The Influence of EGFR Inactivation on the Radiation Response in High Grade Glioma.

Lack of effectiveness of radiation therapy may arise from different factors such as radiation induced receptor tyrosine kinase activation and cell repopulation; cell capability to repair radiation induced DNA damage; high grade glioma (HGG) tumous heterogeneity, etc. In this study, we analyzed the potential of targeting epidermal growth factor receptor (EGFR) in inducing radiosensitivity in two human HGG cell lines (11 and 15) that displayed similar growth patterns and expressed the receptor protein at the cell surface. We found that 15 HGG cells that express more EGFR at the cell surface were more sensitive to AG556 (an EGFR inhibitor), compared to 11 HGG cells. Although in line 15 the effect of the inhibitor was greater than in line 11, it should be noted that the efficacy of this small-molecule EGFR inhibitor as monotherapy in both cell lines has been modest, at best. Our data showed a slight difference in the response to radiation of the HGG cell lines, three days after the treatment, with line 15 responding better than line 11. However, both cell lines responded to ionizing radiation in the same way, seven days after irradiation. EGFR inhibition induced radiosensitivity in 11 HGG cells, while, in 15 HGG cells, the effect of AG556 treatment on radiation response was almost nonexistent.

Two girl patients with medulloblastoma. Case reports.

In childhood, the most common type of brain tumors is medulloblastoma, a highly malignant primary brain tumor that is found in the cerebellum or posterior fossa. The tumor mass increases and generates obstructive hydrocephalus. Risk factors (that might be involved in some cases) include the genetic syndrome such as type 1 neurofibromatosis, exposure to ionizing radiation and Epstein-Barr virus. Medulloblastoma is associated with recessively inherited Turcot disease and with conditions as ataxia-telangiectasia syndrome in several cases. The authors presented two cases of female patients (aged one year and eight months old, respectively 4-year-old), both of them with weight deficiency, with personal history of head trauma. First case, M.D.M., was admitted in Emergency Room of the Emergency County Hospital, Craiova, Romania, for symptoms that included headaches, impaired vision, vomiting, mental disorders, ataxia and body imbalance. The reason for refer to the Surgical Unit care was posterior fossa tumor diagnosed by computed tomography (CT) scan. The second case, V.F., a 4-year-old girl, was admitted to First Pediatrics Clinic of the same Hospital, on October 2014, for seizures, early morning vomiting, loss of appetite, inability to walk and stand and also, mental delay. She had "café au lait" spots on her trunk, suggesting type 1 neurofibromatosis. A brain CT scan revealed a tumor being developed in the fourth ventricle (in the vermis of the cerebellum). Both the girls underwent curative surgery in different Clinics from Bucharest. The two girls with the same diagnosis showed contrasting post-surgical evolution: M.D.M. still survives, while V.F. survived only for six months following first surgical intervention. The first patient, M.D.M., received chemotherapy before and after the surgery, which a slow but favorable recovery noted. For the second patient, the brain CT scan performed four months after surgery showed multiple masses in the cerebral posterior fossa, suggestive of leptomeningeal metastases, but without local recurrence of the medulloblastoma. The patient started chemotherapy and, after two sessions, she went for second surgical treatment. Six months after the second surgery, the second female patient, V.F., died. The objective of this study is to find the reasons of their different clinical evolution. The authors emphasized the clinical similarities of the patients, both being female, having similar symptoms and incidental medical events (upper and lower respiratory tract infections and head trauma) but most important, they stressed out the factors which contributed to the different clinical outcome, the second patient having a more aggressive form of medulloblastoma and receiving chemotherapy only after leptomeningeal metastases were evidenced. In addition, as for the second patient, she might had clinical criteria for type 1 neurofibromatosis (the author specified the number of the "café au lait" spots being over 6, like her brother, mental delay, without other clinical signs), which might have contributed to the poor outcome. The etiology of medulloblastoma can also be involved with chromosome 17 and the diagnosis of such a brain tumor can be an evolutive criterion for neurofibromatosis. The diagnosis can provided only by genetic tests. There is a vital risk and a reason for the lethal evolution of V.F. PATIENT: As medulloblastoma is a very aggressive malignant tumor, the approximate cumulative survival rate for preschool age group having a histological follow-up was found to be 47% over a span of five years of rigorous treatment.

Silencing of epidermal growth factor, latrophilin and seven transmembrane domain-containing protein 1 (ELTD1) via siRNA-induced cell death in glioblastoma.

The failure of therapies targeting tumor angiogenesis may be caused by anti-angiogenic resistance mechanisms induced by VEGF and non-VEGF pathways alterations. Anti-angiogenic therapy failure is also attributed to immune system, acting by tumor-associated macrophages that release pro-angiogenic factors and a consequent increase of blood vessels. Recently, in a study by Rheal et al., a new angiogenic receptor, epidermal growth factor, latrophilin, and 7 trans-membrane domain-containing protein 1 on chromosome 1(ELTD1) has been identified as a promising glioma biomarker. In this study we aim to analyse whether this receptor may be used as a target molecule in glioblastoma therapy. Our results showed that small interfering RNA silencing ELTD1 caused cytotoxicity in glioblastoma cells. We also found that PDGFR, VEGFR, and their common PI3K/mTOR intracellular pathway inactivation-induced cytotoxicity in glioblastoma cells. Further, we found high percent of cytotoxicity in a low passage glioblastoma cell line after BEZ235 (a dual inhibitor of PI3K/mTOR pathway) treatment at nanomolar concentrations, compared to AG1433 (a PDGFR inhibitor) and SU1498 (a VEGFR inhibitor) that were only cytotoxic at micromolar ranges. In the future, these could prove as attractive therapeutic targets in single therapy or coupled with classic therapeutic approaches such as chemotherapy of radiotherapy.

Dendritic cell immunotherapy versus bevacizumab plus irinotecan in recurrent malignant glioma patients: a survival gain analysis.

BACKGROUND: The bevacizumab and irinotecan protocol is considered a standard treatment regimen for recurrent malignant glioma. Recent advances in immunotherapy have hinted that vaccination with dendritic cells could become an alternative salvage therapy for the treatment of recurrent malignant glioma. METHODS: A search was performed on PubMed, Cochrane Library, Web of Science, ScienceDirect, and Embase in order to identify studies with patients receiving bevacizumab plus irinotecan or dendritic cell therapy for recurrent malignant gliomas. The data obtained from these studies were used to perform a systematic review and survival gain analysis. RESULTS: Fourteen clinical studies with patients receiving either bevacizumab plus irinotecan or dendritic cell vaccination were identified. Seven studies followed patients that received bevacizumab plus irinotecan (302 patients) and seven studies included patients that received dendritic cell immunotherapy (80 patients). For the patients who received bevacizumab plus irinotecan, the mean reported median overall survival was 7.5 (95% confidence interval [CI] 4.84-10.16) months. For the patients who received dendritic cell immunotherapy, the mean reported median overall survival was 17.9 (95% CI 11.34-24.46) months. For irinotecan + bevacizumab group, the mean survival gain was -0.02±2.00, while that for the dendritic cell immunotherapy group was -0.01±4.54. CONCLUSION: For patients with recurrent malignant gliomas, dendritic cell immunotherapy treatment does not have a significantly different effect when compared with bevacizumab and irinotecan in terms of survival gain (P=0.535) and does not improve weighted survival gain (P=0.620).

New perspectives in glioblastoma antiangiogenic therapy.

Glioblastoma (GB) is highly vascularised tumour, known to exhibit enhanced infiltrative potential. One of the characteristics of glioblastoma is microvascular proliferation surrounding necrotic areas, as a response to a hypoxic environment, which in turn increases the expression of angiogenic factors and their signalling pathways (RAS/RAF/ERK/MAPK pathway, PI3K/Akt signalling pathway and WTN signalling cascade). Currently, a small number of anti-angiogenic drugs, extending glioblastoma patients survival, are available for clinical use. Most medications are ineffective in clinical therapy of glioblastoma due to acquired malignant cells or intrinsic resistance, angiogenic receptors cross-activation and redundant intracellular signalling, or the inability of the drug to cross the blood-brain barrier and to reach its target in vivo. Researchers have also observed that GB tumours are different in many aspects, even when they derive from the same tissue, which is the reason for personalised therapy. An understanding of the molecular mechanisms regulating glioblastoma angiogenesis and invasion may be important in the future development of curative therapeutic approaches for the treatment of this devastating disease.

Targeting the VEGF and PDGF signaling pathway in glioblastoma treatment.

Growth factor receptors dysfunction has previously been correlated with glioma cell proliferation, ability to evade apoptosis, neo-angiogenesis and resistance to therapy. Antineoplastic molecules targeting growth factor receptors are in clinical handling, however the efficacy of these compounds has often been limited by the signaling redundancy. Here, we analyzed the effect of AG1433 (a PDGFR inhibitor), SU1498 (a VEGFR inhibitor) and BEZ235 (a PI3K/Akt/mTOR signaling pathways inhibitor) on glioblastoma cells in vitro. For this study, we used a low passage glioblastoma cell line (GB9B). Assessment of cell number over 72 h showed that the growth rate was 0.3024 and the doubling time of GB9B was 2.29 days. Similar cytotoxic effects were observed by using AG1433 and SU1498 treatment, while dual PI3K/Akt/mTOR inhibition by BEZ235 was more efficient in killing glioblastoma cells than individual PDGFR or VEGFR targeting. In SU1498 treated cells, caspase 3 activity was detected 3 hours after the treatment, while activation of caspase 8 and 9 was detected 48 hours later. AG1433 treatment induced caspase 3, 8 and 9, 3 hours after the treatment. BEZ235 treatment resulted in early caspase 3 and 8 activation, 3 hours after the treatment and an activation of caspase 9, 8 hours later.

Epidermal growth factor, latrophilin, and seven transmembrane domain-containing protein 1 marker, a novel angiogenesis marker.

Epidermal growth factor, latrophilin, and seven transmembrane domain-containing protein 1 on chromosome 1 (ELTD1), an orphan adhesion G-protein coupled receptor, was reported as a regulator of angiogenesis, also involved in cancer progression and development. More recently, ELTD1 was identified as a potential new tumor marker for high-grade glioma. ELTD1, belongs to the G-protein coupled receptor superfamily that comprises the biggest receptor family in the human genome. Following the discovery of ELTD1 almost a decade ago, only a few research groups have attempted to find its role in normal and tumor cells, important information about this receptor remaining still unknown. The ELTD1 ligand has not currently been identified and intracellular signaling studies have not yet been performed in normal or tumor cells. Although the current published data on ELTD1 function and structure are rather limited, this receptor seems to be very important, not only as biomarker, but also as molecular target in glioblastoma. This review summarizes and discusses the current knowledge on ELTD1 structure, function, and its role in both physiological and tumoral angiogenesis.

Inducible nitric oxide synthase expression (iNOS) in chronic viral hepatitis and its correlation with liver fibrosis.

BACKGROUND: Nitric oxide (NO) production by the action of the inducible nitric oxide synthase (iNOS or NOS2) is increased in tissues that are stimulated by cytokine and endotoxins. The role of NO in the pathogenesis of chronic viral hepatitis is not fully understood but it seems that its overproduction is responsible for the pathological changes under inflammatory conditions. AIM: In this paper, we analyzed the correlation between immunohistochemical expression of iNOS and liver fibrosis in chronic viral hepatitis. MATERIALS AND METHODS: Liver biopsies from patients diagnosed with chronic viral hepatitis B and C were embedded in paraffin and further used for histological staining and immunohistochemical reactions to detect the expression of iNOS and TGF-ß1. The degree of liver fibrosis was established using special staining (trichromic Masson and Gömöri's silver impregnation). RESULTS: In samples with low degree of fibrosis, we observed a discrete positivity for iNOS in periportal hepatocytes and the immunohistochemical reaction for TGF-ß1 were limited to the endothelial cells of liver sinusoids and pro-inflammatory cells from the portal tracts. Positive reaction for TGF-ß1 increased with the degree of liver fibrosis, while the expression of iNOS was enhanced in hepatocytes, as well as in bile ducts and endothelial cells. CONCLUSIONS: Infection with hepatitis B and C viruses induces iNOS expression in hepatocytes, suggesting that NO overproduction might have an important role in progression of chronic viral hepatitis to cirrhosis.

Cancer stem cells: biological functions and therapeutically targeting.

Almost all tumors are composed of a heterogeneous cell population, making them difficult to treat. A small cancer stem cell population with a low proliferation rate and a high tumorigenic potential is thought to be responsible for cancer development, metastasis and resistance to therapy. Stem cells were reported to be involved in both normal development and carcinogenesis, some molecular mechanisms being common in both processes. No less controversial, stem cells are considered to be important in treatment of malignant diseases both as targets and drug carriers. The efforts to understand the role of different signalling in cancer stem cells requires in depth knowledge about the mechanisms that control their self-renewal, differentiation and malignant potential. The aim of this paper is to discuss insights into cancer stem cells historical background and to provide a brief review of the new therapeutic strategies for targeting cancer stem cells.

Biobanking in a constantly developing medical world.

Biobank is a very sophisticated system that consists of a programmed storage of biological material and corresponding data. Biobanks are created to be used in medical research, in clinical and translational medicine, and in healthcare. In the past 20 years, a large number of biobanks have been set up around the world, to support the modern research directions in medicine such as omix and personalized medicine. More recently, embryonic and adult stem cell banks have been developed. Stem cell banking was reported to be required for medical research as well as clinical transplant applications. The quality of the samples stored in a biobank is very important. The standardization is also important; the biological material stored in a biobank must be processed in a manner that allows compatibility with other biobanks that preserve samples in the same field. In this paper, we review some issues related to biobanks purposes, quality, harmonization, and their financial and ethical aspects.

Tropomyosin-receptor-kinases signaling in the nervous system.

ABSTRACT: The development and function of the nervous system is dependent on many growth factors and their signaling. Tropomyosin-receptor-kinase receptor family controls synaptic strength and plasticity in the mammalian nervous system. Dysregulation of Tropomyosin-receptor-kinase receptors signaling can lead to neural developmental disorders and has been reported in certain diseases of the nervous system. Apart from their role in the nervous system, these tyrosine kinase receptors are also involved in cancer biology. Tropomyosin-receptor-kinases and their ligands, neurotrophins, are also involved in neural precursor stem cells differentiation. This review focuses on Tropomyosin-receptor-kinases, the most abundant receptors in mammalian nervous system.

Study of nimesulide release from solid pharmaceutical formulations in tween 80 solutions.

Nimesulide is a weakly acidic non-steroidal anti-inflammatory drug (NSAIDs). Like many non-steroidal anti-inflammatory drugs, Nimesulide is very sparingly soluble in water (≈ 0.01 mg/mL).The poor aqueous solubility and wettability of Nimesulide gives rise to difficulties in pharmaceutical formulations for oral or parenteral delivery, which may lead to variable bioavailability. Based on the Biopharmaceutical Classification System (BCS), Nimesulide is considered a BCS 2 drug (poorly soluble and highly permeable). Solubilization in surfactant solutions above critical micelle concentration (CMC) offers one approach to the formulation of poorly soluble drugs. Weakly acidic and basic drugs may be brought into solution by the solubilizing action of surfactants. In this study, different concentrations of Tween 80 was used in combination with buffer (pH 7.4) to increase the solubility of Nimesulide. The results show that the dependence of the released amount on the Tween concentration is not linear, very low Tween concentration showing a decrease of "solubility", probably connected to a critical micelle concentration at the interface Nimesulide solution. An "analytical" artefact connected to a decreasing ultraviolet absorption of Nimesulide because of Nimesulide precipitation, the formation of a colloidal solution is possible, and the phenomenon remains to be searched further. It is hard to explain that for an almost complete solubilization a significant Tween quantity is necessary and this should be more than that of other slightly soluble drugs.