Doxorubicin inhibits TGF-beta signaling in human lung carcinoma A549 cells.
Doxorubicin is a DNA-damaging drug, commonly used for treatment of cancer patients. Doxorubicin causes not only cytotoxic and cytostatic effects, but also inhibits metastasis formation, while TGFbeta1 (Transforming Growth Factor-beta1) is a cytokine that is often up-regulated in human cancers and can promote metastasis formation. We have studied the influence of Doxorubicin on TGFbeta signaling in tumor cells. Here we have demonstrated that Doxorubicin inhibited TGFbeta-signaling in human lung adenocarcinoma A549 cells, namely, it blocked TGFbeta1-induced activation of Smad3-responsive CAGA(12)-Luc reporter, but did not affect c-myc-Luc reporter. That effect was observed as early as after 1-3 h of treating these cells with Doxorubicin, while the other drugs cisplatin or methotrexate did not alter activation of CAGA(12)-Luc reporter under the same conditions. Besides, after 1 h action, Doxorubicin abrogated TGFbeta-induced translocation of Smad3-protein from the cytoplasm to the nucleus. Down-regulation of expression of Smad2, Smad3, and Smad4 proteins, and up-regulation of inhibitory Smad7 protein upon Doxorubicin treatment, were found after 12-24 h of Doxorubicin treatment. Phosphorylation of Smad2/3 proteins was also affected by Doxorubicin. Summarizing, we have found that human tumor cells treatment with Doxorubicin resulted in the inhibition of TGFbeta-signaling at both early (1 h) and later (12 h) stages of the drug action. Such inhibition can be a new potential mechanism for Doxorubicin action towards tumor cells.
Filyak
Yevhen
Y
Institute of Cell Biology, Lviv, Ukraine. YevhenFilyak@biochem.lviv.ua
Filyak
Oksana
O
Souchelnytskyi
Serhiy
S
Stoika
Rostyslav
R
D021581:Active Transport, Cell Nucleus; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D004317:Doxorubicin / Q000494:pharmacology*; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000032:analysis; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000032:analysis; D015398:Signal Transduction / Q000187:drug effects*; D051899:Smad2 Protein / Q000378:metabolism; D051900:Smad3 Protein / Q000032:analysis / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors*
D000903:Antibiotics, Antineoplastic; D018125:Receptors, Transforming Growth Factor beta; C497782:SMAD2 protein, human; C497790:SMAD3 protein, human; D051899:Smad2 Protein; D051900:Smad3 Protein; D016212:Transforming Growth Factor beta; D004317:Doxorubicin; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II