Brain radiotoxicity-related 15CAcBRT gene expression signature predicts survival prognosis of glioblastoma patients.

BACKGROUND: Glioblastoma is the most common and devastating primary brain cancer. Radiotherapy is standard of care; however, it is associated with brain radiation toxicity (BRT). This study used a multi-omics approach to determine whether BRT-related genes (RGs) harbor survival prognostic value and whether their encoded proteins represent novel therapeutic targets for glioblastoma. METHODS: RGs were identified through analysis of single-nucleotide variants associated with BRT (R-SNVs). Functional relationships between RGs were established using Protein-Protein Interaction networks. The influence of RGs and their functional groups on glioblastoma prognosis was evaluated using clinical samples from the Glioblastoma Bio-Discovery Portal database and validated using the Chinese Glioma Genome Atlas dataset. The identification of clusters of radiotoxic and putative pathogenic variants in proteins encoded by RGs was achieved by computational 3D structural analysis. RESULTS: We identified the BRT-related 15CAcBRT molecular signature with prognostic value in glioblastoma, by analysis of the COMT and APOE protein functional groups. Its external validation confirmed clinical relevance independent of age, MGMT promoter methylation status, and IDH mutation status. Interestingly, the genes IL6, APOE, and MAOB documented significant gene expression levels alteration, useful for drug repositioning. Biological networks associated with 15CAcBRT signature involved pathways relevant to cancer and neurodegenerative diseases. Analysis of 3D clusters of radiotoxic and putative pathogenic variants in proteins coded by RGs unveiled potential novel therapeutic targets in neuro-oncology. CONCLUSIONS: 15CAcBRT is a BRT-related molecular signature with prognostic significance for glioblastoma patients and represents a hub for drug repositioning and development of novel therapies.

Serum anti-neural immunoreactivity in patients with fibromyalgia. Preliminary study.

INTRODUCTION: Fibromyalgia (FM) is a non-degenerative syndrome characterized by generalized, chronic musculoskeletal pain, as well as mood, memory and sleep disorders. OBJECTIVE: To search for serum anti-neural antibodies (ANeuA) in patients with FM (FMP) in order to rule out autoimmune etiology. METHODS: The Fibromyalgia Impact Questionnaire (FIQ) and Beck's depression inventory (BDI) were applied. Immunoreactivity and the target recognized on the sera from FMPs and healthy subjects were analyzed by indirect immunofluorescence and Western blot. RESULTS: Both FIQ and BDI values were significantly altered in FMPs in comparison with those of controls (FIQ, 70 ± 25 vs. 12 ± 12, p < 0.0001; BDI, 17 ± 11 vs. 4 ± 3, p < 0.0002). Only five out of 15 FMP sera had ANeuA specifically directed against neurons from the medial vestibular nucleus of the brainstem. This immunoreactivity was not detected in the sera from the 14 controls. ANeuA recognized a 45 kDa protein. CONCLUSIONS: 30% of FMPs have ANeuA that have not been described before. In future studies, it will be necessary for anti-neural immunoreactivity to be determined in a larger sample and for the role of ANeuAs in the pathophysiology of FM to be established.

INTRODUCCIÓN: La fibromialgia (FM) es un síndrome no degenerativo caracterizado por dolor musculoesquelético crónico y generalizado; así como por alteraciones anímicas, de memoria y sueño. OBJETIVO: Buscar anticuerpos antineurales (AANeu) séricos en pacientes con FM para descartar etiología autoinmune. MÉTODOS: Se aplicó el Cuestionario de Impacto en Fibromialgia (FIQ) y el Inventario de Depresión de Beck (BDI). La inmunorreactividad y el blanco reconocido por los sueros de pacientes con FM y sujetos sanos se analizó con inmunofluorescencia indirecta y Western blot. RESULTADOS: Los valores de FIQ y BDI estuvieron significativamente alterados en los pacientes con FM, en comparación con los de los controles (FIQ, 70 ± 25 versus 12 ± 12, p < 0.0001; BDI, 17 ± 11 versus 4 ± 3, p < 0.0002). Solo cinco de 15 sueros de pacientes con FM tuvieron AANeu dirigidos específicamente contra las neuronas del núcleo vestibular medio del tronco encefálico; estos no se detectaron en los 14 sueros de los controles. Los AANeu reconocieron una proteína de 45 kDa. CONCLUSIONES: El 30 % de los pacientes con FM tiene AANeu no descritos antes. Será necesario evaluar la inmunorreactividad antineural en una muestra más grande y determinar el papel de los AANeu en la fisiopatología de la FM.

Seric IgG anti-SARS-CoV-2 pre- and post- Covid-19 pandemic from Mexican asymptomatic subjects / IgG sérica anti-SARS-CoV-2 pre y post pandemia de Covid-19 en mexicanos asintomáticos

Abstract: Objective: To detect serum IgG anti-SARS-CoV-2 in pre- and post- Covid-19 pandemic in Mexican asymptomatic subjects in order to know the degree of viral dispersion. Materials and methods: Association of serum IgG antibodies (determined by ELISA) to sociodemographic and clinical data or contact with Covid-19 cases in three groups of subjects: 1) Covid-19 pre-pandemic blood donors (n= 538); 2) Covid-19 post-pandemic blood donors (n= 243); 3) Covid-19 post-pandemic neurological patients (n= 312). None of the subjects studied had been vaccinated. Results: The positive rate of IgG anti-SARS-CoV-2 was notably higher in participants recruited during the pandemic (donors, 29.6%; neurological patients, 15.7%) than in those recruited pre-pandemic (donors 0.6%) (p <0.001). Other conditions associated to antibody positivity were being a worker in sales or services, or having had previous contact with people with Covid-19, for donnors and neurological patients, and having diabetes mellitus, for neurological patients. Higher positivity levels of anti-SARS-CoV-2 IgG were found in females than in males. The highest proportion of subjects with anti-SARS-CoV-2 antibodies was found in central Mexico. Conclusions: The dispersion of SARS-CoV-2 in asymptomatic, unvaccinated subjects (donors and neurological patients) recruited in a Mexican health institution, who work in sales or services or had previously had contact with Covid-19 patients is 16 to 30%. The level of positivity for anti-SARS-CoV-2 IgG is higher in females than in males. SARS-CoV-2 antibody seroprevalence follow-up studies must be favored among the general population, being mandatory for donors.

Resumen: Objetivo: Detectar IgG sérica anti-SARS-CoV-2 antes y después de la pandemia de Covid-19 en sujetos mexicanos asintomáticos, con la intención de conocer el grado de dispersión viral. Material y métodos: Se analizó la asociación de anticuerpos IgG séricos (determinados por ELISA), datos sociodemográficos y clínicos y contacto con casos de Covid-19 en tres grupos de sujetos: 1) donadores de sangre reclutados antes de la pandemia de Covid-19 (n= 538); 2) donadores (n= 243) y 3) pacientes neurológicos (n= 312) reclutados durante la pandemia de Covid-19. Ninguno de los sujetos estudiados había sido vacunado. Resultados: La tasa de positividad de IgG anti-SARS-CoV-2 fue notablemente mayor en los participantes reclutados durante la pandemia (donadores, 29.6%; pacientes neurológicos, 15.7%) que en los reclutados prepandemia (donadores 0.6%). Otras condiciones asociadas con positividad de anticuerpos fueron trabajar en ventas o servicios, o haber tenido contacto previo con pacientes Covid-19, en donadores y pacientes neurológicos, y haber tenido diabetes mellitus, en pacientes neurológicos. Se encontraron mayores niveles de positividad de IgG anti-SARS-CoV-2 en mujeres que en hombres. La mayor proporción de sujetos con anticuerpos anti-SARS-CoV-2 procedía del centro de México. Conclusiones: La dispersión del SARS-CoV-2 en sujetos asintomáticos, no vacunados (donadores y pacientes neurológicos), reclutados en una institución de salud mexicana, que trabajan en ventas o servicios, o tienen contacto previo con pacientes Covid-19 es de 16 a 30%. El nivel de positividad de IgG anti-SARS-CoV-2 es más alto en mujeres que en hombres. Los estudios de seguimiento de la seroprevalencia del SARS-CoV-2 deben favorecerse en la población general, siendo obligatorios en los donadores.

Inmunorreactividad antineural sérica en pacientes con fibromialgia. Estudio preliminar / Serum anti-neural immunoreactivity in patients with fibromyalgia. Preliminary study

Resumen Introducción: La fibromialgia (FM) es un síndrome no degenerativo caracterizado por dolor musculoesquelético crónico y generalizado; así como por alteraciones anímicas, de memoria y sueño. Objetivo: Buscar anticuerpos antineurales (AANeu) séricos en pacientes con FM para descartar etiología autoinmune. Métodos: Se aplicó el Cuestionario de Impacto en Fibromialgia (FIQ) y el Inventario de Depresión de Beck (BDI). La inmunorreactividad y el blanco reconocido por los sueros de pacientes con FM y sujetos sanos se analizó con inmunofluorescencia indirecta y Western blot. Resultados: Los valores de FIQ y BDI estuvieron significativamente alterados en los pacientes con FM, en comparación con los de los controles (FIQ, 70 ± 25 versus 12 ± 12, p < 0.0001; BDI, 17 ± 11 versus 4 ± 3, p < 0.0002). Solo cinco de 15 sueros de pacientes con FM tuvieron AANeu dirigidos específicamente contra las neuronas del núcleo vestibular medio del tronco encefálico; estos no se detectaron en los 14 sueros de los controles. Los AANeu reconocieron una proteína de 45 kDa. Conclusiones: El 30 % de los pacientes con FM tiene AANeu no descritos antes. Será necesario evaluar la inmunorreactividad antineural en una muestra más grande y determinar el papel de los AANeu en la fisiopatología de la FM.

Abstract Introduction: Fibromyalgia (FM) is a non-degenerative syndrome characterized by generalized, chronic musculoskeletal pain, as well as mood, memory and sleep disorders. Objective: To search for serum anti-neural antibodies (ANeuA) in patients with FM (FMP) in order to rule out autoimmune etiology. Methods: The Fibromyalgia Impact Questionnaire (FIQ) and BECK’s depression inventory (BDI) were applied. Immunorreactivity and the target recognized on the sera from FMPs and healthy subjects were analyzed by indirect immunofluorescence and Western blot. Results: Both FIQ and BDI values were significantly altered in FMPs in comparison with those of controls (FIQ, 70 ± 25 vs. 12 ± 12, p < 0.0001; BDI, 17 ± 11 vs. 4 ± 3, p < 0.0002). Only five out of 15 FMP sera had ANeuA specifically directed against neurons from the medial vestibular nucleus of the brainstem. This immunoreactivity was not detected in the sera from the 14 controls. ANeuA recognized a 45 kDa protein. Conclusions: 30% of FMPs have ANeuA that have not been described before. In future studies, it will be necessary for anti-neural immunoreactivity to be determined in a larger sample and for the role of ANeuAs in the pathophysiology of FM to be established.

[Descriptive epidemiology and frequency variations of astrocytic tumors in the National Institute of Neurology and Neurosurgery of Mexico]. / Epidemiología descriptiva y cambios en la frecuencia de tumores astrocíticos en el Instituto Nacional de Neurología y Neurocirugía de México.

OBJECTIVE: To determine distribution, localization and frequency variations of astrocytic tumors (AT) in a Mexican Institute of neurology. MATERIALS AND METHODS: Institutional registries of AT from five decades were analyzed. AT/ Surgical discharges (SD) and AT/Central Nervous System Tumors (CNST) from 1995 to 2014 were compared. RESULTS: Two thousand two hundred and eighty-seven AT (1 356 men and 931 women) were analyzed. The most common glioma was glioblastoma multiforme (GBM), found in young adults with a higher frequency to that reported in other studies. Relation of AT/SD, as well as, relation of AT/CNST was similar between 1995 and 2014. CONCLUSIONS: In general, the frequency of AT worldwide, being higher in the subgroup of young adults with GBM. There was not significant variation in the frequency of AT during the time studied.

OBJETIVO: Determinar distribución, localización y cambios de la frecuencia de tumores astrocíticos (TA) en un instituto mexicano de neurología. MATERIAL Y MÉTODOS: Se revisaron los registros institucionales de TA de cinco décadas. Se compararon las relaciones TA/egresos quirúrgicos (EQ) y TA/total de tumores del sistema nervioso central (TSNC) de 1995 a 2014. RESULTADOS: Se analizaron 2 287 TA (1 356 en hombres y 931 en mujeres). El glioma más común fue el glioblastoma multiforme (GBM), que estuvo presente en adultos jóvenes con una frecuencia mayor a la reportada en otros estudios. La relación TA/EQ y TA/TNSC fue similar entre 1995 y 2014. CONCLUSIONES: En general, la frecuencia de TA atendidos en el Instituto es similar a la reportada internacionalmente. No obstante, los casos de TA en el subgrupo de adultos jóvenes con GBM son más frecuentes (40%) que las incidencias reportadas en otros estudios (menores al 5%). No se encontró variación significativa en la frecuencia de TA durante las últimas dos décadas.

Epidemiología descriptiva y cambios en la frecuencia de tumores astrocíticos en el Instituto Nacional de Neurología y Neurocirugía de México / Descriptive epidemiology and frequency variations of astrocytic tumors in the National Institute of Neurology and Neurosurgery of Mexico

Resumen: Objetivo: Determinar distribución, localización y cambios de la frecuencia de tumores astrocíticos (TA) en un instituto mexicano de neurología. Material y métodos: Se revisaron los registros institucionales de TA de cinco décadas. Se compararon las relaciones TA/egresos quirúrgicos (EQ) y TA/total de tumores del sistema nervioso central (TSNC) de 1995 a 2014. Resultados: Se analizaron 2 287 TA (1 356 en hombres y 931 en mujeres). El glioma más común fue el glioblastoma multiforme (GBM), que estuvo presente en adultos jóvenes con una frecuencia mayor a la reportada en otros estudios. La relación TA/EQ y TA/TNSC fue similar entre 1995 y 2014. Conclusiones: En general, la frecuencia de TA atendidos en el Instituto es similar a la reportada internacionalmente. No obstante, los casos de TA en el subgrupo de adultos jóvenes con GBM son más frecuentes (40%) que las incidencias reportadas en otros estudios (menores al 5%). No se encontró variación significativa en la frecuencia de TA durante las últimas dos décadas.

Abstract: Objective: To determine distribution, localization and frequency variations of astrocytic tumors (AT) in a Mexican Institute of neurology. Materials and methods: Institutional registries of AT from five decades were analyzed. AT/Surgical discharges (SD) and AT/Central Nervous System Tumors (CNST) from 1995 to 2014 were compared. Results: Two thousand two hundred and eighty-seven AT (1 356 men and 931 women) were analyzed. The most common glioma was glioblastoma multiforme (GBM), found in young adults with a higher frequency to that reported in other studies. Relation of AT/SD, as well as, relation of AT/CNST was similar between 1995 and 2014. Conclusions: In general, the frequency of AT attended at the Institute is similar to that found worldwide, being only higher the number of GBM in younger adults. There was not significant variation in the frequency of AT during the time studied.

Historical distribution of central nervous system tumors in the Mexican National Institute of Neurology and Neurosurgery.

OBJECTIVE: To determine the frequency of central nervous system (CNS) tumors in the first fifty years of the National Institute of Neurology and Neurosurgery of Mexico Manuel Velasco Suárez (Instituto Nacional de Neurología y Neurocirugía de México, INNN) from 1965 to 2014. MATERIALS AND METHODS: A total of 16 116 institutional records of CNS tumors were analyzed. The frequency and distribution of CNS tumors were evaluated by tumor type, patient age and patient gender. The annual relationship between CNS tumors and surgical discharges (SD) over the last 20 years was estimated. RESULTS: The frequencies of most CNS tumors were consistent with those found worldwide, and the most common tumors were neuroepithelial tumors (33%), particularly astrocytic tumors (67%); meningeal tumors (26%); and pituitary tumors (20%). The incidence of pituitary tumors in these data was twice as high as that reported in other regions of the world, and the relationship between CNS tumors and SD was consistent over time (0.22-0.39). CONCLUSION: This study summarizes the largest sample of CNS tumor cases analyzed in Mexico and provides an important reference of the frequency of this tumor type in the country. This work will serve as a basis for conducting studies evaluating factors associated with the presence of CNS tumors and for identifying adequate public health interventions.

Historical distribution of central nervous system tumors in the Mexican National Institute of Neurology and Neurosurgery / Distribución histórica de neoplasias del sistema nervioso central en el Instituto Nacional de Neurología y Neurocirugía de México

Abstract Objective: To determine the frequency of central nervous system (CNS) tumors in the first fifty years of the National Institute of Neurology and Neurosurgery of Mexico Manuel Velasco Suárez (Instituto Nacional de Neurología y Neurocirugía de México, INNN) from 1965 to 2014. Materials and methods: A total of 16 116 institutional records of CNS tumors were analyzed. The frequency and distribution of CNS tumors were evaluated by tumor type, patient age and patient gender. The annual relationship between CNS tumors and surgical discharges (SD) over the last 20 years was estimated. Results: The frequencies of most CNS tumors were consistent with those found worldwide, and the most common tumors were neuroepithelial tumors (33%), particularly astrocytic tumors (67%); meningeal tumors (26%); and pituitary tumors (20%). The incidence of pituitary tumors in these data was twice as high as that reported in other regions of the world, and the relationship between CNS tumors and SD was consistent over time (0.22-0.39). Conclusion: This study summarizes the largest sample of CNS tumor cases analyzed in Mexico and provides an important reference of the frequency of this tumor type in the country. This work will serve as a basis for conducting studies evaluating factors associated with the presence of CNS tumors and for identifying adequate public health interventions.

Resumen Objetivo: Determinar la frecuencia de neoplasias del sistema nervioso central (NSNC) en los primeros 50 años del Instituto Nacional de Neurología y Neurocirugía de México (INNN). Material y métodos: Se analizaron 16 116 registros institucionales de las NSNC, atendidas en el INNN de 1965 a 2014; se estimó su frecuencia y distribución por tipo de neoplasia, edad y género, y se determinó la relación anual de NSNC y egresos quirúrgicos (EQ) en un período de 20 años. Resultados: Las frecuencias de la mayoría de NSNC fueron consistentes con las encontradas a nivel mundial. Las más frecuentes fueron las neuroepiteliales (33%), entre las cuales destacaron las astrocíticas (67%); meníngeas (26%), e hipofisiarias (20%). El número de neoplasias hipofisiarias en esta serie fue dos veces mayor al reportado en otras regiones del mundo y la relación NSNC/EQ fue similar a través del tiempo (0.22-0.39). Conclusión: Ésta es la mayor serie de casos de NSNC analizados en México y proporciona un referente importante sobre la frecuencia de este tipo de neoplasias en el país. Este trabajo servirá de base para llevar a cabo estudios de los factores asociados a la presencia de NSNC e identificar intervenciones de salud pública adecuadas.

IL-8 and IL-6 primarily mediate the inflammatory response in fibromyalgia patients.

Fibromyalgia (FM) is a chronic disease that has been linked to inflammatory reactions and changes in the systemic levels of proinflammatory cytokines that modulate responses in the sympathetic nervous system and hypothalamic-pituitary-adrenal axis. We found that concentrations of IL-6 and IL-8 were elevated in FM patients. Both cytokines correlated with clinical scores, suggesting that IL-6 and IL-8 have additive or synergistic effects in perpetuating the chronic pain in FM patients. These findings indicate that IL-6 and IL-8 are two of the most constant inflammatory mediators in FM and that their levels correlate significantly with the severity of symptoms.

Chronic deep brain stimulation of the hypothalamic nucleus in wistar rats alters circulatory levels of corticosterone and proinflammatory cytokines.

Deep brain stimulation (DBS) is a therapeutic option for several diseases, but its effects on HPA axis activity and systemic inflammation are unknown. This study aimed to detect circulatory variations of corticosterone and cytokines levels in Wistar rats, after 21 days of DBS-at the ventrolateral part of the ventromedial hypothalamic nucleus (VMHvl), unilateral cervical vagotomy (UCVgX), or UCVgX plus DBS. We included the respective control (C) and sham (S) groups (n = 6 rats per group). DBS treated rats had higher levels of TNF-α (120%; P < 0.01) and IFN-γ (305%; P < 0.001) but lower corticosterone concentration (48%; P < 0.001) than C and S. UCVgX animals showed increased corticosterone levels (154%; P < 0.001) versus C and S. UCVgX plus DBS increased IL-1ß (402%; P < 0.001), IL-6 (160%; P < 0.001), and corsticosterone (178%; P < 0.001 versus 48%; P < 0.001) compared with the C and S groups. Chronic DBS at VMHvl induced a systemic inflammatory response accompanied by a decrease of HPA axis function. UCVgX rats experienced HPA axis hyperactivity as result of vagus nerve injury; however, DBS was unable to block the HPA axis hyperactivity induced by unilateral cervical vagotomy. Further studies are necessary to explore these findings and their clinical implication.

[Steroid drugs and GM-CSF modulates activity of Egr-1 in glioma cells]. / Fármacos esteroides y el GM-CSF modulan la actividad de Egr-1 en células de glioma.

INTRODUCTION: The Egr-1 protein is a transcriptional factor responsive to early growth. Transcriptional regulation of the promoter has been described like responsive to physical stress, osmotic changes, and cellular growth marker. However, there is no report about the pharmacological effect on the transcriptional regulation in gliomas. Hereby we report the modulation of the Egr-1 promoter transcriptional activity induced by the Granulocytes Macrophages Colony Stimulating Factor (GM-CSF) and steroid drugs in human glioma cells (CH235-GM Grade II, U373-GM Grade III, D54-GM Grade IV) using a reporter system transduced by a recombinant adenoviral vector AdEgr-1/luc7. METHODS: Human glioma cells shows with different malignity grade (CH235-GM Grado II; U373-GM Grado III; D54-GM Grado IV) were transduced with no replicative adenoviral vector AdEgr-1/Luc7 and exposed to drugs as progesterone, ß-estradiol and betametasone, and GM-CSF. Transcriptional activity of the egr-1 promoter was quantified by Luciferase reporter gene, cloned downstream to the tata box. Luciferase activity was quantified from whole cell proteins using luminometry assays. RESULTS: U373-GM cell line with GM-CSF, shows an increment on transcriptional activity of Egr-1 promoter, also in endogen way. U373-GM showed a positive regulation of Egr-1, with steroid drugs on the times analyzed. Steroid drugs as progesterone, ß-estradiol and betametasone, shows a pleiotropic behavior on CH235-GM and D54-GM, glioma cell lines. CONCLUSIONS: Inhibition or activation response of Egr-1 promoter shows new framework to explore a mechanism of action of steroid drugs on genetic and epigenetic regulation on tumoral process.

Short communication: preferential concentration of hydroxychloroquine in adenoid tissue of HIV-infected subjects.

Hydroxychloroquine (HCQ) anti-HIV activity is well documented. To evaluate its distribution in lymphoid tissues, which are considered sanctuaries of HIV reservoirs and targets of early massive depletion of CD4(+) T cells, we assessed HCQ concentrations in adenoid tissue and plasma of HIV-infected subjects. A daily oral dose of 400 or 800 mg of HCQ was administered to eight HIV-infected subjects for 8 days. HCQ concentrations were measured in plasma and adenoid tissue by high-performance liquid chromatography. Mean concentrations of HCQ in adenoid tissue of subjects treated with 400 and 800 mg were 87,210 +/- 17,817 and 167,472 +/- 93,793 ng/g, respectively. In plasma, these values corresponded to 329 +/- 133 and 278 +/- 68 ng/g, respectively. HCQ concentrations were significantly higher in adenoid tissue than in plasma in both groups. The potential use of HCQ as adjuvant in the therapy of HIV deserves to be explored, as the drug accumulates in relevant tissues for HIV replication and immunopathogenesis.

Clinical relevance of non-neuronal auto-antibodies in patients with anti-Hu or anti-Yo paraneoplastic diseases.

About half of the patients with paraneoplastic diseases develop an immune response against neuronal antigens expressed by both the tumor and the nervous system. In 31 patients with anti-Hu antibodies and 19 patients with anti-Yo antibodies, we searched for the presence of additional non-neuronal auto-antibodies and further studied whether the presence of such auto-antibodies was correlated with a specific oncological or neurological presentation. Positive antinuclear antibodies (ANA) were found at a titer of 1:40 or above in 48% patients with anti-Hu antibodies, and in 37% patients with anti-Yo antibodies. Anti-cytoplasmic antibodies were also detected in 42% patients with anti-Yo antibodies. No specific correlation between the presence of non-neuronal auto-antibodies and clinical characteristics of the patients could be identified. In particular, neither the type of underlying cancer, the overall survival, the tumor response to treatment, nor the neurological presentation were related to the serological status.

CpG island hypermethylation of the DNA repair enzyme methyltransferase predicts response to temozolomide in primary gliomas.

PURPOSE: The DNA repair enzyme O(6)-methylguanine DNA methyltransferase (MGMT) inhibits the killing of tumor cells by alkylating agents, and its loss in cancer cells is associated with hypermethylation of the MGMT CpG island. Thus, methylation of MGMT has been correlated with the clinical response to 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) in primary gliomas. Here, we investigate whether the presence of MGMT methylation in gliomas is also a good predictor of response to another emergent alkylating agent, temozolomide. EXPERIMENTAL DESIGN: Using a methylation-specific PCR approach, we assessed the methylation status of the CpG island of MGMT in 92 glioma patients who received temozolomide as first-line chemotherapy or as treatment for relapses. RESULTS: Methylation of the MGMT promoter positively correlated with the clinical response in the glioma patients receiving temozolomide as first-line chemotherapy (n = 40). Eight of 12 patients with MGMT-methylated tumors (66.7%) had a partial or complete response, compared with 7 of 28 patients with unmethylated tumors (25.0%; P = 0.030). We also found a positive association between MGMT methylation and clinical response in those patients receiving BCNU (n = 35, P = 0.041) or procarbazine/1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (n = 17, P = 0.043) as first-line chemotherapy. Overall, if we analyze the clinical response of all of the first-line chemotherapy treatments with temozolomide, BCNU, and procarbazine/1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea as a group in relation to the MGMT methylation status, MGMT hypermethylation was strongly associated with the presence of partial or complete clinical response (P < 0.001). Finally, the MGMT methylation status determined in the initial glioma tumor did not correlate with the clinical response to temozolomide when this drug was administered as treatment for relapses (P = 0.729). CONCLUSIONS: MGMT methylation predicts the clinical response of primary gliomas to first-line chemotherapy with the alkylating agent temozolomide. These results may open up possibilities for more customized treatments of human brain tumors.

Distinct responses of xenografted gliomas to different alkylating agents are related to histology and genetic alterations.

A series of 12 human gliomas was established as xenografts in nude mice and used to evaluate the relationship between histology, genetic parameters, and response to alkylating agents. Eight were high-grade oligodendroglial tumors, and four were glioblastoma. They were characterized for their genetic alterations, including those considered as "early" alterations, namely loss of chromosome 1 +/- loss of chromosome 19q, TP53 mutation, and those considered as "late" alterations, namely loss of chromosome 10, loss of chromosome 9p, EGFR genomic amplification, PTEN mutation, CDKN2A homozygous deletion, and telomerase reactivation. Chemosensitivity of xenografts to four alkylating agents, temozolomide (42 mg/kg, days 1-5, p.o.), 1,3-bis(2-chloroethyl)-1-nitrosourea (5 mg/kg, day 1, i.p.), Ifosfamide (90 mg/kg, days 1-3, i.p.), and carboplatin (66 mg/kg, day 1, i.p.) was tested by administration of drugs to tumor-bearing mice. Although each tumor presented an individual response pattern, glioblastoma had a lower chemosensitivity than oligodendrogliomas, and temozolomide was the most effective drug. Deletion of 1p +/- 19q was associated with higher chemosensitivity, whereas late molecular alterations, particularly EGFR amplification, were associated with chemoresistance. These results suggest that the combined use of histology and molecular markers should eventually be helpful selecting the most appropriate agents for treatment of malignant oligodendrogliomas and astrocytomas.

Analysis of the bHLH transcription factors Olig1 and Olig2 in brain tumors.

In the absence of specific markers, the histological diagnosis of oligodendroglial tumors is based on subjective qualitative criteria and remains controversial. Recently, two bHLH transcription factors involved in oligodendroglial specification, Olig1 and Olig2 have been proposed as potential markers of oligodendrogliomas. Expression of Olig1/2 was analyzed by in situ hybridization on 78 samples including 47 glial, 29 non-glial tumors, and two non-tumoral brain tissues. Both genes had a similar pattern of expression. Olig1 and Olig2 were expressed in 26/30 (87%) and 28/30 (93%) of oligodendroglial tumors respectively but in only 9% of glioblastomas (1/11). Olig genes were also expressed in the low-grade fibrillary astrocytomas (4/4) and anaplastic astrocytomas (2/2). No expression was found in non-glial tumors, except for one primary cerebral lymphoma. Double staining with PLP, NFH, GFAP showed that olig genes were expressed by mature, non-tumoral oligodendrocytes, but not by normal astrocytes or neurones. This study indicates that Olig1/2 expression clearly distinguishes pure Olig-negative glioblastomas from a wide spectrum of Olig-positive tumors including traditional oligodendrogliomas and oligoastrocytomas, glioblastomas with an oligodendroglial component (GBMO), and WHO grade 2 and 3 astrocytomas. Because Olig genes have a crucial role in oligodendroglial determination, our data could be of help in defining the real spectrum of oligodendroglial tumors.

Loss of 14q chromosome in oligodendroglial and astrocytic tumors.

Loss of chromosome 14q has been investigated in 142 gliomas. Loss of heterozygosity (LOH) at one or more microsatellite has been found in 8/30 grade II (27%) and 2/21 grade III (10%) oligodendrogliomas, 3/9 grade II (33%) and 5/15 grade III (33%) oligoastrocytomas, 0/9 grade II (0%) and 1/7 grade III (14%) astrocytomas, 11/51 glioblastomas (22%). Two minimal regions were identified on 14q21.2-14q24.3 (between D14S288 and D14S74) and 14q31.3-14q32.1 (between D14S74 and D14S65). Loss of 14q was not correlated to survival, histological grading and subtype or other genetic alterations, except for 1p deletions. Taken together, these data suggest that LOH14q is an early alteration involving 20% of glioma.

Prognostic value of allelic losses and telomerase activity in meningiomas.

OBJECT: The goal of this study was to examine allelic losses and telomerase activity in meningiomas to determine whether they could be used to predict disease recurrence. METHODS: To identify predictive markers of recurrence, a cohort of high-grade (24 World Health Organization [WHO] Grade II and six WHO Grade III) and low-grade (21 WHO Grade I) meningiomas was investigated for losses of heterozygosity (LOHs) on chromosomes 1p, 9p, 10q, 14q, and 22q, a deletion of CDKN2A, and telomerase activity. Results of molecular analyses were compared with radiological and histological findings and progression-free survival (PFS). Losses of heterozygosity on chromosomes 22q, 1p, and 10q, as well as telomerase activity were related to the WHO histological grades of the lesions (p < 0.01, p < 10(-5), p < 10(-4), and p = 0.002, respectively). In the absence of an LOH on 22q, the other alterations were found infrequently. Overall, the number of molecular alterations was closely related to the histological grades of the lesions (p < 10(-6)). An LOH on 22q occurred much more frequently in convexity or falx (33 [87%] of 38 lesions) than in skull base or spinal meningiomas (four [31%] of 13 lesions) (p < 0.001). The histological grade; Simpson grade; an LOH on chromosome 1p, 9p, or 10q; and telomerase activity were correlated with a shorter PFS time (p < 10(-4), p = 0.02, p = 0.000365, p = 0.022, p = 0.00027, and p = 0.000512, respectively). CONCLUSIONS: On the basis of these data the authors suggest that LOH analysis and a telomerase activity assay could be useful to determine molecular predictors of outcome in patients with meningiomas.