Bioconjugate-loaded solid lipid nanoparticles for enhanced anticancer drug delivery to brain cancer cells: An in vitro evaluation

Background & objectives: The treatment of brain cancer is still challenging for an oncologist due to the presence of the blood-brain barrier (BBB) which inhibits the entry of more than 98 per cent of drugs used during the treatment of brain disease. The cytotoxic drugs used in chemotherapy for brain cancer treatment also affect the normal cells due to lack of targeting. Therefore, the objective of the study was to develop tween 80-coated solid lipid nanoparticles (SLNs) loaded with folic acid-doxorubicin (FAD) conjugate for site-specific drug delivery to brain cancer cells. Methods: The FAD conjugate was synthesized by the conjugation of folic acid with doxorubicin and characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. SLNs loaded with FAD were prepared by the solvent injection method. The SLNs were characterized by the particle size, zeta potential, surface morphology, entrapment efficiency, etc. Results: The average particle size of FAD conjugate-loaded SLNs (SLN-C) was found to be 220.4±2.2 nm, with 36.2±0.6 per cent entrapment efficiency. The cytotoxicity and cellular uptake were determined on U87 MG cell lines. Half maximal inhibitory concentration value of the SLN-C was found to be 2.5 ?g/ml, which confirmed the high antitumour activity against brain cancer cells. Interpretation & conclusions: The cell line studies confirmed the cytotoxicity and internalization of SLN-C in U87 MG brain cancer cells. The results confirmed that tween 80-coated SLNs have the potential to deliver the doxorubicin selectively in the brain cancer cells.

Mild overexpression of a novel transcription factor Grainy head like-2 (Grhl2) elicits hybrid phenotype in human astrocytoma cells

The Grainy head like-2 (Grhl2) transcription factor plays a major role in embryonic and cancer development. The role of Grhl2 has been intensively studied in various cancers but not for brain cancer. Hence, in this study, we provide a preliminary understanding on the role of Grhl2 that regulate the transition of astrocytoma cells. The human A172 astrocytoma cell line, a mesenchymal cell characterized by mild overexpression of Grhl2 transcription factor, was used in this study. At first, the Grhl2 stably overexpressing A172 clones into three types i.e., Grhl2+ (mild), Grhl2++ (moderate) and Grhl2+++ (high) based on mRNA and protein expression levels of Grhl2 were characterized. Phenotypic characteristics of vector and Grhl2+ cells were observed using phase contrast microscopy. Quantitative PCR (qPCR), Western blot and immunofluorescence were used to detect the level of mesenchymal markers (N-cadherin/vimentin) and also epithelial markers (E-cadherin/ ?- catenin) in vector and Grhl2+ cells. The migration and invasion characteristics of vector and Grhl2+ cells were determined by scratch assay and Boyden chamber assay. Further, the Grhl2+ cells were characterized to determine the effect of temozolomide chemotherapy drug which were widely used in treating brain cancer. As expected, in phase contrast image, we observed the mesenchymal characteristic of A172 cells becomes hybrid phenotype i.e., mixture of mesenchymal (spindle-like fibroblast morphology) and epithelial (cobblestone like appearance) cells upon Grhl2 mild expression (Grhl2+) when compared to vector cells. Further, we found that there was a significant upregulation of E-cadherin at both mRNA and protein levels in Grhl2+ cells when compared to vector cells. There was a significant upregulation of ?-catenin, N-cadherin and vimentin at mRNA levels, but there was no significant upregulation at the protein levels in Grhl2+ cells compared to the vector cells. The migration and invasion were diminished in Grhl2+ cells when compared to the vector control cells. We observed that the Grhl2+ were sensitive to the temozolomide compared to the vector cells. This infers that the Grhl2+ cells were unable to attain complete transition of mesenchymal to epithelial state, and hence we categorized the Grhl2+ cells as hybrid phenotype. The results provide a better understanding of the largely unknown function of Grhl2 in human astrocytoma cells as tumor progression or suppression.

Matteucinol combined with temozolomide inhibits glioblastoma proliferation, invasion, and progression: an in vitro, in silico, and in vivo study

Glioblastoma is the most prevalent and malignant brain tumor identified in adults. Surgical resection followed by radiotherapy and chemotherapy, mainly with temozolomide (TMZ), is the chosen treatment for this type of tumor. However, the average survival of patients is around 15 months. Novel approaches to glioblastoma treatment are greatly needed. Here, we aimed to investigate the anti-glioblastoma effect of the combination of matteucinol (Mat) (dihydroxyflavanone derived from Miconia chamissois Naudin) with the chemotherapeutic TMZ in vitro using tumor (U-251MG) and normal astrocyte (NHA) cell lines and in vivo using the chick embryo chorioallantoic membrane (CAM) assay. The combination was cytotoxic and selective for tumor cells (28 μg/mL Mat and 9.71 μg/mL TMZ). Additionally, the combination did not alter cell adhesion but caused morphological changes characteristic of apoptosis in vitro. Notably, the combination was also able to reduce tumor growth in the chick embryo model (CAM assay). The docking results showed that Mat was the best ligand to the cell death membrane receptor TNFR1 and to TNFR1/TMZ complex, suggesting that these two molecules may be working together increasing their potential. In conclusion, Mat-TMZ can be a good candidate for pharmacokinetic studies in view of clinical use for the treatment of glioblastoma.

Therapeutic Interventions in Adult Low-Grade Gliomas

Treating adult low-grade gliomas (LGGs) is particularly challenging due to the highly infiltrative nature of this type of brain cancer. Although surgery, radiotherapy, and chemotherapy are the mainstay treatment modalities for LGGs, the optimal combination management plan for a particular patient based on individual symptoms and the risk of treatment-induced toxicity remains unclear. This review highlights the competency and limitations of standard treatment options while providing an essential therapeutic update regarding current clinical trials aimed at implementing targeted therapies with morbidity rates lower than those for current LGG treatments and also augmenting the killing of cancerous cells while maintaining an improved quality of life.

Indications of 5-Aminolevulinic Acid and Intraoperative MRI in Glioma Surgery: First Cases in Latin America in a Single Reference Center

Introduction The improvement on the extent of resection (EOR) of gliomas with the combination of 5-aminolevulinic acid (5-ALA) and intraoperative magnetic resonance imaging (iMRI) has been demonstrated in previous studies. We present our results with the combined use of 5-ALA and (iMRI) in the surgery of glial lesions. Methods A total of 64 cases of patients with intracranial gliomas who underwent image-guided surgery using 5-ALA with and without (iMRI) were reviewed. All patients underwent an early postoperative MRI to evaluate the EOR. Other intra-operative techniques (awake surgery, electrophysiological stimulation and monitoring) were also performed according to the location of the tumor. Results A total of 18 tumors did not show intraoperative 5-ALA fluorescence (according to the World Health Organization [WHO] classification of tumors, 2 WHO-grade I, 14 WHOgrade II, 1 WHO-grade III and 1 WHO-grade IV), and 46 tumors showed intraoperative 5-ALA fluorescence (3 WHO-grade II, 3 WHO-grade III, 40 WHO-grade IV). In 28 of the 46 5-ALA positive cases, a safe 5-ALA free resection was achieved. In the 5-ALA negative cases, the (iMRI) findings guided the EOR, and complete resection was achieved in 11 cases. Complete resection was opted out in gliomas infiltrating eloquent areas. Conclusions The combined use of 5-ALA and IMRI showed improved results in glioma surgery, offering the safest maximal EOR. In the 5-ALA positive cases (mostly highgrade), fluorescence was a more useful tool. In the 5- ALA negative cases (mostly lowgrade), the (iMRI) was decisive to guide the EOR of the tumor.

Introdução Em estudos anteriores, foi demonstrado um aperfeiçoamento na extensão da resecção (EDR) de gliomas com a combinação de ácido 5-aminolevulínico (5-ALA) e a imagem de ressonância magnética intraoperatória (iRM). Nossos resultados são apresentados com o uso combinado de 5-ALA e (iRM) para a cirurgia de lesões gliais. Métodos Foram revisados 64 casos de gliomas intracranianos submetidos a cirurgia guiada por imagem por meio do uso de 5-ALA, com ou sem RMI. Todos os pacientes foram submetidos a ressonância magnética (RM) pré-operatória para a avaliação da EDR do tumor. Outras técnicas intraoperatórias (cirurgia acordado, estimulação eletrofisiológica e monitoração) também foram realizadas segundo a localização do tumor. Resultados Um total de 18 tumores não apresentaram fluorescência com o 5-ALA (segundo a classificação de tumores da Organização Mundial de Saúde [OMS], 2 com grau OMS I, 14 com grau II, 1 com grau III e 1 com grau IV) e 46 tumores foram fluorescentes (3 com grau II, 3 com grau III, 40 com grau IV). Dos 46 casos positivos para 5-ALA, em 28 foi obtida uma ressecção segura e livre. Nos casos negativos para 5-ALA, os achados da (iRM) orientaram a EDR, e alcançou-se ressecção total em 11 casos. A ressecção total foi descartada em gliomas com infiltração em áreas eloquentes. Conclusões O uso combinado de 5-ALA e (iRM) mostrou melhores resultados na cirurgia de gliomas, oferecendo uma EDR de segurança máxima. Nos casos positivos para 5-ALA (a maioria de grau alto), a fluorescência mostrou-se um instrumento mais útil. Nos casos negativos para 5-ALA (a maioria de grau baixo), a RMI foi decisiva para orientar a EDR tumoral.

Adult mortality from leukemia, brain cancer, amyotrophic lateral sclerosis and magnetic fields from power lines: a case-control study in Brazil / Mortalidade por leucemia, câncer de cérebro e esclerose lateral amiotrófica em relação a campos magnéticos: estudo do tipo caso-controle no Brasil

Recent publications renewed interest in assessing potential health risks for subjects living close to transmission lines. This study aimed at evaluating the association of both distance of home address to the nearest overhead transmission line and of the calculated magnetic fields from the power lines and mortality from leukemia, brain cancer, and amyotrophic lateral sclerosis. We carried out a death certificate based case-control study accessing adult mortality in the Metropolitan Region of São Paulo, in Brazil. Analysis included 1,857 cases of leukemia, 2,357 of brain cancer, 367 of amyotrophic lateral sclerosis, and 4,706 as controls. An increased risk for mortality from leukemia among adults living at closer distances to transmission lines compared to those living further then 400 m was found. Risk was higher for subjects that lived within 50 m from power lines (OR=1.47; 95 percent CI=0.99-2.18). Similarly, a small increase in leukemia mortality was observed among adults living in houses with higher calculated magnetic fields (OR=1.61; 95 percent CI=0.91-2.86 for those exposed to magnetic fields >0.3 µT). No increase was seen for brain tumours or amyotrophic lateral sclerosis. Our findings are suggestive of a higher risk for leukemia among subjects living closer to transmission lines, and for those living at homes with higher calculated magnetic fields, although the risk was limited to lower voltage lines.

Os estudos avaliando riscos à saúde da exposição a campos magnéticos têm apresentado resultados controversos. Duas revisões recentes apontam a necessidade de mais investigações sobre o tema. O objetivo deste trabalho foi avaliar o risco de mortalidade por leucemia, câncer de cérebro e esclerose lateral amiotrófica em adultos em relação à exposição residencial a campos magnéticos gerados por linhas de transmissão. Foi realizado um estudo do tipo caso-controle de base populacional utilizando dados do sistema de informação de mortalidade na Região Metropolitana de São Paulo, entre 2001 e 2005. O risco foi avaliado em relação à distância das residências para as linhas de transmissão e para o campo magnético calculado em cada residência. Foram incluídos no estudo 1.857 casos de leucemia, 2.357 de câncer de cérebro e 367 de esclerose lateral amiotrófica, além de 4.706 controles. Encontrou-se um risco aumentado para leucemia em adultos morando mais perto das linhas de transmissão em comparação àqueles morando a mais do que 400 m. O maior risco foi entre os que moravam a até 50 m da linha (OR=1,47; IC95 por cento=0,99-2,18). Também foi encontrado risco para pessoas morando em casas expostas ao maior campo magnético (OR=1,61; IC95 por cento=0,91-2,86, para campos magnéticos >0,3 µT). Não foi encontrado aumento para tumores cerebrais ou esclerose lateral amiotrófica. Nenhum dos resultados foi estatisticamente significante. Os resultados sugerem aumento no risco de mortalidade por leucemia entre adultos expostos a campos magnéticos, mas os resultados devem ser interpretados com cautela, uma vez que todos os intervalos de 95 por cento confiança englobavam o risco nulo.

Fatores da dieta e tumores de cérebro / Dietary factors and brain tumors / Factores dietéticos y los tumores cerebrales

As hipóteses sobre a associação entre fatores da dieta e tumores de cérebro relacionam-se aos compostos N-nitroso como favorecedores do desenvolvimento desses tumores e ao papel de antioxidantes dietéticos atuando como protetores, através da inibição da nitrosação dos precursores dos compostos N -nitroso. O objetivo deste artigo é identificar fatores da dieta associados aos tumores primários de cérebro em indivíduos adultos (??20 anos). Trata-se de um estudo caso-controle de base populacional, realizado na Região Metropolitana de Salvador, estado da Bahia, Brasil. Foram realizadas análises de regressão logística para a estimativa das razões de chances ajustadas e respectivos intervalos de confiança a 95 porcento. Os resultados apontam uma associação inversa para o maior consumo de laticínios (OR igual 0,32; 95 porcento IC: 0,13 ? 0,80) e vitamina C (OR igual 0,34; 95 porcento IC: 0,13 ? 0,88) para todos os tumores de cérebro agrupados. Para os tumores não-astrocíticos o maior consumo de refrigerantes (OR igual 0,20; 95 porcento IC: 0,06 ? 0,63) demonstrou efeito protetor. Conclui-se que os fatores da dieta podem atuar de forma diferente entre os tumores de cérebro; o efeito protetor das vitaminas antioxidantes, especialmente a vitamina C, sugere que o maior consumo de legumes e frutas pode diminuir o risco para o desenvolvimento desses tumores.

The hypotheses about the association between dietary factors and brain tumors are related to N-nitroso compounds as promoters of development of these tumors and the role of dietary antioxidants acting as guards, through the inhibition of nitrosation of precursors of N-nitroso compounds.The aim of this paper is to identify dietary factors associated with primary brain tumors in adults (??20 years). This is a population-based case-control study conducted in the metropolitan area of Salvador,Bahia, Brazil. Logistic regression estimated adjusted odds ratios and confidence intervals at 95percent. Theresults indicate an inverse association for the highest intake of dairy products (OR equal 0.32, 95 percent CI: 0.13 - 0.80) and vitamin C (OR equal 0.34, 95 percent CI: 0.13 to 0.88) for all grouped brain tumors. For nonastrocytic tumors, the highest consumption of soft drinks (OR equal 0.20, 95 percent CI: 0.06 to 0.63) demonstrated a protective effect. It was concluded that dietary factors may act differently among brain tumors; the protective effect of antioxidant vitamins, especially vitamin C, suggests that a higher consumption of vegetables and fruits can reduce the risk of developing these tumors.

Las hipótesis sobre la asociación entre factores dietéticos y los tumores cerebrales están relacionadas con los compuestos N-nitroso como promotores del desarrollo de estos tumores y el papel de los antioxidantes dietéticos en calidad de protectores, a través de la inhibición de la nitrosación de los precursores de compuestos N-nitroso. El objetivo de este artículo es identificar los factores de la dieta asociados a los tumores primarios de cerebro en individuos adultos (??20 años). Se trata de un estudio caso-control de base en la población, llevado a cabo en el área metropolitana de Salvador, Bahia, Brasil. Se analizaron análisis mediante regresión logística para estimar razones de posibilidades ajustadas y los respectivos intervalos de confianza al 95 por ciento. Los resultados indican una asociación inversa para el mayor consumo de productos lácteos (OR igual 0,32, IC 95 por ciento: 0,13 a 0,80) y vitamina C (OR igual 0,34, IC 95por ciento: 0,13 a 0,88) de todos los tumores cerebrales agrupados. Para los tumores no Astrocíticos, el mayor consumo de refrescos (OR igual 0,20, IC 95 por ciento: 0,06 a 0,63) demostró un efecto protector. Se concluyó que los factores dietéticos pueden actuar de forma diferente entre los tumores cerebrales; el efecto protector de las vitaminas antioxidantes, especialmente vitamina C, sugiere que um mayor consumo de legumbres y frutas puede disminuir el riesgo de desarrollar estos tumores.

Current Status of Immunotherapeutic Strategies for Central Nervous System Tumors

Malignant gliomas are the most common type of primary brain tumor and are in great need of novel therapeutic approaches. Advances in treatment have been very modest, significant improvement in survival has been lacking for many decades, and prognosis remains dismal. Despite "gross total" surgical resections and currently available radio-chemotherapy, malignant gliomas inevitably recur due to reservoirs of notoriously invasive tumor cells that infiltrate adjacent and non-adjacent areas of normal brain parenchyma. In principle, the immune system is uniquely qualified to recognize and target these infiltrative pockets of tumors cells, which have generally eluded conventional treatment approaches. In the span of the last 10 years, our understanding of the cancer-immune system relationship has increased exponentially; and yet we are only beginning to tease apart the intricacies of the central nervous system and immune cell interactions. This article reviews the complex associations of the immune system with brain tumors. We provide an overview of currently available treatment options for malignant gliomas, existing gaps in our knowledge of brain tumor immunology, and strategies that might be exploited for improved design of "custom immunotherapeutics." We will also examine major new immunotherapy approaches that are being actively investigated to treat patients with malignant glioma, and identify some current and future research priorities in this area.

Cancer Incidence in the Vicinity of Korean AM Radio Broadcast Towers / 대한산업의학회지

OBJECTIVES: Several studies have raised the possibility that exposure to electrical and/or magnetic fields may be particularly harmful in the promotion or initiation of cancer. The purpose of this study which was based on a geographical correlation design was to investigate any association that may exist between residing near radio broadcast towers and carcinogenic activity in Korea. METHODS: In this study, the health effects of EMF of 10 AM radio broadcast towers in Korea were investigated. The electric powers of the towers were above 100kW. We chose exposed areas that were located within 2 km from the towers as well as four control regions which had similar populations in the same province(Do) but had no towers nearby. The incidence of leukemia, malignant lymphoma, brain tumor and breast cancer between the exposed areas and the control areas was compared. The standardized incidence ratios(SIRs) were calculated. Korean Medical Insurance data(between Nov,1,1993 and Oct,31,1996) was used for the cancer incidence estimation. The Nationwide Population Census data(in 1995) and the Resident Register data(in 1995) were used for information about population and locations. RESULTS: Among the 10 exposed areas, one area for leukemia and one area for brain tumor showed a significantly high incidence compared to the control areas. There were no significant increased areas for malignant lymphoma and breast cancer. CONCLUSIONS: This study design must be considered to be exploratory and not used for determining causality. However, the results suggest the necessity for further analytical epidemiological studies that have a more precise exposure measurement scale and information on confounding factors.