Genetic alterations in the RUNX1 gene are associated with benign and malignant blood disorders, particularly of megakaryocyte and myeloid lineages. The role of RUNX1 in acute lymphoblastic leukemia (ALL) is less clear, particularly how germline genetic variation influences the predisposition to this type of leukemia. Sequencing 4,836 children with B-ALL and 1,354 cases of T-ALL, we identified 31 and 18 germline RUNX1 variants, respectively. RUNX1 variants in B-ALL consistently showed minimal damaging effects. By contrast, 6 T-ALL-related variants result in drastic loss of RUNX1 activity as a transcription activator in vitro. Ectopic expression of dominant-negative RUNX1 variants in human CD34+ cells repressed differentiation into erythroid, megakaryocytes, and T cells, while promoting myeloid cell development. Chromatin immunoprecipitation sequencing of T-ALL models showed distinctive patterns of RUNX1 binding by variant proteins. Further whole genome sequencing identified JAK3 mutation as the most frequent somatic genomic abnormality in T-ALL with germline RUNX1 variants. Co-introduction of RUNX1 variant and JAK3 mutation in hematopoietic stem and progenitor cells in mice gave rise to T-ALL with early T-cell precursor phenotype. Taken together, these results indicated that RUNX1 is an important predisposition gene for T-ALL and pointed to novel biology of RUNX1-mediated leukemogenesis in the lymphoid lineages.
Yizhen Li, Wentao Yang, Meenakshi Devidas, Stuart S. Winter, Chimene Kesserwan, Wenjian Yang, Kimberly P. Dunsmore, Colton Smith, Maoxiang Qian, Xujie Zhao, Ranran Zhang, Julie M. Gastier-Foster, Elizabeth A. Raetz, William L. Carroll, Chunliang Li, Paul P. Liu, Karen R. Rabin, Takaomi Sanda, Charles G. Mullighan, Kim E. Nichols, William E. Evans, Ching-Hon Pui, Stephen P. Hunger, David T. Teachey, Mary V. Relling, Mignon L. Loh, Jun J. Yang
The 12q13-q14 chromosomal region is recurrently amplified in 25% of fusion-positive (FP) rhabdomyosarcoma (RMS) cases and is associated with a poor prognosis. To identify amplified oncogenes in FP RMS, we compared the size, gene composition and expression of 12q13-q14 amplicons in FP RMS with other cancer categories (glioblastoma multiforme, lung adenocarcinoma and liposarcoma) in which 12q13-q14 amplification frequently occurs. We uncovered a 0.2 Mb region that is commonly amplified across these cancers and includes CDK4 and six other genes that are overexpressed in amplicon-positive samples. Additionally, we identified a 0.5 Mb segment that is only recurrently amplified in FP RMS and includes four genes that are overexpressed in amplicon-positive RMS. Among these genes, only SHMT2 was overexpressed at the protein level in an amplicon-positive RMS cell line. SHMT2 knockdown in amplicon- positive RMS cells suppressed growth, transformation and tumorigenesis, whereas overexpression in amplicon-negative RMS cells promoted these phenotypes. High SHMT2 expression reduced sensitivity of FP RMS cells to SHIN1, a direct SHMT2 inhibitor, but sensitized cells to pemetrexed, an inhibitor of the folate cycle. In conclusion, our study demonstrated that SHMT2 contributes to tumorigenesis in FP RMS and that SHMT2 amplification predicts differential response to drugs targeting this metabolic pathway.
Thanh H. Nguyen, Prasantha L. Vemu, Gregory E. Hoy, Salah Boudjadi, Bishwanath Chatterjee, Jack F. Shern, Javed Khan, Wenyue Sun, Frederic G. Barr
Clear Cell Sarcoma (CCS) is a deadly malignancy affecting adolescents and young adults. It is characterized by reciprocal translocations resulting in the expression of the chimeric EWSR1-ATF1 or EWSR1-CREB1 fusion proteins, driving sarcomagenesis. Besides these characteristics, CCS has remained genomically uncharacterized. Copy number analysis of human CCSs showed frequent amplifications of the MITF locus and chromosomes 7 and 8. Few alterations were shared with Ewing sarcoma or desmoplastic small round cell tumors, other EWSR1-rearranged tumors. Exome sequencing in mouse tumors generated by expressing EWSR1-ATF1 from the Rosa26 locus demonstrated no other repeated pathogenic variants. Additionally, we generated a new CCS mouse by Cre-loxP-induced chromosomal translocation between Ewsr1 and Atf1, resulting in copy number loss of chromosome 6 and chromosome 15 instability, including amplification of a portion syntenic with human chromosome 8, surrounding Myc. Additional experiments in the Rosa26 conditional model demonstrated that Mitf or Myc can contribute to sarcomagenesis. Copy number observations in human tumors and genetic experiments in mice render, for the first time, a functional landscape of the CCS genome. These data advance efforts to understand the biology of CCS with innovative models, in which we can eventually validate preclinical therapies, necessary to move toward longer and better survival of the young victims of this disease.
Emanuele Panza, Benjamin B. Ozenberger, Krystal M. Straessler, Jared J. Barrott, Li Li, Yanliang Wang, Mingchao Xie, Anne Boulet, Simon W. A. Titen, Clinton C. Mason, Alexander J. Lazar, Li Ding, Mario R. Capecchi, Kevin B. Jones
Cancer cells reprogram lipid metabolism during their malignant progression, but limited information is currently available on the involvement of alterations in fatty acid synthesis in cancer development. We herein demonstrate that acetyl-CoA carboxylase 1 (ACC1), a rate-limiting enzyme for fatty acid synthesis, plays a critical role in regulating the growth and differentiation of leukemia-initiating cells. The Trib1-COP1 complex is an E3 ubiquitin ligase that targets C/EBPA, a transcription factor regulating myeloid differentiation, for degradation, and its overexpression specifically induces acute myeloid leukemia (AML). We identified ACC1 as a target of the Trib1-COP1 complex and found that an ACC1 mutant resistant to degradation because of the lack of a Trib1-binding site attenuated complex-driven leukemogenesis. Stable ACC1 protein expression suppressed the growth-promoting activity and increased ROS levels with the consumption of NADPH in a primary bone marrow culture, and delayed the onset of AML with increases in mature myeloid cells in mouse models. ACC1 promoted the terminal differentiation of Trib1-COP1–expressing cells and eradicated leukemia-initiating cells in the early phase of leukemic progression. These results indicate that ACC1 is a natural inhibitor of AML development. The upregulated expression of the ACC1 protein has potential as an effective strategy for cancer therapy.
Hidenori Ito, Ikuko Nakamae, Jun-ya Kato, Noriko Yoneda-Kato
Phoebe Carter, Ulrike Schnell, Christopher Chaney, Betty Tong, Xinchao Pan, Jianhua Ye, Glenda Mernaugh, Jennifer L. Cotton, Vitaly Margulis, Junhao Mao, Roy Zent, Bret M. Evers, Payal Kapur, Thomas J. Carroll
Hypoxia, a hallmark feature of the tumor microenvironment, causes resistance to conventional chemotherapy, but was recently reported to synergize with poly(ADP-ribose) polymerase inhibitors (PARPis) in homologous recombination–proficient (HR-proficient) cells through suppression of HR. While this synergistic killing occurs under severe hypoxia (<0.5% oxygen), our study shows that moderate hypoxia (2% oxygen) instead promotes PARPi resistance in both HR-proficient and -deficient cancer cells. Mechanistically, we identify reduced ROS-induced DNA damage as the cause for the observed resistance. To determine the contribution of hypoxia to PARPi resistance in tumors, we used the hypoxic cytotoxin tirapazamine to selectively kill hypoxic tumor cells. We found that the selective elimination of hypoxic tumor cells led to a substantial antitumor response when used with PARPi compared with that in tumors treated with PARPi alone, without enhancing normal tissue toxicity. Since human breast cancers with BRAC1/2 mutations have an increased hypoxia signature and hypoxia reduces the efficacy of PARPi, then eliminating hypoxic tumor cells should enhance the efficacy of PARPi therapy.
Manal Mehibel, Yu Xu, Caiyun G. Li, Eui Jung Moon, Kaushik N. Thakkar, Anh N. Diep, Ryan K. Kim, Joshua D. Bloomstein, Yiren Xiao, Julien Bacal, Joshua C. Saldivar, Quynh-Thu Le, Karlene A. Cimprich, Erinn B. Rankin, Amato J. Giaccia
BACKGROUND Molecular characterization of prostate cancer (PCa) has revealed distinct subclasses based on underlying genomic alterations occurring early in the natural history of the disease. However, how these early alterations influence subsequent molecular events and the course of the disease over its long natural history remains unclear.METHODS We explored the molecular and clinical progression of different genomic subtypes of PCa using distinct tumor lineage models based on human genomic and transcriptomic data. We developed transcriptional classifiers, and defined “early” and “late” categories of molecular subclasses from 8,158 PCa patients. Molecular subclasses were correlated with clinical outcomes and pathologic characteristics using Kaplan-Meier and logistic regression analyses.RESULTS We identified PTEN and CHD1 alterations as subtype-specific late progression events specifically in ERG-overexpressing (ERG+) and SPOP-mutant tumors, respectively, and 2 distinct progression models consisting of ERG/PTEN (normal to ERG+ to PTEN-deleted) and SPOP/CHD1 (normal to SPOP-mutated to CHD1-deleted) with shared early tumorigenesis but distinct pathways toward progression. We found that within ERG+ and SPOP-mutant subtypes, late events were associated with worse prognosis. Importantly, the clinical and pathologic features associated with distinct late events at radical prostatectomy were strikingly different; PTEN deletions were associated with increased locoregional stage, while CHD1 deletions were only associated with increased grade, despite equivalent metastatic potential.CONCLUSION These findings suggest a paradigm in which specific subtypes of PCa follow distinct pathways of progression, at both the molecular and clinical levels. Therefore, the interpretation of common clinical parameters such as locoregional tumor stage may be influenced by the underlying tumor lineage, and potentially influence management decisions.FUNDING Prostate Cancer Foundation, National Cancer Institute, Urology Care Foundation, Damon Runyon Cancer Research Foundation, US Department of Defense, and the AIRC Foundation.
Deli Liu, Michael A. Augello, Ivana Grbesa, Davide Prandi, Yang Liu, Jonathan E. Shoag, R. Jeffrey Karnes, Bruce J. Trock, Eric A. Klein, Robert B. Den, Francesca Demichelis, Elai Davicioni, Andrea Sboner, Christopher E. Barbieri
Intercellular biomolecule transfer (ICBT) between malignant and benign cells is a major driver of tumor growth, resistance to anticancer therapies, and therapy-triggered metastatic disease. Here we characterized cholesterol 25-hydroxylase (CH25H) as a key genetic suppressor of ICBT between malignant and endothelial cells (ECs) and of ICBT-driven angiopoietin-2–dependent activation of ECs, stimulation of intratumoral angiogenesis, and tumor growth. Human CH25H was downregulated in the ECs from patients with colorectal cancer and the low levels of stromal CH25H were associated with a poor disease outcome. Knockout of endothelial CH25H stimulated angiogenesis and tumor growth in mice. Pharmacologic inhibition of ICBT by reserpine compensated for CH25H loss, elicited angiostatic effects (alone or combined with sunitinib), augmented the therapeutic effect of radio-/chemotherapy, and prevented metastatic disease induced by these regimens. We propose inhibiting ICBT to improve the overall efficacy of anticancer therapies and limit their prometastatic side effects.
Zhen Lu, Angelica Ortiz, Ioannis I. Verginadis, Amy R. Peck, Farima Zahedi, Christina Cho, Pengfei Yu, Rachel M. DeRita, Hongru Zhang, Ryan Kubanoff, Yunguang Sun, Andrew T. Yaspan, Elise Krespan, Daniel P. Beiting, Enrico Radaelli, Sandra W. Ryeom, J. Alan Diehl, Hallgeir Rui, Constantinos Koumenis, Serge Y. Fuchs
Prostate cancer (PC) is driven by androgen receptor (AR) activity, a master regulator of prostate development and homeostasis. Frontline therapies for metastatic PC deprive the AR of the activating ligands testosterone (T) and dihydrotestosterone (DHT) by limiting their biosynthesis or blocking AR binding. Notably, AR signaling is dichotomous, inducing growth at lower activity levels, while suppressing growth at higher levels. Recent clinical studies have exploited this effect by administration of supraphysiological concentrations of T, resulting in clinical responses and improvements in quality of life. However, the use of T as a therapeutic agent in oncology is limited by poor drug-like properties as well as rapid and variable metabolism. Here, we investigated the antitumor effects of selective AR modulators (SARMs), which are small-molecule nonsteroidal AR agonists developed to treat muscle wasting and cachexia. Several orally administered SARMs activated the AR program in PC models. AR cistromes regulated by steroidal androgens and SARMs were superimposable. Coregulatory proteins including HOXB13 and GRHL2 comprised AR complexes assembled by both androgens and SARMs. At bioavailable concentrations, SARMs repressed MYC oncoprotein expression and inhibited the growth of castration-sensitive and castration-resistant PC in vitro and in vivo. These results support further clinical investigation of SARMs for treating advanced PC.
Michael D. Nyquist, Lisa S. Ang, Alexandra Corella, Ilsa M. Coleman, Michael P. Meers, Anthony J. Christiani, Cordell Pierce, Derek H. Janssens, Hannah E. Meade, Arnab Bose, Lauren Brady, Timothy Howard, Navonil De Sarkar, Sander B. Frank, Ruth F. Dumpit, James T. Dalton, Eva Corey, Stephen R. Plymate, Michael C. Haffner, Elahe A. Mostaghel, Peter S. Nelson
Synovial sarcoma is an aggressive malignancy with no effective treatments for patients with metastasis. The synovial sarcoma fusion, SS18-SSX, which recruits the SWI/SNF-BAF chromatin remodeling and polycomb repressive complexes, results in epigenetic activation of FGFR signaling. In genetic FGFR knockout models, culture, and xenograft synovial sarcoma models treated with the FGFR inhibitor BGJ398, we show that FGFR1, FGFR2, and FGFR3 were crucial for tumor growth. Transcriptome analyses of BGJ398-treated cells, histological and expression analyses of mouse and human synovial sarcoma tumors revealed prevalent expression of two ETS factors and FGFR targets, ETV4 and ETV5. We further demonstrate that ETV4 and ETV5 acted as drivers of synovial sarcoma growth, most likely through control of the cell cycle. Upon ETV4 and ETV5 knockdown, we observed a striking upregulation of DUX4 and its transcriptional targets that activate the zygotic genome and drive the atrophy program in facioscapulohumeral dystrophy (FSHD) patients. In addition to demonstrating the importance of inhibiting all three FGFR receptors, the current findings reveal potential nodes of attack for the cancer with the discovery of ETV4 and ETV5 as appropriate biomarkers and molecular targets, and activation of the embryonic DUX4 pathway as a promising approach to block synovial sarcoma tumors.
Joanna DeSalvo, Yuguang Ban, Luyuan Li, Xiaodian Sun, Zhijie Jiang, Darcy A. Kerr, Mahsa Khanlari, Maria Boulina, Mario R. Capecchi, Juha M. Partanen, Lin Chen, Tadashi Kondo, David M. Ornitz, Jonathan C. Trent, Josiane E. Eid