Acute megakaryoblastic leukemia of Down syndrome (DS-AMKL) is a model of clonal evolution from a preleukemic transient myeloproliferative disorder requiring both a trisomy 21 (T21) and a GATA1s mutation to a leukemia driven by additional driver mutations. We modelled the megakaryocyte differentiation defect through stepwise gene editing of GATA1s, SMC3+/- and MPLW515K providing 20 different trisomy or disomy 21 iPSC clones. GATA1s profoundly reshaped iPSC-derived hematopoietic architecture with gradual myeloid-to-megakaryocyte shift and megakaryocyte differentiation alteration upon addition of SMC3 and MPL mutations. Transcriptional, chromatin accessibility and GATA1 binding data showed alteration of essential megakaryocyte differentiation genes, including NFE2 downregulation that was associated with loss of GATA1s binding and functionally-involved in megakaryocyte differentiation blockage. T21 enhanced the proliferative phenotype reproducing the cellular and molecular abnormalities of DS-AMKL. Our study provides a unique array of human cell-based models revealing individual contributions of different mutations to DS-AMKL differentiation blockage, a major determinant of leukemic progression.
Brahim Arkoun, Elie Robert, Fabien Boudia, Stefania Mazzi, Virginie Dufour, Aurelie Siret, Yasmine Mammasse, Zakia Aid, Mathieu Vieira, Aygun Imanci, Marine Aglave, Marie Cambot, Rachel Petermann, Sylvie Souquere, Philippe Rameau, Cyril Catelain, Romain Diot, Gerard Tachdjian, Olivier Hermine, Nathalie Droin, Najet Debili, Isabelle Plo, Sebastien Malinge, Eric Soler, Hana Raslova, Thomas Mercher, William Vainchenker
Molecularly targeted cancer therapy has improved outcomes for cancer patients with targetable oncoproteins, such as mutant epidermal growth factor receptor (EGFR) in lung cancer. Yet, long-term patient survival remains limited because treatment responses are typically incomplete. One potential explanation for the lack of complete and durable responses is that oncogene-driven cancers with activating mutations in the EGFR often harbor additional co-occurring genetic alterations. This hypothesis remains untested for most genetic alterations that co-occur with mutant EGFR. Here, we report the functional impact of inactivating genetic alteration of the mRNA splicing factor RBM10 that co-occur with mutant EGFR. RBM10 deficiency decreased EGFR inhibitor efficacy in patient-derived EGFR mutant tumor models. RBM10 modulated mRNA alternative splicing of the mitochondrial apoptotic regulator Bcl-x to regulate tumor cell apoptosis during treatment. Genetic inactivation of RBM10 diminished EGFR inhibitor-mediated apoptosis by decreasing the ratio of Bcl-xS-(pro-apoptotic)-to-Bcl-xL(anti-apoptotic) Bcl-x isoforms. RBM10 deficiency was a biomarker of poor response to EGFR inhibitor treatment in clinical samples. Co-inhibition of Bcl-xL and mutant EGFR overcame resistance induced by RBM10 deficiency. This study sheds light on the role of co-occurring genetic alterations, and on the impact of splicing factor deficiency in the modulation of sensitivity to targeted kinase inhibitor cancer therapy.
Shigeki Nanjo, Wei Wu, Niki Karachaliou, Collin M. Blakely, Junji Suzuki, Yu-Ting Chou, Siraj M. Ali, D. Lucas Kerr, Victor R. Olivas, Jonathan Shue, Julia Rotow, Manasi K. Mayekar, Franziska Haderk, Nilanjana Chatterjee, Anatoly Urisman, Jia Chi Yeo, Anders J. Skanderup, Aaron C. Tan, Wai Leong Tam, Oscar Arrieta, Kazuyoshi Hosomichi, Akihiro Nishiyama, Seiji Yano, Yuriy Kirichok, Daniel S.W. Tan, Rafael Rosell, Ross A. Okimoto, Trever G. Bivona
Lymph node (LN) metastasis occurs frequently in pancreatic ductal adenocarcinoma (PDAC) and predicts poor prognosis for patients. The KRASG12D mutation confers an aggressive PDAC phenotype that is susceptible to lymphatic dissemination. However, the regulatory mechanism underlying KRASG12D mutation-driven LN metastasis in PDAC remains unclear. Herein, we identified that PDAC with KRASG12D mutation (KRASG12D PDAC) sustained extracellular vesicle (EV)-mediated transmission of hnRNPA1 in a SUMOylation-dependent manner and promoted lymphangiogenesis and LN metastasis in vitro and in vivo. Mechanistically, hnRNPA1 bound with SUMO2 at the lysine 113 residue via KRASG12D-induced hyperactivation of SUMOylation, which enabled its interaction with TSG101 to enhance hnRNPA1 packaging and transmission via EVs. Subsequently, SUMOylation induced EV-packaged hnRNPA1 anchoring to the adenylate and uridylate-rich elements of PROX1 in lymphatic endothelial cells, thus stabilizing PROX1 mRNA. Importantly, impeding SUMOylation of EV-packaged hnRNPA1 dramatically inhibited LN metastasis of KRASG12D PDAC in a genetically engineered KrasG12D/+; Trp53R172H/+; Pdx-1-Cre (KPC) mice model. Our findings highlight the mechanism by which KRAS mutant-driven SUMOylation triggers EV-packaged hnRNPA1 transmission to promote lymphangiogenesis and LN metastasis, shedding light on the potential application of hnRNPA1 as a therapeutic target in patients with KRASG12D PDAC.
Yuming Luo, Zhihua Li, Yao Kong, Wang He, Hanhao Zheng, Mingjie An, Yan Lin, Dingwen Zhang, Jiabin Yang, Yue Zhao, Changhao Chen, Rufu Chen
Wnt signaling regulates the balance between stemness and differentiation in multiple tissues and in cancer. RNF43-mutant pancreatic cancers are dependent on Wnt production, and pharmacologic blockade of the pathway, e.g., by PORCN inhibitors, leads to tumor differentiation. However, primary resistance to these inhibitors has been observed. To elucidate potential mechanisms, we performed in vivo CRISPR screens in PORCN inhibitor-sensitive RNF43-mutant pancreatic cancer xenografts. As expected, genes in the Wnt pathway whose loss conferred drug resistance were identified, including APC, AXIN1, and CTNNBIP1. Unexpectedly, the screen also identified the histone acetyltransferase EP300 (p300), but not its paralog CREBBP (CBP). We found that EP300 is silenced due to genetic alterations in all the existing RNF43-mutant pancreatic cancer cell lines that are resistant to PORCN inhibitors. Mechanistically, loss of EP300 directly down-regulated GATA6 expression, thereby silencing the GATA6-regulated differentiation program and leading to a phenotypic transition from the classical subtype to the dedifferentiated basal-like/squamous subtype of pancreatic cancer. EP300 mutation and loss of GATA6 function bypassed the anti-differentiation activity of Wnt signaling, rendering these cancer cells resistant to Wnt inhibition.
Zheng Zhong, Nathan Harmston, Kris C. Wood, Babita Madan, David M. Virshup
Patients with high-risk non muscle-invasive bladder cancer (NMIBC) frequently relapse after standard intravesical BCG therapy and may have a dismal outcome. Resistance mechanisms to such immunotherapy remain misunderstood. Here, using cancer cell lines, freshly resected human bladder tumors and cohorts of bladder cancer patients pre- and post-BCG therapy, we demonstrate two distinct patterns of immune subversion upon BCG relapse. In the first pattern, intracellular BCG infection of cancer cells induced a post-transcriptional downregulation of HLA-I membrane expression via an inhibition of the autophagy flux. Patients with HLA-I deficient cancer cells post-BCG therapy displayed a myeloid immunosuppressive tumor microenvironment with epithelial-to-mesenchymal transition (EMT) characteristics and dismal outcomes. Conversely, patients with HLA-I proficient cancer cells post-BCG therapy presented with CD8+ T cell tumor infiltrates, upregulation of inflammatory cytokines and inhibitory immune checkpoint molecules. Those patients had a very favorable outcome. We surmise that HLA-I expression in bladder cancers at relapse post-BCG does not result from immunoediting but rather from an immune subversion process directly induced by BCG on cancer cells, which predicts dismal prognosis. Cancer cells HLA-I scoring by immunohistochemistry (IHC) staining can be easily implemented by pathologists in routine practice in order to stratify future urothelial cancer patient treatment strategies.
Mathieu Rouanne, Julien Adam, Camélia Radulescu, Diane Letourneur, Delphine Bredel, Severine Mouraud, Anne-Gaelle Goubet, Marion Leduc, Noah Chen, Tuan Zea Tan, Nicolas Signolle, Amélie E. Bigorgne, Michael Dussiot, Lambros Tselikas, Sandrine Susini, François-Xavier Danlos, Anna K. Schneider, Roman M. Chabanon, Sophie Vacher, Ivan Bièche, Thierry Lebret, Yves Allory, Jean-Charles Soria, Nicholas Arpaia, Guido Kroemer, Oliver Kepp, Jean Paul Thiery, Laurence Zitvogel, Aurélien Marabelle
Hepatocellular carcinoma (HCC) is a major cause of cancer mortality worldwide and available therapies, including immunotherapies, are ineffective for many patients. HCC is characterized by intratumoral hypoxia, and increased expression of hypoxia-inducible factor 1α (HIF-1α) in diagnostic biopsies is associated with patient mortality. Here we report the development of 32-134D, a low-molecular-weight compound that effectively inhibits gene expression mediated by HIF-1 and HIF-2 in HCC cells, and blocks human and mouse HCC tumor growth. In immunocompetent mice bearing Hepa1-6 HCC tumors, addition of 32-134D to anti-PD1 therapy increased the rate of tumor eradication from 25% to 67%. Treated mice showed no changes in appearance, behavior, body weight, hemoglobin, or hematocrit. Compound 32-134D altered the expression of a large battery of genes encoding proteins that mediate angiogenesis, glycolytic metabolism, and responses to innate and adaptive immunity. This altered gene expression led to significant changes in the tumor immune microenvironment, including a decreased percentage of tumor-associated macrophages and myeloid-derived suppressor cells, which mediate immune evasion, and an increased percentage of CD8+ T cells and natural killer cells, which mediate antitumor immunity. Taken together, these preclinical findings suggest that combining 32-134D with immune checkpoint blockade may represent a breakthrough therapy for HCC.
Shaima Salman, David J. Meyers, Elizabeth E. Wicks, Sophia N. Lee, Emmanuel Datan, Aline M. Thomas, Nicole M. Anders, Yousang Hwang, Yajing Lyu, Yongkang Yang, Walter Jackson III, Dominic Dordai, Michelle A. Rudek, Gregg L. Semenza
Activated SUMOylation is a hallmark of cancer. Starting from a targeted screening for SUMO-regulated immune evasion mechanisms, we identified an evolutionarily conserved function of activated SUMOylation, which attenuated the immunogenicity of tumor cells. Activated SUMOylation allowed cancer cells to evade CD8+ T cell–mediated immunosurveillance by suppressing the MHC class I (MHC-I) antigen-processing and presentation machinery (APM). Loss of the MHC-I APM is a frequent cause of resistance to cancer immunotherapies, and the pharmacological inhibition of SUMOylation (SUMOi) resulted in reduced activity of the transcriptional repressor scaffold attachment factor B (SAFB) and induction of the MHC-I APM. Consequently, SUMOi enhanced the presentation of antigens and the susceptibility of tumor cells to CD8+ T cell–mediated killing. Importantly, SUMOi also triggered the activation of CD8+ T cells and thereby drove a feed-forward loop amplifying the specific antitumor immune response. In summary, we showed that activated SUMOylation allowed tumor cells to evade antitumor immunosurveillance, and we have expanded the understanding of SUMOi as a rational therapeutic strategy for enhancing the efficacy of cancer immunotherapies.
Uta M. Demel, Marlitt Böger, Schayan Yousefian, Corinna Grunert, Le Zhang, Paul W. Hotz, Adrian Gottschlich, Hazal Köse, Konstandina Isaakidis, Dominik Vonficht, Florian Grünschläger, Elena Rohleder, Kristina Wagner, Judith Dönig, Veronika Igl, Bernadette Brzezicha, Francis Baumgartner, Stefan Habringer, Jens Löber, Björn Chapuy, Carl Weidinger, Sebastian Kobold, Simon Haas, Antonia B. Busse, Stefan Müller, Matthias Wirth, Markus Schick, Ulrich Keller
CD4 T helper (Th) cells play a key role in orchestrating immune responses, but the identity of the CD4 Th cells involved in the anti-tumor immune response remains to be defined. We analyzed the immune cell infiltrates of head and neck squamous cell carcinoma and colorectal cancers and identified a subset of CD4 Th cells distinct from FOXP3+ regulatory T cells that co-express PD-1 and ICOS. These tumor-infiltrating CD4 Th cells (CD4 Th TIL) have a tissue-resident memory phenotype, are present in MHC class II-rich areas and proliferate in the tumor suggesting local antigen recognition. The T-cell receptor repertoire of the PD-1+ICOS+ CD4 Th TIL is oligoclonal, with T-cell clones expanded in the tumor, but present at low frequencies in the periphery. Finally, these PD-1+ICOS+ CD4 Th TIL were shown to recognize both tumor-associated antigens and tumor-specific neoantigens. Our findings provide an approach for isolating tumor-reactive CD4 Th TIL directly ex vivo that will help define their role in the anti-tumor immune response and potentially improve future adoptive T-cell therapy approaches.
Rebekka Duhen, Olivier Fesneau, Kimberly A. Samson, Alexandra K. Frye, Michael Beymer, Venkatesh Rajamanickam, David Ross, Eric Tran, Brady Bernard, Andrew D. Weinberg, Thomas Duhen
Myeloproliferative neoplasms (MPNs) are associated with significant alterations in the bone marrow microenvironment that include decreased expression of key niche factors and myelofibrosis. Here, we explore the contribution of TGF-β to these alterations by abrogating TGF-β signaling in bone marrow mesenchymal stromal cells. Loss of TGF-β signaling in Osx-Cre-targeted MSCs prevents the development of myelofibrosis in both MPLW515L and Jak2V617F models of MPNs. In contrast, despite the absence of myelofibrosis, loss of TGF-β signaling in mesenchymal stromal cells does not rescue the defective hematopoietic niche induced by MPLW515L, as evidenced by decreased bone marrow cellularity, hematopoietic stem/progenitor cell number, and Cxcl12 and Kitlg expression and the presence of splenic extramedullary hematopoiesis. Induction of myelofibrosis by MPLW515L was intact in Osx-Cre; Smad4f/f recipients, demonstrating that SMAD4-independent TGF-β signaling mediates the myelofibrosis phenotype. Indeed, treatment with a c-Jun N-terminal kinase (JNK) inhibitor prevents the development of myelofibrosis induced by MPLW515L. Together, these data show that JNK-dependent TGF-β signaling in mesenchymal stromal cells is responsible for the development of myelofibrosis but not hematopoietic niche disruption in MPNs, suggesting that the signals that regulate niche gene expression in bone marrow mesenchymal stromal cells are distinct from those that induce a fibrogenic program.
Juo-Chin Yao, Karolyn A. Oetjen, Tianjiao Wang, Haoliang Xu, Grazia Abou-Ezzi, Joseph R. Krambs, Salil Uttarwar, Eric J. Duncavage, Daniel C. Link
PRAME is a prominent member of the cancer germline antigen family of proteins, which triggers autologous T-cell mediated immune responses. Integrative genomic analysis in diffuse large B-cell lymphoma (DLBCL) uncovered recurrent, and highly focal deletions of 22q11.22 including the PRAME gene, which were associated with poor outcome. PRAME-deleted tumors showed cytotoxic T-cell immune escape and were associated with cold tumor microenvironments. In addition, PRAME down-modulation was strongly associated with somatic EZH2 Y641 mutations in DLBCL. In turn, PRC2-regulated genes were repressed in isogenic PRAME KO lymphoma cell lines and PRAME was found to directly interact with EZH2 as a negative regulator. EZH2 inhibition with EPZ-6438 abrogated these extrinsic and intrinsic effects leading to PRAME expression and microenvironment restoration in vivo. Our data highlight multiple functions of PRAME during lymphomagenesis, and provide a preclinical rationale for synergistic therapies combining epigenetic re-programming with PRAME-targeted therapies.
Katsuyoshi Takata, Lauren C. Chong, Daisuke Ennishi, Tomohiro Aoki, Michael Yu Li, Avinash Thakur, Shannon Healy, Elena Viganò, Tao Dao, Daniel Kwon, Gerben Duns, Julie S. Nielsen, Susana Ben-Neriah, Ethan Tse, Stacy S. Hung, Merrill Boyle, Sung Soo Mun, Christopher M. Bourne, Bruce Woolcock, Adèle H. Telenius, Makoto Kishida, Shinya Rai, Allen W. Zhang, Ali Bashashati, Saeed Saberi, Gianluca D' Antonio, Brad H. Nelson, Sohrab P. Shah, Pamela A. Hoodless, Ari M. Melnick, Randy D. Gascoyne, Joseph M. Connors, David A. Scheinberg, Wendy Béguelin, David W. Scott, Christian Steidl