51
|
Williams MM, Lee L, Werfel T, Joly MMM, Hicks DJ, Rahman B, Elion D, McKernan C, Sanchez V, Estrada MV, Massarweh S, Elledge R, Duvall C, Cook RS. Intrinsic apoptotic pathway activation increases response to anti-estrogens in luminal breast cancers. Cell Death Dis 2018; 9:21. [PMID: 29343814 PMCID: PMC5833697 DOI: 10.1038/s41419-017-0072-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Revised: 08/10/2017] [Accepted: 08/17/2017] [Indexed: 01/26/2023]
Abstract
Estrogen receptor-α positive (ERα+) breast cancer accounts for approximately 70–80% of the nearly 25,0000 new cases of breast cancer diagnosed in the US each year. Endocrine-targeted therapies (those that block ERα activity) serve as the first line of treatment in most cases. Despite the proven benefit of endocrine therapies, however, ERα+ breast tumors can develop resistance to endocrine therapy, causing disease progression or relapse, particularly in the metastatic setting. Anti-apoptotic Bcl-2 family proteins enhance breast tumor cell survival, often promoting resistance to targeted therapies, including endocrine therapies. Herein, we investigated whether blockade of anti-apoptotic Bcl-2 family proteins could sensitize luminal breast cancers to anti-estrogen treatment. We used long-term estrogen deprivation (LTED) of human ERα+ breast cancer cell lines, an established model of sustained treatment with and acquired resistance to aromatase inhibitors (AIs), in combination with Bcl-2/Bcl-xL inhibition (ABT-263), finding that ABT-263 induced only limited tumor cell killing in LTED-selected cells in culture and in vivo. Interestingly, expression and activity of the Bcl-2-related factor Mcl-1 was increased in LTED cells. Genetic Mcl-1 ablation induced apoptosis in LTED-selected cells, and potently increased their sensitivity to ABT-263. Increased expression and activity of Mcl-1 was similarly seen in clinical breast tumor specimens treated with AI + the selective estrogen receptor downregulator fulvestrant. Delivery of Mcl-1 siRNA loaded into polymeric nanoparticles (MCL1 si-NPs) decreased Mcl-1 expression in LTED-selected and fulvestrant-treated cells, increasing tumor cell death and blocking tumor cell growth. These findings suggest that Mcl-1 upregulation in response to anti-estrogen treatment enhances tumor cell survival, decreasing response to therapeutic treatments. Therefore, strategies blocking Mcl-1 expression or activity used in combination with endocrine therapies would enhance tumor cell death.
Collapse
|
52
|
Williams MM, Vaught DB, Joly MM, Hicks DJ, Sanchez V, Owens P, Rahman B, Elion DL, Balko JM, Cook RS. ErbB3 drives mammary epithelial survival and differentiation during pregnancy and lactation. Breast Cancer Res 2017; 19:105. [PMID: 28886748 PMCID: PMC5591538 DOI: 10.1186/s13058-017-0893-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 08/07/2017] [Indexed: 01/05/2023] Open
Abstract
Background During pregnancy, as the mammary gland prepares for synthesis and delivery of milk to newborns, a luminal mammary epithelial cell (MEC) subpopulation proliferates rapidly in response to systemic hormonal cues that activate STAT5A. While the receptor tyrosine kinase ErbB4 is required for STAT5A activation in MECs during pregnancy, it is unclear how ErbB3, a heterodimeric partner of ErbB4 and activator of phosphatidyl inositol-3 kinase (PI3K) signaling, contributes to lactogenic expansion of the mammary gland. Methods We assessed mRNA expression levels by expression microarray of mouse mammary glands harvested throughout pregnancy and lactation. To study the role of ErbB3 in mammary gland lactogenesis, we used transgenic mice expressing WAP-driven Cre recombinase to generate a mouse model in which conditional ErbB3 ablation occurred specifically in alveolar mammary epithelial cells (aMECs). Results Profiling of RNA from mouse MECs isolated throughout pregnancy revealed robust Erbb3 induction during mid-to-late pregnancy, a time point when aMECs proliferate rapidly and undergo differentiation to support milk production. Litters nursed by ErbB3KO dams weighed significantly less when compared to litters nursed by ErbB3WT dams. Further analysis revealed substantially reduced epithelial content, decreased aMEC proliferation, and increased aMEC cell death during late pregnancy. Consistent with the potent ability of ErbB3 to activate cell survival through the PI3K/Akt pathway, we found impaired Akt phosphorylation in ErbB3KO samples, as well as impaired expression of STAT5A, a master regulator of lactogenesis. Constitutively active Akt rescued cell survival in ErbB3-depleted aMECs, but failed to restore STAT5A expression or activity. Interestingly, defects in growth and survival of ErbB3KO aMECs as well as Akt phosphorylation, STAT5A activity, and expression of milk-encoding genes observed in ErbB3KO MECs progressively improved between late pregnancy and lactation day 5. We found a compensatory upregulation of ErbB4 activity in ErbB3KO mammary glands. Enforced ErbB4 expression alleviated the consequences of ErbB3 ablation in aMECs, while combined ablation of both ErbB3 and ErbB4 exaggerated the phenotype. Conclusions These studies demonstrate that ErbB3, like ErbB4, enhances lactogenic expansion and differentiation of the mammary gland during pregnancy, through activation of Akt and STAT5A, two targets crucial for lactation. Electronic supplementary material The online version of this article (doi:10.1186/s13058-017-0893-7) contains supplementary material, which is available to authorized users.
Collapse
|
53
|
Giltnane JM, Hutchinson KE, Stricker TP, Formisano L, Young CD, Estrada MV, Nixon MJ, Du L, Sanchez V, Ericsson PG, Kuba MG, Sanders ME, Mu XJ, Van Allen EM, Wagle N, Mayer IA, Abramson V, Gόmez H, Rizzo M, Toy W, Chandarlapaty S, Mayer EL, Christiansen J, Murphy D, Fitzgerald K, Wang K, Ross JS, Miller VA, Stephens PJ, Yelensky R, Garraway L, Shyr Y, Meszoely I, Balko JM, Arteaga CL. Genomic profiling of ER + breast cancers after short-term estrogen suppression reveals alterations associated with endocrine resistance. Sci Transl Med 2017; 9:eaai7993. [PMID: 28794284 PMCID: PMC5723145 DOI: 10.1126/scitranslmed.aai7993] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2016] [Revised: 03/30/2017] [Accepted: 06/29/2017] [Indexed: 12/11/2022]
Abstract
Inhibition of proliferation in estrogen receptor-positive (ER+) breast cancers after short-term antiestrogen therapy correlates with long-term patient outcome. We profiled 155 ER+/human epidermal growth factor receptor 2-negative (HER2-) early breast cancers from 143 patients treated with the aromatase inhibitor letrozole for 10 to 21 days before surgery. Twenty-one percent of tumors remained highly proliferative, suggesting that these tumors harbor alterations associated with intrinsic endocrine therapy resistance. Whole-exome sequencing revealed a correlation between 8p11-12 and 11q13 gene amplifications, including FGFR1 and CCND1, respectively, and high Ki67. We corroborated these findings in a separate cohort of serial pretreatment, postneoadjuvant chemotherapy, and recurrent ER+ tumors. Combined inhibition of FGFR1 and CDK4/6 reversed antiestrogen resistance in ER+FGFR1/CCND1 coamplified CAMA1 breast cancer cells. RNA sequencing of letrozole-treated tumors revealed the existence of intrachromosomal ESR1 fusion transcripts and increased expression of gene signatures indicative of enhanced E2F-mediated transcription and cell cycle processes in cancers with high Ki67. These data suggest that short-term preoperative estrogen deprivation followed by genomic profiling can be used to identify druggable alterations that may cause intrinsic endocrine therapy resistance.
Collapse
|
54
|
Maldonado G, Gruosso D, Valera F, Mosquera V, Sanchez V, Fernandez-Tarrio R, Dominguez F, Garcia-Robles J, Rabasa J, Calvo-Iglesias F, Rodriguez-Palomares J, Evangelista A. P5168Trends in the management of acute Type A aortic intramural haematoma (IMH). Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p5168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
55
|
Maldonado G, Galian L, Carro A, Gallego P, Calvo-Iglesias F, Bermejo J, Robledo-Carmona J, Sanchez V, Saura D, Arnold R, Teixido G, Granato C, Gutierrez L, Rodriguez-Palomares J, Evangelista A. P6314Echocardiography screening of first degree relatives of bicuspid aortic valve. Heritability and performance evaluation. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p6314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
56
|
Maldonado G, Galian L, Gallego P, Calvo F, Bermejo J, Robledo-Carmona J, Sanchez V, Saura D, Arnold R, Teixido G, Villalva N, Granato C, Gutierrez L, Rodriguez-Palomares J, Evangelista A. P5176Aortic dilation heterogeneity in bicuspid aortic valve patients. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p5176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
57
|
Lee KM, Giltnane J, Balko J, Schwarz L, Guerrero A, Hutchinson K, Hicks M, Sanchez V, Sanders M, Lee T, Olejniczak E, Fesik S, Arteaga C. Abstract 3890: Mitochondrial MCL1 maintains triple negative breast cancer stem cells and contributes to chemotherapy resistance. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-3890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Cytotoxic chemotherapy is the standard of care for patients with triple negative breast cancer (TNBC). Most patients with advanced TNBC progress after chemotherapy and die from metastatic disease. MCL1 is an anti-apoptotic Bcl-2 family member known to sequester and inactivate pro-apoptotic Bcl-2 family proteins and, thus, contribute to chemotherapy resistance. We previously reported that ~45% of residual TNBCs that remain in the breast after neoadjuvant chemotherapy harbor MCL1 amplification, suggesting a causal role for MCL1 in drug resistance. A recent report (Goodwin et al. 2015) suggested that siRNA-mediated ablation of MCL1 does not induce apoptosis in claudin-low TNBC cells with a cancer stem cell (CSC) gene expression signature. CSCs comprise a rare population of cells with tumor-initiating properties and refractoriness to chemotherapy. In this study, we showed that MCL1 expression is elevated in claudin-low TNBC SUM159PT and MDA436 CSCs as measured by ALDH+ by flow cytometry and ability to form mammospheres. RNA interference of MCL1 in SUM159PT cells reduced CSCs and attenuated tumor formation in vivo. Mitochondrial oxidative phosphorylation (mtOXPHOS) plays a crucial role in maintenance of CSCs. MCL1 has been shown to localize in the mitochondrial matrix and contribute to mitochondrial respiration. Thus, we hypothesized that MCL1 contributes to enrichment of TNBC CSCs and chemotherapy resistance via mitochondrial regulation. Stable transfection and overexpression of MCL1 in MDA468 cells increased oxygen consumption ratio, mitochondrial membrane potential, and production of reactive oxygen species (ROS), all features of activated mtOXPHOS. Conversely, RNAi-mediated ablation of MCL1 in SUM159PT and MDA436 cells repressed these markers of activated mtOXPHOS. A mutant of MCL1 lacking its mitochondrial target sequences (MTS) was unable to localize in mitochondria and, when transfected into MDA468 cells, reduced the CD44high/CD24low fraction and mammosphere formation. We next tested VU0659158, a BH3 mimetic in development at Vanderbilt that disrupts MCL1 interactions with BH3 domain-containing proteins, such as BID, BIM, NOXA and PUMA. Treatment of SUM159PT cells with VU0659158 increased caspase activity but did not attenuate mammosphere formation. Analysis of mRNA expression in TCGA revealed that genes induced by mtOXPHOS involved in the hypoxia pathway are significantly up-regulated in MCL1 amplified breast cancers. Finally, pharmacological inhibition of HIF-1α, a key regulator of hypoxia, with digoxin decreased CSCs and attenuated tumor formation in vivo. These data suggest that 1) MCL1 confers resistance to chemotherapy by expanding CSCs via mtOXPHOS independent of its BH3 domain-mediated, anti-apoptotic function, and 2) targeting mitochondrial respiration and the hypoxia pathway may delay or reverse chemotherapy resistance in MCL1 amplified TNBC.
Citation Format: Kyung-min Lee, Jennifer Giltnane, Justin Balko, Luis Schwarz, Angel Guerrero, Katie Hutchinson, Mellissa Hicks, Violeta Sanchez, Melinda Sanders, Taekyu Lee, Edward Olejniczak, Stephen Fesik, Carlos Arteaga. Mitochondrial MCL1 maintains triple negative breast cancer stem cells and contributes to chemotherapy resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3890. doi:10.1158/1538-7445.AM2017-3890
Collapse
|
58
|
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] [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.
Collapse
|
59
|
Funk LM, Gunnar W, Dominitz JA, Eisenberg D, Frayne S, Maggard-Gibbons M, Kalarchian MA, Livingston E, Sanchez V, Smith BR, Weidenbacher H, Maciejewski ML. A Health Services Research Agenda for Bariatric Surgery Within the Veterans Health Administration. J Gen Intern Med 2017; 32:65-69. [PMID: 28271434 PMCID: PMC5359154 DOI: 10.1007/s11606-016-3951-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In 2016, the Veterans Health Administration (VHA) held a Weight Management State of the Art conference to identify evidence gaps and develop a research agenda for population-based weight management for veterans. Included were behavioral, pharmacologic, and bariatric surgery workgroups. This article summarizes the bariatric surgery workgroup (BSWG) findings and recommendations for future research. The BSWG agreed that there is evidence from randomized trials and large observational studies suggesting that bariatric surgery is superior to medical therapy for short- and intermediate-term remission of type 2 diabetes, long-term weight loss, and long-term survival. Priority evidence gaps include long-term comorbidity remission, mental health, substance abuse, and health care costs. Evidence of the role of endoscopic weight loss options is also lacking. The BSWG also noted the limited evidence regarding optimal timing for bariatric surgery referral, barriers to bariatric surgery itself, and management of high-risk bariatric surgery patients. Clinical trials of pre- and post-surgery interventions may help to optimize patient outcomes. A registry of overweight and obese veterans and a workforce assessment to determine the VHA's capacity to increase bariatric surgery access were recommended. These will help inform policy modifications and focus the research agenda to improve the ability of the VHA to deliver population-based weight management.
Collapse
|
60
|
Jovanović B, Mayer IA, Mayer EL, Abramson VG, Bardia A, Sanders ME, Kuba MG, Estrada MV, Beeler JS, Shaver TM, Johnson KC, Sanchez V, Rosenbluth JM, Dillon PM, Forero-Torres A, Chang JC, Meszoely IM, Grau AM, Lehmann BD, Shyr Y, Sheng Q, Chen SC, Arteaga CL, Pietenpol JA. A Randomized Phase II Neoadjuvant Study of Cisplatin, Paclitaxel With or Without Everolimus in Patients with Stage II/III Triple-Negative Breast Cancer (TNBC): Responses and Long-term Outcome Correlated with Increased Frequency of DNA Damage Response Gene Mutations, TNBC Subtype, AR Status, and Ki67. Clin Cancer Res 2017; 23:4035-4045. [PMID: 28270498 DOI: 10.1158/1078-0432.ccr-16-3055] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 01/17/2017] [Accepted: 03/02/2017] [Indexed: 12/31/2022]
Abstract
Purpose: Because of inherent disease heterogeneity, targeted therapies have eluded triple-negative breast cancer (TNBC), and biomarkers predictive of treatment response have not yet been identified. This study was designed to determine whether the mTOR inhibitor everolimus with cisplatin and paclitaxel would provide synergistic antitumor effects in TNBC.Methods: Patients with stage II/III TNBC were enrolled in a randomized phase II trial of preoperative weekly cisplatin, paclitaxel and daily everolimus or placebo for 12 weeks, until definitive surgery. Tumor specimens were obtained at baseline, cycle 1, and surgery. Primary endpoint was pathologic complete response (pCR); secondary endpoints included clinical responses, breast conservation rate, safety, and discovery of molecular features associated with outcome.Results: Between 2009 and 2013, 145 patients were accrued; 36% of patients in the everolimus arm and 49% of patients in the placebo arm achieved pCR; in each arm, 50% of patients achieved complete responses by imaging. Higher rates of neutropenia, mucositis, and transaminase elevation were seen with everolimus. Clinical response to therapy and long-term outcome correlated with increased frequency of DNA damage response (DDR) gene mutations, Basal-like1 and Mesenchymal TNBC-subtypes, AR-negative status, and high Ki67, but not with tumor-infiltrating lymphocytes.Conclusions: The paclitaxel/cisplatin combination was well tolerated and active, but addition of everolimus was associated with more adverse events without improvement in pCR or clinical response. However, discoveries made from correlative studies could lead to predictive TNBC biomarkers that may impact clinical decision-making and provide new avenues for mechanistic exploration that could lead to clinical utility. Clin Cancer Res; 23(15); 4035-45. ©2017 AACR.
Collapse
|
61
|
Balko JM, Loi S, Giltnane JM, Combs S, Estrada MV, Sanchez V, Rimm D, Sanders ME, Salgado R, Gomez H, Johnson DB. Abstract P6-10-02: MHC-II positive breast tumors are more immunogenic and may preferentially select for LAG-3-positive tumor immune infiltrates. Cancer Res 2017. [DOI: 10.1158/1538-7445.sabcs16-p6-10-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Lymphocyte-activation gene 3 (LAG-3) is a T-cell checkpoint regulator and a current target in immunotherapy trials. LAG-3's main ligand is MHC class II (MHC-II), to which it binds with higher affinity than CD4. Binding of LAG3 to MHC-II antigen-presenting cells negatively regulates cellular proliferation, activation, and homeostasis of T cells, similarly to CTLA-4 and PD-1, suggesting that antibodies targeting LAG-3 may demonstrate similar anti-tumor immune effects.
Hypothesis: We recently reported an association of MHC-II on tumor cells and its involvement in mediating sensitivity to PD-1/PD-L1 monoclonal antibodies. MHC-II demonstrates a strong bimodal expression pattern on tumor cells from a variety of tissues, including those of the breast. In breast cancer patients, tumor-specific MHC-II expression on TNBCs is correlated with a 'hot' immune environment. We hypothesized that 1) MHC-II expression may drive potent anti-tumor immune responses and 2) MHC-II-positive tumors that generate immunotolerance may develop a specific immune checkpoint dependency on LAG-3, since LAG-3 is the inhibitory receptor for MHC-II-mediated antigen presentation.
Methods: To determine the functionality of MHC-II in driving anti-tumor immune responses, we constitutively expressed the MHC-II master regulator CIITA in MMTV-neu mouse tumor cells and determined their ability to form tumors in immunocompetent syngeneic hosts. To evaluate the association of MHC-II+ tumors with LAG-3 expression, we evaluated LAG-3-positivity by immunohistochemistry (IHC) in lymphocytic infiltrates in a series of 111 post-NAC TNBC specimens from patients with residual disease remaining after presurgical chemotherapy. Tumor-infiltrating lymphocytes (TILs) were scored by H&E, PD-L1 and MHC-II (HLA-DR) were scored in the stroma and tumor compartments using automated quantitative immunofluorescence (AQUA).
Results: Enforced expression of MHC-II via constitutive expression of CIITA caused rejection in 60% of mice, while only 11% of mice rejected MMTV-neu tumors expressing the vector control (Fisher's exact p=0.04). All rejecting mice were immune to rechallenge with parental (non-CIITA-expressing) MMTV-neu cells, suggesting a memory effector response.
Clinically, 11/102 patients (10.8%) had LAG-3+ immune cells in their tumor. LAG-3+ tumors were strongly correlated with MHC-II positivity in tumor cells (p<0.0001). Presence of LAG-3+ cells also correlated strongly with overall TILs (p<0.0001), and PD-L1 expression on TILs (p<0.02). Since the likelihood of identifying LAG3+ lymphocytes is confounded by the inclusion of poorly-infiltrated tumors, we performed a subset analysis on only those tumors with substantial TILs (>20%). When this subset was analyzed, LAG-3 positivity retained its association with tumor MHC-II expression (p=0.0001), while the association of LAG-3 with stromal PD-L1 was reduced below the level of significance (p=0.052).
Conclusions: MHC-II expression causes increased immune activation in breast cancers, consistent with our previous findings. MHC-II positivity in breast tumors may identify a population with preferential dependence on the LAG-3 checkpoint, which may be important for future immunotherapy trials.
Citation Format: Balko JM, Loi S, Giltnane JM, Combs S, Estrada MV, Sanchez V, Rimm D, Sanders ME, Salgado R, Gomez H, Johnson DB. MHC-II positive breast tumors are more immunogenic and may preferentially select for LAG-3-positive tumor immune infiltrates [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-10-02.
Collapse
|
62
|
Williams MM, Lee L, Hicks DJ, Joly MM, Elion D, Rahman B, McKernan C, Sanchez V, Balko JM, Stricker T, Estrada MV, Cook RS. Key Survival Factor, Mcl-1, Correlates with Sensitivity to Combined Bcl-2/Bcl-xL Blockade. Mol Cancer Res 2016; 15:259-268. [PMID: 28039357 DOI: 10.1158/1541-7786.mcr-16-0280-t] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 11/16/2016] [Accepted: 12/12/2016] [Indexed: 12/15/2022]
Abstract
An estimated 40,000 deaths will be attributed to breast cancer in 2016, underscoring the need for improved therapies. Evading cell death is a major hallmark of cancer, driving tumor progression and therapeutic resistance. To evade apoptosis, cancers use antiapoptotic Bcl-2 proteins to bind to and neutralize apoptotic activators, such as Bim. Investigation of antiapoptotic Bcl-2 family members in clinical breast cancer datasets revealed greater expression and more frequent gene amplification of MCL1 as compared with BCL2 or BCL2L1 (Bcl-xL) across three major molecular breast cancer subtypes, Luminal (A and B), HER2-enriched, and Basal-like. While Mcl-1 protein expression was elevated in estrogen receptor α (ERα)-positive and ERα-negative tumors as compared with normal breast, Mcl-1 staining was higher in ERα+ tumors. Targeted Mcl-1 blockade using RNAi increased caspase-mediated cell death in ERα+ breast cancer cells, resulting in sustained growth inhibition. In contrast, combined blockade of Bcl-2 and Bcl-xL only transiently induced apoptosis, as cells rapidly acclimated through Mcl-1 upregulation and enhanced Mcl-1 activity, as measured in situ using Mcl-1/Bim proximity ligation assays. Importantly, MCL1 gene expression levels correlated inversely with sensitivity to pharmacologic Bcl-2/Bcl-xL inhibition in luminal breast cancer cells, whereas no relationship was seen between the gene expression of BCL2 or BCL2L1 and sensitivity to Bcl-2/Bcl-xL inhibition. These results demonstrate that breast cancers rapidly deploy Mcl-1 to promote cell survival, particularly when challenged with blockade of other Bcl-2 family members, warranting the continued development of Mcl-1-selective inhibitors for targeted tumor cell killing.Implications: Mcl-1 levels predict breast cancer response to inhibitors targeting other Bcl-2 family members, and demonstrate the key role played by Mcl-1 in resistance to this drug class. Mol Cancer Res; 15(3); 259-68. ©2016 AACR.
Collapse
|
63
|
Evangelista A, Rabasa JM, Mosquera VX, Barros A, Fernández-Tarrio R, Calvo-Iglesias F, Ferrera C, Rozado J, López-Ayerbe J, Garrote C, San román JA, Nistal F, Sanchez V, García Robles JA, Valera F, Ballester C, Gil-Albarova O, Domínguez F, Vivancos R, Mateo-Martinez A, Gallego P, González-Molina M, Fernández-Golfin C, Josa M, Hurlé A, Rodríguez-Sanchez I, Rodríguez-Palomares J. Diagnosis, management and mortality in acute aortic syndrome: results of the Spanish Registry of Acute Aortic Syndrome (RESA-II). EUROPEAN HEART JOURNAL-ACUTE CARDIOVASCULAR CARE 2016; 7:602-608. [DOI: 10.1177/2048872616682343] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Background: Recent advances in the diagnosis and treatment of acute aortic syndrome should improve the outcome of this disease. The Spanish Registry of Acute Aortic Syndrome aimed to assess current results in acute aortic syndrome management in a wide cohort of hospitals in the same geographical area. Methods: From January 2012 to January 2014, 26 tertiary hospitals included 629 consecutive patients with acute aortic syndrome: 73% men, mean age 64.7±14 years (range 22–92), 443 type A (70.4%) and 186 type B (29.6%). Results: Time elapsed between symptom onset and diagnosis was <12 hours in 70.7% of cases and <24 hours in 84.0% (median 5 hours; 25th–75th percentiles, 2.7–15.5 hours). Computed tomography was the first diagnostic technique in 78% of patients and transthoracic echocardiography in 15%. Surgical treatment was indicated in 78.3% of type A acute aortic syndrome. The interval between diagnosis and surgery was 4.8 hours (quartile 1–3, 2.5–11.4 hours). Among the patients with type B acute aortic syndrome, treatment was medical in 116 cases (62.4%), endovascular in 61 (32.8%) and surgical in nine (4.8%). Type A mortality during hospitalisation was 25.1% in patients treated surgically and 68% in those treated medically. Mortality in type B was 13.8% in those with medical treatment, 18.0% with endovascular therapy and 33.0% with surgical treatment. Conclusion: Improvements in the diagnosis and treatment of acute aortic syndrome have not resulted in a significant reduction in hospital mortality. The results of this study reflect more overall and less selected information on acute aortic syndrome management and the need for sustained advances in the therapeutic strategy of acute aortic syndrome.
Collapse
|
64
|
Desjarlais M, Dussault S, Sanchez V, Harel S, Hussain S, Rivard A. OXIDIZED LOW-DENSITY LIPOPROTEINS REDUCE MICRO-RNA 146B EXPRESSION AND LEAD TO ENDOTHELIAL DYSFUNCTION: ROLE OF TRAF6 SIGNALING PATHWAY. Can J Cardiol 2016. [DOI: 10.1016/j.cjca.2016.07.419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
65
|
Hutchinson KE, Johnson DB, Johnson AS, Sanchez V, Kuba M, Lu P, Chen X, Kelley MC, Wang Q, Zhao Z, Kris M, Berger MF, Sosman JA, Pao W. ERBB activation modulates sensitivity to MEK1/2 inhibition in a subset of driver-negative melanoma. Oncotarget 2016; 6:22348-60. [PMID: 26084293 PMCID: PMC4673168 DOI: 10.18632/oncotarget.4255] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Accepted: 06/01/2015] [Indexed: 12/22/2022] Open
Abstract
Melanomas are characterized by activating “driver” mutations in BRAF, NRAS, KIT, GNAQ, and GNA11. Resultant mitogen-activated protein kinase (MAPK) pathway signaling makes some melanomas susceptible to BRAF (BRAF V600 mutations), MEK1/2 (BRAF V600, L597, fusions; NRAS mutations), or other kinase inhibitors (KIT), respectively. Among driver-negative (“pan-negative”) patients, an unexplained heterogeneity of response to MEK1/2 inhibitors has been observed. Analysis of 16 pan-negative melanoma cell lines revealed that 8 (50%; termed Class I) are sensitive to the MEK1/2 inhibitor, trametinib, similar to BRAF V600E melanomas. A second set (termed Class II) display reduced trametinib sensitivity, paradoxical activation of MEK1/2 and basal activation of ERBBs 1, 2, and 3 (4 lines, 25%). In 3 of these lines, PI3K/AKT and MAPK pathway signaling is abrogated using the ERBB inhibitor, afatinib, and proliferation is even further reduced upon the addition of trametinib. A potential mechanism of ERBB activation in Class II melanomas is minimal expression of the ERK1/2 phosphatase, DUSP4, as ectopic restoration of DUSP4 attenuated ERBB signaling through potential modulation of the ERBB ligand, amphiregulin (AREG). Consistent with these data, immunohistochemical analysis of patient melanomas revealed a trend towards lower overall DUSP4 expression in pan-negative versus BRAF- and NRAS-mutant tumors. This study is the first to demonstrate that differential ERBB activity in pan-negative melanoma may modulate sensitivity to clinically-available MEK1/2 inhibitors and provides rationale for the use of ERBB inhibitors, potentially in combination with MEK1/2 inhibitors, in subsets of this disease.
Collapse
|
66
|
Hanker AB, Estrada MV, Zhao J, Cheng F, Moore PD, Tyson D, Sanchez V, Rexer BN, Sanders M, Zhao Z, Stricker TP, Arteaga CL. Abstract 302: ECM/Integrin signaling promotes resistance to the combination of HER2 and PI3K inhibitors in HER2+, PIK3CA-mutant breast cancer. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
HER2 amplification and activating mutations in PIK3CA, the gene encoding the p110α subunit of PI3K, often co-occur in breast cancer. We generated a transgenic mouse model of HER2-overexpressing (HER2+), PIK3CAH1047R-mutant breast cancer. In these mice, PIK3CAH1047R accelerates HER2-mediated tumor formation and promotes resistance to HER2 inhibitors (Hanker et al. PNAS 2013). HER2+/PIK3CA tumor growth was inhibited by treatment with the HER2 antibodies trastuzumab and pertuzumab in combination with the pan-PI3K inhibitor BKM120 (TPB). We sought to discover mechanisms of acquired resistance to the triple therapy by long-term treatment of established HER2+/PIK3CA tumors. Tumor transplants derived from a transgenic HER2+/PIK3CA tumor were initially growth inhibited by TPB. After several weeks, a subset of transplants (3/11) resumed growth in the presence of continuous TPB therapy. TPB-resistant tumors were cross-resistant to the combination of T + P + BYL719 (a p110α-specific inhibitor).
Whole exome sequencing did not identify acquired somatic alterations in TPB-resistant tumors, including in HER2. However, RNA-seq revealed significant transcriptional upregulation of extracellular matrix (ECM) genes and genes involved in cell adhesion, including collagens, tenascins, and thrombospondins. Likewise, trichrome staining revealed a significant increase in collagen fibers and IHC analysis confirmed increased Tenascin expression in the TPB-resistant tumor stroma. In addition, western blot analysis revealed increased expression of an activated form of integrin β1, a substrate for ECM ligands such as collagen, as well as P-SrcY416 (activated by integrins/focal adhesion). We also found that transcription of many of these genes is induced by short-term TPB treatment in human breast cancer cell lines by qRT-PCR.
Interestingly, primary tumor cells derived from TPB-resistant tumors no longer displayed resistance when grown in vitro. These cells regained TPB resistance when re-introduced into mice. Plating primary tumor cells on growth factor-reduced Matrigel or on Collagen I-coated plates restored resistance, suggesting that the ECM directly promotes TPB resistance. We are currently investigating whether inhibition of Integrin/Src signaling reverses TPB resistance. We are also exploring whether components of the ECM are altered in residual disease specimens from HER2+ breast cancer patients treated with neoadjuvant anti-HER2 therapies. Our data suggest that upregulation of ECM/integrin/Src signaling contributes to resistance to combinations of HER2 and PI3K inhibitors, and strongly support the growing body of literature indicating that components of the tumor microenvironment promote resistance to targeted therapies.
Citation Format: Ariella B. Hanker, Monica Valeria Estrada, Junfei Zhao, Feixiong Cheng, Preston D. Moore, Darren Tyson, Violeta Sanchez, Brent N. Rexer, Melinda Sanders, Zhongming Zhao, Thomas P. Stricker, Carlos L. Arteaga. ECM/Integrin signaling promotes resistance to the combination of HER2 and PI3K inhibitors in HER2+, PIK3CA-mutant breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 302.
Collapse
|
67
|
Sorace AG, Quarles CC, Sanchez V, Yankeelov TE. Abstract 4237: Decreased hypoxia in a HER2+ breast cancer model following trastuzumab therapy. Cancer Res 2016. [DOI: 10.1158/1538-7445.am2016-4237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Hypoxic tumors demonstrate treatment resistance with an increased risk of metastasis. Therefore, alleviating hypoxia has potential to improve efficiency of combination therapies. The primary goal of this study is to quantify alterations in hypoxia in response to trastuzumab in a murine model of HER2+ breast cancer through imaging and histology.
Experimental Design: Mice were implanted subcutaneously with BT474 breast cancer cells (107) and randomly assigned into treated (10 mg/kg trastuzumab) or control (saline) groups. After tumors reached ∼250 mm3, animals (n = 32) were utilized to identify longitudinal changes in functional vascular through an intravenous injection of Hoechst 33342 nuclear stain (immediately prior to sacrifice) and hypoxia through pimonidazole intravenous injection (one hour prior to sacrifice). Tumors were extracted for immunofluorescence between days 0 through 7. Tumor sections were flash frozen and stained with anti-pimonidazole and propidium iodide (nuclear counterstain). Additionally, a set of tumors (n = 36) were sacrificed for immunohistochemistry (days 0 through 7), formalin fixed and stained for CA-IX. All stained sections were scanned in high resolution (20×) and quantitatively analyzed with Leica SCN400 software. Another cohort of animals (n = 10) were imaged with 18F-FMISO (fluoromisonidazole) PET between days 0 through 7 and quantified via mean tracer concentration (%ID/g).
Results: Immunohistochemistry revealed significantly increased hypoxia in the control group compared to treated on days 3 (p = 0.03) and 7 (p = 0.002), as measured through CA-IX staining. Additionally, on day 4, functional vascular delivery was increased while hypoxia (pimonidazole) decreased in treated tumors compared to control. 18F-FMISO PET imaging corroborated histology findings with significantly decreased hypoxia in treated tumors compared to control tumors on day 7 (-47%; p<0.0001).
Conclusion: Trastuzumab has been shown to decrease hypoxia, as measured through gold-standard immunofluorescence. Additionally, this trastuzumab-induced improvement in tumor hypoxia can be measured via clinically relevant, noninvasive imaging (18F-FMISO PET). Temporarily improving the tumor's functional vasculature and decreasing hypoxia during trastuzumab treatment has potential to enhance the effectiveness of combination therapies. Identifying windows of improved vascular and cellular normalization with noninvasive medical imaging provide opportunity to decrease resistance to standard-of-care treatments and optimize therapeutic timing and regimens.
Citation Format: Anna G. Sorace, C. Chad Quarles, Violeta Sanchez, Thomas E. Yankeelov. Decreased hypoxia in a HER2+ breast cancer model following trastuzumab therapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4237.
Collapse
|
68
|
Sanchez V, Miassoedov A, Steinbrück M, Tromm W. KIT multi-physics tools for the analysis of design and beyond design basis accidents of light water reactors. KERNTECHNIK 2016. [DOI: 10.3139/124.110687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
This paper describes the KIT numerical simulation tools under extension and validation for the analysis of design and beyond design basis accidents (DBA) of Light Water Reactors (LWR). The description of the complex thermal hydraulic, neutron kinetics and chemo-physical phenomena going on during off-normal conditions requires the development of multi-physics and multi-scale simulations tools which are fostered by the rapid increase in computer power nowadays. The KIT numerical tools for DBA and beyond DBA are validated using experimental data of KIT or from abroad. The developments, extensions, coupling approaches and validation work performed at KIT are shortly outlined and discussed in this paper.
Collapse
|
69
|
Morrison Joly M, Hicks DJ, Jones B, Sanchez V, Estrada MV, Young C, Williams M, Rexer BN, Sarbassov DD, Muller WJ, Brantley-Sieders D, Cook RS. Rictor/mTORC2 Drives Progression and Therapeutic Resistance of HER2-Amplified Breast Cancers. Cancer Res 2016; 76:4752-64. [PMID: 27197158 DOI: 10.1158/0008-5472.can-15-3393] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/16/2016] [Indexed: 02/01/2023]
Abstract
HER2 overexpression drives Akt signaling and cell survival and HER2-enriched breast tumors have a poor outcome when Akt is upregulated. Akt is activated by phosphorylation at T308 via PI3K and S473 via mTORC2. The importance of PI3K-activated Akt signaling is well documented in HER2-amplified breast cancer models, but the significance of mTORC2-activated Akt signaling in this setting remains uncertain. We report here that the mTORC2 obligate cofactor Rictor is enriched in HER2-amplified samples, correlating with increased phosphorylation at S473 on Akt. In invasive breast cancer specimens, Rictor expression was upregulated significantly compared with nonmalignant tissues. In a HER2/Neu mouse model of breast cancer, genetic ablation of Rictor decreased cell survival and phosphorylation at S473 on Akt, delaying tumor latency, penetrance, and burden. In HER2-amplified cells, exposure to an mTORC1/2 dual kinase inhibitor decreased Akt-dependent cell survival, including in cells resistant to lapatinib, where cytotoxicity could be restored. We replicated these findings by silencing Rictor in breast cancer cell lines, but not silencing the mTORC1 cofactor Raptor (RPTOR). Taken together, our findings establish that Rictor/mTORC2 signaling drives Akt-dependent tumor progression in HER2-amplified breast cancers, rationalizing clinical investigation of dual mTORC1/2 kinase inhibitors and developing mTORC2-specific inhibitors for use in this setting. Cancer Res; 76(16); 4752-64. ©2016 AACR.
Collapse
|
70
|
Williams MM, Lee L, Morrison MM, McKernan C, Sanchez V, Hicks D, Stricker T, Cook RS. Abstract B07: Mcl-1-mediated resistance to ABT-263 is combated by mTOR inhibition in luminal breast cancers. Mol Cancer Res 2016. [DOI: 10.1158/1557-3125.advbc15-b07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
In the context of cancer, the intrinsic apoptotic pathway is exploited to favor tumor cell survival through overexpression of anti-apoptotic Bcl-2 family members (Bcl-A1, Bcl-2, Bcl-xL, Bcl-w and Mcl-1). We investigated targeting of anti-apoptotic Bcl-2 proteins in a panel of human luminal breast cancer cell lines. Use of ABT-263, the Bcl-2/Bcl-xL/Bcl-w inhibitor, induced transient tumor cell killing and decreased tumor cell growth in only 1 of 4 cell lines in three dimensional (3D) cultures. Mcl-1 expression and activity were rapidly upregulated upon ABT-263 treatment, highlighting the compensatory nature of Mcl-1. In luminal breast cancers, Mcl-1 was the most frequently amplified anti-apoptotic Bcl-2 family member according to The Cancer Genome Atlas, while nearly 80% of the luminal breast tumor epithelium was positive for Mcl-1 in a tissue microarray. Thus, we hypothesized that Mcl-1 may be a dominant tumor cell survival factor in luminal breast cancers.
Use of the mTOR inhibitor RAD001 (everolimus) to target Mcl-1 indirectly decreased tumor cell growth and increased tumor cell killing in 3 of 4 cell lines, as well as WAP-Myc luminal mammary tumors, demonstrating the effectiveness of Mcl-1 as a therapeutic target in breast cancers. While Mcl-1 inhibition alone did not affect growth of T47D cells, robust growth inhibition and tumor cell killing were seen in all cell lines upon inhibition of Mcl-1 using RAD001 or a EIF4 complex inhibitor (4E1RCat) in combination with ABT-263, suggesting that the induction of Mcl-1 upon ABT-263 treatment may be supported by increased cap-dependent translation. These results demonstrate that the sensitivity of luminal breast cancers to ABT-263 is enhanced by Mcl-1 inhibition, warranting further investigation into inhibition of anti-apoptotic Bcl-2 family proteins, in particular Mcl-1, as a clinical strategy to improve survival of patients with luminal breast cancers.
Citation Format: Michelle M. Williams, Linus Lee, Meghan M. Morrison, Courtney McKernan, Violeta Sanchez, Donna Hicks, Thomas Stricker, Rebecca S. Cook. Mcl-1-mediated resistance to ABT-263 is combated by mTOR inhibition in luminal breast cancers. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr B07.
Collapse
|
71
|
Johnson DB, Estrada MV, Salgado R, Sanchez V, Doxie DB, Opalenik SR, Vilgelm AE, Feld E, Johnson AS, Greenplate AR, Sanders ME, Lovly CM, Frederick DT, Kelley MC, Richmond A, Irish JM, Shyr Y, Sullivan RJ, Puzanov I, Sosman JA, Balko JM. Melanoma-specific MHC-II expression represents a tumour-autonomous phenotype and predicts response to anti-PD-1/PD-L1 therapy. Nat Commun 2016; 7:10582. [PMID: 26822383 PMCID: PMC4740184 DOI: 10.1038/ncomms10582] [Citation(s) in RCA: 386] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 12/31/2015] [Indexed: 12/18/2022] Open
Abstract
Anti-PD-1 therapy yields objective clinical responses in 30-40% of advanced melanoma patients. Since most patients do not respond, predictive biomarkers to guide treatment selection are needed. We hypothesize that MHC-I/II expression is required for tumour antigen presentation and may predict anti-PD-1 therapy response. In this study, across 60 melanoma cell lines, we find bimodal expression patterns of MHC-II, while MHC-I expression was ubiquitous. A unique subset of melanomas are capable of expressing MHC-II under basal or IFNγ-stimulated conditions. Using pathway analysis, we show that MHC-II(+) cell lines demonstrate signatures of 'PD-1 signalling', 'allograft rejection' and 'T-cell receptor signalling', among others. In two independent cohorts of anti-PD-1-treated melanoma patients, MHC-II positivity on tumour cells is associated with therapeutic response, progression-free and overall survival, as well as CD4(+) and CD8(+) tumour infiltrate. MHC-II(+) tumours can be identified by melanoma-specific immunohistochemistry using commercially available antibodies for HLA-DR to improve anti-PD-1 patient selection.
Collapse
|
72
|
Ivanov A, Sanchez V, Stieglitz R, Ivanov K. Large-scale Monte Carlo neutron transport calculations with thermal hydraulic feedback. ANN NUCL ENERGY 2015. [DOI: 10.1016/j.anucene.2014.12.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
73
|
Morrison MM, Jones B, Sanchez V, Estrada MV, Hicks D, Williams M, Brantley-Sieders D, Cook R. Abstract 511: Rictor/mTORC2 drives formation, progression and therapeutic resistance of HER2-amplified breast cancers. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The phosphatidyl inositol-3-kinase (PI3K)/Akt signaling pathway is aberrantly activated in nearly 60% of breast cancers, through HER2 amplification, PIK3CA mutation, PTEN inactivation, and other alterations. The mTOR complexes mTORC1 and mTORC2 operate as activators (mTORC2) or effectors (mTORC1) of Akt. We found that mRNA upregulation in the mTORC2 cofactors RICTOR and MAPKAP1 correlated with poor survival in breast cancer patients, while upregulation in the mTORC1 cofactor RPTOR did not. Genomic gains of RICTOR and MAPKAP1 occurred more frequently in breast cancers with PI3K pathway alterations than genomic RPTOR gains. Importantly, Rictor protein levels were increased in invasive over non-invasive breast tumors, while Raptor levels were not. RICTOR gene ablation in a transgenic mouse model of HER2-amplified breast cancer delayed tumorigenesis and decreased lung metastasis, Akt-S473 phosphorylation, cell growth and survival. In human HER2-amplified breast cancer cells, Rictor loss, but not Raptor loss, decreased Akt-S473 phosphorylation, reducing cell survival and motility/invasion. Interestingly, Rictor/mTORC2 loss or treatment with a dual mTORC1/2 inhibitor improved lapatinib-induced cell killing in parental and lapatinib-resistant tumor cells to a greater extent than mTORC1 inhibition. Akt re-activation rescued cell survival, but not motility/invasion, in Rictor-depleted cells. However, Rictor loss caused accumulation of the Rac inhibitor RhoGDI2, thus impairing Rac1-dependent invasion. We conclude that HER2-amplified breast cancers use Rictor/mTORC2 to drive Akt-mediated cell survival and Rac1-mediated cellular invasion. These studies support additional studies into mTORC2-specific inhibitors.
Citation Format: Meghan M. Morrison, Bayley Jones, Violeta Sanchez, Monica V. Estrada, Donna Hicks, Michelle Williams, Dana Brantley-Sieders, Rebecca Cook. Rictor/mTORC2 drives formation, progression and therapeutic resistance of HER2-amplified breast cancers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 511. doi:10.1158/1538-7445.AM2015-511
Collapse
|
74
|
Weis JA, Flint KM, Sanchez V, Yankeelov TE, Miga MI. Assessing the accuracy and reproducibility of modality independent elastography in a murine model of breast cancer. J Med Imaging (Bellingham) 2015; 2:036001. [PMID: 26158120 DOI: 10.1117/1.jmi.2.3.036001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 06/02/2015] [Indexed: 01/21/2023] Open
Abstract
Cancer progression has been linked to mechanics. Therefore, there has been recent interest in developing noninvasive imaging tools for cancer assessment that are sensitive to changes in tissue mechanical properties. We have developed one such method, modality independent elastography (MIE), that estimates the relative elastic properties of tissue by fitting anatomical image volumes acquired before and after the application of compression to biomechanical models. The aim of this study was to assess the accuracy and reproducibility of the method using phantoms and a murine breast cancer model. Magnetic resonance imaging data were acquired, and the MIE method was used to estimate relative volumetric stiffness. Accuracy was assessed using phantom data by comparing to gold-standard mechanical testing of elasticity ratios. Validation error was [Formula: see text]. Reproducibility analysis was performed on animal data, and within-subject coefficients of variation ranged from 2 to 13% at the bulk level and 32% at the voxel level. To our knowledge, this is the first study to assess the reproducibility of an elasticity imaging metric in a preclinical cancer model. Our results suggest that the MIE method can reproducibly generate accurate estimates of the relative mechanical stiffness and provide guidance on the degree of change needed in order to declare biological changes rather than experimental error in future therapeutic studies.
Collapse
|
75
|
Williams MM, Lee L, Morrison MM, Williams AJ, Sanchez V, Hicks D, Cook R. Abstract B09: Targeting the anti-apoptotic protein Mcl-1 with the mTOR inhibitor RAD001 sensitizes luminal breast cancers to the Bcl-2/Bcl-xL inhibitor ABT-263. Mol Cancer Ther 2015. [DOI: 10.1158/1538-8514.pi3k14-b09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
In an effort to enhance therapeutic tumor cell killing in luminal breast cancers, we investigated the inhibition of the anti-apoptotic Bcl-2 family proteins Bcl-2, Bcl-xL and Mcl-1. Anti-apoptotic Bcl-2 proteins are inhibitors of the intrinsic apoptotic pathway that sequester and inhibit pro-apoptotic Bcl-2 family members. Sustained overexpression of anti-apoptotic Bcl-2 family members frequently occurs in cancers and supports tumor initiation, tumor progression, therapeutic resistance and poor patient survival. While only 2/324 and 1/324 luminal breast cancers curated by The Cancer Genome Atlas (TCGA) had gene amplification of BCL2 and BCL2L1 (encoding Bcl-xL) respectively, 21/324 (<8%) displayed MCL1 amplification. Wap-Myc transgenic mouse mammary tumors, which are highly enriched for the luminal A transcription signature, displayed profoundly increased Mcl-1 levels as compared to normal mammary tissue, suggesting a role for Mcl-1 in luminal breast cancer biology. Using a panel of four MCL1-amplified breast cancer cell lines, we found that two were marginally sensitive to treatment with ABT-263, a BH3-mimetic that targets Bcl-2 and Bcl-xL. Conversely, ectopic overexpression of Mcl-1 decreased sensitivity to ABT-263. ABT-263 induced minimal cell killing in MCF7 xenografts and had no effect on tumor growth. Similarly, ABT-263 did not affect tumor growth in luminal-like Wap-Myc mouse mammary tumors. Thus, luminal breast cancer cells expressing increased Mcl-1 are poorly responsive to Bcl-2/Bcl-xL inhibition.
Upregulation of Mcl-1 expression and activity, an established ABT-263-resistance mechanism in leukemias and lymphomas, was observed in MCL1-amplified luminal breast cancer cell lines treated with ABT-263 in culture and in vivo. ABT-263 also increased the anti-apoptotic activity of Mcl-1 towards the pro-apoptotic Bcl-2 family member BIM, suggesting that Mcl-1 upregulation compensates for inhibition of Bcl-2 and Bcl-xL by ABT-263. There are currently no Mcl-1 specific inhibitors. However, Mcl-1 undergoes cap-dependent translation, and thus inhibition of cap-dependent translation has been proposed as a method to inhibit the protein expression of Mcl-1. Importantly, the mTOR pathway is required for efficient cap-dependent translation in many cancer cells. We found that the rapalogue RAD001/everolimus, an mTOR inhibitor, decreased Mcl-1 protein levels in MCL1-amplified luminal breast cancer cell lines. Furthermore, RAD001 blocked Mcl-1 protein upregulation in response to ABT-263, producing increased cell killing and decreased cell growth in all MCL1-amplified luminal breast cancer cell lines. Treatment of luminal Wap-Myc mammary tumors with RAD001 decreased tumor volume by 40%, while treatment with ABT-263 had no effect on tumor volume. These data suggest that Mcl-1 targeting may be superior to Bcl-2/Bcl-xL targeting in luminal breast cancers, particularly in luminal breast cancers with MCL1-amplification. Furthermore, we have identified the mTOR pathway as a potential therapeutic target for blocking Mcl-1 expression in luminal breast cancers.
Citation Format: Michelle M. Williams, Linus Lee, Meghan M. Morrison, Andrew J. Williams, Violeta Sanchez, Donna Hicks, Rebecca Cook. Targeting the anti-apoptotic protein Mcl-1 with the mTOR inhibitor RAD001 sensitizes luminal breast cancers to the Bcl-2/Bcl-xL inhibitor ABT-263. [abstract]. In: Proceedings of the AACR Special Conference: Targeting the PI3K-mTOR Network in Cancer; Sep 14-17, 2014; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(7 Suppl):Abstract nr B09.
Collapse
|