Background: Squamous cell lung cancer (SQCLC) represents 30−40% of all non-small-cell lung tumors and, to date, no targeted therapies are clinically available. A prominent role in the pathogenesis and metastasization of SQCLC has been attributed to aberrant activation of the phosphoinositide 3-kinase (PI3K) signaling pathway, due to amplification (25−40%) or oncogenic driver mutations E545K and H1047R of the PIK3CA (3−10%). Deregulation of PI3K/AKT/mTOR pathway is involved in lung tumorigenesis and it has been associated with high grade tumors (G3-G4) and advanced disease (stage III). The aim of this study was to analyse the effect of three inhibitors, NVP-BEZ235, NVP-BKM120 and NVP-BYL719, showing different specificity towards PI3K and mTOR proteins, in SQCLC cell lines harboring p110a subunit amplification or mutations. Material and Methods: SKMES-1 cells were stable transfected with plasmids containing wild type, or mutated E545K or H1047R p110a subunit of PI3K and clones showing high activity of PI3K/AKT/mTOR signalling were selected for further investigation. H596 and HCC2450 cells, carrying E545K and H1047R PI3K point mutation respectively, were also included in the study. Results: The PI3KCA mutated/amplified clones showed an increased growth rate both in 2D and 3D cultures but no increased inhibition of cell proliferation after drug treatments was observed with respect to SKMES-1. Since PI3K axis controls cell motility through the activation of RhoA/Rac1/CDC42 proteins, we analyzed the effect of PI3K inhibitors on the invasive phenotype and epithelial–mesenchymal transition (EMT). PI3KCA mutated/amplified clones showed increased migration and invasion properties associated with increased activity of RhoA, CDC42, Rac1 and MMP 2 and 9 proteins. PI3K inhibitors significantly reduced migration/invasion capability, MPPs production, RhoA family activity and EMT only in cells carrying PI3K gain of function. In vivo experiments confirmed that tumors from PI3K mutated clone retained the mesenchymal phenotype and proved the ability of BYL719 in reducing the expression of vimentin in cytokeratin 7 positive cells, whereas we do not observe differences in the change of tumor volume between xenografts from SKMES-1 and mutated clone after BYL719 treatment. Conclusion: The data presented confirm that the use of specific PI3K inhibitors reverted the invasive phenotype and inhibited the EMT in the presence of PI3K gene alterations.

Targeting PI3K somatic mutations reduces invasion and EMT in squamous cell carcinoma of the lung / Cavazzoni, Andrea; Bonelli, Mara; Saccani, Francesca; Galetti, Maricla; Caffarra, Cristina; Cretella, Daniele; Fumarola, Claudia; Alfieri, Roberta; Petronini, Pier Giorgio. - In: EUROPEAN JOURNAL OF CANCER. - ISSN 0959-8049. - 50:Supplement 6(2014), pp. 129-129.

Targeting PI3K somatic mutations reduces invasion and EMT in squamous cell carcinoma of the lung

CAVAZZONI, Andrea;BONELLI, Mara;SACCANI, Francesca;GALETTI, Maricla;CAFFARRA, Cristina;CRETELLA, DANIELE;FUMAROLA, Claudia;ALFIERI, Roberta;PETRONINI, Pier Giorgio
2014-01-01

Abstract

Background: Squamous cell lung cancer (SQCLC) represents 30−40% of all non-small-cell lung tumors and, to date, no targeted therapies are clinically available. A prominent role in the pathogenesis and metastasization of SQCLC has been attributed to aberrant activation of the phosphoinositide 3-kinase (PI3K) signaling pathway, due to amplification (25−40%) or oncogenic driver mutations E545K and H1047R of the PIK3CA (3−10%). Deregulation of PI3K/AKT/mTOR pathway is involved in lung tumorigenesis and it has been associated with high grade tumors (G3-G4) and advanced disease (stage III). The aim of this study was to analyse the effect of three inhibitors, NVP-BEZ235, NVP-BKM120 and NVP-BYL719, showing different specificity towards PI3K and mTOR proteins, in SQCLC cell lines harboring p110a subunit amplification or mutations. Material and Methods: SKMES-1 cells were stable transfected with plasmids containing wild type, or mutated E545K or H1047R p110a subunit of PI3K and clones showing high activity of PI3K/AKT/mTOR signalling were selected for further investigation. H596 and HCC2450 cells, carrying E545K and H1047R PI3K point mutation respectively, were also included in the study. Results: The PI3KCA mutated/amplified clones showed an increased growth rate both in 2D and 3D cultures but no increased inhibition of cell proliferation after drug treatments was observed with respect to SKMES-1. Since PI3K axis controls cell motility through the activation of RhoA/Rac1/CDC42 proteins, we analyzed the effect of PI3K inhibitors on the invasive phenotype and epithelial–mesenchymal transition (EMT). PI3KCA mutated/amplified clones showed increased migration and invasion properties associated with increased activity of RhoA, CDC42, Rac1 and MMP 2 and 9 proteins. PI3K inhibitors significantly reduced migration/invasion capability, MPPs production, RhoA family activity and EMT only in cells carrying PI3K gain of function. In vivo experiments confirmed that tumors from PI3K mutated clone retained the mesenchymal phenotype and proved the ability of BYL719 in reducing the expression of vimentin in cytokeratin 7 positive cells, whereas we do not observe differences in the change of tumor volume between xenografts from SKMES-1 and mutated clone after BYL719 treatment. Conclusion: The data presented confirm that the use of specific PI3K inhibitors reverted the invasive phenotype and inhibited the EMT in the presence of PI3K gene alterations.
2014
Targeting PI3K somatic mutations reduces invasion and EMT in squamous cell carcinoma of the lung / Cavazzoni, Andrea; Bonelli, Mara; Saccani, Francesca; Galetti, Maricla; Caffarra, Cristina; Cretella, Daniele; Fumarola, Claudia; Alfieri, Roberta; Petronini, Pier Giorgio. - In: EUROPEAN JOURNAL OF CANCER. - ISSN 0959-8049. - 50:Supplement 6(2014), pp. 129-129.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11381/2798099
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