scholarly journals GZ17-6.02 and Pemetrexed Interact to Kill Osimertinib-Resistant NSCLC Cells That Express Mutant ERBB1 Proteins

2021 ◽  
Vol 11 ◽  
Author(s):  
Laurence Booth ◽  
Cameron West ◽  
Robert P. Moore ◽  
Daniel Von Hoff ◽  
Paul Dent
Keyword(s):  
Drug Combination ◽  
Molecular Mechanisms ◽  
Dominant Negative ◽  
The Novel ◽  
Ras Proteins ◽  
Caspase 9 ◽  
Autophagosome Formation ◽  
Over Expression ◽  
Mtor Protein ◽  
Synthase Inhibitor

We determined the molecular mechanisms by which the novel therapeutic GZ17-6.02 killed non-small cell lung cancer (NSCLC) cells. Erlotinib, afatinib, and osimertinib interacted with GZ17-6.02 to kill NSCLC cells expressing mutant EGFR proteins. GZ17-6.02 did not interact with any EGFR inhibitor to kill osimertinib-resistant cells. GZ17-6.02 interacted with the thymidylate synthase inhibitor pemetrexed to kill NSCLC cells expressing mutant ERBB1 proteins or mutant RAS proteins or cells that were resistant to EGFR inhibitors. The drugs interacted to activate ATM, the AMPK, and ULK1 and inactivate mTORC1, mTORC2, ERK1/2, AKT, eIF2α; and c-SRC. Knockdown of ATM or AMPKα1 prevented ULK1 activation. The drugs interacted to cause autophagosome formation followed by flux, which was significantly reduced by knockdown of ATM, AMPKα1, and eIF2α, or by expression of an activated mTOR protein. Knockdown of Beclin1, ATG5, or [BAX + BAK] partially though significantly reduced drug combination lethality as did expression of activated mTOR/AKT/MEK1 or over-expression of BCL-XL. Expression of dominant negative caspase 9 weakly reduced killing. The drug combination reduced the expression of HDAC2 and HDAC3, which correlated with lower PD-L1, IDO1, and ODC levels and increased MHCA expression. Collectively, our data support consideration of combining GZ17-6.02 and pemetrexed in osimertinib-resistant NSCLC.

The Anti-Proliferative Activity of Anisosciadone: A New Guaiane Sesquiterpene from Anisosciadium lanatum

2019 ◽  
Vol 19 (9) ◽  
pp. 1114-1119 ◽  
Author(s):  
Ahmed A. Mahmoud ◽  
Wael M. El-Sayed
Keyword(s):  
Anticancer Agents ◽  
Antiproliferative Activity ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Chemical Constituents ◽  
Spectroscopic Techniques ◽  
Significant Activity ◽  
Caspase 9 ◽  
P53 Expression ◽  
Expression And Activity

Background: The increase in cancer rate and the development of resistant tumors require a continuous search for new anticancer agents. Aims: This study aimed to analyze and identify the chemical constituents of Anisosciadium lanatum, and to investigate the antiproliferative activity of the identified constituents against various human cell lines (HepG2, MCF7, HT29, A549, and PC3) along with the possible molecular mechanisms involved. Methods: The structure of the isolated compounds was determined by spectroscopic techniques including HRFABMS, GC-MS, IR, and 400 MHz 1D and 2D NMR analyses (1H, 13C NMR, DEPT, 1H-1H COSY, HMQC, HMBC and NOESY). The antiproliferative activity and IC50 value of the isolated compounds were measured and compared to doxorubicin. Results: A new guaiane sesquiterpene containing a rare epoxide structural element, 10β,11β−epoxy−1α,4β,5β,7αΗ- guaiane-9-one, anisosciadone (1), and stigmasterol (2) have been isolated from the plant. Anisosciadone (1) showed a significant antiproliferative activity against liver, colon, and lung cells only, while stigmasterol (2) had a significant activity against liver, colon, and breast cells. Both 1 and 2 caused no cytotoxicity to normal fibroblasts. Anisosciadone elevated the expression and activity of Caspase 3 as well as p53 expression without affecting Caspase 9 in HepG2 cells. It also caused ~ 50% downregulation in cdk1 expression. Conclusion: Taken together, anisosciadone was specific in action against cancer cells and induced apoptosis in liver cells. It also has a unique feature by elevating the expression and activity of Caspase 3 without affecting the initiator Caspase 9. Therefore, anisosciadone deserves more investigation as a targeted therapy for cancer.

scholarly journals Targeting fibroblast growth factor receptors to combat aggressive ependymoma

2021 ◽  
Author(s):  
Daniela Lötsch ◽  
Dominik Kirchhofer ◽  
Bernhard Englinger ◽  
Li Jiang ◽  
Konstantin Okonechnikov ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Molecular Mechanisms ◽  
Radial Glia ◽  
Growth Factor Receptors ◽  
Dominant Negative ◽  
Mrna Levels ◽  
Fibroblast Growth ◽  
Cell Models ◽  
Fibroblast Growth Factor Receptors

AbstractEpendymomas (EPN) are central nervous system tumors comprising both aggressive and more benign molecular subtypes. However, therapy of the high-risk subtypes posterior fossa group A (PF-A) and supratentorial RELA-fusion positive (ST-RELA) is limited to gross total resection and radiotherapy, as effective systemic treatment concepts are still lacking. We have recently described fibroblast growth factor receptors 1 and 3 (FGFR1/FGFR3) as oncogenic drivers of EPN. However, the underlying molecular mechanisms and their potential as therapeutic targets have not yet been investigated in detail. Making use of transcriptomic data across 467 EPN tissues, we found that FGFR1 and FGFR3 were both widely expressed across all molecular groups. FGFR3 mRNA levels were enriched in ST-RELA showing the highest expression among EPN as well as other brain tumors. We further identified high expression levels of fibroblast growth factor 1 and 2 (FGF1, FGF2) across all EPN subtypes while FGF9 was elevated in ST-EPN. Interrogation of our EPN single-cell RNA-sequencing data revealed that FGFR3 was further enriched in cycling and progenitor-like cell populations. Corroboratively, we found FGFR3 to be predominantly expressed in radial glia cells in both mouse embryonal and human brain datasets. Moreover, we detected alternative splicing of the FGFR1/3-IIIc variant, which is known to enhance ligand affinity and FGFR signaling. Dominant-negative interruption of FGFR1/3 activation in PF-A and ST-RELA cell models demonstrated inhibition of key oncogenic pathways leading to reduced cell growth and stem cell characteristics. To explore the feasibility of therapeutically targeting FGFR, we tested a panel of FGFR inhibitors in 12 patient-derived EPN cell models revealing sensitivity in the low-micromolar to nano-molar range. Finally, we gain the first clinical evidence for the activity of the FGFR inhibitor nintedanib in the treatment of a patient with recurrent ST-RELA. Together, these preclinical and clinical data suggest FGFR inhibition as a novel and feasible approach to combat aggressive EPN.

scholarly journals High-density transposon libraries utilising outward-oriented promoters identify mechanisms of action and resistance to antimicrobials

2020 ◽  
Vol 367 (22) ◽  
Author(s):  
Chris Coward ◽  
Gopujara Dharmalingham ◽  
Omar Abdulle ◽  
Tim Avis ◽  
Stephan Beisken ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Pathogenic Bacteria ◽  
Selective Advantage ◽  
Mechanisms Of Action ◽  
Over Expression ◽  
E Coli ◽  
Synthase Inhibitor ◽  
Established Technique ◽  
Bacterial Transposon

ABSTRACT The use of bacterial transposon mutant libraries in phenotypic screens is a well-established technique for determining which genes are essential or advantageous for growth in conditions of interest. Standard, inactivating, transposon libraries cannot give direct information about genes whose over-expression gives a selective advantage. We report the development of a system wherein outward-oriented promoters are included in mini-transposons, generation of transposon mutant libraries in Escherichia coli and Pseudomonas aeruginosa and their use to probe genes important for growth under selection with the antimicrobial fosfomycin, and a recently-developed leucyl-tRNA synthase inhibitor. In addition to the identification of known mechanisms of action and resistance, we identify the carbon–phosphorous lyase complex as a potential resistance liability for fosfomycin in E. coli and P. aeruginosa. The use of this technology can facilitate the development of novel mechanism-of-action antimicrobials that are urgently required to combat the increasing threat worldwide from antimicrobial-resistant pathogenic bacteria.

scholarly journals Placental Vacuolar ATPase Function Is a Key Link between Multiple Causes of Preeclampsia

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Dongxin Zhang ◽  
Duyun Ye ◽  
Hongxiang Chen
Keyword(s):  
Molecular Mechanisms ◽  
Renin Angiotensin System ◽  
Vacuolar Atpase ◽  
Therapeutic Interventions ◽  
The Novel ◽  
Lipoxin A4 ◽  
Angiotensin System ◽  
Dihydroxyvitamin D ◽  
System 1 ◽  
Multiple Causes

Preeclampsia, a relatively common pregnancy disorder, is one of the major causes of maternal and fetal morbidity and mortality. Despite numerous research, the etiology of this syndrome remains not well understood as the pathogenesis of preeclampsia is complex, involving interaction between genetic, immunologic, and environmental factors. Preeclampsia, originating in placenta abnormalities, is induced by the circulating factors derived from the abnormal placenta. Recent work has identified various molecular mechanisms related to placenta development, including renin-angiotensin system, 1, 25-dihydroxyvitamin D, and lipoxin A4. Interestingly, advances suggest that vacuolar ATPase, a key molecule in placentation, is closely associated with them. Therefore, this intriguing molecule may represent an important link between various causes of preeclampsia. Here, we review that vacuolar ATPase works as a key link between multiple causes of preeclampsia and discuss the potential molecular mechanisms. The novel findings outlined in this review may provide promising explanations for the causation of preeclampsia and a rationale for future therapeutic interventions for this condition.

Formation, translocation and resolution of Holliday junctions during homologous genetic recombination

1995 ◽  
Vol 347 (1319) ◽  
pp. 21-25 ◽  
Keyword(s):  
Molecular Mechanisms ◽  
Genetic Recombination ◽  
Holliday Junctions ◽  
The Novel ◽  
E Coli ◽  
The Past ◽  
Endonucleolytic Cleavage ◽  
Insight Into ◽  
Made In

Over the past three or four years, great strides have been made in our understanding of the proteins involved in recombination and the mechanisms by which recombinant molecules are formed. This review summarizes our current understanding of the process by focusing on recent studies of proteins involved in the later steps of recombination in bacteria. In particular, biochemical investigation of the in vitro properties of the E. coli RuvA, RuvB and RuvC proteins have provided our first insight into the novel molecular mechanisms by which Holliday junctions are moved along DNA and then resolved by endonucleolytic cleavage.

scholarly journals Role of glucocorticoid receptor and CCAAT/enhancer-binding protein α in the feed-forward induction of 11β-hydroxysteroid dehydrogenase type 1 expression by cortisol in human amnion fibroblasts

2007 ◽  
Vol 195 (2) ◽  
pp. 241-253 ◽  
Author(s):  
Zhen Yang ◽  
Chunming Guo ◽  
Ping Zhu ◽  
Wenjiao Li ◽  
Leslie Myatt ◽  
...  
Keyword(s):  
Glucocorticoid Receptor ◽  
Mrna Expression ◽  
Promoter Region ◽  
Molecular Mechanisms ◽  
Hydroxysteroid Dehydrogenase ◽  
Dominant Negative ◽  
Forward Induction ◽  
Human Amnion ◽  
Feed Forward

The amount of cortisol available to its receptors is increased by the pre-receptor enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) which converts cortisone to cortisol. We examined the molecular mechanisms of the feedback effect of cortisol on 11β-HSD1 mRNA expression in human amnion fibroblasts. Our data showed that cortisol-induced 11β-HSD1 mRNA expression dose dependently in amnion fibroblasts, which could be completely blocked both by the mRNA transcription inhibitor 5,6-dichlorobenzimidazole riboside and by the glucocorticoid receptor (GR) antagonist RU486, and partially blocked by global inhibition of CCAAT/enhancer-binding proteins (C/EBPs) with transfection of C/EBP-specific dominant-negative expression CMV500 plasmid (AC/EBP) into the cells. Likewise, the induction of the promoter activity by cortisol could also be completely blocked by RU486 and partially by AC/EBP transfection. Progressive 5′ deletion of the 11β-HSD1promoter located the region responsible for cortisol’s induction within −204 bp upstream to the transcription start site. Specific nucleotide mutations of the putative glucocorticoid responsive element or CCAAT in this promoter region attenuated the induction by cortisol. Moreover, chromatin immunoprecipitation assay and electrophoretic mobility shift assay showed that GR and C/EBPα but not C/EBPβ could bind this promoter region upon cortisol stimulation of amnion fibroblasts. In conclusion, we demonstrated that GR and C/EBPα were involved in cortisol-induced 11β-HSD1 mRNA expression via binding to 11β-HSD1 promoter in amnion fibroblasts, which may cast a feed-forward production of cortisol in the fetal membranes at the end of gestation.

scholarly journals Identification of Differentially Expressed Genes in Porcine Ovaries at Proestrus and Estrus Stages Using RNA-Seq Technique

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Songbai Yang ◽  
Xiaolong Zhou ◽  
Yue Pei ◽  
Han Wang ◽  
Ke He ◽  
...  
Keyword(s):  
Differentially Expressed Genes ◽  
Molecular Mechanisms ◽  
Expression Patterns ◽  
Hormone Secretion ◽  
Differentially Expressed ◽  
Receptor Interaction ◽  
The Novel ◽  
Kegg Pathways ◽  
Go Enrichment ◽  
Single Organism

Estrus is an important factor for the fecundity of sows, and it is involved in ovulation and hormone secretion in ovaries. To better understand the molecular mechanisms of porcine estrus, the expression patterns of ovarian mRNA at proestrus and estrus stages were analyzed using RNA sequencing technology. A total of 2,167 differentially expressed genes (DEGs) were identified (P≤0.05, log2  Ratio≥1), of which 784 were upregulated and 1,383 were downregulated in the estrus compared with the proestrus group. Gene Ontology (GO) enrichment indicated that these DEGs were mainly involved in the cellular process, single-organism process, cell and cell part, and binding and metabolic process. In addition, a pathway analysis showed that these DEGs were significantly enriched in 33 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, including cell adhesion molecules, ECM-receptor interaction, and cytokine-cytokine receptor interaction. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) confirmed the differential expression of 10 selected DEGs. Many of the novel candidate genes identified in this study will be valuable for understanding the molecular mechanisms of the sow estrous cycle.

scholarly journals Suppressor Mutations Bypass the Requirement of fluG for Asexual Sporulation and Sterigmatocystin Production in Aspergillus nidulans

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1083-1093
Author(s):  
Jeong-Ah Seo ◽  
Yajun Guan ◽  
Jae-Hyuk Yu
Keyword(s):  
Aspergillus Nidulans ◽  
Molecular Mechanisms ◽  
Dominant Negative ◽  
Wild Type ◽  
Dominant Mutation ◽  
Site Mutation ◽  
Asexual Sporulation ◽  
Dominant Negative Mutation ◽  
Suppressor Mutations ◽  
Early Developmental

Abstract Asexual sporulation (conidiation) in the filamentous fungus Aspergillus nidulans requires the early developmental activator fluG. Loss of fluG results in the blockage of both conidiation and production of the mycotoxin sterigmatocystin (ST). To investigate molecular mechanisms of fluG-dependent developmental activation, 40 suppressors of fluG (SFGs) that conidiate without fluG have been isolated and characterized. Genetic analyses showed that an individual suppression is caused by a single second-site mutation, and that all sfg mutations but one are recessive. Pairwise meiotic crosses grouped mutations to four loci, 31 of them to sfgA, 6 of them to sfgB, and 1 each to sfgC and sfgD, respectively. The only dominant mutation, sfgA38, also mapped to the sfgA locus, suggesting a dominant negative mutation. Thirteen sfgA and 1 sfgC mutants elaborated conidiophores in liquid submerged culture, indicating that loss of either of these gene functions not only bypasses fluG function but also results in hyperactive conidiation. While sfg mutants show varying levels of restored conidiation, all recovered the ability to produce ST at near wild-type levels. The fact that at least four loci are defined by recessive sfg mutations indicates that multiple genes negatively regulate conidiation downstream of fluG and that the activity of fluG is required to remove such repressive effects.

WZsGreen/+: a new green fluorescent protein knock-in mouse model for the study of KIT-expressing cells in gut and cerebellum

2005 ◽  
Vol 22 (3) ◽  
pp. 412-421 ◽  
Author(s):  
Mira Wouters ◽  
Karine Smans ◽  
Jean-Marie Vanderwinden
Keyword(s):  
Small Intestine ◽  
Green Fluorescent Protein ◽  
Gastrointestinal Tract ◽  
Molecular Mechanisms ◽  
Fluorescent Protein ◽  
Molecular Layer ◽  
Transgenic Animals ◽  
The Novel ◽  
Suitable Alternative ◽  
Green Fluorescent

In the small intestine, interstitial cells of Cajal (ICC) surrounding the myenteric plexus generate the pacemaking slow waves that are essential for an efficient intestinal transit. The underlying molecular mechanisms of the slow wave are poorly known. KIT is currently the sole practical marker for ICC. Attempts to purify living ICC have so far largely failed, due to the loss of the KIT epitope during enzymatic dissociation. Aiming to identify and isolate living ICC, we designed a knock-in strategy to express a fluorescent tag in KIT-expressing cells by inserting the sequence of the novel green fluorescent protein ZsGreen into the first exon of the c-Kit gene, creating a null allele called WZsGreen. In the gastrointestinal tract of heterozygous WZsGreen/+ mice, tiny ZsGreen fluorescent dots were observed in all KIT-expressing ICC populations, with exception of ICC at the deep muscular plexus in small intestine. During development of the gastrointestinal tract, ZsGreen expression followed KIT expression in a spatiotemporal way. Stellate and basket KIT-expressing cells in the molecular layer of the cerebellum also exhibited ZsGreen dots, whereas no ZsGreen was detected in skin, testis, and bone marrow. ZsGreen dot-containing intestinal cells could be isolated from jejunum and maintained alive in culture for at least 3 days. ZsGreen is a suitable alternative to EGFP in transgenic animals. The novel WZsGreen/+ model reported here appears to be a promising tool for live studies of KIT-expressing cells in the gastrointestinal tract and cerebellum and for the further analysis of pacemaker mechanisms.

Nociceptin, a novel endogenous ligand for the ORL1 receptor, has potent erectile activity in the cat

1997 ◽  
Vol 273 (1) ◽  
pp. E214-E219 ◽  
Author(s):  
H. C. Champion ◽  
R. Wang ◽  
W. J. Hellstrom ◽  
P. J. Kadowitz
Keyword(s):  
Drug Combination ◽  
Nitric Oxide Donor ◽  
The Novel ◽  
Orphanin Fq ◽  
Endogenous Ligand ◽  
Intracavernosal Injection ◽  
Orl1 Receptor ◽  
Arterial Blood ◽  
Intracavernosal Injections ◽  
G Protein Coupled

The heptadecapeptide nociceptin, also known as orphanin FQ, is a newly discovered endogenous ligand for the opioid-like G protein-coupled receptor ORL1. The present study was undertaken to investigate the effects of intracavernosal injections of nociceptin on penile erection in anesthetized cats. Responses to nociception were compared with erectile responses elicited by intracavernosal injection of vasoactive intestinal polypeptide (VIP), adrenomedullin (ADM), the novel nitric oxide donor diethylaminenitric oxide complex sodium (DEA/NO), and the control triple-drug combination (papaverine, phentolamine, and prostaglandin E1). The order of potency was VIP > ADM > nociceptin > DEA/NO. Intracavernosal injections of nociceptin in doses of 0.3-30 nmol elicited dose-related increases in cavernosal pressure and penile length that were comparable to those induced by the triple-drug combination, which is used in the treatment of erectile dysfunction. The response to nociceptin was rapid in onset, and the duration of the peak pressure increase and total response was significantly shorter than the response to the control triple-drug combination but longer in duration than responses to VIP and ADM. Intracavernosal injection of the triple-drug combination resulted in a greater decrease in mean systemic arterial blood pressure than did nociceptin. These data demonstrate that intracavernosal injection of this novel endogenous ligand for the ORL1 receptor induces a potent and relatively long-lasting erectile response in the cat.

Sign in / Sign up

Export Citation Format

Share Document