Expression of S100A6 and S100A4 in matched samples of human colorectal mucosa, primary colorectal adenocarcinomas and liver metastases.
OBJECTIVE
S100A6 and S100A4, two of S100 protein family, have been suggested to be associated with cancer tumorigenesis and metastasis. The aim of this study was to evaluate the expression levels of S100A6 and S100A4 in matched samples of primary human colorectal adenocarcinomas (T), adjacent normal colorectal mucosa (N) and liver metastases (M). This gave us the advantage of directly comparing levels of S100A6 and S100A4 expression within the same genetic background.


METHODS
In matched samples of N, T and M from 10 colorectal adenocarcinoma patients, expressions of S100A6 and S100A4 were studied by Western blot and immunohistochemical analyses using specific antibodies against each protein.


RESULTS
The expression levels of S100A6 were significantly higher in T than in N (p < 0.05), while those of S100A4 showed no difference between T and N. There were no significant differences in the expression levels of S100A6 or S100A4 between M and T. Similar results were obtained by immunohistochemical analysis. Moreover, S100A6 was stained more intensely in invading fronts than in central portions of both T and M.


CONCLUSIONS
The observed differential expression of S100A6 and S100A4 suggests that S100A6, rather than S100A4, is associated with human colorectal adenocarcinoma tumorigenesis and invasion/metastasis.
Komatsu
Keiko
K
Department of Tumor Biochemistry, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan. komatsu@mail.mc.pref.osaka.jp
Murata
Kohei
K
Kameyama
Masao
M
Ayaki
Masako
M
Mukai
Mutsuko
M
Ishiguro
Shingo
S
Miyoshi
Jun
J
Tatsuta
Masaharu
M
Inoue
Masahiro
M
Nakamura
Hiroyuki
H
D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D000368:Aged; D018797:Cell Cycle Proteins; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D003110:Colonic Neoplasms / Q000473:pathology* / Q000601:surgery; D004815:Epidermal Growth Factor / Q000235:genetics*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism*; D008113:Liver Neoplasms / Q000473:pathology* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000473:pathology* / Q000601:surgery; D000075383:S100 Calcium Binding Protein A6; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins / Q000032:analysis / Q000235:genetics*
D018797:Cell Cycle Proteins; D000075383:S100 Calcium Binding Protein A6; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; C055351:S100A6 protein, human; C077591:S100A4 protein, human; D004815:Epidermal Growth Factor