Abstract
The exact influence of statins on gefitinib resistance in human non-small cell lung cancer (NSCLC) cells with KRAS mutation alone or KRAS/PIK3CA and KRAS/PTEN comutations remains unclear. This work found that transfection of mutant KRAS plasmids significantly suppressed the gefitinib cytotoxicity in Calu3 cells (wild-type KRAS). Gefitinib disrupted the Kras/PI3K and Kras/Raf complexes in Calu3 cells, whereas not in Calu3 KRAS mutant cells. These trends were corresponding to the expression of pAKT and pERK in gefitinib treatment. Atorvastatin (1 μM) plus gefitinib treatment inhibited proliferation, promoted cell apoptosis, and reduced the AKT activity in KRAS mutant NSCLC cells compared with gefitinib alone. Atorvastatin (5 μM) further enhanced the gefitinib cytotoxicity through concomitant inhibition of AKT and ERK activity. Atorvastatin could interrupt Kras/PI3K and Kras/Raf complexes, leading to suppression of AKT and ERK activity. Similar results were also obtained in comutant KRAS/PTEN or KRAS/PIK3CA NSCLC cells. Furthermore, mevalonate administration reversed the effects of atorvastatin on the Kras/Raf and Kras/PI3K complexes, as well as AKT and ERK activity in both A549 and Calu1 cells. The in vivo results were similar to those obtained in vitro. Therefore, mutant KRAS-mediated gefitinib insensitivity is mainly derived from failure to disrupt the Kras/Raf and Kras/PI3K complexes in KRAS mutant NSCLC cells. Atorvastatin overcomes gefitinib resistance in KRAS mutant NSCLC cells irrespective of PIK3CA and PTEN statuses through inhibition of HMG-CoA reductase-dependent disruption of the Kras/Raf and Kras/PI3K complexes.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Antineoplastic Agents / pharmacology
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Antineoplastic Agents / therapeutic use
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Apoptosis / drug effects
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Atorvastatin
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Carcinoma, Non-Small-Cell Lung / drug therapy*
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Carcinoma, Non-Small-Cell Lung / enzymology
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Carcinoma, Non-Small-Cell Lung / genetics
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Carcinoma, Non-Small-Cell Lung / pathology
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Cell Line, Tumor
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Cell Proliferation / drug effects
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Class I Phosphatidylinositol 3-Kinases
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Drug Resistance, Neoplasm / drug effects*
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Drug Synergism
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Extracellular Signal-Regulated MAP Kinases / antagonists & inhibitors
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Extracellular Signal-Regulated MAP Kinases / metabolism
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Gefitinib
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Heptanoic Acids / pharmacology*
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Heptanoic Acids / therapeutic use
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Humans
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Lung Neoplasms / drug therapy*
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Lung Neoplasms / enzymology
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Lung Neoplasms / genetics
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Lung Neoplasms / pathology
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Mice
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Mutation / genetics*
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Phosphatidylinositol 3-Kinases / metabolism
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Phosphoinositide-3 Kinase Inhibitors
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Proto-Oncogene Proteins / genetics*
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Proto-Oncogene Proteins c-akt / antagonists & inhibitors
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Proto-Oncogene Proteins c-akt / metabolism
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Proto-Oncogene Proteins c-raf / metabolism
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Proto-Oncogene Proteins p21(ras)
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Pyrroles / pharmacology*
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Pyrroles / therapeutic use
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Quinazolines / pharmacology*
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Quinazolines / therapeutic use
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Signal Transduction / drug effects
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Xenograft Model Antitumor Assays
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ras Proteins / genetics*
Substances
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Antineoplastic Agents
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Heptanoic Acids
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KRAS protein, human
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Phosphoinositide-3 Kinase Inhibitors
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Proto-Oncogene Proteins
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Pyrroles
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Quinazolines
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Atorvastatin
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Class I Phosphatidylinositol 3-Kinases
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PIK3CA protein, human
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Proto-Oncogene Proteins c-akt
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Proto-Oncogene Proteins c-raf
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Extracellular Signal-Regulated MAP Kinases
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Proto-Oncogene Proteins p21(ras)
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ras Proteins
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Gefitinib