ELA/APELA precursor cleaved by furin displays tumor suppressor function in renal cell carcinoma through mTORC1 activation
Fabienne Soulet, Clement Bodineau, Katarzyna B. Hooks, Jean Descarpentrie, Isabel Alves, Marielle Dubreuil, Amandine Mouchard, Malaurie Eugenie, Jean-Luc Hoepffner, Jose J. López, Juan A. Rosado, Isabelle Soubeyran, Mercedes Tomé, Raúl V. Durán, Macha Nikolski, Bruno O. Villoutreix, Serge Evrard, Geraldine Siegfried, Abdel-Majid Khatib
Fabienne Soulet, Clement Bodineau, Katarzyna B. Hooks, Jean Descarpentrie, Isabel Alves, Marielle Dubreuil, Amandine Mouchard, Malaurie Eugenie, Jean-Luc Hoepffner, Jose J. López, Juan A. Rosado, Isabelle Soubeyran, Mercedes Tomé, Raúl V. Durán, Macha Nikolski, Bruno O. Villoutreix, Serge Evrard, Geraldine Siegfried, Abdel-Majid Khatib
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Research Article Nephrology

ELA/APELA precursor cleaved by furin displays tumor suppressor function in renal cell carcinoma through mTORC1 activation

Abstract

Apelin is a well-established mediator of survival and mitogenic signaling through the apelin receptor (Aplnr) and has been implicated in various cancers; however, little is known regarding Elabela (ELA/APELA) signaling, also mediated by Aplnr, and its role and the role of the conversion of its precursor proELA into mature ELA in cancer are unknown. Here, we identified a function of mTORC1 signaling as an essential mediator of ELA that repressed kidney tumor cell growth, migration, and survival. Moreover, sunitinib and ELA showed a synergistic effect in repressing tumor growth and angiogenesis in mice. The use of site-directed mutagenesis and pharmacological experiments provided evidence that the alteration of the cleavage site of proELA by furin induced improved ELA antitumorigenic activity. Finally, a cohort of tumors and public data sets revealed that ELA was only repressed in the main human kidney cancer subtypes, namely clear cell, papillary, and chromophobe renal cell carcinoma. Aplnr was expressed by various kidney cells, whereas ELA was generally expressed by epithelial cells. Collectively, these results showed the tumor-suppressive role of mTORC1 signaling mediated by ELA and established the potential use of ELA or derivatives in kidney cancer treatment.

Authors

Fabienne Soulet, Clement Bodineau, Katarzyna B. Hooks, Jean Descarpentrie, Isabel Alves, Marielle Dubreuil, Amandine Mouchard, Malaurie Eugenie, Jean-Luc Hoepffner, Jose J. López, Juan A. Rosado, Isabelle Soubeyran, Mercedes Tomé, Raúl V. Durán, Macha Nikolski, Bruno O. Villoutreix, Serge Evrard, Geraldine Siegfried, Abdel-Majid Khatib

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Figure 4

Repression of AKT and ERK activation by ELA and inhibition of ELA-induced mTORC1 signaling by rapamycin.

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Repression of AKT and ERK activation by ELA and inhibition of ELA-induce...
(A and B) Western blot analysis of the activation of AKT (A) and ERK (B) in control, ELA-expressing, and mut ELA–expressing cells starved for the indicated time period or in the presence of serum (S). (C and D) Control and Renca cells were serum starved and incubated with ELA11, ELA32, or mut ELA32 peptides for indicated time periods and the activation of AKT (C) and ERK (D) were analyzed by Western blot analysis. (E and F) Western blotting analysis using an anti-ELA antibody of WT proELA32 (E) and mut ELA (F) (cleavage sites R31/R32 and R42/R43 were replaced by S31/S32 and S42/S43) peptides incubated with furin (0.2 × 10−4 U) for 6 or 24 hours. (G) Western blot analysis of cleaved caspase-3 upon rapamycin treatment of control, ELA-expressing, and mut ELA–expressing cells for 24 hours in the absence or presence of serum. Graphs show quantification of cleaved caspase-3. (H and I) Western blot analysis of the activation of S6-pS235/236 (H) and 4EBP1 (I) in control, ELA-expressing, and mut ELA–expressing cells in the absence and presence of rapamycin and/or serum. (J) Western blot analysis of the levels of LC3 in control, ELA-expressing, and mut ELA–expressing cells. Bars denote the corresponding percentages of phosphorylated proteins (n = 3), expressed LC3 protein (n = 3), or cleaved caspase-3 (n = 3). All results shown are representative of at least 3 independent experiments.