elastin and Glioblastoma

Local tumor treatment is a feasible measure for patients with glioblastoma (GBM) who are unsuitable for surgical resection. Interferon-elastin-like polypeptide [IFN-ELP(V)] is a slow-release, biodegradable, thermosensitive fusion protein with antitumor immunity, and resveratrol (Res) is a polyphenolic compound with an antitumor effect. In this study, we found that intratumor injection of IFN-ELP(V) combined with intraperitoneal injection of Res is more effective in delaying GBM growth in mice. Specifically, in an orthotopic GBM model, we found a significant improvement in the median survival with this strategy. Our results suggested that the combined use of IFN-ELP(V) and Res has a dramatic synergistic effect on GBM, thus providing a novel and effective therapeutic strategy for tumors. Impact statement We report a novel and effective strategy in which the combined use of interferon-elastin-like polypeptide [IFN-ELP(V)] and Res effectively inhibits glioblastoma growth. IFN-ELP(V) can create a reservoir in the tumor and continuously release IFN to produce a powerful

Topics: Animals; Elastin; Glioblastoma; Interferons; Mice; Peptides; Resveratrol

To increase treatment efficiency for glioblastoma, we have developed a system to selectively deliver chemotherapeutic doxorubicin (Dox) to Glioblastoma (GBM) tumors. This carrier is based on elastin-like polypeptide (ELP), which is soluble at physiological temperatures but undergoes a phase transition and accumulates at tumor sites with externally applied, mild (40-41 °C) hyperthermia. The CPP-ELP-Dox conjugate consists of a cell penetrating peptide (CPP), which facilitates transcytosis through the blood brain barrier and cell entry, and a 6-maleimidocaproyl hydrazone derivative of doxorubicin at the C-terminus of ELP. The acid-sensitive hydrazone linker ensures release of Dox in the lysosomes/endosomes after cellular uptake of the drug conjugate. We have shown that CPP-ELP-Dox effectively inhibits cell proliferation in three GBM cell lines. Both the free drug and CPP-ELP-Dox conjugate exhibited similar in vitro cytotoxicity, although their subcellular localization was considerably different. The Dox conjugate was mainly dispersed in the cytoplasm, while free drug had partial nuclear accumulation in addition to cytoplasmic distribution. The intracellular Dox concentration was increased in the CPP-ELP-Dox cells compared to that in the cells treated with free Dox, which positively correlates with cytotoxic activity. In summary, our findings demonstrate that CPP-ELP-Dox effectively kills GBM cells. Development of such a drug carrier has the potential to greatly improve current therapeutic approaches for GBM by increasing the specificity and efficacy of treatment and reducing cytotoxicity in normal tissues.

Topics: Antibiotics, Antineoplastic; Brain Neoplasms; Cell Line, Tumor; Cell Nucleus; Cell Proliferation; Cell Survival; Cell-Penetrating Peptides; Cytoplasm; Doxorubicin; Drug Delivery Systems; Elastin; Glioblastoma; Humans; Molecular Structure; Solubility

Elastin-like polypeptide (ELP) nanoparticles are a versatile platform for targeted drug delivery. As for any type of nanocarrier system, an important challenge remains the ability of deep (tumor) tissue penetration. In this study, ELP particles with controlled surface density of the cell-penetrating peptide (CPP) octa-arginine (R8) were created by temperature-induced co-assembly. ELPs formed micellar nanoparticles with a diameter of around 60 nm. Cellular uptake in human skin fibroblasts was directly dependent on the surface density of R8 as confirmed by flow cytometry and confocal laser scanning microscopy. Remarkably, next to promoting cellular uptake, the presence of the CPP also enhanced penetration into spheroids generated from human glioblastoma U-87 cells. After 24 h, uptake into cells was observed in multiple layers towards the spheroid core. ELP particles not carrying any CPP did not penetrate. Clearly, a high CPP density exerted a dual benefit on cellular uptake and tissue penetration. At low nanoparticle concentration, there was evidence of a binding site barrier as observed for the penetration of molecules binding with high affinity to cell surface receptors. In conclusion, R8-functionalized ELP nanoparticles form an excellent delivery vehicle that combines tunability of surface characteristics with small and well-defined size.

Topics: Binding Sites; Cell Line, Tumor; Cell-Penetrating Peptides; Chemistry, Pharmaceutical; Drug Delivery Systems; Elastin; Flow Cytometry; Glioblastoma; Humans; Microscopy, Confocal; Nanoparticles; Oligopeptides; Spheroids, Cellular; Time Factors

Notch pathway was found to be activated in most glioblastomas (GBMs), underlining the importance of Notch in formation and recurrence of GBM. In this study, a Notch inhibitory peptide, dominant negative MAML (dnMAML), was conjugated to elastin-like polypeptide (ELP) for tumor targeted delivery. ELP is a thermally responsive polypeptide that can be actively and passively targeted to the tumor site by localized application of hyperthermia. This complex was further modified with the addition of a cell penetrating peptide, SynB1, for improved cellular uptake and blood-brain barrier penetration. The SynB1-ELP1-dnMAML was examined for its cellular uptake, cytotoxicity, apoptosis, cell cycle inhibition and the inhibition of target genes' expression. SynB1-ELP1-dnMAML inhibited the growth of D54 and U251 cells by inducing apoptosis and cell cycle arrest, especially in the presence of hyperthermia. Hyperthermia increased overall uptake of the polypeptide by the cells and enhanced the resulting pharmacological effects of dnMAML, showing the inhibition of targets of Notch pathway such as Hes-1 and Hey-L. These results confirm that dnMAML is an effective Notch inhibitor and combination with ELP may allow thermal targeting of the SynB1-ELP1-dnMAML complex in cancer cells while avoiding the dangers of systemic Notch inhibition.

Topics: Apoptosis; Blood-Brain Barrier; Brain Neoplasms; Cell Cycle Checkpoints; Cell Line, Tumor; Cell-Penetrating Peptides; DNA-Binding Proteins; Drug Delivery Systems; Elastin; Glioblastoma; Humans; Hyperthermia, Induced; Peptides; Receptors, Notch; Transcription Factors

Topics: Abdominal Wall; Adult; Antibodies, Antinuclear; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Biopsy; Brain Neoplasms; Dexamethasone; Disease Progression; Drug Eruptions; Drug Interactions; Elastin; Etoposide; Fatal Outcome; Glioblastoma; Humans; Male; Neoplasm Staging; Ribonucleoproteins; Skin; Skin Ulcer; Striae Distensae

In the most common primary brain tumors, malignant glioma cells invade the extracellular matrix (ECM) and proliferate rapidly in the cerebral tissue, which is mainly composed of hyaluronan (HA) along with the elastin present in the basement membrane of blood vessels. To determine the role of ECM components in the invasive capacity of glioma cell lines, we developed a 3-D cell-culture system, based on a hydrogel in which HA can be coreticulated with kappa-elastin (HA-kappaE). Using this system, the invasiveness of cells from four glioma cell lines was dramatically increased by the presence of kappaE and a related, specific peptide (VGVAPG)(3). In addition, MMP-2 secretion increased and MMP-12 synthesis occurred. Extracellular injections of kappaE or (VGVAPG)(3) provoked a pronounced and dose-dependent increase in [Ca(2+)](i). kappaE significantly enhanced the expression of the genes encoding elastin-receptor and tropoelastin. We propose the existence of a positive feedback loop in which degradation of elastin generates fragments that stimulate synthesis of tropoelastin followed by further degradation as well as migration and proliferation of the very cells responsible for degradation. All steps in this ECM-based loop could be blocked by the addition of either of the EBP antagonists, lactose, and V-14 peptide, suggesting that the loop itself should be considered as a new therapeutic target.

Topics: Calcium; Cell Adhesion; Cell Culture Techniques; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cells, Cultured; Dose-Response Relationship, Drug; Elastin; Extracellular Matrix; Glioblastoma; Humans; Matrix Metalloproteinase 12; Matrix Metalloproteinase 2; Neoplasm Invasiveness; Oligopeptides; Receptors, Cell Surface; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Statistics, Nonparametric; Tropoelastin

In 20 patients with brain tumors contrast enhancement in computer tomography CT is compared to the occurrence of elastin fibers in the tumor on microscopic examination. The results give rise to the statement that the perivascular and intercellular space is of importance for contrast enhancement in CT.

Topics: Blood-Brain Barrier; Brain Neoplasms; Contrast Media; Elastin; Glioblastoma; Humans; Tomography, X-Ray Computed