Combination treatment with MEK and AKT inhibitors is more effective than each drug alone in human non-small cell lung cancer in vitro and in vivo.

Abstract

AZD6244 and MK2206 are targeted small-molecule drugs that inhibit MEK and AKT respectively. The efficacy of this combination in lung cancer is unknown. Our previous work showed the importance of activated AKT in mediating resistance of non-small cell lung cancer (NSCLC) to AZD6244. Thus we hypothesized that dual inhibition of both downstream MEK and AKT pathways would induce synergistic antitumor activity. In this study, we evaluated the efficacy of AZD6244 and MK2206 individually on a large panel of lung cancer cell lines. Then, we treated 28 human lung cancer cell lines with a combination of AZD6244 and MK2206 at clinically applicable drug molar ratios. The AZD6244-MK2206 combination therapy resulted in a synergistic effect on inhibition of lung cancer cell growth compared to the results of single drug treatment alone. MK2206 enhanced AZD6244-induced Bim overexpression and apoptosis in A549 and H157 cells. When we tested the combination of AZD6244 and MK2206 at ratios of 8∶1, 4∶1, 2∶1, and 1∶8, we found that the synergistic effect of the combination therapy was ratio-dependent. At ratios of 8∶1, 4∶1, and 2∶1, the drug combination consistently demonstrated synergy, whereas decreasing the ratio to 1∶8 resulted in a loss of synergy and produced an additive or antagonistic effect in most cell lines. Furthermore, the AZD6244-MK2206 combination therapy showed synergy in the suppression of A549 and H157 xenograft tumor growth and increased mean animal survival time. The AZD6244-MK2206 combination therapy resulted in effective inhibition of both p-ERK and p-AKT expression in tumor tissue. In addition, a significant increase of apoptosis was detected in tumor tissue from mice treated with AZD6244-MK2206 compared with that from the single agent treated mice. Our study suggests that the combination of AZD6244 and MK2206 has a significant synergistic effect on tumor growth in vitro and in vivo and leads to increased survival rates in mice bearing highly aggressive human lung tumors.

• Authors: Jieru Meng, Bingbing Dai, Bingliang Fang, B Nebiyou Bekele, William G Bornmann, Duoli Sun, Zhenghong Peng, Roy S Herbst, Vassiliki Papadimitrakopoulou, John D Minna, Michael Peyton, Jack A Roth
• Journal: PloS one (PLoS One) Vol. 5 Issue 11 Pg. e14124 (Nov 29 2010) ISSN: 1932-6203 [Electronic] United States
• PMID: 21124782 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• AZD 6244
• Benzimidazoles
• Heterocyclic Compounds, 3-Ring
• MK 2206
• Proto-Oncogene Proteins c-akt
• Mitogen-Activated Protein Kinase Kinases

Topics

• Animals
• Antineoplastic Combined Chemotherapy Protocols (therapeutic use)
• Apoptosis (drug effects)
• Benzimidazoles (administration & dosage, pharmacology)
• Carcinoma, Non-Small-Cell Lung (drug therapy, metabolism, pathology)
• Cell Cycle (drug effects)
• Cell Line, Tumor
• Cell Survival (drug effects)
• Dose-Response Relationship, Drug
• Drug Synergism
• Female
• Heterocyclic Compounds, 3-Ring (administration & dosage, pharmacology)
• Humans
• Lung Neoplasms (drug therapy, metabolism, pathology)
• Mice
• Mice, Inbred BALB C
• Mice, Nude
• Mitogen-Activated Protein Kinase Kinases (antagonists & inhibitors, metabolism)
• Proto-Oncogene Proteins c-akt (antagonists & inhibitors, metabolism)
• Signal Transduction (drug effects)
• Survival Analysis
• Tumor Burden (drug effects)
• Xenograft Model Antitumor Assays