Tyrphostin A9 attenuates glioblastoma growth by suppressing PYK2/EGFR-ERK signaling pathway.

PURPOSE: Glioblastoma (GBM) is a fatal primary brain tumor with extremely poor clinical outcomes. The anticancer efficiency of tyrosine kinase inhibitors (TKIs) has been shown in GBM and other cancer, with limited therapeutic outcomes. In the current study, we aimed to investigate the clinical impact of active proline-rich tyrosine kinase-2 (PYK2) and epidermal growth factor receptor (EGFR) in GBM and evaluate its druggability by a synthetic TKI-Tyrphostin A9 (TYR A9). METHODS: The expression profile of PYK2 and EGFR in astrocytoma biopsies (n = 48) and GBM cell lines were evaluated through quantitative PCR, western blots, and immunohistochemistry. The clinical association of phospho-PYK2 and EGFR was analyzed with various clinicopathological features and the Kaplan-Meier survival curve. The phospho-PYK2 and EGFR druggability and subsequent anticancer efficacy of TYR A9 was evaluated in GBM cell lines and intracranial C6 glioma model. RESULTS: Our expression data revealed an increased phospho-PYK2, and EGFR expression aggravates astrocytoma malignancy and is associated with patients' poor survival. The mRNA and protein correlation analysis showed a positive association between phospho-PYK2 and EGFR in GBM tissues. The in-vitro studies demonstrated that TYR A9 reduced GBM cell growth, cell migration, and induced apoptosis by attenuating PYK2/EGFR-ERK signaling. The in-vivo data showed TYR A9 treatment dramatically reduced glioma growth with augmented animal survival by repressing PYK2/EGFR-ERK signaling. CONCLUSION: Altogether, this study report that increased phospho-PYK2 and EGFR expression in astrocytoma was associated with poor prognosis. The in-vitro and in-vivo evidence underlined translational implication of TYR A9 by suppressing PYK2/EGFR-ERK modulated signaling pathway. The schematic diagram displayed proof of concept of the current study indicating activated PYK2 either through the Ca2+/Calmodulin-dependent protein kinase II (CAMKII) signaling pathway or autophosphorylation at Tyr402 induces association to the SH2 domain of c-Src that leads to c-Src activation. Activated c-Src in turn activates PYK2 at other tyrosine residues that recruit Grb2/SOS complex and trigger ERK½ activation. Besides, PYK2 interaction with c-Src acts as an upstream of EGFR transactivator that can activate the ERK½ signaling pathway, which induces cell proliferation and cell survival by increasing anti-apoptotic proteins or inhibiting pro-apoptotic proteins. TYR A9 treatment attenuate GBM cell proliferation and migration; and induce GBM cell death by inhibiting PYK2 and EGFR-induced ERK activation.

Predictors of surgical outcome in focal cortical dysplasia and its subtypes.

OBJECTIVE: The authors analyzed predictors of surgical outcome in patients with focal cortical dysplasia (FCD) and its ILAE (International League Against Epilepsy) subtypes after noninvasive multimodal evaluation and calculated time to first seizure. METHODS: Data of 355 patients with refractory epilepsy, confirmed FCD pathology, and 2-13 years of postsurgical follow-up were analyzed to determine the predictive roles of clinical, EEG, imaging, and surgical factors that influence seizure freedom. RESULTS: The mean ± SD age at surgery was 20.26 ± 12.18 years. In total, 142 (40.0%) patients had daily seizures and 90 (25.3%) had multiple seizure types. MRI showed clear-cut FCD in 289 (81.4%) patients. Pathology suggested type I FCD in 27.3% of patients, type II in 28.4%, and type III in 42.8% of patients. At latest follow-up, 72.1% of patients were seizure free and 11.8% were seizure free and not receiving antiepileptic drugs. Among the subtypes, 88.8% of patients with type III, 69.3% with type II, and 50.5% with type I FCD were seizure free. Multiple seizure types, acute postoperative seizures (APOS), and type I FCD were predictors of persistent seizures, whereas type III FCD was the strongest predictor of seizure freedom. Type I FCD was associated with daily seizures, frontal and multilobar distribution, subtle findings on MRI, incomplete resection, and persistent seizures. Type II and III FCD were associated with clear-cut lesion on MRI, regional interictal and ictal EEG onset pattern, focal pattern on ictal SPECT, complete resection, and seizure freedom. Type III FCD was associated with temporal location, whereas type I and II FCD were associated with extratemporal location. Nearly 80% of patients with persistent seizures, mostly those with type I FCD, had their first seizure within 6 months postsurgery. CONCLUSIONS: Long-term seizure freedom after surgery can be achieved in more than two-thirds of patients with FCD after noninvasive multimodal evaluation. Multiple seizure types, type I FCD, and APOS were predictors of persistent seizures. Seizures recurred in about 80% of patients within 6 months postsurgery.

Overexpression of aryl hydrocarbon receptor (AHR) signalling pathway in human meningioma.

Aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor and involved in tumorigenesis of many cancers. However there are no reports on AHR in human meningioma. Therefore we examined the status of the AHR and its signalling molecules in human meningioma by using tumor biopsy samples and autopsy control meninges. We report the up regulation of AHR pathway genes like aryl hydrocarbon receptor nuclear translocator (ARNT), aldehyde dehydrogenase1family memberA3 (ALDH1A3), cytochrome P450, family1, subfamily A polypeptide1 (CYP1A1) and TCCD induced poly ADP ribose polymerase (TIPARP) gene expression in human meningioma. Further, AHR protein expression was found to be up regulated in all grades of human meningioma. We found that AHR localized in the nucleus for high grade anaplastic meningioma through immunohistochemical analysis. Since AHR signalling pathway was known to involve in inhibition of apoptosis in cancer cells, we evaluated the cyclophilin D levels which maintains mitochondrial permeability transition pore a critical event during apoptosis. We report that cyclophilin D levels were upregulated in all grades of human meningioma compared to control meninges. Finally we also evaluated c-Fos protein levels as its levels were regulated by AHR. Here we report that c-Fos protein levels were down regulated in all grades of human meningioma compared to control meninges. To sum-up we found that AHR signalling pathway components were upregulated, as the grade of the meningioma progresses from low to high grade, suggesting an important role of AHR signalling pathway in human meningioma.

Altered tryptophan metabolism in human meningioma.

Meningiomas are the neoplasms that arise from the arachnoid cells of the meninges. It was reported that cancer cells escape from immune system through the metabolism of an aromatic essential amino acid tryptophan (TRP) via Kynurenine (KYN) pathway. However, the role of TRP metabolites such as, 5-Hydroxy tryptophan (5-HTP), 5-Hydroxy tryptamine (5-HT), N-acetyl serotonin (NAS), Melatonin (MEL), KYN, N-acetyl tryptamine, 5-Hydroxy indole acetic acid (5-HIAA) and 5-Methoxy indole acetic acid is not yet evaluated in human meningioma. Therefore, in the current study we have evaluated the levels of TRP and its metabolites in the progression of human meningioma using tumor biopsy samples and autopsy control meninges with Reverse Phase-HPLC. We here report that TRP metabolism favors towards KYN pathway in human meningioma and it could be due to increased indoleamine 2,3-dioxygenase 2 levels as we found its m-RNA levels to be up regulated in human meningioma. We observed significant increase in KYN and 5HIAA levels and significant decrease in TRP, 5-HTP, 5-HT, NAS and MEL levels in meningioma compared to control meninges. Since TRP metabolites regulate inducible nitric oxide synthase (INOS) gene expression and thereby nitric oxide (NO) production, we have also evaluated the INOS and NO levels. The INOS and NO levels were up regulated in human meningioma. The present data corroborates with existing data on TRP metabolism in tumor progression and may serve to target TRP metabolism as a therapeutic intervention.

Outcome of surgery for temporal lobe epilepsy in adults - A cohort study.

INTRODUCTION: The aim of the current study was to evaluate the factors associated with post-operative outcome in patients with temporal lobe epilepsy (TLE) undergoing Surgery. METHODS: We analyzed data of 288 consecutive patients operated for drug-resistant TLE. All the patients had at least one year post surgery follow-up. Logistic regression model was used to evaluate the predictive value of different factors for outcome. RESULTS: The mean age at onset of epilepsy of the study population was 15.51 ± 9.79 years; whereas the mean age at surgery was 32.16 ± 9.45 years, with 125 (43.4%) women. The age at surgery was significantly lower in the patients with favourable outcome (30.26 ± 9.05 vs. 34.06 ± 9.85 years; p = 0.007). The mean duration of epilepsy with age of onset below 12 years was higher than the rest (19.84 ± 7.30 vs. 13.00 ± 8.45 years; p < 0.001). The histopathology showed hippocampal sclerosis in 203 (70.4%) of the patients; isolated focal cortical dysplasia was associated with unfavourable outcome (9.3% vs.2.6%; p = 0.036). The duration of follow up ranged from 1 to 10.3 years. Three patients died late in the follow up. At the last follow 73% were seizure free and Engel's favourable outcome was noted in 82%. Duration of epilepsy greater than ten years (ß = 6.997; 95%CI; 2.254-21.715; p = 0.01), younger age of onset of epilepsy (ß = 1.07; 95%CI; 1.014-1.132; p = 0.015) and acute post operative seizures (APOS) (ß = 4.761; 95%CI; 1.946-11.649; p = 0.001) were the predictors of unfavourable outcome. CONCLUSION: Following surgery for TLE, 73% were seizure free and Engel's favourable outcome was noted in 82%. The predictors of unfavourable outcome were younger age of onset, pronged duration and of epilepsy and APOS.

Atypical Neurocytoma: Dilemma in diagnosis and management.

BACKGROUND: Central neurocytoma is an uncommon benign tumor of the central nervous system. A section of these tumors have unusual aggressiveness and are termed as "atypical central neurocytomas," the definition of which is debated. Many studies in the available literature define them as tumors with elevated MIB-1 labeling index (MIB-1 LI) >2%, while some associate them with higher values of MIB-1 LI or those with histological atypical features. Newer parameters also have been identified and correlated with MIB-1 LI to differentiate atypical from benign neurocytoma cases. A recent analysis of the atypical neurocytoma cases with malignant behavior revealed their increased tendency of spread through the cerebrospinal fluid causing craniospinal axis dissemination. However, limited studies document the appropriate indications and usefulness of additional therapeutic modalities, such as upfront craniospinal irradiation (CSI) or adjuvant chemotherapy, in countering the aggressive behavior of such tumors. CASE DESCRIPTION: We present two such rare cases of atypical neurocytoma with elevated MIB-1 LI, of 3% and 4%, respectively, without histological atypia. Since there is insufficient evidence documenting advantages of any additional measures in the adjuvant management of atypical cases, both patients were treated with localized cranial radiotherapy alone, as per the evidence available in the literature currently. CONCLUSION: We propose that future studies must aptly redefine these atypical neurocytomas with malignant potential and provide guidance to identify aggressiveness of these tumors early in the course of management. Lastly, strong evidence to provide specific adjuvant therapy is also warranted.

Falcine and parasagittal intracranial chondrosarcomas of the classical variant: report of two cases with review of literature.

Intracranial primary extraskeletal chondrosarcomas are extremely rare. We report two cases of the classical variant which were dural based: one falcine and the other parasagittal are presented. Only 10 cases of this variant have been reported in this location. The pathology and management of these lesions have been reviewed.