Dampening of cytotoxic innate lymphoid cells: A new tumour immune escape mechanism in B cell non-Hodgkin's lymphoma.

The role and regulation of innate immune cells is poorly understood in B-cell non-Hodgkin lymphoma (NHL). As natural killer (NK) cells, helper innate lymphoid cells (ILCs) are lymphocytes endowed with either anti- or pro-tumour activity and involved in inflammatory processes. In our ex vivo analysis of NK cells and ILCs from NHL patients, we observed that, in comparison to healthy donors (HD), the frequency of the cytotoxic subset of NK cells, the CD16+ NK, decreased in patients' peripheral blood. In general, circulating NK cells showed a pro-tumorigenic phenotype, while ILCs displayed a more activated/cytotoxic phenotype. Conversely, at the tumour site, in patients' lymph nodes, ILCs showed a low expression of granzyme.In vitromixed lymphocyte-tumour cell cultures with HD PBMCs and NHL cell lines demonstrated that ILC cytotoxic potential was lowered by the presence of tumour cells but, in the absence of T regulatory cells (Tregs), their cytolytic potential was recovered. Our data shed novel light on dysfunctional innate immunity in NHL. We suggest a new mechanism of tumour immuno-escape based on the reduction of cell cytotoxicity involving ILCs and likely controlled by Tregs.

Vinorelbine, cyclophosphamide and 5-FU effects on the circulating and intratumoural landscape of immune cells improve anti-PD-L1 efficacy in preclinical models of breast cancer and lymphoma.

BACKGROUND: Anti-PD-1 and anti-PD-L1 checkpoint inhibitors (CIs) are clinically active in many types of cancer. However, only a minority of patients achieve a complete and/or long-lasting clinical response. We studied the effects of different doses of three widely used, orally active chemotherapeutics (vinorelbine, cyclophosphamide and 5-FU) over local and metastatic tumour growth, and the landscape of circulating and tumour-infiltrating immune cells involved in CI activity. METHODS: Immunocompetent Balb/c mice were used to generate models of breast cancer (BC) and B-cell lymphoma. Vinorelbine, cyclophosphamide and 5-FU (alone or in combination with CIs), were given at low-dose metronomic, medium, or maximum tolerable dosages. RESULTS: Cyclophosphamide increased circulating myeloid derived suppressor cells (MDSC). Vinorelbine, cyclophosphamide and 5-FU reduced circulating APCs. Vinorelbine and cyclophosphamide (at medium/high doses) reduced circulating Tregs. Cyclophosphamide (at low doses) and 5-FU (at medium doses) slightly increased circulating Tregs. Cyclophosphamide was the most potent drug in reducing circulating CD3+CD8+ and CD3+CD4+ T cells. Vinorelbine, cyclophosphamide and 5-FU reduced the number of circulating B cells, with cyclophosphamide showing the most potent effect. Vinorelbine reduced circulating NKs, whereas cyclophosphamide and 5-FU, at low doses, increased circulating NKs. In spite of reduced circulating T, B and NK effector cells, preclinical synergy was observed between chemotherapeutics and anti-PD-L1. Most-effective combinatorial regimens where associated with neoplastic lesions enriched in B cells, and, in BC-bearing mice (but not in mice with lymphoma) also in NK cells. CONCLUSIONS: Vinorelbine, cyclophosphamide and 5-FU have significant preclinical effects on circulating and tumour-infiltrating immune cells and can be used to obtain synergy with anti-PD-L1.

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.

The multifaceted circulating endothelial cell in cancer: towards marker and target identification.

Increases in the number of circulating endothelial cells (CECs) and progenitors (CEPs) have been reported in various pathological conditions including cancer. Preclinical studies have shown that CEC and CEP kinetics correlate well with several standard laboratory angiogenesis assays, which cannot be used in humans. At the clinical level, evidence is emerging that CEC kinetics and viability might correlate with clinical outcomes in cancer patients who undergo anti-angiogenic treatment. Therefore, CEC and CEP measurement has potential as a surrogate marker for monitoring anti-angiogenic treatment and drug activity, and could help to determine the optimal biological dose of anti-angiogenic drugs, which are being used with increasing frequency in medical oncology.

Vinorelbine and Intermittent Cyclophosphamide Sensitize an Aggressive Myc-Driven B-Cell Lymphoma to Anti-PD-1 by an Immunological Memory Effective against Tumor Re-Challenge.

We have previously shown in triple-negative breast cancer (TNBC) models that a triple therapy (TT) including intermittent cyclophosphamide (C), vinorelbine (V), and anti-PD-1 activates antigen-presenting cells (APC) and generates stem like-T cells able to control local and metastatic tumor progression. In the present manuscript, we report the generation of a highly aggressive, anti-PD-1 resistant model of a high-grade, Myc-driven B-cell non-Hodgkin's lymphoma (NHL) that can be controlled in vivo by TT but not by other chemotherapeutic agents, including cytarabine (AraC), platinum (P), and doxorubicin (D). The immunological memory elicited in tumor-bearing mice by TT (but not by other treatments) can effectively control NHL re-challenge even at very high inoculum doses. TT re-shaped the landscape of circulating innate NK cells and adaptive immune cells, including B and T cells, and significantly reduced exhausted CD4+ and CD8+ TIM3+PD-1+ T cells in the spleens of treated mice.

Diagnostic Performance and Cell Count of EBUS-TBNA Needle Gauges: A Prospective Trial.

BACKGROUND: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a well-established diagnostic procedure for evaluating hilar and mediastinal lymphadenopathies and is the gold standard for lung cancer diagnosis and staging. Recent studies assessed the effectiveness of the 19-G flex needle in obtaining larger EBUS-TBNA samples, and prospective small series gave similar results in terms of diagnostic yield when testing different gauge needles. The lack of homogeneity between series and the small sample size of some prospective cohorts poses a limit to the validity of those results. This prospective controlled study compared the 19-G flex and 22-G needles in terms of diagnostic yield. An objective laboratory method was used to count cells and compare the two needles' cytologic yields. MATERIAL: A prospective controlled study was conducted on 90 patients undergoing EBUS-TBNA for the diagnosis of hilar and mediastinal lymphadenopathies. The institutional ethic committee (IEO573) approved the study, and informed consent was obtained from all patients. RESULTS: A total of 90 patients were enrolled in this study, 84.4% of whom were diagnosed with malignancy and 15.6% with non-neoplastic disease. Sensitivity for malignancy was 93.4% (CI: 87.4-97.1%) for the 19-G needle and 92.6% (CI: 86.3-96.5%) for the 22-G needle (p = 0.80). The percentage of malignant cells in the cell block was 63.9% and 61.5% for the 22-G and 19-G needles, respectively. The cell count assessed by flow cytometry was 2071 cells/µL (IQR: 600,2265) with the 22-G needle and 2761 cells/µL (IQR: 505,3250) with the 19-G needle (p = 0.79). The malignant cell count was 0.05 × 103 cells/µL with the 22-G and 0.08 × 103 cells/µL with the 19-G needle (p = 0.70). There was no difference in the presence of tissue cores in the samples, and rapid on-site evaluation (ROSE) cellularity was comparable between the two needles. CONCLUSIONS: The 19-G flex EBUS-TBNA needle is comparable to the 22-G needle in terms of diagnostic yield for cyto-histological evaluation of hilar and mediastinal lymphadenopathies. There is no difference between the 19-G and 22-G needle cell counts evaluated by flow cytometry.

Circulating endothelial cells and circulating endothelial progenitors.

The roles of circulating endothelial cells (CECs) and circulating endothelial progenitors (CEPs) are currently being investigated in several diseases including cancer and metastases development. Preclinical and clinical data suggest that CEC enumeration might be useful to identify patients who might benefit from anti-angiogenic treatments while CEPs seem to have a "catalytic" role in different steps of cancer progression and recurrence after therapy. The definition of CEC and CEP phenotypes and the standardization of CEC and CEP enumeration procedures are highly warranted to use these cells as biomarkers in clinical trials in oncology, and to compare results from different studies.

A single-cell transcriptomic landscape of innate and adaptive intratumoral immunity in triple negative breast cancer during chemo- and immunotherapies.

Breast cancer (BC) constitutes a major health problem worldwide, making it the most common malignancy in women. Current treatment options for BC depend primarily on histological type, molecular markers, clinical aggressiveness and stage of disease. Immunotherapy, such as αPD-1, have shown combinatorial clinical activity with chemotherapy in triple negative breast cancer (TNBC) delineating some therapeutic combinations as more effective than others. However, a clear overview of the main immune cell populations involved in these treatments has never been provided.Here, an assessment of the immune landscape in the tumor microenvironment (TME) of two TNBC mouse models has been performed using single-cell RNA sequencing technology. Specifically, immune cells were evaluated in untreated conditions and after treatments with chemotherapy or immunotherapy used as single agents or in combination. A decrease of Treg was found in treatments with in vivo efficacy as well as γδ T cells, which have a pro-tumoral activity in mice. Focusing on Cd8 T cells, across all the conditions, a general increase of exhausted-like Cd8 T cells was confirmed in pre-clinical treatments with low efficacy and an opposite trend was found for the proliferative Cd8 T cells. Regarding macrophages, M2-like cells were enriched in treatments with low efficacy while M1-like macrophages followed an opposite trend. For both models, similar proportions of B cells were detected with an increase of proliferative B cells in treatments involving cisplatin in combination with αPD-1. The fine-scale characterization of the immune TME in this work can lead to new insights on the diagnosis and treatment of TNBC.

Addressing the Role of Angiogenesis in Patients with Advanced Pancreatic Neuroendocrine Tumors Treated with Everolimus: A Biological Prospective Analysis of Soluble Biomarkers and Clinical Outcomes.

BACKGROUND: The success of targeted therapies in the treatment of pancreatic neuroendocrine tumors has emphasized the strategy of targeting angiogenesis and the PI3K/AKT/mTOR pathway. However, the major challenge in the targeted era remains the early identification of resistant tumors especially when the efficacy is rarely associated to a clear tumor shrinkage at by imaging assessment. METHODS: In this prospective study (NCT02305810) we investigated the predictive and prognostic role of soluble biomarkers of angiogenesis turnover (VEGF, bFGF, VEGFR2, TSP-1) circulating endothelial cells and progenitors, in 43 patients with metastatic panNET receiving everolimus. RESULTS: Among all tested biomarkers, we found a specific subpopulation of circulating cells, CD31+CD140b-, with a significantly increased tumor progression hazard for values less or equal to the first quartile. CONCLUSION: Our study suggested the evidence that circulating cells might be surrogate biomarkers of angiogenesis activity in patients treated with everolimus and their baseline levels can be correlated with survival. However, further studies are now needed to validate the role of these cells as surrogate markers for the selection of patients to be candidates for antiangiogenic treatments.

Circulating perivascular progenitors: a target of PDGFR inhibition.

Cancer blood vessels consist of two interacting types of cells: inner lining endothelial cells (ECs) and surrounding perivascular cells (pericytes, vascular smooth muscle cells or mural cells). PDGFRbeta(CD140b)+ progenitor perivascular cells (PPC) can differentiate into pericytes and regulate vessel stability and vascular survival in tumors. Similarly to what we have done with circulating ECs and progenitors, we developed a flow cytometry procedure for the enumeration of circulating PPCs and the study of their viability in murine models of cancer and in cancer patients. DNA+CD45-CD31-CD140b+ cells were enumerated by six-colour flow cytometry, their morphology was studied by electron microscopy, PPC specificity confirmed by reverse trascription-PCR (RT-PCR) expression of CD140b mRNA, and viability assessed by Syto16 and 7AAD. In preclinical marrow transplantation studies, 9 ± 4% of circulating PPCs were derived from the marrow donor. PPCs were increased in cancer-bearing mice and in patients affected by some types of cancer. At variance with the kinetic of circulating endothelial progenitors, high-dose cyclophosphamide reduced the number of viable PPCs. The administration of sunitinib, a drug known to inhibit PDGFR, was associated in murine models and in cancer patients with an increase of apoptotic/necrotic circulating PPC, suggesting a direct targeting of these cells. PPC enumeration might be studied as a tool for the definition of the optimal biologic dose of anti-PDGFR drugs and investigated clinically as a possible predictive/prognostic tool in patients receiving anti-PDGFR drugs.

Cyclophosphamide and Vinorelbine Activate Stem-Like CD8+ T Cells and Improve Anti-PD-1 Efficacy in Triple-Negative Breast Cancer.

Checkpoint inhibitors (CI) instigate anticancer immunity in many neoplastic diseases, albeit only in a fraction of patients. The clinical success of cyclophosphamide (C)-based haploidentical stem-cell transplants indicates that this drug may re-orchestrate the immune system. Using models of triple-negative breast cancer (TNBC) with different intratumoral immune contexture, we demonstrate that a combinatorial therapy of intermittent C, CI, and vinorelbine activates antigen-presenting cells (APC), and abrogates local and metastatic tumor growth by a T-cell-related effect. Single-cell transcriptome analysis of >50,000 intratumoral immune cells after therapy treatment showed a gene signature suggestive of a change resulting from exposure to a mitogen, ligand, or antigen for which it is specific, as well as APC-to-T-cell adhesion. This transcriptional program also increased intratumoral Tcf1+ stem-like CD8+ T cells and altered the balance between terminally and progenitor-exhausted T cells favoring the latter. Overall, our data support the clinical investigation of this therapy in TNBC. SIGNIFICANCE: A combinatorial therapy in mouse models of breast cancer increases checkpoint inhibition by activating antigen-presenting cells, enhancing intratumoral Tcf1+ stem-like CD8+ T cells, and increasing progenitor exhausted CD8+ T cells.

The multiple personality disorder phenotype(s) of circulating endothelial cells in cancer.

Circulating endothelial cells (CECs) and circulating endothelial progenitors (CEPs) are currently being investigated in a variety of diseases as markers of vascular turnover or damage and, also in the case of CEPs, vasculogenesis. CEPs appear to have a "catalytic" role in different steps of cancer progression and recurrence after therapy, and there are preclinical and clinical data suggesting that CEC enumeration might be useful to select and stratify patients who are candidates for anti-angiogenic treatments. In some types of cancer, CECs and CEPs might be one of the possible hidden identities of cancer stem cells. The definition of CEC and CEP phenotype and the standardization of CEC and CEP enumeration strategies are highly desirable goals in order to exploit these cells as reliable biomarkers in oncology clinical trials.

Circulating endothelial cells as biomarkers in clinical oncology.

Circulating endothelial cells (CECs) and circulating endothelial progenitors (CEPs) play a different role in cancer development, acting as possible markers of vascular turnover/damage (CECs) and vasculogenesis (CEPs). Preclinical and clinical data suggest that CEC enumeration might be useful to define the best treatment option for patients who are candidate to anti-angiogenic therapy, while CEPs seem to have a "catalytic" role in different steps of cancer progression and recurrence after therapy. The definition of CEC and CEP phenotype and the standardization of CEC and CEP enumeration procedures are highly warranted to use these cells as biomarkers in clinical trials in oncology, and to compare results from different studies.

If it is in the marrow, is it also in the blood? An analysis of 1,000 paired samples from patients with B-cell non-Hodgkin lymphoma.

BACKGROUND: Staging of B-cell non Hodgkin's lymphoma (NHL) routinely involves bone marrow (BM) examination by trephine biopsy (BM-TB). The evidence of disease in the BM-TB results in a clinical stage IV classification affecting therapeutic strategies for NHL patients. BM immunophenotyping by flow cytometry (FC) is also used, although its clinical value is still under debate. METHODS: Using FC we analyzed 1,000 paired BM aspirates and peripheral blood (PB) samples from 591 NHL patients to investigate the concordance between BM and PB. B-lymphocytes were defined monoclonal when a ratio of 0.3 < κ/l > 3 was observed. Aberrant immunophenotypes present in the B-cell subpopulation were also investigated. BM-TB was also performed in 84.1% of samples (841/1000), and concordance between BM-TB and BM-FC was evaluated. Concordance was defined as the presence of a positive (in terms of disease detection) or negative result in both BM-FC and PB-FC or BM-TB and BM-FC. RESULTS: Using FC, the overall concordance between BM and PB was 95%. Among the discordant cases (ie presence of neoplastic B-lymphocyte in the BM but under the sensibility of the technique in the PB) the most frequent diagnosis was Waldenstrom's macroglobulinemia (WM, accounting for 20.8% of all discordant cases). The expression of CXCR4, a receptor involved in B-cell trafficking and homing, was found to be down regulated in WM compared to other NHL types, thus suggesting a possible role of CXCR4 in WM cell homing in the BM. WM excluded, FC investigation of BM and PB in NHL patients gives overlapping information.BM involvement was observed by FC in 38% of samples, and concordance between BM-FC and BM-TB was 85%. CONCLUSIONS: The finding that FC data from BM and PB samples overlap in NHL might have major implications for the design of future clinical studies and for patients' follow-up.

Validation of a standardized method for enumerating circulating endothelial cells and progenitors: flow cytometry and molecular and ultrastructural analyses.

PURPOSE: Antigenic overlap among circulating endothelial cells (CEC) and progenitors (CEP), platelets, and other blood cells led to the need to develop a reliable standardized method for CEC and CEP quantification. These cells are emerging as promising preclinical/clinical tools to define optimal biological doses of antiangiogenic therapies and to help stratify patients in clinical trials. EXPERIMENTAL DESIGN: We report the experimental validation of a novel flow cytometry method that precisely dissects CEC/CEP from platelets and other cell populations and provides information about CEC/CEP viability. RESULTS: Sorted DNA/Syto16(+)CD45(-)CD31(+)CD146(+) CECs, investigated by electron microscopy, were found to be bona fide endothelial cells by the presence of Weibel-Palade bodies. More than 75% of the circulating mRNAs of the endothelial-specific gene, VE-cadherin, found in the blood were present in the sorted population. CECs were 140 +/- 171/mL in healthy subjects (n = 37) and 951 +/- 1,876/mL in cancer patients (n = 78; P < 0.0001). The fraction of apoptotic/necrotic CECs was 77 +/- 14% in healthy subjects and 43 +/- 23% in cancer patients (P < 0.0001). CEPs were 181 +/- 167/mL in healthy donors and 429 +/- 507/mL in patients (P = 0.00019). Coefficients of variation were 4 +/- 4% (intrareader), 17 +/- 4% (interreader), and 17 +/- 7% (variability over 0-72 h), respectively. Parallel samples were frozen by a standardized protocol. After thawing, coefficients of variation were 12 +/- 8% (intrareader), 16 +/- 10% (interreader), and 26 +/- 16% (variability over 0-14 days of frozen storage), respectively. CONCLUSIONS: This procedure enumerates a truly endothelial cell population with limited intrareader and interreader variability. It appears possible to freeze samples for large-scale CEC enumeration during clinical trials. This approach could be enlarged to investigate other angiogenic cell populations as well.

Circulating endothelial progenitors are increased in COVID-19 patients and correlate with SARS-CoV-2 RNA in severe cases.

BACKGROUND: During the course of COVID-19, the disease caused by the new coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), thrombotic phenomena and/or diffuse vascular damage are frequent, and viral elements have been observed within endothelial cells. OBJECTIVES: CD146 + circulating endothelial cells (CD146 + CECs) and their progenitors (CEPs) are increased in cardiovascular, thrombotic, infectious, and cancer diseases. The present study was designed to investigate their kinetics in novel coronavirus (COVID-19) patients. METHODS: We used a validated flow cytometry procedure to enumerate viable and apoptotic CD146 + CECs and CEPs in COVID-19 patients during the course of the disease and in patients who recovered. RESULTS: Viable CEPs per milliliter were significantly increased in COVID-19 patients compared with healthy controls. This increase was observed in patients with mild symptoms and not further augmented in patients with severe symptoms. In patients who recovered, CEPs decreased, but were in a range still significantly higher than normal controls. Regarding mature CD146 + CECs, in COVID-19 patients, their absolute number was similar to those observed in healthy controls, but the viable/apoptotic CD146 + CEC ratio was significantly different. Both mild and severe COVID-19 patients had significantly less apoptotic CD146 + CECs compared with healthy controls. Patients who recovered had significantly less CD146 + CECs per milliliter when compared with controls as well as to mild and severe COVID-19 patients. A positive correlation was found between the copies of SARS-CoV-2 RNA in the cellular fraction and apoptotic CEPs per milliliter in severe COVID-19 patients. CONCLUSIONS: CD146 + CECs and CEPs might be investigated as candidate biomarkers of endothelial damage in COVID-19 patients.

Safety, tolerability and biological effects of long-term metronomic administration of non-cytotoxic anti-angiogenic agents.

BACKGROUND: alpha-Interferon, thalidomide and celecoxib inhibit tumour angiogenesis by differing mechanisms. PATIENTS AND METHODS: In a randomized phase II trial to assess tolerability and safety, we assigned patients with advanced slow-growing solid tumours to 1 of 6 two- or three-drug combinations: alpha-interferon 0.5 million IU b.i.d., thalidomide (100 mg b.i.d. reduced to 100 mg daily), or celecoxib (400 mg daily reduced to 200 mg). Circulating endothelial cells and progenitors (CECs, CEPs) and vascular endothelial growth factor were also studied. RESULTS: From January 2002 to September 2005, 62 patients were enrolled. Four months after initiating treatment, 3 (4%) had partial response, 40 (64%) had stable disease and 19 (30%) had disease progression. Median duration of clinical benefit (partial response/stable disease) was 11.3 months. Patients receiving a third drug had significantly less stable disease plus partial response (chi(2) test, p = 0.002) than those receiving two drugs. The treatments were generally well tolerated, but neurotoxicity (G3 lethargy) occurred in 6 patients. Baseline CEPs were lower (p = 0.004) in patients with clinical benefit at 6 months than those without benefit. After 2 months of treatment CECs were lower than at baseline (p = 0.018) in patients without clinical benefit, and CEPs were higher than at baseline (p = 0.003) in patients with benefit. CONCLUSIONS: In pretreated patients with advanced slow-growing solid tumours, long-term metronomic administration of two-drug combinations of alpha-interferon, thalidomide or celecoxib was well tolerated and had antitumour activity. Low baseline CEPs in patients with subsequent clinical benefit suggest that CEC count may identify patients likely to benefit from long-term metronomic anti-angiogenic treatment.

Infusional fluorouracil, epirubicin, and cisplatin followed by weekly paclitaxel plus bevacizumab in locally advanced breast cancer with unfavorable prognostic features.

The objective of this study was to evaluate the clinical and biological activities of bevacizumab in combination with preoperative anthracyclines and taxane-based chemotherapy in locally advanced breast cancer selected for unfavorable prognostic features. Patients with cT2-4c, cN0-2, estrogen and progesterone receptors less than 10% of the cells or cT4d and any estrogen/progesterone receptors expression received four courses of ECF-chemotherapy (epirubicin, cisplatin, fluorouracil as continuous infusion) followed by three courses of weekly paclitaxel in combination with bevacizumab. Thirty patients were included in the study. An objective response, either complete or partial, was observed in 26 patients (87%; 95% confidence interval: 69-96%), stable disease was observed in two patients (7%), and two patients (7%) progressed. A pathological complete response was obtained in 10 patients (33%; 95% confidence interval: 17-53%). Side effects related to bevacizumab with grade >or=2 included headache and hypertension. A nonstatistical significant decrease in the median value of circulating endothelial cells was observed at surgery (3.0/microl vs. 5.7/microl, P=0.19). In conclusion, high rates of both clinical and pathological responses with anthracycline-containing chemotherapy followed by weekly paclitaxel plus bevacizumab were observed in locally advanced breast cancer with unfavorable prognostic features. A non-negligible rate of progressive disease was observed, suggesting careful monitoring of the patients. Further studies evaluating the potential benefit of bevacizumab in neoadjuvant treatment need to be tested.

Human acute leukemia cells injected in NOD/LtSz-scid/IL-2Rgamma null mice generate a faster and more efficient disease compared to other NOD/scid-related strains.

Transplantation of human acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL) primary cells and cell lines in different strains of immunodeficient mice has led to preclinical models extensively used to investigate acute leukemia stem cells, biology and drug sensitivity. We studied the engraftment kinetics of AML and ALL cell lines and primary cells in 3 strains of NOD.CB17-Prkdc(scid) (NOD/scid, NS)-related mice (NOD.Cg-Prkdc(scid)B2m(tm1Unc)/J, abbreviated NOD/scid/beta2 null, NSB; and NOD.Cg-Prkdc(scid)Il2rg(tm1Wjll)/SzJ, abbreviated NOD/scid/IL-2Rgamma null, NSG). The engraftment of human malignant cells was investigated by means of clinicopathological criteria, flow cytometry, PCR and immunohistochemistry. In NSG mice, we observed a significantly faster development of leukemia-related symptoms and a higher percentage of leukemia cells in the blood, in the marrow and in the spleen. The leukemia-related angiogenic switch (measured as the number of circulating endothelial cells and progenitors) was faster in NSG compared to NS and NSB mice. These models will be instrumental to studies on leukemia-initiating stem cells, leukemia biology, preclinical treatment studies, and to obtain patient-specific preclinical models to design and investigate patient-tailored therapies.

Molecular and cellular biomarkers for angiogenesis in clinical oncology.

Medical oncologists are increasingly using anti-angiogenic drugs, but identifying the best-suited drug and the optimal dosage and schedule for treatment of patients remain challenging issues. Circulating endothelial cells (CECs) and circulating endothelial progenitors (CEPs) are modulated in a variety of diseases including cancer, and are promising surrogate biomarkers in oncology. Molecular surrogate markers, on the other hand, are more scanty at the present time, because the identification of truly endothelial cell-restricted genes and/or antigens is complex. Here, we discuss the biological and technical facets of the search and validation of new biomarkers for angiogenesis.