Enzastaurin inhibits invasion and metastasis in lung cancer by diverse molecules.
BACKGROUND
Enzastaurin (Enz) is a serine/threonine kinase inhibitor blocking protein kinase C (PKC)beta/AKT pathway. However, an ability of this compound to inhibit cancer invasion and metastasis is not yet clearly elucidated.


METHODS
The ability of Enz to inhibit invasion and metastasis, and to target molecules was investigated in non-small cell lung cancer (NSCLC) by RT-PCR validated microarray, Matrigel, and in vivo chorionallantoic membrane (CAM) assays.


RESULTS
Enzastaurin significantly reduced migration, invasion, and in vivo metastasis to lungs and liver (CAM assay) of diverse NSCLC cell lines. Genes promoting cancer progression (u-PAR, VEGFC, and HIF1alpha) and tumour suppression (VHL, RASSF1, and FHIT) of NSCLC were significantly (P<0.05) down- or upregulated after Enz treatment in H460, A549, and H1299 cells, respectively. Luciferase/chromatin immunoprecipitation analysis showed that Enz transcriptionally controls urokinase-type plasminogen activator receptor (u-PAR) expression by promoter inhibition through Sp1, Sp3, and c-Jun(AP-1). Moreover, siRNA knockdown of u-PAR re-sensitised Enz-resistant cells and induced apoptosis, suggesting u-PAR as a marker of Enz resistance.


CONCLUSIONS
This study shows that Enz inhibits migration, invasion, and in vivo metastasis by targeting u-PAR, besides further targeting progression-related and tumour-suppressor genes in NSCLC. Together with u-PAR being a novel putative marker of Enz response, these data encourage molecularly tailored clinical studies on Enz in NSCLC therapy.
Körner
A
A
Department of Experimental Surgery Mannheim/Molecular Oncology of Solid Tumors (German Cancer Research Center-DKFZ-Heidelberg), Mannheim Medical Faculty, Ruprecht-Karls-University Heidelberg, Mannheim 68167, Germany.
Mudduluru
G
G
Manegold
C
C
Allgayer
H
H
D015153:Blotting, Western; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D024202:Electrophoretic Mobility Shift Assay; D004797:Enzyme-Linked Immunosorbent Assay; D055785:Gene Knockdown Techniques; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D008175:Lung Neoplasms / Q000473:pathology; D009361:Neoplasm Invasiveness / Q000517:prevention & control*; D009362:Neoplasm Metastasis / Q000517:prevention & control*; D009693:Nucleic Acid Hybridization; D020133:Reverse Transcriptase Polymerase Chain Reaction
D007211:Indoles; C504878:enzastaurin