Colitis-associated colorectal cancer (CAC) is a severe complication of inflammatory bowel disease (IBD). HIF-prolyl hydroxylases (PHD1, PHD2, and PHD3) control cellular adaptation to hypoxia and are considered promising therapeutic targets in IBD. However, their relevance in the pathogenesis of CAC remains elusive. We induced CAC in Phd1–/–, Phd2+/–, Phd3–/–, and WT mice with azoxymethane (AOM) and dextran sodium sulfate (DSS). Phd1–/– mice were protected against chronic colitis and displayed diminished CAC growth compared with WT mice. In Phd3–/– mice, colitis activity and CAC growth remained unaltered. In Phd2+/– mice, colitis activity was unaffected, but CAC growth was aggravated. Mechanistically, Phd2 deficiency (i) increased the number of tumor-associated macrophages in AOM/DSS-induced tumors, (ii) promoted the expression of EGFR ligand epiregulin in macrophages, and (iii) augmented the signal transducer and activator of transcription 3 and extracellular signal–regulated kinase 1/2 signaling, which at least in part contributed to aggravated tumor cell proliferation in colitis-associated tumors. Consistently, Phd2 deficiency in hematopoietic (Vav:Cre-Phd2fl/fl) but not in intestinal epithelial cells (Villin:Cre-Phd2fl/fl) increased CAC growth. In conclusion, the 3 different PHD isoenzymes have distinct and nonredundant effects, promoting (PHD1), diminishing (PHD2), or neutral (PHD3), on CAC growth.
Kilian B. Kennel, Julius Burmeister, Praveen Radhakrishnan, Nathalia A. Giese, Thomas Giese, Martin Salfenmoser, Jasper M. Gebhardt, Moritz J. Strowitzki, Cormac T. Taylor, Ben Wielockx, Martin Schneider, Jonathan M. Harnoss
BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) has a dismal prognosis. At diagnosis, only 20% of patients with PDAC are eligible for primary resection. Neoadjuvant chemotherapy can enable surgical resection in 30%–40% of patients with locally advanced and borderline resectable PDAC. The effects of neoadjuvant chemotherapy on the cytokine production of tumor-infiltrating T cells are unknown in PDAC.METHODS We performed multiplex immunofluorescence to investigate T cell infiltration in 91 patients with PDAC. Using flow cytometry, we analyzed tumor and matched blood samples from 71 patients with PDAC and determined the frequencies of T cell subsets and their cytokine profiles. Both cohorts included patients who underwent primary resection and patients who received neoadjuvant chemotherapy followed by surgical resection.RESULTS In human PDAC, T cells were particularly enriched within the tumor stroma. Neoadjuvant chemotherapy markedly enhanced T cell density within the ductal area of the tumor. Whereas infiltration of cytotoxic CD8+ T cells was unaffected by neoadjuvant chemotherapy, the frequency of conventional CD4+ T cells was increased, and the proportion of Tregs was reduced in the pancreatic tumor microenvironment after neoadjuvant treatment. Moreover, neoadjuvant chemotherapy increased the production of proinflammatory cytokines by tumor-infiltrating T cells, with enhanced TNF-α and IL-2 and reduced IL-4 and IL-10 expression.CONCLUSION Neoadjuvant chemotherapy drives intratumoral T cells toward a proinflammatory profile. Combinational treatment strategies incorporating immunotherapy in neoadjuvant regimens may unleash more effective antitumor responses and improve prognosis of pancreatic cancer.FUNDING This work was supported by the Jung Foundation for Science and Research, the Monika Kutzner Foundation, the German Research Foundation (SE2980/5-1), the German Cancer Consortium, and the Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden.
Max Heiduk, Ioana Plesca, Jessica Glück, Luise Müller, David Digomann, Charlotte Reiche, Janusz von Renesse, Rahel Decker, Christoph Kahlert, Ulrich Sommer, Daniela E. Aust, Marc Schmitz, Jürgen Weitz, Lena Seifert, Adrian M. Seifert
Despite advances in ovarian cancer (OC) therapy, recurrent OC remains a poor-prognosis disease. Because of the close interaction between OC cells and the tumor microenvironment (TME), it is important to develop strategies that target tumor cells and engage components of the TME. A major obstacle in the development of OC therapies is the identification of targets with expression limited to tumor surface to avoid off-target interactions. The follicle-stimulating hormone receptor (FSHR) has selective expression on ovarian granulosa cells and is expressed on 50%–70% of serous OCs. We generated mAbs targeting the external domain of FSHR using in vivo–expressed FSHR vector. By high-throughput flow analysis, we identified multiple clones and downselected D2AP11, a potent FSHR surface–targeted mAb. D2AP11 identifies important OC cell lines derived from tumors with different mutations, including BRCA1/2, and lines resistant to a wide range of therapies. We used D2AP11 to develop a bispecific T cell engager. In vitro addition of PBMCs and T cells to D2AP11-TCE induced specific and potent killing of different genetic and immune escape OC lines, with EC50s in the ng/ml range, and attenuated tumor burden in OC-challenged mouse models. These studies demonstrate the potential utility of biologics targeting FSHR for OC and perhaps other FSHR-positive cancers.
Devivasha Bordoloi, Pratik S. Bhojnagarwala, Alfredo Perales-Puchalt, Abhijeet J. Kulkarni, Xizhou Zhu, Kevin Liaw, Ryan P. O’Connell, Daniel H. Park, Daniel W. Kulp, Rugang Zhang, David B. Weiner
The aberrant activation of STAT3 is associated with the etiology and progression in a variety of malignant epithelial-derived tumors, including head and neck squamous cell carcinoma (HNSCC) and colorectal cancer (CRC). Due to the lack of an enzymatic catalytic site or a ligand-binding pocket, there are no small-molecule inhibitors directly targeting STAT3 that have been approved for clinical translation. Emerging proteolysis targeting chimeric (PROTAC) technology–based approach represents a potential strategy to overcome the limitations of conventional inhibitors and inhibit activation of STAT3 and downstream genes. In this study, the heterobifunctional small-molecule–based PROTACs are successfully prepared from toosendanin (TSN), with 1 portion binding to STAT3 and the other portion binding to an E3 ubiquitin ligase. The optimized lead PROTAC (TSM-1) exhibits superior selectivity, potency, and robust antitumor effects in STAT3-dependent HNSCC and CRC — especially in clinically relevant patient-derived xenografts (PDX) and patient-derived organoids (PDO). The following mechanistic investigation identifies the reduced expression of critical downstream STAT3 effectors, through which TSM-1 promotes cell cycle arrest and apoptosis in tumor cells. These findings provide the first demonstration to our knowledge of a successful PROTAC-targeting strategy in STAT3-dependent epithelial cancer.
Jinmei Jin, Yaping Wu, Zeng Zhao, Ye Wu, Yu-dong Zhou, Sanhong Liu, Qingyan Sun, Guizhu Yang, Jiayi Lin, Dale G. Nagle, Jiangjiang Qin, Zhiyuan Zhang, Hong-zhuan Chen, Weidong Zhang, Shuyang Sun, Xin Luan
Metastatic clear cell renal cell carcinomas (ccRCC) are resistant to DNA damaging chemotherapies, limiting therapeutic options for patients whose tumours are resistant to tyrosine kinase inhibitors and/or immune checkpoint therapies. Here we show that mouse and human ccRCC are frequently characterised by high levels of endogenous DNA damage and that cultured ccRCC cells exhibit intact cellular responses to chemotherapy-induced DNA damage. We identify that pharmacological inhibition of the DNA damage sensing kinase ATR with the orally administered, potent and selective drug M4344 (also called gartisertib) induces anti-proliferative effects in ccRCC cells due to replication stress and the accumulation of DNA damage in S phase. In some cells, DNA damage persists into subsequent G2/M and G1 phases, leading to the frequent accumulation of micronuclei. Daily single agent treatment with M4344 inhibited the growth of ccRCC xenograft tumours. M4344 synergises with chemotherapeutic drugs including cisplatin and carboplatin and the PARP inhibitor olaparib in mouse and human ccRCC cells. Weekly M4344 plus cisplatin treatment showed in vivo therapeutic synergy in ccRCC xenografts and was efficacious in an autochthonous mouse ccRCC model. These studies identify ATR inhibition as a potential novel therapeutic option for ccRCC.
Philipp Seidel, Anne Rubarth, Kyra Zodel, Asin Peighambari, Felix Neumann, Yannick Federkiel, Hsin Huang, Rouven Hoefflin, Mojca Adlesic, Christian Witt, David J. Hoffmann, Patrick Metzger, Ralph K. Lindemann, Frank T. Zenke, Christoph Schell, Melanie Boerries, Dominik von Elverfeldt, Wilfried Reichardt, Marie Follo, Joachim Albers, Ian J. Frew
Chronic inflammation is associated with lung tumorigenesis, in which NF-κB-mediated epigenetic regulations play a critical role. Lung tumor suppressor GPRC5A is repressed in most non-small cell lung cancer (NSCLC), however the mechanisms remain unclear. Here, we show that NF-κB acts as a transcriptional repressor in suppression of GPRC5A. NF-κB induces GPRC5A repression both in vitro and in vivo. Intriguingly, trans-activation of NF-κB downstream targets is not required, but the trans-activation domain of RelA/p65 was required for GPRC5A repression. NF-κB did not bind to any potential cis-element in GPRC5A promoter. Instead, p65 was complexed with RARα/β, and recruited to the RA-response element (RARE) site at the GPRC5A promoter, resulting in disrupted RNA polymerase II complex, and suppressed transcription. Noticeably, phosphorylation on Serine276 of p65 is required for interaction with RARα/β and repression of GPRC5A. Moreover, NF-κB-mediated epigenetic repression is through suppression of histone H3K9ac, but not DNA methylation of the CpG islands, at the GPRC5A promoter. Consistently, a HDAC inhibitor, but not DNA methylation inhibitor, restored GPRC5A expression in NSCLC cells. Thus, NF-κB induces transcriptional repression of GPRC5A via complex with RARα/β and mediates epigenetic repression via suppression of H3K9ac.
Hongyong Song, Xiaofeng Ye, Yueling Liao, Siwei Zhang, Dongliang Xu, Shuangshuang Zhong, Bo Jing, Tong Wang, Beibei Sun, Jianhua Xu, Wenzheng Guo, Kaimi Li, Min Hu, Yanbin Kuang, Jing Ling, Tuo Zhang, Yadi Wu, Jing Du, Feng Yao, Yugene Chin, Qi Wang, Binhua P. Zhou, Jiong Deng
Despite the efficacy of tyrosine kinase inhibitors (TKIs) in chronic myeloid leukemia (CML), malignant long-term hematopoietic stem cells (LT-HSC) persist as a source of relapse. However, LT-HSC are heterogenous and the most primitive, drug-resistant LT-HSC subpopulations are not well characterized. In normal hematopoiesis, self-renewal and long-term reconstitution capacity is enriched within LT-HSCs with low c-Kit expression (c-KitLow). Here, using a transgenic CML mouse model, we found that long-term engraftment and leukemogenic capacity were restricted to c-KitLow CML LT-HSC. CML LT-HSC demonstrated enhanced differentiation with expansion of mature progeny following exposure to the c-Kit ligand, stem cell factor (SCF). Conversely, SCF deletion led to depletion of normal LT-HSC but increase in c-KitLow and total CML LT-HSC with reduced generation of mature myeloid cells. CML c-KitLow LT-HSC showed reduced cell cycling, and expressed enhanced quiescence and inflammatory gene signatures. SCF administration led to enhanced depletion of CML primitive progenitors but not LT-HSC after TKI treatment. Human CML LT-HSC with low or absent c-Kit expression were markedly enriched after TKI treatment. We conclude that CML LT-HSC expressing low c-Kit levels are enriched for primitive, quiescent, drug-resistant leukemia initiating cells and represent a critical target for eliminating disease persistence.
Mansi Shah, Harish Kumar, Shaowei Qiu, Hui Li, Mason Harris, Jianbo He, Ajay Abraham, David K. Crossman, Andrew Paterson, Robert S. Welner, Ravi Bhatia
One of the least-investigated areas of brain pathology research is glycosylation, which is a critical regulator of cell surface protein structure and function. β-Galactoside α2,6-sialyltransferase (ST6GAL1) is the primary enzyme that α2,6 sialylates N-glycosylated proteins destined for the plasma membrane or secretion, thereby modulating cell signaling and behavior. We demonstrate a potentially novel, protumorigenic role for α2,6 sialylation and ST6GAL1 in the deadly brain tumor glioblastoma (GBM). GBM cells with high α2,6 sialylation exhibited increased in vitro growth and self-renewal capacity and decreased mouse survival when orthotopically injected. α2,6 Sialylation was regulated by ST6GAL1 in GBM, and ST6GAL1 was elevated in brain tumor-initiating cells (BTICs). Knockdown of ST6GAL1 in BTICs decreased in vitro growth, self-renewal capacity, and tumorigenic potential. ST6GAL1 regulates levels of the known BTIC regulators PDGF Receptor β (PDGFRB), Activated Leukocyte Cell Adhesion Molecule, and Neuropilin, which were confirmed to bind to a lectin-recognizing α2,6 sialic acid. Loss of ST6GAL1 was confirmed to decrease PDGFRB α2,6 sialylation, total protein levels, and the induction of phosphorylation by PDGF-BB. Thus, ST6GAL1-mediated α2,6 sialylation of a select subset of cell surface receptors, including PDGFRB, increases GBM growth.
Sajina GC, Kaysaw Tuy, Lucas Rickenbacker, Robert Jones, Asmi Chakraborty, C. Ryan Miller, Elizabeth A. Beierle, Vidya Sagar Hanumanthu, Anh N. Tran, James A. Mobley, Susan L. Bellis, Anita B. Hjelmeland
Muscle weakness and wasting are defining features of cancer-induced cachexia. Mitochondrial stress occurs before atrophy in certain muscles, but the possibility of heterogeneous responses between muscles and across time remains unclear. Using mice inoculated with Colon-26 (C26) cancer, we demonstrate that specific force production was reduced in quadriceps and diaphragm at 2 weeks in the absence of atrophy. At this time, pyruvate-supported mitochondrial respiration was lower in quadriceps while mitochondrial H2O2 emission was elevated in diaphragm. By 4 weeks, atrophy occurred in both muscles, but specific force production increased to control levels in quadriceps such that reductions in absolute force were due entirely to atrophy. Specific force production remained reduced in diaphragm. Mitochondrial respiration increased and H2O2 emission was unchanged in both muscles vs control while mitochondrial creatine sensitivity was reduced in quadriceps. These findings indicate muscle weakness precedes atrophy and is linked to heterogeneous mitochondrial alterations that could involve adaptive responses to metabolic stress. Eventual muscle-specific restorations in force and bioenergetics highlight how the effects of cancer on one muscle do not predict the response in another muscle. Exploring heterogeneous responses of muscle to cancer may reveal new mechanisms underlying distinct sensitivities, or resistance, to cancer cachexia.
Luca J. Delfinis, Catherine A. Bellissimo, Shivam Gandhi, Sara N. DiBenedetto, Madison C. Garibotti, Arshdeep K. Thuhan, Stavroula Tsitkanou, Megan E. Rosa-Caldwell, Fasih A. Rahman, Arthur J. Cheng, Michael P. Wiggs, Uwe Schlattner, Joe Quadrilatero, Nicholas P. Greene, Christopher G.R. Perry
Oncogenic FOXO1 gene fusions drive a subset of rhabdomyosarcoma (RMS) with poor survival and to date these cancer drivers are therapeutically intractable. To identify new therapies for this disease, we undertook an isogenic CRISPR-interference screen to define PAX3-FOXO1 specific genetic dependencies and identified genes in the GATOR2 complex. GATOR2 loss in RMS abrogated amino acid-induced lysosomal localization of mTORC1 and consequent downstream signaling, slowing G1-S cell cycle transition. In vivo suppression of GATOR2 impaired the growth of tumor xenografts and favored the outgrowth of cells lacking PAX3-FOXO1. Loss of a subset of GATOR2 members can be compensated by direct genetic activation of mTORC1. RAS mutations are also sufficient to decouple mTORC1 activation from GATOR2, and indeed fusion negative RMS harboring such mutations exhibit amino acid-independent mTORC1 activity. A bi-steric, mTORC1-selective small molecule induced tumor regressions in fusion positive patient-derived tumor xenografts. These findings highlight a vulnerability in FOXO1 fusion positive RMS and provide rationale for the clinical evaluation of bi-steric mTORC1 inhibitors, currently in phase 1 testing, to treat this disease. Isogenic genetic screens can thus identify potentially exploitable vulnerabilities in fusion driven pediatric cancers which otherwise remain mostly undruggable.
Jacqueline Morales, David V. Allegakoen, José A. Garcia, Kristen Kwong, Pushpendra K. Sahu, Drew A. Fajardo, Yue Pan, Max A. Horlbeck, Jonathan S. Weissman, W. Clay Gustafson, Trever G. Bivona, Amit J. Sabnis
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