EPCO-18. A MESENCHYMAL CELL POPULATION MEDIATES RESISTANCE TO AURORA KINASE INHIBITORS IN GLIOBLASTOMA

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi5-vi5
Author(s):  
Robert Suter ◽  
Vasileios Stathias ◽  
Anna Jermakowicz ◽  
Hari Pradhyumnan ◽  
Maurizio Affer ◽  
...  

Abstract Glioblastoma (GBM) remains the most common adult brain cancer, with a dismal average patient survival of less than two years. No new treatments have been approved for GBM since the introduction of the alkylating agent temozolomide in 2005. Even then, temozolomide treatment only increases the average survival of GBM patients by a few months. Thus, novel therapeutic options are direly needed. The aurora kinases A and B are targetable and overexpressed in GBM, and their expression is highly correlated with patient survival outcomes. Our lab has found that small molecule aurora kinase inhibition reduces GBM tumor growth in vitro and in vivo, however, eventually tumors still grow. Computational analysis integrating compound transcriptional response signatures from the LINCS L1000 dataset with the single-cell RNA-sequencing data of patient GBM tumors resected at the University of Miami predicts that aurora inhibition targets a subset of cells present within any GBM tumor. Results of in vivo single-cell perturbation experiments with the aurora kinase inhibitor alisertib coincide with our predictions and reveal a cellular transcriptional phenotype resistant to aurora kinase inhibition, characterized by a mesenchymal expression program. We find that small molecules that are predicted to target different cell populations from alisertib, including this resistant mesenchymal population, synergize with alisertib to kill GBM cells. As a whole, we have identified the cellular population resistant to aurora kinase inhibition and have developed an analytical framework that identifies synergistic small molecule combinations by identifying compounds that target transcriptionally distinct cellular populations within GBM tumors.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 641-641 ◽  
Author(s):  
Suzanne Trudel ◽  
Zhi Hua Li ◽  
Ellen Wei ◽  
Marion Wiesmann ◽  
Katherine Rendahl ◽  
...  

Abstract The t(4;14) translocation that occurs uniquely in a subset (15%) of multiple myeloma (MM) patients results in the ectopic expression of the receptor tyrosine kinase, Fibroblast Growth Factor Receptor3 (FGFR3). Wild-type FGFR3 induces proliferative signals in myeloma cells and appears to be weakly transforming in a hematopoeitic mouse model. The subsequent acquisition of FGFR3 activating mutations in some MM is associated with disease progression and is strongly transforming in several experimental models. The clinical impact of t(4;14) translocations has been demonstrated in several retrospective studies each reporting a marked reduction in overall survival. We have previously shown that inhibition of activated FGFR3 causes morphologic differentiation followed by apoptosis of FGFR3 expressing MM cell lines, validating activated FGFR3 as a therapeutic target in t(4;14) MM and encouraging the clinical development of FGFR3 inhibitors for the treatment of these poor-prognosis patients. CHIR258 is a small molecule kinase inhibitor that targets Class III–V RTKs and inhibits FGFR3 with an IC50 of 5 nM in an in vitro kinase assay. Potent anti-tumor and anti-angiogenic activity has been demonstrated in vitro and in vivo. We employed the IL-6 dependent cell line, B9 that has been engineered to express wild-type FGFR3 or active mutants of FGFR3 (Y373C, K650E, G384D and 807C), to screen CHIR258 for activity against FGFR3. CHIR258 differentially inhibited FGF-mediated growth of B9 expressing wild-type and mutant receptors found in MM, with an IC50 of 25 nM and 80 nM respectively as determined by MTT proliferation assay. Growth of these cells could be rescued by IL-6 demonstrating selectivity of CHIR258 for FGFR3. We then confirmed the activity of CHIR258 against FGFR3 expressing myeloma cells. CHIR258 inhibited the viability of FGFR3 expressing KMS11 (Y373C), KMS18 (G384D) and OPM-2 (K650E) cell lines with an IC50 of 100 nM, 250 nM and 80 nM, respectively. Importantly, inhibition with CHIR258 was still observed in the presence of IL-6, a potent growth factors for MM cells. U266 cells, which lack FGFR3 expression, displayed minimal growth inhibition demonstrating that at effective concentrations, CHIR258 exhibits minimal nonspecific cytotoxicity on MM cells. Further characterization of this finding demonstrated that inhibition of cell growth corresponded to G0/G1 cell cycle arrest and dose-dependent inhibition of downstream ERK phosphorylation. In responsive cell lines, CHIR258 induced apoptosis via caspase 3. In vitro combination analysis of CHIR258 and dexamethasone applied simultaneously to KMS11 cells indicated a synergistic interaction. In vivo studies demonstrated that CHIR258 induced tumor regression and inhibited growth of FGFR3 tumors in a plasmacytoma xenograft mouse model. Finally, CHIR258 produced cytotoxic responses in 4/5 primary myeloma samples derived from patients harboring a t(4;14) translocation. These data indicate that the small molecule inhibitor, CHIR258 potently inhibits FGFR3 and has activity against human MM cells setting the stage for a Phase I clinical trial of this compound in t(4;14) myeloma.


2002 ◽  
Vol 22 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Fuhu Wang ◽  
Dale Corbett ◽  
Hitoshi Osuga ◽  
Sachiko Osuga ◽  
Joh-E Ikeda ◽  
...  

Increasing evidence suggests that cyclin-dependent kinases participate in neuronal death induced by multiple stresses in vitro. However, their role in cell death paradigms in vivo is not well characterized. Accordingly, the authors examined whether cyclin-dependent kinase inhibition resulted in functionally relevant and sustained neuroprotection in a model of global ischemia. Intracerebroventricular administration of the cyclin-dependent kinase inhibitor flavopiridol, immediately or at 4 hours postreperfusion after a global insult, reduced injury in the CA1 of the hippocampus when examined 7 days after reperfusion. No significant protection was observed when flavopiridol was administered 8 hours after reperfusion. The tumor-suppressor retinoblastoma protein, a substrate of cyclin-dependent kinase, was phosphorylated on a cyclin-dependent kinase consensus site after the global insult; this phosphorylation was inhibited by flavopiridol administration. Importantly, flavopiridol had no effect on core body temperature, suggesting that the mechanism of neuroprotection was through cyclin-dependent kinase inhibition but not through hypothermia. Furthermore, inhibition of cyclin-dependent kinases improved spatial learning behavior as assessed by the Morris water maze 7 to 9 days after reperfusion. However, the histologic protection observed at day 7 was absent 28 days after reperfusion. These results indicate that cyclin-dependent kinase inhibition provides an extended period of morphologic and functional neuroprotection that may allow time for other neuroprotective modalities to be introduced.


2020 ◽  
Author(s):  
Khairul Ansari ◽  
Arunoday Bhan ◽  
Mike Chen ◽  
Rahul Jandial

Abstract Leptomeningeal carcinomatosis (LC), when tumor cells spread to leptomeninges surrounding the brain and spinal cord. HER2+ breast cancer is the most common origin of LC. HER2+ LC remains incurable, with few treatment options and response rates of <20%. One major limitation in development of HER2+ LC therapies has been lack of clinically relevant HER2+ LC primary cell-lines and animal models. To address this, we generated cell lines and patient-derived xenograft models using nodular HER2+ LC. This led to identification of granulocyte-macrophage colony-stimulating factor (GM-CSF) as an oncogenic autocrine driver of HER2+ LC. We observed that oligodendrocyte progenitor cells (OPCs) inhibit growth of HER2+ LC in vitro and in vivo. Furthermore, OPC-derived factor TPP1 degrades GM-CSF, decreasing GM-CSF signaling and suppressing HER2+ LC growth. Lastly, we determined that synergistic inactivation of GM-CSF signaling via the intrathecal delivery neutralizing anti-GM-CSF antibodies and a pan-Aurora kinase inhibitor (CCT137690) antagonizes development of HER2+ LC in vivo.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anna M. Jermakowicz ◽  
Matthew J. Rybin ◽  
Robert K. Suter ◽  
Jann N. Sarkaria ◽  
Zane Zeier ◽  
...  

AbstractBromodomain and extraterminal domain (BET) proteins have emerged as therapeutic targets in multiple cancers, including the most common primary adult brain tumor glioblastoma (GBM). Although several BET inhibitors have entered clinical trials, few are brain penetrant. We have generated UM-002, a novel brain penetrant BET inhibitor that reduces GBM cell proliferation in vitro and in a human cerebral brain organoid model. Since UM-002 is more potent than other BET inhibitors, it could potentially be developed for GBM treatment. Furthermore, UM-002 treatment reduces the expression of cell-cycle related genes in vivo and reduces the expression of invasion related genes within the non-proliferative cells present in tumors as measured by single cell RNA-sequencing. These studies suggest that BET inhibition alters the transcriptional landscape of GBM tumors, which has implications for designing combination therapies. Importantly, they also provide an integrated dataset that combines in vitro and ex vivo studies with in vivo single-cell RNA-sequencing to characterize a novel BET inhibitor in GBM.


2020 ◽  
Vol 177 (12) ◽  
pp. 2848-2859
Author(s):  
Li‐Na Zhang ◽  
Kunmei Ji ◽  
Yue‐Tong Sun ◽  
Yi‐Bo Hou ◽  
Jia‐Jie Chen

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Paul Guilhamon ◽  
Charles Chesnelong ◽  
Michelle M Kushida ◽  
Ana Nikolic ◽  
Divya Singhal ◽  
...  

Chromatin accessibility discriminates stem from mature cell populations, enabling the identification of primitive stem-like cells in primary tumors, such as Glioblastoma (GBM) where self-renewing cells driving cancer progression and recurrence are prime targets for therapeutic intervention. We show, using single-cell chromatin accessibility, that primary human GBMs harbor a heterogeneous self-renewing population whose diversity is captured in patient-derived glioblastoma stem cells (GSCs). In depth characterization of chromatin accessibility in GSCs identifies three GSC states: Reactive, Constructive, and Invasive, each governed by uniquely essential transcription factors and present within GBMs in varying proportions. Orthotopic xenografts reveal that GSC states associate with survival, and identify an invasive GSC signature predictive of low patient survival, in line with the higher invasive properties of Invasive state GSCs compared to Reactive and Constructive GSCs as shown by in vitro and in vivo assays. Our chromatin-driven characterization of GSC states improves prognostic precision and identifies dependencies to guide combination therapies.


2020 ◽  
Vol 7 ◽  
Author(s):  
Lingfang Zhuang ◽  
Lin Lu ◽  
Ruiyan Zhang ◽  
Kang Chen ◽  
Xiaoxiang Yan

Advances in single-cell RNA sequencing (scRNA-seq) technology have recently shed light on the molecular mechanisms of the spatial and temporal changes of thousands of cells simultaneously under homeostatic and ischemic conditions. The aim of this study is to investigate whether it is possible to integrate multiple similar scRNA-seq datasets for a more comprehensive understanding of diseases. In this study, we integrated three representative scRNA-seq datasets of 27,349 non-cardiomyocytes isolated at 3 and 7 days after myocardial infarction or sham surgery. In total, seven lineages, including macrophages, fibroblasts, endothelia, and lymphocytes, were identified in this analysis with distinct dynamic and functional properties in healthy and nonhealthy hearts. Myofibroblasts and endothelia were recognized as the central hubs of cellular communication via ligand-receptor interactions. Additionally, we showed that macrophages from different origins exhibited divergent transcriptional signatures, pathways, developmental trajectories, and transcriptional regulons. It was found that myofibroblasts predominantly expand at 7 days after myocardial infarction with pro-reparative characteristics. We identified signature genes of myofibroblasts, such as Postn, Cthrc1, and Ddah1, among which Ddah1 was exclusively expressed on activated fibroblasts and exhibited concordant upregulation in bulk RNA sequencing data and in vivo and in vitro experiments. Collectively, this compendium of scRNA-seq data provides a valuable entry point for understanding the transcriptional and dynamic changes of non-cardiomyocytes in healthy and nonhealthy hearts by integrating multiple datasets.


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