Radiation induced apoptosis and initial DNA damage are inversely related in locally advanced breast cancer patients.

Background. DNA-damage assays, quantifying the initial number of DNA double-strand breaks induced by radiation, have been proposed as a predictive test for radiation-induced toxicity. Determination of radiation-induced apoptosis in peripheral blood lymphocytes by flow cytometry analysis has also been proposed as an approach for predicting normal tissue responses following radiotherapy. The aim of the present study was to explore the association between initial DNA damage, estimated by the number of double-strand breaks induced by a given radiation dose, and the radio-induced apoptosis rates observed. Methods. Peripheral blood lymphocytes were taken from 26 consecutive patients with locally advanced breast carcinoma. Radiosensitivity of lymphocytes was quantified as the initial number of DNA double-strand breaks induced per Gy and per DNA unit (200 Mbp). Radio-induced apoptosis at 1, 2 and 8 Gy was measured by flow cytometry using annexin V/propidium iodide. Results. Radiation-induced apoptosis increased in order to radiation dose and data fitted to a semi logarithmic mathematical model. A positive correlation was found among radio-induced apoptosis values at different radiation doses: 1, 2 and 8 Gy (p < 0.0001 in all cases). Mean DSB/Gy/DNA unit obtained was 1.70 ± 0.83 (range 0.63-4.08; median, 1.46). A statistically significant inverse correlation was found between initial damage to DNA and radio-induced apoptosis at 1 Gy (p = 0.034). A trend toward 2 Gy (p = 0.057) and 8 Gy (p = 0.067) was observed after 24 hours of incubation. Conclusions. An inverse association was observed for the first time between these variables, both considered as predictive factors to radiation toxicity.

Combined low initial DNA damage and high radiation-induced apoptosis confers clinical resistance to long-term toxicity in breast cancer patients treated with high-dose radiotherapy

BACKGROUND. Either higher levels of initial DNA damage or lower levels of radiation-induced apoptosis in peripheral blood lymphocytes have been associated to increased risk for develop late radiation-induced toxicity. It has been recently published that these two predictive tests are inversely related. The aim of the present study was to investigate the combined role of both tests in relation to clinical radiation-induced toxicity in a set of breast cancer patients treated with high dose hyperfractionated radical radiotherapy. METHODS. Peripheral blood lymphocytes were taken from 26 consecutive patients with locally advanced breast carcinoma treated with high-dose hyperfractioned radical radiotherapy. Acute and late cutaneous and subcutaneous toxicity was evaluated using the Radiation Therapy Oncology Group morbidity scoring schema. The mean follow-up of survivors (n = 13) was 197.23 months. Radiosensitivity of lymphocytes was quantified as the initial number of DNA double-strand breaks induced per Gy and per DNA unit (200 Mbp). Radiation-induced apoptosis (RIA) at 1, 2 and 8 Gy was measured by flow cytometry using annexin V/propidium iodide. RESULTS. Mean DSB/Gy/DNA unit obtained was 1.70 ± 0.83 (range 0.63-4.08; median, 1.46). Radiation-induced apoptosis increased with radiation dose (median 12.36, 17.79 and 24.83 for 1, 2, and 8 Gy respectively). We observed that those "expected resistant patients" (DSB values lower than 1.78 DSB/Gy per 200 Mbp and RIA values over 9.58, 14.40 or 24.83 for 1, 2 and 8 Gy respectively) were at low risk of suffer severe subcutaneous late toxicity (HR 0.223, 95%CI 0.073-0.678, P = 0.008; HR 0.206, 95%CI 0.063-0.677, P = 0.009; HR 0.239, 95%CI 0.062-0.929, P = 0.039, for RIA at 1, 2 and 8 Gy respectively) in multivariate analysis. CONCLUSIONS. A radiation-resistant profile is proposed, where those patients who presented lower levels of initial DNA damage and higher levels of radiation induced apoptosis were at low risk of suffer severe subcutaneous late toxicity after clinical treatment at high radiation doses in our series. However, due to the small sample size, other prospective studies with higher number of patients are needed to validate these results.

Pharmacological administration of the isoflavone daidzein enhances cell proliferation and reduces high fat diet-induced apoptosis and gliosis in the rat hippocampus.

Soy extracts have been claimed to be neuroprotective against brain insults, an effect related to the estrogenic properties of isoflavones. However, the effects of individual isoflavones on obesity-induced disruption of adult neurogenesis have not yet been analyzed. In the present study we explore the effects of pharmacological administration of daidzein, a main soy isoflavone, in cell proliferation, cell apoptosis and gliosis in the adult hippocampus of animals exposed to a very high-fat diet. Rats made obese after 12-week exposure to a standard or high-fat (HFD, 60%) diets were treated with daidzein (50 mg kg(-1)) for 13 days. Then, plasma levels of metabolites and metabolic hormones, cell proliferation in the subgranular zone of the dentate gyrus (SGZ), and immunohistochemical markers of hippocampal cell apoptosis (caspase-3), gliosis (GFAP and Iba-1), food reward factor FosB and estrogen receptor alpha (ERα) were analyzed. Treatment with daidzein reduced food/caloric intake and body weight gain in obese rats. This was associated with glucose tolerance, low levels of HDL-cholesterol, insulin, adiponectin and testosterone, and high levels of leptin and 17β-estradiol. Daidzein increased the number of phospho-histone H3 and 5-bromo-2-deoxyuridine (BrdU)-ir cells detected in the SGZ of standard diet and HFD-fed rats. Daidzein reversed the HFD-associated enhanced immunohistochemical expression of caspase-3, FosB, GFAP, Iba-1 and ERα in the hippocampus, being more prominent in the dentate gyrus. These results suggest that pharmacological treatment with isoflavones regulates metabolic alterations associated with enhancement of cell proliferation and reduction of apoptosis and gliosis in response to high-fat diet.

Assay for high glucose-mediated islet cell sensitization to apoptosis induced by streptozotocin and cytokines

Pancreatic beta-cell apoptosis is known to participate in the beta-cell destruction process that occurs in diabetes. It has been described that high glucose level induces a hyperfunctional status which could provoke apoptosis. This phenomenon is known as glucotoxicity and has been proposed that it can play a role in type 1 diabetes mellitus pathogenesis. In this study we develop an experimental design to sensitize pancreatic islet cells by high glucose to streptozotocin (STZ) and proinflammatory cytokines [interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma]-induced apoptosis. This method is appropriate for subsequent quantification of apoptotic islet cells stained with Tdt-mediated dUTP Nick-End Labeling (TUNEL) and protein expression assays by Western Blotting (WB).

The Chemotherapeutic Drug 5-Fluorouracil Promotes PKR-Mediated Apoptosis in a p53-Independent Manner in Colon and Breast Cancer Cells

The chemotherapeutic drug 5-FU is widely used in the treatment of a range of cancers, but resistance to the drug remains a major clinical problem. Since defects in the mediators of apoptosis may account for chemo-resistance, the identification of new targets involved in 5-FU-induced apoptosis is of main clinical interest. We have identified the ds-RNA-dependent protein kinase (PKR)as a key molecular target of 5-FU involved in apoptosis induction in human colon and breast cancer cell lines. PKR distribution and activation, apoptosis induction and cytotoxic effects were analyzed during 5-FU and 5-FU/IFNalpha treatment in several colon and breast cancer cell lines with different p53 status. PKR protein was activated by 5-FU treatment in a p53-independent manner,inducing phosphorylation of the protein synthesis translation initiation factor eIF-2alpha and cell death by apoptosis. Furthermore, PKR interference promoted a decreased response to 5-FU treatment and those cells were not affected by the synergistic antitumor activity of 5-FU/IFNalpha combination. These results, taken together, provide evidence that PKR is a key molecular target of 5-FU with potential relevance in the clinical use of this drug.

High ACSL5 transcript levels associate with systemic lupus erythematosus and apoptosis in Jurkat T lymphocytes and peripheral blood cells

BACKGROUND: Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease in which increased apoptosis and decreased apoptotic cells removal has been described as most relevant in the pathogenesis. Long-chain acyl-coenzyme A synthetases (ACSLs) have been involved in the immunological dysfunction of mouse models of lupus-like autoimmunity and apoptosis in different in vitro cell systems. The aim of this work was to assess among the ACSL isoforms the involvement of ACSL2, ACSL4 and ACSL5 in SLE pathogenesis. FINDINGS: With this end, we determined the ACSL2, ACSL4 and ACSL5 transcript levels in peripheral blood mononuclear cells (PBMCs) of 45 SLE patients and 49 healthy controls by quantitative real time-PCR (q-PCR). We found that patients with SLE had higher ACSL5 transcript levels than healthy controls [median (range), healthy controls =16.5 (12.3-18.0) vs. SLE = 26.5 (17.8-41.7), P = 3.9x10 E-5] but no differences were found for ACSL2 and ACSL4. In in vitro experiments, ACSL5 mRNA expression was greatly increased when inducing apoptosis in Jurkat T cells and PBMCs by Phorbol-Myristate-Acetate plus Ionomycin (PMA+Io). On the other hand, short interference RNA (siRNA)-mediated silencing of ACSL5 decreased induced apoptosis in Jurkat T cells up to the control levels as well as decreased mRNA expression of FAS, FASLG and TNF. CONCLUSIONS: These findings indicate that ACSL5 may play a role in the apoptosis that takes place in SLE. Our results point to ACSL5 as a potential novel functional marker of pathogenesis and a possible therapeutic target in SLE

REPETIDO_A new extract of the plant calendula officinalis produces a dual in vitro effect: cytotoxic anti-tumor activity and lymphocyte activation

BACKGROUND Phytopharmacological studies of different Calendula extracts have shown anti-inflammatory, anti-viral and anti-genotoxic properties of therapeutic interest. In this study, we evaluated the in vitro cytotoxic anti-tumor and immunomodulatory activities and in vivo anti-tumor effect of Laser Activated Calendula Extract (LACE), a novel extract of the plant Calendula Officinalis (Asteraceae). METHODS An aqueous extract of Calendula Officinalis was obtained by a novel extraction method in order to measure its anti-tumor and immunomodulatory activities in vitro. Tumor cell lines derived from leukemias, melanomas, fibrosarcomas and cancers of breast, prostate, cervix, lung, pancreas and colorectal were used and tumor cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of LACE on human peripheral blood lymphocyte (PBL) proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in LACE-treated cells. In vivo anti-tumor activity was evaluated in nude mice bearing subcutaneously human Ando-2 melanoma cells. RESULTS The LACE extract showed a potent in vitro inhibition of tumor cell proliferation when tested on a wide variety of human and murine tumor cell lines. The inhibition ranged from 70 to 100%. Mechanisms of inhibition were identified as cell cycle arrest in G0/G1 phase and Caspase-3-induced apoptosis. Interestingly, the same extract showed an opposite effect when tested on PBLs and NKL cell line, in which in vitro induction of proliferation and activation of these cells was observed. The intraperitoneal injection or oral administration of LACE extract in nude mice inhibits in vivo tumor growth of Ando-2 melanoma cells and prolongs the survival day of the mice. CONCLUSION These results indicate that LACE aqueous extract has two complementary activities in vitro with potential anti-tumor therapeutic effect: cytotoxic tumor cell activity and lymphocyte activation. The LACE extract presented in vivo anti-tumoral activity in nude mice against tumor growth of Ando-2 melanoma cells.

A new extract of the plant Calendula officinalis produces a dual in vitro effect: cytotoxic anti-tumor activity and lymphocyte activation

BACKGROUND Phytopharmacological studies of different Calendula extracts have shown anti-inflammatory, anti-viral and anti-genotoxic properties of therapeutic interest. In this study, we evaluated the in vitro cytotoxic anti-tumor and immunomodulatory activities and in vivo anti-tumor effect of Laser Activated Calendula Extract (LACE), a novel extract of the plant Calendula Officinalis (Asteraceae). METHODS An aqueous extract of Calendula Officinalis was obtained by a novel extraction method in order to measure its anti-tumor and immunomodulatory activities in vitro. Tumor cell lines derived from leukemias, melanomas, fibrosarcomas and cancers of breast, prostate, cervix, lung, pancreas and colorectal were used and tumor cell proliferation in vitro was measured by BrdU incorporation and viable cell count. Effect of LACE on human peripheral blood lymphocyte (PBL) proliferation in vitro was also analyzed. Studies of cell cycle and apoptosis were performed in LACE-treated cells. In vivo anti-tumor activity was evaluated in nude mice bearing subcutaneously human Ando-2 melanoma cells. RESULTS The LACE extract showed a potent in vitro inhibition of tumor cell proliferation when tested on a wide variety of human and murine tumor cell lines. The inhibition ranged from 70 to 100%. Mechanisms of inhibition were identified as cell cycle arrest in G0/G1 phase and Caspase-3-induced apoptosis. Interestingly, the same extract showed an opposite effect when tested on PBLs and NKL cell line, in which in vitro induction of proliferation and activation of these cells was observed. The intraperitoneal injection or oral administration of LACE extract in nude mice inhibits in vivo tumor growth of Ando-2 melanoma cells and prolongs the survival day of the mice. CONCLUSION These results indicate that LACE aqueous extract has two complementary activities in vitro with potential anti-tumor therapeutic effect: cytotoxic tumor cell activity and lymphocyte activation. The LACE extract presented in vivo anti-tumoral activity in nude mice against tumor growth of Ando-2 melanoma cells.

Efecto del phlebodium decumanum y de la coenzima q10 sobre el rendimiento deportivo en jugadores profesionales de voleibol

INTRODUCTION: Physical training programmes are based on provoking transitory states of fatigue in order to induce super compensation by the biological systems involved in the activity, in order to improve the athlete's medium-long term performance. The administration of nutritional supplements with antioxidant and immunomodulatory properties, such as Phlebodium decumanum and coenzyme Q10, can be a very advantageous means of achieving recovery from the inflammation and tissue damage caused by the stress of prolonged, intense exercise. METHODOLOGY: An experimental, longitudinal, double- blind experiment was conducted, with three randomised groups obtained from a sample of 30 male volleyball players (aged 22-32 years) at the University of Granada, with a high level of training (17 hours a week during the 6 months preceding the study). The effects were then evaluated of a month-long physical training programme, common to all the study groups, associated with the simultaneous administration of the following nutritional supplements: Phlebodium decumanum (4 capsules of 400 mg/capsule, daily), Experimental Group 1; Phlebodium decumanum (same dose andchedule as Group 1) plus coenzyme Q10 (4 capsules of 30 mg/ capsule, daily), Experimental Group 2; a placebo substance, Control Group. The following dependent blood variables were examined to assess the effects of the intervention on the basal immune and endocrine-metabolic profile: cortisol and interleukin-6, both related to the axis of exercise-induced stress; and lactic acid and ammonium, related essentially to the anaerobic metabolism of energy. RESULTS: All the study groups presented favourable adaptive changes with respect to the endocrine-metabolic and immune profile, as reflected by a significant decrease in the post-test concentrations of cortisol, interleukin 6, lactic acid and ammonium, compared to the values recorded before the physical activity with/without nutritional supplement, per protocol. The groups that achieved the most favourable profile were those which had received nutritional supplementation, rather than the placebo, and among the former, those which had received the double- strength supplement with Phlebodium decumanum plus coenzyme Q10. CONCLUSIONS: The intake of Phlebodium decumanum plus coenzyme Q10 for 4 weeks produced protective effects on the endocrine-metabolic and immune profile, which we attribute to the immunomodulatory and antioxidant properties of these substances, which are highly beneficial not only in terms of delaying fatigue and improving athletic performance, but also in reducing the risk of injuries associated with high intensity exercise.

Regulation of cell death receptor S-nitrosylation and apoptotic signaling by Sorafenib in hepatoblastoma cells.

Nitric oxide (NO) plays a relevant role during cell death regulation in tumor cells. The overexpression of nitric oxide synthase type III (NOS-3) induces oxidative and nitrosative stress, p53 and cell death receptor expression and apoptosis in hepatoblastoma cells. S-nitrosylation of cell death receptor modulates apoptosis. Sorafenib is the unique recommended molecular-targeted drug for the treatment of patients with advanced hepatocellular carcinoma. The present study was addressed to elucidate the potential role of NO during Sorafenib-induced cell death in HepG2 cells. We determined the intra- and extracellular NO concentration, cell death receptor expression and their S-nitrosylation modifications, and apoptotic signaling in Sorafenib-treated HepG2 cells. The effect of NO donors on above parameters has also been determined. Sorafenib induced apoptosis in HepG2 cells. However, low concentration of the drug (10nM) increased cell death receptor expression, as well as caspase-8 and -9 activation, but without activation of downstream apoptotic markers. In contrast, Sorafenib (10µM) reduced upstream apoptotic parameters but increased caspase-3 activation and DNA fragmentation in HepG2 cells. The shift of cell death signaling pathway was associated with a reduction of S-nitrosylation of cell death receptors in Sorafenib-treated cells. The administration of NO donors increased S-nitrosylation of cell death receptors and overall induction of cell death markers in control and Sorafenib-treated cells. In conclusion, Sorafenib induced alteration of cell death receptor S-nitrosylation status which may have a relevant repercussion on cell death signaling in hepatoblastoma cells.