Сравнение молекулярно-генетических методов выявления мутаций в гене CALR при миелопролиферативных заболеваниях

Molecular genetic detection of CALR gene somatic mutations is required for myeloproliferative neoplasms diagnosis and treatment according to the novel WHO clinical recommendations. CALR mutations are found in approximately 25–35 % cases of essential thrombocythemia and primary myelofibrosis and they are associated with benign clinical outcome. In this study we have compared sensitivity and selectivity of seve ral different options of CALR mutation molecular genetic detection in blood samples of 379 CMD patients and 17 healthy donors. Among methods compared in our study there have been conventional polymerase chain reaction with electrophoretic detection, real-time quantitative polymerase chain reaction, direct Sanger sequencing of polymerase chain reaction fragments and polymerase chain reaction high resolution melting curve analysis. By means of melting curve analysis CALR mutations have been found in 97 (25.5 %) patients, whereas in the cases of Sanger sequencing and polymerase chain reaction there have been 87 (23.0 %) and 84 (22.1 %) CALR mutation positive patients respectively.Молекулярно-генетические исследования для определения соматических мутаций в гене кальретикулина (CALR) включены в клинические рекомендации Всемирной организации здравоохранения в качестве одних из основных диагностических критериев миелопролиферативных заболеваний. Примерно в 25–35 % случаев эссенциальной тромбоцитемии и первичного миелофиброза бывают выявлены мутации в гене CALR, наличие которых ассоциировано с благоприятным прогнозом течения заболевания. В нашем исследовании выполнено сравнение результатов молекулярно-генетических методов для определения мутаций в гене CALR. Проведен анализ образцов периферической крови 379 пациентов с хроническими миелопролиферативными заболеваниями и 17 образцов крови здоровых доноров. Наличие мутаций в гене CALR определяли методом полимеразной цепной реакции с электрофоретической детекцией и количественной полимеразной цепной реакции в реальном времени, методом секвенирования по Сэнгеру и анализом кривых плавления. Мутации в гене CALR определены у 97 (25,5 %) пациентов методом анализа кривых плавления. Из них у 87 (23,0 %) пациентов мутации в гене найдены методом секвенирования по Сэнгеру. С помощью полимеразной цепной реакции мутации в гене CALR были обнаружены у 84 (22,1 %) пациентов

Проблема химиорезистентности PRAME-экспрессирующей клетки меланомы и способ ее преодоления c помощью бортезомиба

Background. PRAME gene spontaneous expression is frequently observed in a cancer cell. The protein encoded by this gene increases  the viability of tumour cell. NF-κB signalling pathway takes part in PRAME upregulation. It proposes, that stress conditions may increase the expression level of PRAME in the tumour cell and increase cell’s viability after it. We hypothesized that this phenomenon determines chemoresistance of PRAME-expressing cell, which can be overcome by NF-κB inhibitors, such as bortezomib.Materials and methods. We incubated A875 melanoma cells with cisplatin, bortezomib and dexamethasone, as well as with a mixture  of cisplatin with bortezomib and cisplatin with dexamethasone within 24 hours. To assess the cytotoxicity of these combinations MTT-test was used. For evaluation of PRAME expression level, real-time polymerase chain reaction was used. All data were analyzed with Wilcoxon test for coupled samples.Results. It was found that cisplatin and dexamethasone increased an expression level of PRAME compared to control (p <0.03). The addition of dexamethasone to cisplatin reduced cytotoxic effect of cisplatin. Bortezomib has a cytotoxic effect, but it did not increase the activity  of PRAME gene (p = 0.12). PRAME gene activity in cells incubated with a mixture of cisplatin and bortezomib was observed at a lower level in comparison with cells incubated with cisplatin (p = 0.0277).Conclusion. The results of experiments show that an increase of PRAME expression level reduces the sensitivity of melanoma cells to the cytotoxic effect of cisplatin. PRAME activity increases under stress conditions. Using of bortezomib can inhibit the growth of PRAME expression and makes the tumour cell more vulnerable to cytotoxic agents. On the other hand, dexamethasone may increase a resistance  of PRAME-expressing cell to cytotoxic effects.Введение. В настоящее время показано, что активность раково-тестикулярного гена PRAME, характерная только для опухолевой клетки, может контролироваться сигнальным каскадом NF-κB. Белок PRAME увеличивает жизнеспособность опухолевой клетки. Отсюда следует, что стрессовые условия могут повышать уровень экспрессии PRAME и увеличивать жизнеспособность опухолевой клетки. Мы предположили, что данный феномен определяет химиорезистентность PRAME-экспрессирующей клетки. Эту резистентность можно преодолеть ингибиторами NF-κB-пути, такими как бортезомиб.Материалы и методы: инкубирование в течение суток клеток меланомы линии A875 с цисплатином, бортезомибом и дексаметазоном, смесью цисплатина и бортезомиба, а также со смесью цисплатина и дексаметазона. Для оценки цитотоксичности применяемых препаратов использовали МТТ-тест, уровня экспрессии гена PRAME – полимеразную цепную реакцию в реальном времени. Анализ данных проводили с помощью критерия Вилкоксона для связанных выборок.Результаты. Установлено, что цисплатин и дексаметазон увеличивают уровень экспрессии PRAME по сравнению с клетками меланомы линии A875, не подвергнутыми действию экспериментальных веществ (p <0,03). Добавление дексаметазона к цисплатину снижает цитотоксический эффект последнего. Бортезомиб обладает цитотоксическим действием, но практически не увеличивал активность гена PRAME (p = 0,12). В клетках, инкубированных со смесью цисплатина и бортезомиба, активность гена PRAME находилась на более низком уровне по сравнению с клетками, инкубированными с цисплатином (p = 0,0277).Заключение. Результаты экспериментов показывают, что увеличение уровня экспрессии гена PRAME снижает чувствительность клеток к цитотоксическому действию цисплатина. Активность PRAME увеличивается в условиях стресса. Применение бортезомиба препятствует росту уровня экспрессии PRAME и делает опухолевую клетку более уязвимой к цитотоксическим агентам. С другой стороны, дексаметазон может увеличить резистентность PRAME-экспрессирующей клетки к цитотоксическому воздействию цисплатина

Comparison of molecular genetic methods of detection of mutations in the CALR gene in myeloproliferative disorders

Molecular genetic detection of CALR gene somatic mutations is required for myeloproliferative neoplasms diagnosis and treatment according to the novel WHO clinical recommendations. CALR mutations are found in approximately 25–35 % cases of essential thrombocythemia and primary myelofibrosis and they are associated with benign clinical outcome. In this study we have compared sensitivity and selectivity of seve ral different options of CALR mutation molecular genetic detection in blood samples of 379 CMD patients and 17 healthy donors. Among methods compared in our study there have been conventional polymerase chain reaction with electrophoretic detection, real-time quantitative polymerase chain reaction, direct Sanger sequencing of polymerase chain reaction fragments and polymerase chain reaction high resolution melting curve analysis. By means of melting curve analysis CALR mutations have been found in 97 (25.5 %) patients, whereas in the cases of Sanger sequencing and polymerase chain reaction there have been 87 (23.0 %) and 84 (22.1 %) CALR mutation positive patients respectively

Chemoresistance of PRAME-expressing melanoma cell can be resolved with help of bortezomib

Background. PRAME gene spontaneous expression is frequently observed in a cancer cell. The protein encoded by this gene increases  the viability of tumour cell. NF-κB signalling pathway takes part in PRAME upregulation. It proposes, that stress conditions may increase the expression level of PRAME in the tumour cell and increase cell’s viability after it. We hypothesized that this phenomenon determines chemoresistance of PRAME-expressing cell, which can be overcome by NF-κB inhibitors, such as bortezomib.Materials and methods. We incubated A875 melanoma cells with cisplatin, bortezomib and dexamethasone, as well as with a mixture  of cisplatin with bortezomib and cisplatin with dexamethasone within 24 hours. To assess the cytotoxicity of these combinations MTT-test was used. For evaluation of PRAME expression level, real-time polymerase chain reaction was used. All data were analyzed with Wilcoxon test for coupled samples.Results. It was found that cisplatin and dexamethasone increased an expression level of PRAME compared to control (p <0.03). The addition of dexamethasone to cisplatin reduced cytotoxic effect of cisplatin. Bortezomib has a cytotoxic effect, but it did not increase the activity  of PRAME gene (p = 0.12). PRAME gene activity in cells incubated with a mixture of cisplatin and bortezomib was observed at a lower level in comparison with cells incubated with cisplatin (p = 0.0277).Conclusion. The results of experiments show that an increase of PRAME expression level reduces the sensitivity of melanoma cells to the cytotoxic effect of cisplatin. PRAME activity increases under stress conditions. Using of bortezomib can inhibit the growth of PRAME expression and makes the tumour cell more vulnerable to cytotoxic agents. On the other hand, dexamethasone may increase a resistance  of PRAME-expressing cell to cytotoxic effects

Emotional processing in Parkinson's disease and anxiety: an EEG study of visual affective word processing

A general problem in the design of an EEG-BCI system is the poor quality and low robustness of the extracted features, affecting overall performance. However, BCI systems that are applicable in real-time and outside clinical settings require high performance. Therefore, we have to improve the current methods for feature extraction. In this work, we investigated EEG source reconstruction techniques to enhance the extracted features based on a linearly constrained minimum variance (LCMV) beamformer. Beamformers allow for easy incorporation of anatomical data and are applicable in real-time. A 32-channel EEG-BCI system was designed for a two-class motor imagery (MI) paradigm. We optimized a synchronous system for two untrained subjects and investigated two aspects. First, we investigated the effect of using beamformers calculated on the basis of three different head models: a template 3-layered boundary element method (BEM) head model, a 3-layered personalized BEM head model and a personalized 5-layered finite difference method (FDM) head model including white and gray matter, CSF, scalp and skull tissue. Second, we investigated the influence of how the regions of interest, areas of expected MI activity, were constructed. On the one hand, they were chosen around electrodes C3 and C4, as hand MI activity theoretically is expected here. On the other hand, they were constructed based on the actual activated regions identified by an fMRI scan. Subsequently, an asynchronous system was derived for one of the subjects and an optimal balance between speed and accuracy was found. Lastly, a real-time application was made. These systems were evaluated by their accuracy, defined as the percentage of correct left and right classifications. From the real-time application, the information transfer rate (ITR) was also determined. An accuracy of 86.60 ± 4.40% was achieved for subject 1 and 78.71 ± 0.73% for subject 2. This gives an average accuracy of 82.66 ± 2.57%. We found that the use of a personalized FDM model improved the accuracy of the system, on average 24.22% with respect to the template BEM model and on average 5.15% with respect to the personalized BEM model. Including fMRI spatial priors did not improve accuracy. Personal fine- tuning largely resolved the robustness problems arising due to the differences in head geometry and neurophysiology between subjects. A real-time average accuracy of 64.26% was reached and the maximum ITR was 6.71 bits/min. We conclude that beamformers calculated with a personalized FDM model have great potential to ameliorate feature extraction and, as a consequence, to improve the performance of real-time BCI systems