scholarly journals Monotherapy efficacy of blood–brain barrier permeable small molecule reactivators of protein phosphatase 2A in glioblastoma

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Joni Merisaari ◽  
Oxana V Denisova ◽  
Milena Doroszko ◽  
Vadim Le Joncour ◽  
Patrik Johansson ◽  
...  

Abstract Glioblastoma is a fatal disease in which most targeted therapies have clinically failed. However, pharmacological reactivation of tumour suppressors has not been thoroughly studied as yet as a glioblastoma therapeutic strategy. Tumour suppressor protein phosphatase 2A is inhibited by non-genetic mechanisms in glioblastoma, and thus, it would be potentially amendable for therapeutic reactivation. Here, we demonstrate that small molecule activators of protein phosphatase 2A, NZ-8-061 and DBK-1154, effectively cross the in vitro model of blood–brain barrier, and in vivo partition to mouse brain tissue after oral dosing. In vitro, small molecule activators of protein phosphatase 2A exhibit robust cell-killing activity against five established glioblastoma cell lines, and nine patient-derived primary glioma cell lines. Collectively, these cell lines have heterogeneous genetic background, kinase inhibitor resistance profile and stemness properties; and they represent different clinical glioblastoma subtypes. Moreover, small molecule activators of protein phosphatase 2A were found to be superior to a range of kinase inhibitors in their capacity to kill patient-derived primary glioma cells. Oral dosing of either of the small molecule activators of protein phosphatase 2A significantly reduced growth of infiltrative intracranial glioblastoma tumours. DBK-1154, with both higher degree of brain/blood distribution, and more potent in vitro activity against all tested glioblastoma cell lines, also significantly increased survival of mice bearing orthotopic glioblastoma xenografts. In summary, this report presents a proof-of-principle data for blood–brain barrier—permeable tumour suppressor reactivation therapy for glioblastoma cells of heterogenous molecular background. These results also provide the first indications that protein phosphatase 2A reactivation might be able to challenge the current paradigm in glioblastoma therapies which has been strongly focused on targeting specific genetically altered cancer drivers with highly specific inhibitors. Based on demonstrated role for protein phosphatase 2A inhibition in glioblastoma cell drug resistance, small molecule activators of protein phosphatase 2A may prove to be beneficial in future glioblastoma combination therapies.

2019 ◽  
Author(s):  
Michael M Lübtow ◽  
Sabrina Oertner ◽  
Sabina Quader ◽  
Elisabeth Jeanclos ◽  
Alevtina Cubukova ◽  
...  

Inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase of the family of statins have been suggested as therapeutic options in various tumors. Atorvastatin is a statin with potential to cross the blood-brain-barrier, however, the concentrations necessary for a cytotoxic effect against cancer cells exceeds the concentration achievable via oral administration, which made the development of a novel atorvastatin formulation necessary. We characterized the drug loading and basic physicochemical characteristics of micellar atorvastatin formulations and tested their cytotoxicity against a panel of different glioblastoma cell lines. In addition, activity against tumor spheroids formed from mouse glioma and mouse cancer stem cells, respectively, was evaluated. Our results show good activity of atorvastatin against all tested cell lines. Interestingly, in the 3D models, growth inhibition was more pronounced for the micellar formulation compared to free atorvastatin. Finally, atorvastatin penetration across a blood-brain-barrier model obtained from human induced-pluripotent stem cells was evaluated. Our results suggest that the presented micelles may enable much higher serum concentrations than possible by oral administration, however, if transport across the blood-brain-barrier is sufficient to reach therapeutic atorvastatin concentration for the treatment of glioblastoma via intravenous administration remains unclear.<br>


2003 ◽  
Vol 31 (3) ◽  
pp. 273-276 ◽  
Author(s):  
Hanna Tähti ◽  
Heidi Nevala ◽  
Tarja Toimela

The purpose of this paper is to review the current state of development of advanced in vitro blood–brain barrier (BBB) models. The BBB is a special capillary bed that separates the blood from the central nervous system (CNS) parenchyma. Astrocytes maintain the integrity of the BBB, and, without astrocytic contacts, isolated brain capillary endothelial cells in culture lose their barrier characteristics. Therefore, when developing in vitro BBB models, it is important to add astrocytic factors into the culture system. Recently, novel filter techniques and co-culture methods have made it possible to develop models which resemble the in vivo functions of the BBB in an effective way. With a BBB model, kinetic factors can be added into the in vitro batteries used for evaluating the neurotoxic potential of chemicals. The in vitro BBB model also represents a useful tool for the in vitro prediction of the BBB permeability of drugs, and offers the possibility to scan a large number of drugs for their potential to enter the CNS. Cultured monolayers of brain endothelial cell lines or selected epithelial cell lines, combined with astrocyte and neuron cultures, form a novel three-dimensional technique for the screening of neurotoxic compounds.


2016 ◽  
Vol 1642 ◽  
pp. 532-545 ◽  
Author(s):  
Nurul Adhwa Rahman ◽  
Alifah Nur’ain Haji Mat Rasil ◽  
Uta Meyding-Lamade ◽  
Eva Maria Craemer ◽  
Suwarni Diah ◽  
...  

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 403 ◽  
Author(s):  
Olufemi Alamu ◽  
Mariam Rado ◽  
Okobi Ekpo ◽  
David Fisher

Oxidative stress (OS) has been linked to blood–brain barrier (BBB) dysfunction which in turn has been implicated in the initiation and propagation of some neurological diseases. In this study, we profiled, for the first time, two endothelioma cell lines of mouse brain origin, commonly used as in vitro models of the blood–brain barrier, for their resistance against oxidative stress using viability measures and glutathione contents as markers. OS was induced by exposing cultured cells to varying concentrations of hydrogen peroxide and fluorescence microscopy/spectrometry was used to detect and estimate cellular glutathione contents. A colorimetric viability assay was used to determine changes in the viability of OS-exposed cells. Both the b.End5 and bEnd.3 cell lines investigated showed demonstrable content of glutathione with a statistically insignificant difference in glutathione quantity per unit cell, but with a statistically significant higher capacity for the b.End5 cell line for de novo glutathione synthesis. Furthermore, the b.End5 cells demonstrated greater oxidant buffering capacity to higher concentrations of hydrogen peroxide than the bEnd.3 cells. We concluded that mouse brain endothelial cells, derived from different types of cell lines, differ enormously in their antioxidant characteristics. We hereby recommend caution in making comparisons across BBB models utilizing distinctly different cell lines and require further prerequisites to ensure that in vitro BBB models involving these cell lines are reliable and reproducible.


2019 ◽  
Author(s):  
Michael M Lübtow ◽  
Sabrina Oertner ◽  
Sabina Quader ◽  
Elisabeth Jeanclos ◽  
Alevtina Cubukova ◽  
...  

Inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase of the family of statins have been suggested as therapeutic options in various tumors. Atorvastatin is a statin with potential to cross the blood-brain-barrier, however, the concentrations necessary for a cytotoxic effect against cancer cells exceeds the concentration achievable via oral administration, which made the development of a novel atorvastatin formulation necessary. We characterized the drug loading and basic physicochemical characteristics of micellar atorvastatin formulations and tested their cytotoxicity against a panel of different glioblastoma cell lines. In addition, activity against tumor spheroids formed from mouse glioma and mouse cancer stem cells, respectively, was evaluated. Our results show good activity of atorvastatin against all tested cell lines. Interestingly, in the 3D models, growth inhibition was more pronounced for the micellar formulation compared to free atorvastatin. Finally, atorvastatin penetration across a blood-brain-barrier model obtained from human induced-pluripotent stem cells was evaluated. Our results suggest that the presented micelles may enable much higher serum concentrations than possible by oral administration, however, if transport across the blood-brain-barrier is sufficient to reach therapeutic atorvastatin concentration for the treatment of glioblastoma via intravenous administration remains unclear.<br>


2020 ◽  
Vol 48 (4) ◽  
pp. 184-200
Author(s):  
Adrián García-Salvador ◽  
Alazne Domínguez-Monedero ◽  
Paloma Gómez-Fernández ◽  
Amaia García-Bilbao ◽  
Susana Carregal-Romero ◽  
...  

In vitro blood–brain barrier (BBB) models are a useful tool to screen the permeability and toxicity of new drugs. Currently, many different in vitro BBB models coexist, but none stands out as being notably better than the rest. Therefore, there is still a need to evaluate the quality of BBB models under various conditions and assess their ability to mimic the in vivo situation. In this study, two brain endothelial cell lines (bEnd.3 and hCMEC/D3) and two epithelial-like cell lines (MDCKII and Caco-2) were selected for BBB modelling purposes. They were grown as monolayers of a single cell type, under the following conditions: in coculture with either primary or immortalised astrocytes; or in the presence of primary or immortalised astrocyte-derived conditioned media. A total of 20 different BBB models were established in this manner, in order to assess the effects of the astroglial components on the BBB phenotype in each case. To this end, six parameters were studied: the expression of selected tight junction proteins; the enzyme activities of alkaline phosphatase and of gamma glutamyl transpeptidase; the transendothelial/transepithelial electrical resistance (TEER); restriction in paracellular transport; and efflux transporter inhibition were each evaluated and correlated. The results showed that coculturing with either primary or immortalised astrocytes led to a general improvement in all parameters studied, evidencing the contribution of this cell type to effective BBB formation. Furthermore, the permeability coefficient ( P e) of the tracer molecule, Lucifer Yellow, correlated with three of the six parameters studied. In addition, this study highlights the potential for the use of the Lucifer Yellow P e value as an indicator of barrier integrity in in vitro BBB models, which could be useful for screening the permeability of new drugs.


2021 ◽  
Author(s):  
Huaiying Zhang ◽  
Winant L. van Os ◽  
Xiaobo Tian ◽  
Guangyue Zu ◽  
Laís Ribovski ◽  
...  

Zein-polydopamine nanoparticles functionalized with G23 peptide cross an in vitro blood–brain barrier and penetrate tumor spheroids. When loaded with curcumin they effectively reduce proliferation, migration, and viability of C6 glioma cells.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xin Wang ◽  
Jie Lu ◽  
Jing Li ◽  
Yang Liu ◽  
Gaochao Guo ◽  
...  

AbstractRecent studies have showed that IKBKE is overexpressed in several kinds of cancers and that IKBKE-knockdown inhibits tumor progression. In this article, we first verified that two glioblastoma cell lines, U87-MG and LN-229, were sensitive to CYT387 by measuring the half maximal inhibitory concentration (IC50) with a CCK-8 assay and then demonstrated that CYT387, as a potent IKBKE inhibitor, suppressed glioblastoma cell proliferation, migration and invasion. Additionally, CYT387 induced cell apoptosis and arrested the cell cycle at the G2/M checkpoint in vitro. Furthermore, we showed that CYT387 did not simply inhibit IKBKE activity but also decreased IKBKE expression at the protein level rather than at the mRNA level. We discovered that CYT387 restrained malignant tumor progression by activating the Hippo pathway in vitro. By coimmunoprecipitation (co-IP), we showed that IKBKE interacted with TEAD2 and YAP1, thus accelerating TEAD2 and YAP1 transport into the nucleus. In subsequent in vivo experiments, we found that CYT387 inhibited subcutaneous nude mouse tumor growth but had little impact on intracranial orthotopic xenografts, probably due to a limited ability to penetrate the blood–brain barrier (BBB). These results suggest that CYT387 has potential as a new antiglioblastoma drug, but an approach to allow passage through the blood–brain barrier (BBB) is needed.


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