LSD1 is an environmental stress-sensitive negative modulator of the glutamatergic synapse

Along with neuronal mechanisms devoted to memory consolidation –including long term potentiation of synaptic strength as prominent electrophysiological correlate, and inherent dendritic spines stabilization as structural counterpart– negative control of memory formation and synaptic plasticity has been described at the molecular and behavioral level. Within this work, we report a role for the epigenetic corepressor Lysine Specific Demethylase 1 (LSD1) as a negative neuroplastic factor whose stress-enhanced activity may participate in coping with adverse experiences. Constitutively increasing LSD1 activity via knocking out its dominant negative splicing isoform neuroLSD1 (neuroLSD1^KO mice), we observed extensive structural, functional and behavioral signs of excitatory decay, including disrupted memory consolidation. A similar LSD1 increase, obtained with acute antisense oligonucleotide-mediated neuroLSD1 splicing knock down in primary neuronal cultures, dampens spontaneous glutamatergic transmission, reducing mEPSCs. Remarkably, LSD1 physiological increase occurs in response to psychosocial stress-induced glutamatergic signaling. Since this mechanism entails neuroLSD1 splicing downregulation, we conclude that LSD1/neuroLSD1 ratio modulation in the hippocampus is instrumental to a negative homeostatic feedback, restraining glutamatergic neuroplasticity in response to glutamate. The active process of forgetting provides memories with salience. With our work, we propose that softening memory traces of adversities could further represent a stress-coping process in which LSD1/neuroLSD1 ratio modulation may help preserving healthy emotional references.

Irinotecan and temozolomide in recurrent Ewing sarcoma: an analysis in 51 adult and pediatric patients

BACKGROUND

Data on temozolomide (TEM) and irinotecan (IRI) activity in recurrent Ewing sarcoma (EWS), especially in adult patients, are limited.

METHODS

Patients receiving TEM 100 mg/m²/day oral, and IRI 40 mg/m²/day intravenous, days 1-5, every 21 days, were included in this multi-institutional retrospective study. Disease control rate (DCR) [overall response rate (ORR) [complete response (CR) + partial response (PR)] + stable disease (SD)], 6-months progression-free survival (6-mos PFS) and 1-year overall survival (OS) were assessed.

RESULTS

The median age of the 51 patients was 21 years (range 3-65 years): 34 patients (66%) were adults (≥18 years of age), 24 (48%) had ECOG 1 and 35 (69%) were presented with multiple site recurrence. TEMIRI was used at first relapse/progression in 13 (25%) patients, while the remainder received TEMIRI for second or greater relapse/progression. Fourteen (27%) patients had received prior myeloablative therapy with busulfan and melphalan. We observed five (10%) CR, 12 (24%) PR and 19 (37%) SD, with a DCR of 71%. 6-mos PFS was 49% (95% CI 35-63) and it was significantly influenced by ECOG (6-mos PFS 64% [95% CI 45-83] for ECOG 0, 34% [95% CI 14-54] for ECOG ≥1; p = .006) and LDH (6-mos PFS 62% [95% CI 44-79] for normal LDH, 22% [95% CI 3-42] for high LDH; p = .02), with no difference according to line of treatment, age and metastatic pattern. One-year OS was 55% (95% CI 39-70), with RECIST response (p = .001) and ECOG (p = .0002) independently associated with outcome. Grade 3 and 4 toxicity included neutropenia in 12% of patients, thrombocytopenia in 4%, diarrhea in 4%.

CONCLUSIONS

This series confirms the activity of TEMIRI in both adults and pediatric patients. This schedule offers a 71% DCR, independently of the line of chemotherapy. Predictive factors of response are ECOG and LDH.

Transcriptomic analysis and mutational status of IDH1 in paired primary-recurrent intrahepatic cholangiocarcinoma

Background

Effective target therapies for intrahepatic cholangiocarcinoma (ICC) have not been identified so far. One of the reasons may be the genetic evolution from primary (PR) to recurrent (REC) tumors. We aim to identify peculiar characteristics and to select potential targets specific for recurrent tumors.

Eighteen ICC paired PR and REC tumors were collected from 5 Italian Centers. Eleven pairs were analyzed for gene expression profiling and 16 for mutational status of IDH1. For one pair, deep mutational analysis by Next Generation Sequencing was also carried out. An independent cohort of patients was used for validation.

Results

Two class-paired comparison yielded 315 differentially expressed genes between REC and PR tumors. Up-regulated genes in RECs are involved in RNA/DNA processing, cell cycle, epithelial to mesenchymal transition (EMT), resistance to apoptosis, and cytoskeleton remodeling. Down-regulated genes participate to epithelial cell differentiation, proteolysis, apoptotic, immune response, and inflammatory processes. A 24 gene signature is able to discriminate RECs from PRs in an independent cohort; FANCG is statistically associated with survival in the chol-TCGA dataset. IDH1 was mutated in the RECs of five patients; 4 of them displayed the mutation only in RECs. Deep sequencing performed in one patient confirmed the IDH1 mutation in REC.

Conclusions

RECs are enriched for genes involved in EMT, resistance to apoptosis, and cytoskeleton remodeling. Key players of these pathways might be considered druggable targets in RECs. IDH1 is mutated in 30% of RECs, becoming both a marker of progression and a target for therapy.

Electronic supplementary material

The online version of this article (10.1186/s12864-018-4829-0) contains supplementary material, which is available to authorized users.

A new Procedure for Large Scale Production and Freezing of Lymphokine Activated Killer (LAK) Cells to be used in Adoptive Immunotherapy of Cancer

A new procedure for activation of peripheral blood lymphocytes (PBL) with recombinant interleukin 2 (rIL2) is described. PBL obtained by leukapheresis were subjected to NH4Cl (ACK) treatment to clear erythrocyte contamination; Ficoll separation was not performed. PBL were subsequently seeded in 10-floor multitrays (Cell Factory™, CF), gasified and incubated at 37 °C for 3-4 days in a humidified 5% CO2 atmosphere. This procedure achieved an activation (evaluated as cytotoxicity and proliferation) comparable with that obtained by culturing PBL in small flasks. Optimal activation of PBL was achieved in CF even in the presence of granulocyte contamination of up to 40%. It was also possible to freeze, thaw and recover most of the frozen cells and their cytotoxic activity. With this procedure therefore large quantities of lymphokine activated killer cells (LAK) can be easily produced to be used in adoptive immunotherapy trials.

New European Clinical Trial Regulation: perception and expectations in Italy

Background

In July 2012, the European Commission formalized the proposal for a European Clinical Trial Regulation that should replace the European Clinical Trials Directive 2001/20/CE. The new Regulation 536/2014 entered into force in June 2014 and it was expected to be applied not earlier than May 2016. Indeed, at the time, all required central tools are not yet available and new forecasts indicate it will become effective at the end of 2018. The aims of the Regulation are the promotion of higher standards in patient's safety and increasing transparency in Clinical Trials, also by changing the application process.

Methods

An online survey was conducted among the Italian's Clinical Research Coordinators and Clinical Investigators to examine the perception and knowledge about the upcoming changes in Clinical Trials. A total of 190 Clinical Research Coordinators and 80 Clinical Investigators were surveyed.

Results

Clinicians are less aware of the content of the Regulation than Clinical Research Coordinators, who demonstrate an extensive expertise on the topic (84.4%), mainly reached through self-training. The majority of the Investigators (74%) believes that their site's facilities and staff already met all the requirements imposed by the Regulation while Clinical Research Coordinators are less optimistic: 65.2% of them believes that the site staff is not yet fully aware of changes associated to its implementation.

Conclusions

The general opinion of the interviewed is that the new Regulation will strongly affect the trial management regardless of their type and phase, and the fulfillment of the imposed requirements represents an opportunity that Italy should not miss to increase its attractiveness to the pharmaceutical market.

Denosumab in advanced/unresectable giant-cell tumour of bone (GCTB): For how long?

BACKGROUND

Giant-cell tumours of bone (GCTB) are RANK/RANK-ligand (RANKL) positive, aggressive and progressive osteolytic tumours. Denosumab, a RANKL inhibitor, was FDA-approved for adults and skeletally mature adolescents with unresectable GCTB or when surgical resection is likely to result in severe morbidity. Data on long-term toxicity and activity of denosumab monthly 'GCTB-schedule' (120 mg per 12/year, 1440 mg total dose/year) are lacking.

METHODS

Patients with GCTB receiving denosumab, 120 mg on days 1, 8, 15, 29 and every 4 weeks thereafter, from 2006 to 2015 treated in two centres were included. Long-term toxicity was evaluated.

RESULTS

Ninety-seven patients were identified. 43 patients underwent resection of the tumour with a median time on denosumab treatment of 12 months (range 6-45 months). Fifty-four patients had unresectable GCTB's (male/female 23/31, median age 35 years [range: 13-76 years], 26% presented with lung metastases, 31% had primary tumor located to the spine, 63% were relapsed after previous surgery) with a median time on denosumab of 54 months (9-115 months). In the unresectable GCTB group, tumour control and clinical benefits were observed in all patients undergoing denosumab, whereas 40% of patients discontinuing denosumab had tumour progression after a median of 8 months (range 7-15 months).

ADVERSE EVENTS

Overall, six (6%) patients developed osteonecrosis of jaw (ONJ): 1/43 (2%) in the resectable group, 5/54 (9%) in the unresectable group, with a 5-year ONJ-free survival of 92% (95% CI 84-100). Only patients with prolonged treatment experienced mild peripheral neuropathy (6/54, 11%), skin rash (5/54, 9%), hypophosphataemia (2/54, 4%) and atypical femoral fracture (2/54, 4%).

CONCLUSIONS

Prolonged treatment with denosumab has sustained activity in GCTB, with a mild toxicity profile. The dose-dependent toxicity observed recommends a careful and strict monitoring of patients who need prolonged treatment. Decreased dose-intensity schedules should be further explored in unresectable GCTB.

Gemcitabine and docetaxel in relapsed and unresectable high-grade osteosarcoma and spindle cell sarcoma of bone

BACKGROUND

Few new compounds are available for relapsed osteosarcoma. We retrospectively evaluated the activity of gemcitabine (G) plus docetaxel (D) in patients with relapsed high-grade osteosarcoma and high-grade spindle cell sarcoma of bone (HGS).

METHODS

Patients receiving G 900 mg/m(2) d 1, 8; D 75 mg/m(2) d 8, every 21 days were eligible. Primary end-point: progression-free survival (PFS) at 4 months; secondary end-point: overall survival (OS) and response rate.

RESULTS

Fifty-one patients were included, with a median age of 17 years (8-71), 26 (51%) were pediatric patients. GD line of treatment: 2nd in 14 patients, ≥3rd in 37. 25 (49%) patients had metastases limited to lungs, 26 (51%) multiple sites.

HISTOLOGY

40 (78%) osteosarcoma, 11 (22%) HGS. Eight (16%) patients achieved surgical complete response (sCR2) after GD. Four-month PFS rate was 46%, and significantly better for patients with ECOG 0 (ECOG 0: 54% vs ECOG 1: 43% vs ECOG 2: 0%; p = 0.003), for patients undergoing metastasectomy after GD (sCR2 75% vs no-sCR2 40 %, p = 0.02) and for osteosarcoma (osteosarcoma 56% vs HGS 18%; p = 0.05), with no differences according to age, line of treatment, and pattern of metastases. Forty-six cases had RECIST measurable disease: 6 (13%) patients had a partial response (PR), 20 (43%) had stable disease (SD) and 20 (43%) had progressive disease (PD). The 1-year OS was 30%: 67% for PR, 54% for SD and 20% for PD (p = 0.005).

CONCLUSIONS

GD is an active treatment for relapsed high-grade osteosarcoma, especially for ECOG 0 patients, and should be included in the therapeutic armamentarium of metastatic osteosarcoma.

Listeria Monocytogenes: an uncommon pathogen of cervical necrotizing fasciitis

The aim of this paper is to present a unique case of neck-necrotizing fasciitis caused by Listeria Monocytogenes in a young woman, successfully treated by surgery and IV antibiotic therapy. Necrotizing fasciitis is a rare, rapidly progressing and potentially life-threatening infection that infrequently occurs in the head and neck region. Pathogens involved in necrotizing fasciitis are heterogeneous and include aerobic and anaerobic bacteria. To the best of our knowledge, this is the only case of neck necrotizing fasciitis caused by Listeria Monocytogenes studied in literature so far.

Improved aetiological diagnosis of ischaemic stroke in a Vascular Medicine Unit--the significance of transesophageal echocardiogram

BACKGROUND

The TOAST study estimates that 34% of ischaemic strokes are of undetermined aetiology. Improvements in the diagnosis of the pathogenetic mechanism of ischaemic stroke would translate into a better care, in analogy to other fields of vascular and internal medicine.

OBJECTIVE

To measure the reduction of undetermined aetiology strokes performing a set of additional diagnostic tests.

DESIGN

Consecutive case series with historical controls.

SETTING

Internal Medicine Ward with a stroke area (SA) admitting most stroke patients of a large hospital in Italy.

SUBJECTS

A total of 179 ischaemic stroke patients admitted to SA in 2004-2005 compared with 105 ischaemic stroke patients admitted to the whole department in 2001.

INTERVENTION

To perform more diagnostic tests, including transesophageal echocardiography (TEE), in the greatest possible number of ischaemic stroke inpatients admitted in SA of the Internal Medicine Department, in the years 2004-2005.

RESULTS

More diagnostic tests were performed during the study period than in 2001, especially TEE (56% of patients in 2004-2005 vs. 3% of patients in 2001). We observed a significant reduction of undetermined aetiology from 38% in 2001 to 16% in 2004-2005 (p < 0.0001), largely for an increased identification of cases of cardio-embolic mechanism (from 18% to 40%, p = 0.0002). In the years 2004-2005 the fraction of patients on anticoagulant treatment at discharge was 21% vs. 12% in 2001 (p = 0.041).

CONCLUSION

Performing more tests, particularly TEE, brought improvements in the aetiological diagnosis of stroke, increasing cardio-embolism diagnosis and anticoagulant treatment.

Inhibition of promyelocytic leukemia (PML)/retinoic acid receptor-alpha and PML expression in acute promyelocytic leukemia cells by anti-PML peptide nucleic acid

The fusion protein promyelocytic leukemia (PML)/retinoic acid receptor (RAR)alpha is tightly linked to the pathogenesis of acute promyelocytic leukemia (APL); hence, it represents a tumor-associated, transformation-related molecule. In this study, three anti-PML adamantyl-conjugated peptide nucleic acid (PNA) oligomers previously described as in vitro inhibitors of PML/RARalpha translation were combined and used to block PML/RARalpha synthesis in NB4 cells. Cationic liposomes were used to achieve sufficient delivery of PNAs into the cells. Upon treatment of cells with the liposome/PNA mixture, enhanced cellular uptake of PNA (approximately 5-fold compared with control) was obtained. Concomitantly, a substantial reduction (>90%) of the expression of PML/RARalpha was observed when all of the three PNAs were used together. This resulted in a dramatic effect on the number and viability of NB4 cells in culture after 48 h of treatment. This phenomenon was preceded by induction of apoptosis that could be observed 24 h after treatment. No sign of granulocytic differentiation was observed after treatment. These effects were also noted on other leukemic cell lines that express PML but not the fusion transcript. These results show that it is possible to deliver PNA into hematopoietic cells and obtain specific gene inhibition, and they suggest that a growth inhibitory effect on acute promyelocytic leukemia cells can be obtained through the block of PML/RARalpha and PML expression.

Sensitivity to the abl inhibitor STI571 in fresh leukaemic cells obtained from chronic myelogenous leukaemia patients in different stages of disease

STI571 (CGP57148B) is an inhibitor of BCR/ABL, the cause of chronic myeloid leukaemia (CML). A difference exists between CML patients in chronic phase, in which responses to STI571are durable, and patients in blast crisis, who generally experience only transient responses. Leukaemic cells from six CML patients from whom samples could be obtained during chronic phase and at the time of blast crisis (BC) were compared for sensitivity to STI571, using an in vitro assay. BC samples showed a sensitivity similar to that obtained during chronic phase, suggesting that no substantial intrinsic resistance to STI571 was present in BC.

Differential recognition of a BCR/ABL peptide by lymphocytes from normal donors and chronic myeloid leukemia patients

The BCR/ABL oncogenic fusion protein transforms normal bone marrow stem cells into neoplastic cells. It has been shown that peptides derived from the junctional region of this oncogenic fusion protein can be recognized by human T-lymphocytes obtained from normal donors. In this study, we investigated the immunogenicity in patients with chronic myeloid leukemia (CML) of a 17 mer b3/a2 Bcr/abl peptide (B/A1), which was shown to induce proliferative responses in lymphocytes from normal donors. A total of 56 CML patients in chronic phase were studied. Twenty-two patients were studied at diagnosis without any treatment (group I). Fourteen patients were receiving IFN (group II), 14 patients were being treated with hydroxyurea (group III), and 6 patients were on different regimens (group IV). Patients were initially assessed for general immunological competence using both in vivo and in vitro assays. Patients were also selected for the expression of HLA-DR0401, the HLA specificity known to present peptide B/A1 to CD4 lymphocytes. With the exception of the six patients in group IV, the results of all these assays (in vitro phytohemagglutinin/tetanus toxoid responses, in vivo skin reaction to ubiquitous antigens) in CML patients did not significantly differ from those obtained in normal donors, thus excluding the presence of generalized immunosuppression. Eight patients with HLA-DR0401 and a b3/a2 type of fusion were identified and further studied. In these eight patients dendritic cells were obtained from adherent peripheral blood mononuclear cells and used to stimulate CD4 lymphocytes. No patient developed a specific response to the bcr/abl peptide, although patients' lymphocytes proliferated in response to a promiscuous tetanus toxoid peptide in all but one case. In contrast, response to the bcr/abl peptide was observed in seven of eight HLA-DR0401 healthy donors tested. These data suggest that immunocompetent, HLA-DR0401+ CML patients are unable to respond to peptide B/A1, at difference from healthy donors. The implication of these results for the immunotherapy of CML is discussed.

Induction of resistance to the Abelson inhibitor STI571 in human leukemic cells through gene amplification

The 2-phenylaminopyrimidine derivative STI571 has been shown to selectively inhibit the tyrosine kinase domain of the oncogenic bcr/abl fusion protein. The activity of this inhibitor has been demonstrated so far both in vitro with bcr/abl expressing cells derived from leukemic patients, and in vivo on nude mice inoculated with bcr/abl positive cells. Yet, no information is available on whether leukemic cells can develop resistance to bcr/abl inhibition. The human bcr/abl expressing cell line LAMA84 was cultured with increasing concentrations of STI571. After approximately 6 months of culture, a new cell line was obtained and named LAMA84R. This newly selected cell line showed an IC50 for the STI571 (1.0 microM) 10-fold higher than the IC50 (0.1 microM) of the parental sensitive cell line. Treatment with STI571 was shown to increase both the early and late apoptotic fraction in LAMA84 but not in LAMA84R. The induction of apoptosis in LAMA84 was associated with the activation of caspase 3-like activity, which did not develop in the resistant LAMA84R cell line. LAMA84R cells showed increased levels of bcr/abl protein and mRNA when compared to LAMA84 cells. FISH analysis with BCR- and ABL-specific probes in LAMA84R cells revealed the presence of a marker chromosome containing approximately 13 to 14 copies of the BCR/ABL gene. Thus, overexpression of the Bcr/Abl protein mediated through gene amplification is associated with and probably determines resistance of human leukemic cells to STI571 in vitro. (Blood. 2000;95:1758-1766)

Plasminogen activator inhibitor-1 and carotid intima-media thickening in patients with newly detected primary hypertension

OBJECTIVE

To investigate the correlation between ultrasonographically evaluated intima-media thickness (IMT) of common carotid artery (CCA) and cardiovascular risk factors for subjects with newly detected, uncomplicated and untreated primary hypertension.

METHODS

The study population consisted of 200 subjects (123 men and 77 women, aged 46+/-7.5 years). Blood pressure was measured in the clinical setting and by 24 h noninvasive ambulatory monitoring. Fasting levels of blood glucose, plasma lipids and lipoproteins, fibrinogen and plasminogen activator inhibitor (PAI)-1 were measured. Ultrasound examination included measurement of far-wall intima-media complex of CCA and morphologic evaluation of occurrence of plaques in carotid and femoral bifurcations.

RESULTS

The prevalence of greater than normal IMT (mean IMT > or =0.80 mm) was 22%. Significant univariate correlations to the dichotomy between normal and greater than normal mean IMT were detected for age, smoking, level of LDL cholesterol, level of PAI-1 and total ultrasonographic score. Multivariate logistic regression analysis confirmed the associations between greater than normal mean IMT and plasma concentrations of LDL cholesterol and PAI-1 as well as total ultrasonographic score.

CONCLUSION

Greater than normal IMT of CCA was more strictly related to other cardiovascular risk factors than it was to blood pressure and was strongly associated with the occurrence of atherosclerotic plaques in carotid and femoral arteries. The role of PAI-1 in intima-media thickening that is emerging suggests that fibrinolytic balance is an important determinant of vessel-wall homeostasis in hypertensive patients.

The nature of prooxidant activity of vitamin C

It was recently reported that vitamin C (500 mg/day for 6 weeks) administered as a dietary supplement to healthy humans exhibits a prooxidant, as well as an antioxidant effect in vivo. Here we show that high intakes of vitamin C (500 mg/kg b.w. for 4 days) in the rat are able to markedly induce hepatic cytochrome P4502E1-linked monooxygenases, measured as p-nitrophenol hydroxylase activity and corroborated by means of Western blot analyses. Furthermore, using Electron Paramagnetic Resonance Spectroscopy (EPR) coupled to a spin-trapping technique, we have also found that this induction generates large amounts of the anion radical superoxide (O2-). Therefore we can conclude that the adverse prooxidant outcomes (i.e. oxidative DNA damage) associated to vitamin C supplementation, being associated to a typical reversible boosting effect (i.e. enzymatic induction), may be easily controlled by a discontinuous supply. However, since the induced P4502E1 isoforms by vitamin C are responsible for ethanol metabolism to highly reactive radicals, care should be taken even in moderate drinkers.

Three groups of species in Petunia sensu Jussieu (Solanaceae) inferred from the intact seed

The intact seed surface morphology in 45 taxa of Petunia sensu Jussieu native to South America (Petunia sensu Wijsman plus Calibrachoa) was compared under scanning electron microscopy. The existence of three groups of species, differentiated in terms of seed morphology, was revealed as follows: (1) all species of Petunia sensu Wijsman, having coarse wavy middle lamellae and anticlinal walls; (2) Calibrachoa parviflora and C. pygmaea, having fine wavy middle lamellae embedded in straight anticlinal walls; and (3) the other species of Calibrachoa, having straight middle lamellae and anticlinal walls. Close relationships between seed morphology and the other characteristics observable in the groups of species are discussed.

Medium effects on the antioxidant activity of dipyridamole

Very strong medium effects have been observed when testing the antioxidant activity of dipyridamole (DP) in different media such as benzene, tert-butanol, methanol solutions and egg yolk lecithin unilamellar and multilamellar vesicles. Actually, dipyridamole behaves as a very poor antioxidant in benzene while its ability to inhibit the lipid peroxidation reaction increases with increasing solvent polarity, being the highest in lipid vesicles. This behavior can not be rationalized on the basis of the classical chain breaking mechanism which operates in the case of phenolic and amine antioxidants and involving the transfer of a hydrogen atom to peroxyl radicals. An explanation is instead given in terms of an electron transfer reaction which leads to the oxidation of DP by the chain carrying peroxyl radical to give the dipyridamole cation radical, DP+*, and the peroxyl anion LOO-, and whose rate constant is expected to increase in strongly polar media. EPR and electrochemical data supporting this interpretation have been collected.

In vivo eradication of human BCR/ABL-positive leukemia cells with an ABL kinase inhibitor

BACKGROUND

The leukemia cells of approximately 95% of patients with chronic myeloid leukemia and 30%-50% of adult patients with acute lymphoblastic leukemia express the Bcr/Abl oncoprotein, which is the product of a fusion gene created by a chromosomal translocation [(9:22) (q34;q11)]. This oncoprotein expresses a constitutive tyrosine kinase activity that is crucial for its cellular transforming activity. In this study, we evaluated the antineoplastic activity of CGP57148B, which is a competitive inhibitor of the Bcr/Abl tyrosine kinase.

METHODS

Nude mice were given an injection of the Bcr/Abl-positive human leukemia cell lines KU812 or MC3. Tumor-bearing mice were treated intraperitoneally or orally with CGP57148B according to three different schedules. In vitro drug wash-out experiments and in vivo molecular pharmacokinetic experiments were performed to optimize the in vivo treatment schedule.

RESULTS

Treatment schedules administering CGP57148B once or twice per day produced some inhibition of tumor growth, but no tumor-bearing mouse was cured. A single administration of CGP57148B caused substantial (>50%) but short-lived (2-5 hours) inhibition of Bcr/Abl kinase activity. On the basis of the results from in vitro wash-out experiments, 20-21 hours was defined as the duration of continuous exposure needed to block cell proliferation and to induce apoptosis in these two leukemia cell lines. A treatment regimen assuring the continuous block of the Bcr/Abl phosphorylating activity that was administered over an 11-day period cured 87%-100% of treated mice.

CONCLUSION

These data indicate that the continuous block of the oncogenic tyrosine kinase of Bcr/Abl protein is needed to produce important biologic effects in vivo.

Photoreduction of the fluorescent dye 2'-7'-dichlorofluorescein: a spin trapping and direct electron spin resonance study with implications for oxidative stress measurements

The photoreduction of 2'-7'-dichlorofluorescein (DCF) was investigated in buffer solution using direct electron spin resonance (ESR) and the ESR spin-trapping technique. Anaerobic studies of the reaction of DCF in the presence of reducing agents demonstrated that during visible irradiation (lambda > 300 nm) 2'-7'-dichlorofluorescein undergoes one-electron reduction to produce a semiquinone-type free radical as demonstrated by direct ESR. Spin-trapping studies of incubations containing DCF, 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and either reduced glutathione (GSH) or reduced NADH demonstrate, under irradiation with visible light, the production of the superoxide dismutase-sensitive DMPO/*OOH adduct. In the absence of DMPO, measurements with a Clark-type oxygen electrode show that molecular oxygen is consumed in a light-dependent process. The semiquinone radical of DCF, when formed in an aerobic system, is immediately oxidized by oxygen, which regenerates the dye and forms superoxide.

Inhibition of the ABL kinase activity blocks the proliferation of BCR/ABL+ leukemic cells and induces apoptosis

The BCR/ABL fusion protein transforms myeloid stem cells. Both chronic myelogenous leukemias (CML) and a subset of acute lymphoblastic leukemias (ALL) are associated with the expression of BCR/ABL proteins. This knowledge has not yet been translated into any specific tool to control ABL driven neoplastic cells growth. CGP57148B is an ATP-competitive inhibitor of the ABL protein kinase; it has been shown to inhibit the kinase activity of ABL both in vitro and in vivo and to inhibit the growth of v-abl and bcr/abl transfectants, as well as the in vitro formation of bone marrow (BM)-derived colonies in the presence of growth factors in some CML patients. These studies were performed to investigate the activity of CGP57148B on the spontaneous proliferation of both fresh and cultured, leukemic and normal, BCR/ABL positive and negative cells, and to study its mechanism of action. Six cell lines derived from BCR/ABL+ leukemias (K562, BV173, KCL22, KU812, MC3, LAMA84), thirteen BCR/ABL negative lines, both neoplastic (KG1, SU-DHL-1, U937, Daudi, NB4, NB4.306) and derived from normal cells (PHA blasts, LAK, fibroblasts, LCL, renal epithelial cells, endothelial cells, CD34(+) cells), and 14 fresh leukemic samples were tested using a tritiated thymidine uptake assay. The in vivo phosphorylation of the BCR/ABL protein was evaluated by western blot, while apoptosis was detected by the annexin V/propidium binding test. The induction of differentiation was assayed by immunofluorescence using multiple antibodies. All six BCR/ABL+ lines showed a dose dependent inhibition of their spontaneous proliferative rate, which was not accompanied by differentiation. The treatment caused, within minutes, dephosphorylation of the BCR/ABL protein, followed in 16-24 hours by a decrease in cycling cells and induction of apoptosis. No significant inhibition of DNA synthesis was observed in any BCR/ABL negative normal or neoplastic line at concentrations </=3 microM, with the exception of fibroblasts and CD34 cells. Proliferation inhibition was observed also when using fresh samples obtained from two Ph+ ALL and 12 consecutive CML patients. Induction of apoptosis was observed in these samples too. The activity of CGP57148B can be monitored in ex vivo isolated or cultured cells using a simple and reproducible assay, without the need for exogenously added growth factors. This molecule possibly exerts its effects through the inhibition of the kinase activity of BCR/ABL and the subsequent initiation of apoptosis, without inducing cell differentiation. Some normal cells are also affected. These data support the use of CGP57148B in initial clinical studies; possible toxic effects on BM and fibroblast-derived cells will have to be closely monitored. The in vivo monitoring of patients will have to be focused on the induction of apoptosis in leukemic cells.

HLA binding characteristics and generation of cytotoxic lymphocytes against peptides derived from oncogenic proteins

AIMS AND BACKGROUND

Structurally altered proteins (derived from chromosomal translocations or gene mutations) can be considered tumor specific antigens and represent an attractive target for a T-cell mediated response. T lymphocytes recognize antigens in the form of peptides bound to HLA-molecules.

MATERIALS AND METHODS

Peptides derived from oncogenic proteins were screened for the presence of HLA binding motifs; actual binding were evaluated by HLA stabilization experiments using transfectants and specific anti-HLA antibodies. Specific lymphocytes were induced by in vitro peptide sensitization and screened by thymidine uptake or cellular cytotoxic assays.

RESULTS

We identified peptides derived from EWS/FLI-1 fusion protein and from mutated K-RAS protein (encompassing respectively the fusion point and the mutation at position 12) that showed binding motif for HLA-Cw*0702 and HLA-A3 respectively. The actual binding of these peptides was analysed in a stabilization assay. We detected binding for the EWS/FLI-1 peptide and for 5 RAS peptides (1 wild type and 4 mutated). The effect of temperature, beta 2-microglobulin (beta 2-m) and fetal calf serum (FCS) on the binding and the stability of the HLA/peptide complex was studied. A low temperature (26 degrees C) increased the binding both in HLA-A3 and HLA-Cw*0702, while FCS reduced it. beta 2-m increased the binding to the HLA-A3 molecule but did not influence the binding to the HLA-Cw*0702. The stability of already formed complexed was somewhat different in the HLA-A3 and HLA-Cw*0702 system: both were more stable at 26 degrees C than at 37 degrees C but while the beta 2-m and FCS did not influence the stability of the HLA-A3/peptide complex, they seemed to cause opposite effects in the HLA-Cw*0702 system (beta 2-m stabilized and FCS destabilized the complex). Finally, we were able to generate a specific CD8+ CTL line against a K-RAS mutated peptide.

CONCLUSIONS

Although binding motifs and actual HLA binding can be detected in several cases, the generation of a cellular response is infrequent, confirming that HLA binding is necessary but not sufficient to obtain an in vitro response. Further optimization of culture conditions, type of Antigen Presenting Cells (APC), peptides, use of stabilizers like beta 2-m are still needed.

Structural changes in the heart and carotid arteries in hypertensive patients associated with cardiovascular risk factors

OBJECTIVE

To estimate the relationship between structural changes in the heart and in the carotid arteries in hypertensives and to analyze the correlations between these structural changes and cardiovascular risk factors.

METHODS

We studied 76 subjects (39 men and 27 women, mean age 45+/-7 years) with mild-to-moderate untreated and uncomplicated hypertension. All of the subjects underwent ambulatory blood pressure monitoring, M-mode echocardiography for evaluation of their left ventricular mass and B-mode high-resolution ultrasonography to determine their carotid arterial wall thickness.

RESULTS

The mean intimal plus medial thickness of the common carotid artery was found to be related significantly and independently to the left ventricular mass indexed by the body surface area. In multivariate analysis, age and the high-density lipoprotein cholesterol level were related strongly to the intimal plus medial thickness, whereas the clinic systolic blood pressure, average night-time systolic blood pressure and glycemia were the most important determinants of the left ventricular mass index. Logistic regression analysis suggested that the thickness of the posterior left ventricular wall was a stronger predictor of the carotid intima-medial thickness than were age and the high-density lipoprotein cholesterol level.

CONCLUSION

The carotid wall thickness and left ventricular mass of hypertensives are related independently; nevertheless the main determinants of structural cardiac and vascular changes are probably different.

Carotid intima-media thickening and in vivo LDL oxidation in patients with essential hypertension

Low density lipoproteins (LDL) from hypertensive patients are more prone to in vitro oxidation and undergo a more pronounced oxidation in vivo. Due to the pro-atherogenic activity of oxidatively modified LDL, the correlation between the carotid intima-media thickening (IMT) and the markers of in vivo LDL oxidation was investigated in hypertensive patients. A cross-sectional study on 101 normocholesterolemic patients with newly diagnosed and untreated essential hypertension was performed. The occurrence of in vivo LDL oxidation was evaluated by measuring the titers of autoantibodies against Cu(2+)-oxidised LDL (oxLDL) and malondialdehyde-derivatised LDL (MDA-LDL). The extent and degree of atherosclerosis and the IMT were measured by means of carotid and femoral ultrasonography with a duplex scanner equipped with a high resolution probe. We did not find significant correlations between in vivo LDL oxidation parameters and the extent of atherosclerotic lesion in the entire group of hypertensive patients. However, a significant direct correlation was detected between the carotid IMT and the titer of autoantibodies against both oxLDL and MDA-LDL in hypertensive patients without advanced atherosclerotic plaques. The results obtained support the hypothesis that enhanced LDL oxidation may be one of the pathophysiological events related to the formation and progression of early atherosclerotic lesions (IMT) in carotid arteries of hypertensive patients.

In vitro transcription and translation inhibition by anti-promyelocytic leukemia (PML)/retinoic acid receptor alpha and anti-PML peptide nucleic acid

Peptide nucleic acids (PNAs) complementary to the 15 bases around the fusion point of both genomic DNA and cDNA of the promyelocytic leukemia/retinoic acid receptor alpha (PML/ RAR alpha; P/R) hybrid gene present in acute promyelocytic leukemia cells were synthesized and shown by gel retardation experiments to specifically bind oligonucleotides corresponding to the fusion region of the P/R molecule. PNA was also able to successfully compete with anti-P/R DNA for duplex formation with P/R DNA and to displace the anti-P/R DNA from dsDNA. In vitro transcribed P/R RNA from two inserts of approximately 350 to approximately 700 bp were tested in gel acceleration experiments with fluorescein-conjugated PNA and showed stable binding (resistant to denaturing conditions) of PNA to the newly transcribed RNA. Control RNA or transcripts from the noncoding strand did not bind PNA. However, this PNA, although able to specifically clamp polymerase chain reaction, was incapable of inhibiting in vitro translation of the PML/RAR alpha mRNA, even when a bis-PNA was used. Therefore, a PNA was targeted against the start region of the P/R cDNA and against poly-purine regions of the gene. Specific inhibition of in vitro translation and transcription was shown, starting at concentrations as low as 100 nmol/L. When oligonucleotides presenting the same sequence were compared, PNA proved to be approximately 40 times more active. In conclusion, in vitro inhibition of translation and transcription of the P/R gene can be obtained with PNA; however, it is still necessary to target the ATG start region or poly-purine regions of the gene.

Protective effects of carvedilol, a vasodilating beta-adrenoceptor blocker, against in vivo low density lipoprotein oxidation in essential hypertension

Low density lipoprotein (LDL) oxidation plays a crucial role in the development and progression of atherosclerosis and is enhanced in patients with essential hypertension. This finding has stimulated a search for antihypertensive drugs with high intrinsic antioxidant properties. We investigated the antihypertensive and antioxidant effects of carvedilol, a new vasodilating beta-adrenoceptor blocking agent in a group of patients with mild to moderate essential hypertension after 4-month treatment. Carvedilol administration markedly increased the resistance to oxidation of LDL isolated from treated patients to values comparable to those of control, nonhypertensive subjects. This effect was achieved despite a significant loss in LDL-associated vitamin E. The increased resistance of LDL to oxidation promoted by carvedilol was not related to the normalization of previously increased blood pressure (BP). Indeed, the administration of other conventional antihypertensive drugs, capable of decreasing arterial BP but without high intrinsic antioxidant properties, to a control group of matched hypertensive patients failed to ameliorate LDL oxidation parameters. Carvedilol treatment also reduced the extent of in vivo LDL oxidation, as reflected by the decrease in antioxidized LDL autoantibody titer. This effect as well was detected only in the group of carvedilol-treated hypertensive patients and not after the simple reduction in BP obtained with antihypertensive drugs different from carvedilol.

Lack of T-cell-mediated recognition of the fusion region of the pml/RAR-alpha hybrid protein by lymphocytes of acute promyelocytic leukemia patients

In previous studies, it was shown that the fusion region of the pml/RAR-alpha protein, expressed by acute promyelocytic leukemia (APL) cells, can be specifically recognized in vitro by donor (D. E. ) CD4 T cells in a HLA class II DR11-restricted fashion. We present here the results on the recognition of several pml/RAR-alpha peptides by APL patients expressing HLA DR11. The in vitro immunization of peripheral blood lymphocytes from four patients in remission (S. R., F. R., M. M., P. G.) with BCR1/25, a 25-mer pml/RAR-alpha, did not elicit either a polyclonal or a clonal immune response specific to the peptide. We then generated new donor anti-pml/RAR-alpha CD4(+) T-cell clones. These clones were tested for their recognition of BCR1/25. One clone (C3/5, CD3(+), CD4(+), CD8(-)) was selected for further analysis. Clone C3/5 showed specific proliferation, cytotoxicity, and cytokine (tumor necrosis factor alpha, granulocyte-macrophage colony-stimulating factor) production when challenged with autologous lymphoblastic cell lines pulsed with peptide BCR1/25. C3/5 cells developed specific proliferation and cytotoxicity when challenged with peptide-pulsed lymphoblastic cell lines and peripheral blood lymphocytes from the four DR11(+) APL patients. APL blasts, available only from patients F. R. and P. G., were not lysed by C3/5 and were unable to present peptide BCR1/25. Incubation of APL cells with IFN-gamma failed to induce HLA class II molecules and recognition by the C3/5 clone. Since APL cells do not express HLA class II molecules, we tested in two donors (D. E. and C. H. R.) and in patients S. R. and P. G. whether the use of 9-mer peptides (BCR1/9) would generate a CD8/HLA class I-restricted response. No peptide-specific T-cell line or clone could be generated from both donors and patients. These findings are discussed in relation to possible therapeutic approaches to the immunotherapy of APL.

Effect of sublingual nifedipine on left ventricular diastolic dysfunction in hypertensives: echo-Doppler study at rest and during handgrip

Using digitized M-mode echocardiography, we evaluated the acute effect of nifedipine on left ventricular (LV) diastolic dysfunction in 30 untreated hypertensives, evaluated at rest and during handgrip, both before and 30' after nifedipine (20 mg sublingually). At rest, after nifedipine blood pressure and end-systolic wall stress significantly decreased and peak lengthening rate of LV diameter, peak thinning rate of LV posterior wall and Doppler E/A ratio increased. Before and after nifedipine handgrip induced significant increases of blood pressure, heart rate and end-systolic wall stress; diastolic parameters significantly decreased during basal handgrip and did not change during handgrip after nifedipine. Nifedipine induced an acute improvement of LV diastolic dysfunction, that persisted when afterload increased during handgrip. Therefore nifedipine seems to improve LV diastolic function not only by reducing afterload, but also through a direct action on the myocardium. Besides, these results demonstrate that LV diastolic abnormalities in hypertension are partly dynamic and reversible.

Demonstrable cardiac reinnervation after human heart transplantation by carotid baroreflex modulation of RR interval

BACKGROUND

After heart transplantation, respiration-synchronous fluctuations (0.18 to 0.35 Hz, high frequency [HF]) in RR interval may result from atrial stretch caused by changes in venous return, but slower fluctuations (0.03 to 0.15 Hz, low frequency [LF]) not due to respiration suggest reinnervation. In normal subjects, sinusoidal neck suction selectively stimulates carotid baroreceptors and causes reflex oscillations of RR interval.

METHODS AND RESULTS

To evaluate the presence of reinnervation, we measured the power of RR-LF and RR-HF in 26 heart transplant recipients and 16 control subjects before and during sinusoidal neck suction at 0.1 Hz and 0.20 Hz (similar to but distinct from that of controlled respiration, 0.25 Hz) and before and during administration of atropine or beta-blocker (esmolol hydrochloride) by spectral analysis. All transplant recipients showed small respiratory HF fluctuations. Nonrespiratory LF fluctuations were present in 13 of 26 transplant recipients and increased with months since transplantation (r = .53, P < .01). HF neck suction induced a 0.20-Hz component in all 16 control subjects and none of the 26 transplant subjects. LF neck suction increased RR-LF (from 0.73 +/- 0.20 to 1.30 +/- 0.26 ln ms2, P < .001), similar to but less than in control subjects (from 6.12 +/- 0.21 to 8.27 +/- 0.21 ln ms2, P < .001). Atropine reduced all fluctuations in control subjects and blocked the HF increase caused by 0.20-Hz neck suction but not the LF increase during 0.10-Hz stimulation. Neck suction-induced changes in LF fluctuations persisted after administration of atropine in transplant recipients but were attenuated by esmolol hydrochloride, suggesting sympathetic rather than vagal reinnervation.

CONCLUSIONS

The presence of baroreceptor-induced RR oscillations is evidence of functional, although incomplete, autonomic reinnervation.

Loratadine in the treatment of cough associated with allergic rhinoconjunctivitis

BACKGROUND

Antihistaminic treatment of allergic asthma or cough-type asthma, including cough associated with allergic rhinocojunctivitis, has been recently reconsidered prospectively since new very potent compounds, nonsedating with anti-allergic properties, are available.

OBJECTIVE

The possible effectiveness of loratadine in the treatment of allergic cough was assessed in 20 patients with allergic rhinoconjunctivitis and cough due to Parietaria judaica during the pollen season (April to July 1993).

METHODS

Allergic patients were enrolled in a double-blind, placebo-controlled, parallel-group, randomized study, and received loratadine 10 mg/d or placebo in oral tablets for 4 weeks. Occurrence and severity of conjunctival and nasal symptoms, severity and frequency of cough attacks were assessed daily by the patients together with peak expiratory flow evaluation performed twice a day, ie, in the morning and in the evening. Physicians evaluated conjunctival and nasal signs, and spirometry on admission (before treatment), 2 and 4 weeks after treatment. On admission methacholine challenge was also performed to assess PD20. Pollen counts were assessed during the study.

RESULTS

According to patients' diary cards, ocular and nasal symptoms were progressively reduced by loratadine treatment (respectively P < .05 and P < .01), as well as cough frequency (P < .05) and cough intensity (P < .01). Peak expiratory flow rate, forced vital capacity, and forced expiratory volume in one second significantly decreased in the placebo-treated group (P < .01), while they were not modified in loratadine-treated patients, who remained normal.

CONCLUSIONS

The study suggests that loratadine may be beneficial in the treatment of allergic cough, as well as in rhinoconjunctivitis. Further studies of this may be warranted.

Antiallergic activity of loratadine: inhibition of leukotriene C4 release from human leucocytes

The H1 antagonist loratadine has the capacity to inhibit histamine release from human basophils. The aim of this study was to investigate whether loratadine can also inhibit leukotriene C4 (LTC4) release from human leucocytes. Basophil-enriched mononuclear cell suspensions were prepared by centrifugation of peripheral venous blood (n = 10) on discontinuous Percoll gradients. Leucocytes were stimulated with anti-IgE, N-formylmethionyl-leucyl-phenylalanine (FMLP) and Ca2+ ionophore A23187; immunoreactive (i) LTC4 release in the cell supernatant was measured by a competitive radioimmunoassay and histamine release was evaluated by an automated fluorometric technique. Loratadine, in the concentration range of 1-50 microM, exerted a dose-dependent inhibitory effect on IgE-mediated and IgE-independent histamine and iLTC4 release. The concentrations inhibiting 50% of histamine release were 30 microM (anti-IgE), 27 microM (FMLP) and 19 microM (Ca2+ ionophore A23187). The concentrations inhibiting 50% of iLTC4 release were 2.3 microM (anti-IgE). 11 microM (FMLP) and 1.7 microM (Ca2+ ionophore A23187). The inhibitory activity on iLTC4 release was optimal after preincubation for 2 h at 37 degrees C, and was no longer evident when leucocytes were stimulated 2 h after cell washing. Increased extracellular Ca2+ concentrations reduced the inhibitory activity of loratadine. These results indicate that loratadine has the capacity to inhibit the release of preformed and newly generated mediators from human basophil-enriched mononuclear cell suspensions.

Acute promyelocytic leukaemia cells resistant to retinoic acid show further perturbation of the RAR alpha signal transduction system

Acute promyelocytic leukaemia (APL) cell lines resistant to all-trans retinoic acid (ATRA) have been previously derived from the NB4 cell line, and characterized as having lost the expression of the intact pml/RAR alpha fusion protein. To confirm the association between ATRA-resistance and alteration in the fusion protein at the clonal level, 16 clones were generated from ATRA-resistant APL cell lines. All clones show immunological (HLA class I and II, CD11b and c, CD13 and 33), molecular and growth features similar to the parental cell lines. To investigate whether the irradiation protocol used to generate the previously reported retinoic acid-resistant NB4.306 cell line induced additional alterations that could render these cells able to escape the anti-proliferative effect of retinoic acid (ATRA), an additional ATRA-resistant APL cell line, [NB4.007/6], was generated, under the selective pressure of ATRA, from the NB4 cell line without previous radiation. This cell line shows resistance to the anti-proliferative and differentiating action of ATRA. The NB4.007/6 cell line contains the t(15;17) chromosome translocation, shows the usual pml/RAR alpha hybrid DNA but expresses no detectable amount of the usual pml/RAR alpha protein in Western blot analysis, similarly to the NB4.306 cell line. Finally, the relative resistance to ATRA of NB4.306 and NB4.007/6 was evaluated by comparing the phenotypic (CD11b) changes induced by ATRA in these two lines with those induced in the parental, ATRA-sensitive, NB4 cell line. It is estimated that NB4.306 and NB4.007/6 are about 300 and 70 times less sensitive to ATRA than the original NB4 cell line.

Presence of autoantibodies against oxidatively modified low-density lipoprotein in essential hypertension: a biochemical signature of an enhanced in vivo low-density lipoprotein oxidation

OBJECTIVE

We have previously reported that low-density lipoproteins (LDL) isolated from patients with essential hypertension are more susceptible to in vitro oxidation than lipoproteins isolated from normotensive control subjects. In the present study we investigated the occurrence of in vivo LDL oxidation in hypertensive patients.

DESIGN

The presence of antioxidatively modified LDL autoantibodies was taken as a suitable index of in vivo LDL oxidation because, after oxidative modifications, LDL express antigenic epitopes that elicit an immune response. The antibody titres were measured in plasma from untreated patients with newly diagnosed essential hypertension.

METHODS

An enzyme-linked immunosorbent assay method was employed, using native LDL, Cu(2+)-oxidized LDL and malondialdehyde-derivatized LDL (MDA-LDL) as antigens. Human serum albumin and MDA human serum albumin were also used to monitor cross-reactivity with other oxidized molecules. The antibody titre was expressed as the ratio between anti-modified and anti-native antigen absolute values.

RESULTS

The patients with essential hypertension had an antibody ratio significantly higher than control subjects with respect to anti-Cu(2+)-oxidized LDL immunoglobulins G and M, and with respect to anti-MDA-LDL immunoglobulins G and M. A significant positive correlation was found between anti-MDA-LDL and anti-Cu(2+)-oxidized LDL antibody titres. The anti-MDA human serum albumin antibody titre was not different in the two groups of patients. An inverse correlation was detected between the anti-MDA-LDL immunoglobulin M titre and the age of the patients.

CONCLUSIONS

The results obtained are consistent with the view that, during the early phases of hypertension development, LDL undergo in vivo oxidation that is mirrored by the generation of autoantibodies against epitopes of oxidized LDL. The oxidation process appears specific for LDL and might be relevant both for the progression of hypertension and for the development of the atherosclerosis that often complicates hypertension itself.