authors.initials: JL
authors.lastname: Howard
authors.forename: Janet A
authors.initials: JA
authors.lastname: Weigel
authors.forename: Paul H
authors.initials: PH
authors.lastname: Weigel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D018277:Carcinoma, Mucoepidermoid / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis*; D006820:Hyaluronic Acid / Q000032:analysis*; D008198:Lymph Nodes / Q000737:chemistry / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012468:Salivary Gland Neoplasms / Q000737:chemistry / Q000378:metabolism / Q000473:pathology*
chemical_list: D014408:Biomarkers, Tumor; D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid