Giuliana Gregato

Complementary Populations of Human Adipose CD34+ Progenitor Cells Promote Growth, Angiogenesis, and Metastasis of Breast Cancer

Obesity is associated with an increased frequency, morbidity, and mortality of several types of neoplastic diseases, including postmenopausal breast cancer. We found that human adipose tissue contains two populations of progenitors with cooperative roles in breast cancer. CD45(-)CD34(+)CD31(+)CD13(-)CCRL2(+) endothelial cells can generate mature endothelial cells and capillaries. Their cancer-promoting effect in the breast was limited in the absence of CD45(-)CD34(+)CD31(-)CD13(+)CD140b(+) mesenchymal progenitors/adipose stromal cells (ASC), which generated pericytes and were more efficient than endothelial cells in promoting local tumor growth. Both endothelial cells and ASCs induced epithelial-to-mesenchymal transition (EMT) gene expression in luminal breast cancer cells. Endothelial cells (but not ASCs) migrated to lymph nodes and to contralateral nascent breast cancer lesions where they generated new vessels. In vitro and in vivo, endothelial cells were more efficient than ASCs in promoting tumor migration and in inducing metastases. Granulocyte colony-stimulating factor (G-CSF) effectively mobilized endothelial cells (but not ASCs), and the addition of chemotherapy and/or of CXCR4 inhibitors did not increase endothelial cell or ASC blood mobilization. Our findings suggest that adipose tissue progenitor cells cooperate in driving progression and metastatic spread of breast cancer.

The biguanides metformin and phenformin inhibit angiogenesis, local and metastatic growth of breast cancer by targeting both neoplastic and microenvironment cells

The human white adipose tissue (WAT) contains progenitors with cooperative roles in breast cancer (BC) angiogenesis, local and metastatic progression. The biguanide Metformin (Met), commonly used for Type 2 diabetes, might have activity against BC and was found to inhibit angiogenesis in vivo. We studied Met and another biguanide, phenformin (Phe), in vitro and in vivo in BC models. In vitro, biguanides activated AMPK, inhibited Complex 1 of the respiratory chain and induced apoptosis of BC and WAT endothelial cells. In coculture, biguanides inhibited the production of several angiogenic proteins. In vivo, biguanides inhibited local and metastatic growth of triple negative and HER2+ BC in immune‐competent and immune‐deficient mice orthotopically injected with BC. Biguanides inhibited local and metastatic BC growth in a genetically engineered murine model model of HER2+ BC. In vivo, biguanides increased pimonidazole binding (but not HIF‐1 expression) of WAT progenitors, reduced tumor microvessel density and altered the vascular pericyte/endothelial cell ratio, so that cancer vessels displayed a dysplastic phenotype. Phe was significantly more active than Met both in vitro and in vivo. Considering their safety profile, biguanides deserve to be further investigated for BC prevention in high‐risk subjects, in combination with chemo and/or targeted therapy and/or as post‐therapy consolidation or maintenance therapy for the prevention of BC recurrence.

Miniaturized FISH for screening of onco-hematological malignancies

Fluorescence in situ hybridization (FISH) represents a major step in the analysis of chromosomal aberrations in cancer. It allows the precise detection of specific rearrangements, both for diagnostic and prognostic purposes. Here we present a miniaturized FISH method performed on fresh and fixed hematological samples. This procedure has been developed together with a microfluidic device that integrates cluster-assembled nanostructured TiO2 (ns-TiO2) as a nanomaterial promoting hematopoietic cell immobilization in conditions of shear stress. As a result of miniaturization, FISH can be performed with at least a 10-fold reduction in probe usage and minimal cell requirements, creating the possibility of using FISH in genetic screening applications. We developed the protocol on tumor cells and bone marrow (BM) from a normal donor using commercially sex-specific and onco-hematology probes. The procedure was then validated using either BM or peripheral blood (PB) from six patients with hematological diseases, each associated with different genetic lesions. Miniaturized FISH demonstrated comparable performance to standard FISH, indicating that it is suitable for genetic screenings, in research, and in clinical settings for the diagnosis of samples from onco-hematological malignancies.

Therapeutic Effect of Lenalidomide in a Novel Xenograft Mouse Model of Human Blastic NK Cell Lymphoma/Blastic Plasmacytoid Dendritic Cell Neoplasm

Purpose: Blastic natural killer (NK) cell lymphoma/blastic plasmacytoid dendritic cell neoplasm (BNKL) is a rare and aggressive neoplasia characterized by infiltration of blast CD4+/CD56+ cells in the skin, the bone marrow, and peripheral blood. Currently, more efforts are required to better define molecular and biological mechanisms associated with this pathology. To the best of our knowledge, no mouse model recapitulated human BNKL so far. Experimental Design: Primary bone marrow cells from a BNKL patient were injected in nonobese diabetes/severe combined immunodeficient interleukin (IL) 2rγ−/− mice with the intent to generate the first BNKL orthotopic mouse model. Moreover, because of the lack of efficient treatments for BNKL, we treated mice with lenalidomide, an immunomodulatory and antiangiogenic drug. Results: We generated in mice a fatal disease resembling human BNKL. After lenalidomide treatment, we observed a significant reduction in the number of peripheral blood, bone marrow, and spleen BNKL cells. Tumor reduction parallels with a significant decrease in the number of circulating endothelial and progenitor cells and CD31+ murine endothelial cells. In mice treated with lenalidomide, BNKL levels of active caspase-3 were significantly augmented, thus showing proapoptotic and cytotoxic effects of this drug in vivo. An opposite result was found for proliferating cell nuclear antigen, a proliferation marker. Conclusions: Our BNKL model might better define the cellular and molecular mechanisms involved in this disease, and lenalidomide might be considered for the future therapy of BNKL patients. Clin Cancer Res; 17(19); 6163–73. ©2011 AACR.

Rituximab and subcutaneous cladribine in chronic lymphocytic leukemia for newly diagnosed and relapsed patients.

The aim of this study was to investigate the efficacy of combined treatment with rituximab and subcutaneous cladribine in patients with newly diagnosed and relapsed chronic lymphocytic leukemia (CLL). Forty-three patients with active CLL or small lymphocytic lymphoma received rituximab 375 mg/m2 on day 1 and cladribine 0.1 mg/kg subcutaneously on days 2–6. The treatment was repeated every 4 weeks for a total of four cycles. Sixteen patients were pretreated. The overall response rate was 88% (50% complete remission and 38% partial remission). The median time to treatment failure was 37.9 months. Grade 4 neutropenia developed in 5% of patients. The data indicate that combination therapy with rituximab and cladribine is a valuable and safe treatment for patients with CLL.

Pharmacological Inhibition of Necroptosis Protects from Dopaminergic Neuronal Cell Death in Parkinson’s Disease Models

Summary Dysfunctions in mitochondrial dynamics and metabolism are common pathological processes associated with Parkinson’s disease (PD). It was recently shown that an inherited form of PD and dementia is caused by mutations in the OPA1 gene, which encodes for a key player in mitochondrial fusion and structure. iPSC-derived neural cells from these patients exhibited severe mitochondrial fragmentation, respiration impairment, ATP deficits, and heightened oxidative stress. Reconstitution of normal levels of OPA1 in PD-derived neural cells normalized mitochondria morphology and function. OPA1-mutated neuronal cultures showed reduced survival in vitro. Intriguingly, selective inhibition of necroptosis effectively rescued this survival deficit. Additionally, dampening necroptosis in MPTP-treated mice protected from DA neuronal cell loss. This human iPSC-based model captures both early pathological events in OPA1 mutant neural cells and the beneficial effects of blocking necroptosis, highlighting this cell death process as a potential therapeutic target for PD.

Aspirin and atenolol enhance metformin activity against breast cancer by targeting both neoplastic and microenvironment cells

Metformin can induce breast cancer (BC) cell apoptosis and reduce BC local and metastatic growth in preclinical models. Since Metformin is frequently used along with Aspirin or beta-blockers, we investigated the effect of Metformin, Aspirin and the beta-blocker Atenolol in several BC models. In vitro, Aspirin synergized with Metformin in inducing apoptosis of triple negative and endocrine-sensitive BC cells, and in activating AMPK in BC and in white adipose tissue (WAT) progenitors known to cooperate to BC progression. Both Aspirin and Atenolol added to the inhibitory effect of Metformin against complex I of the respiratory chain. In both immune-deficient and immune-competent preclinical models, Atenolol increased Metformin activity against angiogenesis, local and metastatic growth of HER2+ and triple negative BC. Aspirin increased the activity of Metformin only in immune-competent HER2+ BC models. Both Aspirin and Atenolol, when added to Metformin, significantly reduced the endothelial cell component of tumor vessels, whereas pericytes were reduced by the addition of Atenolol but not by the addition of Aspirin. Our data indicate that the addition of Aspirin or of Atenolol to Metformin might be beneficial for BC control, and that this activity is likely due to effects on both BC and microenvironment cells.

A Subpopulation of Circulating Endothelial Cells Express CD109 and is Enriched in the Blood of Cancer Patients

Background The endothelium is not a homogeneous organ. Endothelial cell heterogeneity has been described at the level of cell morphology, function, gene expression, and antigen composition. As a consequence of the genetic, transcriptome and surrounding environment diversity, endothelial cells from different vascular beds have differentiated functions and phenotype. Detection of circulating endothelial cells (CECs) by flow cytometry is an approach widely used in cancer patients, and their number, viability and kinetic is a promising tool to stratify patient receiving anti-angiogenic treatment. Methodology/Principal Findings Currently CECs are identified as positive for a nuclear binding antigen (DNA+), negative for the pan leukocyte marker CD45, and positive for CD31 and CD146. Following an approach recently validated in our laboratory, we investigated the expression of CD109 on CECs from the peripheral blood of healthy subject and cancer patients. The endothelial nature of these cells was validated by RT-PCR for the presence of m-RNA level of CDH5 (Ve-Cadherin) and CLDN5 (Claudin5), two endothelial specific transcripts. Before treatment, significantly higher levels of CD109+ CECs and viable CD109+CECs were found in breast cancer patients and glioblastoma patients compared to healthy controls, and their number significantly decreased after treatment. Higher levels of endothelial specific transcripts expressed in developing endothelial cells CLEC14a, TMEM204, ARHGEF15, GPR116, were observed in sorted CD109+CECs when compared to sorted CD146+CECs, suggesting that these genes can play an important role not only during embryogenesis but also in adult angiogenesis. Interestingly, mRNA levels of TEM8 (identified as Antrax Toxin Receptor1, Antrax1) were expressed in CD109+CECs+ but not in CD146+CECs. Conclusion Taken together our results suggest that CD109 represent a rare population of circulating tumor endothelial cells, that play a potentially useful prognostic role in patients with glioblastoma. The role of CD109 expression in cancer vessel-specific endothelial cells deserves to be further investigated by gene expression studies.

Abstract 5214: Synergistic activity of aspirin, atenolol and metformin in the inhibition of angiogenesis, local and metastatic growth of breast cancer by targeting both neoplastic and microenvironment cells

We have recently described that the human white adipose tissue (WAT) contains progenitors with cooperative roles in breast cancer (BC) angiogenesis, local and metastatic progression (Martin-Padura et al, 2012; Orecchioni et al, 2013). The biguanide metformin (met), commonly used for type 2 diabetes, might have activity against BC and we found it able to inhibit angiogenesis in vivo (Dallaglio et al, 2014; Orecchioni et al, 2014). We studied met and another biguanide, phenformin (phe), in vitro and in vivo in orthotopic NSG murine models of local and metastatic BC. As met is frequently administered with aspirin or atenolol in diabetic/obese patients, we studied in vitro and vivo their association. In vitro, biguanides activated AMPK, inhibited complex 1 of the respiratory chain and induced apoptosis of BC and WAT endothelial cells. Aspirin was synergistic with met and phe in inducing apoptosis of estrogen receptor+ BC cells. This synergistic effect was less evident in triple negative BC cells. In co-culture, biguanides significantly inhibited the production of several angiogenic proteins. In vivo, biguanides inhibited local and metastatic growth of triple negative and HER2+ BC in immune-competent and immune-deficient mice orthotopically injected with BC. Biguanides also inhibited local and metastatic BC growth in a genetically engineered model of HER2+ BC. In vivo, biguanides increased pimonidazole binding (but not HIF-1 expression) of WAT progenitors, reduced tumor microvessel density and impaired of the vascular pericyte/endothelial cell ratio, so that cancer vessels displayed a dysplastic phenotype. This effect was significantly increased by the addition of aspirin or atenolol. This was evident also when AMPK activation was assessed in combination therapy regimens. AMPK phosphorylation was significantly increased in BC cells treated with met+aspirin or phe+atenolol as compared to met or phe alone. In WAT progenitors, AMPK activation was enhanced only under met+aspirin and met+atenolol combinations. In immune-competent mice, met effect in BC models was significantly enhanced by the addition of atenolol or of aspirin. Phe was significantly more active than met both in vitro and in vivo. Considering their safety profile, biguanides (alone or in combination with aspirin or atenolol) deserve to be further investigated for BC prevention in high-risk subjects, in combination with chemo and/or targeted therapy and/or as post-therapy consolidation or maintenance therapy for the prevention of BC recurrence. Citation Format: Giovanna Talarico, Francesca Reggiani, Stefania Orecchioni, Patrizia Mancuso, Angelica Calleri, Giuliana Gregato, Valentina Labanca, Douglas M. Noonan, Katiuscia Dallaglio, Adriana Albini, Francesco Bertolini. Synergistic activity of aspirin, atenolol and metformin in the inhibition of angiogenesis, local and metastatic growth of breast cancer by targeting both neoplastic and microenvironment cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5214. doi:10.1158/1538-7445.AM2015-5214

Molecular investigation of coexistent chronic myeloid leukaemia and peripheral T-cell lymphoma-a case report

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm underlain by the formation of BCR-ABL1 – an aberrant tyrosine kinase – in the leukaemic blasts. Long-term survival rates in CML prior to the advent of tyrosine kinase inhibitors (TKIs) were dismal, albeit the incidence of secondary malignancies was higher than that of age-matched population. Current figures confirm the safety of TKIs with conflicting data concerning the increased risk of secondary tumours. We postulate that care has to be taken when distinguishing between coexisting, secondary-to-treatment and second in sequence, but independent tumourigenic events, in order to achieve an unbiased picture of the adverse effects of novel treatments. To illustrate this point, we present a case of a patient in which CML and peripheral T-cell lymphoma (PTCL) coexisted, although the clinical presentation of the latter followed the achievement of major molecular response of CML to TKIs.