Antioxidant Intake and Antitumor Therapy: Toward Nutritional Recommendations for Optimal Results

This study was supported by the Regional Government of Andalusia (Project P11-CTS-7651 and assistance to the CTS-107 group).The role of the induction of oxidative stress as the mechanism of action of many antitumor drugs is acquiring an increasing interest. In such cases, the antitumor therapy success may be conditioned by the antioxidants present in our own body, which can be synthesized de novo (endogenous) or incorporated through the diet and nutritional supplements (exogenous). In this paper, we have reviewed different aspects of antioxidants, including their classification, natural sources, importance in diet, consumption of nutritional supplements, and the impact of antioxidants on health. Moreover, we have focused especially on the study of the interaction between antioxidants and antitumor therapy, considering both radiotherapy and chemotherapy. In this regard, we found that the convenience of administration of antioxidants during cancer treatment still remains a very controversial issue. In general terms, antioxidants could promote or suppress the effectiveness of antitumor treatment and even protect healthy tissues against damage induced by oxidative stress. The effects may depend on many factors discussed in the paper. These factors should be taken into consideration in order to achieve precise nutritional recommendations for patients. The evidence at the moment suggests that the supplementation or restriction of exogenous antioxidants during cancer treatment, as appropriate, could contribute to improving its efficiency.Junta de Andalucia P11-CTS-765

Cell surface immobilization of GABAARs in cerebellar granule cells depends on the M3/M4 cytoplasmatic loop of the alpha 1 subunit

Gamma-Aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the vertebrate brain. The localization of GABA receptors type A (GABAARs) at strategically located domains of the neuronal membrane is of vital importance for fast inhibitory synapse transmission efficacy. We have shown before that the lateral mobility of GABAARs depends on subunit composition of the complex. To study the lateral mobility of GABAARs in living, cultured neurons, we transfected cerebellar granule cells with either the complete 1 GABAAR subunit or with a truncation of the 1 subunit that lacks the major intracellular loop (M3/M4). We examined the location and lateral mobility of receptors containing both versions of the 1 subunit in living neurons. From fluorescence recovery after photobleaching experiments we present novel evidences that the intracellular M3/M4 loop of the 1 subunit restricts the lateral mobility of GABAARs when expressed in neurons. In addition, our immunocytochemical studies suggested that receptors containing the truncated subunit seem to be unable to reach synaptic localizations. Here we show for the first time that the 1 intracellular loop (M3/M4) domain has a relevant role in controlling the lateral mobility of GABAARs in neurons, and we believe that this is a novel and important contribution in neurobiology of GABAA receptors

Ultrastructural and molecular analyzes of insulin-producing cells induced from human hepatoma cells.

Background aims. Diabetes type I is an autoimmune disease characterized by the destruction of pancreatic insulin-producing (beta-) cells and resulting in external insulin dependence for life. Islet transplantation represents a potential treatment for diabetes but there is currently a shortage of suitable organs donors. To augment the supply of donors, different strategies are required to provide a potential source of beta-cells. These sources include embryonic and adult stem cells as well as differentiated cell types. The main goal of this study was to induce the transdifferentiation (or conversion of one type cell to another) of human hepatoma cells (HepG2 cells) to insulin-expressing cells based on the exposure of HepG2 cells to an extract of rat insulinoma cells (RIN). Methods. HepG2 cells were fi rst transiently permeabilized with Streptolysin O and then exposed to a cell extract obtained from RIN cells. Following transient exposure to the RIN extract, the HepG2 cells were cultured for 3 weeks. Results. Acquisition of the insulin-producing cell phenotype was determined on the basis of (i) morphologic and (ii) ultrastructural observations, (iii) immunologic detection and (iv) reverse transcription (RT)- polymerase chain reaction (PCR) analysis. Conclusions. This study supports the use of cell extract as a feasible method for achieve transdifferentiation of hepatic cells to insulin-producing cells

5-Fluorouracil-loaded poly(ε-caprolactone) nanoparticles combined with phage E gene therapy as a new strategy against colon cancer

This work aimed to develop a new therapeutic approach to increase the efficacy of 5-fluorouracil (5-FU) in the treatment of advanced or recurrent colon cancer. 5-FU-loaded biodegradable poly(ε-caprolactone) nanoparticles (PCL NPs) were combined with the cytotoxic suicide gene E (combined therapy). The SW480 human cancer cell line was used to assay the combined therapeutic strategy. This cell line was established from a primary adenocarcinoma of the colon and is characterized by an intrinsically high resistance to apoptosis that correlates with its resistance to 5-FU. 5-FU was absorbed into the matrix of the PCL NPs during synthesis using the interfacial polymer disposition method. The antitumor activity of gene E from the phage ϕX174 was tested by generating a stable clone (SW480/12/E). In addition, the localization of E protein and its activity in mitochondria were analyzed. We found that the incorporation of 5-FU into PCL NPs (which show no cytotoxicity alone), significantly improved the drug’s anticancer activity, reducing the proliferation rate of colon cancer cells by up to 40-fold when compared with the nonincorporated drug alone. Furthermore, E gene expression sensitized colon cancer cells to the cytotoxic action of the 5-FU-based nanomedicine. Our findings demonstrate that despite the inherent resistance of SW480 to apoptosis, E gene activity is mediated by an apoptotic phenomenon that includes modulation of caspase-9 and caspase-3 expression and intense mitochondrial damage. Finally, a strongly synergistic antiproliferative effect was observed in colon cancer cells when E gene expression was combined with the activity of the 5-FU-loaded PCL NPs, thereby indicating the potential therapeutic value of the combined therapy

gef Gene Expression in MCF-7 Breast Cancer Cells is Associated with a Better Prognosis and Induction of Apoptosis by p53-Mediated Signaling Pathway

Breast cancer research has developed rapidly in the past few decades, leading to longer survival times for patients and opening up the possibility of developing curative treatments for advanced breast cancer. Our increasing knowledge of the biological pathways associated with the progression and development of breast cancer, alongside the failure of conventional treatments, has prompted us to explore gene therapy as an alternative therapeutic strategy. We previously reported that gef gene from E. coli has shown considerable cytotoxic effects in breast cancer cells. However, its action mechanism has not been elucidated. Indirect immunofluorescence technique using flow cytometry and immunocytochemical analysis were used to detect breast cancer markers: estrogen (ER) and progesterone (PR) hormonal receptors, human epidermal growth factor receptor-2 proto-oncogene (c-erbB-2), ki-67 antigen and p53 protein. gef gene induces an increase in ER and PR expressions and a decrease in ki-67 and c-erbB-2 gene expressions, indicating a better prognosis and response to treatment and a longer disease-free interval and survival. It also increased p53 expression, suggesting that gef-induced apoptosis is regulated by a p53-mediated signaling pathway. These findings support the hypothesis that the gef gene offers a new approach to gene therapy in breast cancer

Antioxidant Intake and Antitumor Therapy: Toward Nutritional Recommendations for Optimal Results

The role of the induction of oxidative stress as the mechanism of action of many antitumor drugs is acquiring an increasing interest. In such cases, the antitumor therapy success may be conditioned by the antioxidants present in our own body, which can be synthesized de novo (endogenous) or incorporated through the diet and nutritional supplements (exogenous). In this paper, we have reviewed different aspects of antioxidants, including their classification, natural sources, importance in diet, consumption of nutritional supplements, and the impact of antioxidants on health. Moreover, we have focused especially on the study of the interaction between antioxidants and antitumor therapy, considering both radiotherapy and chemotherapy. In this regard, we found that the convenience of administration of antioxidants during cancer treatment still remains a very controversial issue. In general terms, antioxidants could promote or suppress the effectiveness of antitumor treatment and even protect healthy tissues against damage induced by oxidative stress. The effects may depend on many factors discussed in the paper. These factors should be taken into consideration in order to achieve precise nutritional recommendations for patients. The evidence at the moment suggests that the supplementation or restriction of exogenous antioxidants during cancer treatment, as appropriate, could contribute to improving its efficiency

Human cardiac tissue induces transdifferentiation of adult stem cells towards cardiomyocytes

Background aims. The goal was to induce the transdifferentiation (or conversion) of human adipose-derived stem cells to cardiomyocytes using an intracellular extract obtained from adult human heart tissue. Methods. Human adult stem cells from lipoaspirates were transiently permeabilized, exposed to human atrial extracts and allowed to recover in culture. Results. After 21 days, the cells acquired a cardiomyocyte phenotype, as demonstrated by morphologic changes (appearance of binucleate, striated cells and branching fi bers), immunofl uorescence detection of cardiac-specifi c markers (connexin-43, sarcomeric a-actinin, cardiac troponin I and T, and desmin) and the presence of cardiomyocyte-related genes analyzed by reverse transcription – polymerase chain reaction (cardiac myosin light chain 1, a -cardiac actin, cardiac troponin T and cardiac b -myosin). Conclusions. We have demonstrated for the fi rst time that adult cardiomyocytes obtained from human donors retain the capacity to induce cardiomyocyte differentiation of mesenchymal stromal cells. The use of autologous extracts for reprogramming adult stem cells may have potential therapeutic implications for treating heart disease.This study was supported by the Consejería de Salud (Junta de Andalucía) through project numbers PI-0384/2008 and TCRM 0014/2006. We are grateful to Dr J. C. Prados and Dra N. Rodríguez-Losada for their help and comments on the manuscript

Prognostic value of RT-PCR tyrosinase detection in peripheral blood of melanoma patients

Malignant melanoma (MM) prognosis has been related to tumour thickness and clinical stage and metastasis risk has been associated with presence of tumour cells in peripheral blood. The aim of this study was to determine the relationship between presence of tyrosinase in peripheral blood of MM patients and their clinical prognosis. Blood samples from 58 MM patients (stage I–IV) were analysed, using RT-PCR assay to detect tyrosinase mRNA. The results showed that positive RT-PCR assay for tyrosinase were significantly associated with clinical status and tumour thickness. After a median follow-up of 24 months, RT-PCR results were found to be significant correlated with recurrence (p < 0.05) and clinical stage III (p < 0.05). Separate analysis of stage III tumours to determine the prognostic value of tyrosinase presence in peripheral blood showed an overall 24-month survival rate of 70% in the RT-PCR negative group versus 10% in the positive group (p < 0.02). These results suggest that detection of circulating melanoma cells may be especially relevant in stage III patients, in whom RT-PCR positivity defines a subpopulation at high risk of recurrence.This study was supported by the Fondo de Investigación Sanitaria de la Seguridad Social (FIS), Spain through no. PI041372

Prognosis Relevance of Serum Cytokines in Pancreatic Cancer

The overall survival of patients with pancreatic ductal adenocarcinoma is extremely low. Although gemcitabine is the standard used chemotherapy for this disease, clinical outcomes do not reflect significant improvements, not even when combined with adjuvant treatments. There is an urgent need for prognosis markers to be found. The aim of this study was to analyze the potential value of serum cytokines to find a profile that can predict the clinical outcome in patients with pancreatic cancer and to establish a practical prognosis index that significantly predicts patients’ outcomes. We have conducted an extensive analysis of serum prognosis biomarkers using an antibody array comprising 507 human cytokines. Overall survival was estimated using the Kaplan-Meier method. Univariate and multivariate Cox’s proportional hazard models were used to analyze prognosis factors. To determine the extent that survival could be predicted based on this index, we used the leave-one-out cross-validation model. The multivariate model showed a better performance and it could represent a novel panel of serum cytokines that correlates to poor prognosis in pancreatic cancer. B7-1/CD80, EG-VEGF/PK1, IL-29, NRG1-beta1/HRG1-beta1, and PD-ECGF expressions portend a poor prognosis for patients with pancreatic cancer and these cytokines could represent novel therapeutic targets for this disease.The study was fully supported by ROCHE FARMA S.A (ref. H/OH-TAR-10/131 and ref. H/OH-TRR-08/59) and Instituto de Salud Carlos III (ISCIII) (Clinical trial ref. EC08/00009), and the Government of Andalusia Project P12-TIC-2082

Novel Drug Delivery System Based on Docetaxel-Loaded Nanocapsules as a Therapeutic Strategy Against Breast Cancer Cells

In the field of cancer therapy, lipid nanocapsules based on a core-shell structure are promising vehicles for the delivery of hydrophobic drugs such as docetaxel. The main aim of this work was to evaluate whether docetaxel-loaded lipid nanocapsules improved the anti-tumor effect of free docetaxel in breast cancer cells. Three docetaxel-loaded lipid nanocapsules were synthesized by solvent displacement method. Cytotoxic assays were evaluated in breast carcinoma (MCF-7) cells treated by the sulforhodamine B colorimetric method. Cell cycle was studied by flow cytometry and Annexin V-FITC, and apoptosis was evaluated by using propidium iodide assays. The anti-proliferative effect of docetaxel appeared much earlier when the drug was encapsulated in lipid nanoparticles than when it was free. Docetaxel-loaded lipid nanocapsules significantly enhanced the decrease in IC50 rate, and the treated cells evidenced apoptosis and a premature progression of the cell cycle from G(1) to G(2)-M phase. The chemotherapeutic effect of free docetaxel on breast cancer cells is improved by its encapsulation in lipid nanocapsules. This approach has the potential to overcome some major limitations of conventional chemotherapy and may be a promising strategy for future applications in breast cancer therapy