Irune Ruiz

A small noncoding RNA signature found in exosomes of GBM patient serum as a diagnostic tool

BACKGROUND Glioblastoma multiforme (GBM) is the most frequent malignant brain tumor in adults, and its prognosis remains dismal despite intensive research and therapeutic advances. Diagnostic biomarkers would be clinically meaningful to allow for early detection of the tumor and for those cases in which surgery is contraindicated or biopsy results are inconclusive. Recent findings show that GBM cells release microvesicles that contain a select subset of cellular proteins and RNA. The aim of this hypothesis-generating study was to assess the diagnostic potential of miRNAs found in microvesicles isolated from the serum of GBM patients. METHODS To control disease heterogeneity, we used patients with newly diagnosed GBM. In the discovery stage, PCR-based TaqMan Low Density Arrays followed by individual quantitative reverse transcriptase polymerase chain reaction were used to test the differences in the miRNA expression levels of serum microvesicles among 25 GBM patients and healthy controls paired by age and sex. The detected noncoding RNAs were then validated in another 50 GBM patients. RESULTS We found that the expression levels of 1 small noncoding RNA (RNU6-1) and 2 microRNAs (miR-320 and miR-574-3p) were significantly associated with a GBM diagnosis. In addition, RNU6-1 was consistently an independent predictor of a GBM diagnosis. CONCLUSIONS Altogether our results uncovered a small noncoding RNA signature in microvesicles isolated from GBM patient serum that could be used as a fast and reliable differential diagnostic biomarker.

Mutations in Progranulin Gene: Clinical, Pathological, and Ribonucleic Acid Expression Findings

BACKGROUND There is an increasing interest in the clinico-pathological correlation of mutations in progranulin (PGRN) and frontotemporal lobar degeneration (FTLD) complex diseases. We aim to study the PGRN expression variability in patients with different clinical features for a better understanding of its roles in FTLD disease. METHODS We sequenced the PGRN gene in 72 patients suffering from FTLD (25 familial and 47 sporadic cases) and in 24 asymptomatic at-risk relatives. We also analyzed PGRN expression in blood by quantitative real-time polymerase chain reaction from 37 patients, 8 asymptomatic mutation carriers, and 10 control subjects as well as in brain tissue from 16 patients and 9 control subjects. RESULTS Four novel mutations were associated with familial and sporadic FTLD and familial dementia associated with amyotrophic lateral sclerosis. We identified a close association between the IVS6-1G>A mutation in PGRN and corticobasal syndrome. Brain tissue was available for carriers of two of the four mutations (IVS6-1 G>A and P357HfsX3). Immunohistochemical analysis revealed ubiquitin- and TDP-43positive and tau/alpha-synuclein negative immunoreactive neuronal intranuclear inclusions. The relative expression of PGRN in the clinical sample was significantly lower in carriers of the IVS6-1 G>A than in control subjects. CONCLUSIONS Progranulopathies are a major cause of the main phenotypes included in the FTLD complex. According to our results, the level of expression of PGRN in blood could be a useful marker both for diagnostics of part of the spectrum of FTLD conditions and for monitoring future treatments that might boost the level of PGRN in this disorder.

Neuropathology of Parkinson's Disease with the R1441G Mutation in LRRK2

We report the neuropathological findings in a patient with Parkinsons disease (PD) associated with Basque R1441G‐LRRK2/dardarin mutation. The patient was a man with disease onset at 68 years of age, with unilateral rest tremor; the Parkinsonism was well controlled with medication for 15 years. He died at the age of 86, after 18 years of evolution. The neuropathological examination disclosed mild neuronal loss in the substantia nigra pars compacta without α‐synuclein, tau, LRRK2, or ubiquitin cytoplasmic inclusions. Lewy bodies and Lewy neurites were absent. This is the first neuropathological study of PD associated with brain with the R1441G mutation in LRRK2.

A Novel PRNP Y218N Mutation in Gerstmann-Straussler-Scheinker Disease With Neurofibrillary Degeneration

Gerstmann-Sträussler-Scheinker (GSS) disease is a prion disease associated with prion protein gene (PRNP) mutations. We report a novel PRNP mutation (Y218N) associated with GSS disease in a pathologically confirmed case and in two other affected family members. The clinical features of these cases met criteria for possible Alzheimer disease and possible frontotemporal dementia. Neuropathologic analysis revealed deposition of proteinase K-resistant prion protein (PrPres), widespread hyperphosphorylated tau pathology, abnormal accumulation of mitochondria in the vicinity of PrPres deposits, and expression of mutant ubiquitin (UBB+1) in neurofibrillary tangles and dystrophic neurites. Prion protein immunoblotting using 3F4 and 1E4 antibodies disclosed multiple bands ranging from approximately 20 kd to 80 kd and lower bands of 15 kd and approximately 10 kd, the latter only seen after a long incubation. These bands were partially resistant to proteinase K pretreatment. This pattern differs from those seen in Creutzfeldt-Jakob disease andresembles those reported in other GSS cases. The approximately 10kd band was recognized with anti-PrP C-terminus antibodies but not with anti-N terminus antibodies, suggesting PrP truncation at the N terminal. This new mutation extends the list of known mutations responsible for GSS disease and reinforces its clinical heterogeneity. Genetic examination of the PRNP gene should be included in the workup of patients with poorly classifiable dementia.

Cerebrotendinous xanthomatosis: neuropathological findings.

Cerebrotendinous xanthomatosis is an inherited autosomal recessive lipid storage disease caused by a 27-hydroxylase enzyme deficiency, characterised clinically by tendon xanthomas, premature cataracts, chronic diarrhoea and progressive neurologic dysfunction. The disease is very uncommon and there are very few pathological descriptions. We report a 52-year-old male who presented with a neuropsychiatric disorder and cognitive decline. Despite treatment the patient developed optic atrophy, parkinsonism and dementia and died. The autopsy revealed a nonspecific brain and cerebellar atrophy.Under microscopic examination, lipid crystal clefts, neuronal loss, demyelination, reactive astrocytosis and perivascular macrophages were found. These findings suggest the limited reversibility of the disease, and its poor prognosis, specially if treatment is not started early.

mTOR inhibition decreases SOX2-SOX9 mediated glioma stem cell activity and temozolomide resistance

ABSTRACT Background: SOX2 and SOX9 are commonly overexpressed in glioblastoma, and regulate the activity of glioma stem cells (GSCs). Their specific and overlapping roles in GSCs and glioma treatment remain unclear. Methods: SOX2 and SOX9 levels were examined in human biopsies. Gain and loss of function determined the impact of altering SOX2 and SOX9 on cell proliferation, senescence, stem cell activity, tumorigenesis and chemoresistance. Results: SOX2 and SOX9 expression correlates positively in glioma cells and glioblastoma biopsies. High levels of SOX2 bypass cellular senescence and promote resistance to temozolomide. Mechanistic investigations revealed that SOX2 acts upstream of SOX9. mTOR genetic and pharmacologic (rapamycin) inhibition decreased SOX2 and SOX9 expression, and reversed chemoresistance. Conclusions: Our findings reveal SOX2-SOX9 as an oncogenic axis that regulates stem cell properties and chemoresistance. We identify that rapamycin abrogate SOX protein expression and provide evidence that a combination of rapamycin and temozolomide inhibits tumor growth in cells with high SOX2/SOX9.

Targeting SOX2 as a Therapeutic Strategy in Glioblastoma

Glioblastoma is the most common and malignant brain cancer in adults. Current therapy consisting of surgery followed by radiation and temozolomide has a moderate success rate and the tumor reappears. Among the features that a cancer cell must have to survive the therapeutic treatment and reconstitute the tumor is the ability of self-renewal. Therefore, it is vital to identify the molecular mechanisms that regulate this activity. Sex-determining region Y (SRY)-box 2 (SOX2) is a transcription factor whose activity has been associated with the maintenance of the undifferentiated state of cancer stem cells in several tissues, including the brain. Several groups have detected increased SOX2 levels in biopsies of glioblastoma patients, with the highest levels associated with poor outcome. Therefore, SOX2 silencing might be a novel therapeutic approach to combat cancer and particularly brain tumors. In this review, we will summarize the current knowledge about SOX2 in glioblastoma and recapitulate several strategies that have recently been described targeting SOX2 in this malignancy.

Cancer risk in DM1 is sex-related and linked to miRNA-200/141 downregulation

Objective: Describe the incidence of cancer in a large cohort of patients with myotonic dystrophy type 1 (DM1) and to unravel the underlying molecular mechanisms. Methods: Standardized incidence ratios (SIRs) were calculated in the Gipuzkoa DM1 cohort (1985–2013), dividing observed numbers by expected numbers for all cancers combined and stratified by sex. An estimation of the expected incidence was achieved by multiplying the age- and sex-specific incidence rates from the Basque population cancer registry by the person-years observed in the study cohort. Large-scale gene expression of peripheral blood mononuclear cell samples derived from 10 individuals with DM1 (5 men, 5 women) and 10 healthy matched controls was analyzed by the Human Gene 1.0 ST Affymetrix microarray. Results: During 18,796 person-years of follow-up, corresponding to 424 patients with DM1, we observed 70 cancers in 62 patients giving a 1.81-fold risk (95% confidence interval [CI] 1.37–2.36), which was stronger in women than in men. Ovary (SIR 8.33, 95% CI 1.72–24.31) and endometrium (SIR 6.86, 95% CI 2.23–16.02) in women and thyroid (SIR 23.33, 95% CI 9.38–48.08) and brain (SIR 9.80, 95% CI 3.18–22.88) in both sexes were tumor sites with significantly higher risks in DM1. There were differences in gene expression between healthy controls and patients with DM1 and between men and women with DM1; all patients with DM1 combined and female patients with DM1 displayed significant downregulation of the microRNA (miRNA)-200c/141 tumor suppressor family. Conclusions: Oncologic risk is increased in DM1, especially in women and for gynecologic, brain, and thyroid cancer. Expression of the miRNA-200/miRNA-141 tumor suppressor family is decreased in women with DM1.

Therapeutic strategies targeting glioblastoma stem cells.

Glioblastoma is the most common, aggressive and lethal brain tumor in adults. However, current therapeutic protocols have low success rates and average overall survival is less than 15 months. The resistance to therapy is largely a result of the remarkable cellular and phenotypical heterogeneity that characterizes this type of tumor. The discovery of a subpopulation of cells exhibiting stem cell properties within the tumor bulk has profound implications for therapy as increasing evidence indicates that these cells, glioblastoma stem cells (GSCs), are responsible for the origin, maintenance and recurrence of the glioblastomas. These findings highlight the need to characterize GSCs in order to find novel treatments directly targeted specifically against them. In this review, we summarize the current knowledge regarding this issue, including some recent and relevant patents.

Funciones y organización de un comité de neurooncología en un hospital con servicio de neurocirugía

The Neuro-Oncology Study Group (NOSG) at SENEC has commissioned the elaboration of the present document to the Neuro-Oncology Committee at Donostia University Hospital. It is intended to serve as a NOSG Consensus Guide and a proposed recommendation for the management of this pathological condition at all Spanish Hospitals, both public and private. Neuro-Oncology Committees must be established and active at all centres with a Neurosurgery Service, taking into account the specific diagnostic and therapeutic capacity available. The work presents an example of the constitution, functioning and experience of such a Committee, drawing on 8 years of multidisciplinary work with brain tumour patients.