Synthetic lethality-based strategy has been developed to identify therapeutic targets in cancer harboring tumor suppressor gene mutations, as exemplified by the effectiveness of PARP inhibitors in BRCA1/2-mutated tumors. However, many synthetic lethal interactors are less reliable due to the fact that such genes usually do not perform fundamental or indispensable functions in the cell. Here we developed an approach to identify the “essential lethality” arose from these mutated/deleted essential genes, which are largely tolerated in cancer cells due to genetic redundancy. We uncovered the cohesion subunit SA1 as a putative synthetic-essential target in cancers carrying inactivating mutations of its paralog, SA2. In SA2-deficient Ewing sarcoma and bladder cancer, further depletion of SA1 profoundly and specifically suppressed cancer cell proliferation, survival and tumorigenic potential. Mechanistically, inhibition of SA1 in the SA2-mutated cells led to premature chromatid separation, dramatic extension of mitotic duration, and consequently lethal failure of cell division. More importantly, depletion of SA1 rendered those SA2-mutated cells more susceptible to DNA damage, especially double-strand breaks (DSBs), due to reduced functionality of DNA repair. Furthermore, inhibition of SA1 sensitized the SA2-deficient cancer cells to PARP inhibitors in vitro and in vivo, providing a potential therapeutic strategy for patients with SA2-deficient tumors.
Yunhua Liu, Hanchen Xu, Kevin Van der Jeught, Yujing Li, Sheng Liu, Lu Zhang, Yuanzhang Fang, Xinna Zhang, Milan Rodovich, Bryan P. Schneider, Xiaoming He, Cheng Huang, Chi Zhang, Jun Wan, Guang Ji, Xiongbin Lu
BACKGROUND. Monogenic Interferon (IFN)-mediated autoinflammatory diseases present in infancy with systemic inflammation, an IFN-response-gene-signature (IRS), inflammatory organ damage and high mortality. We used the janus kinase (JAK) inhibitor baricitinib with IFN-blocking activity in vitro, to ameliorate disease. METHODS. Between October 2011 and February 2017, 10 patients with CANDLE (chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperatures), 4 with SAVI (Stimulator of IFN genes (STING)-associated vasculopathy with onset in infancy), and 4 patients with other interferonopathies were enrolled in an Expanded Access Program. Patients underwent dose-escalation, benefit was assessed by reductions in daily disease symptoms and corticosteroid requirement. Quality-of-life, organ inflammation, changes in IFN-induced biomarkers, and safety were longitudinally assessed. RESULTS. 18 patients were treated for a mean duration of 3.0 years (1.5–4.9 years). The median daily symptom score decreased from 1.3 (IQR 0.93–1.78) to 0.25 (IQR 0.1-0.63) (P < 0.0001). In 14 patients receiving steroids at baseline, daily prednisone doses decreased from 0.44 mg/kg/day (IQR 0.31–1.09) to 0.11 mg/kg/day (IQR 0.02–0.24) (P < 0.01); 5 of 10 CANDLE patients achieved lasting clinical remission. Quality of life, height and bone mineral density Z-scores significantly improved, and IFN biomarkers decreased. Three patients discontinued, two with genetically undefined conditions due to lack of efficacy, and one CANDLE patient due to BK viremia and azotemia. The most common adverse events were upper respiratory infections, gastroenteritis, BK viruria and viremia. CONCLUSION. On baricitinib treatment, clinical manifestations, inflammatory and IFN biomarkers improved in patients with the monogenic interferonopathies, CANDLE, SAVI and 2 other interferonopathies. Monitoring safety and efficacy is important in benefit-risk assessment. TRIAL REGISTRATION. ClinicalTrials.gov NCT01724580 and NCT02974595. FUNDING. NIH, NIAID, NIAMS, NIDDK, NHLBI, NINDS, and the Clinical Center. Baricitinib was provided by Eli Lilly. Eli Lilly is the sponsor of the compassionate use program.
Gina A. Montealegre Sanchez, Adam Reinhardt, Suzanne Ramsey, Helmut Wittkowski, Philip J. Hashkes, Yackov Berkun, Susanne Schalm, Sara Murias, Jason A. Dare, Diane Brown, Deborah L. Stone, Ling Gao, Thomas Klausmeier, Dirk Foell, Adriana A. de Jesus, Dawn C. Chapelle, Hanna Kim, Samantha Dill, Robert Colbert, Laura Failla, Bahar Kost, Michelle O'Brien, James C. Reynolds, Les R. Folio, Katherine R. Calvo, Scott M. Paul, Nargues Weir, Alessandra Brofferio, Ariane Soldatos, Angélique Biancotto, Edward W. Cowen, John G. Digiovanna, Massimo Gadina, Andrew J. Lipton, Colleen Hadigan, Steven M. Holland, Joseph Fontana, Ahmad S. Alawad, Rebecca J. Brown, Kristina I. Rother, Theo Heller, Kristina M. Brooks, Parag Kumar, Stephen R. Brooks, Meryl Waldman, Harsharan K. Singh, Volker Nickeleit, Maria Silk, Apurva Prakash, Jonathan M. Janes, Seza Ozen, Paul G. Wakim, Paul A. Brogan, William L. Macias, Raphaela Goldbach-Mansky
Although aberrant Epidermal Growth Factor Receptor (EGFR) signaling is widespread in cancer, EGFR inhibition is effective only in a subset of NSCLC (non-small cell lung cancer) with EGFR activating mutations. A majority of NSCLCs express EGFR wild type (EGFRwt) and do not respond to EGFR inhibition. Tumor necrosis factor (TNF) is a major mediator of inflammation-induced cancer. We find that a rapid increase in TNF level is a universal adaptive response to EGFR inhibition in NSCLC regardless of EGFR status. EGFR signaling actively suppresses TNF mRNA levels by inducing expression of miR-21 resulting in decreased TNF mRNA stability. Conversely, EGFR inhibition results in loss of miR-21 and increased TNF mRNA stability. In addition, TNF-induced NF-kB activation leads to increased TNF transcription in a feedforward loop. Inhibition of TNF signaling renders EGFRwt expressing NSCLC cell lines and an EGFRwt Patient-Derived Xenograft (PDX) model highly sensitive to EGFR inhibition. In EGFR mutant oncogene-addicted cells, blocking TNF enhances the effectiveness of EGFR inhibition. EGFR plus TNF inhibition is also effective in NSCLC with acquired resistance to EGFR inhibition. We suggest concomitant EGFR and TNF inhibition as a new treatment approach that could be beneficial for a majority of lung cancer patients.
Ke Gong, Gao Guo, David E. Gerber, Boning Gao, Michael Peyton, Chun Huang, John D. Minna, Kimmo J. Hatanpaa, Kemp Kernstine, Ling Cai, Yang Xie, Hong Zhu, Farjana Fattah, Shanrong Zhang, Masaya Takahashi, Bipasha Mukherjee, Sandeep Burma, Jonathan Dowell, Kathryn Dao, Vassiliki A. Papadimitrakopoulou, Victor Olivas, Trever G. Bivona, Dawen Zhao, Amyn A. Habib
Thiazolidinediones (TZDs) are PPARγ agonists with potent insulin-sensitizing effects. However, their use has been curtailed by significant adverse effects on weight, bone, heart, and hemodynamic balance. TZDs induce the deacetylation of PPARγ on K268 and K293 to cause the browning of white adipocytes. Here we showed that targeted PPARγ mutations resulting in constitutive deacetylation (K268R/K293R, 2KR) increased energy expenditure, and protected from visceral adiposity and diet-induced obesity by augmenting brown remodeling of white adipose tissues. Strikingly, when 2KR mice were treated with rosiglitazone, they maintained the insulin-sensitizing, glucose-lowering response to TZDs, while displaying little, if any, adverse effects on fat deposition, bone density, fluid retention, and cardiac hypertrophy. Thus, deacetylation appears to fulfill the goal of dissociating the metabolic benefits of PPARγ activation from its adverse effects. Strategies to leverage PPARγ deacetylation may lead to the design of safer, more effective agonists of this nuclear receptor in the treatment of metabolic diseases.
Michael J. Kraakman, Qiongming Liu, Jorge Postigo-Fernandez, Ruiping Ji, Ning Kon, Delfina Larrea, Maria Namwanje, Lihong Fan, Michelle Chan, Estela Area-Gomez, Wenxian Fu, Remi J. Creusot, Li Qiang
BACKGROUND. Poly(ADP-ribose) polymerase (PARP) inhibitors are effective in a broad population of ovarian cancer patients, however resistance caused by low enzyme expression of the drug target, poly(ADP-ribose) polymerase 1 (PARP-1), remains to be clinically evaluated in this context. We hypothesize that PARP-1 expression is variable in ovarian cancer and can be quantified in primary and metastatic disease using a novel positron emitting tomography (PET) imaging agent. METHODS. We used a translational approach to describe the significance of PET imaging of PARP-1 in ovarian cancer. First, we produced PARP1 KO ovarian cancer cell lines using CRISPR/Cas9 gene editing to test loss of PARP-1 as a resistance mechanism to all clinically used PARP inhibitors. Next, we performed pre-clinical microPET imaging studies using ovarian cancer patient derived xenografts in mouse models. Finally, in a phase 1 PET imaging clinical trial we explored PET imaging as a regional marker of PARP-1 expression in primary and metastatic disease through correlative tissue histology. RESULTS. We found deletion of PARP1 causes resistance to all PARP inhibitors in vitro and microPET imaging provides proof of concept as an approach to quantify PARP-1 in vivo. Clinically, we observed a spectrum of standard uptake values (SUVs) for PARP-1 in tumors ranging from 2-12. In addition, we found a positive correlation between PET SUVs and fluorescent immunohistochemistry for PARP-1 (r2: 0.60). CONCLUSIONS. This work confirms the translational potential of a PARP-1 PET imaging agent and supports future clinical trials to test PARP-1 expression as a method to stratify patients for PARP inhibitor therapy. Clinicaltrials.gov: NCT02637934.
Mehran Makvandi, Austin Pantel, Lauren Schwartz, Erin Schubert, Kuiying Xu, Chia-Ju Hsieh, Catherine Hou, Hyoung Kim, Chi-Chang Weng, Harrison Winters, Robert Doot, Michael D. Farwell, Daniel A. Pryma, Roger A. Greenberg, David A. Mankoff, Fiona Simpkins, Robert H. Mach, Lilie L. Lin
A key predictor for the success of gene-modified T cell therapies for cancer is the persistence of transferred cells in the patient. The propensity of less differentiated memory T cells to expand and survive efficiently has therefore made them attractive candidates for clinical application. We hypothesized that re-directing T cells to specialized niches in the bone marrow (BM) that support memory differentiation would confer increased therapeutic efficacy. We show that overexpression of chemokine receptor CXCR4 in CD8+ T cells (TCXCR4) enhanced their migration towards vascular-associated CXCL12+ cells in the BM and increased their local engraftment. Increased access of TCXCR4 to the BM microenvironment induced IL-15-dependent homeostatic expansion and promoted the differentiation of memory precursor-like cells with low expression of programmed death-1, resistance to apoptosis and a heightened capacity to generate poly-functional cytokine-producing effector cells. Following transfer to lymphoma-bearing mice, TCXCR4 showed a greater capacity for effector expansion and better tumor protection, the latter being independent of changes in trafficking to the tumor bed or local out-competition of regulatory T cells. Thus, re-directed homing of T cells to the BM confers increased memory differentiation and anti-tumor immunity, suggesting an innovative solution to increase the persistence and functions of therapeutic T cells.
Anjum B. Khan, Ben Carpenter, Pedro Santos e Sousa, Constandina Pospori, Reema Khorshed, James Griffin, Pedro Veliça, Mathias Zech, Sara Ghorashian, Calum Forrest, Sharyn Thomas, Sara Gonzalez Anton, Maryam Ahmadi, Angelika Holler, Barry Flutter, Zaida Ramirez-Ortiz, Terry K. Means, Clare L. Bennett, Hans Stauss, Emma Morris, Cristina Lo Celso, Ronjon Chakraverty
The unfolded protein response (UPR) is a cellular homeostatic mechanism that is activated in many human cancers and plays pivotal roles in tumor progression and therapy resistance. However, the molecular mechanisms for UPR activation and regulation in cancer cells remain elusive. Here, we show that oncogenic MYC regulates the inositol-requiring enzyme 1 (IRE1)/X-box binding protein 1 (XBP1) branch of the UPR in breast cancer via multiple mechanisms. We found that MYC directly controls IRE1 transcription by binding to its promoter and enhancer. Furthermore, MYC forms a transcriptional complex with XBP1, a target of IRE1, and enhances its transcriptional activity. Importantly, we demonstrate that XBP1 is a synthetic lethal partner of MYC. Silencing of XBP1 selectively blocked the growth of MYC-hyperactivated cells. Pharmacological inhibition of IRE1 RNase activity with small molecule inhibitor 8866 selectively restrained the MYC-overexpressing tumor growth in vivo in a cohort of preclinical patient-derived xenograft models and genetically engineered mouse models. Strikingly, 8866 substantially enhanced the efficacy of docetaxel chemotherapy, resulting in rapid regression of MYC-overexpressing tumors. Collectively, these data establish the synthetic lethal interaction of the IRE1/XBP1 pathway with MYC hyperactivation and provide a potential therapy for MYC-driven human breast cancers.
Na Zhao, Jin Cao, Longyong Xu, Qianzi Tang, Lacey E. Dobrolecki, Xiangdong Lv, Manisha Talukdar, Yang Lu, Xiaoran Wang, Dorothy Z. Hu, Qing Shi, Yu Xiang, Yunfei Wang, Xia Liu, Wen Bu, Yi Jiang, Mingzhou Li, Yingyun Gong, Zheng Sun, Haoqiang Ying, Bo Yuan, Xia Lin, Xin-Hua Feng, Sean M. Hartig, Feng Li, Haifa Shen, Yiwen Chen, Leng Han, Qingping Zeng, John B. Patterson, Benny Abraham Kaipparettu, Nagireddy Putluri, Frank Sicheri, Jeffrey M. Rosen, Michael T. Lewis, Xi Chen
BACKGROUND. Sporadic vascular malformations (VMs) are complex congenital anomalies of blood vessels that lead to stroke, life-threatening bleeds, disfigurement, overgrowth, and/or pain. Therapeutic options are severely limited and multi-disciplinary management remains challenging, particularly for high-flow arteriovenous malformations (AVM). METHODS. To investigate the pathogenesis of sporadic intracranial and extracranial VMs in 160 children in which known genetic causes had been excluded, we sequenced DNA from affected tissue and optimised analysis for detection of low mutant allele frequency. RESULTS. We discovered multiple mosaic activating variants in four genes of the RAS-MAPK pathway, KRAS, NRAS, BRAF, and MAP2K1, a pathway commonly activated in cancer and responsible for the germ-line RAS-opathies. These variants were more frequent in high-flow than low-flow VMs. In vitro characterisation and two transgenic zebrafish AVM models which recapitulated the human phenotype validated the pathogenesis of the mutant alleles. Importantly, treatment of AVM-BRAF mutant zebrafish with the BRAF inihibitor, Vemurafinib, restored blood flow in AVM. CONCLUSIONS. Our findings uncover a major cause of sporadic vascular malformations of different clinical types, and thereby offer the potential of personalised medical treatment by repurposing existing licensed cancer therapies. FUNDING. This work was funded or supported by grants from AVM Butterfly Charity, the Wellcome Trust (UK), the Medical Research Council (UK), the UK National Institute for Health Research, L’Oreal-Melanoma Research Alliance, the European Research Council, and the National Human Genome Research (US).
Lara Al-Olabi, Satyamaanasa Polubothu, Katherine Dowsett, Katrina A. Andrews, Paulina Stadnik, Agnel P. Joseph, Rachel Knox, Alan Pittman, Graeme Clark, William Baird, Neil Bulstrode, Mary Glover, Kristiana Gordon, Darren Hargrave, Susan M. Huson, Thomas S. Jacques, Gregory James, Hannah Kondolf, Loshan Kangesu, Kim M. Keppler-Noreuil, Amjad Khan, Marjorie J. Lindhurst, Mark Lipson, Sahar Mansour, Justine O'Hara, Caroline Mahon, Anda Mosica, Celia Moss, Aditi Murthy, Juling Ong, Victoria E. Parker, Jean-Baptiste Rivière, Julie C. Sapp, Neil J. Sebire, Rahul Shah, Branavan Sivakumar, Anna Thomas, Alex Virasami, Regula Waelchli, Zhiqiang Zeng, Leslie G. Biesecker, Alex Barnacle, Maya Topf, Robert K. Semple, E. Elizabeth Patton, Veronica A. Kinsler
Myc activation is a primary oncogenic event in many human cancers; however, these transcription factors are difficult to inhibit pharmacologically, suggesting that Myc-dependent downstream effectors may be more tractable therapeutic targets. Here we show that Myc overexpression induces endoplasmic reticulum (ER) stress and engages the IRE1α-XBP1 pathway through multiple molecular mechanisms in a variety of c-Myc- and N-Myc-dependent cancers. In particular, Myc-overexpressing cells require IRE1α-XBP1 signaling for sustained growth and survival in vitro and in vivo, dependent on elevated stearoyl-CoA-desaturase 1 (SCD1) activity. Pharmacological and genetic XBP1 inhibition induces Myc-dependent apoptosis, which is alleviated by exogenous unsaturated fatty acids. Of note, SCD1 inhibition phenocopies IRE1α RNase activity suppression in vivo. Furthermore, IRE1α inhibition enhances the cytotoxic effects of standard chemotherapy drugs used to treat c-Myc-overexpressing Burkitt’s lymphoma, suggesting that inhibiting the IRE1α-XBP1 pathway is a useful general strategy for treatment of Myc-driven cancers.
Hong Xie, Chih-Hang Anthony Tang, Jun H. Song, Anthony Mancuso, Juan R. Del Valle, Jin Cao, Yan Xiang, Chi V. Dang, Roy Lan, Danielle J. Sanchez, Brian Keith, Chih-Chi Andrew Hu, M. Celeste Simon
Aberrant activation of MAPK signaling leads to activation of oncogenic transcriptomes. How MAPK signaling is coupled with transcriptional response in cancer is not fully understood. In gastrointestinal stromal tumor and melanoma, both with oncogenic MAPK activation, we find that ETV1 and other Pea3-ETS transcription factors are critical nuclear effectors of MAPK signaling that are regulated through protein stability. Expression of stabilized Pea3-ETS factors can partially rescue the MAPK transcriptome and cell viability after MAPK inhibition. To identify players involved in this process, we performed a pooled genome-wide RNAi screen using a novel fluorescence-based ETV1 protein stability sensor, and identified COP1, DET1, DDB1, UBE3C, PSMD4, and COP9 signalosome members. COP1 and DET1 loss led to decoupling between MAPK signaling and downstream transcriptional response, where MAPK inhibition failed to destabilize Pea3 factors and fully inhibit the MAPK transcriptome, thus resulting in decreased sensitivity to MAPK pathway inhibitors. We identified multiple COP1 and DET1 mutations in human tumors that were defective in degradation of Pea3-ETS factors. Two melanoma patients had de novo DET1 mutations arising after vemurafenib treatment. These observations indicate that MAPK signaling-dependent regulation of Pea3-ETS protein stability is a key signaling node in oncogenesis and therapeutic resistance to MAPK pathway inhibition.
Yuanyuan Xie, Zhen Cao, Elissa W.P. Wong, Youxin Guan, Wenfu Ma, Jenny Q. Zhang, Edward G. Walczak, Devan Murphy, Leili Ran, Inna Sirota, Shangqian Wang, Shipra Shukla, Dong Gao, Simon R.V. Knott, Kenneth Chang, Justin Leu, John Wongvipat, Cristina R. Antonescu, Gregory Hannon, Ping Chi, Yu Chen
No posts were found with this tag.