scholarly journals Enhancer Reprogramming Confers Dependence on Glycolysis and IGF signaling in KMT2D Mutant Melanoma

2018 ◽  
Author(s):  
Mayinuer Maitituoheti ◽  
Emily Z. Keung ◽  
Ming Tang ◽  
Liang Yan ◽  
Hunain Alam ◽  
...  

SUMMARYEpigenetic modifiers have emerged as important regulators of tumor progression. We identified histone methyltransferase KMT2D as a potent tumor-suppressor through an in vivo epigenome-focused pooled RNAi screen in melanoma. KMT2D harbors frequent somatic point mutations in multiple tumor types. How these events contribute to tumorigenesis and whether they impart therapeutic vulnerability are poorly understood. To address these questions, we generated a genetically engineered mouse model of melanoma based on conditional and melanocyte-specific deletion of KMT2D. We demonstrate KMT2D as a bona fide tumor suppressor which cooperates with activated BRAF. KMT2D-deficient tumors showed substantial reprogramming of key metabolic pathways including glycolysis. Glycolysis enzymes, intermediate metabolites and glucose consumption rate were aberrantly upregulated in KMT2D mutant cells. The pharmacological inhibition of glycolysis reduced proliferation and tumorigenesis preferentially in KMT2D mutant cells. Mechanistically, KMT2D loss caused drastic reduction of H3K4me1-marked active enhancer states. Loss of distal enhancer and subsequent reduction in expression of IGFBP5 activated IGF1R-AKT to increase glycolysis in KMT2D-deficient cells. We conclude that KMT2D loss promotes tumorigenesis by facilitating increased usage of glycolysis pathway for enhanced biomass needs via enhancer reprogramming. Our data imply that inhibition of glycolysis or IGFR pathway could be a potential therapeutic strategy in KMT2D mutant tumors.


2015 ◽  
Vol 112 (11) ◽  
pp. 3493-3498 ◽  
Author(s):  
Helen Y. Zou ◽  
Qiuhua Li ◽  
Lars D. Engstrom ◽  
Melissa West ◽  
Vicky Appleman ◽  
...  

Oncogenic c-ros oncogene1 (ROS1) fusion kinases have been identified in a variety of human cancers and are attractive targets for cancer therapy. The MET/ALK/ROS1 inhibitor crizotinib (Xalkori, PF-02341066) has demonstrated promising clinical activity in ROS1 fusion-positive non-small cell lung cancer. However, emerging clinical evidence has shown that patients can develop resistance by acquiring secondary point mutations in ROS1 kinase. In this study we characterized the ROS1 activity of PF-06463922, a novel, orally available, CNS-penetrant, ATP-competitive small-molecule inhibitor of ALK/ROS1. In vitro, PF-06463922 exhibited subnanomolar cellular potency against oncogenic ROS1 fusions and inhibited the crizotinib-refractory ROS1G2032Rmutation and the ROS1G2026Mgatekeeper mutation. Compared with crizotinib and the second-generation ALK/ROS1 inhibitors ceritinib and alectinib, PF-06463922 showed significantly improved inhibitory activity against ROS1 kinase. A crystal structure of the PF-06463922-ROS1 kinase complex revealed favorable interactions contributing to the high-affinity binding. In vivo, PF-06463922 showed marked antitumor activity in tumor models expressing FIG-ROS1, CD74-ROS1, and the CD74-ROS1G2032Rmutation. Furthermore, PF-06463922 demonstrated antitumor activity in a genetically engineered mouse model of FIG-ROS1 glioblastoma. Taken together, our results indicate that PF-06463922 has potential for treating ROS1 fusion-positive cancers, including those requiring agents with CNS-penetrating properties, as well as for overcoming crizotinib resistance driven by ROS1 mutation.



2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi121-vi121
Author(s):  
Daniel Zamler ◽  
Er-Yen Yen ◽  
Takashi Shingu ◽  
Jiangong Ren ◽  
Cynthia Kassab ◽  
...  

Abstract The introduction of immunotherapies has been paradigm shifting for cancers that were previously a death sentence. However, preclinical/clinical studies on glioblastoma (GBM) have generated mixed outcomes in patients, likely due to its great heterogeneity of immune microenvironment, particularly the myeloid cell populations. Primary patient studies have been limited by a difficulty in performing longitudinal studies, uncontrolled environmental conditions, and genetic variability. There is also, unfortunately, a paucity of mouse models that effectively re-capitulate the immune microenvironment of the human disease. To address these difficulties, we have established the Qk/p53/Pten (QPP) triple knockout mouse model established in our lab. The QPP model uses a cre-lox system to induce Qk deletion on a Pten−/−; p53−/− background which helps NSCs maintain their stemness outside the SVZ in Nes-CreERT2;QkiL/L PtenL/L p53L/L mice, which develops glioblastoma with survival of ~105 days. We have preliminarily assessed the QPP tumors as a faithful model to study the immune response to GBM and found them to recapitulate human GBM with respect to differential response to checkpoint blockade therapy and myeloid and T-cells histopathologically, particularly regarding upregulation of Arginase-1 (Arg1). Arg1 is the canonical marker for tumor-associated macrophages (TAMs), which is a major population of myeloid cells that greatly infiltrate in human GBM, sometimes making up more than ~30% of all GBM cells. Given TAMs’ prevalence in the tumor microenvironment and their upregulation of Arg1 in both human GBM and our QPP model, we are testing whether manipulation of Arg1 will impact TAM function and influence GBM growth. We are also evaluating arginine metabolism in TAMs effect on T cell function in GBM. Lastly, we have developed a genetically engineered mouse model to study the role of Arg1 knockout in a GBM context in-vivo. Our studies suggest that Arg1 plays an important role in GBM immune interaction.



2020 ◽  
Vol 124 (1) ◽  
pp. 161-165
Author(s):  
Nidhi Pamidimukkala ◽  
Gemma S. Puts ◽  
M. Kathryn Leonard ◽  
Devin Snyder ◽  
Sandrine Dabernat ◽  
...  

AbstractNME1 is a metastasis-suppressor gene (MSG), capable of suppressing metastatic activity in cell lines of melanoma, breast carcinoma and other cancer origins without affecting their growth in culture or as primary tumours. Herein, we selectively ablated the tandemly arranged Nme1 and Nme2 genes to assess their individual impacts on metastatic activity in a mouse model (HGF:p16−/−) of ultraviolet radiation (UVR)-induced melanoma. Metastatic activity was strongly enhanced in both genders of Nme1- and Nme2-null mice, with stronger activity in females across all genotypes. The study ascribes MSG activity to Nme2 for the first time in an in vivo model of spontaneous cancer, as well as a novel metastasis-suppressor function to Nme1 in the specific context of UVR-induced melanoma.



Small ◽  
2016 ◽  
Vol 12 (31) ◽  
pp. 4241-4253 ◽  
Author(s):  
Koo Chul Kwon ◽  
Ho Kyung Ko ◽  
Jiyun Lee ◽  
Eun Jung Lee ◽  
Kwangmeyung Kim ◽  
...  


2014 ◽  
Vol 21 (6) ◽  
pp. 879-890 ◽  
Author(s):  
Sebastian Krug ◽  
Benjamin Kühnemuth ◽  
Heidi Griesmann ◽  
Albrecht Neesse ◽  
Leonie Mühlberg ◽  
...  

Pancreatic neuroendocrine neoplasms (PNENs) constitute a rare tumour entity, and prognosis and treatment options depend on tumour-mediating hallmarks such as angiogenesis, proliferation rate and resistance to apoptosis. The molecular pathways that determine the malignant phenotype are still insufficiently understood and this has limited the use of effective combination therapies in the past. In this study, we aimed to characterise the effect of the oncogenic transcription factor Cut homeobox 1 (CUX1) on proliferation, resistance to apoptosis and angiogenesis in murine and human PNENs. The expression and function ofCUX1were analysed using knockdown and overexpression strategies in Ins-1 and Bon-1 cells, xenograft models and a genetically engineered mouse model of insulinoma (RIP1Tag2). Regulation of angiogenesis was assessed using RNA profiling and functional tube-formation assays in HMEC-1 cells. Finally,CUX1expression was assessed in a tissue microarray of 59 human insulinomas and correlated with clinicopathological data.CUX1expression was upregulated during tumour progression in a time- and stage-dependent manner in the RIP1Tag2 model, and associated with pro-invasive and metastatic features of human insulinomas. Endogenous and recombinantCUX1expression increased tumour cell proliferation, tumour growth, resistance to apoptosis, and angiogenesisin vitroandin vivo. Mechanistically, the pro-angiogenic effect ofCUX1was mediated via upregulation of effectors such as HIF1α and MMP9.CUX1mediates an invasive pro-angiogenic phenotype and is associated with malignant behaviour in human insulinomas.



2020 ◽  
Author(s):  
Jesse Balic ◽  
Hassan Albargy ◽  
Kevin Luu ◽  
Francis J Kirby ◽  
W. Samantha N. Jayasekara ◽  
...  

ABSTRACTDetection of microbial components such as lipopolysaccharide (LPS) by Toll-like receptor (TLR)-4 expressed on macrophages induces a robust pro-inflammatory response which has recently been shown to be dependent on metabolic reprogramming 1, 2, 3, 4. These innate metabolic changes have been compared to the Warburg effect (also known as aerobic glycolysis) described in tumour cells 5, 6. However, the mechanisms by which TLR4 activation leads to mitochondrial and glycolytic reprogramming remain unknown. Here we show that TLR4 activation induces a signalling cascade recruiting TRAF6 and TBK-1, while TBK-1 phosphorylates STAT3 on S727. Using a genetically engineered mouse model incapable of undergoing STAT3 Ser727 phosphorylation, we show both ex vivo and in vivo that STAT3 Ser727 phosphorylation is critical for LPS-induced glycolytic reprogramming, the production of the central immune-metabolite succinate and inflammatory cytokine production in a model of LPS-induced inflammation. Our study identifies non-canonical STAT3 activation as the crucial signalling intermediary for TLR4-induced glycolysis, macrophage metabolic reprogramming and inflammation.



2019 ◽  
Vol 218 (6) ◽  
pp. 1943-1957 ◽  
Author(s):  
Dawid G. Nowak ◽  
Ksenya Cohen Katsenelson ◽  
Kaitlin E. Watrud ◽  
Muhan Chen ◽  
Grinu Mathew ◽  
...  

Metastatic prostate cancer commonly presents with targeted, bi-allelic mutations of the PTEN and TP53 tumor suppressor genes. In contrast, however, most candidate tumor suppressors are part of large recurrent hemizygous deletions, such as the common chromosome 16q deletion, which involves the AKT-suppressing phosphatase PHLPP2. Using RapidCaP, a genetically engineered mouse model of Pten/Trp53 mutant metastatic prostate cancer, we found that complete loss of Phlpp2 paradoxically blocks prostate tumor growth and disease progression. Surprisingly, we find that Phlpp2 is essential for supporting Myc, a key driver of lethal prostate cancer. Phlpp2 dephosphorylates threonine-58 of Myc, which renders it a limiting positive regulator of Myc stability. Furthermore, we show that small-molecule inhibitors of PHLPP2 can suppress MYC and kill PTEN mutant cells. Our findings reveal that the frequent hemizygous deletions on chromosome 16q present a druggable vulnerability for targeting MYC protein through PHLPP2 phosphatase inhibitors.



2020 ◽  
Author(s):  
Teresa Cramer ◽  
Raminder Gill ◽  
Zahra S Thirouin ◽  
Markus Vaas ◽  
Suchita Sampath ◽  
...  

AbstractMicroglia interact with neurons to facilitate synapse plasticity; however, signal transducers between microglia and neuron remain unknown. Here, using in vitro organotypic hippocampal slice cultures and transient MCAO in genetically-engineered mice in vivo, we report that at 24 h post-ischemia microglia release BDNF to downregulate glutamatergic and GABAergic synapses within the peri-infarct area. Analysis of the CA1 hippocampal formation in vitro shows that proBDNF and mBDNF downregulate glutamatergic dendritic spines and gephyrin scaffold stability through p75NTR and TrkB receptors respectively. Post-MCAO, we report that in the peri- infarct area and in the corresponding contralateral hemisphere similar neuroplasticity occur through microglia activation and gephyrin phosphorylation at Ser268, Ser270 in vivo. Targeted deletion of the Bdnf gene in microglia or GphnS268A/S270A (phospho-null) point-mutations protect against ischemic brain damage, neuroinflamation and synapse downregulation normally seen post-MCAO. Collectively, we report that gephyrin phosphorylation and microglia derived BDNF faciliate synapse plasticity after transient ischemia.



2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Yan Wang ◽  
Liangying Dan ◽  
Qianqian Li ◽  
Lili Li ◽  
Lan Zhong ◽  
...  

Abstract Background Recent studies suggested that ZMYND10 is a potential tumor suppressor gene in multiple tumor types. However, the mechanism by which ZMYND10 inhibits breast cancer remains unclear. Here, we investigated the role and mechanism of ZMYND10 in breast cancer inhibition. Results ZMYND10 was dramatically reduced in multiple breast cancer cell lines and tissues, which was associated with promoter hypermethylation. Ectopic expression of ZMYND10 in silenced breast cancer cells induced cell apoptosis while suppressed cell growth, cell migration and invasion in vitro, and xenograft tumor growth in vivo. Furthermore, molecular mechanism studies indicated that ZMYND10 enhances expression of miR145-5p, which suppresses the expression of NEDD9 protein through directly targeting the 3'-untranslated region of NEDD9 mRNA. Conclusions Results from this study show that ZMYND10 suppresses breast cancer tumorigenicity by inhibiting the miR145-5p/NEDD9 signaling pathway. This novel discovered signaling pathway may be a valid target for small molecules that might help to develop new therapies to better inhibit the breast cancer metastasis.



2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii230-ii231
Author(s):  
Diana Shi ◽  
Adam Wang ◽  
Wenhua Gao ◽  
Januka Khanal ◽  
Michael Levitt ◽  
...  

Abstract Despite the high prevalence of IDH1-R132H mutations in lower grade gliomas, the ability to study this mutation in vivo has been hampered by a lack of faithful mouse models. Therefore, we used a CRISPR/Cas9- and AAV-based strategy to create a genetically engineered mouse model (GEMM) of astrocytoma driven by IDH1-R132H that recreates the genetic landscape of human IDH1 mutant astrocytoma. IDH1 mutations in astrocytomas often co-occur with mutations in TP53, ATRX, and either PIK3R1 or PIK3CA. Using human astrocytes immortalized via expression of telomerase (which phenocopies ATRX loss) and HPV E6 and E7 oncoproteins (which phenocopy p53 and pRb loss, respectively), we found that PIK3R1 and IDH1 oncogenes cooperate to promote anchorage-independent cell growth in vitro and orthotopic brain tumor formation in vivo. These data identified a combination of clinically relevant mutations that we hypothesized could be leveraged to cause spontaneous astrocytoma formation in mice. To simultaneously engineer Idh1, Pik3ca, Tp53, and Atrx mutations in mouse brain tissue, we intracranially injected adeno-associated virus (AAV) expressing Cre recombinase and sgRNAs targeting murine Atrx and Tp53 genes into four mouse strains with the following conditional alleles: 1) LSL-Cas9; 2) LSL-Cas9; LSL-Pik3caH1047R, 3) LSL-Cas9; LSL-Idh1R132H, and 4) LSL-Cas9; LSL-Idh1R132H; LSL-Pik3caH1047R. Grade III anaplastic astrocytomas preferentially formed 9-14 months after injecting the mice carrying both the Idh1 and Pik3ca conditional alleles. These astrocytomas harbored all intended mutations, expressed astrocytoma lineage markers, and displayed elevated (R)-2-hydroxyglutarate, the oncometabolite produced by mutant Idh1. To create an additional model with shorter tumor latency, we transplanted glioma stem-like cells derived from our GEMM into recipient mice to produce Idh1 mutant astrocytoma allografts. These allografts provide a tractable platform for preclinical therapeutic studies. Taken together, our findings show that IDH1 and PI3K oncoproteins cooperate to promote gliomagenesis and unveil new genetically faithful mouse models of mutant IDH1-driven astrocytoma.



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