Restoration of RUNX3 enhances transforming growth factor-beta-dependent p21 expression in a biliary tract cancer cell line.
RUNX3 is a candidate tumor suppressor gene localized in 1p36, a region commonly inactivated by deletion and methylation in various human tumors. To elucidate the role of RUNX3 in transforming growth factor (TGF)-beta signaling in biliary tract cancer, we transfected Mz-ChA-2 cells, which do not express RUNX3 but have intact TGF-beta type II receptor and SMAD4 genes, with the RUNX3 expression plasmid pcDNA3.1/RUNX3 or with the vector pcDNA3.1 as a control. Four Mz-ChA-2/RUNX3 clones and one control clone were obtained. Although TGF-beta1 only slightly inhibited growth of the control cells, growth inhibition and TGF-beta-dependent G(1) arrest were significantly enhanced in the RUNX3-transfected clones. None of the clones, however, exhibited apoptosis. The slightly increased TGF-beta1-induced p21 expression in the control clone was strongly enhanced in the RUNX3-transfected clones, and was accompanied by augmented decreases in the expression of cyclins D1 and E. When RUNX3 small interfering RNA was added, TGF-beta-dependent induction of p21 was reduced in the RUNX3-transfected clones. Xenografts of the clones in nude mice demonstrated that tumorigenicity was significantly decreased in the RUNX3-transfected clones in inverse proportion to the expression levels of RUNX3. Based on these results, RUNX3 is involved in TGF-beta-induced expression of p21 and the resulting induction of TGF-beta-dependent G(1) arrest.
Hasegawa
Kazunori
K
Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto, 606-8507, Japan.
Yazumi
Shujiro
S
Wada
Manabu
M
Sakurai
Toshiharu
T
Kida
Masaya
M
Yamauchi
Junichi
J
Hisatsune
Hiroshi
H
Tada
Shinsuke
S
Ida
Hiroshi
H
Nakase
Yuenn
Y
Sakakura
Chohei
C
Hagiwara
Akeo
A
Chiba
Tsutomu
T
D001661:Biliary Tract Neoplasms / Q000378:metabolism*; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D050677:Core Binding Factor Alpha 3 Subunit / Q000235:genetics / Q000502:physiology*; D019938:Cyclin D1 / Q000378:metabolism; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
D018797:Cell Cycle Proteins; D050677:Core Binding Factor Alpha 3 Subunit; C499517:FOXO3 protein, human; D000071316:Forkhead Box Protein O3; D051858:Forkhead Transcription Factors; C493729:Runx3 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D019938:Cyclin D1; D016283:Proto-Oncogene Proteins p21(ras)