A bioanalytical investigation on the exquisitely strong in vitro potency of the EGFR–DNA targeting type II combi-molecule ZR2003 and its mitigated in vivo antitumour activity

2011 ◽  
Vol 56 (3) ◽  
pp. 592-599 ◽  
Author(s):  
Nahid Golabi ◽  
Fouad Brahimi ◽  
Ying Huang ◽  
Zakaria Rachid ◽  
Qiyu Qiu ◽  
...  
2018 ◽  
Author(s):  
Senén D. Mendoza ◽  
Joel D. Berry ◽  
Eliza S. Nieweglowska ◽  
Lina M. Leon ◽  
David A. Agard ◽  
...  

All viruses require strategies to inhibit or evade the immunity pathways of cells they infect. The viruses that infect bacteria, bacteriophages (phages), must avoid nucleic-acid targeting immune pathways such as CRISPR-Cas and restriction endonucleases to replicate efficiently1. Here, we show that a jumbo phage infecting Pseudomonas aeruginosa, phage ΦKZ, is resistant to many immune systems in vivo, including CRISPR-Cas3 (Type I-C), Cas9 (Type II-A), Cas12 (Cpf1, Type V-A), and Type I restriction-modification (R-M) systems. We propose that ΦKZ utilizes a nucleus-like shell to protect its DNA from attack. Supporting this, we demonstrate that Cas9 is able to cleave ΦKZ DNA in vitro, but not in vivo and that Cas9 is physically occluded from the shell assembled by the phage during infection. Moreover, we demonstrate that the Achilles heel for this phage is the mRNA, as translation occurs outside of the shell, rendering the phage sensitive to the RNA targeting CRISPR-Cas enzyme, Cas13a (C2c2, Type VI-A). Collectively, we propose that the nucleus-like shell assembled by jumbo phages enables potent, broad spectrum evasion of DNA-targeting nucleases.


2006 ◽  
Vol 26 (3) ◽  
pp. 965-975 ◽  
Author(s):  
Tom S. Kim ◽  
Cynthia Heinlein ◽  
Robert C. Hackman ◽  
Peter S. Nelson

ABSTRACT Tmprss2 encodes an androgen-regulated type II transmembrane serine protease (TTSP) expressed highly in normal prostate epithelium and has been implicated in prostate carcinogenesis. Although in vitro studies suggest protease-activated receptor 2 may be a substrate for TMPRSS2, the in vivo biological activities of TMPRSS2 remain unknown. We generated Tmprss2 −/− mice by disrupting the serine protease domain through homologous recombination. Compared to wild-type littermates, Tmprss2 −/− mice developed normally, survived to adulthood with no differences in protein levels of prostatic secretions, and exhibited no discernible abnormalities in organ histology or function. Loss of TMPRSS2 serine protease activity did not influence fertility, reduce survival, result in prostate hyperplasia or carcinoma, or alter prostatic luminal epithelial cell regrowth following castration and androgen replacement. Lack of an observable phenotype in Tmprss2 −/− mice was not due to transcriptional compensation by closely related Tmprss2 homologs. We conclude that the lack of a discernible phenotype in Tmprss2 −/− mice suggests functional redundancy involving one or more of the type II transmembrane serine protease family members or other serine proteases. Alternatively, TMPRSS2 may contribute a specialized but nonvital function that is apparent only in the context of stress, disease, or other systemic perturbation.


2021 ◽  
Vol 22 (16) ◽  
pp. 8372
Author(s):  
Ana María Zárate ◽  
Christian Espinosa-Bustos ◽  
Simón Guerrero ◽  
Angélica Fierro ◽  
Felipe Oyarzún-Ampuero ◽  
...  

The Smoothened (SMO) receptor is the most druggable target in the Hedgehog (HH) pathway for anticancer compounds. However, SMO antagonists such as vismodegib rapidly develop drug resistance. In this study, new SMO antagonists having the versatile purine ring as a scaffold were designed, synthesised, and biologically tested to provide an insight to their mechanism of action. Compound 4s was the most active and the best inhibitor of cell growth and selectively cytotoxic to cancer cells. 4s induced cell cycle arrest, apoptosis, a reduction in colony formation and downregulation of PTCH and GLI1 expression. BODIPY-cyclopamine displacement assays confirmed 4s is a SMO antagonist. In vivo, 4s strongly inhibited tumour relapse and metastasis of melanoma cells in mice. In vitro, 4s was more efficient than vismodegib to induce apoptosis in human cancer cells and that might be attributed to its dual ability to function as a SMO antagonist and apoptosis inducer.


2012 ◽  
Vol 32 (6) ◽  
pp. 559-566 ◽  
Author(s):  
Yan Xu ◽  
Feng Zhi ◽  
Guangming Xu ◽  
Xiaolei Tang ◽  
Sheng Lu ◽  
...  

MDR (multidrug-resistance) represents a major obstacle to successful cancer chemotherapy and is usually accomplished by overexpression of P-gp (P-glycoprotein). Much effort has been devoted to developing P-gp inhibitors to modulate MDR. However, none of the inhibitors on the market have been successful. 1416 [1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (phenoprolamine hydrochloride)] is a new VER (verapamil) analogue with a higher IC50 for blocking calcium channel currents than VER. In the present paper, we examined the inhibition effect of 1416 on P-gp both in vitro and in vivo. 1416 significantly enhanced cytotoxicity of VBL (vinblastine) in P-gp-overexpressed human multidrug-resistant K562/ADM (adriamycin) and KBV cells, but had no such effect on the parent K562 and KB cells. The MDR-modulating function of 1416 was further confirmed by increasing intracellular Rh123 (rhodanmine123) content in MDR cells. Human K562/ADM xenograft-nude mice model verified that 1416 potentiates the antitumour activity of VBL in vivo. RT-PCR (reverse transcriptase-PCR) and FACS analysis demonstrated that the expression of MDR1/P-gp was not affected by 1416 treatment. All these observations suggest that 1416 could be a promising agent for overcoming MDR in cancer chemotherapy.


2015 ◽  
Vol 42 (7) ◽  
pp. 1042-1049 ◽  
Author(s):  
Yu Zhang ◽  
Ying Zhong ◽  
Mei Hu ◽  
Nanxi Xiang ◽  
Yao Fu ◽  
...  

ESMO Open ◽  
2018 ◽  
Vol 3 (6) ◽  
pp. e000387 ◽  
Author(s):  
Chiara Tarantelli ◽  
Elena Bernasconi ◽  
Eugenio Gaudio ◽  
Luciano Cascione ◽  
Valentina Restelli ◽  
...  

BackgroundThe outcome of patients affected by mantle cell lymphoma (MCL) has improved in recent years, but there is still a need for novel treatment strategies for these patients. Human cancers, including MCL, present recurrent alterations in genes that encode transcription machinery proteins and of proteins involved in regulating chromatin structure, providing the rationale to pharmacologically target epigenetic proteins. The Bromodomain and Extra Terminal domain (BET) family proteins act as transcriptional regulators of key signalling pathways including those sustaining cell viability. Birabresib (MK-8628/OTX015) has shown antitumour activity in different preclinical models and has been the first BET inhibitor to successfully undergo early clinical trials.Materials and methodsThe activity of birabresib as a single agent and in combination, as well as its mechanism of action was studied in MCL cell lines.ResultsBirabresib showed in vitro and in vivo activities, which appeared mediated via downregulation of MYC targets, cell cycle and NFKB pathway genes and were independent of direct downregulation of CCND1. Additionally, the combination of birabresib with other targeted agents (especially pomalidomide, or inhibitors of BTK, mTOR and ATR) was beneficial in MCL cell lines.ConclusionOur data provide the rationale to evaluate birabresib in patients affected by MCL.


2000 ◽  
Vol 93 (3) ◽  
pp. 805-810 ◽  
Author(s):  
Catherine Paugam-Burtz ◽  
Serge Molliex ◽  
Bernard Lardeux ◽  
Corinne Rolland ◽  
Michel Aubier ◽  
...  

Background Pulmonary surfactant is a complex mixture of proteins and phospholipids synthetized by alveolar type II cells. Volatile anesthetics have been shown to reduce surfactant phospholipid biosynthesis by rat alveolar type II cells. Surfactant-associated protein C (SP-C) is critical for the alveolar surfactant functions. Our goal was to evaluate the effects of halothane and thiopental on SP-C messenger RNA (mRNA) expression in vitro in rat alveolar type II cells and in vivo in mechanically ventilated rats. Methods In vitro, freshly isolated alveolar type II cells were exposed to halothane during 4 h (1, 2, 4%) and 8 h (1%), and to thiopental during 4 h (10, 100 micrometer) and 8 h (100 micrometer). In vivo, rats were anesthetized with intraperitoneal thiopental or inhaled 1% halothane and mechanically ventilated for 4 or 8 h. SP-C mRNA expression was evaluated by ribonuclease protection assay. Results In vitro, 4-h exposure of alveolar type II cells to thiopental 10 and 100 micrometer increased their SP-C mRNA content to 145 and 197%, respectively, of the control values. In alveolar type II cells exposed for 4 h to halothane 1, 2, and 4%, the SP-C mRNA content increased dose-dependently to 160, 235, and 275%, respectively, of the control values. In vivo, in mechanically ventilated rats, 4 h of halothane anesthesia decreased the lung SP-C mRNA content to 53% of the value obtained in control (nonanesthetized, nonventilated) animals; thiopental anesthesia increased to 150% the lung SP-C mRNA content. Conclusions These findings indicate that halothane and thiopental used at clinically relevant concentrations modulate the pulmonary SP-C mRNA content in rats. In vivo, the additive role of mechanical ventilation is suggested.


2006 ◽  
Vol 189 (3) ◽  
pp. 807-817 ◽  
Author(s):  
Narisara Chantratita ◽  
Vanaporn Wuthiekanun ◽  
Khaemaporn Boonbumrung ◽  
Rachaneeporn Tiyawisutsri ◽  
Mongkol Vesaratchavest ◽  
...  

ABSTRACT Melioidosis is a notoriously protracted illness and is difficult to cure. We hypothesize that the causative organism, Burkholderia pseudomallei, undergoes a process of adaptation involving altered expression of surface determinants which facilitates persistence in vivo and that this is reflected by changes in colony morphology. A colony morphotyping scheme and typing algorithm were developed using clinical B. pseudomallei isolates. Morphotypes were divided into seven types (denoted I to VII). Type I gave rise to other morphotypes (most commonly type II or III) by a process of switching in response to environmental stress, including starvation, iron limitation, and growth at 42°C. Switching was associated with complex shifts in phenotype, one of which (type I to type II) was associated with a marked increase in production of factors putatively associated with in vivo concealment. Isogenic types II and III, derived from type I, were examined using several experimental models. Switching between isogenic morphotypes occurred in a mouse model, where type II appeared to become adapted for persistence in a low-virulence state. Isogenic type II demonstrated a significant increase in intracellular replication fitness compared with parental type I after uptake by epithelial cells in vitro. Isogenic type III demonstrated a higher replication fitness following uptake by macrophages in vitro, which was associated with a switch to type II. Mixed B. pseudomallei morphologies were common in individual clinical specimens and were significantly more frequent in samples of blood, pus, and respiratory secretions than in urine and surface swabs. These findings have major implications for therapeutics and vaccine development.


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