Combined effect of sodium selenite and docetaxel on PC3 metastatic prostate cancer cell line

Docetaxel and sodium selenite are well known for their anticancer properties. While resistance to docetaxel remains an obstacle in prostate cancer chemotherapy, sodium selenite, has been exploited as a new therapeutic approach. Currently, development of therapies affecting a multitude of cell targets, have been proposed as a strategy to overcome drug resistance. This association may reduce systemic toxicity counteracting a wide range of side effects. Here we report the effect of docetaxel and sodium selenite combination on the PC3 prostate cancer cell line, derived from bone metastasis. Therefore we evaluate cell growth, cell cycle progression, viability, mitochondria membrane potential, cytochrome C, Bax/Bcl2 ratio, caspase-3 expression and reactive oxygen species production. Our results suggest that sodium selenite and docetaxel combination have a synergistic effect on cell growth inhibition (67%) compared with docetaxel (22%) and sodium selenite (24%) alone. This combination also significantly induced cell death, mainly by late apoptosis vs necrosis, which is correlated with mitochondria membrane potential depletion. On the other hand, cytochrome C, Bax/Bcl2 ratio and caspase-3, known as proapoptotic factors, significantly increased in the presence of sodium selenite alone, but not in the presence of docetaxel in monotherapy or in combination with sodium selenite. These findings suggest that docetaxel and sodium selenite combination may be more effective on prostate cancer treatment than docetaxel alone warranting further evaluation of this combination in prostate cancer therapeutic approach.

Regulatory T cells in elderly patients with asthma

BACKGROUND

Airway walls in asthma present an accumulation of activated cells that determine bronchial structural changes and disease progression and severity. During the aging process, the immunoinflammatory response changes as a consequence of chronic antigenic stress.

OBJECTIVE

To evaluate T-cell subsets with regulatory functions associated with asthma in elderly patients

METHODS

A group of 153 individuals (95 with controlled asthma and 58 healthy controls) aged over 65 years was studied. Blood samples were collected for flow cytometry analyses of CD3, CD4, CD8, CD56, CD56CD8, CD3CD4CD25, CD3CD4CD25CD127, CD4HLA-DR and TCRgamma delta.

RESULTS

Asthmatic patients showed a statistically significant increase in CD4+ T cells. CD3CD4CD25high and CD3CD4CD25highCD127high cells were also significantly increased in asthmatic patients, while CD3CD4CD25highCD127low cells had similar values in asthmatics and in the control group. CD4HLA-DR cells were within the normal range in both groups. A positive correlation between CD3CD4CD25highCD127low and CD4HLA-DR was observed and gamma delta T cells were significantly decreased in the asthmatic patients compared to the controls.

CONCLUSIONS

Since T cells with regulatory functions were within normal ranges or reduced in asthmatic patients compared to healthy controls, at least in basal conditions, it can be speculated that they probably play a limited role in chronic asthma in elderly patients.These data suggest an absence of a modulatory effect on the inflammatory response that characterizes asthma and allergy, which in turn would facilitate the persistence of disease in this population. Underlying inflammatory processes that are involved in chronic diseases associated with aging could provide an additional explanation for the attenuated differences observed between asthmatic and nonasthmatic individuals.

The evaluation of neopterin and antioxidants in long lasting asthma

Asthma is a condition characterised by a chronic immunoinflammatory response to different triggers. Neopterin (NPT) is synthesised by human macrophages upon stimulation with interferon-gamma and is also capable of enhancing the oxidative potential of reactive oxygen species. NPT is useful for the monitoring of cell-mediated (Th1-type) immune activation. This study analysed the behaviour of NPT in long lasting asthma, considering its role as a marker of Th1 environment. Allergic parameters (skin prick tests, Immunoglobin E (IgE), and eosinophil count) and NPT were evaluated in an asthmatic group and in a control group. We also analysed the C Reactive Protein (CRP) concentration, Total Antioxidant Status (TAS) and Superoxide Dismutase Enzyme (SOD) in both groups. A group of individuals aged over 65 years old was selected. It included 64 asthmatic patients (72+/-5 years) and 41 healthy individuals (79+/-7 years). Blood cell counts showed statistically different median values of eosinophils (5.42+/-4.7 vs 2.8+/-2.8;p<.04), IgE (493.2+/-549.8 vs 85.3+/-194.UI/ml; p=.000) and NPT was non-statistically decreased (2.4+/-2.8 vs 4.0+/-4.7 ng/ml) in allergic asthmatic patients when compared with non-allergic asthmatic patients. Both allergic and non-allergic asthmatic patients presented a statistically significant decreased expression of TAS (0.84+/-0.14/0.86+/-0.11 vs 0.91+/-0.10 mM) and SOD (584.8+/-108.7/595.6+/-235.9 vs 822.9+/-179.5) when compared with normal control subjects. Our results suggest macrophage involvement in asthma pathogenesis. The deficit in antioxidant defence impacts negatively on this disease. The increase of NPT values in non-allergic asthma consolidates these affirmations and mapping this parameter should be part of the work of an analytical study panel as it may lead to allergic asthma being distinguished from non- allergic asthma.

[Deep lung--cellular reaction to HIV]

The course of HIV infection is accompanied by a wide individual variability. The complex and large interplay between host and viral factors is crucial in the disease's evolution. The lung has been recognised from the beginning of the disease as one of the main targets of infectious and non-infectious complications of AIDS. In this setting both anatomic and immunologic particularities of this organ play an important role. The hallmark of HIV is progressive immune dysfunction. Despite the intensive research into the pathogenesis, several questions remain to be answered on the dynamic effects of HIV on pulmonary cells. Previous studies in which we have participated showed the early presence of lymphocytic alveolitis from the asymptomatic phase of infection. Since then, many collected data has brought new insights into the immune and biochemical mechanisms involving HIV cell entry, as well as target cells, cytokines and other cellular mediators. In this context, the discovery that specific chemokine receptors could act as co-receptors for HIV, allowed a better understanding of the mechanisms underlying viral cellular entry and tropism. On this issue several authors have reported that in addition to the CD4 molecule, most strains of HIV use the chemokine receptor CCR5 for viral attachment and entry into the host cells. This receptor seems to be very important in disease transmission, whereas CXCR4 receptor tends to be used by the viral strains that emerge later in the disease in addition to or instead of the CCR5.

AIMS

To evaluate the pulmonary cellular dynamics in AIDS patients regarding the viral load in bronchoalveolar lavage fluid (LLBA), as well as cellularity and tropism through CCR5 and CXCR4 receptors.

MATERIAL

14 AIDS patients were enrolled in this study, with a mean age of 39 +/- 14.3 years (9 males and 5 females) all HIV1, heterosexuals, 6 smokers and 8 non-smokers, none of them drug addicts. These patients were referred to bronchoscopy with BAL, for clinical suspicion of opportunistic lung infections. These patients were later divided into two groups: Group I (recent diagnosis) and Group II (non-recent diagnosis). While all patients had AIDS, group I had also recent diagnosis of opportunistic infections and had not received yet anti-retroviral therapy whilst group II had a long-term disease evolution with several opportunistic episodes and anti-retroviral therapeutic.

METHODS

BAL was performed both in the middle bronchus in diffuse or in other segmentar bronchus, depending on radiographic abnormalities. Plasma viral load was performed through PCR-RT in blood samples with EDTA, centrifuged and frozen (-80 masculine Celsius) in the first 4 hours after being collected. The viral load in BALf was quantified in 9 patients using the automatized Cobas Ampliprep/Cobas Amplicor HIV1 Monitor TM Test, version 1.5 Roche Diagnostic Systems. The results were expressed in a numeric scale, with a dynamic variation of 50-750.000 copies of RNA HIV1/cm3 and later converted into a logarithmic scale. In 10 patients an immunological study was carried out in BALf and blood to quantify the lymphocyte populations and subsets (CD3, CD4, CD8, CD19, CD56 and CD56CD8) as well as the receptors CD3CCR5, CD4CCR5, CD8CCR5, CCR5Mø, CXCR4, CD3CXCR4, CXCR4CD14 and co-stimulatory molecule CD28, CD3CD28, CD4CD28, CD8CD28 through monoclonal antibodies - CD8FITC, CD19FITC, CD3PE, CD56PE, CD4PECY5-Lymphogram Cytognos; CCR5PE, CXCRFITC-R & D Systems; CD8Cy5 and CD3Cy5-DaKo, CD4PE, CD14PE, CD28FITC- Immunotech; CD4FITC-CLB, CD8Percp- Beckton Dickinson and CD3 APC - Beckton Dickinson, by flow cytometry (Facs Calibur-Beckton-Dickinson) with 3 or 4 fluorescences - FL1- -FITC, FL2-PE, FL3-PECY, FL4-APC. In the statistical analysis, we used the Student t-test, and li- near correlation.

RESULTS

Presence of HIV1 in BALf (2.95 log +/- 3.08 log), in small levels compared with plasma viral loads (5.89 log +/-5.90 log) (Table IV). There was great variability of viral loads in BALf as there was in blood independent of the time elapsed between diagnosis and the exam. As for the lymphocytic populations and subsets in blood (Table V) determined in 13 patients, there was a significant fall of total lymphocytes as well as of their subsets, although more marked in CD4 cells; 42.9% had CD4 levels < 50 cels/mm3 and only 2 patients (n masculine 12, 13) had CD4> 250 cels/mm3. The CD19 was reduced with an individual distribution similar to the CD4 subset. In most cases, the fall of CD8 accompanied the decrease of CD4 and CD19 (patients-n masculine 7 and 8). The lymphocyte populations and subsets in BALf (10 patients) (Table VI) showed a percentual distribution similar to that observed in blood (Table VII) for CD3, CD19, CD4 and CD8 lymphocytes, although the percentage of T cells was higher than in blood (94.5 +/- 5 /84.1 +/-10.4) as opposed to B cells (2.2 +/-3 /10.4 +/- 9.6). In BALf CD8 T cells were higher than in blood (77.7 +/- 17.6 /67.6 +/- 4.2), which was not observed for the CD4 lymphocytes (8.1 +/- 9.5 BALf vs.10.4 +/- 9.6 in blood). The natural killer activity expressed by CD56 T cells had important individual variations in both biological fluids: higher levels in blood than in BALf (9.1 +/-8 /2.9 +/-1.9). The cytotoxic activity of CD56CD8 was similar in blood and in BALf (2.2 +/- 2 / 1.7+/- 1.2) while the individual distribution seemed more homogeneous in BALf (Table VI) than in blood (Table VII). The double-negative (DN) cells had slightly higher values in BALf (7.6 +/- 4.5 vs 5.6 +/- 5.3). Curiously, in BALf we observed a higher percentage of less differentiated cells (13 +/- 13.6) (Table VI). The analysis of the receptors CCR5 and CXCR4 showed in general terms different behaviour concerning the two biological means (Tables VI and VII). Thus, the CCR5 CD3 was higher in blood (10.9+/- 13.2) than in BALf (8.4 +/- +/- 3.5) while the CCR5 CD4 and CCR5 CD8 had an increased expression in BALf in relation to blood ( 2 +/- 2.3 and 4.9 +/- 3.7 / 0.9 +/- 0.7 and 4.1 +/- 4.0 respectively). Concerning the expression of this receptor on monocyte macrophage lineage a marked higher value was attained in BALft (77.8 +/- +/- 41 in BALf vs. 18.7 +/- 15 in blood). On the contrary the total expression of CXCR4 was higher in BALf (31 +/- 19.9) than in blood (16.4 +/- +/- 8.1). This tendency extended equally to the T lymphocytes (26.6 +/- 19.8 vs. 10.7 +/-7.6) and also to the monocyte-macrophage lineage in an exuberant manner (84.5 +/- 30.2 / 4.8 +/- 4.6). The co- stimulatory activity of CD28 showed higher values in blood (22.8 +/- 16.2) than in BALf (15.9 +/- +/- 10.1) for total T cells, CD4 and CD8 lymphocytes 22.5 +/-16.7; 7.8 +/- 8.3; 13.3 +/- 8.3 / 16.5 +/- +/- 10.5; 2.9 +/- 2.8; 10.8 +/- 8.0 respectively).

CONCLUSIONS

1. HIV infection is responsible for important and extensive abnormalities in lung host defences. 2. The complex interaction between host and aggressor as well as the immune response particularly represented by natural killer and cytotoxic activities, apoptosis, and opportunistic diseases or others, therapeutics and other factors may contribute to the difficulty in obtaining homogenous medical samples within research. There are also ethical issues that restrict a purely scientific approach to these patients. 3. These results point to a pulmonary response to HIV in a compartmentalised fashion according to the dynamic cellular elements involved and receptors in which the latter had distinct profiles related to the biological fluids. In this context, the lung compartimental response is particularly dependent on alveolar macrophages activity which is from the beginning the cornerstone of this process and is the last cellular defense mechanism in this territory when all others are profoundly affected. 4. The dynamics of chemokines receptors may be very important in therapeutic approach as the blockage of the CCR5 receptor does not seem to trigger an increased expression of CXCR4 strains. In fact, we found that CXCR4 remained high in monocyte-macrophage cells throughout infection and its expression was increased in T-lymphocytes in Group II patients as opposed to CCR5 behavior in BALf which significantly decreases. However, in blood, CCR5 expression increased, unlike CXCR4. 5. Due to high co-existing opportunistic infections (71.4%) we cannot ignore the hypothesis that this increased expression of CXCR4 was a result of the modulation induced by opportunistic agents. 6. Finally, this striking individual variability undoubtly has clinical implications. This makes a case-by-case management strategy the correct approach.

Apoptosis and asthma in the elderly

BACKGROUND

Asthma is a chronic inflammatory disorder of the airways. The persistence of airway inflammation depends on a decrease in apoptosis of T lymphocytes and eosinophils and survival of these activated cells. T lymphocytes expressing gamma delta receptors can be identified in human lungs and play an important role in immune defence against pathogens and in the regulation of chronic inflammation. Aging is associated with evidence of some immune dysregulation.

OBJECTIVE

The aim of this study was to analyze the apoptosis receptors of T lymphocytes in long-lasting asthma, to establish their correlation with activation markers such as CD25+ and human leukocyte antigen (HLA)-DR+, and to analyze the gama delta T cell expression in this disease.

METHODS

A group of 64 individuals (group A) who had had asthma for more than 30 years (mean age [+/-SD] 72 +/- 5 years) and 61 healthy individuals acting as controls--group B with 41 individuals (mean age 79 +/- 7 years) and group C with 20 individuals (mean age 38 +/- 12 years) were included in the study. All subjects underwent clinical evaluation and spirometric testing. Peripheral blood cells were stained with monoclonal antibodies anti-CD3, anti-CD4, anti-CD8, anti-CD25, anti-TCR gamma delta, anti-HLA-DR and anti-CD95. Statistical comparisons were performed between the asthmatics and the elderly control group and between the elderly control group and the adult control group.

RESULTS

The average percentage of predicted forced expiratory volume in the first second was 73.6 gamma delta 25.3. The mean values of T cell receptors for asthma group A vs elderly control group B vs adult control group C respectively, were the following: CD3, 74.9+/-7 vs. 74.8 +/- 8.8 (P=ns) vs. 76.7 +/- 4.2 (P=ns); CD4, 48.8 +/- 8.7 vs. 43.5 +/- 10.2 (P=ns) vs. 44.8 +/- 3.8 (P=ns); CD8, 23.3 +/- 7.9 vs. 25.7 +/- 10.2 (P=ns) vs. 25.6 +/- 4.5 (P=ns); CD25, 14.3 +/- 5.9 vs. 22.4 +/- 7.8 (P = .0001) vs. 5.5 +/- 2.4 (P = .0001); TCR gamma delta, 2.8 +/- 2.1 vs. 4.1 +/- 3.3 (P < .05) vs. 4.6 +/- 2.1 (P=ns); HLA-DR, 18.4 +/- 9.2 vs. 17.8 +/- 5.9 (P=ns) vs. 15.4 +/- 5.1 (P=ns) and CD95, 49.3 +/- 13.7 vs. 52.6 +/- 12.1 (P=ns) vs. 13.8 +/- 10.8 (P = .0001).

CONCLUSIONS

The immunological and inflammatory changes related to ageing may cause an increase in CD95 and CD25 T cell expression. In asthma, blood cells may express increased activation and apoptosis markers but in elderly patients taking steroids, these receptors remain within normal ranges. The number of gamma delta T cells may be lower in long-lasting asthma, and have a limited modulatory effect on allergic inflammatory reactions. The evaluation of patients with long-lasting asthma should take into account the immunological and inflammatory changes present in the elderly in order to avoid results being misinterpreted.

Elevated neopterin levels in non-allergic asthma

Neopterin is synthesized by human monocyte-derived macrophages upon stimulation with interferon-gamma (IFN-gamma). Measurement of neopterin concentration is useful to monitor cell-mediated (Th1-type) immune activation. In this study, we aimed to analyze the behaviour of neopterin in long lasting asthma considering its role as a marker of the Th1 environment and to establish the distinction between patients belonging either to the allergic or the non-allergic population, particularly in the elderly where asthma is often under diagnosed. Therefore we evaluated allergic parameters such as skin prick tests, IgE and hemogram (eosinophils count), and we compared our findings with neopterin values found in an age-matched control population. A group of individuals older than 65 was selected. It included 64 asthmatic patients (mean age 72+/-5 years) and 41 healthy individuals (mean age 79+/-7 years). In our study population, 42 patients presented positive skin tests, mainly to house dust mites. All patients were clinically stable and presented an average percentage of predicted forced expiratory volume in the first second (FEV1) of 73.6+/-25.3 and predicted median expiratory flow percentage (MEF50) of 38.8+/-26.7. Blood cell counts showed statistically different mean values of eosinophils between allergic and non-allergic controls (5.42+/-4.7% versus 2.8+/-2.8%; p<0.04). IgE values were increased in allergic asthmatic patients when compared with non-allergic asthmatic patients (493.2+/-549.8IU/ml versus 85.3+/-194.4IU/ml; p=0.000). Allergic asthmatic patients presented mean neopterin levels similar to those found in the control group (2.4+/-2.8ng/ml versus 2.1+/-1.9ng/ml). In contrast, in non-allergic asthmatic patients these values were higher when compared with the control group (4.0+/-4.7ng/ml versus 2.1+/-1.9ng/ml). Neopterin levels were lower in allergic asthmatic patients when compared with non-allergic asthmatic patients (2.4+/-2.8ng/ml versus 4.0+/-4.7ng/ml). Within asthmatic patients, those with higher neopterin values (>2.1ng/ml) presented lower mean IgE values (IgE</=336.58IU) than those with lower neopterin values (</=2.1ng/ml) who presented mean IgE values of 402.70IU. Our initial findings may lead to a better understanding of the immunoinflammatory pathways in asthma. Further studies will probably show that serum neopterin could became a useful marker for asthma classification including in elderly patients with long lasting disease.

CD26/DPPIV expression and 8-azaguanine response in T-acute lymphoblastic leukaemia cell lines in culture

Dipeptidyl peptidase IV, a cell membrane surface protease also known as CD26 (CD26/DPPIV), is known to play multiple functions in human organism, where it is largely expressed, for instance, in the development of human cancer and metastasis as well as in chemotherapy response. The objective of this work was to study the CD26 membrane expression and DPPIV activity in T-acute leukaemia cell lines (CEM and MOLT3) in culture, in order to observe the modification of its expression under the 8-azaguanine treatment. Cell line samples were incubated, some without different azaguanine concentration and others with, ranging from 10 to 100muM. Cell surface CD26 expression has been identified by flow cytometry and DPPIV activity, in cultured medium, was fluorimetrically measured. Results we have observed showed that 8-azaguanine induced a decrease in cell viability in a dose, time and cell type dependent manner with MOLT3 cells being the most sensitive to 8-azaguanine citotoxic effects (24h IC50: +/-10muM) when compared with CEM cells (24h IC50: +/-100muM). In the same experimental conditions, MOLT3 cell treated with 8-azaguanine shows an increase in CD26 expression (MIF) compared with that of CEM cell submitted to the same conditions (65.4+/-1.3 versus 18.7+/-1.7). DPPIV activity in culture medium supernatant of CEM versus MOLT3 controls cells (1.91+/-0.43 versus 2.06+/-0.50) and of CEM versus MOLT3 treated cells (2.10+/-0.16 versus 1.89+/-0.04) did not show a significant difference. These preliminary results suggest that 8-azaguanine stimulates CD26 expression which may be related to cellular sensitivity to 8-azaguanine.