A Comparison of MGMT Testing by MSP and qMSP in Paired Snap-Frozen and Formalin-Fixed Paraffin-Embedded Gliomas

Comparative analysis of the conventional methylation-specific PCR (MSP) vs. the quantitative MSP (qMSP) assessment of the O⁶-methylguanine-DNA methyltransferase (MGMT) promoter methylation status in 34 snap-frozen (SF) glioma samples was performed. The accuracy of the semi-quantitative MSP was compared with the corresponding qMSP semi-quantitative values using two semi-quantitative cut-off values (0-unmethylated and 1-weakly methylated) to discriminate methylated from unmethylated samples. In the case of the cut-off value 0, MSP test showed 80.0% sensitivity and 78.9% specificity compared to the reference qMSP analysis. However, when using the cut-off value 1, the diagnostic accuracy of the MSP test was significantly higher (85.7% sensitivity, 85.2% specificity). Fleiss' Kappa statistical analyses indicated moderate agreement (Fleiss' Kappa Coefficient = 0.509; 70.59% agreement) between MSP and qMSP semi-quantitative measurements of MGMT promoter methylation in glioma patients, justifying the conventional MSP use in diagnostics and confirming its high reliability. Further, we aimed to compare the validity of SF and formalin-fixed paraffin-embedded (FFPE) glioma samples for MGMT testing. Statistical analyses indicated moderate overall agreement of FFPE glioma samples and SF MSP semi-quantitative measurements (Fleiss' Kappa Coefficient = 0.516/0.509; 70.0% agreement) and emphasized their low reliability in the assessment of highly methylated MGMT promoter samples.

The Significance of MGMT Promoter Methylation Status in Diffuse Glioma

A single-institution observational study with 43 newly diagnosed diffuse gliomas defined the isocitrate dehydrogenase 1 and 2 (IDH1/2) gene mutation status and evaluated the prognostic relevance of the methylation status of the epigenetic marker O6-methylguanine-DNA methyltransferase (MGMT). Younger patients (<50 years) with surgically resected glioma and temozolomide (TMZ) adjuvant chemotherapy were associated with better prognosis, consistent with other studies. The methylation status depends on the chosen method and the cut-off value determination. Methylation-specific PCR (MSP) established the methylation status for 36 glioma patients (19 (52.8%) positively methylated and 17 (47.2%) unmethylated) without relevancy for the overall survival (OS) (p = 0.33). On the other side, real-time methylation-specific PCR (qMSP) revealed 23 tumor samples (54%) that were positively methylated without association with OS (p = 0.15). A combined MSP analysis, which included the homogenous cohort of 24 patients (>50 years with surgical resection and IDH1/2-wildtype diffuse glioma), distinguished 10 (41.6%) methylated samples from 14 (58.4%) unmethylated samples. Finally, significant correlation between OS and methylation status was noticed (p ≈ 0.05). The OS of the hypermethylated group was 9.6 ± 1.77 months, whereas the OS of the unmethylated group was 5.43 ± 1.04 months. Our study recognized the MGMT promoter methylation status as a positive prognostic factor within the described homogenous cohort, although further verification in a larger population of diffuse gliomas is required.

Antioxidant Activity of Hemp (Cannabis sativa L.) Seed Oil in Drosophila melanogaster Larvae under Non-Stress and H2O2-Induced Oxidative Stress Conditions

The oil extracted from hemp seeds has significant nutritional and biological properties due to the unique composition of polyunsaturated fatty acids and various antioxidant compounds. The potential of this oil for the prevention of oxidative stress and for the treatment of oxidative-stress-induced ailments is of increasing interest. Most studies of hemp seed oil were conducted in-vitro, meaning we lack information about effects and activity in vivo. In the present study, we evaluated the hypothesis that hemp seed oil at different concentrations improves the oxidative state of D. melanogaster, under non-stress as well as hydrogen-peroxide-induced stress. We analyzed the effects of hemp seed oil on oxidative stress markers and on the life cycle of D.melanogaster under non-stress and hydrogen-peroxide-induced stress conditions. D.melanogaster larvae were exposed to hemp seed oil concentrations ranging from 12.5 to 125 μL/mL. The results revealed that under non-stress conditions, oil concentrations up to 62.5 µL/mL did not induce negative effects on the life cycle of D. melanogaster and maintained the redox status of the larval cells at similar levels to the control level. Under oxidative stress conditions, biochemical parameters were significantly affected and only two oil concentrations, 18.7 and 31.2 µL/mL, provided protection against hydrogen peroxide stress effects. A higher oil concentration (125 μL/mL) exerted negative effects on the oxidative status and increased larval mortality. The tested oil was characterized chemically by NMR, transesterification, and silylation, followed by GC-MS analyses, and was shown to contain polyunsaturated fatty acid triglycerides and low levels of tocopherols. The high levels of linoleic and linolenic acids in the oil are suggested to be responsible for the observed in vivo antioxidant effects. Taken together, the results show that hemp seed oil is effective for reducing oxidative stress at the cellular level, thus supporting the hypothesis. The obtained results point to the potential of hemp seed oil for the prevention and treatment of conditions caused by the action of reactive oxygen species.

Changes in the wing shape and size in Drosophila melanogaster treated with food grade titanium dioxide nanoparticles (E171) - A multigenerational study

Drosophila is among the most commonly used models for toxicity assessment of different types of nanoparticles. This study aims to examine the effects of a constant exposure to the low concentration of human food grade titanium dioxide nanoparticles (TiO₂ E171) on Drosophila melanogaster wing morphology over multiple generations. Subsequently, the Geometric Morphometrics Analysis was employed to examine possible changes in the wing shape and size of the treated flies. The treatment resulted in the diminishment but not a disruption in the sexual dimorphism in wings. Consequently, the female flies were clearly separated from the male flies by the differences in wing morphology as in the control group. A splitting by generations was overly similar within the control and the treatment, but it was slightly more pronounced in the treatment. However, the observed generational differences seemed mostly random between generations, irrespective of the treatment. Specifically, the treated groups displayed slightly higher splitting by generations in females than in males. Regardless of the generation, the results show a clear splitting by the differences in the wing shape between the treated flies and the flies from control. The mean value of centroid size, which refers to the wing size, of both female and male wings was smaller in the treatment when compared to the control. The overall effect of TiO₂ was to induce significant difference in Drosophila wing morphology but it did not alter the general wing morphology pattern. Therefore, the change in the wings occurred only within the normally allowed wing variation.

Atmospheric Plasma Supported by TiO2 Catalyst for Decolourisation of Reactive Orange 16 Dye in Water

PURPOSE

Every advanced oxidation process (AOP) has its limitations in water purification. Novel designs with simultaneous application of different AOPs can offer better solutions for cleaner water.

METHODS

We have comparatively studied two advanced oxidation processes (AOPs) on decolourisation of Reactive Orange 16 (RO 16) azo dye pollutant from water: gas plasma treatment by low power atmospheric pressure plasma using novel plasma needle configuration, and semiconductor heterogeneous photocatalysis using titanium dioxide (TiO₂) nanopowders. Additionally, simultaneous application of two advanced oxidation processes on azo dye decolourisation was studied.

RESULTS

It was found that plasma treatment is very efficient system for the dye removal even for low flow rates (1 slm) of the Ar as feed gas. The presence of 10% of O₂ in Ar flow intensified dye oxidation process and shortened required time for total decolourisation. When plasma and catalyst were simultaneously applied, TiO₂ was activated with a few Watts plasma source as well as 300 W UV lamp source. The synergic effect of two AOPs was more pronounced for higher feed gas flow rates, resulting in improved decolourisation efficiency.

CONCLUSION

Plasma needle can efficiently remove Reactive Orange 16 azo dye from water with a power consumption of only few Watts. With the addition of TiO₂ the removal efficiency is significantly improved.

Non-thermal plasma needle as an effective tool in dimethoate removal from water

Intensive use of pesticides requires innovative approaches for their removal from the environment. Here we report the method for degradation of dimethoate in water using non-thermal plasma needle and analyze kinetics of dimethoate removal and possible degradation pathways. The effects of dimethoate initial concentration, plasma treatment time, Argon flow rate and the presence of radical promoters on the effectiveness of proposed method are evaluated. With argon flow rate of 0.5 slm (standard litres per minute) 1 × 10^-4 M dimethoate can be removed within 30 min of treatment. Using UPLC analysis it was confirmed that one of the decomposition products is dimethoate oxo-analogue omethoate, which is in fact more toxic than dimethoate. However, the overall toxicity of contaminated water was reduced upon the treatment. The addition of H₂O₂ as a free radical promoter enhances dimethoate removal, while K₂S₂O₈ results with selective conversion to omethoate. Using mass spectrometry in combination with the theoretical calculations, possible degradation pathways were proposed. The feasibility of the proposed method for dimethoate degradation in real water samples is confirmed. The proposed method is demonstrated as a highly effective approach for dimethoate removal without significant accumulation of undesirable toxic products and secondary waste.

Virtual water quality monitoring at inactive monitoring sites using Monte Carlo optimized artificial neural networks: A case study of Danube River (Serbia)

Rationalization of water quality monitoring stations nowadays is applied in many countries. In some cases, missing data from abandoned/inactive stations, spatial and temporal, could be very important, hence the use of artificial neural networks (ANNs) for virtual water quality monitoring at inactive monitoring sites was investigated. The aim was to develop single-output and simultaneous ANNs for the spatial interpolation of 18 water quality parameters at single- and multi-inactive monitoring sites on Danube River course through Serbia. Those different modeling approaches were considered in order to determine the most suitable combination of models. The variable selection and sensitivity analysis in the case of simultaneous models were performed using a modified procedure based on Monte Carlo Simulations (MCS). In general, the multi-target models tend to be more accurate than single target ones, while single output models outperform the simultaneous ones. Hence, for particular monitoring network and set of water quality parameters the optimal combination of models must be defined based on model's accuracy and computational effort needed. The MCS selection procedure has proved to be efficient only in the case of simultaneous multi-target model. MCS based analysis of input-output interactions has shown all significant interactions in the case of simultaneous single-target are grouped as a complex cluster of interactions, where majority of inputs influence on several outputs. In the case multi-target model those interactions were portioned in five separate clusters, there majority of them mimic the input-output interactions that are present in single output models. The modeling strategy for study area was proposed on the basis of the performance of created models (mean average percentage error < 10%): simultaneous multi-target model for pH, alkalinity, conductivity, hardness, dissolved oxygen, HCO₃^-, SO₄^2- and Ca, single-output multi-target models for temperature and Cl^-, simultaneous single-target models for Mg and CO₂, single output single target models for NO₃^-.

The Impact of MGMT Promoter Methylation and Temozolomide Treatment in Serbian Patients with Primary Glioblastoma

Background and objective: Despite recent advances in treatment, glioblastoma (GBM) remains the most lethal and aggressive brain tumor. A continuous search for a reliable molecular marker establishes the methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) gene promoter as a key prognostic factor in primary glioblastoma. The aim of our study was to screen Serbian patients with primary glioblastoma for an MGMT promoter hypermethylation and to evaluate its associations with overall survival (OS) and sensitivity to temozolomide (TMZ) treatment. Materials and methods: A cohort of 30 Serbian primary glioblastoma patients treated with radiation therapy and chemotherapy were analyzed for MGMT promoter methylation and correlated with clinical data. Results: MGMT methylation status was determined in 25 out of 30 primary glioblastomas by methylation-specific PCR (MSP). MGMT promoter hypermethylation was detected in 12 out of 25 patients (48%). The level of MGMT promoter methylation did not correlate with patients' gender (p = 0.409), age (p = 0.536), and OS (p = 0.394). Treatment with TMZ significantly prolonged the median survival of a patient (from 5 to 15 months; p < 0.001). Conclusions: Due to a small cohort of primary GBM patients, our study is not sufficient for definitive conclusions regarding the prognostic value of MGMT methylation for the Serbian population. Our preliminary data suggest a lack of association between MGMT promoter methylation and overall survival and a significant correlation of TMZ treatment with overall survival. Further population-based studies are needed to assess the prognostic value of the MGMT promoter methylation status for patients with primary glioblastoma.

The impact of concentration and administration time on the radiomodulating properties of undecylprodigiosin in vitro

Undecylprodigiosin pigment (UPP) is reported to display cytotoxic activity towards various types of tumours. Nevertheless, its efficacy in modifying the cellular response to ionising radiation is still unknown. In this study, the radiomodulating effects of UPP were investigated. The effects of UPP were assessed in vitro by treating cultures of human peripheral blood with UPP and ionising radiation using two treatment regimens, the UPP pre-irradiation treatment and UPP post-irradiation treatment. The activity of UPP was investigated evaluating its effects on the radiation-induced micronuclei formation, cell proliferation, and induction of apoptosis. The redox modulating effects of UPP were examined measuring the catalase activity and the level of malondialdehyde, as a measure of oxidative stress. The results showed that UPP effects on cellular response to ionising radiation depend on its concentration and the timing of its administration. At low concentration, the UPP displayed radioprotective effects in γ-irradiated human lymphocytes while at higher concentrations, it acted as a radiosensitiser enhancing either mitotic catastrophe or apoptosis depending on the treatment regimen. The UPP modified redox processes in cells, particularly when it was employed prior to γ-irradiation. Our data highlight the importance of further research of the potential of UPP to sensitize tumour cells to radiation therapy by inhibiting pathways that lead to treatment resistance.

Biological effects of bacterial pigment undecylprodigiosin on human blood cells treated with atmospheric gas plasma in vitro

It is known that some bacterial species are more resilient to different kinds of irradiation due to the naturally developed protective mechanisms and compounds such as pigments. On the other hand, reasoned tissue engineering using plasma remains a critical task and requires very precise control of plasma parameters in order to mitigate its potential detrimental effects. Here we isolated a natural protective agent, microbially produced undecylprodigiosin ((5'Z)-4'-methoxy-5'-[(5-undecyl-1H-pyrrol-2-yl)methylene]-1H,5'H-2,2'-bipyrrole), and investigated its effects on human blood cells independently and in combination with plasma. Two approaches were applied; the first, undecylprodigiosin (UP pigment) was added to the blood cultures, which then were exposed to plasma (pre-treatment); and the second- the blood cultures were exposed to plasma and then treated with pigment (post-treatment). The interactions of plasma and UP pigment with blood cells were investigated by conducting a series of biological tests providing the information regarding their genotoxicity, cytotoxicity and redox modulating activities. The exposure of cells to plasma induced oxidative stress as well as certain genotoxic and cytotoxic effects seen as elevated micronuclei incidence, decreased cell proliferation and enhanced apoptosis. In blood cultures treated with UP pigment alone, we found that both cytotoxic and protective effects could be induced depending on the concentration used. The highest UP pigment concentration increased lipid peroxidation and the incidence of micronuclei by more than 70% with maximal suppression of cell proliferation. On the contrary, we found that the lowest UP pigment concentration displayed protective effects. In combined treatments with plasma and UP pigment, we found that UP pigment could provide spatial shielding to plasma exposure. In the pre-treatment approach, the incidence of micronuclei was reduced by 35.52% compared to control while malondialdehyde level decreased by 36% indicating a significant mitigation of membrane damage induced by plasma. These results open perspectives for utilizing UP pigment for protection against overexposures in the field of plasma medicine.

Antioxidant, antimicrobial and antiproliferative activities of five lichen species

The antioxidative, antimicrobial and antiproliferative potentials of the methanol extracts of the lichen species Parmelia sulcata, Flavoparmelia caperata, Evernia prunastri, Hypogymnia physodes and Cladonia foliacea were evaluated. The total phenolic content of the tested extracts varied from 78.12 to 141.59 mg of gallic acid equivalent (GA)/g of extract and the total flavonoid content from 20.14 to 44.43 mg of rutin equivalent (Ru)/g of extract. The antioxidant capacities of the lichen extracts were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging. Hypogymnia physodes with the highest phenolic content showed the strongest DPPH radical scavenging effect. Further, the antimicrobial potential of the lichen extracts was determined by a microdilution method on 29 microorganisms, including 15 strains of bacteria, 10 species of filamentous fungi and 4 yeast species. A high antimicrobial activity of all the tested extracts was observed with more potent inhibitory effects on the growth of Gram (+) bacteria. The highest antimicrobial activity among lichens was demonstrated by Hypogymnia physodes and Cladonia foliacea. Finally, the antiproliferative activity of the lichen extracts was explored on the colon cancer adenocarcinoma cell line HCT-116 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) viability assay and acridine orange/ethidium bromide staining. The methanol extracts of Hypogymnia physodes and Cladonia foliacea showed a better cytotoxic activity than the other extracts. All lichen species showed the ability to induce apoptosis of HCT-116 cells.

Gene therapy of cancer

The original concept of gene therapy was the introduction of a healthy copy of gene into an ill human cell in order to correct gene defects in monogenic hereditary diseases. Since then the idea of gene therapy was expanded to cure or slow down the progression of numerous inherited and acquired diseases. Presently, there are 918 ongoing gene therapy clinical trials worldwide. The major indication in these trials is cancer (608 trials or 66% of the total number). Gene therapy of cancer can be defined as transfer of nucleic acids into tumor or normal cells aiming at eradicating or reducing the tumor mass by direct killing of cells, immunomodulation or correction of genetic errors and reversion of the malignant status. Initially started with lots of optimism and enthusiasm, cancer genet therapy has shown limited success in the treatment of patients. This lesson highlights current limitations and almost endless possibilities of cancer gene therapy. The major difficulty in advancing gene therapy technology for the lab bench to clinical practice is the problem with gene delivery vehicles (so-called vectors) needed to ferry genetic material into a cell. Despite few reports of therapeutic responses in some patients, there is still no proof of clinical efficacy of most cancer gene therapy approaches, primarily due to very low transduction and expression efficacy in vivo of available vectors. An "ideal" gene therapy vector should: be administered through a noninvasive route; target not only the primary tumor mass but disseminated tumor cells and micrometastases at distant and unreachable sites as well; carry a therapeutic gene with tumor-restricted and time-regulated and sustained expression. Current strategies for combating cancer with gene therapy can be subdivided into 4 basic concepts: 1) replacement of missing tumor suppressor gene and/or blocking of oncogenes or proinflammatory genes; 2) suicide gene strategies; 3) induction of immune-mediated destruction; and 4) inhibition of tumor angiogenesis. Clinical advance will probably come first from cooperation with standard cancer treatment such as chemotherapy, radiotherapy and immunotherapy.

The rat beta (b miny)-globin promoter: nuclear protein factors and erythroid-specific induction of transcription

We show that the rat adult beta (b miny)-globin gene is transcriptionally active. The - 100-bp promoter region contains control elements that are important for the induction of transcription in rat erythroleukemia (REL) cells. By using DNaseI footprinting and gel mobility shift assays, we have shown that the CCAAT box, a regulatory element from an analyzed promoter region, binds NF-Y and GATA-1 transcription factors. Another regulatory element from this region, betaDRE, binds erythroid-specific and ubiquitous factors from REL cells. Although both the CCAAT box region and betaDRE element bind the same protein factors before and after induction of REL cells, we show by South-Western blot analysis that the concentrations of 150-kDa, 70-kDa and 60-kDa factors binding to the betaDRE are increased in DMSO-induced REL cells.

Molecular evidence for increased hematopoietic proliferation in the spleen of the b/b laboratory rat

The splenomegaly and the appearance of a significant number of CFU-E (erythroid colony-forming units) and BFU-E1 (erythroid burst-forming units) in the Belgrade laboratory rat (b/b) spleen prompted us to analyse further the molecular evidence for increased hematopoietic proliferation in the b/b spleen. Messenger RNAs (mRNAs) specific for globins, proteins for iron transport and deposition and the band 3 protein were used in rat erythropoietic tissues as markers for proliferation and erythroid differentiation. In the b/b spleen, all mRNAs analysed display an erythroid-specific pattern of expression. This analysis also revealed an enhanced level of mRNA for ferritin in the +/b spleen, whereas erythrocyte-specific mRNA production was normal.