A three-gene signature marks the time to locoregional recurrence in luminal-like breast cancer.

BACKGROUND: Gene expression profiling (GEP)-based prognostic signatures are being rapidly integrated into clinical decision making for systemic management of breast cancer patients. However, GEP remains relatively underdeveloped for locoregional risk assessment. Yet, locoregional recurrence (LRR), especially early after surgery, is associated with poor survival. PATIENTS AND METHODS: GEP was carried out on two independent luminal-like breast cancer cohorts of patients developing early (≤5 years after surgery) or late (>5 years) LRR and used, by a training and testing approach, to build a gene signature able to intercept women at risk of developing early LRR. The GEP data of two in silico datasets and of a third independent cohort were used to explore its prognostic value. RESULTS: Analysis of the first two cohorts led to the identification of three genes, CSTB, CCDC91 and ITGB1, whose expression, derived by principal component analysis, generated a three-gene signature significantly associated with early LRR in both cohorts (P value <0.001 and 0.005, respectively), overcoming the discriminatory capability of age, hormone receptor status and therapy. Remarkably, the integration of the signature with these clinical variables led to an area under the curve of 0.878 [95% confidence interval (CI) 0.810-0.945]. In in silico datasets we found that the three-gene signature retained its association, showing higher values in the early relapsed patients. Moreover, in the third additional cohort, the signature significantly associated with relapse-free survival (hazard ratio 1.56, 95% CI 1.04-2.35). CONCLUSIONS: Our three-gene signature represents a new exploitable tool to aid treatment choice in patients with luminal-like breast cancer at risk of developing early recurrence.

Comparative analysis of full-time, half-time, and quarter-time myocardial ECG-gated SPECT quantification in normal-weight and overweight patients.

BACKGROUND: The introduction of a camera-based dose-reduction strategy in myocardial perfusion imaging (MPI) clinical setting entails the definition of objective and reproducible criteria for establishing the amount of activity to be injected. AIM: The aim is to evaluate the impact of count statistics on the estimation of summed-scores (SS), end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF). METHODS: Data rest/stress ECG-gated SPECT (2-day protocol and 8 MBq·kg-1) were acquired with Bright View gamma camera and Astonish algorithm for 40 normal-weight and 40 overweight patients. Assuming that count statistics of shorter acquisition time may simulate that of lower injected activity, three simultaneous scans (full-time, half-time, and quarter-time scans) were started at the same time but with different acquisition time/projection (30, 15 and 8 seconds). RESULTS: A significant difference between SS values of half-time and quarter-time stress scans was found for overweight group (P = .006). Post hoc test showed significant differences for ESV (P < .05), EDV (P < .01) and EF (P < .05) between half-time and quarter-time scans for both patient groups. CONCLUSIONS: The reduction of the count-statistics to a quarter of the MPI reference influenced negatively the quantification in overweight patients. The decrease of radiopharmaceutical activity to 25% of the reference seems practicable for normal-weight patients, while it is more appropriate an activity reduction limited to 50% for overweight and obese patients.

Quinolinic acid induced neurodegeneration in the striatum: a combined in vivo and in vitro analysis of receptor changes and microglia activation.

PURPOSE: Huntington's disease (HD) is a progressive neurodegenerative disorder, which is characterised by prominent neuronal cell loss in the basal ganglia with motor and cognitive disturbances. One of the most well-studied pharmacological models of HD is produced by local injection in the rat brain striatum of the excitotoxin quinolinic acid (QA), which produces many of the distinctive features of this human neurodegenerative disorder. Here, we report a detailed analysis, obtained both in vivo and in vitro of this pharmacological model of HD. MATERIALS AND METHODS: By combining emission tomography (PET) with autoradiographic and immunocytochemical confocal laser techniques, we quantified in the QA-injected striatum the temporal behavior (from 1 to 60 days from the excitotoxic insult) of neuronal cell density and receptor availability (adenosine A(2A) and dopamine D(2) receptors) together with the degree of microglia activation. RESULTS: Both approaches showed a loss of adenosine A(2A) and dopamine D(2) receptors paralleled by an increase of microglial activation. CONCLUSION: This combined longitudinal analysis of the disease progression, which suggested an impairment of neurotransmission, neuronal integrity and a reversible activation of brain inflammatory processes, might represent a more quantitative approach to compare the differential effects of treatments in slowing down or reversing HD in rodent models with potential applications to human patients.

Two-dimensional vs three-dimensional imaging in whole body oncologic PET/CT: a Discovery-STE phantom and patient study.

AIM: To evaluate the performance of the positron emission tomography (PET)/computed tomography (CT) Discovery-STE (D-STE) scanner for lesion detectability in two-dimensional (2D) and three-dimensional (3D) acquisition. METHODS: A NEMA 2001 Image-Quality phantom with 11 lesions (7-37 mm in diameter) filled with a solution of 18F (lesion/background concentration ratio: 4.4) was studied. 2D and 3D PET scans were sequentially acquired (10 min each) in list mode (LM). Each scan was unlisted into 4, 3 and 2-min scans. Ten [18F]FDG PET oncological patient studies were also evaluated. Each patient underwent a 3D PET/CT whole body scan, followed by a 2D PET scan (4 min LM) and a 3D PET scan (4 min LM) over a single field of view. Both 2D and 3D scans were unlisted in 3 and 2-min scans. Data were evaluated quantitatively by calculating quality measurements and qualitatively by two physicians who judged lesion detectability compared to statistical variations in background activity. RESULTS: Quantitative and qualitative evaluations showed the superiority of 3D over 2D across all measures of quality. In particular, lesion detectability was better in 3D than in 2D at equal scan times and 3D acquisition provided images comparable in quality to 2D in approximately half the time. Interobserver variability was lower in evaluation of 3D scans and lesion shape and volume were better depicted. CONCLUSION: In oncological applications, the D-STE system demonstrated good performance in 2D and 3D acquisition, while 3D exhibited better image quality, data accuracy and consistency of lesion detectability, resulting in shorter scan times and higher patient throughput.

Resveratrol derivatives and their role as potassium channels modulators.

A series of stilbenoid analogues of resveratrol (trans-3,4',5-trihydroxystilbene) with a stilbenic or a bibenzylic skeleton have been prepared by partial synthesis from resveratrol and dihydroresveratrol. The synthesized compounds have been evaluated for their ability to modulate voltage-gated channels.

Evaluation of the clinical performances of a large NaI(Tl) crystal 3D PET scanner.

AIM: This study was aimed at assessing the clinical performances of a NaI(Tl) crystal 3D PET scanner, C-PET (ADAC-UGM), using a multi-ring 2D BGO PET scanner (multi-ring PET), as a reference. METHODS: Thirty-seven oncological patients were studied in sequence with multi-ring PET and C-PET, within 30 days of a CT study. In order to assess the behaviour of C-PET in relation to acquisition count rate, patients were divided into 3 groups according to the count rate at the time of the C-PET scan acquisition. Group A (n=21): 3000-5000 kcounts/sec (recommended count rate range); Group B (n=8): <3000 Kcounts/sec and Group C (n=8): >5000 Kcounts/sec. RESULTS: The number of lesions detected by multi-ring PET and C-PET, classified according to size, was compared. For Group A and Group B there was a good agreement between C-PET and multi-ring PET in terms of lesion detectability (relative sensitivity: 99.9% and 96.0%, respectively), while for Group C the relative sensitivity of C-PET was 61.9%. CONCLUSION: Optimal performances of the C-PET scanner can thus be obtained at a count rate within or below the recommended range. Despite a lower lesion/background contrast resulting from a high scatter and random noise, the sensitivity of C-PET in detecting hypermetabolic lesions is comparable to that of multi-ring PET. These findings are discussed in relation to the physical performance of the two scanners and particularly in relation to the 3D vs 2D acquisition modality.

Glucose- and arginine-induced insulin secretion by human pancreatic beta-cells: the role of HERG K(+) channels in firing and release.

The human ether-a-go-go-related genes (herg) are expressed in tissues other than heart and brain where the HERG K(+) channels are known to regulate the repolarization of the heart action potential and the neuronal spike-frequency accommodation. We provide evidence that herg1 transcripts are present in human pancreatic islets that were used to study both insulin secretion and electrical activity with radioimmunoassay and single cell perforated patch-clamp techniques, respectively. Glucose- and arginine-induced islets insulin secretion data suggested a net increase of release under perfusion with antiarrhythmic drugs known to selectively block HERG channels. Indeed we could routinely isolate a K(+) current that was recognized as biophysically and pharmacologically similar to the HERG current. An analysis of the glucose- and arginine-induced electrical activity (several applications during 30 min) in terms of firing frequency and putative insulin release was done in control and in the presence of selective blockers of HERG channels: the firing frequency and the release increased by 32% and 77%, respectively. It is concluded that HERG channels have a crucial role in regulating insulin secretion and firing of human beta-cells. This raises the possibility that some genetically characterized hyperinsulinemic diseases of unknown origin might involve mutations in the HERG channels.

Excitable properties in astrocytes derived from human embryonic CNS stem cells.

Although it is widely believed that astrocytes lack excitability in adult tissue, primitive action potential-like responses have been elicited from holding potentials negative to -80 mV, in cultured and injury-induced gliotic rodent astrocytes and in human glia under pathological conditions such as glioblastomas and temporal lobe epilepsy. The present study was designed to investigate the properties of astrocytes (identified by immunoreactivity for glial fibrillary acidic protein) derived from multipotent human embryonic CNS stem cells and cultured for 12-25 days in differentiating conditions. We describe here for the first time that brief (1 ms) current pulses elicit spikes from a resting potential (VREST) of approximately -37 mV and, more interestingly, that spontaneous firing can be occasionally recorded in human astrocytes. A voltage-clamp study revealed that in these cells: (i) the half-inactivation of the tetrodotoxin (TTX)-sensitive Na+ channels is around VREST; (ii) the delayed rectifier K+ current is very small; (iii) the ever-present transient outward A-type K+ channels are paradoxically capable of inhibiting the action potentials elicited from a negative membrane potential (-55 to -60 mV); and (iv) inwardly rectifying currents are not present. The responses predicted from a simulation model are in agreement with the experiments. As suggested by recent studies, the decrease of Na+ channel expression and the changes of the electrophysiological properties during the postnatal maturation of the CNS seem to exclude the possibility that astrocytes may play an excitable role in adult tissue. Our data show that excitability and firing should be considered an intrinsic attribute of human astrocytes during CNS development. This is likely to have physiological importance because the role of astrocytes during development is different from the [K+]o-buffering role played in adult CNS, namely the glutamate release and/or the guiding of migrating neurons.

Altered expression of HLA-A,B specificities on acute lymphoid and myeloid leukaemia blasts.

HLA-A,B specificities were analysed on the neoplastic blasts of a panel of 69 lymphoblastic (ALL) and 50 non lymphoblastic (ANLL) acute leukaemias at onset using the standard lymphocytotoxicity technique. Analysis of the number of detected specificities per locus and, when possible, comparison of the results with those obtained on lymphocytes of the same patients during remission revealed many alterations in the expression of A,B specificities including extra specificities both at the HLA-A and -B loci mainly on lymphoblasts and missed specificities mainly at the HLA-B locus on myeloblasts. Lack of A,B antigens was complete in 6.2% of all tested samples (9% of ANLL) and selective for all the products of one locus in 16.8% of all tested samples (27.7% of ANLL). A decrease of class I molecules on the cell surface was evidenced with MoAb W6/32 on blasts missing detectable serological specificities.

Gamma-IFN induces a differential expression of HLA-DR, DQ and DP antigens on peripheral blood myeloid leukemic blasts at various stages of differentiation.

Using specific monoclonal antibodies and the indirect immunofluorescence technique, peripheral blood myeloid leukemic blasts from 49 patients were studied for DR expression, 42 for DQ and nine for DP after four days of culture without and with gamma-IFN. The expression of class II molecules on untreated cells depended upon the stage of differentiation and was maximal for DR antigens and lower for DP, while DQ was present only in a small percentage of M2, M4 or M5 blasts. M3 blasts lacked both DR and DQ. Maximal increase of surface expression induced by gamma-IFN was observed for DR molecules independently from the differentiation stage. No significant modification was seen for DQ. Preliminary data concerning DP indicate an increased expression in some of the tested samples. Thus the results obtained on peripheral blood blasts parallel previous observations on leukemic cell lines.

Expression of class I-like alloantigens on leukemic cells is not correlated with the amount of HLA-A,B,C molecules.

The expression of class I-like allospecificities on leukemic blasts is not correlated to the amount of HLA-A,B,C molecules, as measured with MoAb W6/32 and IIF, nor with the quantitative expression of HLA-A molecules evaluated by absorption studies.

New HLA class I-like alloantigens expressed on blast cells.

New beta 2-microglobulin (beta 2-m)-associated, HLA-linked alloantigens, selectively expressed on phytohaemagglutinin (PHA)-activated lymphocytes, were identified using human alloantisera. Reactivity of the antisera against activated cells correlated with HLA-A2, A10 and A28 specificities. The new alloantigens were undetectable on peripheral blood mononuclear cells, B lymphocytes and platelets using either the lymphocytotoxicity or the absorption techniques, and appeared on lymphocytes upon PHA activation, with time-dependent kinetics. They were found on some, but not all, acute leukaemias of B, T and myeloid origin, being absent from chronic B lymphocytic leukaemias. The presence of the new beta 2-microglobulin-associated allospecificities was not correlated with the quantity of classical class I antigens present, as analysed on different cell types by flow cytometry. Thus, these antigenic determinants appear to be different from the classical HLA class I antigens and could be the human counterpart of the murine Qa system or of the second H-2K gene.