Иммунология и перспективы иммунотерапии злокачественных глиом: использование факторов гуморального иммунитета

High-grade gliomas are aggressive brain tumors with limited survival rates. To date the maximum of survival benefit of conventional therapeutic options has been already reached and innovative treatment strategies, based on tumor biology are urgently needed. Generally, malignant gliomas, including glioblastoma, are immunologically “cold: neoplasms, with weak anti-tumor immune response and peritumoral inflammation, caused by reduced expression of neoantigens by tumor cells and restricted immunoreactivity of the microenvironment. The reduced immunogenicity of brain structures is conditioned by the absence of homing molecules for white blood cells on them, as well as the suppression of activated (CD178+) T cells by brain gangliosides. The cell population infiltrating malignant glioma is impoverished with cytotoxic T cells (CD8+ FOXP3–) and oppositely enriched with regulatory T cells and type 2 macrophages (M2). An effective anti-glioma immune response is resulted in increasing the total number of tumor-infiltrating lymphocytes and the CD8+ cell content; switching the functional activity of macrophages from M2 to M1 type. Integration of immunotherapeutic technologies (vaccines and monoclonal antibodies) into treatment strategies of malignant gliomas is relevant and promising approach based on biological features of the tumor.Глиомы высокой степени злокачественности – агрессивные опухоли центральной нервной системы. Стандартная химиолучевая терапия данных новообразований не является куративной опцией, поэтому попытки усиления и индивидуализации их лечения на сегодняшний день предполагают воздействие на патогенетические механизмы роста опухоли на клеточном и молекулярно-генетическом уровнях. Злокачественные глиомы, в первую очередь глиобластомы, являются «холодными» опухолями, в которых иммунный ответ и перитуморальное воспаление проявляются слабо. Это объясняется сниженной экспрессией неоантигенов опухолевыми клетками и низкой иммунореактивностью микроокружения. Клетки центральной нервной системы лишены молекул для хоминга лейкоцитов, а поверхностные соединения – ганглиозиды – оказывают прямое ингибирующее воздействие на CD178+-цитотоксические Т-лимфоциты. Это приводит к тому, что популяция лейкоцитов, инфильтрирующих опухоль, представлена в основном клетками, отрицательно регулирующими иммунный ответ (регуляторными (CD4+ CD25+ FOXP3+) T-лимфоцитами и макрофагами 2-го типа). Макрофаги 2-го типа ингибируют клеточный иммунный ответ, стимулируют неоангиогенез и создают условия для метастатического распространения клеток опухоли.Интеграция в лечении опухолей центральной нервной системы иммунотерапевтических подходов, в том числе применение вакцин и моноклональных антител, является актуальной стратегией, основанной на биологических свойствах опухолевой ткани

Анализ генетических аберраций в глиомах высокой степени злокачественности у детей

Background. High-grade gliomas are characterized by a wide range of genetic abnormalities. The heterogeneous genomic landscape of pediatric high-grade gliomas allows identifying distinct subgroups of the disease in children and young adults. Most importantly, these subgroups differ by clinical course and prognosis, as well as treatment response to standard therapy.Objective: to assess the profile of molecular genetic markers of high-grade gliomas in children.Materials and methods. In the current study, we examine the frequency of H3F3A, Hist1H3B, BRAF, IDH1 / 2 mutations, the copy number alterations of CDKN2A / 2B genes and the expression of ETV6‑NTRK3 fusion gene in a cohort of 53 pediatric high-grade gliomas.Results. Driver mutations and CDKN2A / 2B deletions were observed in 24 (45 %) and 15 (28 %) of 53 tumors, respectively. Overall, the studied high-grade gliomas harbored 41 genetic aberrations including 24 (58.5 %) somatic missense mutations, 1 (2.4 %) genetic variant of unknown clinical significance, 1 (2.4 %) oncogenic fusion gene and 15 (36.6 %) deletions of the tumor suppressor genes.Conclusion. These findings point to the importance of molecular profiling of tumors for the optimal clinical care and development of new approaches to treatment aimed at molecular targets for personalized anticancer therapies.Введение. Высокозлокачественные глиомы характеризуются широким спектром генетических аномалий. Различия в молекулярно-генетическом профиле позволяют выделить несколько основных подгрупп глиом высокой степени злокачественности у детей и подростков, которые различаются как по клиническому течению заболевания, его прогнозу, так и по ответу на стандартные схемы терапии.Цель исследования – оценить профиль молекулярно-генетических маркеров глиом высокой степени злокачественности у детей.Материалы и методы. В исследование были включены 53 образца глиом высокой степени злокачественности у детей. Были проанализированы мутации в генах H3F3A, Hist1H3B, BRAF, IDH1/2, а также аномалии числа копий генов CDKN2A/2B и экспрессия химерного гена ETV6‑NTRK3.Результаты. В 24 (45 %) из 53 проанализированных случаев выявлена драйверная мутация в ткани опухоли, в 15 (28 %) – потеря копии CDKN2A / 2B, которая может выступать как второе мутационное событие. В общей сложности обнаружена 41 генетическая аберрация, из них 24 (58,5 %) составляют соматические миссенс-мутации, 1 (2,4 %) – вариант с неясным клиническим значением, 1 (2,4 %) – химерный онкоген и 15 (36,6 %) – делеции генов-онкосупрессоров.Заключение. Полученные данные свидетельствуют о важности углубленного изучения генетического профиля опухоли для определения тактики ведения пациентов, а также подбора персонализированной терапии для больных злокачественными глиомами

Transluminal angioplasty in postsurgical stenosis of the extracranial carotid artery.

Transluminal angioplasty of the common carotid artery was beneficial in a patient with postendarterectomy recurrent stenosis due to fibrous myointimal hyperplasia. This lesion is the major cause of restenosis within the first 24 postoperative months and has histologic characteristics quite favorable for angioplasty with minimal possibility for embolic complications. Since surgery is a proven procedure with low morbidity/mortality for most patients, the authors believe transluminal angioplasty for carotid restenosis should be limited to surgically inaccessible lesions or patients presenting unacceptable operative risk, as in the case described

Arteriovenous fistula simulating arteriovenous malformation.

A 36-year-old man was thought (for 20 years) to have an arteriovenous malformation that could not be excised. Repeated ligations of proximal arterial supply to the vascular lesion were only transiently beneficial and may have caused a delay in correct diagnosis because of impaired angioaccess. Once it was discovered that he had an arteriovenous fistula--probably caused by a tonsillectomy at age 6--it was possible to occlude the fistula with detachable balloons. The mass and his headaches subsequently resolved. AV fistulas are caused by trauma. Growth of AVMs is often stimulated by trauma. Both lesions have pulsatile masses associated with overlying bruits. The differential diagnosis can usually be made by arteriography, since AV fistulas are acquired lesions with a single communication between an artery and a vein, whereas AVMs are congenital lesions with multiple, large arterial feeding vessels and numerous arteriovenous communications. Proper diagnosis is important, since AVMs are aggressive lesions that tend to regrow if not completely excised. AV fistulas will be cured if the single arteriovenous communication can be obliterated. Proper treatment for AV fistula is obliteration of the single arteriovenous communication, operatively or with occlusive balloons; treatment of AVMs--when possible--is excision of the entire mass, combined (on occasion) with preoperative embolization of the tumor mass. This case report emphasizes the importance of accuracy in the differential diagnosis between arteriovenous malformations and arteriovenous fistulas; moreover, it demonstrates both the ineffectiveness and deleterious consequences of proximal arterial ligation, since collateral development is enhanced and angiographic access is compromised

Suppressed miR-128-3p combined with TERT overexpression predicts dismal outcomes for neuroblastoma

BACKGROUND: Molecular and clinical diversity of neuroblastomas is notorious. The activating TERT rearrangements have been associated with dismal prognosis. Suppression of miR-128-3p may complement and enhance the adverse effects of TERT overexpression. OBJECTIVE: The study aimed at evaluation of prognostic significance of the miR-128-3p/TERT expression in patients with primary neuroblastoma. METHODS: RNA samples isolated from fresh-frozen tumor specimens (n= 103) were reverse transcribed for evaluation of miR-128-3p and TERT expression by qPCR. The normalized expression levels were tested for correlations with the event-free survival (EFS). ROC-analysis was used to establish threshold expression levels (TLs) for the possible best prediction of the outcomes. The median follow-up was 57 months. RESULTS: Both TERT overexpression and miR-128-3p downregulation were independently associated with superior rates of adverse events (p= 0.027, TL =-2.32 log10 and p= 0.080, TL =-1.33 log10, respectively). The MYCN single-copy patients were stratified into groups based on the character of alterations in expression of the studied transcripts. Five-year EFS in the groups of patients with elevated TERT/normal miR-128-3p expression and normal TERT/reduced miR-128-3p expression were 0.74 ± 0.08 and 0.60 ± 0.16, respectively. The patients with elevated TERT/reduced miR-128-3p expression had the worst outcomes, with 5-year EFS of 0.40 ± 0.16 compared with 0.91 ± 0.06 for the patients with unaltered levels of both transcripts (p< 0.001). Cumulative incidence of relapse/progression for the groups constituted 0.23 ± 0.08, 0.40 ± 0.16, 0.60 ± 0.16 and 0.09 ± 0.06, respectively. Moreover, the loss of miR-128-3p was qualified as independent adverse predictor which outperformed the conventional clinical and genetic risk factors in the multivariate Cox regression model of EFS. CONCLUSIONS: Combined expression levels of miR-128-3p and TERT represent a novel prognostic biomarker for neuroblastoma

Congenital medulloblastoma: Fetal and postnatal longitudinal observation with quantitative MRI

Congenital medulloblastoma is extremely rare. MRI appearance of this tumor in the fetal brain has not been described. A case of congenital medulloblastoma initially observed by antenatal MRI with postnatal follow-up and treatment is presented. A pregnant female underwent fetal MRI on the 31st gestational week for routine indications. Midline cerebellar lesion of ≤2 cm in size with minor T2 hypointensity and T1 hyperintensity was identified. Additionally, quantitative MRI including apparent diffusion coefficient (ADC) and fast macromolecular proton fraction (MPF) mapping was performed. The lesion showed a marked ADC decrease and MPF increase. MPF maps depicted the lesion most conspicuously. After term delivery, a male neonate presented with symptoms of increased intracranial pressure. Postnatal MRI identified obstructive hydrocephalus caused by a large posterior fossa mass. The child was treated by cerebrospinal fluid shunt placement. Follow-up quantitative MRI on the fifth month revealed tumor growth and vivid changes of its tissue contrast associated with brain maturation. The tumor appeared nearly isointense on T1- and T2-weighted images and slightly hypointense on the ADC map. MPF contrast showed the most remarkable change from hyper- to hypointensity due to brain myelination with stable MPF in the tumor. Subsequently, the child underwent partial tumor resection, and currently continues treatment with chemotherapy. The pathological diagnosis was desmoplastic/nodular medulloblastoma. The described case illustrates evolution of the tumor contrast in the course of fetal and postnatal brain development and highlights the added diagnostic value of MPF mapping in fetal and neonatal neuroimaging

Analysis of genetic aberrations in pediatric high-grade gliomas

Background. High-grade gliomas are characterized by a wide range of genetic abnormalities. The heterogeneous genomic landscape of pediatric high-grade gliomas allows identifying distinct subgroups of the disease in children and young adults. Most importantly, these subgroups differ by clinical course and prognosis, as well as treatment response to standard therapy.Objective: to assess the profile of molecular genetic markers of high-grade gliomas in children.Materials and methods. In the current study, we examine the frequency of H3F3A, Hist1H3B, BRAF, IDH1 / 2 mutations, the copy number alterations of CDKN2A / 2B genes and the expression of ETV6‑NTRK3 fusion gene in a cohort of 53 pediatric high-grade gliomas.Results. Driver mutations and CDKN2A / 2B deletions were observed in 24 (45 %) and 15 (28 %) of 53 tumors, respectively. Overall, the studied high-grade gliomas harbored 41 genetic aberrations including 24 (58.5 %) somatic missense mutations, 1 (2.4 %) genetic variant of unknown clinical significance, 1 (2.4 %) oncogenic fusion gene and 15 (36.6 %) deletions of the tumor suppressor genes.Conclusion. These findings point to the importance of molecular profiling of tumors for the optimal clinical care and development of new approaches to treatment aimed at molecular targets for personalized anticancer therapies

Congenital medulloblastoma: Fetal and postnatal longitudinal observation with quantitative MRI

Congenital medulloblastoma is extremely rare. MRI appearance of this tumor in the fetal brain has not been described. A case of congenital medulloblastoma initially observed by antenatal MRI with postnatal follow-up and treatment is presented. A pregnant female underwent fetal MRI on the 31st gestational week for routine indications. Midline cerebellar lesion of ≤2 cm in size with minor T2 hypointensity and T1 hyperintensity was identified. Additionally, quantitative MRI including apparent diffusion coefficient (ADC) and fast macromolecular proton fraction (MPF) mapping was performed. The lesion showed a marked ADC decrease and MPF increase. MPF maps depicted the lesion most conspicuously. After term delivery, a male neonate presented with symptoms of increased intracranial pressure. Postnatal MRI identified obstructive hydrocephalus caused by a large posterior fossa mass. The child was treated by cerebrospinal fluid shunt placement. Follow-up quantitative MRI on the fifth month revealed tumor growth and vivid changes of its tissue contrast associated with brain maturation. The tumor appeared nearly isointense on T1- and T2-weighted images and slightly hypointense on the ADC map. MPF contrast showed the most remarkable change from hyper- to hypointensity due to brain myelination with stable MPF in the tumor. Subsequently, the child underwent partial tumor resection, and currently continues treatment with chemotherapy. The pathological diagnosis was desmoplastic/nodular medulloblastoma. The described case illustrates evolution of the tumor contrast in the course of fetal and postnatal brain development and highlights the added diagnostic value of MPF mapping in fetal and neonatal neuroimaging

Prospective investigation of applicability and the prognostic significance of bone marrow involvement in patients with neuroblastoma detected by quantitative reverse transcription PCR

Background: Detection of bone marrow (BM) involvement in patients with neuroblastoma is crucial for staging and defining prognosis. Furthermore, the persistence of residual tumor cells in the BM is associated with an unfavorable outcome. Methods: Expression of PHOX2B, TH, ELAVL4, and B4GALNT1 (GD2-synthase) was analyzed by quantitative polymerase chain reaction in neuroblastoma cell lines, control BM samples, and in BM samples from patients. The threshold level of expression for each gene was established through receiver operator characteristic analysis and used to determine the diagnostic test performance. The prognostic significance of BM involvement was assessed by survival rates calculations. The median of follow-up time was 36.1 months. Results: Neither PHOX2B nor TH expression was detected in control BM, while expression of ELAVL4 was found in 20 (76.9%) and GD2-synthase in 15 (57.7%) of 26 samples. The overall correct predictive value for TH, ELAVL4, and GD2-synthase, based on thresholds levels, was 0.952, 0.828, and 0.767, respectively, whereas the overall correct predictive value for PHOX2B was 0.994. The PHOX2B/TH expression in diagnostic BM of patients with neuroblastoma corresponded with a decreased survival rate (P  1.68 in the diagnostic BM samples demonstrated an adverse prognostic effect (P = 0.006). Persistence of PHOX2B/TH expression in the BM during and after induction chemotherapy resulted in dismal outcome (P = 0.022 and P = 0.012). Conclusion: PHOX2B and TH are the most optimal markers for detection of BM involvement, allowing identification of high-risk patients. Predominance of PHOX2B expression over TH has a strong adverse prognostic impact