scholarly journals MODL-16. ABEMACICLIB, A SELECTIVE CDK4/6 INHIBITOR, RESTRICTS GROWTH OF PEDIATRIC GLIAL-LINEAGE TUMORS IN VITRO AND IN VIVO

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii414-iii414
Author(s):  
Muh-Lii Liang ◽  
Tsung-Han Hsieh ◽  
Tai-Tong Wong

Abstract BACKGROUND Glial-lineage tumors constitute a heterogeneous group of neoplasms, comprising gliomas, oligodendrogliomas, and ependymomas, which account for 40%–50% of all pediatric central nervous system tumors. Advances in modern neuro-oncological therapeutics are aimed at improving neoadjuvant chemotherapy and deferring radiotherapy because radiation exposure may cause long-term side effects on the developing brain in young children. Despite aggressive treatment, more than half the high-grade gliomas (pHGGs) and one-third of ependymomas exhibit recurrence within 2 years of initial treatment. METHODS By using integrated bioinformatics and through experimental validation, we found that at least one gene among CCND1, CDK4, and CDK6 was overexpressed in pHGGs and ependymomas. RESULTS The use of abemaciclib, a highly selective CDK4/6 inhibitor, effectively inhibited cell proliferation and reduced the expression of cell cycle–related and DNA repair–related gene expression, which was determined through RNA-seq analysis. The efficiency of abemaciclib was validated in vitro in pHGGs and ependymoma cells and in vivo by using subcutaneously implanted ependymoma cells from patient-derived xenograft (PDX) in mouse models. Abemaciclib demonstrated the suppression of RB phosphorylation, downstream target genes of E2F, G2M checkpoint, and DNA repair, resulting in tumor suppression. CONCLUSION Abemaciclib showed encouraging results in preclinical pediatric glial-lineage tumors models and represented a potential therapeutic strategy for treating challenging tumors in children.

Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3597
Author(s):  
Muh-Lii Liang ◽  
Chun-Han Chen ◽  
Yun-Ru Liu ◽  
Man-Hsu Huang ◽  
Yu-Chen Lin ◽  
...  

Pediatric ependymomas are a type of malignant brain tumor that occurs in children. The overall 10-year survival rate has been reported as being 45–75%. Maximal safe surgical resection combined with adjuvant chemoradiation therapy is associated with the highest overall and progression-free survival rates. Despite aggressive treatment, one-third of ependymomas exhibit recurrence within 2 years of initial treatment. Therefore, this study aimed to find new agents to overcome chemoresistance and defer radiotherapy treatment since, in addition, radiation exposure may cause long-term side effects in the developing brains of young children. By using integrated bioinformatics and through experimental validation, we found that at least one of the genes CCND1 and CDK4 is overexpressed in ependymomas. The use of abemaciclib, a highly selective CDK4/6 inhibitor, effectively inhibited cell proliferation and reduced the expression of cell-cycle-related and DNA-repair-related gene expression via the suppression of RB phosphorylation, which was determined through RNA-seq and Western blot analyses. Furthermore, abemaciclib effectively induced cell death in vitro. The efficiency of abemaciclib was validated in vivo using subcutaneously implanted ependymoma tissues from patient-derived xenografts (PDXs) in mouse models. Treatment with abemaciclib showed encouraging results in preclinical pediatric ependymoma models and represents a potential therapeutic strategy for treating challenging tumors in children.


Author(s):  
Evert Njomen ◽  
Theresa A. Lansdell ◽  
Allison Vanecek ◽  
Vanessa Benham ◽  
Matt P. Bernard ◽  
...  

SUMMARYEnhancing proteasome activity is a potential new therapeutic strategy to prevent the accumulation of aberrant high levels of protein that drive the pathogenesis of many diseases. Herein, we examine the use of small molecules to activate the 20S proteasome to reduce aberrant signaling by the undruggable oncoprotein c-MYC, to treat c-MYC driven oncogenesis. Overexpression of c-MYC is found in more than 50% of all human cancer but remains undruggable because of its highly dynamic intrinsically disordered 3-D conformation, which renders traditional therapeutic strategies largely ineffective. We demonstrate herein that small molecule activation of the 20S proteasome targets dysregulated intrinsically disordered proteins (IDPs), including c-MYC, and reduces cancer growth in vitro and in vivo models of multiple myeloma, and is even effective in bortezomib resistant cells and unresponsive patient samples. Genomic analysis of various cancer pathways showed that proteasome activation results in downregulation of many c-MYC target genes. Moreover, proteasome enhancement was well tolerated in mice and dogs. These data support the therapeutic potential of 20S proteasome activation in targeting IDP-driven proteotoxic disorders, including cancer, and demonstrate that this new therapeutic strategy is well tolerated in vivo.


2021 ◽  
Author(s):  
Yanhui Hao ◽  
Wenchao Li ◽  
Hui Wang ◽  
Jing Zhang ◽  
Haoyu Wang ◽  
...  

Abstract Background With the development of science and technology, microwaves are being widely used. More and more attention has been paid to the potential health hazards of microwave exposure. The regulation of miR-30a-5p (miR-30a) on autophagy is involved in the pathophysiological process of many diseases. Our previous study found that 30 mW/cm2 microwave radiation could reduce miR-30a expression and activate neuronal autophagy in rat hippocampus. However, the roles played by miR-30a in microwave-induced neuronal autophagy and related mechanisms remain largely unexplored. Results In the present study, we established neuronal damage models by exposing rat hippocampal neurons and rat adrenal pheochromocytoma (PC12) cell-derived neuron-like cells to 30 mW/cm2 microwave, which resulted in miR-30a downregulation and autophagy activation in vivo and in vitro. Bioinformatics analysis was conducted, and Beclin1, Prkaa2, Irs1, Pik3r2, Rras2, Ddit4, Gabarapl2 and autophagy-related gene 12 (Atg12) were identified as potential downstream target genes of miR-30a involved in regulating autophagy. Based on our previous findings that microwave radiation can cause a neuronal energy metabolism disorder, Prkaa2, encoding adenosine 5’-monophosphate-activated protein kinase α2 (AMPKα2, an important catalytic subunit of energy sensor AMPK), was selected for further analysis. Dual-luciferase reporter assay results showed that Prkaa2 is a downstream target gene of miR-30a. Microwave radiation increased the expression and phosphorylation (Thr172) of AMPKα both in vivo and in vitro. Moreover, the transduction of cells with miR-30a mimics suppressed AMPKα2 expression, inhibited AMPKα (Thr172) phosphorylation and reduced autophagy flux in neuron-like cells. Importantly, miR-30a mimics abolished microwave-activated autophagy and inhibited microwave-induced AMPKα (Thr172) phosphorylation. Conclusions AMPKα2 was a newly founded downstream gene of miR-30a involved in autophagy regulation, and miR-30a downregulation after microwave radiation could promote neuronal autophagy by increasing AMPKα2 expression and activating AMPK signaling.


Development ◽  
2001 ◽  
Vol 128 (18) ◽  
pp. 3405-3413 ◽  
Author(s):  
Adi Inbal ◽  
Naomi Halachmi ◽  
Charna Dibner ◽  
Dale Frank ◽  
Adi Salzberg

Homothorax (HTH) is a homeobox-containing protein, which plays multiple roles in the development of the embryo and the adult fly. HTH binds to the homeotic cofactor Extradenticle (EXD) and translocates it to the nucleus. Its function within the nucleus is less clear. It was shown, mainly by in vitro studies, that HTH can bind DNA as a part of ternary HTH/EXD/HOX complexes, but little is known about the transcription regulating function of HTH-containing complexes in the context of the developing fly. Here we present genetic evidence, from in vivo studies, for the transcriptional-activating function of HTH. The HTH protein was forced to act as a transcriptional repressor by fusing it to the Engrailed (EN) repression domain, or as a transcriptional activator, by fusing it to the VP16 activation domain, without perturbing its ability to translocate EXD to the nucleus. Expression of the repressing form of HTH in otherwise wild-type imaginal discs phenocopied hth loss of function. Thus, the repressing form was working as an antimorph, suggesting that normally HTH is required to activate the transcription of downstream target genes. This conclusion was further supported by the observation that the activating form of HTH caused typical hth gain-of-function phenotypes and could rescue hth loss-of-function phenotypes. Similar results were obtained with XMeis3, the Xenopus homologue of HTH, extending the known functional similarity between the two proteins. Competition experiments demonstrated that the repressing forms of HTH or XMeis3 worked as true antimorphs competing with the transcriptional activity of the native form of HTH. We also describe the phenotypic consequences of HTH antimorph activity in derivatives of the wing, labial and genital discs. Some of the described phenotypes, for example, a proboscis-to-leg transformation, were not previously associated with alterations in HTH activity. Observing the ability of HTH antimorphs to interfere with different developmental pathways may direct us to new targets of HTH. The HTH antimorph described in this work presents a new means by which the transcriptional activity of the endogenous HTH protein can be blocked in an inducible fashion in any desired cells or tissues without interfering with nuclear localization of EXD.


2003 ◽  
Vol 17 (5) ◽  
pp. 860-869 ◽  
Author(s):  
Michael J. Coghlan ◽  
Peer B. Jacobson ◽  
Ben Lane ◽  
Masaki Nakane ◽  
Chun Wei Lin ◽  
...  

Abstract Glucocorticoids (GCs) are commonly used to treat inflammatory disease; unfortunately, the long-term use of these steroids leads to a large number of debilitating side effects. The antiinflammatory effects of GCs are a result of GC receptor (GR)-mediated inhibition of expression of proinflammatory genes as well as GR-mediated activation of antiinflammatory genes. Similarly, side effects are most likely due to both activated and repressed GR target genes in affected tissues. An as yet unachieved pharmaceutical goal is the development of a compound capable of separating detrimental side effects from antiinflammatory activity. We describe the discovery and characterization of AL-438, a GR ligand that exhibits an altered gene regulation profile, able to repress and activate only a subset of the genes normally regulated by GCs. When tested in vivo, AL-438 retains full antiinflammatory efficacy and potency comparable to steroids but its negative effects on bone metabolism and glucose control are reduced at equivalently antiinflammatory doses. The mechanism underlying this selective in vitro and in vivo activity may be the result of differential cofactor recruitment in response to ligand. AL-438 reduces the interaction between GR and peroxisomal proliferator-activated receptor γ coactivator-1, a cofactor critical for steroid-mediated glucose up-regulation, while maintaining normal interactions with GR-interacting protein 1. This compound serves as a prototype for a unique, nonsteroidal alternative to conventional GCs in treating inflammatory disease.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A802-A802
Author(s):  
Neerupma Silswal ◽  
Joe Bean ◽  
Herschel Gupta ◽  
Fatma Talib ◽  
Suban Burale ◽  
...  

Abstract Twelve percent of pregnant women receive glucocorticoids (sGCs) to reduce the risks to reduce morbidity and mortality associated with preterm birth in infants. The two most commonly administered sGC are Dexamethasone (Dex) and Betamethasone (Beta) and they serve to decrease the severity of respiratory distress, intraventricular hemorrhage and necrotizing enterocolitis. However, repeated administration of sGC has been shown to be associated with adverse neurological outcome and depends on the type of sGCs used, dose, timing of sGCs administration and sex. We have previously shown that prenatal exposure to Dex in a murine model lead to sex specific changes in the transcription response and in the biological function of neural stem cells and to long-term changes in brain architecture and behavior. Beta is the predominant sGC used prenatally in the United States, therefore these studies investigated the cellular and molecular responses to beta exposure on the neural stem cells in-vitro and anatomical organization of the brain in-vivo. Murine NSCs were isolated from the E14.5 cerebral cortex and exposed to 10-7 M Dex, 10-7 M Beta, or Vehicle for 4 or 24 hours and the immediate and long-term impact on transcription, proliferation and neuronal, glial and oligodendrocyte differentiation examined. Affymetrix genome transcriptional analyses reveal sex specific responses to Dex vs Beta in 4 hours. In females 682 genes were differentially regulated by Dex compared to 576 by Beta. In contrast, 875 were altered by Dex and 576 by Beta in males (Fold change > +/- 1.5, P< 0.05). Select target genes were independently validated by QPCR. Ingenuity Pathway Analysis was used to identify unique and overlapping pathways that were altered by Dex vs Beta. In males, Dex uniquely altered 34 pathways including, Thyroid Hormone Metabolism, ERK5 Signaling and Opioid Signaling while Bata altered 33 pathways including, Phagasome formation, IL-7 Signaling and JAK STAT signaling. In Females, Dex altered 45 pathways including Calcium Signaling, Serotonin Receptor Signaling and Xenobiotic Signaling, while Beta altered 46 pathways including, FXR/RXR Activation, Tec Kinase Signaling and D-myo-Inositol-5-Phosphate Metabolism. Another 35 pathways were altered by both Dex and Beta but they showed differences in genes activated or repressed. Dex and Beta, both significantly altered genes involved in proliferation and differentiation therefore the biological response of NSC to sGCs stimulation in vitro and the long term consequences of sGC exposure in-vivo was compared. Distinct differences in cell proliferation, glial and oligodendrocyte differentiation were observed. These results reveal gene targets, cellular pathways and processes that are differentially altered by prenatal Dex vs Beta exposure. Our finds may provide insights into the sex specific neurological outcomes observed in children exposed to sGCs in-utero.


2020 ◽  
Author(s):  
Yue Chang ◽  
Min Hao ◽  
Ru Jia ◽  
Yihui Zhao ◽  
Yixuan Cai ◽  
...  

Abstract Background: Endometrial cancer is an invasive gynecological cancer prevalent in the world. The pathogenesis of endometrial cancer is related to multiple levels of regulation, referring to oestrogen, tumor-suppressor gene (e.g. PTEN ) or microRNAs (e.g. miR-23a and miR-29b). Metapristone is a hormone-related drug, which is widely used in clinical treatment of endometrial cancer. However, the underlying regulatory mechanism of metapristone on endometrial cancer is still unclear, especially the regulatory effect on microRNAs. The aim of this study is to investigate the specific molecular mechanism of metapristone regulating microRNAs in the treatment of endometrial cancer. Methods: RL95-2 cells and Ishikawa cells were used as the endometrial cancer models. MiR-492 or si-miR-492 was transfected into RL95-2 cells and Ishikawa cells to explore the role of miR-492 in endometrial cancer. The cell cancer model and mice cancer model were used to confirm the function and mechanism of metapristone affected on endometrial cancer in vitro and in vivo . Mechanically, cell proliferation was monitored using the MTT assay, cell colony formation assay and EdU assay. Luciferase reporter assay was used to identify the downstream target gene of miR492. The protein expression and RNA expression were respectively measured by western blot and qRT-PCR for cell signaling pathway research, subsequently, were verified in the mice tumor model via immunohistochemistry. Results: Metapristone as a kind of hormone-related drug significantly inhibited the endometrial cancer cell growth through regulating cell apoptosis-related gene expression. Mechanically, miR-492 and its target genes Klf5 and Nrf1 were highly expressed in the endometrial cancer cell lines, which promoted cell proliferation and inhibited cell apoptosis. Metapristone decreased the expression of miR-492 and its target genes Klf5 and Nrf1 , leading to endometrial cancer cell growth inhibition in vitro and in vivo . Conclusion: Metapristone inhibited the endometrial cancer cell growth through regulating the cell apoptosis-related signaling pathway and decreasing the expression of miR-492 and its downstream target genes ( Klf5 and Nrf1 ), which provided the theoretical basis in clinical treatment of endometrial cancer.


2006 ◽  
Vol 91 (9) ◽  
pp. 3584-3591 ◽  
Author(s):  
Frank Weber ◽  
Rosemary E. Teresi ◽  
Christoph E. Broelsch ◽  
Andrea Frilling ◽  
Charis Eng

Abstract Context: Although the pathogenesis of follicular thyroid carcinoma (FTC) and its relation to follicular adenoma (FA) remains unclear, detailed understanding of FTC carcinogenesis would facilitate addressing the scientific and clinical challenges, given that there are morphological and molecular similarities between FTC and the frequently occurring FA. Micro-RNAs (miRNAs) are a new class of small, noncoding RNAs implicated in development and cancer and may lend novel clues to FTC genesis. For the latter process, a deregulated miRNA can orchestrate the aberrant expression of several hundred target genes. Objective: The objective of the study was to identify deregulated miRNAs in FTC. Design: We used two high-density expression arrays to identify miRNAs and their target genes that are differentially expressed between FTC and FA. Validation was done by quantitative RT-PCR. We further functionally characterized the effect of deregulated miRNAs in vitro using HEK293T, FTC133, and K5 cell lines. Patients: In total, 45 primary thyroid samples (23 FTC, 20 FA, four normal control thyroid) were analyzed. Results: Two specific miRNAs, miR-197 and miR-346, were significantly overexpressed in FTC. In vitro overexpression of either miRNA induced proliferation, whereas inhibition led to growth arrest. Overexpression of miR-197 and miR-346 repressed the expression of their predicted target genes in vitro and in vivo. Conclusions: Our observations show that miR-197 and miR-346 contribute to FTC carcinogenesis. Both miRNAs and their target genes might potentially provide for novel molecular markers and act as novel targets for treatment by interference, which could potentially normalize the deregulated profile of many downstream target genes.


2021 ◽  
Author(s):  
Manish Bodas ◽  
Bharathiraja Subramaniyan ◽  
Andrew R. Moore ◽  
Jordan P. Metcalf ◽  
Sarah R. Ocañas ◽  
...  

AbstractBasal cells (BC) are the resident stem/progenitor cells of the adult pseudostratified airway epithelium, whose differentiation program is orchestrated by the NOTCH signaling pathway. NOTCH3 receptor mediated signaling regulates BC to club cell differentiation; however, the downstream responses that regulate this process are largely unknown. In the present study we used an in vitro air-liquid interface model of the human pseudostratified airway epithelium to identify the NOTCH3-dependent downstream genes/pathways that regulate human BC to club cell differentiation. Activation of NOTCH3 signaling in BC via lentivirus-mediated over-expression of the active NOTCH3 intracellular domain (NICD3) promoted club cell differentiation. Bulk RNA-seq analysis of control vs NICD3-transduced cells, identified 692 NICD3 responsive genes enriched for pathways linked to airway epithelial biology and differentiation including Wnt/β-catenin Signaling. Expression of the classical NOTCH target HEYL increased in response to NOTCH3 activation and positively correlated with expression of the club cell marker SCGB1A1. Further, using single-cell RNA-seq, we report that HEYL+ cells primarily clustered with SCGB1A1+ and NOTCH3+ cells. Moreover, HEYL protein co-localized with SCGB1A1 in ALI cultures in vitro and in the human and mouse airway epithelium in vivo. siRNA-mediated knockdown of HEYL in BC led to changes in epithelial structure including altered morphology and significant reductions in transepithelial electrical resistance and expression of tight junction related genes. Finally, HEYL knockdown significantly reduced the number of SCGB1A1+ club cells, along with a corresponding increase in KRT8+ BC-intermediate cells. Overall, our data identifies NOTCH3-HEYL signaling as a key regulator of BC to club cell differentiation.


2021 ◽  
Author(s):  
Chunbao Zang ◽  
Fangfang Zhao ◽  
Dabing Huang ◽  
Lingsuo Kong ◽  
Minghua Xie ◽  
...  

Abstract Background : N 6 -methyladenosine (m 6 A) is the most abundant modification in eukaryotic messenger RNAs (mRNAs), and plays important roles in many bioprocesses. However, its functions in esophageal cancer remain elusive. Methods : Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and transcriptomic RNA sequencing (RNA-seq) were used to screen the target genes of FTO. Western blot, quantitative real-time PCR (RT-qPCR) and immunohistochemical (IHC) were used to detect FTO expression in cell lines and patient tissues. The biological functions of FTO were investigated in vitro and in vivo . RNA pull-down and RNA immunoprecipitation assays were conducted to explore the specific binding of target genes. Results : We discovered that the RNA demethylase FTO was significantly up-regulated in esophageal cancer patients. Knockdown of FTO drastically reduced esophageal cancer cells (ESCCs) proliferation, migration, invasion, and apoptosis. On the other hand, overexpression of FTO significantly promoted ESCCs growth and invasion. Moreover, we found that the m 6 A methyltransferase METTL14 negatively correlates with FTO function on esophageal cancer progression. By using transcriptome-wide m 6 A-Seq and RNA-Seq assays, we identified AKT3 is the target of FTO, which acts in concert in esophageal cancer tumorigenesis and metastasis. Moreover, loss and gain functional studies confirm that YTHDF1 mediates m 6 A-increased translation of AKT3 mRNA. Conclusion : Our results uncovered an METTL14/FTO/YTHDF1/AKT3 signaling network that regulates the esophageal cancer progression.


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