Oncology
Abstract
Inducible nitric oxide synthase (NOS2) is involved in wound healing, angiogenesis, and carcinogenesis. NOS2 upregulation and increased nitric oxide (NO) production affect the redox state of cells and can induce protein, lipid, and DNA modifications. To investigate whether NOS2 levels influence survival of breast cancer patients, we examined NOS2 expression and its association with tumor markers and survival in 248 breast tumors. In multivariable survival analysis, increased NOS2 predicted inferior survival in women with estrogen receptor α–negative (ER-negative) tumors. Microdissected tumor epithelium from ER-negative tumors with high NOS2 had increased IL-8 and a gene expression signature characteristic of basal-like breast cancer with poor prognosis. In cell culture, NO only induced selected signature genes in ER-negative breast cancer cells. ER transgene expression in ER-negative cells inhibited NO-induced upregulation of the stem cell marker CD44 and other proteins encoded by signature genes, but not of IL-8. Exposure to NO also enhanced cell motility and invasion of ER-negative cells. Last, pathway analysis linked the tumor NOS2 gene signature to c-Myc activation. Thus, NOS2 is associated with a basal-like transcription pattern and poor survival of ER-negative patients.
Authors
Sharon A. Glynn, Brenda J. Boersma, Tiffany H. Dorsey, Ming Yi, Harris G. Yfantis, Lisa A. Ridnour, Damali N. Martin, Christopher H. Switzer, Robert S. Hudson, David A. Wink, Dong H. Lee, Robert M. Stephens, Stefan Ambs
Abstract
Cyclin E is often overexpressed in cancer tissue, leading to genetic instability and aneuploidy. Cullin 3 (Cul3) is a component of the BTB-Cul3-Rbx1 (BCR) ubiquitin ligase that is involved in the turnover of cyclin E. Here we show that liver-specific ablation of Cul3 in mice results in the persistence and massive expansion of hepatic progenitor cells. Upon induction of differentiation, Cul3-deficient progenitor cells underwent substantial DNA damage in vivo and in vitro, thereby triggering the activation of a cellular senescence response that selectively blocked the expansion of the differentiated offspring. Positive selection of undifferentiated progenitor cells required the expression of the tumor suppressor protein p53. Simultaneous loss of Cul3 and p53 in hepatic progenitors turned these cells into highly malignant tumor-initiating cells that formed largely undifferentiated tumors in nude mice. In addition, loss of Cul3 and p53 led to the formation of primary hepatocellular carcinomas. Importantly, loss of Cul3 expression was also detected in a large series of human liver cancers and correlated directly with tumor de-differentiation. The expression of Cul3 during hepatic differentiation therefore safeguards against the formation of progenitor cells that carry a great potential for transformation into tumor-initiating cells.
Authors
Uta Kossatz, Kai Breuhahn, Benita Wolf, Matthias Hardtke-Wolenski, Ludwig Wilkens, Doris Steinemann, Stephan Singer, Felicitas Brass, Stefan Kubicka, Brigitte Schlegelberger, Peter Schirmacher, Michael P. Manns, Jeffrey D. Singer, Nisar P. Malek
Abstract
The apoptosis inhibitor protein survivin is overexpressed in many tumors, making it a candidate target molecule for various forms of immunotherapy. To explore survivin as a target antigen for adoptive T cell therapy using lymphocytes expressing survivin-specific transgenic T cell receptors (Tg-TCRs), we isolated HLA-A2–allorestricted survivin-specific T cells with high functional avidity. Lymphocytes expressing Tg-TCRs were derived from these T cells and specifically recognized HLA-A2+ survivin+ tumor cells. Surprisingly, HLA-A2+ but not HLA-A2– lymphocytes expressing Tg-TCRs underwent extensive apoptosis over time. This demise was caused by HLA-A2–restricted fratricide that occurred due to survivin expression in lymphocytes, which created ligands for Tg-TCR recognition. Therefore, survivin-specific TCR gene therapy would be limited to application in HLA-A2–mismatched stem cell transplantation. We also noted that lymphocytes that expressed survivin-specific Tg-TCRs killed T cell clones of various specificities derived from HLA-A2+ but not HLA-A2– donors. These results raise a general question regarding the development of cancer vaccines that target proteins that are also expressed in activated lymphocytes, since induction of high-avidity T cells that expand in lymph nodes following vaccination or later accumulate at tumor sites might limit themselves by self-MHC–restricted fratricide while at the same time inadvertently eliminating neighboring T cells of other specificities.
Authors
Matthias Leisegang, Susanne Wilde, Stefani Spranger, Slavoljub Milosevic, Bernhard Frankenberger, Wolfgang Uckert, Dolores J. Schendel
The cytomegalovirus-encoded chemokine receptor US28 promotes intestinal neoplasia in transgenic mice
Abstract
US28 is a constitutively active chemokine receptor encoded by CMV (also referred to as human herpesvirus 5), a highly prevalent human virus that infects a broad spectrum of cells, including intestinal epithelial cells (IECs). To study the role of US28 in vivo, we created transgenic mice (VS28 mice) in which US28 expression was targeted to IECs. Expression of US28 was detected in all IECs of the small and large intestine, including in cells expressing leucine rich repeat containing GPCR5 (Lgr5), a marker gene of intestinal epithelial stem cells. US28 expression in IECs inhibited glycogen synthase 3β (GSK-3β) function, promoted accumulation of β-catenin protein, and increased expression of Wnt target genes involved in the control of the cell proliferation. VS28 mice showed a hyperplastic intestinal epithelium and, strikingly, developed adenomas and adenocarcinomas by 40 weeks of age. When exposed to an inflammation-driven tumor model (azoxymethane/dextran sodium sulfate), VS28 mice developed a significantly higher tumor burden than control littermates. Transgenic coexpression of the US28 ligand CCL2 (an inflammatory chemokine) increased IEC proliferation as well as tumor burden, suggesting that the oncogenic activity of US28 can be modulated by inflammatory factors. Together, these results indicate that expression of US28 promotes development of intestinal dysplasia and cancer in transgenic mice and suggest that CMV infection may facilitate development of intestinal neoplasia in humans.
Authors
Gerold Bongers, David Maussang, Luciana R. Muniz, Vanessa M. Noriega, Alberto Fraile-Ramos, Nick Barker, Federica Marchesi, Nanthakumar Thirunarayanan, Henry F. Vischer, Lihui Qin, Lloyd Mayer, Noam Harpaz, Rob Leurs, Glaucia C. Furtado, Hans Clevers, Domenico Tortorella, Martine J. Smit, Sergio A. Lira
Abstract
Authors
Arnulfo Mendoza, Sung-Hyeok Hong, Tanasa Osborne, Mohammed A. Khan, Kirk Campbell, Joseph Briggs, Ananth Eleswarapu, Lauren Buquo, Ling Ren, Stephen M. Hewitt, EL Habib Dakir, Susan Garfield, Renard Walker, Glenn Merlino, Jeffrey E. Green, Kent W. Hunter, Lalage M. Wakefield, Chand Khanna
Abstract
TGF-β signaling can promote tumor formation and development or suppress it, depending on the cellular context and tumor stage. A potential target of this dual effect of TGF-β is HGF, as TGF-β can inhibit or promote its expression, although the mechanisms underlying this are largely unknown. In the present study, we found that mice with keratinocyte-specific deletion of the TGF-β signaling mediator Smad2 (referred to herein as K5.Smad2–/– mice), which have increased susceptibility to squamous cell carcinomas (SCCs), exhibited angiogenesis associated with epithelial overexpression of HGF and endothelial activation of the HGF receptor c-Met. Application of a c-Met inhibitor abrogated angiogenesis, suggesting that HGF overexpression plays a major role in angiogenesis associated with epithelial Smad2 loss. On the Hgf promoter, Smad2 was mainly associated with transcriptional corepressors, whereas Smad4 was mainly associated with the transcriptional coactivator CREB-binding protein (CBP/p300). Smad2 loss caused increased binding of Smad4 and CBP/p300 to the Hgf promoter. Consistent with this, knocking down Smad2 in human keratinocytes caused increased levels of HGF, which were abrogated by concomitant knockdown of Smad3 and Smad4. Importantly, the incidence of HGF-positive human SCC was high in cases with Smad2 loss and lower when Smad4 was also lost. We therefore conclude that Smad2 loss causes HGF upregulation via loss of Smad2-mediated transcriptional repression and enhanced Smad3/4-mediated transactivation. Since Smad2 is often downregulated in human SCCs, our data suggest a therapeutic strategy of blocking HGF/c-Met activation for Smad2-deficient SCCs.
Authors
Kristina E. Hoot, Masako Oka, Gangwen Han, Erwin Bottinger, Qinghong Zhang, Xiao-Jing Wang
Abstract
Accumulating evidence points to inflammation as a promoter of carcinogenesis. MyD88 is an adaptor molecule in TLR and IL-1R signaling that was recently implicated in tumorigenesis through proinflammatory mechanisms. Here we have shown that MyD88 is also required in a cell-autonomous fashion for RAS-mediated carcinogenesis in mice in vivo and for MAPK activation and transformation in vitro. Mechanistically, MyD88 bound to the key MAPK, Erk, and prevented its inactivation by its phosphatase, MKP3, thereby amplifying the activation of the canonical RAS pathway. The relevance of this mechanism to human neoplasia was suggested by the finding that MyD88 was overexpressed and interacted with activated Erk in primary human cancer tissues. Collectively, these results show that in addition to its role in inflammation, MyD88 plays what we believe to be a crucial direct role in RAS signaling, cell-cycle control, and cell transformation.
Authors
Isabelle Coste, Katy Le Corf, Alain Kfoury, Isabelle Hmitou, Sabine Druillennec, Pierre Hainaut, Alain Eychene, Serge Lebecque, Toufic Renno
Abstract
Platinum-based chemotherapies such as cisplatin are used as first-line treatment for many cancers. Although there is often a high initial responsiveness, the majority of patients eventually relapse with platinum-resistant disease. For example, a subset of testicular cancer patients still die even though testicular cancer is considered a paradigm of cisplatin-sensitive solid tumors, but the mechanisms of chemoresistance remain elusive. Here, we have shown that one key determinant of cisplatin-resistance in testicular embryonal carcinoma (EC) is high cytoplasmic expression of the cyclin-dependent kinase (CDK) inhibitor p21. The EC component of the majority of refractory testicular cancer patients exhibited high cytoplasmic p21 expression, which protected EC cell lines against cisplatin-induced apoptosis via CDK2 inhibition. Localization of p21 in the cytoplasm was critical for cisplatin resistance, since relocalization of p21 to the nucleus by Akt inhibition sensitized EC cell lines to cisplatin. We also demonstrated in EC cell lines and human tumor tissue that high cytoplasmic p21 expression and cisplatin resistance of EC were inversely associated with the expression of Oct4 and miR-106b seed family members. Thus, targeting cytoplasmic p21, including by modulation of the Oct4/miR-106b/p21 pathway, may offer new strategies for the treatment of chemoresistant testicular and other types of cancer.
Authors
Roelof Koster, Alessandra di Pietro, Hetty Timmer-Bosscha, Johan H. Gibcus, Anke van den Berg, Albert J. Suurmeijer, Rainer Bischoff, Jourik A. Gietema, Steven de Jong
Abstract
Cancer stem cells (CSCs) are generally dormant or slowly cycling tumor cells that have the ability to reconstitute tumors. They are thought to be involved in tumor resistance to chemo/radiation therapy and tumor relapse and progression. However, neither their existence nor their identity within many cancers has been well defined. Here, we have demonstrated that CD13 is a marker for semiquiescent CSCs in human liver cancer cell lines and clinical samples and that targeting these cells might provide a way to treat this disease. CD13+ cells predominated in the G0 phase of the cell cycle and typically formed cellular clusters in cancer foci. Following treatment, these cells survived and were enriched along the fibrous capsule where liver cancers usually relapse. Mechanistically, CD13 reduced ROS-induced DNA damage after genotoxic chemo/radiation stress and protected cells from apoptosis. In mouse xenograft models, combination of a CD13 inhibitor and the genotoxic chemotherapeutic fluorouracil (5-FU) drastically reduced tumor volume compared with either agent alone. 5-FU inhibited CD90+ proliferating CSCs, some of which produce CD13+ semiquiescent CSCs, while CD13 inhibition suppressed the self-renewing and tumor-initiating ability of dormant CSCs. Therefore, combining a CD13 inhibitor with a ROS-inducing chemo/radiation therapy may improve the treatment of liver cancer.
Authors
Naotsugu Haraguchi, Hideshi Ishii, Koshi Mimori, Fumiaki Tanaka, Masahisa Ohkuma, Ho Min Kim, Hirofumi Akita, Daisuke Takiuchi, Hisanori Hatano, Hiroaki Nagano, Graham F. Barnard, Yuichiro Doki, Masaki Mori
Abstract
Some cancers have been stratified into subclasses based on their unique involvement of specific signaling pathways. The mapping of human cancer genomes is revealing a vast number of somatic alterations; however, the identification of clinically relevant molecular tumor subclasses and their respective driver genes presents challenges. This information is key to developing more targeted and personalized cancer therapies. Here, we generate a new mouse model of genomically unstable osteosarcoma (OSA) that phenocopies the human disease. Integrative oncogenomics pinpointed cAMP-dependent protein kinase type I, α regulatory subunit (Prkar1a) gene deletions at 11qE1 as a recurrent genetic trait for a molecularly distinct subclass of mouse OSA featuring RANKL overexpression. Using mouse genetics, we established that Prkar1a is a bone tumor suppressor gene capable of directing subclass development and driving RANKL overexpression during OSA tumorigenesis. Finally, we uncovered evidence for a PRKAR1A-low subset of human OSA with distinct clinical behavior. Thus, tumor subclasses develop in mice and can potentially provide information toward the molecular stratification of human cancers.
Authors
Sam D. Molyneux, Marco A. Di Grappa, Alexander G. Beristain, Trevor D. McKee, Daniel H. Wai, Jana Paderova, Meenakshi Kashyap, Pingzhao Hu, Tamara Maiuri, Swami R. Narala, Vuk Stambolic, Jeremy Squire, Josef Penninger, Otto Sanchez, Timothy J. Triche, Geoffrey A. Wood, Lawrence S. Kirschner, Rama Khokha
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)