Detection and quantification of VEGFR-1 in the nuclei of tumor cells by a new flow cytometry-based method

Flow cytometry using fluorescent antibodies (FC) is the method of choice for the quantitation of proteins expressed at the surface or inside the cell, but, however, does not allow to selectively measure nuclear expression. We therefore sought to develop a method for the extraction of intact cell nuclei, which can be used for their subsequent immunofluorescent analysis by FC. The studied protein was vascular endothelial growth factor-receptor-type 1 (VEGFR-1) which is important in tumor survival and metastasis. Two human cell lines, A431 (epidermoid carcinoma of skin with low invasive and metastatic potential) and BRO (highly aggressive amelanotic melanoma), were used as examples for tumor cells, and normal human fibroblasts PHF served as a control line. The quality of the extracted nuclei was assessed by their intactness and purity from cytoplasm. The high content of the nuclear markers (PCNA = proliferating cell nuclear antigen, lamin A/C) in the extracted nuclei with almost complete absence of the cytoplasmic β-tubulin demonstrated that the protocol can be used to obtain a pure suspension of single intact cell nuclei. The measurement of the nuclear VEGFR-1 content revealed that it was present only in tumor cell nuclei and that in more malignant BRO cells the receptor content was 1.75 times higher than in A431 (p = 0.014). Thus, the developed method of extraction of cell nuclei for subsequent FC analysis is suitable for the quantitative evaluation of protein content in the native nucleus

Individualization of surgical treatment of patient, suffering gastric cancer

Проведений кореляційний аналіз молекулярних і морфологічних чинників злоякісності і ефективності розширених і комбінованих операцій з приводу раку шлунка (РШ). Хворим здійснювали розширену лімфодисекцію (ЛДС), а також мультиорганну резекцію (МР), компонентом якої була селективна перитонеоектомія. За місцево-поширеного РШ втручання доповнювали внутрішньо-черевно. гіпертермічною хіміоперфузією (ВЧГТХП). Доведено ефективність поєднаного застосування розширеної ЛДС та МР з приводу РШ. Проаналізовані показники виживання хворих на основі аналізу вмісту молекулярних маркерів (VEGFR, p53, Her2, Ki – 67) і стандартних гістологічних маркерів (стадія, ступінь, диференціювання пухлини тощо). Критерієм ефективності лікування визнані показники виживання хворих на РШ.Correlational analysis of molecular and morphological malignant factors and efficacy of extended and combined operations for gastric cancer (GC) was conducted. Extended lymphodissection and multiorgan resection (MR), including selective peritoneoectomy, was perfomed. For locally–spread GC the intervention was added by intraabdominal hypertermal chemoperfusion. Efficacy of combined application of extended lymphodissection and MR for GC was proved. The survival indices, basing on analysis of the molecular markers content (VEGFR, p53, Her2, Ki-67) and the standard histological markers (stage, degree of tumoral differentiation etc) were analyzed for these patients. Survival indices in the GC patients are considered the criteria of the treatment efficacy

Oxidative stress in retinal pigment epithelium cells increases exosome secretion and promotes angiogenesis in endothelial cells.

10 páginas, 5 figurasThe retinal pigment epithelium (RPE), a monolayer located between the photoreceptors and the choroid, is constantly damaged by oxidative stress, particularly because of reactive oxygen species (ROS). As the RPE, because of its physiological functions, is essential for the survival of the retina, any sustained damage may consequently lead to loss of vision. Exosomes are small membranous vesicles released into the extracellular medium by numerous cell types, including RPE cells. Their cargo includes genetic material and proteins, making these vesicles essential for cell-to-cell communication. Exosomes may fuse with neighbouring cells influencing their fate. It has been observed that RPE cells release higher amounts of exosomes when they are under oxidative stress. Exosomes derived from cultured RPE cells were isolated by ultracentrifugation and quantified by flow cytometry. VEGF receptors (VEGFR) were analysed by both flow cytometry and Western blot. RT-PCR and qPCR were conducted to assess mRNA content of VEGFRs in exosomes. Neovascularization assays were performed after applying RPE exosomes into endothelial cell cultures. Our results showed that stressed RPE cells released a higher amount of exosomes than controls, with a higher expression of VEGFR in the membrane, and enclosed an extra cargo of VEGFR mRNA. Angiogenesis assays confirmed that endothelial cells increased their tube formation capacity when exposed to stressed RPE exosomes.This work was supported by internal funding of the university, by the local department of education, Conselleria de Educaciò, Cultura i Sport, Valencia, Spain (GVA/2014/106), and partially by other external institutions: Instituto Nacional Carlos III (PI13/00617), Red de Investigacón Cardiovascular (RD12/0042/0052).Peer reviewe

Lapatinib-Binding Protein Kinases in the African Trypanosome: Identification of Cellular Targets for Kinase-Directed Chemical Scaffolds

Human African trypanosomiasis is caused by the eukaryotic microbe Trypanosoma brucei. To discover new drugs against the disease, one may use drugs in the clinic for other indications whose chemical scaffolds can be optimized via a medicinal chemistry campaign to achieve greater potency against the trypanosome. Towards this goal, we tested inhibitors of human EGFR and/or VEGFR as possible anti-trypanosome compounds. The 4-anilinoquinazolines canertinib and lapatinib, and the pyrrolopyrimidine AEE788 killed bloodstream T. brucei in vitro with GI(50) in the low micromolar range. Curiously, the genome of T. brucei does not encode EGFR or VEGFR, indicating that the drugs recognize alternate proteins. To discover these novel targets, a trypanosome lysate was adsorbed to an ATP-sepharose matrix and washed with a high salt solution followed by nicotinamide adenine dinucleotide (NAD(+)). Proteins that remained bound to the column were eluted with drugs, and identified by mass spectrometry/bioinformatics. Lapatinib bound to Tb927.4.5180 (termed T. brucei lapatinib-binding protein kinase-1 (TbLBPK1)) while AEE788 bound Tb927.5.800 (TbLBPK2). When the NAD(+) wash was omitted from the protocol, AEE788, canertinib and lapatinib eluted TbLBPK1, TbLBPK2, and Tb927.3.1570 (TbLBPK3). In addition, both canertinib and lapatinib eluted Tb10.60.3140 (TbLBPK4), whereas only canertinib desorbed Tb10.61.1880 (TbCBPK1). Lapatinib binds to a unique conformation of protein kinases. To gain insight into the structural basis for lapatinib interaction with TbLBPKs, we constructed three-dimensional models of lapatinib•TbLBPK complexes, which confirmed that TbLBPKs can adopt lapatinib-compatible conformations. Further, lapatinib, AEE788, and canertinib were docked to TbLBPKs with favorable scores. Our studies (a) present novel targets of kinase-directed drugs in the trypanosome, and (b) offer the 4-anilinoquinazoline and pyrrolopyrimidines as scaffolds worthy of medicinal chemistry and structural biology campaigns to develop them into anti-trypanosome drugs

Cell and molecular mechanisms of insulin-induced angiogenesis

Angiogenesis, the development of new blood vessel from pre-existing vessels, is a key process in the formation of the granulation tissue during wound healing. The appropriate development of new blood vessels, along with their subsequent maturation and differentiation, establishes the foundation for functional wound neovasculature. We performed studies in vivo and used a variety of cellular and molecular approaches in vitro to show that insulin stimulates angiogenesis and to elucidate the signalling mechanisms by which this protein stimulates microvessel development. Mice skin injected with insulin shows longer vessels with more branches, along with increased numbers of associated α-smooth muscle actin-expressing cells, suggesting the appropriate differentiation and maturation of the new vessels. We also found that insulin stimulates human microvascular endothelial cell migration and tube formation, and that these effects occur independently of VEGF/VEGFR signalling, but are dependent upon the insulin receptor itself. Downstream signalling pathways involve PI3K, Akt, sterol regulatory element-binding protein 1 (SREBP-1) and Rac1; inhibition of these pathways results in elimination of endothelial cell migration and tube formation and significantly decreases the development of microvessels. Our findings strongly suggest that insulin is a good candidate for the treatment of ischaemic wounds and other conditions in which blood vessel development is impaired

Tivozanib: First Global Approval

<div>Compliance with Ethical Standards</div><div><i><br></i></div><div><i>Funding:</i> The preparation of this review was not supported by any external funding.</div><div><i><br></i></div><div><i>Conflicts of interest</i>: During the peer review process the manufacturer of the agent under review was offered an opportunity to comment on the article. Changes resulting from any comments received were made by the author on the basis of scientific completeness and accuracy. Esther Kim is a salaried employee of Adis/Springer, is responsible for the article content and declares no relevant conflicts of interest.</div><div><br></div><div>Additional information about this Adis Drug Review can be found <b><a href="http://www.springer.com/gp/adis/products-services/adis-journals-newsletters/adis-drug-reviews">here</a>.</b></div><div><br></div><div>Abstract</div><div><br></div><div>Tivozanib (Fotivda®) is an oral, potent and highly selective vascular endothelial growth factor receptor (VEGFR) inhibitor that has been approved in the EU, Iceland and Norway for the first-line treatment of adult patients with advanced renal cell carcinoma (RCC) and for adult patients who are VEGFR and mammalian target of rapamycin (mTOR) pathway inhibitor-naive following disease progression after one prior treatment with cytokine therapy for advanced RCC. Tivozanib is at various stages of development in other countries for advanced RCC and advanced solid tumours. This article summarizes the milestones in the development of tivozanib leading to this first global approval in Europe for the treatment of adults with advanced RCC. Access to the full article can be found <b><a href="http://dx.doi.org/10.1007/s40265-017-0825-y">here</a>.</b></div><div><br></div><div>© Springer International Publishing AG, part of Springer Nature 2017</div><div><br></div

Sorafenib tosylate inhibits directly necrosome complex formation and protects in mouse models of inflammation and tissue injury

Necroptosis contributes to the pathophysiology of several inflammatory, infectious and degenerative disorders. TNF-induced necroptosis involves activation of the receptor-interacting protein kinases 1 and 3 (RIPK1/3) in a necrosome complex, eventually leading to the phosphorylation and relocation of mixed lineage kinase domain like protein (MLKL). Using a high-content screening of small compounds and FDA-approved drug libraries, we identified the anti-cancer drug Sorafenib tosylate as a potent inhibitor of TNF-dependent necroptosis. Interestingly, Sorafenib has a dual activity spectrum depending on its concentration. In murine and human cell lines it induces cell death, while at lower concentrations it inhibits necroptosis, without affecting NF-.B activation. Pull down experiments with biotinylated Sorafenib show that it binds independently RIPK1, RIPK3 and MLKL. Moreover, it inhibits RIPK1 and RIPK3 kinase activity. In vivo Sorafenib protects against TNF-induced systemic inflammatory response syndrome (SIRS) and renal ischemia-reperfusion injury (IRI). Altogether, we show that Sorafenib can, next to the reported Braf/Mek/Erk and VEGFR pathways, also target the necroptotic pathway and that it can protect in an acute inflammatory RIPK1/3-mediated pathology

Cabozantinib Resolves Bone Scans in Tumor-Naive Mice Harboring Skeletal Injuries

The receptor tyrosine kinase inhibitor cabozantinib (XL184, BMS-907351 Cometriq) has displayed impressive clinical activity against several indications, culminating in its recent approval for medullary thyroid cancer. Among malignancies with tropism for the bone (prostate, breast), one striking feature of early clinical reports about this drug has been the rapid and complete resolution of bone scans, a phenomenon almost never observed even among therapies already shown to confer survival benefit. In castration-resistant prostate cancer, not all conventional response indicators change as dramatically posttreatment, raising the possibility that cabozantinib may impair the ability of bone-seeking radionuclides to integrate within the remodeling bone. To test this hypothesis, we surgically induced bone remodeling via physical insult in non-tumor-bearing mice and performed F-18-sodium fluoride (F-18-NaF) positron emission tomographic (PET) and technetium 99m-methylene diphosphonate (Tc-99m-MDP) single-photon emission computed tomographic (SPECT) scans pre- and posttreatment with cabozantinib and related inhibitors. A consistent reduction in the accumulation of either radiotracer at the site of bone remodeling was observed in animals treated with cabozantinib. Given that cabozantinib is known to inhibit several receptor tyrosine kinases, we drugged animals with various permutations of more selective inhibitors to attempt to refine the molecular basis of bone scan resolution. Neither the vascular endothelial growth factor receptor (VEGFR) inhibitor axitinib, the MET inhibitor crizotinib, nor the combination was capable of inhibiting F-18-NaF accumulation at known bioactive doses. In summary, although the mechanism by which cabozantinib suppresses radionuclide incorporation into foci undergoing bone remodeling remains unknown, that this phenomenon occurs in tumor-naive models indicates that caution should be exercised in interpreting the clinical significance of this event