Altered post-translational modification of redox factor 1 protein in human uterine smooth muscle tumors.
Uterine leiomyomas are the most common benign smooth muscle tumors in the myometrium. The expression of redox factor 1 (Ref-1), a DNA repair enzyme and redox-modifying factor, was studied in the myometrium and uterine smooth muscle tumors to investigate the relevance of Ref-1 in the growth regulation of the tumors. Two forms of Ref-1 protein were detected, using three antibodies against different epitopes of Ref-1. The abundance of the large form of Ref-1 was increased in leiomyoma extracts relative to myometrial tissue extracts, and the large form was dominant in cell lines derived from leiomyosarcomas. A single mRNA transcript was detected in the same samples, leading us to hypothesize that the differentially migrating forms are the result of posttranslational modification(s). In vitro incubation of leiomyoma tissue extract lead to a shift from the large form to the small form, and this conversion was inhibited by either protease or phosphatase inhibitors. Finally, the relative abundance of the large form of Ref-1 was found to correlate with proliferating cell nuclear antigen levels, suggesting a correlation with increased proliferation. These results indicate that altered posttranslational modification of Ref-1 is involved in uterine smooth muscle tumorigenesis.
Orii
Ayaka
A
Department of Gynecology and Obstetrics, Kyoto University Faculty of Medicine, Kawahara-cho, Shogoin, Kyoto 606-507, Japan.
Masutani
Hiroshi
H
Nikaido
Toshio
T
Zhai
Ya-Li
YL
Kato
Kiyoshi
K
Kariya
Masatoshi
M
Konishi
Ikuo
I
Yodoi
Junji
J
Fujii
Shingo
S
D000328:Adult; D019757:Carbon-Oxygen Lyases / Q000235:genetics* / Q000378:metabolism; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007889:Leiomyoma / Q000503:physiopathology; D007890:Leiomyosarcoma / Q000503:physiopathology; D008875:Middle Aged; D009215:Myometrium / Q000503:physiopathology; D010447:Peptide Hydrolases / Q000378:metabolism; D010766:Phosphorylation; D018809:Proliferating Cell Nuclear Antigen / Q000235:genetics; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000032:analysis; D018235:Smooth Muscle Tumor / Q000503:physiopathology*; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000503:physiopathology*
D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D010447:Peptide Hydrolases; D019757:Carbon-Oxygen Lyases; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase