Clonal Megakaryocyte Dysplasia with Isolated Thrombocytosis Is a Distinct Myeloproliferative Neoplasm Phenotype.

INTRODUCTION: About 15% of people with a myeloproliferative neoplasm (MPN) are identified as MPN, unclassifiable using the 2016 WHO classification. METHODS: We tested whether persons with platelet concentration ≥450 × 10E+9/L, bone marrow megakaryocyte morphology typical of prefibrotic/early myelofibrosis (pre-MF), and no minor criteria of pre-MF should be classified as a distinct MPN subtype, clonal megakaryocyte dysplasia with isolated thrombocytosis (CMD-IT). RESULTS: 139 subjects meet these criteria who we compared with primary myelofibrosis (PMF) including 402 with pre-MF and 521 with overt myelofibrosis. CMD-IT subjects were more likely female and younger. They had lower frequencies of JAK2V617F compared with persons with PMF (55% vs. 70%; p < 0.001) and higher frequencies of CALR mutations (37% vs. 17%; p < 0.001). They also had lower frequency of variations associated with JAK2V617F susceptibility, JAK2 46/1 (35% vs. 47%; p = 0.021), and VEGFA rs3025039 (12% vs. 17%; p = 0.030). Subjects with CMD-IT had lower incidences of thrombotic events compared with those with pre-MF (9.7% vs. 26%; p < 0.001) and longer survival (median, not reached vs. 23 years; HR = 0.34 (0.10, 0.30); p < 0.001). CONCLUSION: Our data indicate CMD-IT is a distinct MPN subtype and should be included in the classification of myeloid neoplasms.

Hematological disorders after salvage PARPi treatment for ovarian cancer: Cytogenetic and molecular defects and clinical outcomes.

Inhibitors of poly(ADP-ribose) polymerase (PARPi) are increasingly employed as salvage therapy in epithelial ovarian cancer (EOC), but cytotoxic drug exposure along with PARP inhibition may favor development of hematological disorders. In our study, of 182 women with EOC treated with PARPi, 16 (8.7%) developed therapy-related myeloid neoplasms (t-MNs), with 12 cases of myelodysplasia and 4 of acute myeloid leukemia. All experienced persistent cytopenia after PARPi discontinuation. Seven patients had del(5q)/-5 and/or del(7q)/-7, nine had a complex karyotype and TP53 mutations, recently reported as risk factor for t-MNs in EOC post-PARPi, were found in 12 out of 13 tested patients. Four patients had a rapid and fatal outcome, one had stable disease, eleven underwent induction therapy, followed by allogeneic hematopoietic cell transplantation in seven. Three of these 11 patients experienced refractory disease, and 8 had complete remission. During a 6.8 months (range 2.3-49) median observation time, 3 out of 16 patients were alive, with one surviving patient free of both solid and hematological tumors. Ten patients died because of leukemia, two because of transplant-related events, one from heart failure. Five more patients experienced persistent cell blood count abnormalities following PARPi discontinuation, without reaching MDS diagnostic criteria. A customized Myelo-panel showed clonal hematopoiesis in all five patients. These findings confirm the actual risk of t-MNs in EOC patients after chemotherapy and prolonged PARPi therapy. The management of these patients is complex and outcomes are extremely poor. Careful diagnostic procedures are strongly recommended whenever unusual cytopenias develop in patients receiving PARPi therapy.

Clonal Megakaryocyte Dysplasia with Normal Blood Values Is a Distinct Myeloproliferative Neoplasm.

INTRODUCTION: In 1991, we reported 18 persons with a clinical-pathologic entity and termed atypical myeloproliferative disorder because they did not meet the contemporary diagnostic criteria for a myeloproliferative neoplasm. We sought to gain further knowledge on this disease entity. METHODS: This retrospective cohort study included consecutive subjects registered in the database of the Center for the Study of Myelofibrosis in Pavia, Italy, from 1998 to 2020 (June), and diagnosed with atypical myeloproliferative disorder according to our adjudicated criteria. We studied clinical, histological, cytogenetic, and molecular covariates and risks of thrombosis, disease progression, and death. Data were compared with those of concurrent subjects with prefibrotic myelofibrosis. RESULTS: Fifteen new subjects with atypical myeloproliferative disorder were identified. Seven were male. Median age was 50 years (IQR, 41-54 years). Thirteen were diagnosed with a synchronous symptomatic or incidentally detected thrombotic event. The bone marrow showed megakaryocyte hyperplasia with dysplasia. JAK2V617F was present in 10 subjects and CALR mutation in one. No other somatic mutations were identified in next generation sequencing. After a median follow-up of 101 months (IQR, 40-160 months), no subject had disease progression or blast transformation. Incidence of post-diagnosis or recurrent thrombosis was 3.9 events (95% confidence interval, 3.5-4.0) and 5.0 events (4.6-5.6) per 100 person-years. Features of subjects with atypical myeloproliferative disorder differed markedly from those of 546 subjects with prefibrotic myelofibrosis. CONCLUSION: Our data indicate that these 15 persons have a distinct myeloproliferative neoplasm. We propose naming this new disorder clonal megakaryocyte dysplasia with normal blood values.

Clinical presentation, diagnosis and management of therapy-related hematological disorders in women with epithelial ovarian cancer treated with chemotherapy and poly-ADP-ribose polymerase inhibitors: A single-center experience.

We investigated the occurrence and management of therapy-related hematological disorders (tr-HDs) in women with epithelial ovarian cancer (EOC) exposed to poly-ADP-ribose polymerase inhibitors (PARPi), after previous chemotherapy. We analyzed 130 consecutive EOC patients treated with PARPi at the European Institute of Oncology, Milan. In line with the literature, overall survival of the entire population was 37% at 5.5 years (89% were advanced stages). Cell blood counts were collected prior to start PARPi, at each new cycle and at monthly intervals. Patients displaying persistent and/or marked hematological abnormalities underwent bone marrow evaluation, with cytogenetic and molecular analysis. Nine patients (6,9%) developed tr-HDs, after a median 22.8 months of PARPi exposure. Two patients died early and could not be treated. Two patients have no indication for active treatment and are presently under close hematological monitoring. Five patients underwent chemotherapy followed, in three cases, by allogeneic hematopoietic transplantation: three patients are in complete remission of their hematological and gynecological malignancies at 13, 19, and 25 months; the remaining two patients died due to progression of their hematological disease. We show the potential risk of hematological disorders in EOC patients treated with chemotherapy and prolonged PARPi therapy. In our series, tr-HDs incidence was higher compared to recent reports in large series. Our observations suggest careful monitoring in order to conclusively define, on large series and prolonged follow-up, the actual risk of tr-HDs in patients under PARPi. Notably, prompt diagnosis of hematological abnormalities and appropriate management allow achievement of remission from severe hematological complications, at least in most patients.

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.

Circulating tumor DNA in patients with locally advanced rectal cancer treated with multimodal treatment.

Background: The management of locally advanced rectal cancer (LARC) relies on a multimodal approach. Neither instrumental work-up nor molecular biomarkers are currently available to identify a risk-adapted strategy. Objectives: We aim to investigate the role of circulating tumor DNA (ctDNA) and its clearance at different timepoints during chemo-radiotherapy (CRT) and correlate them with clinical outcomes. Design: Between November 2014 and November 2019, we conducted a monocentric prospective observational study enrolling consecutive patients with LARC managed with neoadjuvant standard CRT (capecitabine and concomitant pelvic long-course radiotherapy), followed by consolidation capecitabine in selected cases and surgery. Methods: Blood samples for ctDNA were obtained at pre-planned timepoints. We evaluated the correlation of baseline variant allele frequency (VAF) with pathologic complete response (pCR) down-staging, node regression (pN0), event-free survival (EFS), and overall survival (OS). Results: Among 112 screened patients, 61 were enrolled. In all, 38 (62%) had a positive ctDNA at baseline with VAF > 0 and 23 had negative ctDNA (VAF = 0). Among patients with negative ctDNA, 30% had a complete response, while only 13% of positive ctDNA patients had pCR [odds ratio (OR) 0.35 (95% confidence interval (CI): 0.10-1.26), p = 0.11]. Similarly, 96% and 74% of pN0 were observed among negative and positive ctDNA patients, respectively [OR 0.13 (95% CI: 0.02-1.07), p = 0.058]. The presence of a baseline VAF > 0 was associated with a trend toward a lower EFS compared with VAF = 0 patients [hazard ratio (HR) = 2.30, 95% CI: 0.63-8.36, p = 0.21]. Within the limitations of small sample size, no difference in OS was observed according to the baseline ctDNA status (HR = 1.18, 95% CI: 0.35-4.06, p = 0.79). Conclusion: Within the limitations of a reduced number of patients, patients with baseline negative ctDNA seem to show a higher probability of pN0 status and a trend toward improved EFS. Prospective translational studies are required to define the role of ctDNA analysis in the multimodal treatment of LARC.

Emergency Lung Transplantation after COVID-19: Immunopathological Insights on Two Affected Patients.

We herein characterize the immunopathological features of two Italian COVID-19 patients who underwent bilateral lung transplantation (bLTx). Removed lungs underwent histopathological evaluation. Gene expression profiling (GEP) for immune-related signatures was performed on lung specimens and SARS-CoV-2-stimulated peripheral blood mononuclear cells (PBMCs). Cytokine levels were measured on lungs, bronchoalveolar lavage fluids and in culture supernatants. Pathological assessment showed extensive lung damage with the pattern of proliferative to fibrotic phases, with diffuse alveolar damage mimicking usual interstitial pneumonia (UIP). Lungs' GEP revealed overexpression of pathogen recognition receptors, effector cytokines and chemokines, immune activation receptors and of the inflammasome components. Multiplex cytokine analysis confirmed a proinflammatory state, with high levels of monocyte/macrophage chemotactic and activating factors and of IL-6 and TNF-α. A similar profile was observed in SARS-CoV-2-stimulated PBMCs collected 7 days after transplant. The pattern of tissue damage observed in the lungs suggests that this may represent the output of protracted disease, resembling a diffuse UIP-like picture. The molecular immune profiling supports the paradigm of a persistent proinflammatory state and sustained humoral immunity, conditions that are maintained despite the iatrogenic immunosuppression.

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.

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

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.

Construction of a natural panel of 11p11.2 deletions and further delineation of the critical region involved in Potocki-Shaffer syndrome.

Potocki-Shaffer syndrome (PSS) is a contiguous gene deletion syndrome that results from haploinsufficiency of at least two genes within the short arm of chromosome 11[del(11)(p11.2p12)]. The clinical features of PSS can include developmental delay, mental retardation, multiple exostoses, parietal foramina, enlarged anterior fontanel, minor craniofacial anomalies, ophthalmologic anomalies, and genital abnormalities in males. We constructed a natural panel of 11p11.2-p13 deletions using cell lines from 10 affected individuals, fluorescence in situ hybridization (FISH), microsatellite analyses, and array-based comparative genomic hybridization (array CGH). We then compared the deletion sizes and clinical features between affected individuals. The full spectrum of PSS manifests when deletions are at least 2.1 Mb in size, spanning from D11S1393 to D11S1385/D11S1319 (44.6-46.7 Mb from the 11p terminus) and encompassing EXT2, responsible for multiple exostoses, and ALX4, causing parietal foramina. Yet one subject with parietal foramina whose deletion does not include ALX4 indicates that ALX4 in this subject may be rendered functionally haploinsufficient by a position effect. Based on comparative deletion mapping of eight individuals with the full PSS syndrome including mental retardation and two PSS families with no mental retardation, at least one gene related to mental retardation is likely located between D11S554 and D11S1385/D11S1319, 45.6-46.7 Mb from the 11p terminus.

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.

Inverted duplications: how many of them are mosaic?

The best-known situation indissolubly linked to mosaicism is the uniparental disomy where a trisomic or monosomic zygote develops at least one cell line with 46 chromosomes. The mosaicism normal/abnormal cell lines may remain confined to placenta or persist in the embryo. Here, we describe a second situation that might also be indissolubly linked to a mosaic condition or at least to a confined placental mosaicism. We analysed the case of a mosaicism del(8p)/inv dup(8p) found in prenatal diagnosis. We had already demonstrated that the first product of the abnormal meiotic recombination at the basis of the inv dup rearrangements is a dicentric chromosome. Its breakage leads to the formation of a deleted and an inv dup chromosome. Although we had previously assumed that the dicentric underwent a breakage at meiosis II so that the zygote inherited the inv dup chromosome, our findings and those of others indeed indicate that the dicentric may be inherited in the zygote and that it might persist as such in early postzygotic stages, then undergoing different breakages in different cells leading to different abnormal chromosomes, either deleted or duplicated. Selection versus the most viable cell line(s) results either in a confined placental mosaicism with the inv dup cell line as the only one present in the embryo or in children with both the deleted and the inv dup cell lines. Phenotype/karyotype relationships in inv dup rearrangements must also take into account the influence of the other abnormal cell line during embryogenesis.

Oral, facial, digital, vertebral anomalies with psychomotor delay: a mild form of OFD type Gabrielli?

A girl with oral, facial, and digital anomalies presented at birth with a large cleft palate filled by a nasopharyngeal mass and was found later to have several vertebral anomalies and mental retardation. A similar phenotype has been previously reported in a sporadic male patient [Gabrielli et al., 1994: Am J Med Genet 53:290-293], suggesting a new variant form of oral-facial-digital syndrome.

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.

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.

Spontaneous cell fusion of acute leukemia cells and macrophages observed in cells with leukemic potential.

Cell fusion plays a well-recognized physiological role during development, while its function during progression is still unclear. Here, we show that acute myeloid leukemia (AML) cells spontaneously fused with murine host cells in vivo. AML cells fused in most cases with mouse macrophages. Other targets of AML cell fusion were dendritic and endothelial cells. Cytogenetic and molecular analysis revealed that successive recipients conserved detectable amounts of parental DNA. Moreover, in a mouse AML1-ETO model where female AML1-ETO-leukemic cells, expressing CD45.2, were injected in congenic CD45.1 male mice AML cells, we found hybrid cells expressing both allelic types of CD45 and XXY set of sexual chromosomes. More importantly, the fusion protein AML1-ETO was transferred in the hybrid cells. When sorted hybrid cells were reinjected in a secondary recipient, they gave rise to leukemia with 100% penetrance and similar time of onset of leukemic cells. Our data indicate that in vivo fusion of cancer cells with host cells may be a mechanism of gene transfer for cancer dissemination and suggest that fused cells may be used to identify still unrecognized leukemogenic genes that are conserved in hybrid cells and able to perpetuate leukemia in vivo.

The white adipose tissue used in lipotransfer procedures is a rich reservoir of CD34+ progenitors able to promote cancer progression.

Previous studies have suggested a "catalytic role" in neoplastic angiogenesis and cancer progression for bone marrow-derived endothelial progenitor cells (EPC). However, preclinical and clinical studies have shown that the quantitative role of marrow-derived EPCs in cancer vascularization is extremely variable. We have found that human and murine white adipose tissue (WAT) is a very rich reservoir of CD45-CD34(+) EPCs with endothelial differentiation potential, containing a mean of 263 times more CD45-CD34(+) cells/mL than bone marrow. Compared with marrow-derived CD34(+) cells mobilized in blood by granulocyte colony-stimulating factor, purified WAT-CD34(+) cells expressed similar levels of stemness-related genes, significantly increased levels of angiogenesis-related genes, and increased levels of FAP-α, a crucial suppressor of antitumor immunity. In vitro, WAT-CD34(+) cells generated mature endothelial cells and capillary tubes as efficiently as mature mesenchymal cells. The coinjection of human WAT-CD34(+) cells from lipotransfer procedures contributed to tumor vascularization and significantly increased tumor growth and metastases in several orthotopic models of human breast cancer in immunodeficient mice. Endothelial cells derived from human WAT-CD34(+) cells lined the lumen of cancer vessels. These data indicate that CD34(+) WAT cells can promote cancer progression and metastases. Our results highlight the importance of gaining a better understanding of the role of different WAT-derived cells used in lipotransfer for breast reconstruction in patients with breast cancer.

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.