scholarly journals TMOD-15. EFFICACY OF THE MDM2 INHIBITOR KRT-232 IN GLIOBLASTOMA PATIENT-DERIVED XENOGRAFT MODELS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii231-ii231
Author(s):  
Rachael Vaubel ◽  
Ann Mladek ◽  
Yu Zhao ◽  
Shiv K Gupta ◽  
Minjee Kim ◽  
...  
Keyword(s):  
Target Genes ◽  
Xenograft Model ◽  
Culture Conditions ◽  
Patient Derived Xenograft ◽  
Fold Induction ◽  
Extended Survival ◽  
Mdm2 Amplification ◽  
Mdm2 Inhibitor

Abstract Non-genotoxic reactivation of p53 by MDM2 inhibitors represents a promising therapeutic strategy for tumors with wild-type TP53, particularly tumors harboring MDM2 amplification. MDM2 controls p53 levels by targeting it for degradation, while disruption of the MDM2-p53 interaction causes rapid accumulation of p53 and activation of the p53 pathway. We examined the efficacy of the small molecule MDM2 inhibitor KRT-232, alone and in combination with radiation therapy (RT), in MDM2-amplified and/or p53 wildtype patient-derived xenograft (PDX) models of glioblastoma in vitro and in vivo. In vitro, glioblastoma PDX explant cultures showed sensitivity to KRT-232, both tumors with MDM2 amplification (GBM108 and G148) and non-amplified but TP53-wildtype lines (GBM10, GBM14, and GBM39), with IC50s ranging from 300-800 nM in FBS culture conditions. A TP53 p.F270C mutant PDX (GBM43) was inherently resistant, with IC50 >3000 nM. In the MDM2-amplified GBM108 line, KRT-232 led to a robust (5-6 fold) induction of p53-target genes p21, PUMA, and NOXA, with initiation of both apoptosis and senescence. Expression of p21 and PUMA was greater with KRT-232 in combination with RT (25-35 fold induction), while stable knock-down of p53 in GBM108 led to complete resistance to KRT-232. In contrast, GBM10 showed lower induction of p21 and PUMA (2-3 fold) and was more resistant to KRT-232. In an orthotopic GBM108 xenograft model, treatment with KRT-232 +/- RT for one week extended survival from 22 days (placebo) to 46 days (KRT-232 alone); combination KRT-232 + RT further extended survival (77 days) over RT alone (31 days). KRT-232 is an effective treatment in a subset of glioblastoma pre-clinical models alone and in combination with RT. Further studies are underway to understand the mechanisms conferring innate sensitivity or resistance to KRT-232.

scholarly journals EXTH-46. ARTIFICIAL INTELLIGENCE-BASED IDENTIFICATION OF COMBINED VANDETANIB AND EVEROLIMUS IN THE TREATMENT OF ACVR1-MUTANT DIFFUSE INTRINSIC PONTINE GLIOMA

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii97-ii97
Author(s):  
Diana Carvalho ◽  
Peter Richardson ◽  
Nagore Gene Olaciregui ◽  
Reda Stankunaite ◽  
Cinzia Emilia Lavarino ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Cell Viability ◽  
Xenograft Model ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Pontine Glioma ◽  
Serine Threonine Kinase ◽  
Orthotopic Xenografts ◽  
Extended Survival

Abstract Somatic mutations in ACVR1, encoding the serine/threonine kinase ALK2 receptor, are found in a quarter of children with the currently incurable brain tumour diffuse intrinsic pontine glioma (DIPG). Treatment of ACVR1-mutant DIPG patient-derived models with multiple inhibitor chemotypes leads to a reduction in cell viability in vitro and extended survival in orthotopic xenografts in vivo, though there are currently no specific ACVR1 inhibitors licensed for DIPG. Using an Artificial Intelligence-based platform to search for approved compounds which could be used to treat ACVR1-mutant DIPG, the combination of vandetanib and everolimus was identified as a possible therapeutic approach. Vandetanib, an approved inhibitor of VEGFR/RET/EGFR, was found to target ACVR1 (Kd=150nM) and reduce DIPG cell viability in vitro, but has been trialed in DIPG patients with limited success, in part due to an inability to cross the blood-brain-barrier. In addition to mTOR, everolimus inhibits both ABCG2 (BCRP) and ABCB1 (P-gp) transporter, and was synergistic in DIPG cells when combined with vandetanib in vitro. This combination is well-tolerated in vivo, and significantly extended survival and reduced tumour burden in an orthotopic ACVR1-mutant patient-derived DIPG xenograft model. Based on these preclinical data, three patients with ACVR1-mutant DIPG were treated with vandetanib and everolimus. These cases may inform on the dosing and the toxicity profile of this combination for future clinical studies. This bench-to-bedside approach represents a rapidly translatable therapeutic strategy in children with ACVR1 mutant DIPG.

scholarly journals NUSAP1 Promotes Gastric Cancer Progression Through Regulation of Yap Stability

2020 ◽  
Author(s):  
Hui Guo ◽  
Jianping Zou ◽  
Ling Zhou ◽  
Yan He ◽  
Miao Feng ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Progression ◽  
Target Genes ◽  
Hippo Pathway ◽  
Critical Role ◽  
Xenograft Model ◽  
Migration And Invasion

Abstract Background:Nucleolar and spindle associated protein (NUSAP1) is involved in tumor initiation, progression and metastasis. However, there are limited studies regarding the role of NUSAP1 in gastric cancer (GC). Methods: The expression profile and clinical significance of NUSAP1 in GC were analysed in online database using GEPIA, Oncomine and KM plotter, which was further confirmed in clinical specimens.The functional role of NUSAP1 were detected utilizing in vitro and in vivo assays. Western blotting, qRT-PCR, the cycloheximide-chase, immunofluorescence staining and Co-immunoprecipitaion (Co-IP) assays were performed to explore the possible molecular mechanism by which NUSAP1 stabilizes YAP protein. Results:In this study, we found that the expression of NUSAP1 was upregulated in GC tissues and correlates closely with progression and prognosis. Additionally, abnormal NUSAP1 expression promoted malignant behaviors of GC cells in vitro and in a xenograft model. Mechanistically, we discovered that NUSAP1 physically interacts with YAP and furthermore stabilizes YAP protein expression, which induces the transcription of Hippo pathway downstream target genes. Furthermore, the effects of NUSAP1 on GC cell growth, migration and invasion were mainly mediated by YAP. Conclusions:Our data demonstrates that the novel NUSAP1-YAP axis exerts an critical role in GC tumorigenesis and progression, and therefore could provide a novel therapeutic target for GC treatment.

scholarly journals Hypoxia-mediated carbohydrate metabolism and transport promote early-stage murine follicle growth and survival

2014 ◽  
Vol 306 (8) ◽  
pp. E893-E903 ◽  
Author(s):  
Yogeshwar Makanji ◽  
David Tagler ◽  
Jennifer Pahnke ◽  
Lonnie D. Shea ◽  
Teresa K. Woodruff
Keyword(s):  
Target Genes ◽  
Early Stage ◽  
Fold Increase ◽  
Underlying Mechanism ◽  
Culture Conditions ◽  
Follicle Growth ◽  
Growth And Survival ◽  
Lactate Levels

Oxygen tension is critical for follicle growth and metabolism, especially for early-stage follicles, where vascularity is limited. Its role and underlying mechanism in the in vitro activation and maturation of immature to ovulatory follicles is largely unknown. In this study, early secondary (110 μm) murine follicles were isolated and encapsulated in alginate hydrogels to replicate the in vivo environment of the growing/maturing follicle. Encapsulated follicles were cultured for 8 days at either 2.5 or 20% O2. Survival (2.6-fold) and growth (1.2-fold) were significantly higher for follicles cultured at 2.5% compared with 20% O2. Using a mouse hypoxia-signaling pathway qRT-PCR array and GeneGo Metacore analysis, we found that direct target genes of the hypoxia-activated HIF1-complex were significantly upregulated in follicles cultured for 8 days at 2.5% compared with 20% O2, including the carbohydrate transport and metabolism genes Slc2a3, Vegfa, Slc2a1, Edn1, Pgk1, Ldha, and Hmox1. Other upregulated genes included carbohydrate transporters ( Slc2a1, Slc2a3, and Slc16a3) and enzymes essential for glycolysis ( Pgk1, Hmox1, Hk2, Gpi1, Pfkl, Pfkp, Aldoa, Gapdh, Pgam1, Eno1, Pkm2, and Ldha). For follicles cultured at 2.5% O2, a 7.2-fold upregulation of Vegfa correlated to an 18-fold increase in VEGFA levels, and a 3.2-fold upregulation of Ldha correlated to a 4.8-fold increase in lactate levels. Both VEGFA and lactate levels were significantly higher in follicles cultured at 2.5% compared with 20% O2. Therefore, enhanced hypoxia-mediated glycolysis is essential for growth and survival of early secondary follicles and provides vital insights into improving in vitro culture conditions.

scholarly journals Induction of Truncating ASXL1 Mutations in Human CD34+ HSPCs Mimics Human ASXL1-Mutated Clonal Hematopoiesis and Progression to Myeloid Malignancies

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 820-820
Author(s):  
Thomas Koehnke ◽  
Rajiv Sharma ◽  
Yusuke Nakauchi ◽  
Andreas Reinisch ◽  
Ravi Majeti
Keyword(s):  
Cord Blood ◽  
Target Genes ◽  
Xenograft Model ◽  
Human Cord Blood ◽  
Myeloid Malignancies ◽  
Clonal Hematopoiesis ◽  
Recurrent Mutations ◽  
Proliferative Advantage

Introduction: Mutations in additional sex combs like 1 (ASXL1) are recurrently found in myeloid malignancies including myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), but can also be found in pre-malignant states such as clonal hematopoiesis of indeterminate potential (CHIP). However, the mechanisms by which these mutations contribute to disease initiation and progression remain unresolved. Initial observations using murine models suggested a loss of function of the ASXL1 protein as relevant to disease. However more recently, several studies have suggested that recurrent mutations of ASXL1 result in a change-of function caused by a truncated ASXL1 protein. Most of these studies have been performed in a murine system and have used over-expression of truncated ASXL1. Methods: To interrogate the functional relevance of recurrent mutations in ASXL1 in human HSPCs, we generated a novel CRISPR/Cas9-mediated model that allows for the introduction of truncations or complete knockout of ASXL1 into CD34+ cord blood cells. Importantly, this is the first model which efficiently introduces these mutations into the native ASXL1 locus in human cord-blood and bone-marrow derived HSPCs while simultaneously introducing a fluorescent marker corresponding to the genotype, so individual cells can be tracked in vitro and in vivo. Results: Using this system, we demonstrate that truncated, but not deleted, ASXL1 shows a proliferative advantage, decreased ability to differentiate along the megakaryocyte and erythroid lineages, as well as increased serial replating in vitro. Interestingly, truncation of ASXL1 alone did not result in a myeloid differentiation block in vitro, in line with observations of mutant HSPCs in CHIP. In vivo, CD34+ cells harboring truncation of ASXL1 exhibited myeloid skewing and a proliferative advantage in competitive engraftment studies using a xenograft NSGS mouse model (both p<0.05). Human HSPCs expressing truncated ASXL1 showed polyclonal engraftment without development of overt myeloid disease or impaired lifespan in the majority of the host animals. However, similar to humans with ASXL1 CHIP, some of the engrafted animals (2/30) developed clonal expansion of ASXL1-truncated human HSPCs resulting in a myeloid-biased, proliferative disease-like state with infiltration of non-hematopoietic organs and severe cytopenia which ultimately led to shortened survival of affected mice. Functionally, ASXL1-truncated HSPCs displayed dysregulated gene expression with depletion of RUNX1, TAL1, and GATA1 target genes (Benjamini-Hochberg adjusted p<0.0001). In line with increased activity of the Polycomb repressive deubiquitinase complex, truncation of ASXL1, but not deletion, led to decreased H2AK119Ub in our system (MFI ratio 0.7 for truncated ASXL1 vs. control, p<0.05). Orthogonally, we were able to confirm these observations in several isogenic cell lines engineered to contain truncating ASXL1 mutations as well as correcting the mutation in ASXL1 found in K562 cells (Y591*) using CRISPR/Cas9. Finally, we aimed to determine whether the introduction of additional mutations commonly observed to co-occur with ASXL1 could alter the behavior of human HSPCs and their progression from healthy hematopoiesis to myeloid disease. Indeed, introduction of mutations in the native RUNX1 locus on the background of truncated ASXL1 showed aggressive expansion of immature myeloid progenitors in our xenograft model. This system allows us now to determine the relevant genomic target regions of truncated ASXL1 in human HSPCs, investigate the mechanism of action directly in the relevant biological system and identify therapeutic strategies targeting mutant ASXL1. Conclusion: In summary, our work demonstrates the utilization of a novel CRISPR/Cas9 model of human ASXL1-mutant HSPCs that closely resembles the phenotype seen in individuals with ASXL1 mutant CHIP and patients with myeloid malignancies carrying mutant ASXL1. Additionally, our model allows us to directly compare the deletion of ASXL1 with the truncation, adding to the evidence that truncated ASXL1 phenocopies pre-malignant and malignant hematopoiesis with recurrent ASXL1 mutations. Finally, we provide the first model for the spontaneous progression of pre-malignant human CHIP to myeloid malignancy, which should enable further studies of leukemogenesis and potentially disease prevention. Disclosures Majeti: FortySeven: Consultancy, Equity Ownership, Other: Board of Director; BioMarin: Consultancy.

scholarly journals Erratum

2021 ◽  
Vol 28 (6) ◽  
pp. 681-682
Author(s):  
Juan Gu ◽  
Chang-fu Cui ◽  
Li Yang ◽  
Ling Wang ◽  
Xue-hua Jiang
Keyword(s):  
Signaling Pathway ◽  
Target Genes ◽  
Mrna Level ◽  
Xenograft Model ◽  
Dependent Manner ◽  
Invasion And Migration ◽  
Downstream Target ◽  
And Migration

Colon cancer (CC) is the third most common cancer worldwide. Emodin is an anthraquinone-active substance that has the ability to affect tumor progression. Our study aims to explore the effects and the relevant mechanism of emodin on the invasion and migration of CC in vitro and in vivo. In our study, we found that emodin inhibited the invasion and migration abilities of RKO cells and decreased the expression of matrix metalloproteinase-7 (MMP-7), MMP-9, and vascular endothelial growth factor (VEGF) in a dose-dependent manner. Further research suggested that emodin inhibited EMT by increasing the mRNA level of E-cadherin and decreasing the expression of N-cadherin, Snail, and -catenin. Emodin also significantly inhibited the activation of the Wnt/-catenin signaling pathway by downregulating the expression of related downstream target genes, including TCF4, cyclin D1, and c-Myc. A Wnt/-catenin signaling pathway agonist abolished the effect of emodin on EMT and cell mobility, suggesting that emodin exerted its regulating role through the Wnt/-catenin pathway. The CC xenograft model was established to study the antitumor efficiency of emodin in vivo. The in vivo study further demonstrated that emodin (40 mg/kg) suppressed tumor growth by inhibiting EMT via the Wnt/-catenin signaling pathway in vivo. Taken together, we suggest that emodin inhibits the invasion and migration of CC cells in vitro and in vivo by blocking EMT, which is related with the inhibition of the Wnt/-catenin signaling pathway.

scholarly journals Palbociclib and Ponatinib Suppress Acute Myeloid Leukemia in Patient-Derived Xenograft

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4461-4461
Author(s):  
Daniel Busa ◽  
Tomas Loja ◽  
Ivana Jeziskova ◽  
Adam Folta ◽  
Jiri Mayer ◽  
...  
Keyword(s):  
Acute Myeloid Leukemia ◽  
Myeloid Leukemia ◽  
Disease Burden ◽  
Xenograft Model ◽  
Final Analysis ◽  
Lymphoid Leukemia ◽  
Patient Derived Xenograft ◽  
Acute Myeloid

Abstract Aims: Palbociclib, a breast cancer approved CDK4/6 inhibitor, and ponatinib, a BCR/ABL1 inhibitor with a multi-kinase activity approved for chronic myeloid and acute lymphoid leukemia, were previously shown to be effective in vitro against acute myeloid leukemia (AML). Here, we aimed to test this effect in a patient-derived xenograft model. Methods: Two newly diagnosed AMLs (AML #1: myelomonocytic AML, intermediate cytogenetic risk; AML #2: AML with myelodysplasia-related changes, poor cytogenetic risk) were xenotransplanted into NOD SCID gamma mice. Treatment was initiated at detection of approximately 5-20% hCD45+ cells in mouse peripheral blood (PB). Palbociclib, ponatinib, vehicle, and venetoclax as a comparative treatment, were administered orally for 3 weeks, 5 days per week. Chemotherapy (cytarabine+doxorubicine, AraC/Dox) 5+3 regimen served as a positive control. Azacitidine served as another comparative drug and was administered subcutaneously, five days per week in 3 cycles - 1 week on, 1 week off. Results: Significant reduction of disease burden and prolongation of overall survival (OS) were seen with palbociclib and the reference treatment venetoclax in both AMLs, and with chemotherapy in AML#1 (Fig. 1). Ponatinib prolonged OS in AML#1 but failed to provide reduction of disease burden in PB. Interestingly, azacitidine induced the longest remission (<1% hCD45+ cells in PB), for almost 10 weeks, but only in 2/4 mice for AML#2. Treatment toxicity manifested by weight decrease was only seen with chemotherapy (AML#1: 24% weight loss, p = 0.0001; AML#2: 19% loss, p = 0.04), and was also accompanied with early mouse mortality in 3/4 mice for AML#2. None of the tested treatments lead to complete AML eradication and a gradual relapse was seen in PB. The AML infiltration was higher in bone marrow than in spleen at final analysis at relapse (AML#1, 83 vs 73% of hCD45+ cells, mean, p = 0.02; AML#2, 95 vs 65%, p = 0.0001). No changes in AML phenotype were observed between treated and vehicle mice in case of AML#1, except for azacitidine which decreased monocyte (SSCdim, CD45high; 94 vs 96%, mean, p = 0.03), CD34+ (2 vs 5%, p = 0.01) and primitive CD34+CD38- cell (0.1 vs 0.3%, p = 0.005) percentages. For AML#2, blast (SSClow, CD45dim) percentage compared to vehicle (70%) was decreased by chemotherapy (24%, p = 0.01) and increased by venetoclax (80%, p = 0.03) and azacitidine (87%, p = 0.03); monocytes (6% for vehicle) were decreased by chemotherapy (1%, p = 0.004), venetoclax (3%, p = 0.01), and azacitidine (0%, p = 0.008); CD34+ cells were increased by venetoclax (59 vs 39%, p = 0.02). Summary: Palbociclib, and partially ponatinib, demonstrated AML suppression in vivo. This encourages further investigation of their efficacy in different AML subtypes and in combination with other drugs. Funding: Supported by MUNI/A/1595/2020. Figure 1 Figure 1. Disclosures Mayer: AOP Orphan Pharmaceuticals: Research Funding.

scholarly journals Oncogenic lncRNA ZNF561-AS1 is essential for colorectal cancer proliferation and survival through regulation of miR-26a-3p/miR-128-5p-SRSF6 axis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zizhen Si ◽  
Lei Yu ◽  
Haoyu Jing ◽  
Lun Wu ◽  
Xidi Wang
Keyword(s):  
Colorectal Cancer ◽  
Rna Binding ◽  
Xenograft Model ◽  
Luciferase Reporter ◽  
Cancer Proliferation ◽  
Mouse Xenograft ◽  
Mouse Xenograft Model

Abstract Background Long non-coding RNAs (lncRNA) are reported to influence colorectal cancer (CRC) progression. Currently, the functions of the lncRNA ZNF561 antisense RNA 1 (ZNF561-AS1) in CRC are unknown. Methods ZNF561-AS1 and SRSF6 expression in CRC patient samples and CRC cell lines was evaluated through TCGA database analysis, western blot along with real-time PCR. SRSF6 expression in CRC cells was also examined upon ZNF561-AS1 depletion or overexpression. Interaction between miR-26a-3p, miR-128-5p, ZNF561-AS1, and SRSF6 was examined by dual luciferase reporter assay, as well as RNA binding protein immunoprecipitation (RIP) assay. Small interfering RNA (siRNA) mediated knockdown experiments were performed to assess the role of ZNF561-AS1 and SRSF6 in the proliferative actives and apoptosis rate of CRC cells. A mouse xenograft model was employed to assess tumor growth upon ZNF561-AS1 knockdown and SRSF6 rescue. Results We find that ZNF561-AS1 and SRSF6 were upregulated in CRC patient tissues. ZNF561-AS1 expression was reduced in tissues from treated CRC patients but upregulated in CRC tissues from relapsed patients. SRSF6 expression was suppressed and enhanced by ZNF561-AS1 depletion and overexpression, respectively. Mechanistically, ZNF561-AS1 regulated SRSF6 expression by sponging miR-26a-3p and miR-128-5p. ZNF561-AS1-miR-26a-3p/miR-128-5p-SRSF6 axis was required for CRC proliferation and survival. ZNF561-AS1 knockdown suppressed CRC cell proliferation and triggered apoptosis. ZNF561-AS1 depletion suppressed the growth of tumors in a model of a nude mouse xenograft. Similar observations were made upon SRSF6 depletion. SRSF6 overexpression reversed the inhibitory activities of ZNF561-AS1 in vivo, as well as in vitro. Conclusion In summary, we find that ZNF561-AS1 promotes CRC progression via the miR-26a-3p/miR-128-5p-SRSF6 axis. This study reveals new perspectives into the role of ZNF561-AS1 in CRC.

scholarly journals Edelfosine nanoemulsions inhibit tumor growth of triple negative breast cancer in zebrafish xenograft model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sofia M. Saraiva ◽  
Carlha Gutiérrez-Lovera ◽  
Jeannette Martínez-Val ◽  
Sainza Lores ◽  
Belén L. Bouzo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Growth ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Xenograft Model ◽  
Skin Barrier ◽  
Zebrafish Embryos ◽  
Biorelevant Media

AbstractTriple negative breast cancer (TNBC) is known for being very aggressive, heterogeneous and highly metastatic. The standard of care treatment is still chemotherapy, with adjacent toxicity and low efficacy, highlighting the need for alternative and more effective therapeutic strategies. Edelfosine, an alkyl-lysophospholipid, has proved to be a promising therapy for several cancer types, upon delivery in lipid nanoparticles. Therefore, the objective of this work was to explore the potential of edelfosine for the treatment of TNBC. Edelfosine nanoemulsions (ET-NEs) composed by edelfosine, Miglyol 812 and phosphatidylcholine as excipients, due to their good safety profile, presented an average size of about 120 nm and a neutral zeta potential, and were stable in biorelevant media. The ability of ET-NEs to interrupt tumor growth in TNBC was demonstrated both in vitro, using a highly aggressive and invasive TNBC cell line, and in vivo, using zebrafish embryos. Importantly, ET-NEs were able to penetrate through the skin barrier of MDA-MB 231 xenografted zebrafish embryos, into the yolk sac, leading to an effective decrease of highly aggressive and invasive tumoral cells’ proliferation. Altogether the results demonstrate the potential of ET-NEs for the development of new therapeutic approaches for TNBC.

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