AKT1E17K Is Oncogenic in Mouse Lung and Cooperates with Chemical Carcinogens in Inducing Lung Cancer

Malanga, Donatella; Belmonte, Stefania; Colelli, Fabiana; Scarfò, Marzia; Marco, Carmela De; Oliveira, Duarte Mendes; Mirante, Teresa; Camastra, Caterina; Gagliardi, Monica; Rizzuto, Antonia; Mignogna, Chiara; Paciello, Orlando; Papparella, Serenella; Fagman, Henrik; Viglietto, Giuseppe

doi:10.1371/journal.pone.0147334

Cited by 11 publications

(11 citation statements)

References 66 publications

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“…To determine the role of miRNAs in lung cancer driven by aberrant PI3K/AKT signaling, we have examined changes in miRNA levels that are induced by alterations of this pathway through different mutations that are observed in human NSCLC [ 11 ], including a gain-of-function mutant of PIK3CA (E545K), a gain-of-function mutant of AKT1 (E17K) and the loss of PTEN expression [ 12 , 13 , 45 , 46 ]. Here we report that miR-196a is modulated by mutant PI3K, mutant AKT1 and by loss of PTEN, and represent a pivotal mediator of proliferation, migration/invasion and tumorigenicity elicited by aberrant activation of PI3K/AKT pathway.…”

Section: Introductionmentioning

confidence: 99%

Analysis of miRNA profiles identified miR-196a as a crucial mediator of aberrant PI3K/AKT signaling in lung cancer cells

et al. 2016

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Hyperactivation of the PI3K/AKT pathway is observed in most human cancer including lung carcinomas. Here we have investigated the role of miRNAs as downstream targets of activated PI3K/AKT signaling in Non Small Cell Lung Cancer (NSCLC). To this aim, miRNA profiling was performed in human lung epithelial cells (BEAS-2B) expressing active AKT1 (BEAS-AKT1-E17K), active PI3KCA (BEAS-PIK3CA-E545K) or with silenced PTEN (BEAS-shPTEN).Twenty-four differentially expressed miRNAs common to BEAS-AKT1-E17K, BEAS-PIK3CA-E545K and BEAS-shPTEN cells were identified through this analysis, with miR-196a being the most consistently up-regulated miRNA. Interestingly, miR-196a was significantly overexpressed also in human NSCLC-derived cell lines (n=11) and primary lung cancer samples (n=28).By manipulating the expression of miR-196a in BEAS-2B and NCI-H460 cells, we obtained compelling evidence that this miRNA acts downstream the PI3K/AKT pathway, mediating some of the proliferative, pro-migratory and tumorigenic activity that this pathway exerts in lung epithelial cells, possibly through the regulation of FoxO1, CDKN1B (hereafter p27) and HOXA9.

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Section: Introductionmentioning

confidence: 99%

Analysis of miRNA profiles identified miR-196a as a crucial mediator of aberrant PI3K/AKT signaling in lung cancer cells

et al. 2016

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“…The phosphatidylinositol 3-kinase (PI3K) signaling cascade plays a critical role in the initiation and/or progression of NSCLC [ 5 – 11 ]. This pathway regulates multiple cellular processes that are relevant in the growth and progression of lung cancer cells including cell proliferation, migration, apoptosis and angiogenesis [ 12 ].…”

Section: Introductionmentioning

confidence: 99%

Specific gene expression signatures induced by the multiple oncogenic alterations that occur within the PTEN/PI3K/AKT pathway in lung cancer

et al. 2017

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Hyperactivation of the phosphatydil-inositol-3' phosphate kinase (PI3K)/AKT pathway is observed in most NSCLCs, promoting proliferation, migration, invasion and resistance to therapy. AKT can be activated through several mechanisms that include loss of the negative regulator PTEN, activating mutations of the catalytic subunit of PI3K (PIK3CA) and/or mutations of AKT1 itself. However, number and identity of downstream targets of activated PI3K/AKT pathway are poorly defined. To identify the genes that are targets of constitutive PI3K/AKT signalling in lung cancer cells, we performed a comparative transcriptomic analysis of human lung epithelial cells (BEAS-2B) expressing active mutant AKT1 (AKT1-E17K), active mutant PIK3CA (PIK3CA-E545K) or that are silenced for PTEN. We found that, altogether, aberrant PI3K/AKT signalling in lung epithelial cells regulated the expression of 1,960/20,436 genes (9%), though only 30 differentially expressed genes (DEGs) (15 up-regulated, 12 down-regulated and 3 discordant) out of 20,436 that were common among BEAS-AKT1-E17K, BEAS-PIK3CA-E545K and BEAS-shPTEN cells (0.1%). Conversely, DEGs specific for mutant AKT1 were 133 (85 up-regulated; 48 down-regulated), DEGs specific for mutant PIK3CA were 502 (280 up-regulated; 222 down-regulated) and DEGs specific for PTEN loss were 1549 (799 up-regulated, 750 down-regulated). The results obtained from array analysis were confirmed by quantitative RT-PCR on selected up- and down-regulated genes (n = 10). Treatment of BEAS-C cells and the corresponding derivatives with pharmacological inhibitors of AKT (MK2206) or PI3K (LY294002) further validated the significance of our findings. Moreover, mRNA expression of selected DEGs (SGK1, IGFBP3, PEG10, GDF15, PTGES, S100P, respectively) correlated with the activation status of the PI3K/AKT pathway assessed by S473 phosphorylation in NSCLC cell lines (n = 6). Finally, we made use of Ingenuity Pathway Analysis (IPA) to investigate the relevant BioFunctions enriched by the costitutive activation of AKT1-, PI3K- or PTEN-dependent signalling in lung epithelial cells. Expectedly, the analysis of the DEGs common to all three alterations highlighted a group of BioFunctions that included Cell Proliferation of tumor cell lines (14 DEGs), Invasion of cells (10 DEGs) and Migration of tumour cell lines (10 DEGs), with a common core of 5 genes (ATF3, CDKN1A, GDF15, HBEGF and LCN2) that likely represent downstream effectors of the pro-oncogenic activities of PI3K/AKT signalling. Conversely, IPA analysis of exclusive DEGs led to the identification of different downstream effectors that are modulated by mutant AKT1 (TGFBR2, CTSZ, EMP1), mutant PIK3CA (CCND2, CDK2, IGFBP2, TRIB1) and PTEN loss (ASNS, FHL2).These findings not only shed light on the molecular mechanisms that are activated by aberrant signalling through the PI3K/AKT pathway in lung epithelial cells, but also contribute to the identification of previously unrecognised molecules whose regulation takes part in the development of lung cancer.

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“…Interestingly, despite the highly common oncogenic and hyperSUMOylated E17K mutant [ 42 , 59 , 60 ] produced a greater induction of the reporter construct than the wt version, the induction of the endogenous Nanog protein produced by both SUMOylatable versions was similar. These results suggest that an unknown regulatory mechanism may impede the overexpression of Nanog in pluripotent stem cells.…”

Section: Discussionmentioning

confidence: 99%

“…Finally, the abrogation of the induction exerted by the SUMOylatable Akt1 variants through co-transfection of a dominant-negative of Ubc9 reveals the role of Akt SUMOylation on Nanog promoter activity in ES cells. Interestingly, despite the highly common oncogenic and hyperSUMOylated E17K mutant [42,59,60] produced a greater induction of the reporter construct than the wt version, the induction of the endogenous Nanog protein produced by both SUMOylatable versions was similar. These results suggest that an unknown regulatory mechanism may impede the overexpression of Nanog in pluripotent stem cells.…”

Section: Plos Onementioning

confidence: 93%

SUMO conjugation susceptibility of Akt/protein kinase B affects the expression of the pluripotency transcription factor Nanog in embryonic stem cells

et al. 2021

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Akt/PKB is a kinase involved in the regulation of a wide variety of cell processes. Its activity is modulated by diverse post-translational modifications (PTMs). Particularly, conjugation of the small ubiquitin-related modifier (SUMO) to this kinase impacts on multiple cellular functions, such as proliferation and splicing. In embryonic stem (ES) cells, this kinase is key for pluripotency maintenance. Among other functions, Akt is known to promote the expression of Nanog, a central pluripotency transcription factor (TF). However, the relevance of this specific PTM of Akt has not been previously analyzed in this context. In this work, we study the effect of Akt1 variants with differential SUMOylation susceptibility on the expression of Nanog. Our results demonstrate that both, the Akt1 capability of being modified by SUMO conjugation and a functional SUMO conjugase activity are required to induce Nanog gene expression. Likewise, we found that the common oncogenic E17K Akt1 mutant affected Nanog expression in ES cells also in a SUMOylatability dependent manner. Interestingly, this outcome takes places in ES cells but not in a non-pluripotent heterologous system, suggesting the presence of a crucial factor for this induction in ES cells. Remarkably, the two major candidate factors to mediate this induction, GSK3-β and Tbx3, are non-essential players of this effect, suggesting a complex mechanism probably involving non-canonical pathways. Furthermore, we found that Akt1 subcellular distribution does not depend on its SUMOylatability, indicating that Akt localization has no influence on the effect on Nanog, and that besides the membrane localization of E17K Akt mutant, SUMOylation is also required for its hyperactivity. Our results highlight the impact of SUMO conjugation in the function of a kinase relevant for a plethora of cellular processes, including the control of a key pluripotency TF.

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AKT1E17K Is Oncogenic in Mouse Lung and Cooperates with Chemical Carcinogens in Inducing Lung Cancer

Cited by 11 publications

References 66 publications

Analysis of miRNA profiles identified miR-196a as a crucial mediator of aberrant PI3K/AKT signaling in lung cancer cells

Analysis of miRNA profiles identified miR-196a as a crucial mediator of aberrant PI3K/AKT signaling in lung cancer cells

Specific gene expression signatures induced by the multiple oncogenic alterations that occur within the PTEN/PI3K/AKT pathway in lung cancer

SUMO conjugation susceptibility of Akt/protein kinase B affects the expression of the pluripotency transcription factor Nanog in embryonic stem cells

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