Maurizio Martini

Cancer Stem Cell Analysis and Clinical Outcome in Patients with Glioblastoma Multiforme

Purpose: Cancer stem cells (CSC) are thought to represent the population of tumorigenic cells responsible for tumor development. The stem cell antigen CD133 identifies such a tumorigenic population in a subset of glioblastoma patients. We conducted a prospective study to explore the prognostic potential of CSC analysis in glioblastoma patients. Experimental Design: We investigated the relationship between the in vitro growth potential of glioblastoma CSCs and patient death or disease progression in tumors of 44 consecutive glioblastoma patients treated with complete or partial tumorectomy followed by radiotherapy combined with temozolomide treatment. Moreover, we evaluated by immunohistochemistry and immunofluorescence the prognostic value of the relative presence of CD133+ and CD133+/Ki67+ cells in patient tumors. Results:In vitro CSC generation and the presence of ≥2% CD133+ cells in tumor lesions negatively correlated with overall (P = 0.0001 and 0.02, respectively) and progression-free (P = 0.0002 and 0.01, respectively) survival of patients. A very poor overall (P = 0.007) and progression-free (P = 0.001) survival was observed among patients whose tumors contained CD133+ cells expressing Ki67. Taking into account symptom duration, surgery type, age, O6-methylguanine-DNA methyltransferase promoter methylation, and p53 status, generation of CSCs and CD133/Ki67 coexpression emerged as highly significant independent prognostic factors, with an adjusted hazard ratio of 2.92 (95% confidence interval, 1.37-6.2; P = 0.005) and 4.48 (95% confidence interval, 1.68-11.9; P = 0.003), respectively. Conclusions: The analysis of CSCs may predict the survival of glioblastoma patients. In vitro CSC generation and presence of CD133+/Ki67+ cells are two considerable prognostic factors of disease progression and poor clinical outcome.

Stereotyped B-cell receptor is an independent risk factor of chronic lymphocytic leukemia transformation to Richter syndrome.

Purpose: Few biological prognosticators are useful for prediction of Richter syndrome (RS), representing the transformation of chronic lymphocytic leukemia (CLL) to aggressive lymphoma. Stereotyped B-cell receptors (BCR) may have prognostic effect in CLL progression. We tested the prognostic effect of stereotyped BCR for predicting RS transformation. Experimental Design: The prevalence of stereotyped BCR was compared in RS (n = 69) versus nontransformed CLL (n = 714) by a case-control analysis. Subsequently, the effect of stereotyped BCR at CLL diagnosis on risk of RS transformation was actuarially assessed in a consecutive CLL series (n = 753). Results: RS (n = 69) displayed a higher prevalence of stereotyped BCR (P < 0.001) compared with nontransformed CLL. The actuarial risk of RS transformation was significantly higher in CLL carrying stereotyped BCR (P < 0.001). Among BCR subsets most represented in CLL, subset 8 using IGHV4-39/IGHD6-13/IGHJ5 carried the highest risk of RS transformation [hazard ratio (HR), 24.50; P < 0.001]. Multivariate analysis selected stereotyped BCR (HR, 3.33; P = 0.001) and IGHV4-39 usage (HR, 4.03; P = 0.004) as independent predictors of RS transformation. The combination of IGHV4-39 usage and stereotyped BCR in the same patient identified CLL with a very high risk of RS transformation (5-year risk, 68.7%). The risk carried by stereotyped BCR and IGHV4-39 usage was specific for RS transformation and had no effect on CLL progression without transformation. Conclusions: Analysis of BCR features may help identify CLL patients at risk of RS. A close monitoring and a careful biopsy policy may help early recognition of RS in CLL patients using stereotyped BCR, particularly if combined with IGHV4-39.

Possible involvement of hMLH1, p16(INK4a) and PTEN in the malignant transformation of endometriosis.

Endometriosis is a common gynecologic disease, which generally follows a benign course. Notwithstanding, several clinical and histologic studies as well as molecular data show that endometriosis could be a precursor of sporadic endometrioid and clear cell carcinomas at extrauterine loci. Several reports have implicated alterations of the hMLH1 and p16ink4a (p16) genes, in particular hypermethylation of the promoter region, and of the PTEN gene, principally genetic mutations, in endometrial and ovarian cancers and have indicated that these alterations are already present in precancer conditions. In this report, we analyzed the methylation status of hMLH1 and p16 and the protein expression of PTEN and hMLH1 in 46 cases of endometriosis stages III and IV to better define the possible involvement of these genes in the malignant transformation of endometriosis. We found abnormal methylation of hMLH1 in 4 of the 46 cases (8.6%). In addition, these cases had no detectable hMLH1 protein expression. Regarding patients with hMLH1 alterations, 2 were classified as stage IV and 2 showed coexistent endometriosis and carcinoma. Only 1 case of endometriosis (2.17%), classified as atypical, showed abnormal methylation of p16. Reduced PTEN protein expression was detected in 7 of 46 cases (15.21%): 5 were clinically classified as stage IV, and the other 2 presented both cancer and hypermethylated hMLH1. Our preliminary study suggests that reduced expression of both hMLH1 and PTEN may be involved in the malignant evolution of endometriosis and should be used as markers of neoplastic transformation in aggressive endometriosis with elevated tumor markers.

Markers of myeloproliferative diseases in childhood polycythemia vera and essential thrombocythemia

PURPOSE Polycythemia vera (PV) and essential thrombocythemia (ET) can present in pediatric age as sporadic or familial diseases. To define the biologic profile of childhood PV and ET, we evaluated specific markers in a cohort of pediatric patients affected by PV and ET, including cases with familial occurrence. PATIENTS AND METHODS Thirty-eight children with PV and ET were investigated. The control group included 58 adults with PV and ET. Endogenous erythroid colonies, qualitative reverse transcriptase polymerase chain reaction for polycythemia rubra vera-1 (PRV-1) RNA expression, human androgen receptor assay and allele specific polymerase chain reaction for JAK2 V617F mutation were undertaken in all patients. Thrombopoietin, thrombopoietin receptor (c-mpl), and erythropoietin receptor mutation analysis was performed by direct sequencing in familial cases. RESULTS The JAK2 V617F mutation in children with PV was significantly less frequent than in adult PV. The most common myeloproliferative marker found in these patients was PRV-1 RNA overexpression. Children and adults with sporadic ET showed a similar proportion of patients with PRV-1 RNA overexpression, JAK2 V617F mutation, and clonality, while none of the familial ET showed JAK2 V617F mutation and clonality. Also, PRV-1 RNA overexpression was significantly less common. Furthermore, most patients with familial ET exhibited the dominant-positive activating mutation of c-mpl. Finally, children with PV and ET had a significant lower incidence of thrombosis than adults. CONCLUSION This study demonstrates that familial and sporadic ET recognize different pathogenetic mechanisms. Myeloproliferative markers are specific tests for the diagnosis of ET in children with sporadic forms, while a significant proportion of children with PV can prove negative.

Epstein-Barr Virus Infection Is Predictive of CNS Involvement in Systemic AIDS-Related Non-Hodgkin’s Lymphomas

PURPOSE This study aimed at correlating Epstein-Barr virus (EBV) infection of systemic AIDS-related non-Hodgkin lymphomas (AIDS-NHL) with the development of a CNS localization of the tumor. PATIENTS AND METHODS Demographic, epidemiologic, clinical, histologic, and virologic features were collected for all systemic AIDS-NHL patients included in the study (n = 50). Pathologic specimens were classified according to the working formulation for NHL and the Revised European-American Lymphoma classification. EBV infection in tumor tissue samples was studied by EBV small encoded RNA in situ hybridization; EBV-DNA detection in CSF was carried out by nested polymerase chain reaction using Epstein-Barr nuclear antigen-1-specific primers. In addition, selected EBV-positive lymphomas were subjected to a detailed characterization of EBV molecular heterogeneity. RESULTS Eleven patients had a CNS involvement at some point during their clinical history (four at diagnosis and seven at relapse). Thirty patients (11 with CNS involvement and 19 without) harbored EBV infection of the tumor. Sensitivity, specificity, and positive and negative predictive values of EBV-DNA detection in CSF for CNS involvement by lymphoma were 90%, 100%, 100%, and 97.6%, respectively. Factors significantly predictive of CNS involvement were EBV infection of the tumor (P=.003), an extranodal disease at diagnosis other than CNS (P=.006), and a non-CNS relapse (P=.01). In four cases of CNS involvement, EBV-DNA in CSF preceded any other sign of disease by a mean of 35 days. CONCLUSION These results show that EBV infection of the tumor clone significantly increases the risk of CNS involvement by systemic AIDS-NHL, without regard of specific molecular features. The detection of EBV-DNA in the CSF of AIDS-NHL patients may select cases with higher risk of CNS involvement and, therefore, may prove useful in the therapeutic stratification of these tumors.

Expression of the stem cell marker CD133 in recurrent glioblastoma and its value for prognosis.

Experimental data suggest that glioblastoma cells expressing the stem cell marker CD133 play a major role in radiochemoresistance and tumor aggressiveness. To date, however, there is no clinical evidence that the fraction of CD133‐positive cells in glioblastoma that recurs after radiochemotherapy may be relevant for prognosis.

BRAF (V600E) mutation analysis on liquid-based cytology-processed aspiration biopsies predicts bilaterality and lymph node involvement in papillary thyroid microcarcinoma

Activating mutations in the valine‐to‐glutamic acid substitution at position 600 of the v‐raf murine sarcoma viral oncogene homolog B1 (BRAF‐1) gene are detected frequently in patients with papillary thyroid carcinoma (PTC). These mutations have been identified in approximately 29% to 69% of PTCs and in >80% of PTCs of the tall cell variant, whereas they have not been detected in benign lesions or in the majority of those (80%) with the follicular variant of PTC. The objective of the current study was to evaluate the role of liquid‐based cytology (LBC) for the detection of BRAF mutations in the outcome of patients who have thyroid PTC measuring ≤1 cm and, hence, in guiding their clinical and surgical management.

Is there a role for IGF1R and c-MET pathways in resistance to cetuximab in metastatic colorectal cancer?

BACKGROUND The KRAS mutation is not responsible for all cases of resistance to anti-epidermal growth factor receptors (EGFRs) in metastatic colorectal cancer (mCRC), and new predictive and prognostic factors are actively being sought. PATIENTS AND METHODS We retrospectively evaluated the efficacy of a cetuximab-containing treatment in 73 patients with mCRC according to KRAS and BRAF mutational status as well as PTEN, c-MET, and insulin-like growth factor receptor (IGF1R) expression. RESULTS Overall response rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) were significantly lower in patients with KRAS mutation than in patients with KRAS wild-type; among the population with KRAS wild-type, only 2 patients with BRAF mutations were found and neither of them achieved a response. No significant association was found between PTEN and clinical outcome. Compared with low/normal expression, c-MET overexpression significantly correlated with shorter mPFS and mOS: 3 vs. 5 months (P = .018) and 11 vs. 10 months (P = .037), respectively. In patients with high IGF1R expression, mOS was significantly longer than in those with low/normal expression (14 vs. 8 months; P = .015). CONCLUSION KRAS mutation significantly correlates with a worse outcome in patients treated with cetuximab, whereas no definitive inference can be drawn about the role of BRAF mutation and PTEN loss of expression. Instead, c-MET overexpression might represent a negative prognostic factor in mCRC and may have a role in resistance to anti-EGFR therapy. Interestingly, IGF1R overexpression seems a favorable prognostic factor in mCRC.

Overexpression of the Polycythemia Rubra Vera-1 Gene in Essential Thrombocythemia

PURPOSE To examine the utility of polycythemia rubra vera-1 (PRV-1)-specific reverse transcriptase polymerase chain reaction (RT-PCR) to discriminate essential thrombocythemia (ET) and polycythemia vera (PV) from secondary thrombocytosis (ST) or secondary erythrocytosis (SE). PATIENTS AND METHODS We analyzed the expression of PRV-1 in granulocytes isolated from 37 patients with ET, 37 patients with PV, 25 patients with ST, 10 patients with SE, 25 patients with secondary leukocytosis (SL), five patients with chronic myelogenous leukemia (CML), five patients with chronic idiopathic myelofibrosis (IM), five patients with myelodysplastic syndrome (MDS), and 20 normal individuals by PRV-1-specific RT-PCR. In female patients, PRV-1 expression was correlated with clonality analysis as assessed by the human androgen receptor polymorphism assay. RESULTS PRV-1 was not expressed in granulocytes isolated from normal individuals or from patients with ST, SE, CML, IM, MDS, and inflammatory/infectious SL. On the contrary, all ET patients, 35 of 37 PV patients, and five patients with acute postsurgery and posttraumatic SL overexpressed PRV-1. All the cases with monoclonal hematopoiesis (17 of 21 with ET and 12 of 12 with PV) expressed PRV-1, yet PRV-1 overexpression extended also over the cases of ET showing polyclonal hematopoiesis (four of 20). CONCLUSION The overexpression of PRV-1 seems to be a useful tool for discriminating ET and PV from ST and SE, thus offering an innovative diagnostic approach on the basis of the detection of positive diagnostic criteria instead of exclusion criteria.

Epigenetic silencing of SOCS3 identifies a subset of prostate cancer with an aggressive behavior

Chronic inflammation and subsequent tissutal alterations may play a key role in prostate carcinogenesis. In this way, molecular alterations of the suppressor of cytokine signaling 3 (SOCS3), one of the most important inhibitory molecule of inflammatory signal transduction circuitries, could contribute to explain the pleiotropic role of interleukin‐6 (IL‐6) in this type of cancer.