Alberto Franzin

Immunobiological Characterization of Cancer Stem Cells Isolated from Glioblastoma Patients

Purpose: Cancer stem cells (CSC) have been isolated from human tumors, including glioblastoma multiforme (GBM). The aims of this study were the immunobiological characterization of GBM CSCs and the assessment of whether these cells represent suitable targets for immunotherapy. Experimental Design: GBM CSC lines and their fetal bovine serum (FBS)–cultured non-CSC pair lines were generated and examined by flow cytometry for expression of known tumor antigens, MHC-I and MHC-II molecules, antigen-processing machinery components, and NKG2D ligands. In addition, immunogenicity and immunosuppression of such cell lines for autologous or allogeneic T lymphocytes were tested by cytokine secretion (ELISPOT) or proliferation (carboxyfluorescein diacetate succinimidyl ester) assays, respectively. Results: Both GBM CSC and FBS lines were weakly positive and negative for MHC-I, MHC-II, and NKG2D ligand molecules, respectively. Antigen-processing machinery molecules were also defective in both cell types. Upregulation of most molecules was induced by IFNs or 5-Aza deoxycytidine, although more efficiently in FBS than in CSCs. Patient T-cell responses, mediated by both TH1 and the TH2 subsets, against autologous CSC could be induced in vitro. In addition, CSC but not their paired FBS tumor lines inhibited T-cell proliferation of healthy donors. Notably, a differential gene signature that was confirmed at the protein levels for some immunologic-related molecules was also found between CSC and FBS lines. Conclusions: These results indicate lower immunogenicity and higher suppressive activity of GBM CSC compared with FBS lines. The immunogenicity, however, could be rescued by immune modulation leading to anti-GBM T cell–mediated immune response. Clin Cancer Res; 16(3); 800–13

Epidermal Growth Factor Receptor Expression Identifies Functionally and Molecularly Distinct Tumor-Initiating Cells in Human Glioblastoma Multiforme and Is Required for Gliomagenesis

Epidermal growth factor receptor (EGFR) is a known diagnostic and, although controversial, prognostic marker of human glioblastoma multiforme (GBM). However, its functional role and biological significance in GBM remain elusive. Here, we show that multiple GBM cell subpopulations could be purified from the specimens of patients with GBM and from cancer stem cell (CSC) lines based on the expression of EGFR and of other putative CSC markers. All these subpopulations are molecularly and functionally distinct, are tumorigenic, and need to express EGFR to promote experimental tumorigenesis. Among them, EGFR-expressing tumor-initiating cells (TIC) display the most malignant functional and molecular phenotype. Accordingly, modulation of EGFR expression by gain-of-function and loss-of-function strategies in GBM CSC lines enhances and reduces their tumorigenic ability, respectively, suggesting that EGFR plays a fundamental role in gliomagenesis. These findings open up the possibility of new therapeutically relevant scenarios, as the presence of functionally heterogeneous EGFR(pos) and EGFR(neg) TIC subpopulations within the same tumor might affect clinical response to treatment.

The role of stereotactic radiotherapy in patients with growth hormone-secreting pituitary adenoma

CONTEXT Single-session stereotactic radiotherapy (SR) may be a potential adjuvant treatment in acromegaly. OBJECTIVE We analyzed the safety and efficacy of SR in patients who had previously received maximal surgical debulking at our center. DESIGN The study was a retrospective analysis of hormonal, radiological, and ophthalmologic data collected in a predefined protocol from 1994 through 2006. SETTING The study was performed at a university hospital. PATIENTS Eighty-three acromegalic patients, 52 women and 31 men, with a mean age of 42.6 +/- 1.2 yr, participated in the study. The median follow-up was 69 months (interquartile range 44-107 months). INTERVENTION The patients were treated with SR for residual or recurrent GH-secreting adenoma. MAIN OUTCOME MEASURE Normalization of age- and sex-adjusted IGF-I levels together with a basal GH level below 2.5 microg/liter without concomitant GH-suppressive drugs was the goal of therapy. RESULTS Fifty patients (60.2%) reached the main outcome of the study. The rate of remission was 52.6% at 5 yr [95% confidence interval (CI) 40.6-64.6%]. Another 13 patients (15.7%), who were resistant to somatostatin analogs, were in remission after SR. Multivariate analysis showed that low basal GH and IGF-I levels were associated with a favorable outcome. No serious side effects occurred after SR. The 5-yr cumulative risk of new onset hypogonadism, hypothyroidism, or hypoadrenalism was 3.6% (95% CI 0-8.6%), 3.3% (95% CI 0-7.7%), and 4.9% (95% CI 0-10.4%), respectively. CONCLUSION In a highly selected group of acromegalic patients, SR treatment had good efficacy and safety. This may lead to reconsider the role of SR in the therapeutic algorithm of acromegaly.

Desmopressin stimulation test before and after pituitary surgery in patients with Cushing's disease

OBJECTIVE The desmopressin test has been proposed as a useful tool for the differential diagnosis of Cushings disease. The aim of our study was to investigate, in a large series of patients with Cushings disease, the incidence of a positive ACTH and cortisol response to desmopressin. Moreover, we repeated the test soon after surgery to verify its usefulness in the assessment of early and late surgical results.

Radiosurgery and the prevention of regrowth of incompletely removed nonfunctioning pituitary adenomas

OBJECT The authors studied the efficacy of gamma knife radiosurgery (GKS) in the prevention of regrowth of nonfunctioning pituitary adenomas (NPA). METHODS One hundred nineteen patients were included in this study and were divided into two groups. All patients had undergone surgery in our department and recurrent or residual adenoma was demonstrated on postoperative MR imaging. Group A consisted of 68 patients who were followed without additional treatment. Group B was composed of 51 patients who received GKS within 1 year after microsurgery. There was no significant demographic difference between the two groups. In Group B the mean margin dose was 16.5 ± 0.3 Gy (range 13-21 Gy). Fifty one and one tenth percent of patients in Group A were recurrence free at 5 years and 89.8% in Group B (p < 0.001). In Group B patients, tumor volume decreased from a baseline value of 2.4 ± 0.2 cm3 to 1.6 ± 0.2 cm3 at last follow up (p < 0.001). CONCLUSIONS The results of this study suggest that GKS is effective in controlling growth of residual NPA for at least 5 years following initial maximal surgical debulking compared with no radiation therapy. Thus, GKS is recommended after microsurgery when visible tumor can be detected on imaging studies.

Non-random trisomies of chromosomes 5, 8 and 12 in the prolactinoma sub-type of pituitary adenomas: Conventional cytogenetics and interphase fish study

Specimens from 53 pituitary adenomas (PAs), including 17 NFPA, 16 PRL‐, 9 ACTH‐, 9 GH‐ and 2 TSH‐secreting tumors, underwent cytogenetic analysis by the direct and short‐term culture methods. Only 8 tumors (15%) appeared to have an abnormal karyotype. To increase the resolution of cytogenetic analysis, direct preparations from 31 PAs were investigated by interphase FISH with probes specific for chromosomes 5, 8, 12 and X, for which gain in pituitary tumors has been reported. Of these 31 PAs, 17 (54.8%) had an abnormal dosage of one or more of the 4 chromosomes tested. Separate or combined trisomies of chromosomes 5, 8 and 12 were found in 10/10 prolactinomas and in 4/9 NFPA, whereas the combined loss of chromosomes 5 and 8 was observed in 1/6 ACTH‐ and 1/6 GH‐secreting PAs. Present and earlier data on 23 PAs showed that tumors with the highest frequency of abnormal karyotypes revealed by cytogenetics and/or interphase FISH were PRL (78%), followed by NFPA (26%) and GH (18%). Recurrent structural rearrangements affecting chromosomes 1, 3 and 12 were also identified in prolactinomas, which therefore appear to be the only pituitary adenoma sub‐type with a defined trend of tumor‐specific chromosomal changes. Cytogenetic and FISH analyses of different pituitary tumor sub‐types indicate that they may harbour genetically distinct lesions. Int. J. Cancer 86:344–350, 2000.

Clinical relevance of the dose of cytarabine in the upfront treatment of primary CNS lymphomas with methotrexate-cytarabine combination

BACKGROUND The combination of high doses of methotrexate (MTX) and cytarabine (araC) is the standard chemotherapy for patients with primary CNS lymphoma (PCNSL). The addition of an alkylating agent could improve MTX-araC efficacy because it is active against quiescent G0 cells and increases antimetabolites cytotoxicity. A pilot experience with high doses of MTX, araC, and thiotepa (MAT regimen) was performed to investigate feasibility and efficacy of adding an alkylating agent. With respect to MTX-araC combination, araC dose was halved to minimize toxicity. Herein, we report tolerability, activity, and efficacy of MAT regimen and compare these results to those previously reported with MTX/ara-C combination. METHODS Twenty HIV-negative patients with PCNSL treated with MAT regimen and whole-brain irradiation and selected according to eligibility criteria of the International Extranodal Lymphoma Study Group (IELSG) #20 trial were analyzed. RESULTS Patient characteristics of MAT and MTX-araC series were similar. G4 hematologic toxicity was common after MAT chemotherapy, with dose reductions in 60% of patients, infections in 20%, G4 non-hematologic toxicity in 15%, and one (5%) toxic death. Response after chemotherapy was complete in four patients (clinical response rate, 20%; 95% confidence interval, 3%-37%) and partial in three (overall response rate, 35%; 95% confidence interval, 15%-55%). Fifteen patients experienced failure and 16 died (median follow-up, 26 months), with a 2-year overall survival of 24% ± 9%. CONCLUSIONS MAT and MTX-araC combinations showed similar tolerability, whereas araC dose reduction was associated with a remarkably lower efficacy, hiding any potential benefit of thiotepa. Four doses of araC 2 g/m(2) per course are recommended in patients with PCNSL.

Dynamic contrast-enhanced and dynamic susceptibility contrast perfusion MR imaging for glioma grading: Preliminary comparison of vessel compartment and permeability parameters using hotspot and histogram analysis

INTRODUCTION Dynamic susceptibility contrast (DSC)-MRI is a perfusion technique with high diagnostic accuracy for glioma grading, despite limitations due to inherent susceptibility effects. Dynamic contrast-enhanced (DCE)-MRI has been proposed as an alternative technique able to overcome the DSC-MRI shortcomings. This pilot study aimed at comparing the diagnostic accuracy of DSC and DCE-MRI for glioma grading by evaluating two estimates of blood volume, the DCE-derived plasma volume (Vp) and the DSC-derived relative cerebral blood volume (rCBV), and a measure of vessel permeability, the DCE-derived volume transfer constant K(trans). METHODS Twenty-six newly diagnosed glioma patients underwent 3T-MR DCE and DSC imaging. Parametric maps of CBV, Vp and K(trans) were calculated and the region of highest value (hotspot) was measured on each map. Histograms of rCBV, Vp and K(trans) values were calculated for the tumor volume. Statistical differences according to WHO grade were assessed. The diagnostic accuracy for tumor grading of the two techniques was determined by ROC analysis. RESULTS rCBV, Vp and K(trans) measures differed significantly between high and low-grade gliomas. Hotspot analysis showed the highest correlation with grading. K(trans) hotspots co-localized with Vp hotspots only in 56% of enhancing gliomas. For differentiating high from low-grade gliomas the AUC was 0.987 for rCBVmax, and 1.000 for Vpmax and K(trans)max. Combination of DCE-derived Vp and K(trans) parameters improved the diagnostic performance of the histogram method. CONCLUSION This initial experience of DCE-derived Vp evaluation shows that this parameter is as accurate as the well-established DSC-derived rCBV for glioma grading. DCE-derived K(trans) is equally useful for grading, providing different informations with respect to Vp.

The role of CXCR4 in highly malignant human gliomas biology: current knowledge and future directions.

Given the extensive histomorphological heterogeneity of high‐grade gliomas, in terms of extent of invasiveness, angiogenesis, and necrosis and the poor prognosis for patients despite the advancements made in therapeutic management. The identification of genes associated with these phenotypes will permit a better definition of glioma heterogeneity, which may ultimately lead to better treatment strategies. CXCR4, a cell surface chemokine receptor, is implicated in the growth, invasion, angiogenesis and metastasis in a wide range of malignant tumors, including gliomas. It is overexpressed in glioma cells according to tumor grade and in glioma tumor initiating cells. There have been various reports suggesting that CXCR4 is required for tumor proliferation, invasion, angiogenesis, and modulation of the immune response. It may also serve as a prognostic factor in characterizing subsets of glioblastoma multiforme, as patients with CXCR4‐positive gliomas seem to have poorer prognosis after surgery. Aim of this review was to analyze the current literature on biological effects of CXCR4 activity and its role in glioma pathogenesis. A better understanding of CXCR4 pathway in glioma will lead to further investigation of CXCR4 as a novel putative therapeutic target. GLIA 2014;62:1015–1023

Results of Gamma Knife Radiosurgery in Acromegaly

Objective. Single-session radiosurgery with Gamma Knife (GK) may be a potential adjuvant treatment in acromegaly. We analyzed the safety and efficacy of GK in patients who had previously received maximal surgical debulking at our hospital. Methods. The study was a retrospective analysis of hormonal, radiological, and ophthalmologic data collected in a predefined protocol from 1994 to 2009. The mean age at treatment was 42.3 years (range 22–67 yy). 103 acromegalic patients participated in the study. The median follow-up was 71 months (IQ range 43–107). All patients were treated with GK for residual or recurrent GH-secreting adenoma. Results. Sixty-three patients (61.2%) reached the main outcome of the study. The rate of remission was 58.3% at 5 years (95% CI 47.6–69.0%). Other 15 patients (14.6%) were in remission after GK while on treatment with somatostatin analogues. No serious side effects occurred after GK. Eight patients (7.8%) experienced a new deficit of pituitary function. New cases of hypogonadism, hypothyroidism, and hypoadrenalism occurred in 4 of 77 patients (5.2%), 3 of 95 patients (3.2%), and 6 of 100 patients at risk (6.0%), respectively. Conclusion. In a highly selected group of acromegalic patients, GK treatment had good efficacy and safety.