8 research outputs found
Identification of a broad lipid repertoire associated to the endothelial cell protein C receptor (EPCR)
Evidence is mounting that the nature of the lipid bound to the endothelial cell protein C receptor (EPCR) has an impact on its biological roles, as observed in anticoagulation and more recently, in autoimmune disease. Phosphatidylethanolamine and phosphatidylcholine species dominate the EPCR lipid cargo, yet, the extent of diversity in the EPCR-associated lipid repertoire is still unknown and remains to be uncovered. We undertook mass spectrometry analyses to decipher the EPCR lipidome, and identified species not yet described as EPCR ligands, such as phosphatidylinositols and phosphatidylserines. Remarkably, we found further, more structurally divergent lipids classes, represented by ceramides and sphingomyelins, both in less abundant quantities. In support of our mass spectrometry results and previous studies, high-resolution crystal structures of EPCR in three different space groups point to a prevalent diacyl phospholipid moiety in EPCRÂżs pocket but a mobile and ambiguous lipid polar head group. In sum, these studies indicate that EPCR can associate with varied lipid classes, which might impact its properties in anticoagulation and the onset of autoimmune disease.RamĂłn y Cajal, Grant RYCâ2017â21683, Ministry of Science and Innovation, Government of Spain (JLS). GeneraciĂłn de Conocimiento, Ministry of Science and Innovation, Government of Spain, Grant PGC2018-094894-B-I00 (JLS and EEA). Ministry of Science, Innovation and Universities of Spain (MICINN) and The European Regional Development Fund (FEDER) funding Grant RTI2018-095166-B-I00 (Antonia GarcĂa y Francisco Javier RupĂ©rez). Predoctoral Fellowship, Ministry of Universities, Government of Spain, Grant FPU19/06206 (MMG). Alejandro Urdiciain is a recipient of a Margarita Salas contract funded by UPNA and the Ministry of Universities of Spain within the Plan of Recovery, Transformation and Resilience and the European Recovery Instrument Next Generation EU
Panobinostat potentiates temozolomide effects and reverses epithelial-mesenchymal transition in glioblastoma cells
Glioblastoma is the most common form of glioma, as well as the most aggressive. Patients
suffering from this disease have a very poor prognosis. Surgery, radiotherapy, and temozolomide
are the only approved treatments nowadays. Panobinostat is a pan-inhibitor of histone deacetylases
(HDACs) that has been shown to break some pathways which play an important role in cancer
development. A global intention of using panobinostat as a therapeutic agent against glioblastoma
is beginning to be a reality. We have treated the LN405 glioblastoma cell line with temozolomide,
panobinostat, and combined treatment, in order to test apoptosis, colony formation, and a possible
molecular reversion of the mesenchymal phenotype of the cells to an epithelial one. Our results
show that panobinostat decreased N-cadherin levels in the LN405 glioblastoma cell line while it
increased the expression of E-cadherin, which might be associated with a mesenchymalâepithelial
transition in glioblastoma cells. Colony formation was reduced, and apoptosis was increased with
treatments. Our research highlights the importance of panobinostat as a potential adjuvant therapy
to be used with temozolomide to treat glioblastoma and the advantages of the combined treatment
versus temozolomide alone, which is currently the first-line treatment used to treat this tumo
El papel de la histona desacetilasa 6 en el desarrollo del gioblastoma
Glioblastoma multiforme, the most common type of malignant brain tumor as well as the most aggressive one, lacks an effective therapy. Glioblastoma presents overexpression of mesenchymal markers Snail, Slug and N-Cadherin, and of the autophagic marker p62. Glioblastoma cell lines also present an increased autophagic flux, overexpression of mesenchymal markers, Shh pathway activation and lack of primary cilia. In this study, we aimed to evaluate the role of histone deacetylase 6 (HDAC6) in the development of glioblastoma, as HDAC6 is the most overexpressed of all HDACs isoforms in this tumor. We treated glioblastoma cell lines with siHDAC6 and tubastatin A, a HDAC6 inhibitor. Both treatments inhibited proliferation, migration and clonogenicity of glioblastoma cell lines. They also reversed the mesenchymal phenotype, decreased the autophagic flux, inhibited Shh pathway and recovered the expression of primary cilia in glioblastoma cell lines. The treatment of tubastatin A also sensitized glioblastoma cell lines to temozolomide treatment, the chemotherapeutic agent used against glioblastoma. These results demonstrate that HDAC6 might be a good target for glioblastoma treatment
Panobinostat potentiates temozolomide effects and reverses epithelial-mesenchymal transition in glioblastoma cells
Glioblastoma is the most common form of glioma, as well as the most aggressive. Patients
suffering from this disease have a very poor prognosis. Surgery, radiotherapy, and temozolomide
are the only approved treatments nowadays. Panobinostat is a pan-inhibitor of histone deacetylases
(HDACs) that has been shown to break some pathways which play an important role in cancer
development. A global intention of using panobinostat as a therapeutic agent against glioblastoma
is beginning to be a reality. We have treated the LN405 glioblastoma cell line with temozolomide,
panobinostat, and combined treatment, in order to test apoptosis, colony formation, and a possible
molecular reversion of the mesenchymal phenotype of the cells to an epithelial one. Our results
show that panobinostat decreased N-cadherin levels in the LN405 glioblastoma cell line while it
increased the expression of E-cadherin, which might be associated with a mesenchymalâepithelial
transition in glioblastoma cells. Colony formation was reduced, and apoptosis was increased with
treatments. Our research highlights the importance of panobinostat as a potential adjuvant therapy
to be used with temozolomide to treat glioblastoma and the advantages of the combined treatment
versus temozolomide alone, which is currently the first-line treatment used to treat this tumo
Tubastatin A, an inhibitor of HDAC6, enhances temozolomideâinduced apoptosis and reverses the malignant phenotype of glioblastoma cells
Glioblastoma or grade IV astrocytoma is the most
common and lethal form of glioma. Current glioblastoma
treatment strategies use surgery followed by chemotherapy
with temozolomide. Despite this, numerous glioblastoma cases
develop resistance to temozolomide treatments, resulting in a
poor prognosis for the patients. Novel approaches are being
investigated, including the inhibition of histone deacetylase 6
(HDAC6), an enzyme that deacetylates α-tubulin, and
whose overexpression in glioblastoma is associated with the
loss of primary cilia. The aim of the present study was to
treat glioblastoma cells with a selective HDAC6 inhibitor,
tubastatin A, to determine if the malignant phenotype may
be reverted. The results demonstrated a notable increase in
acetylated α-tubulin levels in treated cells, which associated
with downregulation of the sonic hedgehog pathway, and may
hypothetically promote ciliogenesis in those cells. Treatment
with tubastatin A also reduced glioblastoma clonogenicity and
migration capacities, and accelerated temozolomide-induced
apoptosis. Finally, HDAC6 inhibition decreased the
expression of mesenchymal markers, contributing to reverse
epithelial-mesenchymal transition in glioblastoma cells
The synergistic effect of DZâNEP, panobinostat and temozolomide reduces clonogenicity and induces apoptosis in glioblastoma cells
Current treatment against glioblastoma consists of
surgical resection followed by temozolomide, with or without
combined radiotherapy. Glioblastoma frequently acquires
resistance to chemotherapy and/or radiotherapy. Novel therapeutic approaches are thus required. The inhibition of enhancer
of zeste homolog 2 (EZH2; a histone methylase) and histone
deacetylases (HDACs) are possible epigenetic treatments.
Temozolomide, 3-deazaneplanocin A (DZ-Nep; an EZH2
inhibitor) and panobinostat (an HDAC inhibitor) were tested
in regular and temozolomide-resistant glioblastoma cells to
confirm whether the compounds could behave in a synergistic,
additive or antagonistic manner. A total of six commercial
cell lines, two temozolomide-induced resistant cell lines and
two primary cultures derived from glioblastoma samples were
used. Cell lines were exposed to single treatments of the drugs
in addition to all possible two- and three-drug combinations.
Colony formation assays, synergistic assays and reverse transcription-quantitative PCR analysis of apoptosis-associated
genes were performed. The highest synergistic combination
was DZ-Nep + panobinostat. Triple treatment was also synergistic. Reduced clonogenicity and increased apoptosis were
both induced. It was concluded that the therapeutic potential
of the combination of these three drugs in glioblastoma was
evident and should be further explored
APR-246 combined with 3-deazaneplanocin A, panobinostat or temozolomide reduces clonogenicity and induces apoptosis in glioblastoma cells
Glioblastoma is the most malignant brain tumor and presents high resistance to chemotherapy and radiotherapy. Surgery, radiotherapy and chemotherapy with temozolomide are the only treatments against this tumor. New targeted therapies, including epigenetic modulators such as 3âdeazaneplanocin A (DZâNep; an EZH2 inhibitor) and panobinostat (a histone deacetylase inhibitor) are being tested in vitro, together with temozolomide. The present study combined APRâ246 with DZâNep, panobinostat and teomozolomide in order to explore the possibility of restoring p53 function in mutated cases of glioblastoma. Following the ChouâTalalay method it was demonstrated that APRâ246 acts in an additive manner together with the other compounds, reducing clonogenicity and inducing apoptosis in glioblastoma cells independently of p53 status
Silencing of histone deacetylase 6 decreases cellular malignancy and contributes to primary cilium restoration, epithelial-to-mesenchymal transition reversion, and autophagy inhibition in glioblastoma cell lines
Glioblastoma multiforme, the most common type of malignant brain tumor as well as the
most aggressive one, lacks an effective therapy. Glioblastoma presents overexpression of mesenchymal markers Snail, Slug, and N-Cadherin and of the autophagic marker p62. Glioblastoma cell lines
also present increased autophagy, overexpression of mesenchymal markers, Shh pathway activation,
and lack of primary cilia. In this study, we aimed to evaluate the role of HDAC6 in the pathogenesis of
glioblastoma, as HDAC6 is the most overexpressed of all HDACs isoforms in this tumor. We treated
glioblastoma cell lines with siHDAC6. HDAC6 silencing inhibited proliferation, migration, and
clonogenicity of glioblastoma cell lines. They also reversed the mesenchymal phenotype, decreased
autophagy, inhibited Shh pathway, and recovered the expression of primary cilia in glioblastoma cell
lines. These results demonstrate that HDAC6 might be a good target for glioblastoma treatment