Increased rates of locoregional recurrence are observed in patients with basal-like breast cancer (BC) despite the use of radiation therapy (RT); therefore, approaches that result in radiosensitization of basal-like BC are critically needed. Using patients’ tumor gene expression data from 4 independent data sets, we correlated gene expression with recurrence to find genes significantly correlated with early recurrence after RT. The highest-ranked gene, TTK, was most highly expressed in basal-like BC across multiple data sets. Inhibition of TTK by both genetic and pharmacologic methods enhanced radiosensitivity in multiple basal-like cell lines. Radiosensitivity was mediated, at least in part, through persistent DNA damage after treatment with TTK inhibition and RT. Inhibition of TTK impaired homologous recombination (HR) and repair efficiency, but not nonhomologous end-joining, and decreased the formation of Rad51 foci. Reintroduction of wild-type TTK rescued both radioresistance and HR repair efficiency after TTK knockdown, however, reintroduction of kinase-dead TTK did not. In vivo, TTK inhibition combined with RT led to a significant decrease in tumor growth in both heterotopic and orthotopic, including patient-derived xenograft, BC models. These data support the rationale for clinical development of TTK inhibition as a radiosensitizing strategy for patients with basal-like BC, and efforts toward this end are currently underway.
Benjamin C. Chandler, Leah Moubadder, Cassandra L. Ritter, Meilan Liu, Meleah Cameron, Kari Wilder-Romans, Amanda Zhang, Andrea M. Pesch, Anna R. Michmerhuizen, Nicole Hirsh, Marlie Androsiglio, Tanner Ward, Eric Olsen, Yashar S. Niknafs, Sofia Merajver, Dafydd G. Thomas, Powel H. Brown, Theodore S. Lawrence, Shyam Nyati, Lori J. Pierce, Arul Chinnaiyan, Corey Speers
Antigen receptor–dependent (AgR-dependent) stimulation of the NF-κB transcription factor in lymphocytes is a required event during adaptive immune response, but dysregulated activation of this signaling pathway can lead to lymphoma. AgR stimulation promotes assembly of the CARMA1-BCL10-MALT1 complex, wherein MALT1 acts as (a) a scaffold to recruit components of the canonical NF-κB machinery, and (b) a protease to cleave and inactivate specific substrates, including negative regulators of NF-κB. In multiple lymphoma subtypes, malignant B cells hijack AgR signaling pathways to promote their own growth and survival, and inhibiting MALT1 reduces the viability and growth of these tumors. As such, MALT1 has emerged as a potential pharmaceutical target. Here, we identified G protein–coupled receptor kinase 2 (GRK2) as a new MALT1-interacting protein. We demonstrated that GRK2 binds the death domain of MALT1 and inhibits MALT1 scaffolding and proteolytic activities. We found that lower GRK2 levels in activated B cell–type diffuse large B cell lymphoma (ABC-DLBCL) are associated with reduced survival, and that GRK2 knockdown enhances ABC-DLBCL tumor growth in vitro and in vivo. Together, our findings suggest that GRK2 can function as a tumor suppressor by inhibiting MALT1 and provide a roadmap for developing new strategies to inhibit MALT1-dependent lymphomagenesis.
Jing Cheng, Linda R. Klei, Nathaniel E. Hubel, Ming Zhang, Rebekka Schairer, Lisa M. Maurer, Hanna B. Klei, Heejae Kang, Vincent J. Concel, Phillip C. Delekta, Eric V. Dang, Michelle A. Mintz, Mathijs Baens, Jason G. Cyster, Narayanan Parameswaran, Margot Thome, Peter C. Lucas, Linda M. McAllister-Lucas
Oncogene-targeted and immune checkpoint therapies have revolutionized the clinical management of malignant melanoma and now offer hope to patients with advanced disease. Intimately connected to patients’ overall clinical risk is whether the initial primary melanoma lesion will metastasize and cause advanced disease, but underlying mechanisms are not entirely understood. A subset of melanomas display heightened peroxisome proliferator–activated receptor γ coactivator 1-α (PGC1α) expression that maintains cell survival cues by promoting mitochondrial function, but also suppresses metastatic spread. Here, we show that PGC1α expression in melanoma cells was silenced by chromatin modifications that involve promoter H3K27 trimethylation. Pharmacological EZH2 inhibition diminished H3K27me3 histone markers, increased PGC1α expression, and functionally suppressed invasion within PGC1α-silenced melanoma cells. Mechanistically, PGC1α silencing activated transcription factor 12 (TCF12), to increase expression of WNT5A, which in turn stabilized YAP protein levels to promote melanoma migration and metastasis. Accordingly, inhibition of components of this transcription-signaling axis, including TCF12, WNT5A, or YAP, blocked melanoma migration in vitro and metastasis in vivo. These results indicate that epigenetic control of melanoma metastasis involved altered expression of PGC1α and an association with the inherent metabolic state of the tumor.
Chi Luo, Eduardo Balsa, Elizabeth A. Perry, Jiaxin Liang, Clint D. Tavares, Francisca Vazquez, Hans R. Widlund, Pere Puigserver
Foxp3+ T-regulatory (Treg) cells are key to immune homeostasis, but the contributions of various large, multiprotein complexes that regulate gene expression remain unexplored. We analyzed the role in Tregs of the evolutionarily conserved CoREST complex consisting of a scaffolding protein, Rcor1 or Rcor2, plus Hdac1 or Hdac2 and Lsd1 enzymes. Rcor1, Rcor2 and Lsd1 were physically associated with Foxp3, and mice with conditional deletion of Rcor1 in Foxp3+ Tregs had decreased proportions of Tregs in peripheral lymphoid tissues, and increased Treg expression of IL-2 and IFN-γ compared to WT cells. Mice with conditional deletion of the gene encoding Rcor1 in their Tregs had reduced suppression of homeostatic proliferation, inability to maintain long-term allograft survival despite costimulation blockade, and enhanced antitumor immunity in syngeneic models. Comparable findings were seen in WT mice treated with CoREST complex bivalent inhibitors, which also altered the phenotype of human Tregs and impaired their suppressive function. Our data point to the potential for therapeutic modulation of Treg functions by pharmacologic targeting of enzymatic components of the CoREST complex, and contribute to an understanding of the biochemical and molecular mechanisms by which Foxp3 represses large gene sets and maintains the unique properties of this key immune cell.
Yan Xiong, Liqing Wang, Eros Di Giorgio, Tatiana Akimova, Ulf H. Beier, Rongxiang Han, Matteo Trevisanut, Jay H. Kalin, Philip A. Cole, Wayne W. Hancock
Oncogenic KRAS is a major driver in lung adenocarcinoma (LUAD) that has yet to be therapeutically conquered. Here we report that the SLC7A11/glutathione axis displays metabolic synthetic lethality with oncogenic KRAS. Through metabolomics approaches, we found that mutationally activated KRAS strikingly increased the intracellular cystine level and glutathione biosynthesis. SLC7A11, a cystine/glutamate antiporter conferring specificity for cystine uptake, was overexpressed in patients with KRAS-mutant LUAD and showed positive association with tumor progression. Furthermore, SLC7A11 inhibition either by genetic depletion or pharmacological inhibition by sulfasalazine resulted in selective killing across a panel of KRAS-mutant cancer cells in vitro and tumor growth inhibition in vivo, suggesting the functionality and specificity of SLC7A11 as a therapeutic target. Importantly, we further identified a potent SLC7A11 inhibitor, HG106 that markedly decreased cystine uptake and intracellular glutathione biosynthesis. Furthermore, HG106 exhibited selective cytotoxicity towards KRAS-mutant cells by increasing oxidative stress- and endoplasmic reticulum stress-mediated cell apoptosis. Of note, treatment of KRAS-mutant LUAD with HG106 in several lung cancer preclinical mouse models led to marked tumor suppression and prolonged mouse survival. Overall, our findings reveal that KRAS-mutant LUAD cells are vulnerable to SLC7A11 inhibition, providing promising therapeutic approaches to the treatment of this currently incurable disease.
Kewen Hu, Kun Li, Jing Lv, Jie Feng, Jing Chen, Haigang Wu, Feixiong Cheng, Wenhao Jiang, Jieqiong Wang, Haixiang Pei, Paul J. Chiao, Zhenyu Cai, Yihua Chen, Mingyao Liu, Xiufeng Pang
Few therapies are currently available for patients with KRAS-driven cancers, highlighting the need to identify new molecular targets that modulate central downstream effector pathways. Here we found the miRNA cluster mir181ab1 as a key modulator of KRAS-driven oncogenesis. Ablation of Mir181ab1 in genetically-engineered mouse models of Kras-driven lung and pancreatic cancer was deleterious to tumor initiation and progression. Expression of both resident miRNAs in the Mir181ab1 cluster, miR181a1 and miR181b1, was necessary to rescue the Mir181ab1-loss phenotype underscoring their non-redundant role. In human cancer cells, depletion of miR181ab1 impaired proliferation and 3D growth, whereas overexpression provided a proliferative advantage. Lastly, we unveiled miR181ab1-regulated genes responsible for this phenotype. These studies identified what we believe to be a previously unknown role for miR181ab1 as a potential therapeutic target in two highly aggressive and difficult to treat KRAS-mutated cancers.
Karmele Valencia, Oihane Erice, Kaja Kostyrko, Simone Hausmann, Elizabeth Guruceaga, Anuradha Thathireddy, Natasha M. Flores, Leanne C. Sayles, Alex G. Lee, Rita Fragoso, Tian-Qiang Sun, Adrian Vallejo, Marta Roman, Rodrigo Entrialgo-Cadierno, Itziar Migueliz, Nerea Razquin, Puri Fortes, Fernando Lecanda, Jun Lu, Mariano Ponz-Sarvise, Chang-Zheng Chen, Pawel K. Mazur, E. Alejandro Sweet-Cordero, Silvestre Vicent
Genomics of primary prostate cancer differs from that of metastatic castration-resistant prostate cancer (mCRPC). We studied genomic aberrations in primary prostate cancer biopsies from patients who developed mCRPC, also studying matching, same patient, diagnostic and mCRPC biopsies following treatment. We profiled 470 treatment-naïve, prostate cancer diagnostic biopsies and for 61 cases, mCRPC biopsies using targeted and low-pass whole genome sequencing (n = 52). Descriptive statistics were used to summarize mutation and copy number profile. Prevalence was compared using Fisher's exact test. Survival correlations were studied using log-rank test. TP53 (27%) and PTEN (12%) and DDR gene defects (BRCA2 7%; CDK12 5%; ATM 4%) were commonly detected. TP53, BRCA2, and CDK12 mutations were significantly commoner than described in the TCGA cohort. Patients with RB1 loss in the primary tumour had a worse prognosis. Among 61 men with matched hormone-naïve and mCRPC biopsies, differences were identified in AR, TP53, RB1, and PI3K/AKT mutational status between same-patient samples. In conclusion, the genomics of diagnostic prostatic biopsies acquired from men who develop mCRPC differs to that of the primary prostatic cancers. RB1/TP53/AR aberrations are enriched in later stages, but the prevalence of DDR defects in diagnostic samples is similar to mCRPC.
Joaquin Mateo, George Seed, Claudia Bertan, Pasquale Rescigno, David Dolling, Ines Figueiredo, Susana Miranda, Daniel Nava Rodrigues, Bora Gurel, Matthew Clarke, Mark Atkin, Rob Chandler, Carlo Messina, Semini Sumanasuriya, Diletta Bianchini, Maialen Barrero, Antonella Petremolo, Zafeiris Zafeiriou, Mariane Sousa Fontes, Raquel Perez-Lopez, Nina Tunariu, Ben A. Fulton, Robert Jones, Ursula B. McGovern, Christy Ralph, Mohini Varughese, Omi Parikh, Suneil Jain, Tony Elliott, Shahneen Sandhu, Nuria Porta, Emma Hall, Wei Yuan, Suzanne Carreira, Johann S. de Bono
Recent findings have shown that inhibitors targeting BET (bromodomain and extraterminal domain) proteins, such as the small molecule JQ1, are potent growth inhibitors of many cancers and hold promise for cancer therapy. However, some reports also have revealed that JQ1 can activate additional oncogenic pathways and may affect EMT (epithelial mesenchymal transition). Therefore, it is important to address the potential unexpected effect of JQ1 treatment, such as cell invasion and metastasis. Here, we showed that in prostate cancer, JQ1 inhibited cancer cell growth but promoted invasion and metastasis in a BET protein independent manner. Multiple invasion pathways including EMT, BMP (bone morphogenetic protein) signaling, chemokine signaling and focal adhesion pathway were activated by JQ1 to promote invasion. Notably, JQ1 induced upregulation of invasion genes through inhibition of FOXA1, an invasion suppressor in prostate cancer. JQ1 directly interacted with FOXA1, inactivated FOXA1 binding to its interacting repressors, TLE3, HDAC7, and NFIC, thus blocking FOXA1 repressive function and activating the invasion genes. Our finding indicates that JQ1 has an unexpected effect of promoting invasion in prostate cancer. Thus, the ill effect of JQ1 or its derived therapeutic agents cannot be ignored during cancer treatment, especially in FOXA1 related cancers.
Leiming Wang, Mafei Xu, Chung-Yang Kao, Sophia Y. Tsai, Ming-Jer Tsai
The incidence of human papillomavirus (HPV)+ head and neck squamous cell carcinoma (HNSCC) has surpassed that of cervical cancer and is projected to increase rapidly until 2060. The co-evolution of HPV with transforming epithelial cells leads to the shutdown of host immune detection. Targeting proximal viral nucleic acid-sensing machinery is an evolutionarily conserved strategy among viruses to enable immune evasion. However, E7 from the dominant HPV subtype-16 in HNSCC shares low homology with HPV18 E7, which was shown to inhibit the STING-DNA-sensing pathway. The mechanisms by which HPV16 suppresses STING remain unknown. Recently, we characterized the role of the STING-type-I interferon (IFN-I) pathway in maintaining immunogenicity of HNSCC in mouse models. Here we extended those findings into clinical domain utilizing tissue microarrays and machine-learning-enhanced profiling of STING signatures with immune subsets. We additionally showed that HPV16 E7 employs distinct mechanisms than HPV18 E7 to antagonize the STING pathway. We identified NLRX1 as a critical intermediary partner to facilitate HPV16 E7-potentiated STING turnover. The depletion of NLRX1 resulted in significantly improved IFN-I-dependent T-cell infiltration profiles and tumor control. Overall, we discovered a unique HPV16 viral strategy to thwart host innate immune detection that can be further exploited to restore cancer immunogenicity.
Xiaobo Luo, Christopher R. Donnelly, Wang Gong, Blake R. Heath, Yuning Hao, Lorenza A. Donnelly, Toktam Moghbeli, Yee Sun Tan, Xin Lin, Emily Bellile, Benjamin A. Kansy, Thomas E. Carey, J. Chad Brenner, Lei Cheng, Peter J. Polverini, Meredith A. Morgan, Haitao Wen, Mark E. Prince, Robert L. Ferris, Yuying Xie, Simon Young, Gregory T. Wolf, Qianming Chen, Yu L. Lei
HSP27 is highly expressed in, and supports oncogene addiction of, many cancers. HSP27 phosphorylation is a limiting step for activation of this protein and a target for inhibition, but its highly disordered structure challenges rational structure-guided drug discovery. We performed multistep biochemical, structural, and computational experiments to define a spherical 24-monomer complex composed of 12 HSP27 dimers with a phosphorylation pocket flanked by serine residues between their N-terminal domains. Ivermectin directly binds this pocket to inhibit MAPKAP2-mediated HSP27 phosphorylation and depolymerization, thereby blocking HSP27-regulated survival signaling and client-oncoprotein interactions. Ivermectin potentiated activity of anti–androgen receptor and anti-EGFR drugs in prostate and EGFR/HER2-driven tumor models, respectively, identifying a repurposing approach for cotargeting stress-adaptive responses to overcome resistance to inhibitors of oncogenic pathway signaling.
Lucia Nappi, Adeleke H. Aguda, Nader Al Nakouzi, Barbara Lelj-Garolla, Eliana Beraldi, Nada Lallous, Marisa Thi, Susan Moore, Ladan Fazli, Dulguun Battsogt, Sophie Stoffeliene, Fuqiang Ban, Nham T. Nguyen, Neetu Saxena, Evgenia Dueva, Fan Zhang, Takeshi Yamazaki, Amina Zoubeidi, Artem Cherkasov, Gary D. Brayer, Martin Gleave