1
|
Rapamycin Ameliorates Defects in Mitochondrial Fission and Mitophagy in Glioblastoma Cells. Int J Mol Sci 2021; 22:ijms22105379. [PMID: 34065350 PMCID: PMC8161366 DOI: 10.3390/ijms22105379] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/11/2021] [Accepted: 05/18/2021] [Indexed: 01/18/2023] Open
Abstract
Glioblastoma (GBM) cells feature mitochondrial alterations, which are documented and quantified in the present study, by using ultrastructural morphometry. Mitochondrial impairment, which roughly occurs in half of the organelles, is shown to be related to mTOR overexpression and autophagy suppression. The novelty of the present study consists of detailing an mTOR-dependent mitophagy occlusion, along with suppression of mitochondrial fission. These phenomena contribute to explain the increase in altered mitochondria reported here. Administration of the mTOR inhibitor rapamycin rescues mitochondrial alterations. In detail, rapamycin induces the expression of genes promoting mitophagy (PINK1, PARKIN, ULK1, AMBRA1) and mitochondrial fission (FIS1, DRP1). This occurs along with over-expression of VPS34, an early gene placed upstream in the autophagy pathway. The topographic stoichiometry of proteins coded by these genes within mitochondria indicates that, a remarkable polarization of proteins involved in fission and mitophagy within mitochondria including LC3 takes place. Co-localization of these proteins within mitochondria, persists for weeks following rapamycin, which produces long-lasting mitochondrial plasticity. Thus, rapamycin restores mitochondrial status in GBM cells. These findings add novel evidence about mitochondria and GBM, while fostering a novel therapeutic approach to restore healthy mitochondria through mTOR inhibition.
Collapse
|
2
|
Oushy S, Hellwinkel JE, Wang M, Nguyen GJ, Gunaydin D, Harland TA, Anchordoquy TJ, Graner MW. Glioblastoma multiforme-derived extracellular vesicles drive normal astrocytes towards a tumour-enhancing phenotype. Philos Trans R Soc Lond B Biol Sci 2018; 373:rstb.2016.0477. [PMID: 29158308 DOI: 10.1098/rstb.2016.0477] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/04/2017] [Indexed: 02/07/2023] Open
Abstract
Glioblastoma multiforme (GBM) is a devastating tumour with abysmal prognoses. We desperately need novel approaches to understand GBM biology and therapeutic vulnerabilities. Extracellular vesicles (EVs) are membrane-enclosed nanospheres released locally and systemically by all cells, including tumours, with tremendous potential for intercellular communication. Tumour EVs manipulate their local environments as well as distal targets; EVs may be a mechanism for tumourigenesis in the recurrent GBM setting. We hypothesized that GBM EVs drive molecular changes in normal human astrocytes (NHAs), yielding phenotypically tumour-promoting, or even tumourigenic, entities. We incubated NHAs with GBM EVs and examined the astrocytes for changes in cell migration, cytokine release and tumour cell growth promotion via the conditioned media. We measured alterations in intracellular signalling and transformation capacity (astrocyte growth in soft agar). GBM EV-treated NHAs displayed increased migratory capacity, along with enhanced cytokine production which promoted tumour cell growth. GBM EV-treated NHAs developed tumour-like signalling patterns and exhibited colony formation in soft agar, reminiscent of tumour cells themselves. GBM EVs modify the local environment to benefit the tumour itself, co-opting neighbouring astrocytes to promote tumour growth, and perhaps even driving astrocytes to a tumourigenic phenotype. Such biological activities could have profound impacts in the recurrent GBM setting.This article is part of the discussion meeting issue 'Extracellular vesicles and the tumour microenvironment'.
Collapse
Affiliation(s)
- Soliman Oushy
- University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA.,Department of Neurosurgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Justin E Hellwinkel
- University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA.,Department of Neurosurgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Mary Wang
- Department of Neurosurgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Ger J Nguyen
- Department of Neurosurgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Dicle Gunaydin
- Department of Neurosurgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Tessa A Harland
- University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO 80045, USA.,Department of Neurosurgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Thomas J Anchordoquy
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Michael W Graner
- Department of Neurosurgery, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| |
Collapse
|
3
|
Graner AN, Hellwinkel JE, Lencioni AM, Madsen HJ, Harland TA, Marchando P, Nguyen GJ, Wang M, Russell LM, Bemis LT, Anchordoquy TJ, Graner MW. HSP90 inhibitors in the context of heat shock and the unfolded protein response: effects on a primary canine pulmonary adenocarcinoma cell line. Int J Hyperthermia 2016; 33:303-317. [PMID: 27829290 DOI: 10.1080/02656736.2016.1256503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Agents targeting HSP90 and GRP94 are seldom tested in stressed contexts such as heat shock (HS) or the unfolded protein response (UPR). Tumor stress often activates HSPs and the UPR as pro-survival mechanisms. This begs the question of stress effects on chemotherapeutic efficacy, particularly with drugs targeting chaperones such as HSP90 or GRP94. We tested the utility of several HSP90 inhibitors, including PU-H71 (targeting GRP94), on a primary canine lung cancer line under HS/UPR stress compared to control conditions. METHODS We cultured canine bronchoalveolar adenocarcinoma cells that showed high endogenous HSP90 and GRP94 expression; these levels substantially increased upon HS or UPR induction. We treated cells with HSP90 inhibitors 17-DMAG, 17-AAG or PU-H71 under standard conditions, HS or UPR. Cell viability/survival was assayed. Antibody arrays measured intracellular signalling and apoptosis profiles. RESULTS HS and UPR had varying effects on cells treated with different HSP90 inhibitors; in particular, HS and UPR promoted resistance to inhibitors in short-term assays, but combinations of UPR stress and PU-H571 showed potent cytotoxic activity in longer-term assays. Array data indicated altered signalling pathways, with apoptotic and pro-survival implications. UPR induction + dual targeting of HSP90 and GRP94 swayed the balance toward apoptosis. CONCLUSION Cellular stresses, endemic to tumors, or interventionally inducible, can deflect or enhance chemo-efficacy, particularly with chaperone-targeting drugs. Stress is likely not held accountable when testing new pharmacologics or assessing currently-used drugs. A better understanding of stress impacts on drug activities should be critical in improving therapeutic targeting and in discerning mechanisms of drug resistance.
Collapse
Affiliation(s)
- Arin N Graner
- a Department of Neurosurgery , University of Colorado Denver , Aurora , CO , USA
| | - Justin E Hellwinkel
- a Department of Neurosurgery , University of Colorado Denver , Aurora , CO , USA.,b School of Medicine , University of Colorado School of Medicine , Aurora , CO , USA
| | - Alex M Lencioni
- a Department of Neurosurgery , University of Colorado Denver , Aurora , CO , USA.,c University of Arkansas for Medical Sciences , Little Rock , AR , USA
| | - Helen J Madsen
- a Department of Neurosurgery , University of Colorado Denver , Aurora , CO , USA.,b School of Medicine , University of Colorado School of Medicine , Aurora , CO , USA
| | - Tessa A Harland
- a Department of Neurosurgery , University of Colorado Denver , Aurora , CO , USA.,b School of Medicine , University of Colorado School of Medicine , Aurora , CO , USA
| | - Paul Marchando
- d Department of Chemical and Biological Engineering , University of Colorado Boulder , Boulder , CO , USA
| | - Ger J Nguyen
- a Department of Neurosurgery , University of Colorado Denver , Aurora , CO , USA
| | - Mary Wang
- a Department of Neurosurgery , University of Colorado Denver , Aurora , CO , USA
| | - Laura M Russell
- a Department of Neurosurgery , University of Colorado Denver , Aurora , CO , USA
| | - Lynne T Bemis
- e Department of Biomedical Sciences , University of Minnesota , Duluth , MN , USA
| | - Thomas J Anchordoquy
- f Skaggs School of Pharmacy and Pharmaceutical Sciences , University of Colorado Denver , Aurora , CO , USA
| | - Michael W Graner
- a Department of Neurosurgery , University of Colorado Denver , Aurora , CO , USA
| |
Collapse
|