Giuseppa Penna

The cancer stem cell hypothesis: a guide to potential molecular targets.

Common cancer theories hold that tumor is an uncontrolled somatic cell proliferation caused by the progressive addition of random mutations in critical genes that control cell growth. Nevertheless, various contradictions related to the mutation theory have been reported previously. These events may be elucidated by the persistence of residual tumor cells, called Cancer Stem Cells (CSCs) responsible for tumorigenesis, tumor maintenance, tumor spread, and tumor relapse. Herein, we summarize the current understanding of CSCs, with a focus on the possibility to identify specific markers of CSCs, and discuss the clinical application of targeting CSCs for cancer treatment.

Bisphosphonates Induce Apoptosis of Circulating Endothelial Cells in Multiple Myeloma Patients and in Subjects with Bisphosphonate-Induced Osteonecrosis of the Jaws

Bisphosphonates (BPs) are the current standard of care for bone lesions in patients with multiple myeloma (MM) but they are associated with a number of side effects such as osteonecrosis of the jaw. The exact mechanisms of osteonecrosis are not elucidated, and its physiopathology is based on several hypotheses such as a decrease in bone remodeling or an inhibitory effect on angiogenesis. The aim of our study was to investigate the mechanism involved in the pathogenesis of osteonecrosis. We examined the apoptosis of circulating endothelial progenitor cells in MM subjects before and after BP treatment and in osteonecrosis patients using a flow-cytometric analysis. Our data showed an increase in endothelial cell apoptosis in MM patients after BP administration and in osteonecrosis subjects. Our study seems in agreement with the hypothesis that BPs can inhibit angiogenesis interfering with endothelial cell proliferation and survival, leading to loss of blood vessels and avascular necrosis.

Monoclonal antibodies: potential new therapeutic treatment against multiple myeloma

Despite recent treatments, such as bortezomib, thalidomide, and lenalidomide, therapy of multiple myeloma (MM) is limited, and MM remains an incurable disease associated with high mortality. The outcome of patients treated with cytotoxic therapy has not been satisfactory. Therefore, new therapies are needed for relapsed MM. A new anticancer strategy is the use of monoclonal antibodies (MoAbs) that represent the best available combination of tumor cytotoxicity, environmental signal privation, and immune system redirection. Clinical results in patients with relapsed/refractory MM suggest that MoAbs are likely to operate synergistically with traditional therapies (dexamethasone), immune modulators (thalidomide, lenalidomide), and other novel therapies (bortezomib); in addition, MoAbs have shown the ability to overcome resistance to these therapies. It remains to be defined how MoAb therapy can most fruitfully be incorporated into the current therapeutic paradigms that have achieved significant survival earnings in patients with MM. This will require careful consideration of the optimal sequence of treatments and their clinical position as either short‐term induction therapy, frontline therapy in patients ineligible for ASCT, or long‐term maintenance treatment.

Novel therapeutic strategies in multiple myeloma: role of the heat shock protein inhibitors

Despite advances in understanding the molecular pathogenesis of multiple myeloma and promising new therapies, almost all patients eventually relapse with resistant disease. There is therefore a strong rationale for combining novel therapies that target intrinsic molecular pathways mediating multiple myeloma cell resistance. One such protein family is the heat shock proteins (HSP), especially the HSP90 family. Heat shock protein inhibitors have been identified as promising cancer treatments as, while they only inhibit a single biologic function, the chaperone–protein association, their effect is widespread as it results in the destruction of numerous client proteins. This article reviews the preclinical and clinical data, which support the testing of HSP90 inhibitors as cancer drugs and update the reader on the current status of the ongoing clinical trials of HSP90 inhibitors in multiple myeloma.

Nanoparticles in Oncology: The New Theragnostic Molecules

Cancer nanotherapeutics have shown promise in resolving some of the limitations of conventional drug delivery systems such as nonspecific biodistribution and targeting, lack of water solubility, low therapeutic indices, and poor oral bioavailability. Moreover, cancer nanotechnology has the potential of improving current approaches to cancer detection, diagnosis, and imaging. Recently, nanotechnology and molecular imaging have been combined to generate nanoparticles that simultaneously facilitate cancer therapy and diagnosis, the so called theragnostic nanoparticles. The aim of our review is to highlight recent developments within the context of the current knowledge of nanotechnology, to recall the experimental steps that have brought to the clinical development and application of nanoparticles, and explain the biological rationale for their use with oncologic patients. In particular, we summarize recent findings with respect to possible new applications for therapy and diagnosis, and their specific properties. Moreover, we report the more recent prospects in gene therapy, the possibility of using new drug delivery methods, the action of nanoparticles on the immune system and apoptosis, and the concrete possibility of detecting and characterizing circulating tumor cells or of developing new technologies in drug discovery.

Evaluation of circulating endothelial cells, VEGF and VEGFR2 serum levels in patients with chronic myeloproliferative diseases

Authors evaluated some markers of angiogenetic activity in patients with chronic myeloproliferative diseases (CMDs). In this study by using a cytofluorimetric analysis we evaluated circulating endothelial progenitor cells (EPCs) in patients with chronic myeloproliferative disease. Moreover, in the same group of subjects, we evaluated serum levels of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor‐2 (VEGFR2). In our patients, we have found an increase in the number of endothelial progenitor cells in primary myelofibrosis (PMF) and polycythaemia vera (PV) patients, while an increase of circulating endothelial cells (CECs) was found in all patients with CMD. Moreover, we found higher serum levels of VEGF with respect to control subjects in every group of patients with CMD, and a not significant reduction of VEGFR2 levels in essential thrombocythaemia (ET) patients. A correlation was also found in PV patients between VEGF levels and erythrocyte number and in PMF subjects with the count of white cells. Our data suggest that some markers of angiogenesis are activated in CMD patients and angiogenesis may have a role in the pathophysiology of chronic myeloproliferative disorders. Copyright

Increased serum levels of neutrophil gelatinase-associated lipocalin in patients with essential thrombocythemia and polycythemia vera

Neutrophil gelatinaase-associated lipocalin (NGAL) is a glycoprotein bound with matrix metalloproteinase-9 (MMP-9) in human neutrophils, and elevated tissue NGAL expression has been documented in different infectious and inflammatory conditions. Recent evidence suggests that NGAL expression is induced in many types of human cancer. Moreover, NGAL is required for BCR–ABL-induced tumorigenesis. The aim of the present study was to measure serum levels of NGAL in patients with essential thrombocythemia (ET) and polycythemia vera (PV). We also evaluated NGAL levels in patients with ET and PV with and without thrombotic events, to explore a possible correlation of NGAL with platelet and leukocyte activation, and in patients with sepsis. Serum NGAL levels in the study population were significantly higher than in healthy adults and in subjects with sepsis. A correlation between NGAL and the number of white cells and neutrophils was found in patients with PV and ET. NGAL serum levels were not different depending on the presence or not of the JAK2 mutation, and a mutant allele dosage effect was not observed for NGAL levels. Patients with PV and ET with thrombosis did not have significantly higher levels of NGAL. We were unable to demonstrate a significant association between serum NGAL levels and CD11b or CD62 expression. In conclusion, our study reports evidence demonstrating that increased levels of NGAL appear to be a characteristic of patients with PV and ET.

Epigenetic therapy in myelodysplastic syndromes

The wide spectrum of clonal hematopoietic disorders that fall under the broad diagnostic category of myelodysplastic syndromes (MDS) consist of a family of bone marrow malignancies – with ineffective, inadequate, and dysplastic hematopoiesis, and with an increased risk of life‐threatening infections, bleeding, and progression to acute myeloid leukemia (AML) – that are characterized by a deep heterogeneity on the clinical, biologic and prognostic level. The intrinsic complexity of this group of disorders and the frequent association with one or more comorbidities have limited for many years the number of effective treatment options available: most patients are, indeed, still managed by supportive care measures, with just a minority of them being eligible for allogeneic stem cell transplantation, which is still the only potentially curative modality. In the last two decades, the progressively better understanding of MDS biology has shown how an abnormal epigenetic modulation might play a crucial part in the pathogenesis and in the process of biologic evolution of these disorders. Moreover, pharmacological agents that target the so‐called epigenome have shown a significant clinical activity for diverse hematologic malignancies, including MDS. The aim of this review is to highlight recent developments within the context of current knowledge of MDS and its altered epigenetic regulation and to recall the experimental steps that have brought to the clinical development and application of epigenetic modifiers, such as azacytidine and decitabine, trying to explain the biologic rationale for their use in this setting.

Increase of novel biomarkers for oxidative stress in patients with plasma cell disorders and in multiple myeloma patients with bone lesions

ObjectivesProtein oxidation plays a key role in the pathogenesis of oncological diseases. In this study, we analyzed the oxidative stress in untreated multiple myeloma (MM) patients and in patients affected by monoclonal gammopathy of uncertain significance (MGUS).MethodsWe evaluated serum levels of advanced oxidation protein products (AOPPs), advanced glycation end products (AGEs), and protein nitrosylation in patients with monoclonal gammopathy and in control subjects.ResultsSerum levels of AOPPs and S-nitrosylated proteins were significantly increased in MM patients in comparison to controls and to MGUS subjects. Moreover, in MM patients the levels of AOPPs, AGEs and S-nitrosylated proteins were significantly higher in patients with bone lesions compared with those without lytic bone lesions.ConclusionsMM is closely associated with oxidative stress and further investigation might provide an insight to understand a putative causal link between oxidative stress and MM disease onset and progression or MM complications.

Changes in advanced oxidation protein products, advanced glycation end products, and s-nitrosylated proteins, in patients affected by polycythemia vera and essential thrombocythemia.

OBJECTIVES Oxidative stress has a clear pro tumoral effect in myeloproliferative neoplasms (MPDs). In this study, we analyzed oxidative stress in patients with essential thrombocythemia (ET) and polycythemia vera (PV). Design and methods We analyzed serum levels of advanced oxidation protein products (AOPPs) degradation, advanced glycation end products (AGEs), and protein nitrosylation in ET and PV patients. We also evaluated neutrophil gelatinase-associated lipocalin (NGAL) levels, an acute phase protein isolated in human neutrophils, the activation status of platelets and leukocytes, and the JAK2 (V617F) mutation status. RESULTS AOPPs and s-nitrosylated proteins were significantly higher in PV and ET subjects as compared to healthy volunteers, while AGEs were higher in ET subjects with respect to controls. Moreover, in PV patients we found a correlation between s-nitrosylated proteins and Hb value. In ET patients AGEs were significantly higher in patients with thrombosis compared with those without thrombotic events. CONCLUSIONS Our results suggest that oxidative stress could play a role in the physiopathology of MPDs and in the onset of myeloproliferative associated thrombotic risk.