Myxoid glioneuronal tumor (MGT) is a benign glioneuronal neoplasm recently introduced in the World Health Organization (WHO) classification of the central nervous system (CNS) tumors. MGTs are ...typically located in the septum pellucidum, foramen of Monro or periventricular white matter of the lateral ventricle. They were previously diagnosed as dysembryoplastic neuroepithelial tumors (DNT), showing histological features almost indistinguishable from classical cortical DNT. Despite that, MGTs have been associated with a specific dinucleotide substitution at codon 385 in the platelet-derived growth factor receptor alpha (PDGFRA) gene, replacing a lysine residue with either leucine or isoleucine (p. LysK385Leu/Iso). This genetic variation has never been described in any other CNS tumor.
Thirty-one consecutive tumors, previously diagnosed as DNTs at the Meyer Children's Hospital IRCCS between January 2010 and June 2021 were collected for a comprehensive study of their clinical, imaging, pathological features, and molecular profile.
In six out of the thirty-one tumors we had previously diagnosed as DNTs, we identified the recurrent dinucleotide mutation in the PDGFRA. All six tumors were typically located within the periventricular white matter of the lateral ventricle and in the septum pellucidum. We then renamed these lesions as MGT, according to the latest WHO CNS classification. In all patients we observed an indolent clinical course, without recurrence.
MGT represent a rare but distinct group of neoplasm with a typical molecular profiling, a characteristic localization, and a relative indolent clinical course.
Morquio A syndrome (MPS IVA) is a recessive lysosomal storage disorder (LSD) caused by mutations in the GALNS gene leading to the deficiency of lysosomal enzyme N-acetylgalactosamine-6-sulfate ...sulfatase (GALNS). Patients show a broad spectrum of phenotypes ranging from classical severe type to mild forms. Classical forms are characterized by severe bone dysplasia and usually normal intelligence. So far, more than 170 unique mutations have been identified in the GALNS gene of MPS IVA patients.
We report on a Morquio A patient with a classical phenotype who was found to be homozygous for a missense mutation (c.236G>A; p.Cys79Tyr) in the GALNS gene. This alteration affects the highly conserved p.Cys79 that is transformed into formylglycine, the catalytic residue of the active site. The mutation was present in the proband's mother, but not in the father, whose paternity was confirmed by microsatellite analysis. In order to test the hypothesis of maternal uniparental disomy (UPD), we investigated the segregation of sixteen microsatellite markers from chromosome 16. The results showed a condition of maternal UPD due to an error in meiosis I. Maternal isodisomy of the 16q24 region led to homozygosity for the GALNS mutant allele, causing the patient's disease. These findings allow to add for the first time the LSD Morquio A syndrome to the list of conditions that can be caused by UPD. The possibility of UPD is relevant when giving genetic counseling to couples since the recurrent risk in future pregnancies is dramatically reduced.
► First case of Lysosomal Storage Disease due to Maternal Uniparental Isodisomy. ► First case reported homozygote for p.Cys79Tyr mutation affecting GALNS active site. ► The possibility of UPD has relevant implications for genetic counseling.
Identification of the genetic defect underlying early-onset diabetes is important for determining the specific diabetes subtype, which would then permit appropriate treatment and accurate assessment ...of recurrence risk in offspring. Given the extensive genetic and clinical heterogeneity of the disease, high-throughput sequencing might provide additional diagnostic potential when Sanger sequencing is ineffective. Our aim was to develop a targeted next-generation assay able to detect mutations in several genes involved in glucose metabolism. All 13 known MODY genes, genes identified from a genome-wide linkage study or genome-wide association studies as increasing the risk of type 2 diabetes and genes causing diabetes in animal models, were included in the custom panel. We selected a total of 102 genes by performing a targeting re-sequencing in 30 patients negative for mutations in the GCK, HNF1α, HNF4α, HNF1β and IPF1 genes at the Sanger sequencing analysis. Previously unidentified variants in the RFX6 gene were found in three patients and in two of them we also detected rare variants in WFS1 and ABCC8 genes. All patients showed a good therapeutic response to dipeptidyl peptidase-4 (DPP4) inhibitors. Our study reveals that next-generation sequencing provides a highly sensitive method for identification of variants in new causative genes of diabetes. This approach may help in understanding the molecular etiology of diabetes and in providing more personalized treatment for each genetic subtype.
A prerequisite for the efficacy of chemotherapy is that it reaches the tumor mass at a therapeutic concentration. In brain tumors this phenomenon is hampered by the presence of the blood brain ...barrier (BBB) which limits the spread of chemotherapeutic agents within the brain. It is lately emerged as this Multi Drug Resistance (MDR) phenomenon is explained through the cooperation of P-glycoprotein (P-gp, ABCB1) and breast cancer resistance protein (BCRP, ABCG2), two "gatekeeper" transporters that work in tandem on the BBB and are also present on the plasma membrane of certain brain tumors. Recently, we have attempted to improve the therapeutic efficacy of pharmacological treatment in malignant brain tumors by safe and temporary BBB permeabilization. We have demonstrated that morphine and, to a lower level, ondansetron and dexamethasone allow an accumulation of doxorubicin within the rat brain by LC-MS/MS mass spectrometry. All these drugs are substrates of P-gp and BCRP efflux pumps. The aim of the current proposal is to expand our preliminary observation, to understand the mechanism of action of BBB "permeabilization" induced by morphine or other drugs, and to exploit this method for the "treatment" of brain tumour in an animal model. i) Quantifying the level drugs that do not usually cross the BBB (mitoxantrone or melphalan) after morphine pre-treatment in a preclinical model. Verifying the cytotoxic effect of morphine plus doxorubicin (and other chemotherapeutic agents) treatment by using MTT and TUNEL analysis in glioblastoma cell lines ii) Quantifying the level of drugs that do not usually cross the BBB after morphine pre-treatment in an artificial BBB through a monolayer of MDCKII cells over-expressing the human P-gp or BCRP. iii) Investigating the regulatory role of certain microRNA in MDR mechanism by RT-PCR and western blot analysis of P-gp, BCRP, miR-21, miR-27a and miR-451. Our data suggest that blocking efflux transporters by pretreatment with morphine, ondansetron or desamethasone is able to allow doxorubicin penetration inside the brain. This is not associated with acute cardiac or renal toxicity. These preliminary results will enable us to novel therapeutic approaches to refractory or recurrent brain tumors in which molecules usually stopped by the BBB may have a therapeutic impact.
Introdution:
Li-Fraumeni Syndrome (LFS) is an cancer susceptibility condition, characterized by an autosomal dominant transmission that increases an individuals risk of developing early synchronous ...and metachronous primary tumors. Classic LFS is associated with the development of sarcomas, diagnosed before 45 years of age with a first-degree relative with cancer before 45 years of age, and another close (first- or second-degree relative) with any cancer diagnosed under 45 years of age or with sarcoma at any age. The typical tumors include breast carcinoma, osteosarcoma soft tissue sarcomas, adrenocortical carcinoma (ACC), leukemias, CNS tumors and lung cancer. Classic LFS has an approximate frequency of 70% compare to whole cancer-predisposition syndromes. The only gene that has been consistently associated with LFS is TP53.
Materials and Methods:
In 1998 a 16-month-old female was evaluated for early puberty. Abdominal ultrasound demonstrated a lesion located at adrenal gland. The patient was subjected to resection of an ACC followed by therapy with mitotane and corticosteroid. In December 2014, the patient was admitted to our Hospital for an episode of loss of consciousness with generalized epileptic episodes. Cranial TC scans showed a right parietal lesion which was subsequently confirmed by a brain MRI. The patient underwent gross total removal of the lesion, without complications and good neurological improvement.
Results:
The histopathological diagnosis was gliosarcoma (WHO-grade IV).Cerebrospinal fluid (CSF) cytology was negative. The patient underwent radiotherapy for a total dose of 59,4 Gy (1.8 Gy/fraction) given with Volumetric Modulated Arc Therapy (VMAT). The radiotherapy was associated with concomitant and sequential chemotherapy with temozolomide, vinorelbine and valproic acid. The patient remains alive without evidence of recurrent disease 30 months after starting chemotherapy. She maintains a Karnofsky Performance Score of greater than 90. At the beginning oncologic family history was negative. After 5 years from this diagnosis, her father died from a leiomyosarcoma at the age of 40. In 2013 her brother died at 19-year-old from an acute myeloid leukemia. Interestingly, the paternal grandmother died at 60-year-old due to melanoma after a previously having breast cancer. The family history supported such a LFS. TP53 gene analysis of our patient showed the germ-line mutation c.796G>A (p.Gly266Arg) in heterozygous.
Conclusion:
The description of this case highlights the importance of a correct clinical monitoring of patients with LFS for the high risk of cancer. A brain MRI every 6 months starting from 18 years of age is essential; indeed it was reported that 10% of LFS patients with develops a glioma before age 45 and 5% develops a PNET (primitive neuroectodermal tumors), a medulloblastoma, a choroid plexus carcinoma or an ependymoma.
Introduction:
Pediatric high-grade gliomas (HGGs) represent a malignancy with a low survival rate. The genetic analysis of these tumors has identified useful mutations for an improved prognostic ...framing, as well as potential targets for new generation drugs. Previous studies have shown that the presence of BRAF V600E mutation in 23% of all pediatric gliomas reaching about 10% in WHO-grades III and IV, suggesting this alteration is one of the most common gene alterations in pediatric gliomas. BRAF mutation may help to differentiate indolent cancer from aggressive ones; tumors with BRAF V600E have a strong trend toward an increased risk for progression, developing a second cancer with anaplastic evolution. Moreover, BRAF mutation is a possible target for improved adjuvant treatment of residual or recurrent tumors.
Materials and Methods:
We performed a retrospective analysis of a population of pediatric patients with HGGs. Mutation analysis was carried out on DNA from each tumor sample. Portions coding and their flanking regions were amplified by PCR. The data were obtained after the purification of the samples and analysis by means of specific software.
Results:
We retrospectively evaluated 41 cases of pediatric HGGs. The median age at diagnosis was 7 years (range 0-32). The histological samples included: 9 cases of glioblastoma multiforme, 28 cases of anaplastic astrocytoma (AA), 3 glioneuronal tumor with neuropil-like islands (GTNI) and 1 glioma with mist components (2,45%). BRAF V600E mutation was analyzed in 27 samples: 21 patients did not have the mutation (77.77%), 6 patients showed the mutation (22,22). Four of 6 AA patients derived from a previous low grade tumor (3LGGs, and 1 GTNI) (p: 0.001). The BRAF V600E mutation seems therefore associated with increased risk of anaplastic progression. Finally, we have valuated the correlation between the presence of BRAF mutation and the tumor histology without statistically significant results (p: 0.12).
Conclusions:
The genetic analysis of tumor samples from children with HGGs represents an essential contribution to the prognostic stratification for each new diagnosis. BRAFV600E mutation is a negative prognostic factor in pediatric gliomas and a potential target of specific inhibitors. Considering the high rate of recurrence of these tumors and the limited impact on disease control of the following treatments, BRAF V600E detection is essential for a new therapeutic approach of poor responsive diseases.
Abstract
Background
Glioblastoma (GBM) is the most common primary brain tumor with a poor prognosis, characterized by a high cellular heterogeneity and invasiveness. Multi-drug resistance (MDR), the ...blood brain barrier (BEE) and DNA repair systems let the survival of tumor cells, making the treatment with chemo and radiotherapy not effective. Autophagy is a physiological mechanism that allows the recycling of damaged proteins and organelles, in order to protect the correct cell turnover. However, in GBM this process promotes survival and proliferation in stressful conditions such as after a chemo and / or radiotherapy treatment. The Hippo pathway is an extremely important molecular signaling because it is involved in various tumorigenesis processes, for instance the epithelium-mesenchymal transition (EMT), in the increase of stemness, mechanotransduction and chemoresistance.
Material and Methods
The modulation of autophagy was evaluated in GBM cell lines (U87MG, T98G and A172) exploiting a fluorescent detection that allowed the quantification of the autophagosomal activity present into the cell lines. The rate of autophagy was assessed after the cell lines pharmacological treatment with Hippo pathway inhibitors, Verteporfin 2uM (VP) for 24h, Latrunculin 0,5uM (LAT) for 3h and Cytochalasin 1uM (CIT) for 3h, with Doxorubicin 0,5uM (DOX) for 24h and with the drugs combination (DOX-VP, DOX-LAT and DOX-CIT). Moreover, the expression of the autophagy marker LC3II / I was evaluated in all three GBM cell lines by Western Blotting (WB) experiments. To perform this technique, the cells were treated with DOX and Hippo pathway inhibitors respecting the pharmacological treatment previously used. Then, the proteins were extracted, quantified and finally the WB was performed.
Results
The results obtained showed that the three GBM cell lines without any drugs were marked by high levels of autophagy, similar to the cells treated with Rapamycin, an autophagy inducer. Moreover, the autophagy rate was definitely reduced after treatment with VP and DOX-VP in all three cell lines, including the chemoresistant T98G. Conversely, the other two Hippo pathway inhibitors (LAT-CIT) and DOX did not significantly change the rate of autophagy. The expression of LC3II / I was particularly low after treatment with VP and DOX-VP in all three cell lines while the other two inhibitors did not significantly change its expression.
Conclusion
In conclusion, these data demonstrated that the three GBM cell lines (U87MG, T98G and A172) are characterized by high levels of autophagy and the inhibition of the Hippo pathway with VP and especially the combination DOX-VP reduced the activation of this protumoral molecular mechanism in GBM cell lines.
Aims.
We aim to search for a hidden leptonic accelerator, such as a high-
Ė
pulsar, associated with the unidentified TeV object HESS J1702−420A.
Methods.
We carried out a 72 ks X-ray observation with ...the
XMM-Newton
satellite and analyzed the resulting data jointly with the publicly available HESS spectral energy distribution (SED) results to derive constraints on the leptonic contribution to the TeV emission of HESS J1702−420A. A set of scripts dedicated to the multi-wavelength modeling of X-ray and
γ
-ray data, based on
Gammapy
,
Naima
, and
Xspec
, has been developed in the context of this work and made publicly available along with this paper.
Results.
No object clearly associated with HESS J1702−420A was found in the
XMM-Newton
data. After excluding the unidentified object Suzaku src B as a possible X-ray counterpart and classifying it as a new cataclysmic variable source candidate, we derived strict upper limits on the level of diffuse X-ray emission in the HESS J1702−420A region:
F
(2 − 10 keV)≲5.4 × 10
−5
keV cm
−2
s
−1
at 2
σ
(≈95.5%) confidence level. A tight constraint on the magnetic field was derived, under a one-zone leptonic scenario, by jointly fitting the
XMM-Newton
spectra and the HESS SED:
B
≲ 1.45 μG at 2
σ
level. We additionally report the serendipitous discovery of a new extended X-ray source with a hard spectral index of 1.99 ± 0.45, named XMMU J170147.3−421407 which is likely Galactic. Its classification as a high-speed runaway pulsar wind nebula (PWN), possibly associated with HESS J1702−420A, is not obvious but cannot be ruled out either.
Conclusions.
The hard
γ
-ray object HESS J1702−420A remains unidentified, but the absence of a clear X-ray counterpart strongly challenges simple leptonic scenarios. The only remaining possible leptonic counterpart for HESS J1702−420A appears to be a newly discovered X-ray source with extended morphology and hard spectral index, which may be a PWN powered by a high-speed runaway pulsar.
Abstract
BACKGROUND
Glioblastoma (GBM) is a primary human malignant brain tumor, the most common in adults. Several studies have highlighted the Hippo-pathway as a cancer signalling network. The ...Hippo pathway is an evolutionarily conserved signal cascade, which is involved in the control of organ growth. Dysregulations among this pathway have been found in lung, ovarian, liver and colorectal cancer. The key downstream effector of the Hippo-pathway is the Yes-associated protein (YAP); in the nucleus, its function as transcription co-activator is to interact with transcription factors, resulting in the expression of target genes involved in pro-proliferating and anti-apoptotic programs.
MATERIAL AND METHODS
Using western blotting analysis, we determined the nuclear expression of YAP on three GBM cell lines (U87MG, T98G and A172). To investigate which inhibitors against the Hippo-pathway were the most efficient, we performed a cytotoxic assay: we treated all the three cell lines with different inhibitors such as Verteporfin (VP), Cytochalasin D (CIT), Latrunculin A (LAT), Dobutamine (DOB) and Y27632. Afterwards, we performed a treatment using Doxorubicin (DOX) combined with the inhibitors, evaluating its cytotoxic effect on our cell lines, through cell viability experiments. More western blotting experiments were performed to investigate the oncogenic role of YAP at nucleus level. Furthermore, preliminary experiments have been conducted in order to investigate the apoptosis, senescence and autophagy modulation due to the Hippo-pathway.
RESULTS
We showed our cell lines express nuclear YAP. We assessed the efficiency of the main inhibitors against Hippo-pathway, proving that VP, LAT A and CIT show a strong cytostatic effect, linked to time increase; plus we saw a cytotoxic effect on T98G. The association of DOX with selected inhibitors is able to reduce cell viability and nuclear YAP expression rate in all three GBM lines. Finally, preliminary experiments were set up to assess how and if the mechanisms of apoptosis, autophagy and senescence were affected by the Hippo-pathway. The combination of DOX with inhibitors promotes resistance to apoptosis.
CONCLUSION
Our results show that nuclear YAP is present in all tumor lines, thus confirming that this molecular pathway is functioning in GBM lines. Nuclear YAP is more highly expressed after DOX administration. Moreover, the combined treatment (DOX with Hippo-pathway inhibitors) reduces both cell proliferation and viability, and increases the rate of apoptosis. Preliminary experiments on senescence and autophagy were used to determine the best Hippo-pathway inhibitor. These data demonstrate that the Hippo-pathway plays a crucial role in GBM proliferation and resistance to apoptosis. Inhibiting this pathway and in particular the transcription factor YAP, in association with DOX, might be an excellent therapeutic target.
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