Western blot analysis of glycoproteins bearing Lewis(a) and sialyl-Lewis(a) antigens in human colorectal mucosa.
Glycoproteins (GPs) bearing Lewis(a) and sialyl-Lewis(a) antigens (Le(a), sialyl-Le(a)) derived from human colorectal carcinomas and their surrounding non-neoplastic mucosa (normal mucosa) were analyzed using Western blotting. GPs bearing Le(a) were detected mainly as segmental bands of M(r) 310, 220, 160, and 80 kDa in 80% of the normal mucosa, but these GPs were detected predominantly as broad bands ranging from high to low molecular weight (MW) in 71% of the carcinoma tissues. GPs bearing sialyl-Le(a) were detected only in 23% of the normal mucosa and limited on huge MW bands, i.e., more than 400 kDa, whereas these GPs were detected predominantly as broad bands in 49% of the carcinoma tissues. In the cases with lymph node metastasis, the MW of GPs bearing sialyl-Le(a) varied over a wide range and were detected as broad bands, compared with the cases without metastasis. In conclusion, the MW of GPs bearing Le(a) and sialyl-Le(a) in normal colorectal mucosa was different from that in colorectal carcinomas. That is, the MWs of GPs bearing Le(a) varied more in carcinoma tissues, and the GPs bearing sialyl-Le(a) from carcinoma tissues had lower MWs than those from normal mucosa. It was, furthermore, suggested that the increased expression of lower MW GPs bearing sialyl-Le(a) are associated with an increased metastatic potential of the tumor cells.
Takabayashi
T
T
Department of Surgery, Keio University Medical School, Tokyo, Japan.
Watanabe
M
M
Sakurai
Y
Y
Sugano
K
K
Kodaira
S
S
Kitajima
M
M
D015153:Blotting, Western; D018395:CA-19-9 Antigen; D003106:Colon / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D004591:Electrophoresis, Polyacrylamide Gel; D005732:Gangliosides / Q000032:analysis; D006023:Glycoproteins / Q000032:analysis* / Q000276:immunology; D006801:Humans; D007124:Immunoenzyme Techniques; D007413:Intestinal Mucosa / Q000378:metabolism*; D007519:Isoantigens / Q000032:analysis*; D007983:Lewis Blood Group Antigens / Q000276:immunology*; D012007:Rectum / Q000378:metabolism
D018395:CA-19-9 Antigen; D005732:Gangliosides; D006023:Glycoproteins; D007519:Isoantigens; D007983:Lewis Blood Group Antigens; C064564:sialyl Le(a) ganglioside