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Stabilization of LKB1 and Akt by neddylation regulates energy metabolism in liver cancer.

Barbier-Torres L, Delgado TC, García-Rodríguez JL, Zubiete-Franco I, Fernández-Ramos D, Buqué X, Cano A, Gutiérrez-de Juan V, Fernández-Domínguez I, Lopitz-Otsoa F, Fernández-Tussy P, Boix L, Bruix J, Villa E, Castro A, Lu SC, Aspichueta P, Xirodimas D, Varela-Rey M, Mato JM, Beraza N, Martínez-Chantar ML - Oncotarget (2015)

Bottom Line: Tumor cell death in vivo translating into liver tumor regression was associated with augmented phosphatidylcholine synthesis by the PEMT pathway, known as a liver-specific tumor suppressor, and restored mitochondrial function and TCA cycle flux.Otherwise, in protumoral hepatocytes, neddylation inhibition resulted in metabolic reprogramming rendering a decrease in oxidative phosphorylation and concomitant tumor cell apoptosis.Importantly, we show that neddylation-induced metabolic reprogramming and apoptosis were dependent on LKB1 and Akt stabilization.

View Article: PubMed Central - PubMed

Affiliation: CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Bizkaia Science and Technology Park, Derio, Bizkaia, Spain.

ABSTRACT
The current view of cancer progression highlights that cancer cells must undergo through a post-translational regulation and metabolic reprogramming to progress in an unfriendly environment. In here, the importance of neddylation modification in liver cancer was investigated. We found that hepatic neddylation was specifically enriched in liver cancer patients with bad prognosis. In addition, the treatment with the neddylation inhibitor MLN4924 in Phb1-KO mice, an animal model of hepatocellular carcinoma showing elevated neddylation, reverted the malignant phenotype. Tumor cell death in vivo translating into liver tumor regression was associated with augmented phosphatidylcholine synthesis by the PEMT pathway, known as a liver-specific tumor suppressor, and restored mitochondrial function and TCA cycle flux. Otherwise, in protumoral hepatocytes, neddylation inhibition resulted in metabolic reprogramming rendering a decrease in oxidative phosphorylation and concomitant tumor cell apoptosis. Moreover, Akt and LKB1, hallmarks of proliferative metabolism, were altered in liver cancer being new targets of neddylation. Importantly, we show that neddylation-induced metabolic reprogramming and apoptosis were dependent on LKB1 and Akt stabilization. Overall, our results implicate neddylation/signaling/metabolism, partly mediated by LKB1 and Akt, in the development of liver cancer, paving the way for novel therapeutic approaches targeting neddylation in hepatocellular carcinoma.

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LKB1 and Akt stabilization play an important role on neddylation-induced metabolic disruptions in liver cancer(A) Western blot analysis against Nedd8, LKB1 and Akt in Phb1-KO hepatocytes overexpressing Akt and LKB1 after 48 hours of MLN4924 treatment. (B) Basal oxygen consumption rate (OCR) and (C) extracellular acidification rate (ECAR) values in Phb1-KO hepatocytes after LKB1 and Akt overexpression and silencing. (D) OCR and ECAR were measured in Phb1-KO hepatocytes overexpressing LKB1 and Akt after 48 hours of MLN4924 treatment. The energetic response in cells was measured in the presence of oligomycin, FCCP and rotenone. (E) Caspase-3 activity in Phb1-KO hepatocytes overexpressing LKB1 and Akt after 48 hours of MLN4924 treatment. Values are mean ± SEM. *p<0.5, ***p<0.001 (LKB1/Akt overexpression and silencing vs control).
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Figure 7: LKB1 and Akt stabilization play an important role on neddylation-induced metabolic disruptions in liver cancer(A) Western blot analysis against Nedd8, LKB1 and Akt in Phb1-KO hepatocytes overexpressing Akt and LKB1 after 48 hours of MLN4924 treatment. (B) Basal oxygen consumption rate (OCR) and (C) extracellular acidification rate (ECAR) values in Phb1-KO hepatocytes after LKB1 and Akt overexpression and silencing. (D) OCR and ECAR were measured in Phb1-KO hepatocytes overexpressing LKB1 and Akt after 48 hours of MLN4924 treatment. The energetic response in cells was measured in the presence of oligomycin, FCCP and rotenone. (E) Caspase-3 activity in Phb1-KO hepatocytes overexpressing LKB1 and Akt after 48 hours of MLN4924 treatment. Values are mean ± SEM. *p<0.5, ***p<0.001 (LKB1/Akt overexpression and silencing vs control).

Mentions: To investigate whether the neddylation inhibition induced-apoptosis in Phb1-KO isolated hepatocytes was partially mediated by the decrease in LKB1 and Akt protein stabilization, we overexpressed these two kinases under MLN4924 treatment (Fig. 7A). Overexpression of both LKB1 and Akt per se accounts for increased OCR and ECAR thereby promoting a more proliferative phenotype in these premalignant hepatocytes (Fig 7B-C). On the other hand, LKB1 and Akt silencing (Suppl. Fig. 4D) was associated with decreased OCR and ECAR (Fig. 7B-C). Moreover, MLN4924 treatment under LKB1 and Akt-overexpression did not significantly alter OCR and ECAR levels (Fig 7D). Interestingly, boosting the levels of both LKB1 and Akt was sufficient to counteract the apoptotic response mediated by neddylation inhibition (Fig 7E).


Stabilization of LKB1 and Akt by neddylation regulates energy metabolism in liver cancer.

Barbier-Torres L, Delgado TC, García-Rodríguez JL, Zubiete-Franco I, Fernández-Ramos D, Buqué X, Cano A, Gutiérrez-de Juan V, Fernández-Domínguez I, Lopitz-Otsoa F, Fernández-Tussy P, Boix L, Bruix J, Villa E, Castro A, Lu SC, Aspichueta P, Xirodimas D, Varela-Rey M, Mato JM, Beraza N, Martínez-Chantar ML - Oncotarget (2015)

LKB1 and Akt stabilization play an important role on neddylation-induced metabolic disruptions in liver cancer(A) Western blot analysis against Nedd8, LKB1 and Akt in Phb1-KO hepatocytes overexpressing Akt and LKB1 after 48 hours of MLN4924 treatment. (B) Basal oxygen consumption rate (OCR) and (C) extracellular acidification rate (ECAR) values in Phb1-KO hepatocytes after LKB1 and Akt overexpression and silencing. (D) OCR and ECAR were measured in Phb1-KO hepatocytes overexpressing LKB1 and Akt after 48 hours of MLN4924 treatment. The energetic response in cells was measured in the presence of oligomycin, FCCP and rotenone. (E) Caspase-3 activity in Phb1-KO hepatocytes overexpressing LKB1 and Akt after 48 hours of MLN4924 treatment. Values are mean ± SEM. *p<0.5, ***p<0.001 (LKB1/Akt overexpression and silencing vs control).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385867&req=5

Figure 7: LKB1 and Akt stabilization play an important role on neddylation-induced metabolic disruptions in liver cancer(A) Western blot analysis against Nedd8, LKB1 and Akt in Phb1-KO hepatocytes overexpressing Akt and LKB1 after 48 hours of MLN4924 treatment. (B) Basal oxygen consumption rate (OCR) and (C) extracellular acidification rate (ECAR) values in Phb1-KO hepatocytes after LKB1 and Akt overexpression and silencing. (D) OCR and ECAR were measured in Phb1-KO hepatocytes overexpressing LKB1 and Akt after 48 hours of MLN4924 treatment. The energetic response in cells was measured in the presence of oligomycin, FCCP and rotenone. (E) Caspase-3 activity in Phb1-KO hepatocytes overexpressing LKB1 and Akt after 48 hours of MLN4924 treatment. Values are mean ± SEM. *p<0.5, ***p<0.001 (LKB1/Akt overexpression and silencing vs control).
Mentions: To investigate whether the neddylation inhibition induced-apoptosis in Phb1-KO isolated hepatocytes was partially mediated by the decrease in LKB1 and Akt protein stabilization, we overexpressed these two kinases under MLN4924 treatment (Fig. 7A). Overexpression of both LKB1 and Akt per se accounts for increased OCR and ECAR thereby promoting a more proliferative phenotype in these premalignant hepatocytes (Fig 7B-C). On the other hand, LKB1 and Akt silencing (Suppl. Fig. 4D) was associated with decreased OCR and ECAR (Fig. 7B-C). Moreover, MLN4924 treatment under LKB1 and Akt-overexpression did not significantly alter OCR and ECAR levels (Fig 7D). Interestingly, boosting the levels of both LKB1 and Akt was sufficient to counteract the apoptotic response mediated by neddylation inhibition (Fig 7E).

Bottom Line: Tumor cell death in vivo translating into liver tumor regression was associated with augmented phosphatidylcholine synthesis by the PEMT pathway, known as a liver-specific tumor suppressor, and restored mitochondrial function and TCA cycle flux.Otherwise, in protumoral hepatocytes, neddylation inhibition resulted in metabolic reprogramming rendering a decrease in oxidative phosphorylation and concomitant tumor cell apoptosis.Importantly, we show that neddylation-induced metabolic reprogramming and apoptosis were dependent on LKB1 and Akt stabilization.

View Article: PubMed Central - PubMed

Affiliation: CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Bizkaia Science and Technology Park, Derio, Bizkaia, Spain.

ABSTRACT
The current view of cancer progression highlights that cancer cells must undergo through a post-translational regulation and metabolic reprogramming to progress in an unfriendly environment. In here, the importance of neddylation modification in liver cancer was investigated. We found that hepatic neddylation was specifically enriched in liver cancer patients with bad prognosis. In addition, the treatment with the neddylation inhibitor MLN4924 in Phb1-KO mice, an animal model of hepatocellular carcinoma showing elevated neddylation, reverted the malignant phenotype. Tumor cell death in vivo translating into liver tumor regression was associated with augmented phosphatidylcholine synthesis by the PEMT pathway, known as a liver-specific tumor suppressor, and restored mitochondrial function and TCA cycle flux. Otherwise, in protumoral hepatocytes, neddylation inhibition resulted in metabolic reprogramming rendering a decrease in oxidative phosphorylation and concomitant tumor cell apoptosis. Moreover, Akt and LKB1, hallmarks of proliferative metabolism, were altered in liver cancer being new targets of neddylation. Importantly, we show that neddylation-induced metabolic reprogramming and apoptosis were dependent on LKB1 and Akt stabilization. Overall, our results implicate neddylation/signaling/metabolism, partly mediated by LKB1 and Akt, in the development of liver cancer, paving the way for novel therapeutic approaches targeting neddylation in hepatocellular carcinoma.

Show MeSH
Related in: MedlinePlus