MEK inhibition of pancreatic carcinoma cells by U0126 and its effect in combination with sulindac.
OBJECTIVE
The MAP kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) pathway is critical for cell growth and survival. In the current study, we examined the effect of inhibiting the MEK-ERK pathway in pancreatic tumor cells with the MEK-specific inhibitor U0126. In addition, we investigated whether the MEK-ERK pathway influenced the response of pancreatic cancer cells to nonsteroidal antiinflammatory drugs (NSAIDs).


METHODS
Cell growth was monitored by a colorimetric proliferation assay and cell counts. Cell cycle analysis was performed using flow cytometry. Apoptosis was measured using a DNA fragmentation ELISA. Protein expression was detected by Western blot.


CONCLUSIONS
Treatment with U0126 dose dependently inhibited the growth of 3 human pancreatic carcinoma cell lines (BxPC-3, PANC-1, and MIA PaCa-2). U0126 treatment resulted in cell-cycle alterations but did not induce apoptosis. Growth inhibitory concentrations of NSAIDs unexpectedly increased ERK phosphorylation in BxPC-3 and MIA PaCa-2 cells. We therefore evaluated the effect of treating pancreatic tumor cells with the combination of the NSAID sulindac and U0126. Treatment with U0126 complemented sulindac-induced growth inhibition in BxPC-3 and PANC-1 cells. The expression of several cell cycle (p21, p27, cyclin D1) and apoptotic (survivin, Bcl-xL) regulatory proteins was altered after U0126 and/or sulindac treatment. Our findings suggest that inhibition of the MEK-ERK signaling pathway may sensitize pancreatic tumor cells to NSAID therapy.
Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA. maxschmi@iupui.edu/myipschn@iupui.edu
Michele T
MT
Yip-Schneider
C Max
CM
Schmidt
D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002070:Butadienes / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology*; D010190:Pancreatic Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology; D010766:Phosphorylation / Q000187:drug effects; D013467:Sulindac / Q000494:pharmacology*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D002070:Butadienes; D018797:Cell Cycle Proteins; D004791:Enzyme Inhibitors; D009570:Nitriles; C113580:U 0126; D013467:Sulindac; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases