Daniela A. Bota

Clinical Practice Experience With NovoTTF-100A™ System for Glioblastoma: The Patient Registry Dataset (PRiDe)

Recurrent glioblastoma multiforme (GBM) is a highly aggressive cancer with poor prognosis, and an overall survival of 6 to 7 months with optimal therapies. The NovoTTF-100A™ System is a novel antimitotic cancer therapy recently approved for the treatment of recurrent GBM, based on phase III (EF-11) trial results. The Patient Registry Dataset (PRiDe) is a post-marketing registry of all recurrent GBM patients who received NovoTTF Therapy in a real-world, clinical practice setting in the United States between 2011 and 2013. Data were collected from all adult patients with recurrent GBM who began commercial NovoTTF Therapy in the United States between October 2011 and November 2013. All patients provided written consent before treatment was started. Overall survival (OS) curves were constructed for PRiDe using the Kaplan-Meier method. Median OS in PRiDe was compared for patients stratified by average daily compliance (≥75% v<75% per day) and other prognostic variables. Adverse events were also evaluated. Data from 457 recurrent GBM patients who received NovoTTF Therapy in 91 US cancer centers were analyzed. More patients in PRiDe than the EF-11 trial received NovoTTF Therapy for first recurrence (33% v 9%) and had received prior bevacizumab therapy (55.1% v 19%). Median OS was significantly longer with NovoTTF Therapy in clinical practice (PRiDe data set) than in the EF-11 trial (9.6 v 6.6 months; HR, 0.66; 95% CI, 0.05 to 0.86, P = .0003). One- and 2-year OS rates were more than double for NovoTTF Therapy patients in PRiDe than in the EF-11 trial (1-year: 44% v 20%; 2-year: 30% v 9%). First and second versus third and subsequent recurrences, high Karnofsky performance status (KPS), and no prior bevacizumab use were favorable prognostic factors. No unexpected adverse events were detected in PRiDe. As in the EF-11 trial, the most frequent adverse events were mild to moderate skin reactions associated with application of the NovoTTF Therapy transducer arrays. Results from PRiDe, together with those previously reported in the EF-11 trial, indicate that NovoTTF Therapy offers clinical benefit to patients with recurrent GBM. NovoTTF Therapy has high patient tolerability and favorable safety profile in the real-world, clinical practice setting.

Impairment of Lon-Induced Protection Against the Accumulation of Oxidized Proteins in Senescent Wi-38 Fibroblasts

Oxidative damage to mitochondrial proteins is thought to contribute to the aging process, but the Lon protease normally degrades such proteins. In early-passage WI-38 human lung fibroblasts, Lon expression is rapidly induced during H(2)O(2) stress, which prevents the accumulation of oxidized proteins and protects cell viability. In contrast, middle passage cells exhibit only sluggish induction of Lon expression in oxidative stress, and oxidized proteins initially accumulate. Late-passage, or senescent, cells have low basal levels of Lon and high levels of accumulated oxidized proteins; in response to oxidative stress, they fail to induce Lon expression and exhibit continually increasing accumulation of oxidized proteins. Senescent cells separated into two populations, one exhibiting normal mitochondrial mass and a second displaying significant loss of mitochondria; both populations had diminished mitochondrial transmembrane potential. These senescent changes are similar to the effects of Lon silencing in young cells. We suggest that loss of Lon stress inducibility is part of a pattern of diminishing stress adaptability that predisposes cells to senescence.

Retrospective analysis of the tolerability and activity of lacosamide in patients with brain tumors: clinical article.

OBJECT The object of this study was to determine the tolerability and activity of lacosamide in patients with brain tumors. METHODS The authors reviewed the medical records at 5 US academic medical centers with tertiary brain tumor programs, seeking all patients in whom a primary brain tumor had been diagnosed and who were taking lacosamide. RESULTS The authors identified 70 patients with primary brain tumors and reviewed seizure frequency and toxicities. The majority of the patients had gliomas (96%). Fifty-five (78%) had partial seizures only, and 12 (17%) had generalized seizures. Most of the patients (74%) were started on lacosamide because of recurrent seizures. Forty-six patients (66%) reported a decrease in seizure frequency, and 21 patients (30%) reported stable seizures. Most of the patients (54 [77%]) placed on lacosamide did not report any toxicities. CONCLUSIONS This retrospective analysis demonstrated that lacosamide was both well tolerated and active as an add-on antiepileptic drug (AED) in patients with brain tumors. Lacosamides novel mechanism of action will allow for concurrent use with other AEDs, as documented by its activity across many different types of AEDs used in this patient population. Larger prospective studies are warranted.

Mitochondrial Lon protease in human disease and aging: Including an etiologic classification of Lon-related diseases and disorders

The Mitochondrial Lon protease, also called LonP1 is a product of the nuclear gene LONP1. Lon is a major regulator of mitochondrial metabolism and response to free radical damage, as well as an essential factor for the maintenance and repair of mitochondrial DNA. Lon is an ATP-stimulated protease that cycles between being bound (at the inner surface of the inner mitochondrial membrane) to the mitochondrial genome, and being released into the mitochondrial matrix where it can degrade matrix proteins. At least three different roles or functions have been ascribed to Lon: 1) Proteolytic digestion of oxidized proteins and the turnover of specific essential mitochondrial enzymes such as aconitase, TFAM, and StAR; 2) Mitochondrial (mt)DNA-binding protein, involved in mtDNA replication and mitogenesis; and 3) Protein chaperone, interacting with the Hsp60-mtHsp70 complex. LONP1 orthologs have been studied in bacteria, yeast, flies, worms, and mammals, evincing the widespread importance of the gene, as well as its remarkable evolutionary conservation. In recent years, we have witnessed a significant increase in knowledge regarding Lons involvement in physiological functions, as well as in an expanding array of human disorders, including cancer, neurodegeneration, heart disease, and stroke. In addition, Lon appears to have a significant role in the aging process. A number of mitochondrial diseases have now been identified whose mechanisms involve various degrees of Lon dysfunction. In this paper we review current knowledge of Lons function, under normal conditions, and we propose a new classification of human diseases characterized by a either over-expression or decline or loss of function of Lon. Lon has also been implicated in human aging, and we review the data currently available as well as speculating about possible interactions of aging and disease. Finally, we also discuss Lon as potential therapeutic target in human disease.

First clinical results of a personalized immunotherapeutic vaccine against recurrent, incompletely resected, treatment-resistant glioblastoma multiforme (GBM) tumors, based on combined allo- and auto-immune tumor reactivity

Glioblastoma multiforme (GBM) patients have a poor prognosis. After tumor recurrence statistics suggest an imminent death within 1-4.5 months. Supportive preclinical data, from a rat model, provided the rational for a prototype clinical vaccine preparation, named Gliovac (or ERC 1671) composed of autologous antigens, derived from the patients surgically removed tumor tissue, which is administered together with allogeneic antigens from glioma tissue resected from other GBM patients. We now report the first results of the Gliovac treatment for treatment-resistant GBM patients. Nine (9) recurrent GBM patients, after standard of care treatment, including surgery radio- and chemotherapy temozolomide, and for US patients, also bevacizumab (Avastin™), were treated under a compassionate use/hospital exemption protocol. Gliovac was given intradermally, together with human GM-CSF (Leukine(®)), and preceded by a regimen of regulatory T cell-depleting, low-dose cyclophosphamide. Gliovac administration in patients that have failed standard of care therapies showed minimal toxicity and enhanced overall survival (OS). Six-month (26 weeks) survival for the nine Gliovac patients was 100% versus 33% in control group. At week 40, the published overall survival was 10% if recurrent, reoperated patients were not treated. In the Gliovac treated group, the survival at 40 weeks was 77%. Our data suggest that Gliovac has low toxicity and a promising efficacy. A phase II trial has recently been initiated in recurrent, bevacizumab naïve GBM patients (NCT01903330).

Epidemiology of Central Nervous System Metastases

Brain metastases are overwhelmingly the most common type of brain tumor, out numbering primary brain tumors in incidence by more than four-to-one. They are associated with poor prognosis both from a length-of-life as well as a quality-of-life standpoint. Once the brain metastasis is detected, without treatment, most patients die within months, either from widespread systemic disease, or due to the brain metastasis itself. The complications of brain metastases are also devastating. Patients can suffer from seizures, weakness or paralysis, language and communication deficits, as well as cognitive decline. These complications negatively impact on quality of life through effects on functional independence, impairment of capacity to participate in activities and relationships, as well as distortion of individual personality and identity. At the same time, there are great financial burdens associated with both the care and treatment of patients with brain metastases. Early detection of brain metastases in cancer patients is critical for limiting these complications, minimizing these burdens and improving the outlook regarding both survival and quality of life. Understanding the epidemiology of brain metastases can lead to the development of new strategies for the early identification and successful treatment of these patients.

Glioma Big Potassium Channel Expression in Human Cancers and Possible T Cell Epitopes for Their Immunotherapy

Big potassium (BK) ion channels have several spliced variants. One spliced variant initially described within human glioma cells is the glioma BK (gBK) channel. This isoform consists of 34 aa inserted into the intracellular region of the basic BK ion channel. PCR primers specific for this inserted region confirmed that human glioma cell lines and freshly resected surgical tissues from glioblastoma multiforme patients strongly expressed gBK mRNA. Normal human brain tissue very weakly expressed this transcript. An Ab specific for this gBK isoform confirmed that human glioma cells displayed this protein in the cell membrane, mitochondria, Golgi, and endoplasmic reticulum. Within the gBK region, two putative epitopes (gBK1 and gBK2) are predicted to bind to the HLA-A*0201 molecule. HLA-A*0201–restricted human CTLs were generated in vitro using gBK peptide-pulsed dendritic cells. Both gBK1 and gBK2 peptide-specific CTLs killed HLA-A2+/gBK+ gliomas, but they failed to kill non-HLA-A2–expressing but gBK+ target cells in cytolytic assays. T2 cells loaded with exogenous gBK peptides, but not with the influenza M1 control peptide, were only killed by their respective CTLs. The gBK-specific CTLs also killed a variety of other HLA-A*0201+ cancer cells that possess gBK, as well as HLA-A2+ HEK cells transfected with the gBK gene. Of clinical relevance, we found that T cells derived from glioblastoma multiforme patients that were sensitized to the gBK peptide could also kill target cells expressing gBK. This study shows that peptides derived from cancer-associated ion channels maybe useful targets for T cell-mediated immunotherapy.

Immunotherapy of brain cancers: the past, the present, and future directions.

Treatment of brain cancers, especially high grade gliomas (WHO stage III and IV) is slowly making progress, but not as fast as medical researchers and the patients would like. Immunotherapy offers the opportunity to allow the patients own immune system a chance to help eliminate the cancer. Immunotherapys strength is that it efficiently treats relatively small tumors in experimental animal models. For some patients, immunotherapy has worked for them while not showing long-term toxicity. In this paper, we will trace the history of immunotherapy for brain cancers. We will also highlight some of the possible directions that this field may be taking in the immediate future for improving this therapeutic option.

Low-doses of cisplatin injure hippocampal synapses: A mechanism for ‘chemo’ brain?

Chemotherapy-related cognitive deficits are a major neurological problem, but the underlying mechanisms are unclear. The death of neural stem/precursor cell (NSC) by cisplatin has been reported as a potential cause, but this requires high doses of chemotherapeutic agents. Cisplatin is frequently used in modern oncology, and it achieves high concentrations in the patients brain. Here we report that exposure to low concentrations of cisplatin (0.1μM) causes the loss of dendritic spines and synapses within 30min. Longer exposures injured dendritic branches and reduced dendritic complexity. At this low concentration, cisplatin did not affect NSC viability nor provoke apoptosis. However, higher cisplatin levels (1μM) led to the rapid loss of synapses and dendritic disintegration, and neuronal-but not NSC-apoptosis. In-vivo treatment with cisplatin at clinically relevant doses also caused a reduction of dendritic branches and decreased spine density in CA1 and CA3 hippocampal neurons. An acute increase in cell death was measured in the CA1 and CA3 neurons, as well as in the NSC population located in the subgranular zone of the dentate gyrus in the cisplatin treated animals. The density of dendritic spines is related to the degree of neuronal connectivity and function, and pathological changes in spine number or structure have significant consequences for brain function. Therefore, this synapse and dendritic damage might contribute to the cognitive impairment observed after cisplatin treatment.

TRIM11 is overexpressed in high-grade gliomas and promotes proliferation, invasion, migration and glial tumor growth

TRIM11 (tripartite motif-containing protein 11), an E3 ubiquitin ligase, is known to be involved in the development of the central nervous system. However, very little is known regarding the role of TRIM11 in cancer biology. Here, we examined the expression profile of TRIM11, along with two stem cell markers CD133 and nestin, in multiple glioma patient specimens, glioma primary cultures derived from tumors taken at surgery and normal neural stem/progenitor cells (NSCs). The oncogenic function of TRIM11 in glioma biology was investigated by knockdown and/or overexpression in vitro and in vivo experiments. Our results showed that TRIM11 expression levels were upregulated in malignant glioma specimens and in high-grade glioma-derived primary cultures, whereas remaining low in glioblastoma multiforme (GBM) stable cell lines, low-grade glioma-derived primary cultures and NSCs. The expression pattern of TRIM11 strongly correlated with that of CD133 and nestin and differentiation status of malignant glioma cells. Knock down of TRIM11 inhibited proliferation, migration and invasion of GBM cells, significantly decreased epidermal growth factor receptor (EGFR) levels and mitogen-activated protein kinase activity, and downregulated HB-EGF (heparin-binding EGF-like growth factor) mRNA levels. Meanwhile, TRIM11 overexpression promoted a stem-like phenotype in vitro (tumorsphere formation) and enhanced glial tumor growth in immunocompromised mice. These findings suggest that TRIM11 might be an indicator of glioma malignancy and has an oncogenic function mediated through the EGFR signaling pathway. TRIM11 overexpression potentially leads to a more aggressive glioma phenotype, along with increased malignant tumor growth and poor survival. Taken together, clarification of the biological function of TRIM11 and pathways it affects may provide novel therapeutic strategies for treating malignant glioma patients.