Differences in the expression of epithelial-mesenchymal transition related molecules between primary tumors and pulmonary metastatic tumors in colorectal cancer.
OBJECTIVE
Epithelial-mesenchymal transition (EMT) is a key event in cancer metastasis. This study immunohistochemically examined the expression of EMT-related molecules in both primary colorectal cancer and pulmonary metastases, and analyzed the expression pattern.


METHODS
Ten patients with colorectal cancer that underwent surgical resections for both the primary tumor and metastatic pulmonary tumors were included. The expression status of EMT-related molecules was examined using immunohistochemical staining.


RESULTS
Nine of the 10 cases maintained the expression of both E-cadherin and β-catenin in the primary site. The expression of E-cadherin and β-catenin in the pulmonary metastatic site was preserved in 10 and 12 out of 15 metastatic lesions, respectively. The EMT-related transcription factor, Twist, was positively expressed in all 10 cases, Smad interacting protein 1 (Sip1) in 9, Snail in 4 and Slug in 3 of the primary sites. On the other hand, staining for Twist, Sip1 and Snail at the metastatic pulmonary site, was negative in all 10 cases.


CONCLUSIONS
The expression of EMT-related transcription factors in metastatic pulmonary tumors from colorectal cancer decreased in comparison to the primary tumors. These findings suggested that the expression status of EMT-related transcription factors might play an important role in the implantation of metastatic foci.
Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Hidenori
H
Kouso
Tokujiro
T
Yano
Riichiroh
R
Maruyama
Yasunori
Y
Shikada
Tatsuro
T
Okamoto
Akira
A
Haro
Yoshihiro
Y
Kakeji
Yoshihiko
Y
Maehara
D000368:Aged; D015820:Cadherins / Q000378:metabolism; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology*; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics* / Q000502:physiology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000473:pathology / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000378:metabolism*; D051879:Twist-Related Protein 1 / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism
D015820:Cadherins; C108381:GEMIN2 protein, human; D009419:Nerve Tissue Proteins; D016601:RNA-Binding Proteins; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D051879:Twist-Related Protein 1; D051176:beta Catenin