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The presence and clinical implications of α-2,6-galactose-linked sialic acids in non-small-cell lung cancer brain metastases — preliminary study
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Abstract
Brain metastases (BM) in non-small-cell lung cancer (NSCLC) patients present an increasing clinical challenge. Identifying biomarkers which specifically identify patients at high risk of BM may improve their early diagnosis, which is crucial for surgical and radiotherapeutic treatment outcome. Alpha-2,6-sialyltransferase (α-2,6-ST) and the primary product of its activity, alpha-2,6-galactose-linked sialic acids (α-2,6-GalSA) have been found responsible for the adhesion of tumor cells to the brain vessels’ endothelium and enabling their transmigration through the blood-brain barrier in brain metastatic tumors. The aim of the study was to investigate by histochemical method the presence and possible role of α-2,6-GalSA in the formation of brain metastasis in NSCLC. In the screening phase 76 metastatic brain tumors were stained for α-2,6-GalSA and the second phase involved an identical staining of 20 primary tumors of patients who had their primary tumors treated with surgery or definite radiochemotherapy yet who later developed BM. The results were compared to a control group of 22 patients treated with surgery for NSCLC and who survived 5 years without the recurrence of disease. Alpha-2,6-GalSA presence was found to be down-regulated in poorly differentiated tumor types, whereas majority of differentiated tumors overexpressed it. This was statistically significant for both BM and the primary tumors. The expression of α-2,6-GalSA remained stable in primary and metastatic tumor pairs, however, no statistically significant differences were observed between study and control groups. Within the study group, a higher α-2,6-GalSA expression was associated with better overall survival, but not all statistical models found this result significant. Further studies are recommended to validate these findings.
Abstract
Brain metastases (BM) in non-small-cell lung cancer (NSCLC) patients present an increasing clinical challenge. Identifying biomarkers which specifically identify patients at high risk of BM may improve their early diagnosis, which is crucial for surgical and radiotherapeutic treatment outcome. Alpha-2,6-sialyltransferase (α-2,6-ST) and the primary product of its activity, alpha-2,6-galactose-linked sialic acids (α-2,6-GalSA) have been found responsible for the adhesion of tumor cells to the brain vessels’ endothelium and enabling their transmigration through the blood-brain barrier in brain metastatic tumors. The aim of the study was to investigate by histochemical method the presence and possible role of α-2,6-GalSA in the formation of brain metastasis in NSCLC. In the screening phase 76 metastatic brain tumors were stained for α-2,6-GalSA and the second phase involved an identical staining of 20 primary tumors of patients who had their primary tumors treated with surgery or definite radiochemotherapy yet who later developed BM. The results were compared to a control group of 22 patients treated with surgery for NSCLC and who survived 5 years without the recurrence of disease. Alpha-2,6-GalSA presence was found to be down-regulated in poorly differentiated tumor types, whereas majority of differentiated tumors overexpressed it. This was statistically significant for both BM and the primary tumors. The expression of α-2,6-GalSA remained stable in primary and metastatic tumor pairs, however, no statistically significant differences were observed between study and control groups. Within the study group, a higher α-2,6-GalSA expression was associated with better overall survival, but not all statistical models found this result significant. Further studies are recommended to validate these findings.
Keywords
alpha-2,6-sialic acids; NSCLC; brain metastases; survival; blood-brain barrier; CAMs
About this articleTitle
The presence and clinical implications of α-2,6-galactose-linked sialic acids in non-small-cell lung cancer brain metastases — preliminary study
Journal
Folia Histochemica et Cytobiologica
Issue
Article type
Original paper
Pages
104-111
Published online
2014-07-09
Page views
2639
Article views/downloads
2035
DOI
10.5603/FHC.2014.0012
Bibliographic record
Folia Histochem Cytobiol 2014;52(2):104-111.
Keywords
alpha-2
6-sialic acids
NSCLC
brain metastases
survival
blood-brain barrier
CAMs
Authors
Maciej J. Pelak
Bozena Jarosz
Anita Straczynska-Niemiec
Pawel Krawczyk
Piotr Skoczylas
Katarzyna M. Pecka
Miroslaw Snietura
Justyna Szumilo
Tomasz Trojanowski
