Mean global DNA methylation serves as independent prognostic marker in IDH-wildtype glioblastoma.

Background: The IDH-wildtype glioblastoma (GBM) patients have a devastating prognosis. Here, we analyzed the potential prognostic value of global DNA methylation of the tumors.

Methods: DNA methylation of 492 primary samples and 31 relapsed samples, each treated with combination therapy, and of 148 primary samples treated with radiation alone were compared with patient survival.

Patient-individual phenotypes of glioblastoma stem cells are conserved in culture and associate with radioresistance, brain infiltration and patient prognosis.

Identification of prognostic or predictive molecular markers in glioblastoma resection specimens may lead to strategies for therapy stratification and personalized treatment planning. Here, we analyzed in primary glioblastoma stem cell (pGSC) cultures the mRNA abundances of seven stem cell (MSI1, Notch1, nestin, Sox2, Oct4, FABP7 and ALDH1A3), and three radioresistance or invasion markers (CXCR4, IK and BK ). From these abundances, an mRNA signature was deduced which describes the mesenchymal-to-proneural expression profile of an individual GSC culture.

Repurposing Disulfiram for Targeting of Glioblastoma Stem Cells: An In Vitro Study.

Mesenchymal glioblastoma stem cells (GSCs), a subpopulation in glioblastoma that are responsible for therapy resistance and tumor spreading in the brain, reportedly upregulate aldehyde dehydrogenase isoform-1A3 (ALDH1A3) which can be inhibited by disulfiram (DSF), an FDA-approved drug formerly prescribed in alcohol use disorder. Reportedly, DSF in combination with Cu ions exerts multiple tumoricidal, chemo- and radio-therapy-sensitizing effects in several tumor entities. The present study aimed to quantify these DSF effects in glioblastoma stem cells in vitro, regarding dependence on ALDH1A3 expression.

Potassium Channels in Cancer.

Neoplastic transformation is reportedly associated with alterations of the potassium transport across plasma and intracellular membranes. These alterations have been identified as crucial elements of the tumourigenic reprogramming of cells. Potassium channels may contribute to cancer initiation, malignant progression and therapy resistance of tumour cells.

The Tumor Suppressor /ATIP1 Modulates Tumor Promotion in Glioma: Association with Epigenetics and DNA Repair.

Glioblastoma (GBM) is a highly aggressive brain tumor. Resistance mechanisms in GBM present an array of challenges to understand its biology and to develop novel therapeutic strategies. We investigated the role of a TSG, /ATIP1 in glioma.

γH2AX foci assay in glioblastoma: Surgical specimen versus corresponding stem cell culture.

Aim: To assess radiation response using γH2AX assay in surgical specimens from glioblastoma (GB) patients and their corresponding primary gliosphere culture. To test the hypothesis that gliospheres (stem cell enriched) are more resistant than specimens (bulky cell dominated) but that the interpatient heterogeneity is similar.

Material And Methods: Ten pairs of specimens and corresponding gliospheres derived from patients with IDH-wildtype GB were studied.

Against Repurposing Methadone for Glioblastoma Therapy.

Methadone, which is used as maintenance medication for outpatient treatment of opioid dependence or as an analgesic drug, has been suggested by preclinical in vitro and mouse studies to induce cell death and sensitivity to chemo- or radiotherapy in leukemia, glioblastoma, and carcinoma cells. These data together with episodical public reports on long-term surviving cancer patients who use methadone led to a hype of methadone as an anti-cancer drug in social and public media. However, clinical evidence for a tumoricidal effect of methadone is missing and prospective clinical trials, except in colorectal cancer, are not envisaged because of the limited preclinical data available.

Physiologically based pharmacokinetic model outputs depend on dissolution data and their input: Case examples glibenclamide and dipyridamole.

A plethora of dissolution tests exists for oral dosage forms, with variations in selection of the dissolution medium, the hydrodynamics and the dissolution equipment. This work aimed at determining the influence of media composition, the type of dissolution test and the method for entering the data into a PBPK model on the ability to simulate the in vivo plasma profile of an immediate release formulation. Using two rDCS IIa substances, glibenclamide and dipyridamole, housed in immediate-release formulations as model dosage forms, dissolution tests were performed in USP apparatus II with the biorelevant media FaSSGF, FaSSIF V1, V2 and V3 using both single-stage and two-stage test designs.

hERG K Channels Promote Survival of Irradiated Leukemia Cells.

Many tumor cells express highly elevated activities of voltage-gated K channels in the plasma membrane which are indispensable for tumor growth. To test for K channel function during DNA damage response, we subjected human chronic myeloid leukemia (CML) cells to sub-lethal doses of ionizing radiation (0-8 Gy, 6 MV photons) and determined K channel activity, K channel-dependent Ca signaling, cell cycle progression, DNA repair, and clonogenic survival by whole-cell patch clamp recording, fura-2 Ca imaging, Western blotting, flow cytometry, immunofluorescence microscopy, and pre-plating colony formation assay, respectively. As a result, the human erythroid CML cell line K562 and primary human CML cells functionally expressed hERG1.

Dissolution behavior of various drugs in different FaSSIF versions.

Biorelevant media have proven to be useful in predicting the performance of poorly soluble drugs in the gastrointestinal tract. Several versions of fasted state simulated intestinal fluids have been published and compared with respect to their physical chemical properties and solubilization of drugs. However, to date there have been no reports in the literature comparing dissolution of poorly soluble drugs in these media.

Biorelevant dissolution testing of a weak base: Interlaboratory reproducibility and investigation of parameters controlling in vitro precipitation.

Following a previous study which aimed to determine the interlaboratory reproducibility of biorelevant dissolution testing in the USP 2 apparatus for commercial formulations of two weak acids (ibuprofen and zafirlukast), this study attempts to determine the interlaboratory reproducibility using a similar protocol for a commercially available formulation of a weak base, indinavir. Fourteen partners including twelve industrial and two academic partners participated in this study. To ensure uniformity, all partners were provided with a standardized protocol to perform (i) a single medium dissolution test in fasted state simulated gastric and intestinal fluids (FaSSGF and FaSSIF, respectively) and (ii) a two-stage dissolution experiment simulating gastrointestinal transfer.

Alternating Electric Fields (TTFields) Activate Ca1.2 Channels in Human Glioblastoma Cells.

Tumor treating fields (TTFields) represent a novel FDA-approved treatment modality for patients with newly diagnosed or recurrent glioblastoma multiforme. This therapy applies intermediate frequency alternating electric fields with low intensity to the tumor volume by the use of non-invasive transducer electrode arrays. Mechanistically, TTFields have been proposed to impair formation of the mitotic spindle apparatus and cytokinesis.

Potential Role of CXCR4 Targeting in the Context of Radiotherapy and Immunotherapy of Cancer.

Cancer immunotherapy has been established as standard of care in different tumor entities. After the first reports on synergistic effects with radiotherapy and the induction of abscopal effects-tumor shrinkage outside the irradiated volume attributed to immunological effects of radiotherapy-several treatment combinations have been evaluated. Different immunotherapy strategies (e.

TRPM8 is required for survival and radioresistance of glioblastoma cells.

TRPM8 is a Ca-permeable nonselective cation channel belonging to the melastatin sub-group of the transient receptor potential (TRP) family. TRPM8 is aberrantly overexpressed in a variety of tumor entities including glioblastoma multiforme where it reportedly contributes to tumor invasion. The present study aimed to disclose further functions of TRPM8 in glioma biology in particular upon cell injury by ionizing radiation.

Cellular Effects of the Antiepileptic Drug Valproic Acid in Glioblastoma.

Background/aims: Valproic acid (VPA), an anticonvulsant and mood-stabilizing drug is used to treat epileptic seizure of glioblastoma patients. Besides its antiepileptic activity, VPA has been attributed further functions that improve the clinical outcome of glioblastoma patients. Those comprise the inhibition of some histone deacetylase (HDAC) isoforms which reportedly may result in radiosensitization.

KCa3.1 Channels and Glioblastoma: In Vitro Studies.

Background: Several tumor entities including brain tumors aberrantly overexpress intermediate conductance Ca2+ activated KCa3.1 K+ channels. These channels contribute significantly to the transformed phenotype of the tumor cells.

Validation of Dissolution Testing with Biorelevant Media: An OrBiTo Study.

Dissolution testing with biorelevant media has become widespread in the pharmaceutical industry as a means of better understanding how drugs and formulations behave in the gastrointestinal tract. Until now, however, there have been few attempts to gauge the reproducibility of results obtained with these methods. The aim of this study was to determine the interlaboratory reproducibility of biorelevant dissolution testing, using the paddle apparatus (USP 2).

Justification of disintegration testing beyond current FDA criteria using in vitro and in silico models.

Drug product performance testing is an important part of quality-by-design approaches, but this process often lacks the underlying mechanistic understanding of the complex interactions between the disintegration and dissolution processes involved. Whereas a recent draft guideline by the US Food and Drug Administration (FDA) has allowed the replacement of dissolution testing with disintegration testing, the mentioned criteria are not globally accepted. This study provides scientific justification for using disintegration testing rather than dissolution testing as a quality control method for certain immediate release (IR) formulations.

Ion Channels in Brain Metastasis.

Breast cancer, lung cancer and melanoma exhibit a high metastatic tropism to the brain. Development of brain metastases severely worsens the prognosis of cancer patients and constrains curative treatment options. Metastasizing to the brain by cancer cells can be dissected in consecutive processes including epithelial-mesenchymal transition, evasion from the primary tumor, intravasation and circulation in the blood, extravasation across the blood-brain barrier, formation of metastatic niches, and colonization in the brain.

K channel signaling in irradiated tumor cells.

K channels crosstalk with biochemical signaling cascades and regulate virtually all cellular processes by adjusting the intracellular K concentration, generating the membrane potential, mediating cell volume changes, contributing to Ca signaling, and directly interacting within molecular complexes with membrane receptors and downstream effectors. Tumor cells exhibit aberrant expression and activity patterns of K channels. The upregulation of highly "oncogenic" K channels such as the Ca-activated IK channel may drive the neoplastic transformation, malignant progression, metastasis, or therapy resistance of tumor cells.

BK K+ channel blockade inhibits radiation-induced migration/brain infiltration of glioblastoma cells.

Infiltration of the brain by glioblastoma cells reportedly requires Ca2+ signals and BK K+ channels that program and drive glioblastoma cell migration, respectively. Ionizing radiation (IR) has been shown to induce expression of the chemokine SDF-1, to alter the Ca2+ signaling, and to stimulate cell migration of glioblastoma cells. Here, we quantified fractionated IR-induced migration/brain infiltration of human glioblastoma cells in vitro and in an orthotopic mouse model and analyzed the role of SDF-1/CXCR4 signaling and BK channels.

Ca2+-Activated IK K+ Channel Blockade Radiosensitizes Glioblastoma Cells.

Unlabelled: Ca(2+)-activated K(+) channels, such as BK and IK channels, have been proposed to fulfill pivotal functions in neoplastic transformation, malignant progression, and brain infiltration of glioblastoma cells. Here, the ionizing radiation (IR) effect of IK K(+) channel targeting was tested in human glioblastoma cells. IK channels were inhibited pharmacologically by TRAM-34 or genetically by knockdown, cells were irradiated with 6 MV photons and IK channel activity, Ca(2+) signaling, cell cycling, residual double-strand breaks, and clonogenic survival were determined.

Role of ion channels in ionizing radiation-induced cell death.

Neoadjuvant, adjuvant or definitive fractionated radiation therapy are implemented in first line anti-cancer treatment regimens of many tumor entities. Ionizing radiation kills the tumor cells mainly by causing double strand breaks of their DNA through formation of intermediate radicals. Survival of the tumor cells depends on both, their capacity of oxidative defense and their efficacy of DNA repair.