Role of TGF-β signaling in uterine carcinosarcoma.
Uterine carcinosarcomas (UCS) are rare (3-4%) but highly aggressive, accounting for a disproportionately high (16.4%) mortality among uterine malignancies. Transforming growth factor beta (TGFβ) is a multifunctional cytokine that regulates important cellular processes including epithelial-mesenchymal transition (EMT). Existence of biphasic elements and a report demonstrating amplification of TGFβ at 19q13.1 prompted us to investigate the role of TGFβ signaling in UCS.Here we demonstrated the components of TGFβ pathway are expressed and functional in UCS. TGFβ-I induced significant Smad2/3 phosphorylation, migration and EMT responses in UCS cell lines which could be attenuated by the TGFβ receptor I (TGFβR-I) or TGFβ receptor I/II (TGFβR-I/II) inhibitor developed by Eli Lilly and company. Importantly, TGFβ-I induced proliferation was c-Myc dependent, likely through activation of cell cycle. c-Myc was induced by nuclear translocation of nuclear factor of activated T cells (NFAT-1) in response to TGFβ-I. Inhibition of NFAT-1 or TGFβR-I blocked c-Myc induction, cell cycle progression and proliferation in UCS. In corroboration, mRNA levels of c-Myc were elevated in recurrent versus the non-recurrent UCS patient samples. Interestingly, in the absence of exogenous TGFβ the TGFβR-I/II inhibitor enhanced proliferation likely through non-Smad pathways. Thus, inhibition of TGFβR-I could be efficacious in treatment of UCS.
Department of Obstetrics and Gynecology, Stephenson Cancer Center, University of Oklahoma Health Science Center, Oklahoma, USA.
Shailendra Kumar Dhar
SK
Dwivedi
Department of Obstetrics and Gynecology, Stephenson Cancer Center, University of Oklahoma Health Science Center, Oklahoma, USA.
Scott D
SD
McMeekin
Department of Obstetrics and Gynecology, Stephenson Cancer Center, University of Oklahoma Health Science Center, Oklahoma, USA.
Katrina
K
Slaughter
Department of Obstetrics and Gynecology, Stephenson Cancer Center, University of Oklahoma Health Science Center, Oklahoma, USA.
Resham
R
Bhattacharya
D002296:Carcinosarcoma / Q000235:genetics*; D002465:Cell Movement; D049109:Cell Proliferation; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D006801:Humans; D015398:Signal Transduction; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000235:genetics*
D016212:Transforming Growth Factor beta
EMT; TGF beta; c-Myc; uterine carcinosarcoma