title: OSU03012 activates Erk1/2 and Cdks leading to the accumulation of cells in the S-phase and apoptosis.
abstract: OSU03012, a Celecoxib derivative, has been shown to inhibit proliferation and induce apoptosis in human cancer cell lines. However, its underlying mechanisms are not completely understood. In our study, the relationship between cell cycle inhibition and apoptosis induced by OSU03012 was investigated in human oral cancer cell lines. In the premalignant and malignant cell lines, OSU03012-induced growth inhibition, S-phase arrest, and apoptosis were accompanied by a marked increase in the activity of Erk1/2 and Cdk2/cyclin A. Inhibition of Cdks by roscovitine partially blocked OSU03012-induced growth inhibition and apoptosis. Although the activity of cdc2/cyclin B was reduced, expression of constructively active cdc2AF did not reverse OSU03012-induced S-phase arrest. When Erk1/2 was inhibited by U0126 before addition of OSU03012, growth inhibition and apoptosis induced by OSU03012 were attenuated. The levels of the Cdk2/cyclin A were reduced and cells accumulated in the G(0)/G(1) phase. When cells were allowed to accumulate in S-phase before addition of U0126, apoptosis also was attenuated suggesting that Erk1/2 is required for both progression of cells into the S-phase and apoptosis. Expression of constructively active MEK enhanced OSU03012-induced apoptosis. OSU03012 selectively inhibited the proliferation in premalignant and malignant, but not normal human oral cell lines. In conclusion, we show that OSU03012 has potent anti-proliferative and apoptotic activity against premalignant and malignant human oral cells through activation of Erk1/2, and Cdks. OSU0312 may provide unique opportunities for cancer prevention and sensitization of cancer cells to S-phase modalities.
authors.affiliation: Department of Radiology, College of Medicine, The Ohio State University, Columbus, OH 43210, USA. ding.29@osu.edu
authors.forename: Haiming
authors.initials: H
authors.lastname: Ding
authors.forename: Chunhua
authors.initials: C
authors.lastname: Han
authors.forename: Dongmei
authors.initials: D
authors.lastname: Guo
authors.forename: Dasheng
authors.initials: D
authors.lastname: Wang
authors.forename: Ching-Shih
authors.initials: CS
authors.lastname: Chen
authors.forename: Steven M
authors.initials: SM
authors.lastname: D'Ambrosio
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D018844:Cyclin-Dependent Kinases / Q000187:drug effects / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D048052:Mitogen-Activated Protein Kinase 3 / Q000187:drug effects / Q000378:metabolism*; D009061:Mouth Mucosa / Q000166:cytology / Q000187:drug effects*; D009062:Mouth Neoplasms / Q000188:drug therapy*; D011720:Pyrazoles / Q000494:pharmacology*; D016196:S Phase / Q000187:drug effects*; D013449:Sulfonamides / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; C500894:OSU 03012; D011720:Pyrazoles; D013449:Sulfonamides; D018844:Cyclin-Dependent Kinases; D048052:Mitogen-Activated Protein Kinase 3