Oncology
Abstract
A homozygous truncating frameshift mutation in CEP57 (CEP57T/T) has been identified in a subset of mosaic-variegated aneuploidy (MVA) patients; however, the physiological roles of the centrosome-associated protein CEP57 that contribute to disease are unknown. To investigate these, we have generated a mouse model mimicking this disease mutation. Cep57T/T mice died within 24 hours after birth with short, curly tails and severely impaired vertebral ossification. Osteoblasts in lumbosacral vertebrae of Cep57T/T mice were deficient for Fgf2, a Cep57 binding partner implicated in diverse biological processes, including bone formation. Furthermore, a broad spectrum of tissues of Cep57T/T mice had severe aneuploidy at birth, consistent with the MVA patient phenotype. Cep57T/T mouse embryonic fibroblasts and patient-derived skin fibroblasts failed to undergo centrosome maturation in G2 phase, causing premature centriole disjunction, centrosome amplification, aberrant spindle formation, and high rates of chromosome missegregation. Mice heterozygous for the truncating frameshift mutation or a Cep57-null allele were overtly indistinguishable from WT mice despite reduced Cep57 protein levels, yet prone to aneuploidization and cancer, with tumors lacking evidence for loss of heterozygosity. This study identifies Cep57 as a haploinsufficient tumor suppressor with biologically diverse roles in centrosome maturation and Fgf2-mediated bone formation.
Authors
Khaled Aziz, Cynthia J. Sieben, Karthik B. Jeganathan, Masakazu Hamada, Brian A. Davies, Raul O. Fierro Velasco, Nazneen Rahman, David J. Katzmann, Jan M. van Deursen
Abstract
The MALT1 paracaspase plays an essential role in Activated B-cell like Diffuse Large B cell Lymphoma (ABC DLBCL) downstream of B cell and Toll-like receptor pathway genes mutated in these tumors. Although MALT1 is considered to be a compelling therapeutic target, development of tractable and specific MALT1 protease inhibitors has thus far been elusive. Herein, we developed a target engagement assay that provides a quantitative readout for specific MALT1 inhibitory effects in living cells. This enabled a structure-guided medicinal chemistry effort culminating in the discovery of pharmacologically tractable irreversible substrate-mimetic compounds that bind the MALT1 active site. We confirmed MALT1 targeting with compound #3 is effective at suppressing ABC DLBCL cells in vitro and in vivo. We show that reduction in serum IL10 levels exquisitely correlates with drug PK and degree of MALT1 inhibition in vitro and in vivo and could constitute a useful pharmacodynamic biomarker to evaluate these compounds in clinical trials. Compound #3 revealed insights into the biology of MALT1 in ABC DLBCL, such as driving JAK-STAT signaling and suppressing type I interferon (IFN) response and MHC class II expression, suggesting that MALT1 inhibition could prime lymphomas for immune recognition by cytotoxic immune cells.
Authors
Lorena Fontán, Qi Qiao, John M. Hatcher, Gabriella Casalena, Ilkay Us, Matt Teater, Matthew Durant, Guangyan Du, Min Xia, Natalia Bilchuk, Spandan Chennamadhavuni, Giuseppe Palladino, Giorgio Inghirami, Ulrike Philippar, Hao Wu, David A. Scott, Nathanael S. Gray, Ari Melnick
Abstract
Nucleophosmin (NPM1) is amongst the most frequently mutated genes in acute myeloid leukemia (AML). It is not known, however, how the resulting oncoprotein mutant-NPM1 is leukemogenic. To reveal the cellular machinery in which NPM1 participates in myeloid cells, we analyzed the endogenous NPM1 protein-interactome by mass-spectrometry, and discovered abundant amounts of the master transcription factor driver of monocyte lineage-differentiation PU.1 (SPI1). Mutant-NPM1, which aberrantly accumulates in cytoplasm, dislocated PU.1 into cytoplasm with it. CEBPA and RUNX1, the master transcription factors that collaborate with PU.1 to activate granulo-monocytic lineage-fates, remained nuclear, but without PU.1, their coregulator interactions were toggled from coactivators to corepressors, repressing instead of activating greater than 500 granulocyte and monocyte terminal-differentiation genes. An inhibitor of nuclear export, selinexor, by locking mutant-NPM1/PU.1 in the nucleus, activated terminal monocytic fates. Direct depletion of the corepressor DNA methyltransferase 1 (DNMT1) from the CEBPA/RUNX1 protein interactome using the clinical drug decitabine activated terminal granulocytic fates. Together, these non-cytotoxic treatments extended survival by greater than 160 days versus vehicle in a patient-derived xenotransplant model of NPM1/FLT3-mutated AML. In sum, mutant-NPM1 represses monocyte and granulocyte terminal-differentiation by disrupting PU.1/CEBPA/RUNX1 collaboration, a transforming action that can be reversed by pharmacodynamically-directed dosing of clinical small molecules.
Authors
Xiaorong Gu, Quteba Ebrahem, Reda Z. Mahfouz, Metis Hasipek, Francis Enane, Tomas Radivoyevitch, Nicolas Rapin, Bartlomiej Przychodzen, Zhenbo Hu, Ramesh Balusu, Claudiu V. Cotta, David Wald, Christian Argueta, Yosef Landesman, Maria Paola Martelli, Brunangelo Falini, Hetty Carraway, Bo T. Porse, Jaroslaw P. Maciejewski, Babal K. Jha, Yogen Saunthararajah
Abstract
Chromatin remodeler Brahma related gene 1 (BRG1) is silenced in approximately 10% of human pancreatic ductal adenocarcinomas (PDAs). We previously showed that BRG1 inhibits the formation of intraductal pancreatic mucinous neoplasm (IPMN) and that IPMN-derived PDA originated from ductal cells. However, the role of BRG1 in pancreatic intraepithelial neoplasia–derived (PanIN-derived) PDA that originated from acinar cells remains elusive. Here, we found that exclusive elimination of Brg1 in acinar cells of Ptf1a-CreER; KrasG12D; Brg1fl/fl mice impaired the formation of acinar-to-ductal metaplasia (ADM) and PanIN independently of p53 mutation, while PDA formation was inhibited in the presence of p53 mutation. BRG1 bound to regions of the Sox9 promoter to regulate its expression and was critical for recruitment of upstream regulators, including PDX1, to the Sox9 promoter and enhancer in acinar cells. SOX9 expression was downregulated in BRG1-depleted ADMs/PanINs. Notably, Sox9 overexpression canceled this PanIN-attenuated phenotype in KBC mice. Furthermore, Brg1 deletion in established PanIN by using a dual recombinase system resulted in regression of the lesions in mice. Finally, BRG1 expression correlated with SOX9 expression in human PDAs. In summary, BRG1 is critical for PanIN initiation and progression through positive regulation of SOX9. Thus, the BRG1/SOX9 axis is a potential target for PanIN-derived PDA.
Authors
Motoyuki Tsuda, Akihisa Fukuda, Nilotpal Roy, Yukiko Hiramatsu, Laura Leonhardt, Nobuyuki Kakiuchi, Kaja Hoyer, Satoshi Ogawa, Norihiro Goto, Kozo Ikuta, Yoshito Kimura, Yoshihide Matsumoto, Yutaka Takada, Takuto Yoshioka, Takahisa Maruno, Yuichi Yamaga, Grace E. Kim, Haruhiko Akiyama, Seishi Ogawa, Christopher V. Wright, Dieter Saur, Kyoichi Takaori, Shinji Uemoto, Matthias Hebrok, Tsutomu Chiba, Hiroshi Seno
Abstract
Anaplastic thyroid carcinomas (ATC) have a high prevalence of BRAF and TP53 mutations. A trial of vemurafenib in non-melanoma BRAFV600E-mutant cancers showed significant, although short-lived, responses in ATCs, indicating that these virulent tumors remain addicted to BRAF despite their high mutation burden. To explore the mechanisms mediating acquired resistance to BRAF blockade we generated mice with thyroid-specific deletion of p53 and dox-dependent expression of BRAFV600E, 50% of which developed ATCs after dox treatment. Upon dox withdrawal there was complete regression in all mice, although recurrences were later detected in 85% of animals. The relapsed tumors had elevated MAPK transcriptional output, and retained responses to the MEK/RAF inhibitor CH5126766 in vivo and in vitro. Whole exome sequencing identified recurrent focal amplifications of chromosome 6, with a minimal region of overlap that included Met. Met-amplified recurrences overexpressed the receptor as well as its ligand Hgf. Growth, signaling and viability of Met-amplified tumor cells were suppressed in vitro and in vivo by the Met kinase inhibitors PF-04217903 and crizotinib, whereas primary ATCs and Met-diploid relapses were resistant. Hence, recurrences are the rule after BRAF suppression in murine ATCs, most commonly due to activation of HGF/MET signaling, which generates exquisite dependency to MET kinase inhibitors.
Authors
Jeffrey A. Knauf, Kathleen A. Luckett, Kuen-Yuan Chen, Francesca Voza, Nicholas D. Socci, Ronald Ghossein, James A. Fagin
Abstract
DNA damaging chemotherapy and radiation therapy are integrated into the treatment paradigm of the majority of cancer patients. Recently, immunotherapy that targets the immunosuppressive interaction between Programmed Death 1 (PD-1) and its ligand PD-L1 has been approved for malignancies including non-small lung cancer (NSCLC), melanoma, and head and neck squamous cell carcinoma (HNSCC). ATR is a DNA damage signaling kinase activated at damaged replication forks and ATR kinase inhibitors potentiate the cytotoxicity of DNA damaging chemotherapies. We show here that the ATR kinase inhibitor AZD6738 combines with conformal radiation therapy to attenuate radiation-induced CD8+ T cell exhaustion and potentiate CD8+ T cell activity in mouse models of Kras-mutant cancer. Mechanistically, AZD6738 blocks radiation-induced PD-L1 upregulation on tumor cells and dramatically decreases the number of tumor-infiltrating T regulatory (Treg) cells. Remarkably, AZD6738 combines with conformal radiation therapy to generate immunologic memory in complete responder mice. Our work raises the exciting possibility that a single pharmacologic agent may enhance the cytotoxic effects of radiation while concurrently potentiating radiation-induced antitumor immune responses.
Authors
Frank P. Vendetti, Pooja Karukonda, David A. Clump, Troy Teo, Ronald Lalonde, Katriana Nugent, Matthew Ballew, Brian F. Kiesel, Jan H. Beumer, Saumendra N. Sarkar, Thomas P. Conrads, Mark J. O'Connor, Robert L. Ferris, Phuoc T. Tran, Greg M. Delgoffe, Christopher J. Bakkenist
Abstract
Cancer cell dependence on activated oncogenes is targeted therapeutically, but acquired resistance is virtually unavoidable. Here we show that the treatment of addicted melanoma cells with BRAF-inhibitors, and of breast cancer cells with HER2-targeted drugs, led to an adaptive rise in Neuropilin-1 (NRP1) expression, which is crucial for the onset of acquired resistance to therapy. Moreover, NRP1 levels dictated the efficacy of MET oncogene-inhibitors in addicted stomach and lung carcinoma cells. Mechanistically, NRP1 induced a JNK-dependent signaling cascade leading to the upregulation of alternative effector kinases, EGFR or IGF1R, which in turn sustained cancer cell growth and mediated acquired resistance to BRAF, HER2, or MET inhibitors. Notably, the combination with NRP1-interfering molecules improved the efficacy of oncogene-targeted drugs, and prevented, or even reversed, the onset of resistance in cancer cells and tumor models. Our study provides the rationale for targeting the NRP1-dependent upregulation of tyrosine kinases, responsible for loss of responsiveness to oncogene-targeted therapies.
Authors
Sabrina Rizzolio, Gabriella Cagnoni, Chiara Battistini, Stefano Bonelli, Claudio Isella, Jo A. Van Ginderachter, René Bernards, Federica Di Nicolantonio, Silvia Giordano, Luca Tamagnone
Abstract
Dormant or slow-cycling tumour cells can form a residual chemoresistant reservoir responsible for relapse in patients, years after curative surgery and adjuvant therapy. We have adapted the pulse-chase expression of H2BeGFP for labelling and isolating slow-cycling cancer cells (SCCC). SCCC showed cancer-initiation potential and enhanced chemoresistance. Cells at this slow-cycling status presented a distinctive non-genetic and cell-autonomous gene expression profile shared across different tumour types. We identified TET2 epigenetic enzyme as key factor controlling SCCC numbers, survival and tumour recurrence. 5-Hydroxymethylcytosine (5hmC), generated by TET2 enzymatic activity, labelled SCCC genome in carcinomas and was a predictive biomarker of relapse and survival in cancer patients. We have shown the enhanced chemoresistance of SCCC, revealed 5hmC as a biomarker for their clinical identification, and TET2 as a potential drug-target for SCCC elimination that could extend patients’ survival.
Authors
Isabel Puig, Stephan P. Tenbaum, Irene Chicote, Oriol Arqués, Jordi Martínez-Quintanilla, Estefania Cuesta-Borrás, Lorena Ramírez, Pilar Gonzalo, Atenea Soto, Susana Aguilar, Cristina Eguizabal, Ginevra Caratù, Aleix Prat, Guillem Argilés, Stefania Landolfi, Oriol Casanovas, Violeta Serra, Alberto Villanueva, Alicia G. Arroyo, Luigi Terracciano, Paolo Nuciforo, Joan Seoane, Juan A. Recio, Ana Vivancos, Rodrigo Dienstmann, Josep Tabernero, Héctor G. Palmer
Abstract
High-risk neuroblastoma is a devastating malignancy with very limited therapeutic options. Here, we identify withaferin A (WA) as a natural ferroptosis-inducing agent in neuroblastoma, which acts through a novel double-edged mechanism. WA dose-dependently either activates the nuclear factor–like 2 pathway through targeting of Kelch-like ECH-associated protein 1 (noncanonical ferroptosis induction) or inactivates glutathione peroxidase 4 (canonical ferroptosis induction). Noncanonical ferroptosis induction is characterized by an increase in intracellular labile Fe(II) upon excessive activation of heme oxygenase-1, which is sufficient to induce ferroptosis. This double-edged mechanism might explain the superior efficacy of WA as compared with etoposide or cisplatin in killing a heterogeneous panel of high-risk neuroblastoma cells, and in suppressing the growth and relapse rate of neuroblastoma xenografts. Nano-targeting of WA allows systemic application and suppressed tumor growth due to an enhanced accumulation at the tumor site. Collectively, our data propose a novel therapeutic strategy to efficiently kill cancer cells by ferroptosis.
Authors
Behrouz Hassannia, Bartosz Wiernicki, Irina Ingold, Feng Qu, Simon Van Herck, Yulia Y. Tyurina, Hülya Bayır, Behnaz A. Abhari, Jose Pedro Friedmann Angeli, Sze Men Choi, Eline Meul, Karen Heyninck, Ken Declerck, Chandra Sekhar Chirumamilla, Maija Lahtela-Kakkonen, Guy Van Camp, Dmitri V. Krysko, Paul G. Ekert, Simone Fulda, Bruno G. De Geest, Marcus Conrad, Valerian E. Kagan, Wim Vanden Berghe, Peter Vandenabeele, Tom Vanden Berghe
Abstract
BACKGROUND. A common germline variant in HSD3B1(1245A>C) encodes for a hyperactive 3β-hydroxysteroid dehydrogenase 1 (3βHSD1) missense that increases metabolic flux from extragonadal precursor steroids to DHT synthesis in prostate cancer. Enabling of extragonadal DHT synthesis by HSD3B1(1245C) predicts for more rapid clinical resistance to castration and sensitivity to extragonadal androgen synthesis inhibition. HSD3B1(1245C) thus appears to define a subgroup of patients who benefit from blocking extragonadal androgens. However, abiraterone, which is administered to block extragonadal androgens, is a steroidal drug that is metabolized by 3βHSD1 to multiple steroidal metabolites, including 3-keto-5α-abiraterone, which stimulates the androgen receptor. Our objective was to determine if HSD3B1(1245C) inheritance is associated with increased 3-keto-5α-abiraterone synthesis in patients. METHODS. First, we characterized the pharmacokinetics of 7 steroidal abiraterone metabolites in 15 healthy volunteers. Second, we determined the association between serum 3-keto-5α-abiraterone levels and HSD3B1 genotype in 30 patients treated with abiraterone acetate (AA) after correcting for the determined pharmacokinetics. RESULTS. Patients who inherit 0, 1, and 2 copies of HSD3B1(1245C) have a stepwise increase in normalized 3-keto-5α-abiraterone (0.04 ng/ml, 2.60 ng/ml, and 2.70 ng/ml, respectively; P = 0.002). CONCLUSION. Increased generation of 3-keto-5α-abiraterone in patients with HSD3B1(1245C) might partially negate abiraterone benefits in these patients who are otherwise more likely to benefit from CYP17A1 inhibition. FUNDING. Prostate Cancer Foundation Challenge Award, National Cancer Institute.
Authors
Mohammad Alyamani, Hamid Emamekhoo, Sunho Park, Jennifer Taylor, Nima Almassi, Sunil Upadhyay, Allison Tyler, Michael P. Berk, Bo Hu, Tae Hyun Hwang, William Douglas Figg, Cody J. Peer, Caly Chien, Vadim S. Koshkin, Prateek Mendiratta, Petros Grivas, Brian Rini, Jorge Garcia, Richard J. Auchus, Nima Sharifi
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)