JS01.3.A Oncogenic chaperoning of Hsp90 in glioma with FGFR3-TACC3

2021 ◽  
Vol 23 (Supplement_2) ◽  
pp. ii4-ii5
Author(s):  
T Li ◽  
F Mehraein-Ghomi ◽  
M Forbes ◽  
S Namjoshi ◽  
E Ballard ◽  
...  
Keyword(s):  
Dna Damage ◽  
Fusion Gene ◽  
Xenograft Model ◽  
Fold Increase ◽  
Hsp90 Inhibitor ◽  
Glioblastoma Cells ◽  
Hsp90 Inhibitors ◽  
System Combination ◽  
Before And After

Abstract BACKGROUND Fusion genes are chromosomal aberrations in malignancies that can be used as prognostic markers as well as therapeutic targets. The FGFR3-TACC3 (F3-T3) was initially discovered as an oncogenic molecule in glioblastoma and bladder cancer and subsequently found in many other cancer types. Based on clinical evidence, F3-T3 was found in glioblastoma patients before and after TMZ and radiotherapy treatment, suggesting that targeting F3-T3 is a valid strategy for glioblastoma treatment. MATERIAL AND METHODS We profiled the proteins that interacted with F3-T3 fusion protein in U-251 MG cells with F3-T3 through 2-D liquid chromatography-tandem mass spectrometry. To validate the result of proteomic analysis, we performed reverse immunoprecipitation by pulling down Hsp90 or Cdc37 in U-251 MG cells stably expressing F3-T3. To inhibit the association between F3-T3 and the Hsp90-Cdc37 complex, we treated U-251 MG and LN-229 cells stably expressing F3-T3 with Hsp90 inhibitors or siRNA of Cdc37. We applied the CCK8 assay to evaluate the sensitivity of glioblastoma cells stably expressing F3-T3, wild-type FGFR3, kinase-dead F3-T3 (K508R), and empty vectors to TMZ. Immunoblot and immunofluorescence staining were used to detect DNA damage marker pH2AX. The drug combination effect index was analyzed using software CalcuSyn. U-251 MG cells stably expressing F3-T3 infected with luciferase virus were intracranially injected in nude mice. The experimental group was administered with temozolomide (5mg/kg/day) by oral gavage, Hsp90 inhibitor Onalespib (30mg/kg/day) by tail vein injection or the combination of the two for indicated days. RESULTS We identified the proteins that showed increased binding ratios to F3-T3 over full-length FGFR3, the molecular chaperone proteins encoded by the genes HSP90AB1, HSP90AA1, and CDC37 emerged as 5th, 6th, and 7th on the top ten list, showing an approximately 4-fold increase in normalized spectral counts. Using Hsp90 inhibitors or Cdc37 siRNA disrupted the formation of the F3-T3/Hsp90/Cdc37 complex. Disruption of Hsp90-Cdc37 chaperoning caused a ubiquitination-mediated degradation of the glycosylated form of F3-T3 and abrogated the maturation of nascent F3-T3, resulting in suppression of F3-T3 signaling pathways. Additionally, our results provide evidence that the F3-T3 signaling pathway confers drug resistance to TMZ induced DNA damage. However, the resistance of TMZ was disrupted in glioblastoma cells harboring kinase-dead F3-T3 (K508R). We also demonstrated Hsp90 inhibitor significantly sensitized glioblastoma cells harboring the F3-T3 fusion gene to TMZ treatment and improved survival of xenograft model bearing F3-T3 tumor in vivo. CONCLUSION F3-T3 is a strong Hsp90 client that shows strong addiction to the Hsp90-Cdc37 chaperone system. Combination therapy with Hsp90 inhibitor overcomes the TMZ resistance conferred by F3-T3.

scholarly journals A Novel Benzopyrane Derivative Targeting Cancer Cell Metabolic and Survival Pathways

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2840
Author(s):  
Dana M. Zaher ◽  
Wafaa S. Ramadan ◽  
Raafat El-Awady ◽  
Hany A. Omar ◽  
Fatema Hersi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cancer Cell ◽  
Xenograft Model ◽  
Mitochondrial Metabolism ◽  
High Dose ◽  
Anticancer Effect ◽  
Safety Margins ◽  
Wide Range

(1) Background: Today, the discovery of novel anticancer agents with multitarget effects and high safety margins represents a high challenge. Drug discovery efforts indicated that benzopyrane scaffolds possess a wide range of pharmacological activities. This spurs on building a skeletally diverse library of benzopyranes to identify an anticancer lead drug candidate. Here, we aim to characterize the anticancer effect of a novel benzopyrane derivative, aiming to develop a promising clinical anticancer candidate. (2) Methods: The anticancer effect of SIMR1281 against a panel of cancer cell lines was tested. In vitro assays were performed to determine the effect of SIMR1281 on GSHR, TrxR, mitochondrial metabolism, DNA damage, cell cycle progression, and the induction of apoptosis. Additionally, SIMR1281 was evaluated in vivo for its safety and in a xenograft mice model. (3) Results: SIMR1281 strongly inhibits GSHR while it moderately inhibits TrxR and modulates the mitochondrial metabolism. SIMR1281 inhibits the cell proliferation of various cancers. The antiproliferative activity of SIMR1281 was mediated through the induction of DNA damage, perturbations in the cell cycle, and the inactivation of Ras/ERK and PI3K/Akt pathways. Furthermore, SIMR1281 induced apoptosis and attenuated cell survival machinery. In addition, SIMR1281 reduced the tumor volume in a xenograft model while maintaining a high in vivo safety profile at a high dose. (4) Conclusions: Our findings demonstrate the anticancer multitarget effect of SIMR1281, including the dual inhibition of glutathione and thioredoxin reductases. These findings support the development of SIMR1281 in preclinical and clinical settings, as it represents a potential lead compound for the treatment of cancer.

Abstract 424: Vascular Smooth Muscle Cell Expression of S100a12 in Vivo Induces Enhanced Oxidative Stress & Vascular Remodeling

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Marion Hofmann Bowman ◽  
Jeannine Wilk ◽  
Gene Kim ◽  
Yanmin Zhang ◽  
Jalees Rehman ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dna Damage ◽  
Smooth Muscle ◽  
Vascular Remodeling ◽  
Oxidative Dna Damage ◽  
Fold Increase ◽  
Brdu Incorporation ◽  
Elastic Fibers ◽  
Nuclear Staining

S100A12 is a small calcium binding protein that is a signal transduction ligand of the receptor for advance glycation endproducts (RAGE). S100A12, like RAGE, is expressed in the vessel wall of atherosclerotic vasculature, particularly in smooth muscle cells (SMC). While RAGE has been extensively implicated in inflammatory states such as atherosclerosis, the role of S100A12 is less clear. We tested the hypothesis that expression of human S100A12 directly exacerbates vascular inflammation. Several lines of Bl6/J transgenic mice (tg) expressing human S100A12 in SMC under control of the SM22a promoter were generated. Primary aortic SMC from tg and wild type (wt) littermates were isolated and analyzed for (i) proliferation using MTS/Formazan Assay and BrdU incorporation, (ii) oxidative stress using using flow cytometry with MitoSOX antibody, oxidative DNA damage using immunofluorescence microscopy with anti-8-oxo-dG antibody, and NF-kB activation measured by EMSA and (iii) cytokine expression measured by IL-6 ELISA. Furthermore, the aortas from tg and wt mice were examined. Results: Tg but not wt SMC expressed S100A12 protein. Tg SMC had a significant 1.9 to 2.7 fold increase in conversion of MTS into Formazan at 24–96 hours likely reflective of increased metabolic activity since BrdU incorporation into DNA was less in tg compared to wt SMC (4% vs 21% positive BrdU nuclei, p <0.05). Tg SMC showed significantly higher levels of mitochondrial generated ROS, nuclear staining for oxidative DNA damage which was not detected in the nuclei of wt SMC’s, and a 2.5 fold increase in NFkB activity. IL-6 production at baseline was higher in tg SMC’s (615 vs 213 pg/ml, p< 0.05) and increased dramatically after LPS treatment (10 ng/ml) in tg SMC’s (2130 vs 415 pg/ml). Histologic examination of the thoracic aorta at 10 weeks of age revealed increased collagen deposition in the aortic media with fragmentation and disarray of elastic fibers. In vivo ultrasound revealed a progressive dilation of the aortic arch from age 10 weeks to 16 weeks of age (1.27 to 1.60 mm, p<0.05) in tg but not in wt littermate mice (1.30 to 1.33 mm, p=0.1). These data reveal the novel finding that targeted expression of human S100A12 in SMC modulates oxidative stress, inflammation and vascular remodeling.

scholarly journals Identification of Hsp90 inhibitors as potential drugs for the treatment of TSC1/TSC2 deficient cancer

2021 ◽  
Author(s):  
Evelyn M. Mrozek ◽  
Vineeta Bajaj ◽  
Yanan Guo ◽  
Izabela Malinowska ◽  
Jianming Zhang ◽  
...  
Keyword(s):  
Cell Lines ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Xenograft Model ◽  
Growth Delay ◽  
Hsp90 Inhibitors ◽  
Null Cell ◽  
Standard Dosage

Inactivating mutations in either TSC1 or TSC2 cause Tuberous Sclerosis Complex, an autosomal dominant disorder, characterized by multi-system tumor and hamartoma development. Mutation and loss of function of TSC1 and/or TSC2 also occur in a variety of sporadic cancers, and rapamycin and related drugs show highly variable treatment benefit in patients with such cancers. The TSC1 and TSC2 proteins function in a complex that inhibits mTORC1, a key regulator of cell growth, which acts to enhance anabolic biosynthetic pathways. In this study, we identified and validated five cancer cell lines with TSC1 or TSC2 mutations and performed a kinase inhibitor drug screen with 197 compounds. The five cell lines were sensitive to several mTOR inhibitors, and cell cycle kinase and HSP90 kinase inhibitors. The IC50 for Torin1 and INK128, both mTOR kinase inhibitors, was significantly increased in three TSC2 null cell lines in which TSC2 expression was restored.  Rapamycin was significantly more effective than either INK128 or ganetespib (an HSP90 inhibitor) in reducing the growth of TSC2 null SNU-398 cells in a xenograft model. Combination ganetespib-rapamycin showed no significant enhancement of growth suppression over rapamycin. Hence, although HSP90 inhibitors show strong inhibition of TSC1/TSC2 null cell line growth in vitro, ganetespib showed little benefit at standard dosage in vivo. In contrast, rapamycin which showed very modest growth inhibition in vitro was the best agent for in vivo treatment, but did not cause tumor regression, only growth delay.

scholarly journals Silencing VEGF enhances the radiosensitivity of the radioresistant human nasopharyngeal carcinoma cell line CNE-2R by inhibiting autophagy through the activation of mTOR pathway

2020 ◽  
Author(s):  
Li Chen ◽  
Guoxiang Lin ◽  
Kaihua Chen ◽  
Fangzhu Wan ◽  
Yongchu Sun ◽  
...  
Keyword(s):  
Dna Damage ◽  
Nasopharyngeal Carcinoma ◽  
Cell Line ◽  
Western Blotting ◽  
Xenograft Model ◽  
Mtor Pathway ◽  
Angiogenic Factor ◽  
Cell Counting

Abstract Background: Vascular endothelial growth factor (VEGF) is an important pro-angiogenic factor. VEGF was reported to promote the occurrence of autophagy, which enhanced to the radioresistance of tumors. The purpose of our study was to investigate the influence of VEGF silencing on the radiosensitivity of nasopharyngeal carcinoma radioresistant cell line CNE-2R and the underlying mechanisms.Methods: The radiosensitivity of CNE-2R cells after silencing VEGF was detected by cell counting kit 8 (CCK-8) and clonogenic assay, cell cycle and apoptosis was subjected to flow cytometry. DNA damage and autophagy were observed by immunofluorescence and western blotting. The interaction between VEGF and mTOR was confirmed by western blotting and co-immunoprecipitation analysis. In vivo, the effect of VEGF on radiosensitivity of NPC cells was investigated through xenograft model, furthermore, immunohistochemistry and TUNEL assay were used to further verify the relationship between autophagy and radiosensitivity in NPC after VEGF depletion.Results: Downregulation of VEGF significantly inhibited cell proliferation and induced apoptosis of CNE-2R cells after radiotherapy in vitro and in vivo. In addition, VEGF knockdown not only decreased autophagy level, but also delayed the DNA damage repair in CNE-2R cells after irradiation. Mechanistically, silencing VEGF suppressed autophagy through the activation of mTOR pathway.Conclusion: VEGF depletion increased radiosensitivity of NPC radioresistant cell CNE-2R by suppressing autophagy via the activation of mTOR pathway.

Intermittent, Repetitive Corticosteroid-Induced Upregulation of Platelet Levels After Adenovirus-Mediated Transfer to the Liver of a Chimeric Glucocorticoid-Responsive Promoter Controlling the Thrombopoietin cDNA

Blood ◽  
1998 ◽  
Vol 92 (3) ◽  
pp. 822-833 ◽  
Author(s):  
Ko Narumi ◽  
Motoyoshi Suzuki ◽  
Wenru Song ◽  
Malcolm A.S. Moore ◽  
Ronald G. Crystal
Keyword(s):  
Clinical Medicine ◽  
Intraperitoneal Administration ◽  
Fold Increase ◽  
Inducible Promoter ◽  
Pharmacologic Agent ◽  
Before And After ◽  
American Society ◽  
Pharmacologic Agents

Abstract For many in vivo gene therapy clinical applications, it is desirable to control the expression of the transferred transgene using pharmacologic agents. To evaluate the feasibility of accomplishing this using corticosteroids, pharmacologic agents widely used in clinical medicine, we constructed replication deficient adenoviral (Ad) vectors containing an expression cassette with a chimeric promoter comprised of five glucocorticoid response elements (GRE) and the chloramphenicol acetyltransferase reporter gene (AdGRE.CAT) or the murine thrombopoietin cDNA (AdGRE.mTPO). In vitro studies showed the vectors functioned as expected, with marked glucocorticoid-induced upregulation of the CAT or mTPO transgenes. To evaluate the inducibility of the GRE promoter in vivo, the AdGRE.CAT vector was administered intravenously to C57B1/6 mice, and CAT activity was quantified in liver before and after intraperitoneal administration of dexamethasone. The GRE promoter activity was dependent on the dexamethasone dose, with a 100-fold increase in CAT expression with 50 μg dexamethasone, similar to the levels observed in vivo with the Rous sarcoma virus long terminal repeat constitutive promoter. After dexamethasone administration, maximum CAT activity was observed at day 2, with a slow decline to baseline levels by 2 weeks. Based on these observations, we hypothesized that a single administration of an Ad vector-mediated transfer of the chimeric GRE inducible promoter driving the mTPO cDNA would enable repetitive administration of corticosteroids to repetitively upregulate platelet levels for 1 to 2 weeks. The data show that this occurs, with dexamethasone administration every 3 weeks associated with 1-week elevations (at each 3-week interval) of serum mTPO levels, megakaryocyte numbers in bone marrow, and platelet levels fourfold to sixfold over baseline. Thus, with the appropriate promoter, it is possible to use a commonly used pharmacologic agent to upregulate the expression of a newly transferred gene on demand. © 1998 by The American Society of Hematology.

Optimizing Mobilization, Augmentation, and Gene Transfer of Multipotent Mesenchymal Stromal Cells (MSCs).

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2555-2555
Author(s):  
Stephen R. Larsen ◽  
Keefe Chng ◽  
Shangzhen Zhou ◽  
John Wright ◽  
Margaret Armstrong ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Gene Transfer ◽  
Fold Increase ◽  
Multipotent Mesenchymal Stromal Cells ◽  
Transduction Efficiency ◽  
Human Mscs ◽  
Differentiation Potential ◽  
Development Factor ◽  
Before And After

Abstract Aims: MSCs are cells being investigated for use in various therapies including facilitation of HSC transplantation and as gene therapy delivery vehicles. We have explored the potential to increase the number of bone marrow (BM) MSCs in vivo, induce mobilization using various cytokine regimens and improve gene transfer into these cells with adeno-associated virus (AAV) in a baboon model. Method: Baboons received cytokines as follows: 1. G-CSF 100mcg/kg/day for 5 days; 2. pegylated G-CSF (pegG-CSF), single dose 300mcg/kg day −5; 3. G-CSF 100mcg/kg/day + stem cell factor (SCF) 50mcg/kg/day for 5 days; and 4. pegylated megakaryocyte growth and development factor (pegMGDF) 1mcg/kg second daily for 10 days + G-CSF 100mcg/kg/day for 5 days starting day −5. Animals underwent BM aspiration at baseline and on the final day of cytokines along with leukapheresis to isolate PBMNCs for detection of peripheral blood (PB) CFU-F. The immunophenotype and differentiation potential of CFU-F derived from animals before and after cytokines was compared. The ability of AAV vectors pseudotyped with capsids derived from AAV of serotypes 1, 2, 3, 4, 5, 6, and 8 to mediate transduction of baboon and human MSCs was assessed. Results: Augmentation of bone marrow MSCs was observed with all cytokine regimens with the fold-increase compared to baseline as follows: 4.1, 2.1, 7.6 and 11.2 after G-CSF, pegG-CSF, G-CSF+SCF and G-CSF+pegMGDF respectively (see Figure 1). The immunophenotype of MSCs obtained after cytokines was identical to baseline cells as was their differentation potential. CFU-F were not detected in baseline PB however they were detected in 3/5 animals after G-CSF+SCF at a frequency of 0.8 to 1.5/mL, but no other cytokine regimen. A similar pattern of transduction efficiency using AAV was shared by human and baboon MSCs (see Figure 2) using control Ad293 cells. Specifically AAV vectors expressing capsids of serotypes 2, 3 and 5 were most efficient in transducing human and baboon MSCs. Those expressing capsids from serotypes 1, 4, 6, and 8 were much less efficient in transducing MSCs from either species. Baboon MSCs were able to be transduced by about 100-fold more than their human equivalent cells using AAV serotypes 2, 3, and 5. Conclusion: This is the first report of mobilization of primate MSCs and, together with the demonstration of in vivo augmentation and AAV gene transfer, offers increased therapeutic opportunities for their safe application in a burgeoning number of diseases. Figure 1: In vivo Bone Marrow CFU-F Augmentation following cytokines Figure 1:. In vivo Bone Marrow CFU-F Augmentation following cytokines Figure 2: Transduction profile of AAV vectors expressing capsids of various serotypes Figure 2:. Transduction profile of AAV vectors expressing capsids of various serotypes

Preclinical Evaluation of A Potent 2nd Generation Small-Molecule Hsp90 Inhibitor STA-9090 In Hematological Cell Lines

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 2899-2899
Author(s):  
Weiwen Ying ◽  
David Proia ◽  
Suqin He ◽  
Jim Sang ◽  
Kevin Foley ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Small Molecule ◽  
First Generation ◽  
Cell Lymphoma ◽  
Hsp90 Inhibitor ◽  
Phase 2 ◽  
Hsp90 Inhibitors

Abstract Abstract 2899 STA-9090 is a potent, second generation, small-molecule Hsp90 inhibitor, with a chemical structure unrelated to the first-generation, ansamycin family of Hsp90 inhibitors. In preclinical in vitro and in vivo studies, STA-9090 has shown potency up to 100 times greater than the first-generation Hsp90 inhibitors against a wide range of solid and hematological cancer types including those resistant to imatinib, sunitinib, erlotinib, and dasatinib. STA-9090 is currently being evaluated two Phase 1 and four Phase 2 trials (non-small cell lung, GIST, colon, and gastric) in solid tumor cancers; and two trials in hematologic cancers. Additional Phase 2 trials in several other indications are planned for 2H 2010. Inhibition of Hsp90 by STA-9090 results in the destabilization of a broad range of oncogenic kinases often overexpressed or mutated in hematological cancers. For example, the nucleophosmin-anaplastic lymphoma kinase (NPM-ALK) expressed in the anaplastic large cell lymphoma (ALCL) cell line Karpas 299, is degraded rapidly in the presence of STA-9090 in vitro, resulting in the loss of viability. Similar results were shown in other NPM-ALK driven ALCL cells including SU-DHL-1 and SR-786 with IC50 less than 20 nM. Stability of other kinases common to hematological malignancies, such as Bcr-Abl, FLT3 and c-Kit, were also shown to be highly sensitive to STA-9090, resulting in potent cell death of cell lines addicted to signaling by these kinases. In vivo, STA-9090 was highly effective in a subcutaneous xenograft model of diffuse large B-cell lymphoma SU-DHL-4 with resulting %T/C values of 26, 4, -90 and -93 when dosed at 25, 50, 75 and 100 mg twice per week, respectively. Importantly, 75 and 100 mg/kg STA-9090 dosed 2 times per week for a total of 3 weeks (150 and 200 mg/kg weekly) resulted in 25% and 50% of the animals in each group being free of tumors by the end of the study, respectively. MV4-11, an AML (FLT3ITD) cell line, turned out to be one of the most sensitive xenograft models to STA-9090 treatment. STA-9090 at 100 mg/kg or125mg/kg once weekly was highly efficacious with 37.5% of mice achieving tumor free with acceptable toxicity at the end of the 3-week treatment period. In conclusion, STA-9090 exhibits preferable biological profiles both in vitro and in vivo in treating hematological malignances. Clinical studies for using STA-9090 both once weekly and twice weekly are ongoing. Disclosures: Ying: Synta Pharmaceuticals: Employment. Proia:Synta Pharmaceuticals: Employment. He:Synta Pharmaceur: Employment. Sang:Synta Pharmaceuticals: Employment. Foley:Synta Pharmaceuticals: former employee. Du:Synta Pharmaceuticals: former employee. Blackman:Synta Pharmaceuticals: Employment. Wada:Synta Pharmaceuticals: Employment. Sun:Synta Pharmaceuticals: Employment. Koya:Synta Pharmaceuticals: Employment.

Azacitidine/Decitabine Synergism with the NEDD8-Activating Enzyme Inhibitor MLN4924 in Pre-Clinical AML Models

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 578-578 ◽  
Author(s):  
Peter G Smith ◽  
Tary Traore ◽  
Steve Grossman ◽  
Usha Narayanan ◽  
Jennifer S Carew ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Death ◽  
Synthetic Lethality ◽  
Single Agent ◽  
Xenograft Model ◽  
S Phase ◽  
Myelogenous Leukemia ◽  
Phase Accumulation

Abstract Abstract 578 MLN4924 is an investigational small molecule inhibitor of NEDD8-activating enzyme that has shown clinical activity in a Phase I clinical trial in Acute Myelogenous Leukemia (AML). To identify potential combination partners of MLN4924 we performed a high-throughput viability screen in AML cells with 40 approved and investigational agents. In vitro characterization of AML cell lines revealed two distinct cell cycle phenotypes suggesting alternate mechanism of action following MLN4924 inhibition of NAE. One group demonstrated moderate S-phase accumulation with greater than 4N DNA content consistent with DNA-rereplication as a result of CDT1 dysregulation. The second group demonstrated distinct and rapid accumulation of subG1 cells without S-phase accumulation or DNA re-replication suggesting induction of apoptosis and cell death. These observations led us to choose two cells lines representative of each mechanism to understand potential for synergy in AML cells. Two hypomethylating agents were included in the screen (decitabine and azacitidine) and were found to be synergistic with MLN4924 by Combination Index and Blending Synergy Analysis. These data were confirmed with a second NAE inhibitor that is structurally dissimilar to MLN4924. The combination of azacitidine and MLN4924 were shown to result in significantly increased DNA-damage and cell death compared to single agent alone as measured by Western Blotting and FACS analysis of cell cycle distributions. In vivo studies were performed in HL-60 and THP-1 xenografts using MLN4924 on a clinically relevant dosing schedule twice weekly. Single agent azacitidine at its Maximum Tolerated Dose (MTD) had minimal activity in the HL-60 model and was combined with a sub-optimal dose of MLN4924 that when combined induced complete and sustained tumor regressions. The mechanism for the apparent synthetic lethality in this in vivo model is currently under evaluation; however it is supported by a dramatic elevation in DNA damage and cleaved caspase-3 in vivo in the combination arm. A second xenograft model (THP-1) that was also insensitive to single agent azacitidine treatment underwent complete and sustained tumor regressions when combined with MLN4924. Thus MLN4924 and azacitidine can combine to produce synergistic antitumor activity in pre-clinical models of AML. Coupled with their non-overlapping clinical toxicities these data suggest the potential for future combination studies in clinical trials. Disclosures: Smith: Millennium Pharmaceuticals: Employment. Traore:Millennium Pharmaceuticals: Employment. Grossman:Millennium Pharmaceuticals: Employment. Narayanan:Millennium Pharmaceuticals: Employment. Carew:Millennium Pharmaceuticals: Research Funding. Lublinksky:Millennium Pharmaceuticals: Employment. Kuranda:Millennium Pharmaceuticals: Employment. Milhollen:Millennium Pharmaceuticals: Employment.

scholarly journals In Vivo Mechanisms of Chemotherapy-Induced Acute Follicle Loss in the Human Ovary: An Individual-Oocyte Transcriptomic Analysis from Human Ovarian Xenografts

2020 ◽  
Author(s):  
S. Titus ◽  
K.J. Szymanska ◽  
B. Musul ◽  
V. Turan ◽  
E. Taylan ◽  
...  
Keyword(s):  
Dna Damage ◽  
Single Cell ◽  
Rna Sequencing ◽  
Ovarian Reserve ◽  
Xenograft Model ◽  
Primordial Follicle ◽  
Human Ovary ◽  
Primordial Follicles ◽  
Growth Initiation

AbstractGonadotoxic chemotherapeutics, such as cyclophosphamide, cause early menopause and infertility in women. Earlier histological studies showed ovarian reserve depletion via severe DNA damage and apoptosis, but others suggested activation of PI3K/PTEN/Akt pathway and follicle ‘burn-out’ as a cause. Using a human ovarian xenograft model, we performed single-cell RNA-sequencing on laser-captured individual primordial follicle oocytes 12h after a single cyclophosphamide injection to determine the mechanisms of acute follicle loss after gonadotoxic chemotherapy. RNA-sequencing showed 190 differentially expressed genes between the cyclophosphamide- and vehicle-exposed oocytes. Ingenuity Pathway Analysis predicted a significant decrease in the expression of anti-apoptotic pro-Akt PECAM1 (p=2.13E-09), IKBKE (p=0.0001), and ANGPT1 (p=0.003), and reduced activation of PI3K/PTEN/Akt after cyclophosphamide. The qRT-PCR and immunostaining confirmed that in primordial follicle oocytes, cyclophosphamide did not change the expressions of Akt (p=0.9), rpS6 (p=0.3), Foxo3a (p=0.12) and anti-apoptotic Bcl2 (p=0.17), nor affect their phosphorylation status. There was significantly increased DNA damage by γH2AX (p=0.0002) and apoptosis by active-caspase-3 (p=0.0001) staining in the primordial follicles and no change in the growing follicles 12h after chemotherapy. These data suggest that the mechanism of acute follicle loss by cyclophosphamide is via apoptosis, rather than growth activation of primordial follicle oocytes in the human ovary.One Sentence SummarySingle-cell transcriptomic interrogation of primordial follicles in human ovarian xenografts reveals that chemotherapy causes acute ovarian reserve depletion by inducing a pro-apoptotic state rather than activating pathways that result in follicle growth initiation.

Determining androgen inactivation status in prostate cancer by [18F] DHT PET.

2019 ◽  
Vol 37 (7_suppl) ◽  
pp. 191-191
Author(s):  
Ziqi Zhu ◽  
Yoon-Mi Chung ◽  
Olga Sergeeva ◽  
Vladimir Kepe ◽  
Michael Berk ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Retention Rate ◽  
Xenograft Model ◽  
Treatment Resistance ◽  
Fold Increase ◽  
Standard Uptake Value ◽  
Retention Rates ◽  
Castration Resistant Prostate Cancer ◽  
Pet Ct

191 Background: Castration-resistant prostate cancer occurs in part due to increased tumor tissue testosterone (T) and dihydrotestosterone (DHT) that sustain tumor growth. T and DHT are converted to inactive T- and DHT-glucuronide (T/DHT-G) by uridine 5'-diphospho-glucuronosyltransferase family genes (UGT2B15 and UGT2B17) in glucuronidation-competent cells and excreted, but not in glucuronidation-deficient cells. Thus, low glucuronidation activity enables prostate tumors to preserve androgens, which increases hormone treatment resistance and may be detectable by functional imaging. Methods: We knocked out (KO) UGT2B15 and 17 in LNCaP cells and tested the DHT retention rate in the cell lines by pulse-chase using [3H]DHT as a probe. Free and DHT-G retention rates were separately determined after 5 to 60 min. To increase the signal difference between control and KO cells, we screened several ATP-binding cassette transporter inhibitors to block DHT-G excretion. We performed [18F]DHT PET/CT in castrated mice having a control and a KO xenograft on contralateral flanks ( n = 3). The ratio of the standard uptake value (SUV) in control to KO xenografts in each mouse was calculated. To increase the ratio between control and KO tumors, 50µg cyclosporin A (CSA) was injected 30 min before injecting [18F]DHT. Results: After 5 minutes of chase, control cells retained twice the DHT of KO cells. In control cells, 50%-70% DHT was glucuronidated. Almost no DHT-G was detected in KO cells, and free DHT was similar to control. Of the inhibitors, only CSA increased DHT-G (but not free DHT) in control cells, resulting in a 3-4-fold increase in overall signal. In vivo PET/CT showed control xenografts had higher peak SUV but also a higher elution rate. CSA increased the SUV ratio by 1.5-2. Conclusions: We developed a PET/CT modality to detect androgen inactivation in a prostate cancer xenograft model. Androgen-glucuronidation-proficient tumors give off a stronger signal that is increased by ATP transporter inhibition. Our method can provide a noninvasive means of determining androgen metabolism status and therefore could possibly predict effectiveness of potential therapies in a subgroup of tumors predisposed to androgen deprivation resistance.

Sign in / Sign up

Export Citation Format

Share Document