BackgroundPancreatic ductal adenocarcinoma (PDAC) remains a leading cause of cancer mortality for which novel gene therapy approaches relying on tumor-tropic adenoviruses are being tested.MethodsWe obtained the global transcriptional profiling of primary PDAC using RNA from eight xenografted primary PDAC, three primary PDAC bulk tissues, three chronic pancreatitis and three normal pancreatic tissues. The Affymetrix GeneChip HG-U133A was used. The results of the expression profiles were validated applying immunohistochemical and western blot analysis on a set of 34 primary PDAC and 10 established PDAC cell lines. Permissivity to viral vectors used for gene therapy, Adenovirus 5 and Adeno-Associated Viruses 5 and 6, was assessed on PDAC cell lines.ResultsThe analysis of the expression profiles allowed the identification of two clearly distinguishable phenotypes according to the expression of interferon-stimulated genes. The two phenotypes could be readily recognized by immunohistochemical detection of the Myxovirus-resistance A protein, whose expression reflects the activation of interferon dependent pathways. The two molecular phenotypes discovered in primary carcinomas were also observed among established pancreatic adenocarcinoma cell lines, suggesting that these phenotypes are an intrinsic characteristic of cancer cells independent of their interaction with the host's microenvironment. The two pancreatic cancer phenotypes are characterized by different permissivity to viral vectors used for gene therapy, as cell lines expressing interferon stimulated genes resisted to Adenovirus 5 mediated lysis in vitro. Similar results were observed when cells were transduced with Adeno-Associated Viruses 5 and 6.ConclusionOur study identified two molecular phenotypes of pancreatic cancer, characterized by a differential expression of interferon-stimulated genes and easily recognized by the expression of the Myxovirus-resistance A protein. We suggest that the detection of these two phenotypes might help the selection of patients enrolled in virally-mediated gene therapy trials.

Multiple myeloma is a malignancy of B-cells that is characterized by the clonal expansion and accumulation of malignant plasma cells in the bone marrow. This disease remains incurable, and a median survival of 3-5 years has been reported with the use of current treatments. Viral-based therapies offer promising alternatives or possible integration with current therapeutic regimens. Among several gene therapy vectors and oncolytic agents, adenovirus has emerged as a promising agent, and it is already being used for the treatment of solid tumors in humans. The main concern with the clinical use of this vector has been its high immunogenicity; adenovirus is often able to induce a strong immune response in the host. Furthermore, new limitations in the efficacy of this therapy, intrinsic to the nature of tumor cells, have been recently observed. For example, our group showed a strong antiviral phenotype in vitro and in vivo in a subset of tumors, shedding new insights that may explain the partial failure of clinical trials based on this promising new therapy. In this review, we describe novel therapeutic approaches that implement viral-based treatments in hematological malignancies and address the novelty as well as the possible limitations of these new therapies, especially in the context of the use of adenoviral vectors for treating multiple myeloma.

Background: CMV infection represents a major complication of allo-SCT affecting transplant related mortality and morbidity. Anti-viral therapy is toxic and prolonged treatment could affect graft function. Monitoring specific immune response against CMV could optimize the timing for anti-viral therapy administration in order to avoid related toxicity and to reduce CMV related mortality and morbidity. A recent ELISA based test (QuantiFERON®-CMV) could measure specific (anti-HCMV) and aspecific production of IFN-γ in whole blood. Aims: to test the reliability of QuantiFERON®-CMV in a cross sectional study in order to identify patients at risk of CMV disease after alloHSCT. Methods: QuantiFERON®-CMV is an in vitro diagnostic test using a peptide cocktail simulating human cytomegalovirus proteins (CMV) to stimulate cells in heparinised whole blood. Detection of interferon-γ (IFN-γ) by ELISA is used to identify in vitro responses to these peptide antigens that are associated with CMV infection. The IFN-γ response in the CMV Ag tube is considered positive if > 0.2 UI/mL as defined by the manufacturer. The mitogen-stimulated plasma sample was used as an IFN-γ positive control (PC) for each specimen tested. CMV reactivation and disease were defined according EBMT recommendations. Results: Among 92 tests no correlation between pp65 antigenemia and IFN-γ production was proved (p=0,346). However, among the 41 tests showing lower levels of anti-HCMV IFN-γ production (<0.2 IU/mL) 8 tests belonging 4 patients were associated with CMV disease, whereas among the 51 tests showing higher levels of anti-HCMV IFN-γ production (>=0.2 IU/mL) none were associated with CMV disease (p=0.001), RR 2.5 (CI95% 1.951–3.321). Conclusions: QuantiFERON®-CMV doesn’t seem to represent a significant reliable test for risk of viremia after alloHSCT, but patients with prolonged lower levels of anti-HCMV IFN-γ production (<0.2 IU/mL) are at risk of CMV disease. Prospective studies are required in order to identify the correlation between viremia and the need for treatment.

Background. GVHD is associated with a high morbidity and mortality in alloSCT patients. An early diagnosis of GVHD could reduce this adverse impact on the outcome of alloSCT. The effect of Th1 cytokine IFN-γ is crucial in the pathogenesis of GVHD and, as expected, higher protein levels are reported in the serum of patients with active chronic GVHD. The monitoring of IFN-γ basal levels as well as IFN-γ induced by mitogen stimulation in the blood samples of patients after alloSCT could help the management and the prediction of GVHD. A recent ELISA based test (QuantiFERON®-CMV) could measure specific (anti-CMV) and aspecific production of IFN-γ in whole blood. The aim of this study is to assess the reliability of the positive control of the QuantiFERON®-CMV kit as new marker for GVHD early diagnosis. Methods. The study was performed in 2 phases. In the first phase of the study, 92 whole blood specimens were collected and analyzed from 29 patients undergoing alloSCT. In the second phase 10 patients were observed prospectively with collection of blood samples every 2–3 weeks since engraftment until 4–6 months after SCT in order to study the PHA stimulated IFN-γ production in relationship with the onset of chronic GVHD. QuantiFERON®-CMV is an in vitro diagnostic test that use an antigenic human cytomegalovirus proteins (CMV) peptide cocktail to stimulate cells from whole blood. The mitogen-stimulated (PHA) plasma sample is used as an IFN-γ positive control for each specimen tested. Detection of interferon-γ (IFN-γ) by ELISA is used to identify responses. In order to assess the association between IFN-γ response due to PHA stimulation and GVHD, the positivity of the test was determined according to 2 different cut-off: #1) 0,5 IU/mL as defined by manufacturer, #2) 9 IU/mL as experimentally defined by the median of the observations in our data set. GVHD extension was defined by Seattle criteria and/or the number of involved sites, Chi-square test was used to assess the statistical correlation between IFN-γ production and clinical outcomes. Results. In the first phase, among 92 samples 70 were positive for the PHA stimulated IFN-γ production according to the cut-off #1; 61% (43/70) were associated with GVHD whereas 27% (6/22) with lower PHA stimulated IFN-γ production were associated with GVHD: this difference was proved to be significant (p=0.005). According to the cut-off #2 46 samples out of 92 were positive for the PHA stimulated IFN-γ production; 71% (33/46) were associated with GVHD whereas 34% (16/46) with lower PHA stimulated IFN-γ production were associated with GVHD: this difference was proved to be significant (p=0.000). In the second prospective phase of the study, 7/10 patients became positive for the PHA stimulated IFN-γ production after alloSCT: 6 developed subsequently chronic GVHD. The median time to the onset of GVHD was 100 days from the first sample proved positive above the cut-off #1 and 33 days from the first sample proved positive above the cutoff#2. Four patients received steroid treatment for extensive chronic GVHD and their PHA stimulated IFN-γ production dropped after treatment (figure 1, continuous line). Conclusions: The PHA stimulated IFN-γ production is associated with GVHD. The monitoring of PHA stimulated IFN-γ after alloSCT seems to predict the onset of GVHD and could help in the modulation of immunosuppressive treatment. However, larger prospective studies are needed. Figure Figure