Alves 2018 MiPschool Tromso E2

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Role for mitochondria on the response of highly proliferative and invasive bladder cancer cells to the combined inhibition of mTOR and SIRT1.

Link: MitoEAGLE

Silva AM, Bernardino RL, Jarak I, de Oliveira P, Silva BM, Pereira JA, Oliveira PF, Alves MG (2018)

Event: MiPschool Tromso-Bergen 2018


Bladder cancer (BC) has a high incidence and recurrence rate. In addition, patients have a poor survival expectancy. Multiple signaling pathways that interact with mitochondria are involved in events related to tumor aggressiveness and growth. Thus, molecular classification and characterization of the tumor is pivotal to predict clinical outcomes, responses to chemotherapy and develop novel treatments. There are several targets towards personalized medicine, including mitochondrial DNA, mitochondrial metabolic enzymes and cellular signaling proteins. Among those, the mammalian target of rapamycin (mTOR) and NAD-dependent deacetylase sirtuin-1 (SIRT1) are known to independently mediate some cancer related features and mitochondria functioning. Herein we aimed to characterize how the activation or inhibition of SIRT1 and/or mTOR modulate the metabolic and bioenergetics profiles of highly proliferative and invasive stage IV BC cells. For that purpose, TCCSUP cells (BC stage IV) were cultured during 24 h in a normal media or supplemented with EX527 (SIRT1 inhibitor); YK-3-237 (SIRT1 activator) and Rapamycin (mTOR inhibitor), as well as in a combined treatment of EX527+Rapamycin. In addition to cytotoxicity and migration tests, we determined the metabolic profile (metabolic fluxes, 1H-NMR), expression of membrane transporters (GLUT3 and MCT1/MCT4, qPCR), mitochondrial potential (JC-1 fluorescence), intact cell respirometry (Clark-type electrode) and mitochondrial copy number (qPCR) of the cells from each experimental group. Our results show that mTOR inhibition alone or in combination with SIRT1 activation decreased cell density in BC cells. In addition, mitochondrial potential of BC cells was repressed after exposure to the combined treatment of mTOR inhibition with SIRT1 activation/inhibition. In parallel with this, BC cells presented mitochondrial proton leak stimulation, with increased acetate consumption and decreased lactate production after the combined treatment with SIRT1/mTOR inhibitors. Interestingly, inhibition of mTOR alone upregulated the levels of transporters such as GLUT3 and MCT4, but there was no direct action on the levels of metabolites transported by these transporters. On the other hand, activation of SIRT1 downregulated the levels of MCT1 but again, it did not affect lactate levels in the extracellular medium. Overall, our results show that the combined inhibition of mTOR and SIRT1 in highly proliferative and invasive BC cells affects mitochondria physiology, which may elicit positive effects on the treatment of bladder cancer. Nevertheless, although our data shows promising results in the response of highly proliferative and invasive BC cells to the combined treatment with combined mTOR and SIRT1 inhibitors, this is a first assessment of the metabolic and bioenergetics profile of these cells. Further studies will be needed to unveil the molecular mechanisms by which mitochondria mediates the positive response of highly proliferative and invasive BC cells to the combined inhibition of mTOR and SIRT1.

Bioblast editor: Plangger M


Silva AM(1), Bernardino RL(1), Jarak I(3), de Oliveira P(1,2), Silva BM(4), Pereira JA(5), Oliveira PF(1,6,7), Alves MG(1)

  1. Unit Multidisciplinary Research Biomedicine, Lab Cell Biol, Dept Microscopy, Inst Biomedical Sciences Abel Salazar, Univ Porto
  2. Dept Biophysics Biomathematics, IBILI-Fac Medicine
  3. Dept Life Sciences, Univ Coimbra
  4. UBI – Fac Health Sciences, Univ Beira Interior, Covilhã
  5. Mountain Research Centre, School Agriculture, Polytechnic Inst Bragança
  6. I3S - Inst Investigação Inovação em Saúde, Porto
  7. Fac Medicine, Univ Porto; Portugal. -


This work was supported by the Portuguese Foundation for Science and Technology: M.G. Alves (IFCT2015 and PTDC/BIM-MET/4712/2014); P.F. Oliveira (IFCT2015 and PTDC/BBB-BQB/1368/2014); UMIB (Pest-OE/SAL/UI02015/2014); co-funded by FEDER funds through the POCI/COMPETE 2020.

Labels: MiParea: Respiration  Pathology: Cancer 

Organism: Human  Tissue;cell: Endothelial;epithelial;mesothelial cell  Preparation: Intact cells 

Event: E2