title: sLea and sLex expression in colorectal cancer: implications for tumourigenesis and disease prognosis.
abstract: The glycoconjugates expressed by cancer cells frequently contain sialylated oligosaccharide chains. Among these oligosaccharides the sialyl Lewis a (sLe(a)) and sialyl Lewis x (sLe(x)) antigens are found to be overexpressed in tumours of different origin. The current study assesses sLe(a) and sLe(x) expression in different colorectal specimens in order to establish the correlation of these biomarkers with both malignant transformation of colorectal mucosa and the progression of colorectal cancer (CRC). Healthy disease-free and inflammatory mucosa specimens showed no presence of the antigens. sLe(a) was expressed in 6.7% of the healthy tissue from CRC patients, in 20.8% of the adenomas, and in 33.3% and 42.6% of the transitional tissue and tumour tissue, respectively. sLe(x) expression was observed in 6.7% of the healthy tissue from CRC patients, in 27.0% of the adenomas, and in 25.6% and 74.8% of the transitional and the tumour tissue, respectively. The expression of the sLe(a) and sLe(x) antigens was correlated in adenomas, as well as in healthy and tumour tissue from CRC. Moreover, the high expression of sLe(x) in adenomas was correlated with a high degree of dysplasia (p=0.042). Finally, the survival analysis suggested that sLe(a) expression may be a prognostic factor for predicting disease-free survival in colorectal cancer (p=0.012).
authors.affiliation: Department of Biochemistry, Genetics and Immunology, Faculty of Biology, University of Vigo, Spain.
authors.forename: S Villar
authors.initials: SV
authors.lastname: Portela
authors.forename: C Vázquez
authors.initials: CV
authors.lastname: Martín
authors.forename: L Muinelo
authors.initials: LM
authors.lastname: Romay
authors.forename: E
authors.initials: E
authors.lastname: Cuevas
authors.forename: E Gil
authors.initials: EG
authors.lastname: Martín
authors.forename: A Fernández
authors.initials: AF
authors.lastname: Briera
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000236:Adenoma / Q000378:metabolism / Q000473:pathology; D014408:Biomarkers, Tumor / Q000032:analysis / Q000378:metabolism*; D018395:CA-19-9 Antigen; D002471:Cell Transformation, Neoplastic / Q000378:metabolism / Q000473:pathology; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D018572:Disease-Free Survival; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D009367:Neoplasm Staging; D009844:Oligosaccharides / Q000096:biosynthesis*; D011379:Prognosis; D000080506:Sialyl Lewis X Antigen
chemical_list: D014408:Biomarkers, Tumor; D018395:CA-19-9 Antigen; D009844:Oligosaccharides; D000080506:Sialyl Lewis X Antigen