Alessandro Frati

Pro-inflammatory gene expression in solid glioblastoma microenvironment and in hypoxic stem cells from human glioblastoma

BackgroundAdaptation to hypoxia and consequent pro-inflammatory gene expression of prostate and breast carcinomas have been implicated in the progression toward cancer malignant phenotype. Only partial data are available for the human tumor glioblastoma multiforme (GBM). The aim of our study was to analyze the hypoxic and pro-inflammatory microenvironment in GBMs and to demonstrate that in a stem/progenitor cell line derived from human glioblastoma (GBM-SCs), hypoxia activates a coordinated inflammatory response, evidencing an invasive and migratory phenotype.MethodsFrom each of 10 human solid glioblastomas, clinically and histopathologically characterized, we obtained three surgical samples taken from the center and the periphery of the tumor, and from adjacent host normal tissue. Molecular and morphological analyses were carried out using quantitative real-time PCR and western blot (WB). GBM stem and differentiated cells were incubated under hypoxic conditions and analyzed for pro-inflammatory gene expression and for invasive/migratory behavior.ResultsA panel of selected representative pro-inflammatory genes (RAGE and P2X7R, COX2, NOS2 and, PTX3) were analyzed, comparing tumor, peritumor and host normal tissues. Tumors containing leukocyte infiltrates (as assessed using CD45 immunohistochemistry) were excluded. Selected genes were overexpressed in the central regions of the tumors (i.e. in the more hypoxic areas), less expressed in peripheral regions, and poorly expressed or absent in adjacent normal host tissues. Western blot analysis confirmed that the corresponding pro-inflammatory proteins were also differently expressed. Hypoxic stem cell lines showed a clear time-dependent activation of the entire panel of pro-inflammatory genes as compared to differentiated tumor cells. Biological assays showed that invasive and migratory behavior was strengthened by hypoxia only in GBM stem cells.ConclusionsIn human solid glioblastoma we have observed a coordinated overexpression of a panel of pro-inflammatory genes as compared to host normal tissue. We have also evidenced a similar pattern of overexpressed genes in GBM-SCs after hypoxic treatment, showing also a gain of invasive and migratory function that was lost when these stem cells differentiated. We suggest that, as has been previously described for prostatic and mammary carcinoma, in human glioblastoma acquisition of a proinflammatory phenotype may be relevant for malignant progression.

Multicentric glioma: our experience in 25 patients and critical review of the literature

Multicentric gliomas are interesting and well-recognised entities with a yet unknown rate of occurrence. Single cases or small series are reported in the literature accessible to us, and we think this is the first large series describing true multicentric gliomas. We reviewed 25 patients selected according to the criteria defined by Batzdorf and Malamud. Multicentricity was found in 2% of patients with malignant gliomas. Longer survival was observed in patients who underwent surgical excision of the multicentric lesions. Multicentric tumours are rare clinical entities. Our data suggest that they should be surgically removed whenever possible, and histopathologic examination of the lesions is always advisable if they are located in sites inaccessible to surgery. Stereotactic biopsy represents a safe and satisfactory method for achieving sure diagnosis.

Single brain metastasis from thyroid cancer: Report of twelve cases and review of the literature

Brain metastases from thyroid carcinoma is unusual, with a frequency of 1%.We report twelve patients, with single brain metastases and with a karnofsky performance scale score ≥60 at admission. No metastasis was seen during the uptake of iodine-131, even in the cases from differentiated thyroid carcinoma, suggesting absence of differentiation between primary and metastasic disease. The histopathology of thyroid carcinomas was anaplastic in five cases, differentiated in six, and medullary in one. Only in four patients, brain was the unique site of metastatic spread; in others, bones and lungs were also involved. All metastases were surgically removed, and all patients were treated with radiotherapy (45 Gy) in the postoperative course. The survival average was 19.8 months, and the quality of life was satisfactory in all patients. One patient remained alive till 5 years. Anaplastic histopathology and size of the primitive, and also bone involvement of thyroid disease were significant risk factors in our cases (p ≤ 0.05). According to the literature, surgery is the best therapeutical choice. Alternative strategies in the management of brain metastasis, such as iodine-131 therapy, are discussed, paying particular attention to the relevant side effects.

Frameless Stereotactic Cerebral Biopsy: Our Experience in 296 Cases

Aims: To evaluate the reliability, safety and accuracy of a the frameless stereotactic system in our clinical series and the differences between head fixation by means of a standard Mayfield head holder and the pinless FESS frame, and to evaluate the usefulness of biopsy targeting on the basis of magnetic resonance spectroscopy (MRS) data. Methods: The spectroscopic analysis was used to facilitate the targeting of the lesion. The fusion image function embedded in the Neuronavigation Unit was used postoperatively to assess the level of accuracy of the biopsy. The grading of the glioma specimens was correlated to the spectroscopic data. Results: 296 patients underwent cerebral biopsy in 8 years. The diagnostic yield was 99.7%. The spectroscopic choline/N-acetyl aspartate ratio in different areas of the same tumor correlated well with the histological grading of the lesion. Conclusion: The frameless stereotactic systems guarantee excellent biopsy results. Advanced imaging, in particular MRS, facilitates the correct targeting of nonenhancing lesions.

Rapamycin inhibits the growth of glioblastoma

The molecular target of rapamycin (mTOR) is up-regulated in glioblastoma (GBM) and this is associated with the rate of cell growth, stem cell proliferation and disease relapse. Rapamycin is a powerful mTOR inhibitor and strong autophagy inducer. Previous studies analyzed the effects of rapamycin in GBM cell lines. However, to our knowledge, no experiment was carried out to evaluate the effects of rapamycin neither in primary cells derived from GBM patients nor in vivo in brain GBM xenograft. These data are critical to get a deeper insight into the effects of such adjuvant therapy in GBM patients. In the present study, various doses of rapamycin were tested in primary cell cultures from GBM patients. These effects were compared with that obtained by the same doses of rapamycin in GBM cell lines (U87Mg). The effects of rapamycin were also evaluated in vivo, in brain tumors developed from mouse xenografts. Rapamycin, starting at the dose of 10nm inhibited cell growth both in U87Mg cell line and primary cell cultures derived from various GBM patients. When administered in vivo to brain xenografts in nude mice rapamycin almost doubled the survival time of mice and inhibited by more than 95% of tumor volume.

Diffuse axonal injury and oxidative stress: A comprehensive review

Traumatic brain injury (TBI) is one of the world’s leading causes of morbidity and mortality among young individuals. TBI applies powerful rotational and translational forces to the brain parenchyma, which results in a traumatic diffuse axonal injury (DAI) responsible for brain swelling and neuronal death. Following TBI, axonal degeneration has been identified as a progressive process that starts with disrupted axonal transport causing axonal swelling, followed by secondary axonal disconnection and Wallerian degeneration. These modifications in the axonal cytoskeleton interrupt the axoplasmic transport mechanisms, causing the gradual gathering of transport products so as to generate axonal swellings and modifications in neuronal homeostasis. Oxidative stress with consequent impairment of endogenous antioxidant defense mechanisms plays a significant role in the secondary events leading to neuronal death. Studies support the role of an altered axonal calcium homeostasis as a mechanism in the secondary damage of axon, and suggest that calcium channel blocker can alleviate the secondary damage, as well as other mechanisms implied in the secondary injury, and could be targeted as a candidate for therapeutic approaches. Reactive oxygen species (ROS)-mediated axonal degeneration is mainly caused by extracellular Ca2+. Increases in the defense mechanisms through the use of exogenous antioxidants may be neuroprotective, particularly if they are given within the neuroprotective time window. A promising potential therapeutic target for DAI is to directly address mitochondria-related injury or to modulate energetic axonal energy failure.

Short-term radiotherapy followed by adjuvant chemotherapy in poor-prognosis patients with glioblastoma

OBJECTIVES The optimal treatment for patients with glioblastoma with unfavorable prognostic factors, such as old age and low performance status, remains controversial. We conducted a prospective study to assess the effect of temozolomide and short-course radiation versus short-course radiation alone in the treatment of poor-prognosis patients with newly diagnosed glioblastoma. PATIENTS AND METHODS Forty-five patients with a newly diagnosed glioblastoma, older than 70 years or aged 50-70 years and with a Karnofsky performance score <or=70 were enrolled in this prospective study. Twenty-three patients were treated with an abbreviated course of radiotherapy (30 Gy in 6 fractions over 2 weeks) and 22 patients with the same radiotherapy schedule plus adjuvant temozolomide at the dose of 150-200 mg/m(2) for 5 days every 28-day cycle. The primary end point was overall survival. Secondary end points included progression-free survival and toxicity. RESULTS Median overall survival was 7.3 months in the radiotherapy group and 9.4 months in the radiotherapy plus temozolomide group (P = 0.003), with respective 6-month overall survivals of 78% and 95%, respectively. Median progression-free survival was 4.4 months in the radiotherapy group and 5.5 months in the radiotherapy plus temozolomide group (P = 0.01), and respective 6-month progression-free survival rates were 22% and 45%. In multivariate analysis, Karnofsky performance score was the only significant independent predictive factor of survival (P = 0.03). Adverse effects of radiotherapy were mainly represented by neurotoxicity (24%), which resolved in most cases with the use of steroids. Grade 3-4 hematologic toxicity occurred in 36% of patients treated with temozolomide. CONCLUSIONS The addition of temozolomide to short-term radiotherapy resulted in a statistically significant survival benefit with minimal additional toxicity in poor-prognosis patients with newly diagnosed glioblastoma. Future studies need to define the best combined regimens of radiotherapy and temozolomide on survival and quality of life in this subgroup of patients.

Post-traumatic glioma. Report of four cases and review of the literature

Aims and background To add a further contribution to the literature supporting the relationship between previous head trauma and development of glioma. Methods We report on four patients who developed brain gliomas in the scar of an old brain injury. Results All cases fulfilled the widely established criteria for brain tumors of traumatic origin. In all of our cases there was radiological evidence of absence of tumor at the time of the injury. Conclusions We believe that in specific cases it is reasonable to acknowledge an etiological association between a severe head trauma and the development of a glioma. This assumption is further sustained if there is radiological and surgical documentation of the absence of neoplasia at the moment of the trauma.

The role of autophagy in epileptogenesis and in epilepsy-induced neuronal alterations.

Recent evidence suggests that autophagy alterations are present in a variety of neurological disorders. These range from neurodegenerative diseases to acute neurological insults. Thus, despite a role of autophagy was investigated in a variety of neurological diseases, only recently these studies included epilepsy. This was fostered by the evidence that rapamycin, a powerful autophagy inducer, strongly modulates a variety of seizure models and epilepsies. These findings were originally interpreted as the results of the inhibition exerted by rapamycin on the molecular complex named “mammalian Target of Rapamycin” (mTOR). Recently, an increasing number of papers demonstrated that mTOR inhibition produces a strong activation of the autophagy machinery. In this way, it is now increasingly recognized that what was once defined as mTORpathy in epileptogenesis may be partially explained by abnormalities in the autophagy machinery. The present review features a brief introductory statement about the autophagy machinery and discusses the involvement of autophagy in seizures and epilepsies. An emphasis is posed on evidence addressing both pros and cons making it sometime puzzling and sometime evident, the role of autophagy in the epileptic brain.

Extremely delayed cerebral metastasis from renal carcinoma: report of four cases and critical analysis of the literature.

Brain metastases from renal carcinoma may appear even a long time after surgical treatment of the primary tumor. The authors present 2 series of patients, one of which has already been published and the other new, for a total of 4 cases of brain metastasis from renal carcinoma with late onset, which occurred 13, 17, 26 and 12 years after primary surgical treatment. The other cases described in the literature were also critically reviewed.