STAT5B is often mutated in hematopoietic malignancies. The most frequent STAT5B mutation, Asp642His (N642H), has been found in over 90 leukemia and lymphoma patients. Here, we used the Vav1 promoter to generate transgenic mouse models that expressed either human STAT5B or STAT5BN642H in the hematopoietic compartment. While STAT5B-expressing mice lacked a hematopoietic phenotype, the STAT5BN642H-expressing mice rapidly developed T cell neoplasms. Neoplasia manifested as transplantable CD8+ lymphoma or leukemia, indicating that the STAT5BN642H mutation drives cancer development. Persistent and enhanced levels of STAT5BN642H tyrosine phosphorylation in transformed CD8+ T cells led to profound changes in gene expression that were accompanied by alterations in DNA methylation at potential histone methyltransferase EZH2-binding sites. Aurora kinase genes were enriched in STAT5BN642H-expressing CD8+ T cells, which were exquisitely sensitive to JAK and Aurora kinase inhibitors. Together, our data suggest that JAK and Aurora kinase inhibitors should be further explored as potential therapeutics for lymphoma and leukemia patients with the STAT5BN642H mutation who respond poorly to conventional chemotherapy.
Ha Thi Thanh Pham, Barbara Maurer, Michaela Prchal-Murphy, Reinhard Grausenburger, Eva Grundschober, Tahereh Javaheri, Harini Nivarthi, Auke Boersma, Thomas Kolbe, Mohamed Elabd, Florian Halbritter, Jan Pencik, Zahra Kazemi, Florian Grebien, Markus Hengstschläger, Lukas Kenner, Stefan Kubicek, Matthias Farlik, Christoph Bock, Peter Valent, Mathias Müller, Thomas Rülicke, Veronika Sexl, Richard Moriggl
Nearly 50% of prostate cancers harbor gene fusions that lead to overexpression of the transcription factor ERG, while a mutually exclusive 10% of prostate cancers harbor recurrent mutations in the gene encoding the E3 ubiquitin ligase SPOP. Recent reports suggest that SPOP acts as a ubiquitin ligase for ERG and propose that ERG stabilization is the oncogenic effector of SPOP mutation. Here, we used human prostate cancer samples and showed that the vast majority of human SPOP-mutant cancers do not express ERG. Comparison of SPOP-mutant and ERG-fusion organoid models showed evidence of divergent, rather than common, transcriptional programs. Furthermore, expression of prostate cancer–associated SPOP mutations in genetically engineered mouse models of SPOP-mutant prostate cancer did not result in the expression of ERG protein in histologically normal prostate glands, high-grade prostatic intraepithelial neoplasia, invasive adenocarcinoma, or prostate organoids. In summary, we found no evidence that ERG is an effector of SPOP mutation in human prostate cancer or mouse models.
Jonathan Shoag, Deli Liu, Mirjam Blattner, Andrea Sboner, Kyung Park, Lesa Deonarine, Brian D. Robinson, Juan Miguel Mosquera, Yu Chen, Mark A. Rubin, Christopher E. Barbieri
During tumor progression, immune system phagocytes continually clear apoptotic cancer cells in a process known as efferocytosis. However, the impact of efferocytosis in metastatic tumor growth is unknown. In this study, we observed that macrophage-driven efferocytosis of prostate cancer cells in vitro induced the expression of proinflammatory cytokines such as CXCL5 by activating Stat3 and NF-κB(p65) signaling. Administration of a dimerizer ligand (AP20187) triggered apoptosis in 2 in vivo syngeneic models of bone tumor growth in which apoptosis-inducible prostate cancer cells were either coimplanted with vertebral bodies, or inoculated in the tibiae of immunocompetent mice. Induction of 2 pulses of apoptosis correlated with increased infiltration of inflammatory cells and accelerated tumor growth in the bone. Apoptosis-induced tumors displayed elevated expression of the proinflammatory cytokine CXCL5. Likewise, CXCL5-deficient mice had reduced tumor progression. Peripheral blood monocytes isolated from patients with bone metastasis of prostate cancer were more efferocytic compared with normal controls, and CXCL5 serum levels were higher in metastatic prostate cancer patients relative to patients with localized prostate cancer or controls. Altogether, these findings suggest that the myeloid phagocytic clearance of apoptotic cancer cells accelerates CXCL5-mediated inflammation and tumor growth in bone, pointing to CXCL5 as a potential target for cancer therapeutics.
Hernan Roca, Jacqueline D. Jones, Marta C. Purica, Savannah Weidner, Amy J. Koh, Robert Kuo, John E. Wilkinson, Yugang Wang, Stephanie Daignault-Newton, Kenneth J. Pienta, Todd M. Morgan, Evan T. Keller, Jacques E. Nör, Lonnie D. Shea, Laurie K. McCauley
Metabolic reprogramming in breast tumors is linked to increases in putative oncogenic metabolites that may contribute to malignant transformation. We previously showed that accumulation of the oncometabolite, 2-hydroxyglutarate (2HG), in breast tumors was associated with MYC signaling, but not with isocitrate dehydrogenase (IDH) mutations, suggesting a distinct mechanism for increased 2HG in breast cancer. Here, we determined that D-2HG is the predominant enantiomer in human breast tumors and show that the D-2HG–producing mitochondrial enzyme, alcohol dehydrogenase, iron-containing protein 1 (ADHFE1), is a breast cancer oncogene that decreases patient survival. We found that MYC upregulates ADHFE1 through changes in iron metabolism while coexpression of both ADHFE1 and MYC strongly enhanced orthotopic tumor growth in MCF7 cells. Moreover, ADHFE1 promoted metabolic reprogramming with increased formation of D-2HG and reactive oxygen, a reductive glutamine metabolism, and modifications of the epigenetic landscape, leading to cellular dedifferentiation, enhanced mesenchymal transition, and phenocopying alterations that occur with high D-2HG levels in cancer cells with IDH mutations. Together, our data support the hypothesis that ADHFE1 and MYC signaling contribute to D-2HG accumulation in breast tumors and show that D-2HG is an oncogenic metabolite and potential driver of disease progression.
Prachi Mishra, Wei Tang, Vasanta Putluri, Tiffany H. Dorsey, Feng Jin, Fang Wang, Donewei Zhu, Lauren Amable, Tao Deng, Shaofei Zhang, J. Keith Killian, Yonghong Wang, Tsion Z. Minas, Harry G. Yfantis, Dong H. Lee, Arun Sreekumar, Michael Bustin, Wei Liu, Nagireddy Putluri, Stefan Ambs
Medulloblastoma, an aggressive cancer of the cerebellum, is among the most common pediatric brain tumors. Approximately one-third of medulloblastomas are associated with misactivation of the Hedgehog (Hh) pathway. GLI family zinc finger 2 (GLI2) coordinates the Hh transcriptional program; however, the GLI2 targets that promote cancer cell proliferation are unknown. Here, we incorporated a Gli2-EGFP allele into 2 different genetic mouse models of Hh-associated medulloblastoma. Hh signaling induced GLI2 binding to the Cdk6 promoter and activated Cdk6 expression, thereby promoting uncontrolled cell proliferation. Genetic or pharmacological inhibition of CDK6 in mice repressed the growth of Hh-associated medulloblastoma and prolonged survival through inhibition of cell proliferation. In human medulloblastoma, misactivation of Hh signaling was associated with high levels of CDK6, pointing to CDK6 as a direct transcriptional target of the Hh pathway. These results suggest that CDK6 antagonists may be a promising therapeutic approach for Hh-associated medulloblastoma in humans.
David R. Raleigh, Pervinder K. Choksi, Alexis Leigh Krup, Wasima Mayer, Nicole Santos, Jeremy F. Reiter
Synovial sarcoma (SS) is an aggressive soft-tissue sarcoma that is often discovered during adolescence and young adulthood. Despite the name, synovial sarcoma does not typically arise from a synoviocyte but instead arises in close proximity to bones. Previous work demonstrated that mice expressing the characteristic SS18-SSX fusion oncogene in myogenic factor 5–expressing (Myf5-expressing) cells develop fully penetrant sarcomagenesis, suggesting skeletal muscle progenitor cell origin. However, Myf5 is not restricted to committed myoblasts in embryos but is also expressed in multipotent mesenchymal progenitors. Here, we demonstrated that human SS and mouse tumors arising from SS18-SSX expression in the embryonic, but not postnatal, Myf5 lineage share an anatomic location that is frequently adjacent to bone. Additionally, we showed that SS can originate from periosteal cells expressing SS18-SSX alone and from preosteoblasts expressing the fusion oncogene accompanied by the added stabilization of β-catenin, which is a common secondary change in SS. Expression and secretion of the osteoclastogenesis inhibitory factor osteoprotegerin enabled early growth of SS18-SSX2–transformed cells, indicating a paracrine link between the bone and synovial sarcomagenesis. These findings explain the skeletal contact frequently observed in human SS and may provide alternate means of enabling SS18-SSX–driven oncogenesis in cells as differentiated as preosteoblasts.
Jared J. Barrott, Benjamin E. Illum, Huifeng Jin, Matthew L. Hedberg, Yanliang Wang, Allie Grossmann, Malay Haldar, Mario R. Capecchi, Kevin B. Jones
p120-Catenin (p120) functions as a tumor suppressor in intestinal cancer, but the mechanism is unclear. Here, using conditional p120 knockout in Apc-sensitized mouse models of intestinal cancer, we have identified p120 as an “obligatory” haploinsufficient tumor suppressor. Whereas monoallelic loss of p120 was associated with a significant increase in tumor multiplicity, loss of both alleles was never observed in tumors from these mice. Moreover, forced ablation of the second allele did not further enhance tumorigenesis, but instead induced synthetic lethality in combination with Apc loss of heterozygosity. In tumor-derived organoid cultures, elimination of both p120 alleles resulted in caspase-3–dependent apoptosis that was blocked by inhibition of Rho kinase (ROCK). With ROCK inhibition, however, p120-ablated organoids exhibited a branching phenotype and a substantial increase in cell proliferation. Access to data from Sleeping Beauty mutagenesis screens afforded an opportunity to directly assess the tumorigenic impact of p120 haploinsufficiency relative to other candidate drivers. Remarkably, p120 ranked third among the 919 drivers identified. Cofactors α-catenin and epithelial cadherin (E-cadherin) were also among the highest scoring candidates, indicating a mechanism at the level of the intact complex that may play an important role at very early stages of of intestinal tumorigenesis while simultaneously restricting outright loss via synthetic lethality.
Sarah P. Short, Jumpei Kondo, Whitney G. Smalley-Freed, Haruna Takeda, Michael R. Dohn, Anne E. Powell, Robert H. Carnahan, Mary K. Washington, Manish Tripathi, D. Michael Payne, Nancy A. Jenkins, Neal G. Copeland, Robert J. Coffey, Albert B. Reynolds
Conventional therapies for breast cancer brain metastases (BCBMs) have been largely ineffective because of chemoresistance and impermeability of the blood-brain barrier. A comprehensive understanding of the underlying mechanism that allows breast cancer cells to infiltrate the brain is necessary to circumvent treatment resistance of BCBMs. Here, we determined that expression of a long noncoding RNA (lncRNA) that we have named lncRNA associated with BCBM (Lnc-BM) is prognostic of the progression of brain metastasis in breast cancer patients. In preclinical murine models, elevated Lnc-BM expression drove BCBM, while depletion of Lnc-BM with nanoparticle-encapsulated siRNAs effectively treated BCBM. Lnc-BM increased JAK2 kinase activity to mediate oncostatin M– and IL-6–triggered STAT3 phosphorylation. In breast cancer cells, Lnc-BM promoted STAT3-dependent expression of ICAM1 and CCL2, which mediated vascular co-option and recruitment of macrophages in the brain, respectively. Recruited macrophages in turn produced oncostatin M and IL-6, thereby further activating the Lnc-BM/JAK2/STAT3 pathway and enhancing BCBM. Collectively, our results show that Lnc-BM and JAK2 promote BCBMs by mediating communication between breast cancer cells and the brain microenvironment. Moreover, these results suggest targeting Lnc-BM as a potential strategy for fighting this difficult disease.
Shouyu Wang, Ke Liang, Qingsong Hu, Ping Li, Jian Song, Yuedong Yang, Jun Yao, Lingegowda Selanere Mangala, Chunlai Li, Wenhao Yang, Peter K. Park, David H. Hawke, Jianwei Zhou, Yan Zhou, Weiya Xia, Mien-Chie Hung, Jeffrey R. Marks, Gary E. Gallick, Gabriel Lopez-Berestein, Elsa R. Flores, Anil K. Sood, Suyun Huang, Dihua Yu, Liuqing Yang, Chunru Lin
Transcriptional repression of ubiquitin B (UBB) is a cancer-subtype-specific alteration that occurs in a substantial population of patients with cancers of the female reproductive tract. UBB is 1 of 2 genes encoding for ubiquitin as a polyprotein consisting of multiple copies of ubiquitin monomers. Silencing of UBB reduces cellular UBB levels and results in an exquisite dependence on ubiquitin C (UBC), the second polyubiquitin gene. UBB is repressed in approximately 30% of high-grade serous ovarian cancer (HGSOC) patients and is a recurrent lesion in uterine carcinosarcoma and endometrial carcinoma. We identified ovarian tumor cell lines that retain UBB in a repressed state, used these cell lines to establish orthotopic ovarian tumors, and found that inducible expression of a UBC-targeting shRNA led to tumor regression, and substantial long-term survival benefit. Thus, we describe a recurrent cancer-specific lesion at the level of ubiquitin production. Moreover, these observations reveal the prognostic value of UBB repression and establish UBC as a promising therapeutic target for ovarian cancer patients with recurrent UBB silencing.
Alexia T. Kedves, Scott Gleim, Xiaoyou Liang, Dennis M. Bonal, Frederic Sigoillot, Fred Harbinski, Sneha Sanghavi, Christina Benander, Elizabeth George, Prafulla C. Gokhale, Quang-De Nguyen, Paul T. Kirschmeier, Robert J. Distel, Jeremy Jenkins, Michael S. Goldberg, William C. Forrester
NK cells, lymphocytes of the innate immune system, are important for defense against infectious pathogens and cancer. Classically, the CD56dim NK cell subset is thought to mediate antitumor responses, whereas the CD56bright subset is involved in immunomodulation. Here, we challenge this paradigm by demonstrating that brief priming with IL-15 markedly enhanced the antitumor response of CD56bright NK cells. Priming improved multiple CD56bright cell functions: degranulation, cytotoxicity, and cytokine production. Primed CD56bright cells from leukemia patients demonstrated enhanced responses to autologous blasts in vitro, and primed CD56bright cells controlled leukemia cells in vivo in a murine xenograft model. Primed CD56bright cells from multiple myeloma (MM) patients displayed superior responses to autologous myeloma targets, and furthermore, CD56bright NK cells from MM patients primed with the IL-15 receptor agonist ALT-803 in vivo displayed enhanced ex vivo functional responses to MM targets. Effector mechanisms contributing to IL-15–based priming included improved cytotoxic protein expression, target cell conjugation, and LFA-1–, CD2-, and NKG2D-dependent activation of NK cells. Finally, IL-15 robustly stimulated the PI3K/Akt/mTOR and MEK/ERK pathways in CD56bright compared with CD56dim NK cells, and blockade of these pathways attenuated antitumor responses. These findings identify CD56bright NK cells as potent antitumor effectors that warrant further investigation as a cancer immunotherapy.
Julia A. Wagner, Maximillian Rosario, Rizwan Romee, Melissa M. Berrien-Elliott, Stephanie E. Schneider, Jeffrey W. Leong, Ryan P. Sullivan, Brea A. Jewell, Michelle Becker-Hapak, Timothy Schappe, Sara Abdel-Latif, Aaron R. Ireland, Devika Jaishankar, Justin A. King, Ravi Vij, Dennis Clement, Jodie Goodridge, Karl-Johan Malmberg, Hing C. Wong, Todd A. Fehniger