Expression of variant CD44-messenger RNA in colorectal adenocarcinomas and adenomatous polyps in humans.
OBJECTIVE
Recent studies have shown that some variant forms of CD44, a transmembrane glycoprotein expressed on various cell surfaces, might be involved in tumor progression or tumor metastasis. The aim of this study was to analyze the expression of CD44-messenger RNA (mRNA) in colorectal cancer and colorectal adenoma to further elucidate the role of CD44 in colorectal tumorigenesis.


METHODS
The expression of CD44-mRNA was examined in 90 specimens from 44 patients with colorectal cancer or colorectal adenomatous polyps and in the peripheral blood leukocytes from 7 healthy volunteers by reverse transcription-polymerase chain reaction and Southern blot hybridization.


RESULTS
Strong expression of the epithelial form and variant forms containing exons 11 or 12 of the CD44 gene, which conferred metastatic behavior to rat cells, was detected in primary and metastatic tumor tissues, whereas it was very weak or not detectable in normal colonic mucosae, normal liver tissue, or peripheral blood leukocytes. However, adenomatous colorectal polyps also showed as strong an expression of epithelial and variant forms of CD44 as primary and metastatic tumor tissues.


CONCLUSIONS
These results suggest that variant forms of CD44-mRNA might be expressed in an early stage of colorectal carcinogenesis.
Imazeki
F
F
First Department of Medicine, Chiba University School of Medicine, Japan.
Yokosuka
O
O
Yamaguchi
T
T
Ohto
M
M
Isono
K
K
Omata
M
M
D000230:Adenocarcinoma / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D011125:Adenomatous Polyposis Coli / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D015139:Blotting, Southern; D003106:Colon / Q000276:immunology; D015179:Colorectal Neoplasms / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D005260:Female; D014644:Genetic Variation; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics*; D007413:Intestinal Mucosa / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009362:Neoplasm Metastasis; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000378:metabolism*; D014158:Transcription, Genetic
D018960:Hyaluronan Receptors; D012333:RNA, Messenger