Mucinous (colloid) adenocarcinomas secrete distinct O-acylated forms of sialomucins: a histochemical study of gastric, colorectal and breast adenocarcinomas.
OBJECTIVE
Mucinous (colloid) adenocarcinomas represent a distinct group of tumours defined by the presence of large amounts of extracellular mucins. By using histochemical methods, we analysed mucins secreted by mucinous versus non-mucinous adenocarcinomas and looked for differential secretion profiles.


RESULTS
Sixty-four adenocarcinomas were studied (23 colorectal, 17 gastric, and 24 breast tumours). Thirty-two tumours were of the colloid type. The following methods were applied to paraffin tissue sections: (i) Alcian blue (pH 2.5) and periodic acid-Schiff (PAS); (ii) high iron diamine and Alcian blue (pH 2.5); (iii) periodic acid borohydride, potassium hydroxide, and PAS; (iv) periodic acid-thionine Schiff, potassium hydroxide, and PAS; and (v) periodic acid-borohydride and PAS. Most adenocarcinomas secreted acidic mucins, with sialomucins predominating over sulfomucins, except for non-mucinous adenocarcinomas of the breast which showed predominant neutral mucins. All mucinous adenocarcinomas contained C9-O-acyl sialic acid as mono, di(C8,C9)-, or tri(C7,C8,C9)-O-acyl forms. Acidic mucins secreted by the majority of non-colloid adenocarcinomas consisted of non-O-acylated sialomucins.


CONCLUSIONS
C9-O-acylation of sialic acid is a characteristic feature of mucinous adenocarcinomas and can be readily detected by histochemical methods.
Sáez
C
C
Laboratory of Histochemistry, Department of Pathology, Hospital Universitario Virgen del Rocío, Avenida Manuel Siurot s/n, Seville 41013, Spain.
Japón
M A
MA
Poveda
M A
MA
Segura
D I
DI
D000107:Acetylation; D002288:Adenocarcinoma, Mucinous / Q000378:metabolism / Q000473:pathology*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology; D006651:Histocytochemistry; D006801:Humans; D009077:Mucins / Q000378:metabolism*; D052116:Sialomucins; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology
D009077:Mucins; D052116:Sialomucins