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de Almeida Schirmer BG, de Araujo MR, Silveira MB, Pereira JM, Vieira LC, Alves CG, Mbolela WT, Ferreira AV, Silva-Cunha A, Fialho SL, da Silva JB, Malamut C. Comparison of [ 18F]Fluorocholine and [ 18F]Fluordesoxyglucose for assessment of progression, lung metastasis detection and therapy response in murine 4T1 breast tumor model. Appl Radiat Isot 2018; 140:278-288. [PMID: 30081351 DOI: 10.1016/j.apradiso.2018.07.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/23/2018] [Accepted: 07/25/2018] [Indexed: 10/28/2022]
Abstract
The [18F]Fluorocholine ([18F]FCH) tracer for PET imaging has been proven to be effective for several malignances. However, there are only a few studies related to its breast tumor applicability and they are still limited. The aim of this study was investigate the efficacy of [18F]FCH/PET compared to [18F]FDG/PET in a murine 4T1 mammary carcinoma model treated and nontreated. [18F]FCH/PET showed its applicability for primary tumor and lung metastasis detection and their use for response monitoring of breast cancer therapeutics at earlier stages.
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Affiliation(s)
| | - Marina Rios de Araujo
- Unidade de Pesquisa e Produção de Radiofármacos, Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, Brazil
| | - Marina Bicalho Silveira
- Unidade de Pesquisa e Produção de Radiofármacos, Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, Brazil
| | - Jousie Michel Pereira
- Unidade de Pesquisa e Produção de Radiofármacos, Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, Brazil
| | - Lorena Carla Vieira
- Faculdade de Farmácia - Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil; Fundação Ezequiel Dias (FUNED), Belo Horizonte, Brazil
| | - Clarice Gregório Alves
- Unidade de Pesquisa e Produção de Radiofármacos, Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, Brazil
| | - William Tshisuaka Mbolela
- Unidade de Pesquisa e Produção de Radiofármacos, Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, Brazil
| | - Andrea Vidal Ferreira
- Unidade de Pesquisa e Produção de Radiofármacos, Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, Brazil
| | - Armando Silva-Cunha
- Faculdade de Farmácia - Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Brazil
| | | | - Juliana Batista da Silva
- Unidade de Pesquisa e Produção de Radiofármacos, Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, Brazil
| | - Carlos Malamut
- Unidade de Pesquisa e Produção de Radiofármacos, Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, Brazil.
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Morrison Joly M, Williams MM, Hicks DJ, Jones B, Sanchez V, Young CD, Sarbassov DD, Muller WJ, Brantley-Sieders D, Cook RS. Two distinct mTORC2-dependent pathways converge on Rac1 to drive breast cancer metastasis. Breast Cancer Res 2017; 19:74. [PMID: 28666462 PMCID: PMC5493112 DOI: 10.1186/s13058-017-0868-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 06/14/2017] [Indexed: 02/06/2023] Open
Abstract
Background The importance of the mTOR complex 2 (mTORC2) signaling complex in tumor progression is becoming increasingly recognized. HER2-amplified breast cancers use Rictor/mTORC2 signaling to drive tumor formation, tumor cell survival and resistance to human epidermal growth factor receptor 2 (HER2)-targeted therapy. Cell motility, a key step in the metastatic process, can be activated by mTORC2 in luminal and triple negative breast cancer cell lines, but its role in promoting metastases from HER2-amplified breast cancers is not yet clear. Methods Because Rictor is an obligate cofactor of mTORC2, we genetically engineered Rictor ablation or overexpression in mouse and human HER2-amplified breast cancer models for modulation of mTORC2 activity. Signaling through mTORC2-dependent pathways was also manipulated using pharmacological inhibitors of mTOR, Akt, and Rac. Signaling was assessed by western analysis and biochemical pull-down assays specific for Rac-GTP and for active Rac guanine nucleotide exchange factors (GEFs). Metastases were assessed from spontaneous tumors and from intravenously delivered tumor cells. Motility and invasion of cells was assessed using Matrigel-coated transwell assays. Results We found that Rictor ablation potently impaired, while Rictor overexpression increased, metastasis in spontaneous and intravenously seeded models of HER2-overexpressing breast cancers. Additionally, migration and invasion of HER2-amplified human breast cancer cells was diminished in the absence of Rictor, or upon pharmacological mTOR kinase inhibition. Active Rac1 was required for Rictor-dependent invasion and motility, which rescued invasion/motility in Rictor depleted cells. Rictor/mTORC2-dependent dampening of the endogenous Rac1 inhibitor RhoGDI2, a factor that correlated directly with increased overall survival in HER2-amplified breast cancer patients, promoted Rac1 activity and tumor cell invasion/migration. The mTORC2 substrate Akt did not affect RhoGDI2 dampening, but partially increased Rac1 activity through the Rac-GEF Tiam1, thus partially rescuing cell invasion/motility. The mTORC2 effector protein kinase C (PKC)α did rescue Rictor-mediated RhoGDI2 downregulation, partially rescuing Rac-guanosine triphosphate (GTP) and migration/motility. Conclusion These findings suggest that mTORC2 uses two coordinated pathways to activate cell invasion/motility, both of which converge on Rac1. Akt signaling activates Rac1 through the Rac-GEF Tiam1, while PKC signaling dampens expression of the endogenous Rac1 inhibitor, RhoGDI2. Electronic supplementary material The online version of this article (doi:10.1186/s13058-017-0868-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Meghan Morrison Joly
- Department of Cancer Biology, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Rm 749 Preston Research Building, Nashville, TN, 37232, USA
| | - Michelle M Williams
- Department of Cancer Biology, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Rm 749 Preston Research Building, Nashville, TN, 37232, USA
| | - Donna J Hicks
- Department of Cancer Biology, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Rm 749 Preston Research Building, Nashville, TN, 37232, USA
| | - Bayley Jones
- Department of Cancer Biology, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Rm 749 Preston Research Building, Nashville, TN, 37232, USA
| | - Violeta Sanchez
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Christian D Young
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Dos D Sarbassov
- Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - William J Muller
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Dana Brantley-Sieders
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Rebecca S Cook
- Department of Cancer Biology, Vanderbilt University School of Medicine, 2220 Pierce Avenue, Rm 749 Preston Research Building, Nashville, TN, 37232, USA.
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