Reduced expression of the claudin-7 gene correlates with venous invasion and liver metastasis in colorectal cancer.
Claudins, members of a large family of adherent junction proteins, regulate the integrity and function of tight junctions and influence tumorigenesis. Studies have suggested that altered levels of different claudins are related to carcinoma-cell invasion and disease progression. This study examined the relationship between the relative expression of claudin genes and clinicopathological factors, especially invasion and metastasis, in patients with colorectal cancer. We studied surgical specimens of cancer tissue and adjacent normal mucosa from 205 patients with untreated colorectal carcinoma. The relative expression levels of claudin-1, -3, -4 and -7 mRNA in cancer and in normal adjacent mucosa were measured by quantitative real-time, reverse-transcription polymerase chain reaction. The relative expression levels of the claudin-1, -3 and -4 genes were higher in cancer than in normal adjacent mucosa, whereas the relative expression of the claudin-7 gene was similar. An analysis of the relationship between the clinicopathological features and gene expression showed that reduced expression of claudin-7 correlated with venous invasion and liver metastasis. There was also a correlation between claudin-3 and -4 gene expression. Our results suggested that a reduced expression of the claudin-7 gene might lead to venous invasion and liver metastasis in colorectal cancer. Reduced expression of the claudin-7 gene may thus be a useful predictor of liver metastasis in patients with colorectal cancer.
Oshima
Takashi
T
Gastroenterological Center, Yokohama City University Medical Center, Kanagawa-ken 232-0024, Japan. ohshimatakashi@yahoo.co.jp
Kunisaki
Chikara
C
Yoshihara
Kazue
K
Yamada
Roppei
R
Yamamoto
Naoto
N
Sato
Tsutomu
T
Makino
Hirochika
H
Yamagishi
Shigeru
S
Nagano
Yasuhiko
Y
Fujii
Shoich
S
Shiozawa
Manabu
M
Akaike
Makoto
M
Wada
Nobuyuki
N
Rino
Yasushi
Y
Masuda
Munetaka
M
Tanaka
Katsuaki
K
Imada
Toshio
T
D000328:Adult; D000368:Aged; D062445:Claudin-1; D062465:Claudin-3; D062506:Claudin-4; D057167:Claudins; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology / Q000556:secondary*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012333:RNA, Messenger / Q000032:analysis; D014680:Veins / Q000473:pathology
C568108:CLDN1 protein, human; C568122:CLDN3 protein, human; C568157:CLDN4 protein, human; C473255:CLDN7 protein, human; D062445:Claudin-1; D062465:Claudin-3; D062506:Claudin-4; D057167:Claudins; D008565:Membrane Proteins; D012333:RNA, Messenger