MicroRNA-466 and microRNA-200 increase endothelial permeability in hyperglycemia by targeting Claudin-5.

Endothelial cell (EC) permeability is essential to vascular homeostasis in diabetes. MicroRNAs are critical gene regulators whose roles in the EC permeability have yet to be characterized. This study aims to examine the change in cell permeability induced by miR-200 and miR-466 in ECs. Human aortic ECs and dermal microvascular ECs from healthy subjects and type 2 diabetic patients were used. Our in vitro experiments unveiled higher expressions of miR-200 family members and miR-466 in diabetic ECs and in healthy ECs when exposed to high glucose. Overexpression of both miR-200 and miR-466 significantly increased EC permeability through transcriptional suppression of Claudin-5, the cell tight junction protein, by directly binding to its 3' untranslated region. In a mouse model of chronic hyperglycemia mimicking type 2 diabetes in humans (db/db mice), the delayed closure rate of a full-thickness excisional wound was partly rescued by topical application of the miR-200 inhibitor. The topical application of both miR-200 and miR-466 inhibitors exhibited improved efficacy in accelerating wound closure compared with the topical application of miR-200 inhibitor alone. Our study demonstrated the potentially effective approach of miR-200/miR-466 cocktail inhibition to restore vascular integrity and tissue repair in hyperglycemia.

Methylglyoxal triggers human aortic endothelial cell dysfunction via modulation of the KATP/MAPK pathway.

Endothelial dysfunction is a key risk factor in diabetes-related multiorgan damage. Methylglyoxal (MGO), a highly reactive dicarbonyl generated primarily as a by-product of glycolysis, is increased in both type 1 and type 2 diabetic patients. MGO can rapidly bind with proteins, nucleic acids, and lipids, resulting in structural and functional changes. MGO can also form advanced glycation end products (AGEs). How MGO causes endothelial cell dysfunction, however, is not clear. Human aortic endothelial cells (HAECs) from healthy (H-HAECs) and type 2 diabetic (D-HAECs) donors were cultured in endothelial growth medium (EGM-2). D-HAECs demonstrated impaired network formation (on Matrigel) and proliferation (MTT assay), as well as increased apoptosis (caspase-3/7 activity and TUNEL staining), compared with H-HAECs. High glucose (25 mM) or AGEs (200 ng/ml) did not induce such immediate, detrimental effects as MGO (10 µM). H-HAECs were treated with MGO (10 µM) for 24 h with or without the ATP-sensitive potassium (KATP) channel antagonist glibenclamide (1 µM). MGO significantly impaired H-HAEC network formation and proliferation and induced cell apoptosis, which was reversed by glibenclamide. Furthermore, siRNA against the KATP channel protein Kir6.1 significantly inhibited endothelial cell function at basal status but rescued impaired endothelial cell function upon MGO exposure. Meanwhile, activation of MAPK pathways p38 kinase, c-Jun NH2-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) (determined by Western blot analyses of their phosphorylated forms, p-JNK, p-p38, and p-ERK) in D-HAECs were significantly enhanced compared with those in H-HAECs. MGO exposure enhanced the activation of all three MAPK pathways in H-HAECs, whereas glibenclamide reversed the activation of p-stress-activated protein kinase/JNK induced by MGO. Glyoxalase-1 (GLO1) is the endogenous MGO-detoxifying enzyme. In healthy mice that received an inhibitor of GLO1, MGO deposition in aortic wall was enhanced and endothelial cell sprouting from isolated aortic segment was significantly inhibited. Our data suggest that MGO triggers endothelial cell dysfunction by activating the JNK/p38 MAPK pathway. This effect arises partly through activation of KATP channels. By understanding how MGO induces endothelial dysfunction, our study may provide useful information for developing MGO-targeted interventions to treat vascular disorders in diabetes.

Ameliorating Methylglyoxal-Induced Progenitor Cell Dysfunction for Tissue Repair in Diabetes.

Patient-derived progenitor cell (PC) dysfunction is severely impaired in diabetes, but the molecular triggers that contribute to mechanisms of PC dysfunction are not fully understood. Methylglyoxal (MGO) is one of the highly reactive dicarbonyl species formed during hyperglycemia. We hypothesized that the MGO scavenger glyoxalase 1 (GLO1) reverses bone marrow-derived PC (BMPC) dysfunction through augmenting the activity of an important endoplasmic reticulum stress sensor, inositol-requiring enzyme 1α (IRE1α), resulting in improved diabetic wound healing. BMPCs were isolated from adult male db/db type 2 diabetic mice and their healthy corresponding control db/+ mice. MGO at the concentration of 10 µmol/L induced immediate and severe BMPC dysfunction, including impaired network formation, migration, and proliferation and increased apoptosis, which were rescued by adenovirus-mediated GLO1 overexpression. IRE1α expression and activation in BMPCs were significantly attenuated by MGO exposure but rescued by GLO1 overexpression. MGO can diminish IRE1α RNase activity by directly binding to IRE1α in vitro. In a diabetic mouse cutaneous wound model in vivo, cell therapies using diabetic cells with GLO1 overexpression remarkably accelerated wound closure by enhancing angiogenesis compared with diabetic control cell therapy. Augmenting tissue GLO1 expression by adenovirus-mediated gene transfer or with the small-molecule inducer trans-resveratrol and hesperetin formulation also improved wound closure and angiogenesis in diabetic mice. In conclusion, our data suggest that GLO1 rescues BMPC dysfunction and facilitates wound healing in diabetic animals, at least partly through preventing MGO-induced impairment of IRE1α expression and activity. Our results provide important knowledge for the development of novel therapeutic approaches targeting MGO to improve PC-mediated angiogenesis and tissue repair in diabetes.

A phase 1 trial of vadastuximab talirine combined with hypomethylating agents in patients with CD33-positive AML.

Treatment of acute myeloid leukemia (AML) among the elderly is challenging because of intolerance of intensive therapy and therapy-resistant biology. Hypomethylating agents (HMAs) are commonly used, with suboptimal outcomes. Vadastuximab talirine is a CD33-directed antibody conjugated to pyrrolobenzodiazepine (PBD) dimers. Preclinically, HMAs followed by vadastuximab talirine produced upregulated CD33 expression, increased DNA incorporation by PBD, and enhanced cytotoxicity. A combination cohort in a phase 1 study (NCT01902329) assessed safety, tolerability, and activity of vadastuximab talirine with HMAs. Those eligible had Eastern Cooperative Oncology Group status 0 to 1 and previously untreated CD33-positive AML, and declined intensive therapy. Vadastuximab talirine was administered intravenously at 10 µg/kg on last day of HMA (azacitidine or decitabine) infusion in 4-week cycles. Among 53 patients treated, the median age was 75 years. Patients had adverse (38%) or intermediate (62%) cytogenetic risk. Median treatment duration was 19.3 weeks. No dose-limiting toxicities were reported. The majority of adverse events were a result of myelosuppression, with some causing therapy delays. Thirty- and 60-day mortality rates were 2% and 8%, respectively. The composite remission rate (complete remission [CR] and CR with incomplete blood count recovery) was 70%. Fifty-one percent of remissions were minimal residual disease-negative by flow cytometry. Similarly high remission rates were observed in patients with secondary AML, aged at least 75 years, and with adverse cytogenetic risk. Median relapse-free survival and overall survival were 7.7 and 11.3 months, respectively. Compared with historical data for HMA monotherapy, the combination of vadastuximab talirine with HMAs produced a high remission rate, but was accompanied by increased hematologic toxicity.

Disruption of GPR35 Exacerbates Dextran Sulfate Sodium-Induced Colitis in Mice.

BACKGROUND: G protein-coupled receptor 35 (GPR35) is an orphan receptor and is vastly expressed in immune cells and gastrointestinal cells, suggesting the potential physiological importance of GPR35 in these cells. Here, we tested the hypothesis that the lack of GPR35 expression in the colon mucosa exacerbates the severity of dextran sulfate sodium (DSS)-induced experimental colitis in mice. METHODS: Colitis was induced in GPR35 wild-type (GPR35+/+) and GPR35 knockout (GPR35-/-) mice through the administration of DSS in drinking water for 5 days followed by regular facility water for 1 day. Induction of colitis was evaluated by measuring relative body weight loss, clinical illness scores, and morphological changes in the colon. Abolition of Gpr35 gene expression in the colon mucosa of GPR35-/- mice was confirmed by quantitative real-time PCR (qPCR). Gene expressions of inflammatory and tissue remodeling cytokines were detected by qPCR. Human colorectal epithelial Caco cells were transfected with siRNA against GPR35 before treated with 1% DSS in vitro. Protein expressions were measured using Western blot. RESULTS: GPR35-/- mice receiving DSS showed a significantly worsened colitis disease with profound loss of body weight and a considerable amount of severe clinical illness compared to GPR35+/+ mice that received DSS. The histology of colon sections from GPR35-/- mice showed extensive pathological changes including submucosal edema, diffuse ulcerations, and evidence of complete loss of crypts compared to wild-type mice. The mean histopathological score was significantly higher in GPR35-/- mice as compared to GPR35+/+ mice. The qPCR data revealed significant expression of pro-inflammatory and tissue remodeling cytokines in GPR35-/- colon mucosa, including IL-1ß, CXCL1, CXCL2, CCL2, HMGB1, TGFß1, TGFß3, MMP1/9/12. The protein expressions of Zonula occludens-1, E-cadherin, Claudin1 were decreased upon knocking down GPR35 with or without 1% DSS treatment. CONCLUSIONS: Our experimental data suggest that lack of GPR35 resulted in worsened disease outcome in DSS-induced experimental colitis, indicating that GPR35 could play a crucial role in protecting from colonic inflammation and serve as a therapeutic target.

A phase 1 trial of vadastuximab talirine as monotherapy in patients with CD33-positive acute myeloid leukemia.

Vadastuximab talirine (SGN-CD33A, 33A) is an antibody-drug conjugate consisting of pyrrolobenzodiazepine dimers linked to a monoclonal antibody targeting CD33, which is expressed in the majority of acute myeloid leukemia (AML) patients. This phase 1 study evaluated the safety, pharmacokinetics, and preliminary activity of vadastuximab talirine and determined the recommended monotherapy dose in patients with relapsed or refractory AML. Additional expansion cohorts tested vadastuximab talirine in specific subpopulations of relapsed AML, and in a cohort of older, treatment-naive patients. Patients received vadastuximab talirine IV on day 1 (5-60 µg/kg) or on days 1 and 4 (20 µg/kg) of 21-day cycles. A total of 131 patients (median age, 73 years [range, 26-89 years]) had intermediate I-II (48%) or adverse (34%) risk by European LeukemiaNet classification; 50% of patients had underlying myelodysplasia. Two dose-limiting toxicities (grade 2 pulmonary embolism and grade 4 hypocellular marrow) occurred during dose finding. Most adverse events (AEs) were consistent with myelosuppression; nonhematologic AEs included fatigue, nausea, and diarrhea. The 30-day mortality was 8%. At the recommended monotherapy dose of 40 µg/kg, the complete remission + CRi rate was 28% (5 of 18 patients); 50% of patients who responded achieved minimal residual disease negativity. In patients across dose levels who achieved CR or CRi, the median time to full count recovery was 6.4 weeks for neutrophils (≥1000/µL) and 10.6 weeks for platelets (≥100 × 109/L). Vadastuximab talirine demonstrates activity and a tolerable safety profile as a single agent in patients with AML. The recommended monotherapy dose of vadastuximab talirine is 40 µg/kg. This trial was registered at www.clinicaltrials.gov as # NCT01902329.

Immunization against HIF-1α Inhibits the Growth of Basal Mammary Tumors and Targets Mammary Stem Cells In Vivo.

Purpose: Triple-negative breast cancer (TNBC) represents a cancer stem cell-enriched phenotype. Hypoxia-inducible factor-1α (HIF-1α) induces the expression of proteins associated with stemness and is highly upregulated in TNBC. We questioned whether HIF-1α was immunogenic and whether vaccination targeting HIF-1α would impact the growth of basal-like mammary tumors in transgenic mice.Experimental Design: We evaluated HIF-1α-specific IgG in sera from controls and patients with breast cancer. Class II epitopes derived from the HIF-1α protein sequence were validated by ELISPOT. To assess therapeutic efficacy, we immunized Tg-MMTVneu and C3(1)Tag mice with HIF-1α Th1-inducing peptides. Stem cells were isolated via magnetic bead separation. Levels of HIF-1α and stem cells in the tumor were quantitated by Western blotting and flow cytometry.Results: The magnitude (P < 0.001) and incidence (P < 0.001) of HIF-1α-specific IgG were elevated in TNBC patients compared with controls. Both breast cancer patients and donors showed evidence of HIF-1α-specific Th1 and Th2 immunity. Three HIF-1α-specific Th1 class II restricted epitopes that were highly homologous between species elicited type I immunity in mice. After HIF-1α vaccination, mammary tumor growth was significantly inhibited in only C3(1)Tag (basal-like/stem cellhigh; P < 0.001) not TgMMTV-neu (luminal/neu/stem celllow; P = 0.859) murine models. Vaccination increased type I T cells in the tumor (P = 0.001) and decreased cells expressing the stem cell marker, Sca-1, compared with controls (P = 0.004).Conclusions: An HIF-1α vaccine may be uniquely effective in limiting tumor growth in TNBC. Inhibiting outgrowth of breast cancer stem cells via active immunization in the adjuvant setting may impact disease recurrence. Clin Cancer Res; 23(13); 3396-404. ©2016 AACR.

Brentuximab vedotin in patients aged 60 years or older with relapsed or refractory CD30-positive lymphomas: a retrospective evaluation of safety and efficacy.

Older adults constitute a significant proportion of the cancer population, but are underrepresented in clinical trials. We conducted a retrospective analysis of the safety and efficacy of brentuximab vedotin in adults ≥ 60 years with relapsed CD30-positive lymphomas. Baseline characteristics and safety data were compared for older (median age 66) and younger patients (< 60 years, median age 32). Exposure to brentuximab vedotin was comparable. Older patients had more preexisting conditions (median 11 vs. 6) and were receiving more concomitant medications (median 7.5 vs. 4). Higher rates of anemia (30% vs. 10%), peripheral sensory neuropathy (60% vs. 46%), fatigue (58% vs. 43%) and adverse events ≥ grade 3 (70% vs. 56%) occurred in older patients. Objective response rates were 56% and 100% in older patients with Hodgkin lymphoma and systemic anaplastic large cell lymphoma, respectively. With appropriate monitoring, brentuximab vedotin may represent a meaningful clinical option for older patients with relapsed CD30-positive lymphomas.

Brentuximab vedotin combined with ABVD or AVD for patients with newly diagnosed Hodgkin's lymphoma: a phase 1, open-label, dose-escalation study.

BACKGROUND: Roughly 70-80% of patients with advanced stage Hodgkin's lymphoma are cured with various first-line and second-line treatments, including ABVD, BEACOPP, and stem-cell transplantation. Brentuximab vedotin has shown significant clinical activity, with a manageable safety profile, in patients with relapsed or refractory Hodgkin's lymphoma. We aimed to assess the safety and early clinical efficacy of this drug as first-line treatment in combination with standard or modified-standard treatment in patients with previously untreated Hodgkin's lymphoma. METHODS: We did a phase 1, open-label, dose-escalation safety study comparing brentuximab vedotin in combination with standard (ABVD) or a modified-standard (AVD) treatment. Patients were enrolled into the groups sequentially. Main entry criteria were newly diagnosed, treatment-naive, CD30-positive patients with Hodgkin's lymphoma who had histologically confirmed stage IIA bulky disease or stage IIB-IV disease and an Eastern Cooperative Oncology Group performance status of two or less. Patients received doses of 0·6, 0·9, or 1·2 mg/kg brentuximab vedotin by intravenous infusion every 2 weeks with either ABVD (25 mg/m(2) doxorubicin, 10 units/m(2) bleomycin, 6 mg/m(2) vinblastine, and 375 mg/m(2) dacarbazine) or AVD (ABVD modified regimen without the inclusion of bleomycin) for up to six cycles. Our primary objectives were to assess the safety profile and establish the maximum tolerated dose (MTD) of brentuximab vedotin in combination with ABVD and AVD. The safety profile and MTD was assessed for the safety population. The study has completed and the final analysis is presented. This study was registered with ClinicalTrials.gov, number NCT01060904. FINDINGS: Between Jan 29, 2010, and Sept 17, 2012, 51 patients were enrolled and received at least one dose of brentuximab vedotin. The maximum tolerated dose of brentuximab vedotin when combined with ABVD or AVD was not exceeded at 1·2 mg/kg. 21 (95%) of 22 patients given brentuximab vedotin and ABVD achieved complete remission, as did 24 (96%) of 25 patients given brentuximab vedotin and AVD. Adverse events were generally grade 1 or 2; however, an unacceptable number of patients in the brentuximab vedotin and ABVD groups had pulmonary toxic effects (11 [44%] of 25), which exceeded the historical incidence for ABVD alone. No patients experienced pulmonary toxic effects when treated with brentuximab vedotin plus AVD. The most common grade 3 or worse events were neutropenia (20 [80%] of 25 patients in the brentuximab vedotin and ABVD group vs 20 [77%] of 26 patients in the brentuximab vedotin and AVD group), anaemia (five [20%] vs three [12%]), febrile neutropenia (five [20%] vs two [8%]), pulmonary toxic effects (six [24%] vs 0), syncope (three [12%] vs two [8%]), dyspnoea (three [12%] vs one [4%]), pulmonary embolism (three [12%] vs 0), fatigue (one [4%] each), and leucopenia (one [4%] each). Serious events occured in 41% of all patients (14 [56%] in the brentuximab vedotin and ABVD group and seven [27%] in the brentuximab vedotin and AVD group). Serious events occurring in 10% of patients or more overall were febrile neutropenia (four [16%] in the brentuximab vedotin and ABVD group vs two [8%] in the brentuximab vedotin and AVD group), and, in the brentuximab vedotin and ABVD group only, pulmonary toxic effects (six [24%]). INTERPRETATION: Brentuximab vedotin should not be given with bleomycin in general or specifically as first-line therapy for patients with treatment naive, advanced stage Hodgkin's lymphoma. 1·2 mg/kg brentuximab vedotin combined with AVD given every 2 weeks was generally well tolerated by patients. At present, a phase 3 trial comparing brentuximab vedotin plus AVD to ABVD alone is ongoing (ClinicalTrials.gov, number NCT01712490) and will formally assess whether brentuximab vedotin plus AVD might redefine therapy in treatment-naive patients with Hodgkin's lymphoma. FUNDING: Seattle Genetics Inc and Takeda Pharmaceuticals International Co.

A multiantigen vaccine targeting neu, IGFBP-2, and IGF-IR prevents tumor progression in mice with preinvasive breast disease.

A multiantigen multipeptide vaccine, targeting proteins expressed in preinvasive breast lesions, can stimulate type I CD4(+) T cells which have been shown to be deficient in both patients with breast cancer and mice that develop mammary tumors. Transgenic mice (TgMMTV-neu) were immunized with a multiantigen peptide vaccine specific for neu, insulin-like growth factor-binding protein 2 and insulin-like growth factor receptor-I at a time when some of the animals already had preinvasive lesions (18 weeks of age). Although immunization with each individual antigen was partially effective in inhibiting tumor growth, immunization with the multiantigen vaccine was highly effective, blocking development of palpable lesions in 65% of mice and slowing tumor growth in the infrequent palpable tumors, which did arise. Protection was mediated by CD4(+) T cells, and the few slow-growing tumors that did develop demonstrated a significant increase in intratumoral CD8(+) T cells as compared with controls (P = 0.0007). We also combined the vaccine with agents that were, by themselves, partially effective inhibitors of tumor progression in this model; lapatinib and the RXR agonist bexarotene. Although the combination of lapatinib and vaccination performed similarly to vaccination alone (P = 0.735), bexarotene and vaccination significantly enhanced disease-free survival (P < 0.0001), and approximately 90% of the mice showed no pathologic evidence of carcinomas at one year. The vaccine also demonstrated significant clinical efficacy in an additional transgenic model of breast cancer (TgC3(I)-Tag). Chemoimmunoprevention combinations may be an effective approach to breast cancer prevention even when the vaccine is administered in the presence of subclinical disease.

Limiting the daily total nucleated cell dose of cryopreserved peripheral blood stem cell products for autologous transplantation improves infusion-related safety with no adverse impact on hematopoietic engraftment.

Cryopreserved peripheral blood stem cell (PBSC) products can induce a number of infusion-related adverse reactions, including life-threatening cardiac, neurologic, and other end-organ complications. Preliminary analyses suggested limiting the daily total nucleated cell dose infused might decrease the incidence of these adverse effects. A policy change implemented in December 2007, limiting the total nucleated cell (TNC) dose to <1.63 × 10(9) TNC/kg/day, allowed us to assess the impact of this intervention on infusion-related safety, infusion schedules, engraftment, and costs in cohorts of patients undergoing autologous stem cell transplants (ASCTs) 2 years before (325 ASCTs in 288 patients) and 2 years after the policy change (519 ASCTs in 479 patients). The percentage of autologous transplant patients requiring multiple day infusions increased from 6% to 24%. Concurrently, the incidence of infusion-related grade 3-5 severe infusion-related adverse events (SAEs) decreased significantly, from 4% (13 of 325) prepolicy change to 0.6% (3 of 519) postpolicy change (P < .0004). Multiday infusions were not associated with increased time to neutrophil or platelet engraftment or the costs of transplantation. We conclude that limiting the daily TNC dose improved the safety of this procedure without compromising engraftment or increasing the costs of the procedure.

Therapeutic cancer vaccines and translating vaccinomics science to the global health clinic: emerging applications toward proof of concept.

As vaccines evolve to be a more common treatment for some cancers, further research is needed to improve the process of developing vaccines and assessing response to treatment. Vaccinomics involves a wide-ranging integration of multiple high throughput technologies including transcriptional, translational, and posttranslational population-based assessments of the human genome, transcriptome, proteome, and immunome. Vaccinomics combines the fields of immunogenetics, immunogenomics, immunoproteomics, and basic immunology to create vaccines that are tailor made to an individual or groups of individuals. This broad range of omics applications to tumor immunology includes antigen discovery, diagnostic biomarkers, cancer vaccine development, predictors of immune response, and clinical response biomarkers. These technologies have aided in the advancement of cancer vaccine development, as illustrated in examples including NY-ESO-1 originally defined by SEREX, and HER2/neu peptides analyzed via high-throughput epitope prediction methods. As technology improves, it presents an opportunity to improve cancer immunotherapy on a global scale, and attention must also be given to utilize these high-throughput methods for the understanding of cancer and immune signatures across populations.

Aberrant methylation of the maspin promoter is an early event in human breast cancer.

The maspin gene functions as a tumor suppressor in human breasts, and its expression is frequently lost during breast cancer progression. In vitro models of human breast cancer indicate that the loss of maspin expression is closely linked to aberrant methylation of the maspin promoter. We conducted a study on 30 archival ductal carcinoma in situ (DCIS) specimens to determine if aberrant methylation of the maspin promoter occurred in vivo, and whether it occurred early in breast cancer evolution. Healthy tissue obtained from reduction mammoplasty was used as normal control. Results from immunohistochemical analysis indicate that maspin expression is lost in a substantial fraction of DCIS specimens (57%). Bisulfite sequencing of DNA isolated from laser capture-microdissected normal and neoplastic ducts showed that loss of maspin expression was often, but not always, linked to aberrant methylation of the maspin promoter, suggesting that other mechanisms, in addition to aberrant methylation, participate and/or cooperate to silence maspin gene expression. Taken together, these results indicate that aberrant methylation of the maspin promoter is an early event in human breast cancer.