Response of non-small cell lung cancer cells to the inhibitors of phosphatidylinositol 3-kinase/Akt- and MAPK kinase 4/c-Jun NH2-terminal kinase pathways: an effective therapeutic strategy for lung cancer.
OBJECTIVE
We previously showed that phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) pathways cooperate to promote non-small cell lung cancer (NSCLC) cell proliferation in vitro. This study was designed to explore whether inhibition of these pathways effectively inhibits NSCLC tumor growth in vivo.


METHODS
The effects of PI3K/Akt inhibitors {LY294002, adenoviruses expressing dominant-negative mutant of the p85alpha adaptor subunit of PI3K (Ad-dnp85alpha), dominant-negative Akt [Ad-HA-Akt(KM)], or PTEN (Ad-PTEN)}, MKK4/c-jun NH2-terminal kinase (JNK) inhibitor [SP600215, adenovirus expressing dominant-negative MKK4, Ad-MKK4(KR)], and their combinations on proliferation and apoptosis in NSCLC cells were tested in vitro and in vivo using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, a flow cytometry-based terminal deoxynucleotidyl transferase-mediated nick-end labeling assay, Western blot and immunohistochemical analyses, and an NSCLC xenograft tumor model.


RESULTS
Ad-dnp85alpha significantly inhibited proliferation of a subset of NSCLC cell lines used in our study. Intratumoral injection of Ad-dnp85alpha induced a significant decrease in the growth of H1299 NSCLC xenograft tumors. Concurrent inhibition of the PI3K/Akt and MKK4/JNK pathways showed enhanced antiproliferative effects on H1299 cells in vitro and in vivo by increasing apoptosis.


CONCLUSIONS
PI3K/Akt and MKK4/JNK pathways cooperate to stimulate NSCLC cell proliferation by maintaining cell survival, suggesting that simultaneously targeting these two pathways might be an effective therapeutic strategy against NSCLC.
Lee
Ho-Young
HY
Department of Thoracic/Head and Neck Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA. hlee@mdanderson.org
Oh
Seung-Hyun
SH
Suh
Young-Ah
YA
Baek
Jin Hyen
JH
Papadimitrakopoulou
Vali
V
Huang
Suyun
S
Hong
Waun Ki
WK
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002460:Cell Line; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D005419:Flavonoids / Q000494:pharmacology; D005434:Flow Cytometry; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D020287:In Situ Nick-End Labeling; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology / Q000627:therapeutic use; D009154:Mutation; D051058:Oncogene Protein v-akt / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D051059:PTEN Phosphohydrolase / Q000235:genetics / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects*; D023041:Xenograft Model Antitumor Assays / Q000379:methods*
D053148:Caspase 3; D020169:Caspases; D002867:Chromones; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007093:Imidazoles; D048031:JNK Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D009025:Morpholines; D051058:Oncogene Protein v-akt; D051059:PTEN Phosphohydrolase; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011725:Pyridines; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; C494929:PTEN protein, human; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one