Synergistic activation of RARß and RARγ nuclear receptors restores cell specialization during stem cell differentiation by hijacking RARα-controlled programs.

How cells respond to different external cues to develop along defined cell lineages to form complex tissues is a major question in systems biology. Here, we investigated the potential of retinoic acid receptor (RAR)-selective synthetic agonists to activate the gene regulatory programs driving cell specialization during nervous tissue formation from embryonic carcinoma (P19) and mouse embryonic (E14) stem cells. Specifically, we found that the synergistic activation of the RARß and RARγ by selective ligands (BMS641 or BMS961) induces cell maturation to specialized neuronal subtypes, and to astrocytes and oligodendrocyte precursors. Using RAR isotype knockout lines exposed to RAR-specific agonists, interrogated by global transcriptome landscaping and in silico modeling of transcription regulatory signal propagation, revealed major RARα-driven gene programs essential for optimal neuronal cell specialization and hijacked by the synergistic activation of the RARß and RARγ receptors. Overall, this study provides a systems biology view of the gene programs accounting for the previously observed redundancy between RARs, paving the way toward their potential use for directing cell specialization during nervous tissue formation.

Comparison of efficacy and safety of erenumab between over and under 65-year-old refractory migraine patients: a pivotal study.

Previous studies reported a positive effect of anti-CGRP monoclonal antibodies (mAbs) in migraine prevention, either in over (O65) and under (U65) 65-year-aged patients. The aim of our study was to evaluate and compare real-life efficacy and safety of mAbs between young and elder migraine patients. Fifteen O65 and fifteen U65 patients, treated with monthly mAbs for 6 months, were enrolled and matched for sex, monthly headache days (MHD), and monthly migraine days (MMD) at baseline. Between-group differences in MHD and MMD, number of pills and days of acute medication intake, HIT-6, MIDAS, Numeric Rating Scale (NRS), and Allodynia Symptom Checklist (ASC-12) were assessed after 3 (M3) and 6 (M6) months of treatment. Adverse events (AEs) were also investigated. In each group, thirteen patients (87%) were women and nine (60%) had chronic migraine. Baseline mean MHD and MMD of both groups were 20 (SD 9.6). Mean age was 70 (65-76) and 45 (19-55) in the O65 and U65 group, respectively. Before starting mAbs, patients have tried an average of 4 preventives in both groups. After 3 and 6 months of treatment, both groups had a reduction of all clinical features under examination, without statistically significant differences between groups. A similar proportion of patients in each group complained of AEs (M3 and M6, p = 1.0). Our real-life data showed that treatment with mAbs is as effective and safe in O65 as U65 migraine patients. Further studies are needed to confirm these findings.

Serum neurofilaments increase at progressive multifocal leukoencephalopathy onset in natalizumab-treated multiple sclerosis patients.

This study analyzed serum neurofilament light chains (NfL) in 2 European cohorts of 312 multiple sclerosis (MS) patients to investigate whether NfL are biomarkers of progressive multifocal leukoencephalopathy (PML) during natalizumab treatment. The cohort comprised 25 PML, 136 natalizumab-treated, and 151 untreated MS patients. Patients subsequently developing PML had similar NfL to other natalizumab-treated MS patients. At PML onset, NfL were 10-fold higher than in the pre-PML condition and in natalizumab-treated or untreated MS patients, and NfL continued to increase until onset of immune reconstitution inflammatory syndrome. The results suggest that in natalizumab-treated patients, NfL may represent an early and accessible marker of PML. Ann Neurol 2019;85:606-610.

End-of-life management in intensive care units: a multicentre observational prospective cohort study.

BACKGROUNDS: The study was conducted to evaluate intensive care unit (ICU) patients that ultimately died but could have met criteria for end-of-life management/palliative care (ELM-PC), and to analyse the application of components of palliative care, either "unperformed procedures" or elements of "futile/unnecessary treatment". METHODS: An observational prospective cohort in five ICUs in Southern Brazil. Adult patients who died were evaluated, searching for criteria for ELM-PC. The correct application of nine preselected items by the ICU team was studied. RESULTS: Among 253 admissions, 52 patients died; among these, 38.5% met criteria for ELM-PC. Among ELM-PC candidates (n = 20), the ELM-PC was started later (after day 3) in 60%, and only three patients received adequate palliative care. "Analgesia" and "daily family interviews" were the most correctly applied ELM-PC elements. "Terminal extubation/weaning" was not performed in any of the patients. A reduction in the lifespan from the onset of ELM-PC to death was observed in patients who underwent "correct" interventions - 66.6% died on the first day of ELM-PC. CONCLUSIONS: In a patient cohort from a low-medium-income country, one-third of patients who died in the ICU had criteria (indications) for ELM-PC; however, the palliative care was adequately performed for only 15% of patients, with great heterogeneity and delays regarding its initiation.

Assessing the role of innovative therapeutic paradigm on multiple sclerosis treatment response.

OBJECTIVE: Within the last decade, many changes have been made to the management of patients with multiple sclerosis (MS). The aim of our study was to investigate the global impact of all these changes on the disease's course. MATERIALS AND METHODS: This single-centre study was carried out on patients with multiple sclerosis (pwMS) who started treatment with first-line disease-modifying therapies. We have compared three large cohorts of patients with MS diagnosis, for three consecutive periods within July 2001, August 2001-December 2005, and January 2006-September 2011. RESULTS: A total of 1068 relapsing-remitting pwMS cases were included. Patients in the last cohort began treatment earlier (P < 0.0001), started more frequent treatment with high-dose interferon beta or glatiramer acetate (P < 0.0001), and had experienced a more frequent treatment escalation strategy (P = 0.004) than patients in other cohorts. The multivariate analysis adjusted for baseline characteristics showed that pwMS of the last cohort had a high probability of showing no evidence of disease activity (NEDA3) at 4 years (OR 3.22, 95% CIs 1.89-5.47; P < 0.0001). These results were confirmed in a propensity score analysis. CONCLUSIONS: Our study showed an improvement over the last 15 years in the treatment response; this observation can be associated to a paradigm shift in MS treatment strategies.

Hypercalcemia and acute renal insufficiency following use of a veterinary supplement / Hipercalcemia e insuficiência renal aguda após uso de suplemento veterinário

Abstract A previously healthy 24 yo male presented with a two-month history of epigastric pain, nausea, vomiting, fatigue and malaise. He reported abuse of different substances, including an injectable veterinary vitamin compound, which contains high doses of vitamin A, D and E, and an oily vehicle that induces local edema and enhances muscle volume. Serum creatinine was 3.1 mg/dL, alanine transaminase 160 mg/dL, aspartate transaminase 11 mg/dL, total testosterone 23 ng/dL, 25-OH-vitamin D >150 ng/mL (toxicity >100), 1,25-OH-vitamin D 80 pg/mL, vitamin A 0.7 mg/dL, parathormone <3 pg/mL, total calcium 13.6 mg/dL, 24-hour urinary calcium 635 mg/24h (RV 42-353). A urinary tract ultrasound demonstrated signs of parenchymal nephropathy. The diagnosis was hypercalcemia and acute renal failure secondary to vitamin D intoxication. He was initially treated with intravenous hydration, furosemide and prednisone. On the fifth day of hospitalization a dose of pamidronate disodium was added. The patient evolved with serum calcium and renal function normalization. Thirty days later he presented normal clinical and laboratory tests, except 25-OH-vitamin D that was persistently increased (107 ng/mL), as it may take several months to normalize. This case report is a warning of the risks related to the use of veterinary substances for aesthetics purposes.

Resumo Um paciente de 24 anos do sexo masculino, previamente hígido, apresentou-se com uma história de dois meses de dor epigástrica, náuseas, vômitos, fadiga e mal-estar. Ele relatava abuso de diferentes substâncias, incluindo um composto vitamínico veterinário injetável contendo altas doses de vitamina A, D e E, e um veículo oleoso que induz edema local com aumento de volume muscular. A creatinina sérica estava 3,1 mg/dL, alanina transaminase 160 mg/dL, aspartato transaminase 11 mg/dL, testosterona total 23 ng/dL, 25-OH-vitamina D > 150 ng/mL (toxicidade > 100), 1,25-OH-vitamina D 80 pg/mL, vitamina A 0,7 mg/dL, paratormônio < 3 pg/mL, cálcio total 13,6 mg/dL, cálcio urinário de 24h 635 mg/24h (VR 42-353). Uma ultrassonografia do trato urinário demonstrou sinais de nefropatia parenquimatosa. O diagnóstico foi hipercalcemia e insuficiência renal aguda secundária a intoxicação por vitamina D. Ele foi tratado inicialmente com hidratação intravenosa, furosemida e prednisona. No quinto dia de hospitalização uma dose de pamidronato dissódico foi adicionada. O paciente evoluiu com normalização do cálcio sérico e da função renal. Trinta dias depois ele apresentou testes clínicos e laboratoriais normais, exceto a 25-OH-vitamina D que estava persistentemente elevada (107 ng/mL), já que ela pode demorar vários meses para normalizar. Este relato de caso é um alerta aos riscos relacionados ao uso de substâncias veterinárias para fins estéticos.

Natalizumab versus fingolimod in patients with relapsing-remitting multiple sclerosis non-responding to first-line injectable therapies.

BACKGROUND: Natalizumab and fingolimod have not been compared in controlled trials but only in observational studies, with inconclusive results. OBJECTIVES: The objective of this study is to compare the effect of natalizumab and fingolimod in reducing disease activity in relapsing-remitting multiple sclerosis (RRMS). METHODS: We included all consecutive RRMS patients switched from first-line agents (glatiramer acetate/interferons) to natalizumab or fingolimod, with a follow-up of 24 months. Data of relapses, Expanded Disability Status Scale score and brain magnetic resonance imaging (MRI) scans were collected. We used propensity score (PS) matching and intention-to-treat analysis. RESULTS: We retained 102 patients in each cohort after PS matching, with similar baseline characteristics. More patients discontinued natalizumab compared to fingolimod (33% vs 11%, p < 0.001), mainly for progressive multifocal leukoencephalopathy (PML) concern. No serious adverse events occurred in the two cohorts. Compared to fingolimod, the natalizumab group presented a higher percentage of relapse-free patients (66% vs 80%, p = 0.015), a higher percentage of disability-improved patients (6% vs 15%, p = 0.033), a lower percentage of MRI-active patients (38% vs 14%, p = 0.001) and a higher percentage of patients with no evidence of disease activity (NEDA-3; 44% vs 70%, p < 0.001) after 2 years of follow-up. Disability worsening was not statistically different in the two groups. CONCLUSION: Natalizumab is superior to fingolimod in RRMS patients non-responding to first-line agents.

Clinical and laboratory characteristics of patients with thyroid diseases with and without alanine aminotransferase levels above the upper tertile – Cross-sectional analytical study

Objective Thyroid disease affects 6.6% of the general population. The liver is fundamental in metabolizing thyroid hormones, and hepatocytes are often affected in thyroid disease. We aimed to compare clinical and laboratory parameters among thyroid disease patients with alanine aminotransferase (ALT) levels above vs. below the upper tertile. Subjects and methods A retrospective cross-sectional analytical study was conducted in the endocrinology clinic at Polydoro Ernani de São Thiago University Hospital. Patients with thyroid disease between August 2012 and January 2014 were included in the study. Clinical and laboratory parameters were collected from medical records. Results One hundred patients were included, of which 14.0% were male, with a mean age of 49.1 ± 14.4 years. ALT levels ranged from 9 to 90 U/L, and the ALT upper tertile was defined as 0,64 times the upper normal limit (xUNL). Patients with ALT levels above the upper tertile exhibited a higher proportion of systemic arterial hypertension (SAH), a higher mean abdominal circumference and a higher frequency of elevated TSH levels than did patients with ALT levels below the upper tertile. In multivariate analysis, ALT ≥ 0.64 (xUNL) was independently associated with abdominal circumference (odds ratio [OR] = 0.087, 95% confidence interval [CI] 0012-0167, P = 0.022). ALT (xUNL) correlated positively with total cholesterol (r = 0.213, P = 0.042). Conclusions In patients with thyroid diseases, it was observed that those with ALT above the upper tertile are associated with abdominal circumference and ALT levels correlate with total cholesterol.

Regulatory T-cell development and function are impaired in mice lacking membrane expression of full length intercellular adhesion molecule-1.

To further investigate the contribution of intercellular adhesion molecule-1 (ICAM-1) to adaptive immune responses, we analysed T-cell development and function in mice lacking full-length ICAM-1 (ICAM-1(tm1Jcgr) ). Compared with wild-type (ICAM-1(WT) ) mice, ICAM-1(tm1Jcgr) mice have impaired thymocyte development. Proportions and numbers of double negative, double positive, mature CD4(+) and CD8(+) thymocytes, as well as of regulatory T (Treg) cells were also significantly decreased. In the periphery, ICAM-1(tm1Jcgr) mice had significantly decreased proportions and numbers of naive and activated/memory CD4(+) and CD8(+) T cells, as well as of Treg cells, in lymph nodes but not in the spleen. In vitro activation of CD4(+) and CD8(+) T cells from ICAM-1(tm1Jcgr) mice with anti-CD3 antibodies and antigen-presenting cells (APCs) resulted in a significantly weaker proliferation, whereas proliferation induced with anti-CD3 and anti-CD28 antibody-coated beads was normal. In vivo immunization of ICAM-1(tm1Jcgr) mice resulted in normal generation of specific effector and memory immune responses that protect against a viral challenge. However, contrary to ICAM-1(WT) mice, immunization-induced specific effectors could not eradicate immunogen-expressing tumours. Treg cells from ICAM-1(tm1Jcgr) mice have abnormal activation and proliferation induced by anti-CD3 antibody and APCs, and have markedly decreased suppressive activity in vitro. In contrast to ICAM-1(WT) mice, they were unable to control experimentally induced colitis in vivo. Hence, our results further highlight the pleiotropic role of ICAM-1 in T-cell-dependent immune responses, with a major role in Treg cell development and suppressive function.

Escores de neuropatia periférica em diabéticos / Peripheral neuropathy scores in diabetic

OBJETIVO: Diabetes mellitus é uma doença crônica prevalente, associada a inúmeras complicações. A neuropatia periférica diabética é a mais comum, acometendo 50% dos diabéticos, mas muitas vezes não é diagnosticada. Por cursar com insensibilidade distal e alterações arquiteturais dos pés, predispõe a úlceras, podendo culminar no pé diabético com risco de amputação. O diabetes mellitus é responsável por 70% das amputações de membros, que poderiam ser prevenidas com o diagnóstico precoce da neuropatia periférica diabética. Sugere-se avaliar o grau de neuropatia em diabéticos por meio de escores, visando homogeneizar o diagnóstico, quantificar a prevalência e promover medidas preventivas. MÉTODOS: Realizou-se entrevista, exame físico e coleta de dados de diabéticos atendidos ambulatorialmente, para pontuação e qualificação no Escore de Sintomas Neuropáticos e no Escore de Comprometimento Neuropático, validados na língua portuguesa para avaliar neuropatia periférica diabética, além de análise das características clínicas e epidemiológicas associadas. RESULTADOS: Foram incluídos 116 pacientes, constatando-se neuropatia periférica diabética em 31,9%. Houve correlação significativa de neuropatia periférica diabética coma idade dos pacientes, mas não com as demais variáveis clínicas e laboratoriais. Os pacientes avaliados apresentaram médias de idade de 55±15 anos e tempo de diabetes de 14,8±10,9 anos, sendo predominantemente caucasianos, mulheres e portadores de diabetes mellitus tipo 2. Eram hipertensos 67,2% e 42,2%, obesos. CONCLUSÃO: A prevalência encontrada corrobora a literatura, embora poucos estudos tenham utilizado critérios similares para diagnosticar neuropatia periférica diabética. Empregando os escores padronizados, de baixo custo e fácil aplicação possibilitamos o diagnóstico precoce e embasado dessa entidade, sendo possível, com isso, reduzir a prevalência de graves complicações do pé diabético e disseminar informações a respeito.

OBJECTIVE: Diabetes mellitus is a prevalent chronic disease, associated with numerous complications. Diabetic peripheral neuropathy is the most common, affecting 50% of diabetics, although is often not diagnosed. Presenting with distal numbness and architectural alterations of the feet, it predisposes ulcers and may culminate in diabetic foot at risk for amputation. Diabetes mellitus is responsible for 70% of limb amputations, which could be prevented with early diagnosis of diabetic peripheral neuropathy. This study aims to evaluate the degree of neuropathy in diabetics through validated scores, in order to standardize the diagnosis, quantify the prevalence and promote preventive actions. METHODS: We performed an interview, physical examination and data collection of diabetic outpatients, for rating in the Neuropathy Symptom Score and the Neuropathy Disability Score, validated in Portuguese, to assess diabetic peripheral neuropathy, in addition to analysis of clinical and epidemiological associated characteristics. RESULTS: We included 116 patients and diabetic peripheral neuropathy was found in 31.9%. There was significant correlation diabetic peripheral neuropathy with age, but not with other clinical and laboratory variables. The mean age was 55±15 years, diabetes duration was 14.8±10.9 years and patients were predominantly Caucasian, women and had type 2 diabetes mellitus. Of the patients, 67.2 % were hypertensive and 42.2% obese. CONCLUSION: The prevalence found is supported by previous data, although few studies have used similar criteria to diagnose diabetic peripheral neuropathy. Employing the standard scores, of low cost and easy implementation, we enable early and accurate diagnosis of this condition, allowing to reduce the prevalence of severe diabetic foot complications and spread information about it.

Fetal pancreas transplants are dependent on prolactin for their development and prevent type 1 diabetes in syngeneic but not allogeneic mice.

Transplantation of adult pancreatic islets has been proposed to cure type 1 diabetes (T1D). However, it is rarely considered in the clinic because of its transient effect on disease, the paucity of donors, and the requirement for strong immunosuppressive treatment to prevent allogeneic graft rejection. Transplantation of fetal pancreases (FPs) may constitute an attractive alternative because of potential abundant donor sources, possible long-term effects due to the presence of stem cells maintaining tissue integrity, and their supposed low immunogenicity. In this work, we studied the capacity of early FPs from mouse embryos to develop into functional pancreatic islets producing insulin after transplantation in syngeneic and allogeneic recipients. We found that as few as two FPs were sufficient to control T1D in syngeneic mice. Surprisingly, their development into insulin-producing cells was significantly delayed in male compared with female recipients, which may be explained by lower levels of prolactin in males. Finally, allogeneic FPs were rapidly rejected, even in the context of minor histocompatibility disparities, with massive graft infiltration with T and myeloid cells. This work suggests that FP transplantation as a therapeutic option of T1D needs to be further assessed and would require immunosuppressive treatment.

Physiopathology of fatigue in multiple sclerosis.

Fatigue is an overwhelming sense of tiredness or lack of energy, affecting both mental and physical domains. Fatigue is reported by about 50% of patients with multiple sclerosis (MS), and may be independent from depressed mood or weakness. Recently, the importance of distinguishing between subjective complaint and objective signs of fatigue has been emphasized, since the self-reported increase of subjective cognitive fatigue may not be related to a decline of cognitive performances. There is a general consensus that fatigue in MS is a central phenomenon, related to several factors. Neurophysiological studies revealed an impairment of volitional drive to the descending motor pathways and functional imaging studies indicated a selective involvement of frontal cortex and basal ganglia. Thus, the physiopathology of fatigue may rely on dysfunction of circuits involving thalamus, basal ganglia, and frontal cortex, which, affected by the MS lesions or disturbed in their function by the products of inflammation, could be the substrate of fatigue. The abnormal subjective fatigue observed in MS and perhaps in other neurological disorders could be due to a higher brain working load required to perform a given mental or physical activity, or to an internal overestimation of such load.

Delivery of the bacterial nitroreductase gene into endothelial cells prolongs the survival of tumour-bearing mice by bystander mechanisms.

A current target of cancer gene therapy is tumour vasculature. We present a gene-directed enzyme prodrug therapy (GDEPT) approach to target tumours in vivo by modifying endothelial cells (ECs) with the Escherichia coli nitroreductase (ntr) gene. Firstly, we isolated two ntr-transfected clones of the human umbilical vein endothelial cell line (HUV-EC-C/ntr+) that showed a differential sensitivity in vitro to the prodrug, dinitroaziridinylbenzamide (CB1954), with respect to untransfected HUV-EC-C cells (HUV-EC-C/ntr-). Then, these cells were injected subcutaneously into nude mice, either in association with the murine melanoma cell line, B16-F10 ('co-injected' groups), or into tumour-bearing animals ('post-injected' groups). After intratumoural injection, we demonstrated, using PCR analysis, that human ECs resided in the site of the injection without spreading to other organs, such as the liver or lung. After the treatment of mice with CB1954, we observed a prolonged survival of animals carrying the HUV-EC-C/ntr+ clones with respect to control animals injected with HUV-EC-C/ntr- cells. Significant differences in tumour growth were also observed and, after immuno-histological analysis, tumours carrying HUV-EC-C/ntr+ clones showed large areas of tumour necrosis, probably due to tumour ischemia, as well as the presence of major histocompatibility complex class-II (MHC-II) positive cells. Collectively, our data indicate that targeting of the tumour vasculature by this GDEPT strategy may be an efficient approach for cancer treatment in vivo, depending on two possible bystander mechanisms based on tumour ischemia and immune cell activation.

Anti-angiogenic strategies for cancer therapy (Review).

Acquired drug resistance to chemotherapy is a major problem in the treatment of cancer. After primary surgical intervention, followed by chemotherapy treatments, the majority of patients develop disease recurrence. This is due to tumor cell heterogeneity and genetic instability. In contrast to tumor cells, proliferating host endothelial cells (ECs) are genetically stable and have a low mutational rate. Furthermore, tumor angiogenesis plays an important role in tumor development, vascular invasion and hematogenous metastasis. Thus, anti-angiogenic therapy directed against tumor ECs should, in principle, improve the efficacy of antitumor therapy by inducing little or no drug resistance. We review different therapeutic approaches directed against tumor angiogenesis, showing potent antitumor activity in vitro and in vivo. These strategies involve the inhibition of the expression of proangiogenic molecules, as well as the overexpression of anti-angiogenic molecules by either injection of recombinant proteins or transfer of genes encoding anti-angiogenic molecules. The gene therapy approach based on the gene-directed enzyme prodrug therapy (GDEPT) system, as well as the use of endothelial progenitor cells (EPCs) as angiogenesis-selective gene-targeting vectors, will be further discussed.

Bystander cell killing spreading from endothelial to tumor cells in a three-dimensional multicellular nodule model after Escherichia coli nitroreductase gene delivery.

Tumor cells are elusive targets for standard anticancer chemotherapy due to their heterogeneity and genetic instability. On the other hand, proliferating host endothelial cells (ECs) are genetically stable and have a low mutational rate. Thus, antiangiogenic therapy directed against tumor's ECs should, in principle, improve the efficacy of antitumor therapy by inducing little or no drug resistance. Here we present a gene-directed enzyme prodrug therapy (GDEPT) strategy for targeting the tumor vasculature, using the Escherichia coli nitroreductase (ntr) gene delivery associated with the treatment with the prodrug CB1954. In a first time we demonstrated the ability of the ntr/CB1954 system to induce an apoptotic-mediated cell death on monolayer cultures of human umbilical vein ECs (HUV-EC-C). Then, when ntr-transfected HUV-EC-C cells (HUV-EC-C/ntr(+)) were associated in a three-dimensional (3-D) multicellular nodule model with untransfected B16-F10 murine melanoma cell line, we observed a CB1954-mediated bystander cell killing effect from endothelial to neighboring melanoma cells. To our knowledge, this is the first report indicating that GDEPT-based antiangiogenic targeting may be an effective approach for cancer treatment relied on the spreading of the bystander effect from endothelial to tumor cells.

Similar immune responses and antitumor effects of murine dendritic cells loaded with either exogenous or endogenous-synthesized protein.

Conceptually, dendritic cells (DCs) take up and process exogenous antigens that are presented on MHC (major histocompatibility complex) class II molecules to stimulate CD4+ T cells, and present endogenously-produced proteins to CD8+ T cells through an MHC class I-dependent pathway. In this study, we compared the antitumor effects generated in vivo after vaccinations with DCs either loaded with exogenous protein (DCs-exo) or presenting antigens derived from endogenous-synthesized protein (DCs-endo). We used the murine MC26SC31 colon carcinoma cell line expressing on the cell surface the human CD4 (hCD4) molecule as a model tumor-associated antigen (TAA). Bone marrow (BM)-derived DCs-endo were obtained from histocompatible transgenic mice constitutively expressing hCD4; BM-derived DCs-exo were obtained after in vitro loading DCs, from syngenic normal mice, with purified soluble hCD4 protein (shCD4). Altogether, our results show that intravenous (i.v.) administration of DCs-exo and DCs-endo can trigger similar cytotoxic and humoral protecting immune responses against a lethal tumor challenge. hCD4 antigen-specific T cell-mediated cytotoxic immune response was not accompanied by elevated INF-gamma serum levels. This suggests, in the case of DCs-exo, a possible in vivo CTL cross-priming triggering a CD8+ T cell-mediated immune response in the absence of de novo antigen synthesis within the DCs.

Aponecrotic, antiangiogenic and antiproliferative effects of a novel dextran derivative on breast cancer growth in vitro and in vivo.

1. Since the sodium phenylacetate (NaPa) was reported to enhance the inhibitory effect of carboxymethyl benzylamide dextran (CMDB) on the breast cancer growth, we performed the esterification of CMDB with NaPa to obtain a new drug carrying the characteristics of these two components. A new molecule, phenylacetate carboxymethyl benzylamide dextran, was named NaPaC. 2. We investigated in vitro and in vivo the effects of NaPaC on MCF-7ras cell growth as well as its apoptotic and antiangiogenic effects in comparison to NaPa and CMDB. In addition, we assessed in vitro the antiproliferative effects of these drugs on other breast cancer cells, including MDA-MB-231, MDA-MB-435 and MCF-7. 3. In vitro, NaPaC inhibited MCF-7ras cell proliferation by 40% at concentration lower than that of CMDB and NaPa (12 microM vs 73 microM and 10 mM). IC(50)s were 6 and 28 microM for NaPaC and CMDB, respectively. The similar results were obtained for three other breast cancer cell lines. NaPaC reduced the DNA replication and induced cell recruitment in G(0)/G(1) phase more efficiently than its components. Moreover, it induced a cell death at concentration 1000-fold lower than NaPa. 4. In vivo, CMDB (150 mg kg(-1)) and NaPa (40 mg kg(-1)) inhibited the MCF-7ras tumour growth by 37 and 57%, respectively, whereas NaPaC (15 mg kg(-1)) decreased tumour growth by 66% without toxicity. 5. NaPa or CMDB reduced the microvessel number in tumour by 50% after 7 weeks of treatment. NaPaC had the same effect after only 2 weeks. After 7 weeks, it generated a large necrosis area without detectable microvessels. In vitro, NaPaC inhibited human endothelial cell proliferation more efficiently than CMDB or NaPa. NaPaC interacts with vascular endothelial growth factor as observed by affinity electrophoresis. 6. NaPaC acts like NaPa and CMDB but in more potent manner than components used separately. Its antiproliferative, aponecrotic and anti-angiogenic actions make it a good candidate for a new anti-cancer drug.