TTYH2, a human homologue of the Drosophila melanogaster gene tweety, is up-regulated in colon carcinoma and involved in cell proliferation and cell aggregation.
OBJECTIVE
To investigate the expression patterns of TTYH2 in the human colon cancer and colon cancer cell lines and to evaluate the inhibitory effect of small interfering RNA (siRNA) on the expression of TTYH2 in colon cancer cell lines.


METHODS
We investigated the expression patterns of TTYH2 in colon cancer, adjacent non-tumorous colon mucosa, and cancer cell lines (DLD-1, caco-2, and Lovo) by RT-PCR. Furthermore, a siRNA plasmid expression vector against TTYH2 was constructed and transfected into DLD-1 and Caco-2 with Lipofectamine 2000. The down regulation of TTYH2 expression was detected by RT-PCR and the role of siRNA in inducing cell proliferation and cell aggregation was evaluated by MTT and aggregation assay.


RESULTS
TTYH2 gene expression in colon cancer tissue was significantly up-regulated compared with normal colonic mucosa (1.23 +/- 0.404 vs 0.655 +/- 0.373, P = 0.0103). Colon cancer derived cell lines including DLD-1, Caco-2, and Lovo also expressed high levels of TTYH2. In contrast, transfection with siRNA-TTYH2 significantly inhibited both proliferation and scattering of these cancer cell lines.


CONCLUSIONS
The present work demonstrates, for the first time, that the TTYH2 gene expression is significantly up-regulated in colon cancer. The TTYH2 gene may play an important role in regulating both proliferating and metastatic potentials of colorectal cancer.
Toiyama
Yuji
Y
Department of Gastrointestinal and Pediatric Surgery, Division of Reparative Medicine, Institute of Life Sciences, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan.
Mizoguchi
Akira
A
Kimura
Kazushi
K
Hiro
Junichirou
J
Inoue
Yasuhiro
Y
Tutumi
Tomonari
T
Miki
Chikao
C
Kusunoki
Masato
M
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000818:Animals; D018938:Caco-2 Cells; D016022:Case-Control Studies; D002449:Cell Aggregation / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003106:Colon / Q000166:cytology / Q000473:pathology; D003110:Colonic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D004331:Drosophila melanogaster; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000473:pathology; D008565:Membrane Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000494:pharmacology; D014162:Transfection; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics*
D008565:Membrane Proteins; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; C438967:TTYH2 protein, human