Tie2-expressing Monocytes Research Articles

Genetic Engineering of Hematopoietic Progenitor Stem Cells for Targeted IFN-α Immunotherapy Reprogramming the Solid Tumor Microenvironment: A First-in-Man Study in Glioblastoma Multiforme (NCT03866109)

Background and methods . TEM-GBM is a Phase 1/2a dose-escalating non-randomized open label study, involving a single intravenous injection of Temferon. Temferon is constituted by autologous CD34+ HSPCs genetically modified with a lentiviral vector encoding for human interferon-a2 and has been designed to deliver IFNa in the tumor microenvironment (TME) in a targeted manner via Tie-2 expressing monocytes (TEMs). The patient population is newly diagnosed GBM patients with unmethylated MGMT gene promoter. The study aims to evaluate the short-term (up to 90 Days) and long-term (up to 2 years) tolerability and safety of five escalating doses of Temferon in up to 27 glioblastoma patients. The secondary objective is to evaluate biological activity and efficacy when used following SOC first line therapeutic approaches. Autologous CD34+ HSPC are mobilized with lenograstim and plerixafor, collected by apheresis, purified and ex vivo modified with a lentiviral vector. So far, up to 3 million Temferon cells/kg have been co-administered with a fixed dose of non-manipulated CD34+ supporter cells following a sub-myeloablative conditioning regimen (Thiotepa + BCNU or Busulfan or Busulfan alone). Results. As of 30th June 2023, twenty-one patients have been enrolled across 7 cohorts evaluating 4 incremental doses (0.5-3.0x10 6/kg) of Temferon. To date, no DLTs have been identified. Median Overall Survival after 1st surgery is 17 months (5-40 months). In all patients, rapid engraftment of gene modified progenitors and fast recovery from sub-myeloablative conditioning regimens have been observed (median engraftment across all the cohorts: Neutrophils D+12, Platelets D+13,5 following Temferon infusion). The percentage of transduced cells found in the BM obtained for the highest dose reached 50% at 1 month and persisted at detectable level in the long-term. Very low median concentrations of IFNa were detected in the plasma, indicating tight regulation of vector expression. Notably, the concentration of IFNa in the CSF increased concomitantly with disease progression suggesting active recruitment of TEMs into the tumor and subsequent release of IFNa. 57% of the treated patients underwent a 2nd-line treatment (either pharmacological or surgical) with an interim survival rate at 2-years of 28% (5 of 18 patients; 3 patients excluded as follow-up is below 12 months), which is higher than what is reported in literature (15%). One out of the surviving patients was enrolled in a long-term follow-up study and survived up to 3 years after surgery without any 2nd-line therapy. Genetically engineered cells were detected within the tumor lesion at levels >3% in 3/6 patients at second surgery. Single cell RNA seq analysis unveiled reprogramming of the myeloid TME, with an increase in pro-inflammatory (M1-like) and a decrease in hypoxic (M2-like) macrophages following Temferon exposure. Of note, this population shift was particularly evident when comparing a stable with a progressive tumor lesion biopsied contemporaneously in one patient, reproducing preclinical findings from a GBM mouse model (PMID: 35857642). Analysis of the T cell compartment highlighted an overall increase of CD8+ T cells (mainly effector T cell subsets) and a decrease in CD4+ T cells in Temferon patients. By mapping published signatures of antitumor neoantigen-reactive T cells (NeoTCR; PMID: 35113651) onto the GBM T cell landscape and integrating this data with clonal frequency metrics from concurrent scTCRseq data, we observed an approximately 3-fold increase of predicted tumor-reactive CD8+ T cells bearing expanded clonotypes (>1% within each patient) in Temferon vs. control patients. Strong up-regulation of IFNa and inflammatory responses in most of the clusters from myeloid and T cells, but also CD45- tumor and stromal cell compartments from Temferon patients suggested diffuse IFNa payload delivery into the GBM TME. Conclusion: These data show that Temferon is safe and biologically active at the tumor site and favors anti-tumor immunity. The results provide initial evidence of Temferon's potential to modulate the TME of GBM patients and to counteract disease progression and improve the survival of uMGMT GBM patients.

Expression of Tie2 (angiopoietin receptor) on the monocyte subpopulations from ischemic stroke patients: Histological and flowcytometric studies.

Different subpopulations of monocytes play roles in phagocytosis, inflammation, and angiogenic processes e.g., Tie2-expressing monocytes (TEMs). The brain is flooded with macrophages that are derived from monocytes within 3-7 days after a stroke. This study aimed to determine the expression level of Tie2 (an angiopoietin receptor) on monocytes and their subpopulations in ischemic stroke patients using the histological and immunohistological study of bone marrow biopsies and blood flow cytometry examination. Ischemic stroke patients within two days were selected. Participants in the control group were healthy volunteers of matched age and gender. Sample collection was performed within 24 to 48 hours after medical consultants confirmed the stroke diagnosis. An iliac crest bone marrow biopsy was obtained and fixed for histological and immunohistological staining with antiCD14 and antiCD68. Flow cytometry was used to determine the total monocyte population, monocyte subpopulations, and TEMs after staining with monoclonal antibodies to CD45, CD14, CD16, and Tie2. Post-stroke patients' bone marrow cells were hypercellular. There was an apparent increase in CD68 and CD14-positive cells. Ischemic stroke patients exhibited low percentages of nonclassical monocytes CD14lowCD16++, with an increase in intermediate monocytes CD14highCD16+. Moreover, ischemic stroke patients had significantly higher levels of TEMs than control group. The results of this study demonstrate dysregulation of angiogenesis in monocyte subsets in ischemic stroke patients, which could be used as an early diagnostic marker of neurovascular damage and may need angiogenic therapy or improved medications to prevent further damage of blood vessels.

Characterization of circulating immune cells and correlation with Tie2/Angiopoietins level in well differentiated neuroendocrine gastroenteropancreatic tumors: a cross-sectional analysis.

The immune environment represents a new, but little explored, tool for understanding neuroendocrine neoplasms (NENs) behavior. An immunosuppressed microenvironment is hypothesized to promote NENs progression. A missing profiling of circulating leukocyte and peripheral blood mononuclear cells (PBMCs) subpopulations would open new perspectives in the still limited diagnostic-therapeutic management of NENs. A cross-sectional case-control pilot study was performed recruiting 30 consecutive subjects: 15 patients naïve to treatment, with histologically proven gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) and 15 healthy controls, matched for age and sex. PBMCs subpopulations were studied by flow cytometry. Soluble Tie2 (sTie2), Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2) were evaluated by ELISA. Immune cell profiling revealed a significant lower CD3-CD56+ natural killer (NK) cell count in NETs vs controls (p = 0.04). NK subset analysis showed a reduced relative count of CD56+CD16+ NK cells (p =0.002) in NETs vs controls. Patients with NET showed a higher percentage of CD14+CD16++ non-classical monocytes (p = 0.01), and a lower percentage of CD14+CD16+ intermediate monocytes (p = 0.04). A decrease in percentage (p = 0.004) of CD4+ T-helper lymphocytes was found in NET patients. Evaluation of cellular and serum angiopoietin pathway mediators revealed in NET patients a higher relative count of Tie2-expressing monocytes (TEMs) (p < 0.001), and high levels of Ang-1 (p = 0.003) and Ang-2 (p = 0.002). Patients with GEP-NET presented an immunosuppressed environment characterized by a low count of cytotoxic NK cells, a high count of anti-inflammatory non-classical monocytes, and a low count of T-helper lymphocytes. Higher levels of TEMs and angiopoietins suggest a crosstalk between innate immunity and angiogenic pathways in NETs.

Role of Proangiogenic Tyrosine Kinase with Immunoglobulin and Endothelial Growth Factor Homology Domains 2 Expressing Monocytes in Chronic Lymphocytic Leukemia

Background: Globally, highest hematologic malignancy in prevalence is considered chronic lymphocytic leukemia (CLL). The expression of angiopoietin-2 (Ang2) and tyrosine kinase with immunoglobulin and endothelial growth factor homology domains (Tie1), two critical components of the Ang-Tie2 pro-angiogenic pathway, in CLL cells has been demonstrated. Objective: Clarification of Tie2-expressing monocytes’ (TEMs) involvement in the pathophysiology of CLL is the goal of this study. Patients and Methods: The study was case control, which was performed on 21 CLL patients; their age ranged from 46 to 71 with a mean of 58.2 ± 6.9, in addition to 21 age and sex matched healthy control subjects. Full medical histories, clinical examinations, and laboratory tests were conducted on all individuals. The percentage of TEMs in peripheral blood was determined by flow cytometry and their phenotypic characteristics defined as CD14+/CD16+/Tie-2+ cells. Results: Compared to the control group, there was a statistically significant increase in TEMs in the cases group. Among the cases group there was a statistical significant increase in LDH, uric acid, WBCs, reticulocyte, CD 38 β2 microglobulin and TEMS and statistical significant decrease in Hb with increase Binet stage. There was a statistical significant +ve correlation between TEMs and LDH, WBCs, reticulocytes, CD38 and β2 microglobulin. Also, there was a statistical significant negative correlation between TEMs and Hb and platelets count among the cases group. TEMs percentage had sensitivity, specificity and accuracy (100%) in diagnosis of leukemia at cut off > 20.95%. Conclusion: TEMs could be a part of CLL pathogenesis which can be a predictor of disease progression alongside with other prognostic indicators.

Prognostic Value of Tie2-Expressing Monocytes in Chronic Lymphocytic Leukemia Patients.

Simple SummaryTie2-expressing monocytes (TEM) characterized by the phenotype of CD14+CD16+Tie2+ are seen as the new immunosuppressive force in tumors. However, little is known about the role of circulating TEM in chronic lymphocytic leukemia (CLL) as opposed to their role in solid tumors. In the current study, we observed an increased percentage of TEMs in CLL patients. A greater than 14.82% proportion of TEM foretells an unfavorable prognosis. This threshold has predicted a shorter time from diagnosis to therapy, and worse overall survival. Despite these results, a multivariable Cox regression model performed in 104 CLL patients did not identify TEM as an independent predictor of survival. However, TEM, as an important element of the tumor-microenvironment, can be an important complement to other prognostic indicators.Tie2-expressing monocytes (TEMs) are associated with tumor progression and metastasis. This unique subset of monocytes has been identified as a potential prognostic marker in several solid tumors. However, TEMs remain poorly characterized in hematological cancers, including chronic lymphocytic leukemia (CLL). This study analyzed, for the first time, the clinical significance of TEM population in CLL patients. Flow cytometry analysis of TEMs (defined as CD14+CD16+Tie2+ cells) was performed at the time of diagnosis on peripheral blood mononuclear cells from 104 untreated CLL patients. Our results revealed an expansion of circulating TEM in CLL patients. These monocytes express high levels of VEGF and suppressive IL-10. A high percentage of TEM was associated closely with unfavorable prognostic markers (ZAP-70, CD38, 17p and 11q deletion, and IGHV mutational status). Moreover, increased percentages of circulating TEMs were significantly higher in patients not responding to the first-line therapy as compared to responding patients, suggesting its potential predictive value. High TEM percentage was also correlated with shorter overall survival (OS) and shorter time to treatment (TTT). Importantly, based on multivariate Cox regression analysis, TEM percentage was an independent predictor for TTT. Thus, we can suggest the adverse role of TEMs in CLL.

Phase II randomized, double-blind study of mFOLFIRINOX plus ramucirumab versus mFOLFIRINOX plus placebo in advanced pancreatic cancer patients (HCRN GI14-198).

413 Background: Vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR)-mediated signaling and angiogenesis contribute to the pathogenesis and progression of pancreatic adenocarcinoma (PCA).VEGF is expressed in all PCA tumors. VEGF-A/VEGFR-2 signaling plays an important role in inducing invasion and migration of PCA cells. The pVEGFR-2 is significantly associated with invasion of the anterior capsule of pancreas and arteries. In preclinical studies, the anti-tumor activity of fluoropyrimidines, but not that of gemcitabine, caused the release of bone marrow derived circulating endothelial progenitor cells (CEPs) and Tie-2 expressing monocytes (TEMs) as well as the induction of pro-angiogenic growth factors. Methods: This phase II randomized, multi-center, and double-blinded trial was designed to compare the efficacy and safety of mFOLFIRINOX/ramucirumab (Arm A) versus mFOLFIRINOX/ placebo (Arm B) as front-line therapy in recurrent or metastatic PCA patients. The primary endpoint was progression free survival (PFS) at 9 months, and the secondary endpoints included overall survival (OS) and response rate. Results: A total of 86 subjects were enrolled, 82 were eligible (42 in Arm A v. 40 in Arm B). The mean age of the subjects in the two arms were comparable (61.7 v. 63.0, respectively); 43 male, 69 Caucasian. On the univariate analysis, there was no difference in distribution between the 2 arms for age, gender, race and ethnicity. The median PFS was 5.6 in Arm A compared to 6.7 months in Arm B (one-sided log-rank, p = 0.322). At 9 months, the progression free rates were 25.1% v. 35% for Arms A and B, respectively. The mFOLFIRINOX/ramucirumab combination was well tolerated. Patients in Arm A reported a slightly higher number of adverse events (AEs) encounters, most commonly diarrhea (29 vs 28), fatigue (25 v. 25), vomiting (24 v. 14), weight loss (23 v. 17), and abdominal pain (20 v. 15). Arm A had more SAEs than Arm B (43 v. 25), with sepsis most commonly reported in both arms (3 in each), vomiting (3 v. 2), diarrhea (3 v.1) and duodenal obstruction (3 v. 0). Arm B had a slightly higher response rate (22.58%) compared to Arm A (17.65%) that was not statistically significant. The median OS in Arm A was 10.3 compared to 9.7 months for Arm B (one-sided log-rank, p = 0.094). Conclusions: In this randomized phase 2 study, the addition of ramucirumab to mFOLFIRINOX did not improve PFS, response rate, or OS as initial therapy for metastatic pancreatic cancer. FOLFIRINOX/Ramucirumab combination was well tolerated in the treatment of PCA. Clinical trial information: NCT02581215.

Tie-2-expressing monocytes in hepatitis C virus-related hepatocellular carcinoma

Background Angiogenesis is a critical step in the development and progression of hepatocellular carcinoma (HCC). Tie-2-expressing monocytes (TEMs) with proangiogenic activity are recruited to the tumor site where they stimulate tumor angiogenesis. Objective This study aimed to assess the role of TEMs in diagnosis of hepatitis C virus (HCV)-related HCC. Patients and methods The study was conducted on 50 patients diagnosed with HCC and HCV. Patients were categorized into two groups: one included patients with HCC (n=25) and the other included HCV-infected patients (n=25). Moreover, 25 age-matched and sex-matched healthy individuals were recruited as a control group. The frequency of TEMs, as defined as CD14+CD16+Tie-2+ cells, in the peripheral blood was determined by flow cytometry. Results The frequency of TEMs in peripheral blood (PB) monocytes was significantly higher in HCC group (53.1±18.2%) than in patients with HCV (27.3±13.9%) and controls (8.4±3.9%). The percentage of TEMs correlates with advanced Child-Pugh stage in patients with HCC and HCV infection (P&lt;0.01). Upon performing receiver operating characteristics curve analysis, a cutoff point of 33% for TEMs was able to differentiate patients with HCC from HCV-infected patients. Regarding differentiating patients with HCC from healthy participants, the cutoff value of 33.8% yielded 88% sensitivity and 100% specificity. The diagnostic performance of combination of TEMs and α-fetoprotein was also assessed, with 98% sensitivity and 100% specificity. Conclusion Percentage of TEMs in PB monocytes may be applied as a complementary biomarker for identifying HCV-related HCC along with α-fetoprotein. Inhibiting the proangiogenic functions of TEMs may represent a promising strategy to improve the efficacy of current treatments for HCC.

Tie2-expressing monocytes as a novel angiogenesis-related cellular biomarker for non-small cell lung cancer.

To investigate the clinical value of Tie2-expressing monocytes (TEMs) in the early diagnosis of lung cancer and assess its correlation with angiogenesis, a total of 184 patients with non-small cell lung cancer (NSCLC), 101 patients with benign pulmonary disease (BPD), and 77 healthy controls were enrolled in our study. The distribution of TEMs in lung tissue was determined by immunofluorescence staining. Lung microvascular density was assessed by immunohistochemical staining. Receiver-operating characteristic (ROC) curve analysis was performed to assess the diagnostic value of TEM frequency. Patients with NSCLC were followed up for 26 months. We found that the TEM frequency in peripheral blood monocytes of patients with NSCLC was significantly greater than that in patients with BPD and healthy controls. TEM frequency showed a correlation with NSCLC recurrence. The majority of TEMs in tumor tissues were localized around blood vessels; tumoral TEM frequency showed a positive correlation with microvascular density. High percentage of TEMs in the peripheral blood was associated with poor overall survival. ROC curve analysis revealed the potential diagnostic value of circulating TEM frequency in NSCLC. Thus, we believe that TEM frequency is related to angiogenesis in tumor tissues and may serve as a diagnostic marker for NSCLC.

Circulating Tie2-Expressing Monocytes: A Potential Biomarker for Cervical Cancer.

BackgroundTyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 (Tie2)-expressing monocytes (TEMs) are a highly proangiogenic subset of myeloid cells, which are characterized by expressing the angiopoietin receptor Tie2 with pro-tumor activity.PurposeThe present study aimed to determine the clinical value of circulating TEMs (cTEMs) for cervical cancer.Patients and MethodsPeripheral blood mononuclear cells (PBMCs) were obtained from 7 healthy volunteers, 17 uterine fibroid patients, 24 cervical intraepithelial neoplasia (CIN) II patients, 31 CIN III patients and 99 patients with cervical cancer. The cTEMs were evaluated by the ratio of Tie2+ CD14+ cells to all CD14+ monocytes in the PBMCs through flow cytometry. The diagnostic value of cTEM was assessed by receiver operating characteristic (ROC) curves and the correlation between cTEM and clinicopathological characters in cervical cancer patients was analyzed.ResultsThe proportion of cTEMs was gradually increasing from healthy volunteers to patients with non-invasive lesions, then to cervical cancer patients. The area under the ROC curve was 0.913 when the level of cTEMs was used to distinguish cervical cancer from all the other women ranging from healthy volunteers to CIN III patients. In cervical cancer, an increased cTEM fraction was significantly correlated with advanced tumor stage, larger tumor size, lymph node metastasis (LNM), deep stromal infiltration, parametrial involvement and lymph-vascular space invasion and was an independent risk factor for LNM.ConclusionThe cTEM proportion might be a promising biomarker for the malignant transformation of cervical lesions and the progression of cervical cancer.

Recipient Hepatic Tumor-Associated Immunologic Infiltrates Predict Outcomes After Liver Transplantation for Hepatocellular Carcinoma.

BackgroundTransplantation of the liver entails a state of altered recipient immunologic competence. There are only scarce data concerning the impact of host immunologic factors on the outcome of liver transplant recipients in the context of hepatocellular carcinoma (HCC).Material/MethodsOur study focused on evaluating the presence of tumor necrosis and frequency levels of angiopoietins and monocytes/macrophages subtypes in the host liver prior to liver transplantation (LTX) and their association with recurrence, graft rejection, survival, and clinical prognosis after LTX. Formation of tumor necrosis and tissue densities of angiopoietins and cellular immunologic infiltrates – CD68+ and CD163+ macrophages (TAMs) and TIE2-expressing monocytes (TEMs) – were quantified in recipient HCC specimens. The densities were then matched with clinicopathologic variables and patient survival after LTX (n=88). Some patients were treated prior to LTX by neoadjuvant transarterial chemoembolization (TACE, n=55).ResultsRecipient hepatic infiltration with TEMs and CD68+ TAMs was associated with decreased 1-, 3-, and 5-year survival, as well as metastatic and recurrent HCC after LTX (all p<0.05). TEMs and infiltrating monocytes/macrophages were associated with angiopoietin expression, metastatic, and recurrent HCC (all p<0.05). Furthermore, hepatic angiopoietin-2 expression was associated with graft rejection after LTX (p<0.05). After TACE and LTX, formation of tumor necrosis was associated with an increased presence of monocytes/macrophages and a reduced incidence of recurrent HCC in the graft (all p<0.05).ConclusionsInfiltrating monocytes/macrophages subsets and related angiopoietin axis are associated with worse survival, tumor recurrence, and clinical outcome after LTX for HCC.

Angiogenic inflammation and formation of necrosis in the tumor microenvironment influence patient survival after radical surgery for de novo hepatocellular carcinoma in non-cirrhosis

BackgroundTumor escape mechanisms mediated in the tumor microenvironment can significantly reduce the capacity of the anti-tumor function of the immune system. TIE2-expressing monocytes (TEMs), related angiopoietins, and tumor necrosis are considered to have a key role in this process. We aimed to investigate the abundance and clinical significance of these biomarkers in hepatocellular carcinoma (HCC).MethodsIn this retrospective study, 58 HCC patients received surgery with a curative intent. The abundance of TEMs, angiopoietin-1 and -2 were detected in tumor specimens of the HCC patients (n = 58), and together with the occurrence of histologic tumor necrosis, were associated with established clinicopathological characteristics and survival.ResultsPatients with HCC characterized by necrosis and TEMs revealed reduced both overall survival and recurrence-free survival (all p < 0.05). Angiopoietins and TEMs were associated with metastatic and recurrent HCC. Furthermore, the formation of histologic tumor necrosis was associated with advanced tumor stage and density of TEMs (all p < 0.05).ConclusionsHistologic tumor necrosis, TEMs, and related angiopoietins were associated with multiple HCC parameters and patient survival. The tumor necrosis–TEM–angiopoietin axis may offer a novel diagnostic modality to predict patient outcome after surgery for HCC.

Role of Tie2, CD14, Angiopoietin as Angiogenetic Markers in Hepatocellular Carcinoma Complicating Hepatitis C Virus Infection

Background Identifying biomarkers for early detection of hepatocellular carcinoma (HCC) remains quite challenging. In this study we aimed to estimate the number of TIE2-expressing monocytes (TEMs) cells, which display pro-tumoral activities and are defined as CD14+, TIE2+, and angiopoietin-2; and its potential use as a possible diagnostic marker in HCC patients complicating HCV induced cirrhosis. Methods Current study was conducted on 112 patients. They were divided into two groups: Group I (78 patients) with HCC complicating HCV induced cirrhosis; and group II chronic hepatitis C patients (34 patients). Both groups were compared to (age and sex-matched) healthy persons as group III (38 persons). Result The number of the circulating TEMs: CD14+ and TIE2+ monocytes were significantly higher in the peripheral blood of HCC patients than HCV LC patients and healthy controls, sensitivity and specificity for HCC diagnosis were respectively: CD14 (89.7%, 83.3%), TIE 2 (76.9%, 83.3%), and Ang-2 (76.9%, 66.7%). Moreover, analysis of the P-value and the odd’s ratio showed that CD14 has the highest predictive value for HCC. Conclusion Our results suggest that TEMs and Ang-2can be used as diagnostic markers for HCC, especially among the high-risk group of patients.

Sorafenib in Hepatopulmonary Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial.

The tyrosine kinase inhibitor sorafenib improves hepatopulmonary syndrome (HPS) in an experimental model. However, the efficacy and adverse effect profile in patients with HPS are unknown. We aimed to determine the effect of sorafenib on the alveolar-arterial oxygen gradient (AaPO2 ) at 3months in patients with HPS. We performed a randomized, double-blind, placebo-controlled parallel trial of sorafenib in patients with HPS at 7centers. A total of 28 patients with HPS were randomized to sorafenib 400mg by mouth daily or a matching placebo in a 1:1 ratio. We found no statistically significant difference in the median change in AaPO2 from baseline to 12weeks between the patients allocated to sorafenib (4.5mm Hg; IQR, -3.8 to 7.0mm Hg) and those allocated to placebo (-2.4mm Hg; IQR, -4.8 to 8.2mm Hg; P=0.70). There was also no difference between the groups in terms of degree of intrapulmonary shunting by contrast echocardiography. Sorafenib significantly reduced circulating levels of angiogenic markers, including vascular endothelial growth factor receptors (P<0.01) and TIE2-expressing M2 monocytes (P=0.03), but it reduced the mental component scores of the Short Form 36 (P=0.04), indicating a worse quality of life. In conclusion, sorafenib did not change the AaPO2 or other disease markers at 3months in patients with HPS. Alternative antiangiogenic therapies or treatments targeting other pathways should be investigated.

PDE5 Inhibition Stimulates Tie2-Expressing Monocytes and Angiopoietin-1 Restoring Angiogenic Homeostasis in Diabetes.

Vascular dysfunction is a common feature in end-organ complications of type 2 diabetes mellitus (T2DM). The endothelium-specific receptor tyrosine kinase Tie2 and its ligand, angiopoietin-1 (Ang1), participate in the processes of vessel repair, renewal, and maturation. However, their dysregulation in T2DM has seldom been investigated. To examine the relationship between angiogenic Tie2-expressing monocytes (TEMs) and Ang1, and their pharmacological modulation by the phosphodiesterase type 5 inhibitor (PDE5i) sildenafil, in T2DM and in db/db mouse model. Randomized, double-blind, placebo-controlled study. db/db male mice were randomly assigned to receive 8 weeks of sildenafil or vehicle. Diabetic men were randomly assigned to receive 4 weeks of sildenafil or placebo. Peripheral blood cells were investigated by flow cytometry to quantify inflammatory myeloid CD11b+ Gr1+ cells and proangiogenic TEMs in mice and classical CD14++CD16neg monocytes and proangiogenic TEMs in humans at baseline and after treatment. In vitro human tube formation assay was used to test serum angiogenic potential. We show that TEMs and Ang1 are defective in mouse and human models of diabetes and are normalized by PDE5i treatment. Serum angiogenic properties are impaired in diabetes because they do not support the in vitro formation of capillary-like structures, but they are reestablished by in vivo PDE5i treatment. Restoring a more physiological Tie2-Ang1 axis with sildenafil reestablishes serum angiogenic properties in diabetes, promoting angiogenic homeostasis.

Circulating angiogenic cell response to sprint interval and continuous exercise.

Although commonly understood as immune cells, certain T lymphocyte and monocyte subsets have angiogenic potential, contributing to blood vessel growth and repair. These cells are highly exercise responsive and may contribute to the cardiovascular benefits seen with exercise. To compare the effects of a single bout of continuous (CONTEX) and sprint interval exercise (SPRINT) on circulating angiogenic cells (CAC) in healthy recreationally active adults. Twelve participants (aged 29 ± 2 years, BMI 25.5 ± 0.9kgm- 2, [Formula: see text]peak 44.3 ± 1.8mlkg- 1min- 1; mean ± SEM) participated in the study. Participants completed a 45-min bout of CONTEX at 70% peak oxygen uptake and 6 × 20 s sprints on a cycle ergometer, in a counterbalanced design. Blood was sampled pre-, post-, 2h and 24h post-exercise for quantification of CAC subsets by whole blood flow cytometric analysis. Angiogenic T lymphocytes (TANG) and angiogenic Tie2-expressing monocytes (TEM) were identified by the expression of CD31 and Tie2, respectively. Circulating (cellsµL- 1) CD3+CD31+ TANG increased immediately post-exercise in both trials (p < 0.05), with a significantly greater increase (p < 0.05) following SPRINT (+ 57%) compared to CONTEX (+ 14%). Exercise increased (p < 0.05) the expression of the chemokine receptor CXCR4 on TANG at 24h. Tie2-expressing classical (CD14++CD16-), intermediate (CD14++CD16+) and non-classical (CD14+CD16++) monocytes and circulating CD34+CD45dim progenitor cells were higher post-exercise in SPRINT, but unchanged in CONTEX. All post-exercise increases in SPRINT were back to pre-exercise levels at 2h and 24h. Acute exercise transiently increases circulating TANG, TEM and progenitor cells with greater increases evident following very high intensity sprint exercise than following prolonged continuous paced endurance exercise.

Angiogenic miRNAs and related TIE2-expressing monocytes impact outcome in human cholangiocarcinoma

Background: Angiopoietins (Angs) and angiogenic microRNAs are associated with prognosis in tumors. Monocyte subsets express Ang-receptor TIE2 (TEMs) and exert pro-angiogenic properties associated with prognosis. However, little is known regarding their influence on tumor progression in human cholangiocarcinoma (CCA) Methods: We analyzed surgical specimens of intrahepatic CCA (n = 88) immunohistologically for distribution of Angs and TEMs. We tested miR targeting genes encoding Angs to be associated with tumor growth (n=44). MiRNA expression and abundance of TEMs were correlated with clinicopathologic characteristics, recurrence and patients’ survival Results: Absence of TEMs in tumor correlated with elevated CA19-9 serum levels. High Ang1 expression associated with reduced lymphangiosis carcinomatosa (all ρ<0.05). Patients characterized by invading TEMs showed a trend to reduced tumor recurrence and increased survival (ρ=0.159 and ρ=0.185). High miR-126 or low miR-128 expression was associated with improved survival (all p<0.05). In a multivariate analysis TEMs, miR-126 and low miR-128 were confirmed as independent prognosticators for survival (all p<0.05) Conclusion: TEMs define a subgroup of patients with improved tumor characteristics and prognosis. Our study provides first evidence that angiogenic miRNAs associate with survival in CCA. Besides suggested functional links between miRNA expression profiles, angiopoietins and TEMs, our data have possible clinical implications as novel diagnostic tools

Angiogenic miRNAs and related TIE2-expressing monocytes impact outcome in human cholangiocarcinoma

Angiogenic miRNAs and related TIE2-expressing monocytes impact outcome in human cholangiocarcinoma

Angiogenic miRNAs, the angiopoietin axis and related TIE2-expressing monocytes affect outcomes in cholangiocarcinoma.

BackgroundTumour angiogenesis is modulated on both an epigenetic and protein level and has potential implications for immune cell responses. However, the importance of related angiogenic biomarkers in cholangiocarcinoma (CCA) is unknown. This study assessed human CCA samples for the expression of angiogenesis-associated microRNAs, angiopoietins (Angs) and monocytes expressing the Ang-receptor, TIE2, with regards to prognostic significance after liver resection.MethodsAngiogenic miRNAs were analysed in frozen samples of intrahepatic CCA (iCC; n = 43) and hilar CCA (HC; n = 45). Ang-1 and Ang-2, as well as TIE2-expressing monocytes (TEMs), were detected in paraffin-embedded iCC sections (n = 88). MiRNA expression and the abundance of TEMs and Angs were correlated with clinicopathological characteristics and survival.ResultsMiR-126 was downregulated in 76.7% of all CCA samples, with high relative expression associated with smaller tumours and reduced lymph node metastasis. High Ang-1 expression was associated with less lymphangiosis carcinomatosa and better histological grading (all p < 0.05). The absence of TEMs in iCC correlated with elevated CA19-9 levels. High relative miR-126 and low miR-128 levels were associated with improved survival in iCC and HC, respectively (all p < 0.05). High miR-126, low miR-128 and TEMs were independent prognostic factors for recurrence-free and overall survival (all p < 0.05).ConclusionsThese results suggest that angiogenic miRNAs, Angs and TEMs are of prognostic value in CCA. In addition to the possible functional links between angiogenic miRNA expression profiles, Angs and immune-cell responses by TEMs, these data have clinical implications as novel diagnostic tools.

TIE2-expressing monocytes and M2-polarized macrophages impact survival and correlate with angiogenesis in adenocarcinoma of the pancreas.

IntroductionM2-polarized tumor-associated macrophages (TAMs) and TIE2-expressing monocytes (TEMs) are associated with angiogenesis and have been identified as a potential prognostic marker in several solid tumors, including hepatobiliary malignancies. However, little is known regarding their influence on tumor progression and patient survival in pancreatic ductal adenocarcinoma (PDAC).ResultsPatients with tumors characterized by the presence of CD163+ TAMs or TEMs in TCA or TIF, respectively, showed a significantly decreased 1-, 3- and 5-year overall and recurrence-free survival compared to patients without CD163+ TAMs or TEMs (all ρ < 0.05). Patients with TEMs in TCA showed a higher incidence of tumor recurrence (ρ < 0.05). Furthermore, the presence of CD163+ TAMs was associated with a higher tumor MVD (ρ < 0.05).ConclusionsPresence of M2-polarized TAMs and TEMs is associated with a decreased overall and recurrence-free survival of patients with PDAC.Materials and methodsThe localization and density of CD163+ M2-polarized TAMs and TEMs were quantified in the tumor central area (TCA) and tumor-infiltrating front (TIF) in human PDAC tissue (n = 106) and correlated to clinicopathological characteristics, tumor recurrence rates and patient survival. In parallel, tumor microvascular density (MVD) and the density of angiopoietin-positive tumor cells were quantified. Statistical analysis was performed using SPSS software.

Abstract 5207: HIF-1α regulates the Tie2 receptor on Tie2-expressing monocytes in PyMT breast tumors and augments angiogenic function and metastatic potential

Abstract Tissue oxygenation in the tumor microenvironment serves as a significant parameter in tumor pathophysiology. In fact, normalization of tumor oxygen is associated with inhibition of tumor growth and metastatic capacity. Irregular tumor vessels produced during tumor angiogenesis have low blood perfusion; thus, oxygen transport is decreased in tumors. Tie2-expressing monocytes (TEMs) are a distinct subset of proangiogenic monocytes selectively recruited to tumors in breast cancer patients. Due to the hypoxic nature of the tumor microenvironment, we investigated if oxygen regulates the trafficking of these cells into tumors or if oxygen regulates monocyte differentiation into TEMs once inside the tumor proper. To understand the differentiation of F4/80+/Tie2- cells to Tie2-positivity, we orthotopically implanted PyMT breast tumor cells containing particulate lithium octa-n-butoxy-naphthalocyanine (LiNcBuO) into the mammary fat pads of LysM-Cre control and HIF-1αfl/fl/LysM-Cre mice and evaluated tissue oxygenation by electron paramagnetic resonance (EPR), TEM infiltration, tumor angiogenesis, and metastatic potential. Longitudinal monitoring of physiologic oxygen in tumors using EPR demonstrates the significant role of oxygen-driven TEM regulation in tumor angiogenesis and progression. Citation Format: Kayla J. Steinberger, Mary Forget, Xiaokui Mo, Randall Evans, Amy Gross, Leni Moldovan, Andrey Bobko, Valery Khramstov, Clay B. Marsh, Timothy D. Eubank. HIF-1α regulates the Tie2 receptor on Tie2-expressing monocytes in PyMT breast tumors and augments angiogenic function and metastatic potential [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5207.