The E3 ubiquitin ligase RNF8 plays critical roles in maintaining genomic stability by promoting the repair of DNA double-strand breaks (DSBs) through ubiquitin signaling. Abnormal activation of Notch signaling and defective repair of DSBs promote breast cancer risk. Here, we found that low expression of the full-length RNF8 correlated with poor prognosis for breast cancer patients. Our data revealed that in addition to its role in the repair of DSBs, RNF8 regulated Notch1 signaling and cell-fate determination of mammary luminal progenitors. Mechanistically, RNF8 acted as a negative regulator of Notch signaling by ubiquitylating the active NOTCH1 protein (N1ICD), leading to its degradation. Consistent with abnormal activation of Notch signaling and impaired repair of DSBs in Rnf8-mutant mammary epithelial cells, we observed increased risk of mammary tumorigenesis in mouse models for RNF8 deficiency. Notably, deficiency of RNF8 sensitized breast cancer cells to combination of pharmacological inhibitors of Notch signaling and poly(ADP-ribose) polymerase (PARP), suggesting implications for treatment of breast cancer associated with impaired RNF8 expression or function.
Li Li, Kiran Kumar Naidu Guturi, Brandon Gautreau, Parasvi S. Patel, Amine Saad, Mayako Morii, Francesca Mateo, Luis Palomero, Haithem Barbour, Antonio Gomez, Deborah Ng, Max Kotlyar, Chiara Pastrello, Hartland W. Jackson, Rama Khokha, Igor Jurisica, El Bachir Affar, Brian Raught, Otto Sanchez, Moulay Alaoui-Jamali, Miguel A. Pujana, Anne Hakem, Razq Hakem
Breast cancer (BrCa) is the malignant tumor that most seriously threatens female health; however, the molecular mechanism underlying its progression remains unclear. Here, we found that conditional deletion of HIC1 in the mouse mammary gland might contribute to premalignant transformation in the early stage of tumor formation. Moreover, the chemokine CXCL14 secreted by HIC1-deleted BrCa cells bound to its novel cognate receptor GPR85 on mammary fibroblasts in the microenvironment and was responsible for activating these fibroblasts via the ERK1/2, Akt, and neddylation pathways, whereas the activated fibroblasts promoted BrCa progression via the induction of the epithelial–mesenchymal transition (EMT) by the CCL17/CCR4 axis. Finally, we confirmed that the HIC1-CXCL14-CCL17 loop was associated with the malignant progression of BrCa. Therefore, the crosstalk between HIC1-deleted BrCa cells and mammary fibroblasts might play a critical role in BrCa development. Taken together, exploring the progression of BrCa from the perspective of microenvironment will be beneficial for identifying the potential prognostic marker of breast tumor and providing the more effective treatment strategy.
Yingying Wang, Xiaoling Weng, Luoyang Wang, Mingang Hao, Yue Li, Lidan Hou, Yu Liang, Tianqi Wu, Mengfei Yao, Guowen Lin, Yiwei Jiang, Guohui Fu, Zhaoyuan Hou, Xiangjun Meng, Jinsong Lu, Jianhua Wang
Polyamine inhibition for cancer therapy is, conceptually, an attractive approach but has yet to meet success in the clinical setting. The aryl hydrocarbon receptor (AHR) is the central transcriptional regulator of the xenobiotic response. Our study revealed that AHR also positively regulates intracellular polyamine production via direct transcriptional activation of 2 genes, ODC1 and AZIN1, which are involved in polyamine biosynthesis and control, respectively. In patients with multiple myeloma (MM), AHR levels were inversely correlated with survival, suggesting that AHR inhibition may be beneficial for the treatment of this disease. We identified clofazimine (CLF), an FDA-approved anti-leprosy drug, as a potent AHR antagonist and a suppressor of polyamine biosynthesis. Experiments in a transgenic model of MM (Vk*Myc mice) and in immunocompromised mice bearing MM cell xenografts revealed high efficacy of CLF comparable to that of bortezomib, a first-in-class proteasome inhibitor used for the treatment of MM. This study identifies a previously unrecognized regulatory axis between AHR and polyamine metabolism and reveals CLF as an inhibitor of AHR and a potentially clinically relevant anti-MM agent.
Anna Bianchi-Smiraglia, Archis Bagati, Emily E. Fink, Hayley C. Affronti, Brittany C. Lipchick, Sudha Moparthy, Mark D. Long, Spencer R. Rosario, Shivana M. Lightman, Kalyana Moparthy, David W. Wolff, Dong Hyun Yun, Zhannan Han, Anthony Polechetti, Matthew V. Roll, Ilya I. Gitlin, Katerina I. Leonova, Aryn M. Rowsam, Eugene S. Kandel, Andrei V. Gudkov, P. Leif Bergsagel, Kelvin P. Lee, Dominic J. Smiraglia, Mikhail A. Nikiforov
Despite the success of T cell checkpoint blockade against melanoma, many “cold” tumors such as prostate cancer remain unresponsive. We find that hypoxic zones are prevalent across pre-clinical prostate cancer and resist T cell infiltration even in the context of CTLA-4 and PD-1 blockade. We show that the hypoxia-activated prodrug TH-302 reduces or eliminates hypoxia in these tumors. Combination therapy with this hypoxia-prodrug and checkpoint blockade cooperate to cure more than 80% of TRAMP-C2 prostate tumors. Immunofluorescence imaging shows that TH-302 drives an influx of T cells into hypoxic zones, which are then amplified by checkpoint blockade. Further, combination therapy reduces myeloid-derived suppressor cell density by more than 50%, and causes a persistent defect in the capacity of the tumor to replenish the granulocytic subset. Spontaneous prostate tumors in TRAMP transgenic mice, which are completely resistant to checkpoint blockade, show minimal adenocarcinoma tumor burden at 36 weeks of age and no evidence of neuroendocrine tumors. Survival of Pb-Cre4, Ptenpc−/−Smad4pc−/− mice with highly aggressive prostate adenocarcinoma is also significantly extended by the combination of hypoxia-prodrug and checkpoint blockade. This combination of hypoxia disruption and T cell checkpoint blockade may render some of the most therapeutically resistant cancers sensitive to immunotherapy.
Priyamvada Jayaprakash, Midan Ai, Arthur Liu, Pratha Budhani, Todd Bartkowiak, Jie Sheng, Casey R. Ager, Courtney Nicholas, Ashvin R. Jaiswal, Yanqiu Sun, Krishna Shah, Sadhana Balasubramanyam, Nan Li, Guocan Wang, Jing Ning, Anna Zal, Tomasz Zal, Michael A. Curran
Lysyl-tRNA synthetase (KRS) functions canonically in cytosolic translational processes. However, KRS is highly expressed in colon cancer, and localizes to distinct cellular compartments upon phosphorylations (i.e., the plasma membranes after T52-phosphorylation and the nucleus after S207-phosphorylation), leading to probably alternative non-canonical functions. It is unknown how other subcellular KRSs crosstalk with environmental cues during cancer progression. Here, we demonstrate that the KRS-dependent metastatic behavior of colon cancer spheroids within three-dimensional gels requires communication between cellular molecules and extracellular soluble factors and neighboring cells. Membranous and nuclear KRS were found to participate in invasive cell dissemination of colon cancer spheroids in three dimensional gels. Cancer spheroids secreted GAS6 via a KRS-dependent mechanism and caused the M2 polarization of macrophages, which activated the neighboring cells via secretion of FGF2/GROα/M-CSF to promote cancer dissemination under environmental remodeling via fibroblast-mediated laminins production. Analyses of tissues from clinical colon cancer patients and Krs–/+ animal models for cancer metastasis supported the roles of KRS, GAS6, and M2 macrophages in KRS-dependent positive feedback between tumors and environmental factors. Altogether, KRS in colon cancer cells remodels the microenvironment to promote metastasis, which can thus be therapeutically targeted at these bidirectional KRS-dependent communications of cancer spheroids with environmental cues.
Seo Hee Nam, Doyeun Kim, Doohyung Lee, Hye-Mi Lee, Dae-Geun Song, Jae Woo Jung, Ji Eon Kim, Hye-Jin Kim, Nam Hoon Kwon, Eun-Kyeong Jo, Sunghoon Kim, Jung Weon Lee
Central to the recognition, signaling, and repair of DNA double-strand breaks (DSBs) are the MRE11-RAD50-NBS1 (MRN) complex and mediator of DNA damage checkpoint protein 1 (MDC1), the interplay of which is essential for initiation and amplification of the DNA damage response (DDR). The intrinsic rule governing the regulation of the function of this molecular machinery remains to be investigated. We report here that the ubiquitin-specific protease USP7 was physically associated with the MRN-MDC1 complex and that the MRN-MDC1 complex acted as a platform for USP7 to efficiently deubiquitinate and stabilize MDC1, thereby sustaining the DDR. Accordingly, depletion of USP7 impaired the engagement of the MRN-MDC1 complex and the consequent recruitment of the downstream factors p53-binding protein 1 (53BP1) and breast cancer protein 1 (BRCA1) at DNA lesions. Significantly, USP7 was overexpressed in cervical cancer, and the level of its expression positively correlated with that of MDC1 and worse survival rates for patients with cervical cancer. We demonstrate that USP7-mediated MDC1 stabilization promoted cervical cancer cell survival and conferred cellular resistance to genotoxic insults. Together, our study reveals a role for USP7 in regulating the function of the MRN-MDC1 complex and activity of the DDR, supporting the pursuit of USP7 as a potential therapeutic target for MDC1-proficient cancers.
Dongxue Su, Shuai Ma, Lin Shan, Yue Wang, Yuejiao Wang, Cheng Cao, Beibei Liu, Chao Yang, Liyong Wang, Shanshan Tian, Xiang Ding, Xinhua Liu, Na Yu, Nan Song, Ling Liu, Shangda Yang, Qi Zhang, Fuquan Yang, Kai Zhang, Lei Shi
BACKGROUND. Understanding the integrated immunogenomic landscape of advanced prostate cancer (APC) could impact stratified treatment selection. METHODS. Defective mismatch repair (dMMR) status was determined by either loss of mismatch repair protein expression on IHC or microsatellite instability (MSI) by PCR in 127 APC biopsies from 124 patients (Royal Marsden [RMH] cohort); MSI by targeted panel next-generation sequencing (MSINGS) was then evaluated in the same cohort and in 254 APC samples from the Stand Up To Cancer/Prostate Cancer Foundation (SU2C/PCF). Whole exome sequencing (WES) data from this latter cohort were analyzed for pathogenic MMR gene variants, mutational load, and mutational signatures. Transcriptomic data, available for 168 samples, was also performed. RESULTS. Overall, 8.1% of patients in the RMH cohort had some evidence of dMMR, which associated with decreased overall survival. Higher MSINGS scores associated with dMMR, and these APCs were enriched for higher T cell infiltration and PD-L1 protein expression. Exome MSINGS scores strongly correlated with targeted panel MSINGS scores (r = 0.73, P < 0.0001), and higher MSINGS scores associated with dMMR mutational signatures in APC exomes. dMMR mutational signatures also associated with MMR gene mutations and increased immune cell, immune checkpoint, and T cell–associated transcripts. APC with dMMR mutational signatures overexpressed a variety of immune transcripts, including CD200R1, BTLA, PD-L1, PD-L2, ADORA2A, PIK3CG, and TIGIT. CONCLUSION. These data could impact immune target selection, combination therapeutic strategy selection, and selection of predictive biomarkers for immunotherapy in APC. FUNDING. We acknowledge funding support from Movember, Prostate Cancer UK, The Prostate Cancer Foundation, SU2C, and Cancer Research UK.
Daniel Nava Rodrigues, Pasquale Rescigno, David Liu, Wei Yuan, Suzanne Carreira, Maryou B. Lambros, George Seed, Joaquin Mateo, Ruth Riisnaes, Stephanie Mullane, Claire Margolis, Diana Miao, Susana Miranda, David Dolling, Matthew Clarke, Claudia Bertan, Mateus Crespo, Gunther Boysen, Ana Ferreira, Adam Sharp, Ines Figueiredo, Daniel Keliher, Saud Aldubayan, Kelly P. Burke, Semini Sumanasuriya, Mariane Sousa Fontes, Diletta Bianchini, Zafeiris Zafeiriou, Larissa Sena Teixeira Mendes, Kent Mouw, Michael T. Schweizer, Colin C. Pritchard, Stephen Salipante, Mary-Ellen Taplin, Himisha Beltran, Mark A. Rubin, Marcin Cieslik, Dan Robinson, Elizabeth Heath, Nikolaus Schultz, Joshua Armenia, Wassim Abida, Howard Scher, Christopher Lord, Alan D’Andrea, Charles L. Sawyers, Arul M. Chinnaiyan, Andrea Alimonti, Peter S. Nelson, Charles G. Drake, Eliezer M. Van Allen, Johann S. de Bono
The host immune system plays a pivotal role in the emergence of tumor cells that are refractory to multiple clinical interventions including immunotherapy, chemotherapy, and radiotherapy. Here, we examined the molecular mechanisms by which the immune system triggers cross-resistance to these interventions. By examining the biological changes in murine and tumor cells subjected to sequential rounds of in vitro or in vivo immune selection via cognate cytotoxic T lymphocytes, we found that multimodality resistance arises through a core metabolic reprogramming pathway instigated by epigenetic loss of the ATP synthase subunit ATP5H, which leads to ROS accumulation and HIF-1α stabilization under normoxia. Furthermore, this pathway confers to tumor cells a stem-like and invasive phenotype. In vivo delivery of antioxidants reverses these phenotypic changes and resensitizes tumor cells to therapy. ATP5H loss in the tumor is strongly linked to failure of therapy, disease progression, and poor survival in patients with cancer. Collectively, our results reveal a mechanism underlying immune-driven multimodality resistance to cancer therapy and demonstrate that rational targeting of mitochondrial metabolic reprogramming in tumor cells may overcome this resistance. We believe these results hold important implications for the clinical management of cancer.
Kwon-Ho Song, Jae-Hoon Kim, Young-Ho Lee, Hyun Cheol Bae, Hyo-Jung Lee, Seon Rang Woo, Se Jin Oh, Kyung-Mi Lee, Cassian Yee, Bo Wook Kim, Hanbyoul Cho, Eun Joo Chung, Joon-Yong Chung, Stephen M. Hewitt, Tae-Wook Chung, Ki-Tae Ha, Young-Ki Bae, Chih-Ping Mao, Andrew Yang, T.C. Wu, Tae Woo Kim
Tumor relapse is the leading cause of death in breast cancer, largely due to the fact that recurrent tumors are frequently resistant to chemotherapy. We previously reported that downregulation of the proapoptotic protein Par-4 promotes tumor recurrence in genetically engineered mouse models of breast cancer recurrence. In the present study, we examined the mechanism and functional significance of Par-4 downregulation in recurrent tumors. We found that epithelial-to-mesenchymal transition (EMT) promotes epigenetic silencing of Par-4 in recurrent tumors. Par-4 silencing proceeded through binding of the EMT transcription factor Twist to the Par-4 promoter, where Twist induced a unique bivalent chromatin domain. This bivalent configuration conferred plasticity at the Par-4 promoter, and Par-4 silencing could be reversed with pharmacologic inhibitors of Ezh2 and HDAC1/2. Using an epigenome editing approach to reexpress Par-4 by specifically reversing the histone modifications found in recurrent tumors, we found that Par-4 reexpression sensitized recurrent tumors to chemotherapy in vitro and in vivo. Upon reexpression, Par-4 bound to the protein phosphatase PP1, caused widespread changes in phosphorylation of cytoskeletal proteins, and cooperated with microtubule-targeting drugs to induce mitotic defects. These results identify Twist-induced epigenetic silencing of Par-4 as a targetable axis that promotes chemoresistance in recurrent breast cancer.
Nathaniel W. Mabe, Douglas B. Fox, Ryan Lupo, Amy E. Decker, Stephanie N. Phelps, J. Will Thompson, James V. Alvarez
Human endogenous retroviruses (hERVs) are remnants of exogenous retroviruses that have integrated into the genome throughout evolution. We developed a computational workflow, hervQuant, which identified over 3,000 transcriptionally active hERVs within The Cancer Genome Atlas (TCGA) pan-cancer RNA-seq database. hERV expression was associated with clinical prognosis in several tumor types, most significantly clear cell renal cell carcinoma (ccRCC). We explored two mechanisms by which hERV expression may influence the tumor-immune microenvironment in ccRCC: through 1) RIG-I-like signaling, and 2) retroviral antigen activation of adaptive immunity. We demonstrated the ability of hERV signatures associated with these immune mechanisms to predict patient survival in ccRCC, independent of clinical staging and molecular subtyping. We identified potential tumor-specific hERV epitopes with evidence of translational activity through the use of a ccRCC Ribo-seq dataset, validated their ability to bind HLA in vitro, and identified presence of MHC tetramer-positive T cells against predicted epitopes. hERV sequences identified through this screening approach were significantly more highly expressed in ccRCC tumors responsive to treatment with programmed death receptor-1 (PD-1) inhibition. hervQuant provides new insights into the role of hERVs within the tumor-immune microenvironment as well as evidence for hERV expression-based biomarkers for patient prognosis and response to immunotherapy.
Christof C. Smith, Kathryn E. Beckermann, Dante S. Bortone, Aguirre A. de Cubas, Lisa M. Bixby, Samuel J. Lee, Anshuman Panda, Shridar Ganesan, Gyan Bhanot, Eric M. Wallen, Matthew I. Milowsky, William Y. Kim, W. Kimryn Rathmell, Ronald Swanstrom, Joel S. Parker, Jonathan S. Serody, Sara R. Selitsky, Benjamin G. Vincent