The systemic administration of neural stem cells expressing an inducible and soluble form of growth arrest specific 1 inhibits mammary gland tumor growth and the formation of metastases.

BACKGROUND AIMS: Metastasis to different organs is the major cause of death in breast cancer patients. The poor clinical prognosis and lack of successful treatments for metastatic breast cancer patients demand the development of new tumor-selective therapies. Thus, it is necessary to develop treatments capable of releasing therapeutic agents to both primary tumors and metastases that avoid toxic side effects in normal tissue, and neural stem cells are an attractive vehicle for tracking tumor cells and delivering anti-cancer agents. The authorspreviously demonstrated that a soluble form of growth arrest specific 1 (GAS1) inhibits the growth of triple-negative breast tumors and glioblastoma. METHODS: In this study, the authors engineered ReNcell CX (EMD Millipore, Temecula, CA, USA) neural progenitor cells to express truncated GAS1 (tGAS1) under a tetracycline/on inducible system using lentiviral vectors. RESULTS: Here the authors show that treatment with ReNcell-tGAS1 in combination with tetracycline decreased primary tumor growth and inhibited the formation of metastases in tumor-bearing mice by diminishing the phosphorylation of AKT and ERK1/2 in orthotopic mammary gland tumors. Moreover, the authors observed that ReNcell-tGAS1 prolonged the survival of 4T1 tumor-bearing mice. CONCLUSIONS: These data suggest that the delivery of tGAS1 by ReNcell cells could be an effective adjuvant for the treatment of triple-negative breast cancer.

Simultaneous Treatment with Soluble Forms of GAS1 and PTEN Reduces Invasiveness and Induces Death of Pancreatic Cancer Cells.

INTRODUCTION: Pancreatic carcinoma cells exhibit a pronounced tendency to invade along and through intra and extrapancreatic nerves, even during the early stages of the disease, a phenomenon called perineural invasion (PNI). Thus, we sought to determine the effects of the simultaneous expression of soluble forms of GAS1 and PTEN (tGAS1 and PTEN-L) inhibiting tumor growth and invasiveness. MATERIALS AND METHODS: We employed a lentiviral system to simultaneously express tGAS1 and PTEN-L; in order to determine the effects of the treatments, cell viability and apoptosis as well as the expression of the transgenes by ELISA and intracellular signaling as ascertained by the activation of AKT and ERK1/2 were measured; cell invasiveness was determined using a Boyden chamber assay; and the effects of the treatment were measured in vivo in a mouse model. RESULTS: In the present work, we show that the combined treatment with tGAS1 and PTEN-L inhibits the growth of pancreatic cancer cells, by reducing the activities of both AKT and ERK 1/2, decreases cell invasiveness, and restrains tumor growth in a mouse model. CONCLUSION: The combined administration of tGAS1 and PTEN-L could be a valuable adjunct therapy for the treatment of pancreatic cancer.

The effect of finasteride and dutasteride on the synthesis of neurosteroids by glioblastoma cells.

Glioblastoma (GBM) is the most aggressive local brain tumor and effective treatments are lacking. Many studies have proposed an important participation of steroid hormones in the development of gliomas. Evidence was provided by statistics analysis where the incidence in adult population is 50% higher in men than in women. Female patients have a better prognosis for survival compared to male patients with GBM. Also, the expression of receptors to estrogen, progesterone and androgens in glioma cell lines and tumor biopsies, and glucocorticoid receptors in GBM cell lines had been reported. Here we have investigated the effect of the pharmacological inhibition of 5-α reductases on the capacity of GBM derived cell lines C6 (rat) and U87 (human) to synthesize neurosteroids. As the knowledge of the pathways used to synthesize neurosteroids by GBM derived cells was incomplete, we have investigated the synthesis of these steroids by C6 and U87 cells using tritiated precursors and thin layer chromatography (TLC). Increasing concentrations of finasteride and dutasteride were added to U87 culture media that was collected after 24 and 48 h. The results of the study showed that C6 cells incubated with 3H-cholesterol yielded dihydroandrosterone, hydroxytestosterone, androstenediol, androstenedione and estriol, while U87 cells also synthesized progesterone, and androstanedione. Incubation with 3H-androstenedione or 3H-testosterone mainly yielded dihydrotestosterone, androsterone, dihydroandrosterone, hydroxytestosterone, and estradiol in both lines. To note, we showed here for the first time that U87 cells synthesize corticosteroids. Addition of finasteride or dutasteride to U87 cells reduced androgen and estrogen synthesis. Dutasteride also decreased the synthesis of dihydrocorticosterone and allotetrahydrodesoxycorticosterone while deoxycorticosterone was accumulated. In summary, both GBM cell lines synthesize numerous neurosteroids, including 5-α reductase products and 3α-HSD pathways that were inhibited by finasteride and dutasteride. These inhibitors may be considered as tools to control neurosteroid synthesis of potential relevance for GBM survival.

Phospho-Tau Protein Expression in the Cell Cycle of SH-SY5Y Neuroblastoma Cells: A Morphological Study.

It has been reported that the main function of tau protein is to stabilize microtubules and promote the movement of organelles through the axon in neurons. In Alzheimer's disease, tau protein is the major constituent of the paired helical filament, and it undergoes post-translational modifications including hyperphosphorylation and truncation. Whether other functions of tau protein are involved in Alzheimer's disease is less clear. We used SH-SY5Y human neuroblastoma cells as an in vitro model to further study the functions of tau protein. We detected phosphorylated tau protein as small dense dots in the cell nucleus, which strongly colocalize with intranuclear speckle structures that were also labelled with an antibody to SC35, a protein involved in nuclear RNA splicing. We have shown further that tau protein, phosphorylated at the sites recognized by pT231, TG-3, and AD2 antibodies, is closely associated with cell division. Different functions may be characteristic of phosphorylation at specific sites. Our findings suggest that the presence of tau protein is involved in separation of sister chromatids in anaphase, and that tau protein also participates in maintaining the integrity of the DNA (pT231, prophase) and chromosomes during cell division (TG-3).

Participation of the anti-inflammatory and antioxidative activity of docosahexaenoic acid on indomethacin-induced gastric injury model.

Adverse gastrointestinal (GI) effects caused by nonsteroidal anti-inflammatory drugs (NSAIDs), including indomethacin, are recognized as the major limitation to their clinical use. NSAID-induced gastric damage is generated by cyclooxygenase inhibition, activation of inflammatory processes, and oxidative stress. Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid, has shown gastroprotective effects; however, the molecular mechanisms underlying these effects have not been fully explained. As a result, the aim of this study was to examine DHA's anti-inflammatory and antioxidative actions in a mouse model of indomethacin-induced gastric injury. Oral administration of DHA (3, 10, 30, and 100mg/kg) caused a reduction in indomethacin-induced gastric hemorrhagic lesions. We found that the gastroprotective effects of DHA treatment (100mg/kg) were accompanied by decreases in several parameters: in leukocyte recruitment; gastric levels of myeloperoxidase; leukotriene B4; intercellular adhesion molecule-1; tumor necrosis factor alpha; and nuclear translocation of nuclear factor-кB. Concurrently, we observed an improvement in antioxidant defenses produced by the increase in superoxide dismutase and glutathione activities but not catalase; in addition, a decrease in some oxidative damage markers such as malondialdehyde and carbonyl proteins in lipids and proteins was observed. Furthermore, resolvin D1 production and expression of free fatty acid receptor 4 were stimulated by DHA. Therefore, this study identified the antioxidant and anti-inflammatory actions of DHA as the main mechanisms involved in DHA's gastroprotective effects against indomethacin-induced gastric damage.

L-type calcium channel activation up-regulates the mRNAs for two different sodium channel alpha subunits (Nav1.2 and Nav1.3) in rat pituitary GH3 cells.

Calcium entry through L-type Ca2+ channels has been shown to increase the number of Na+ channels in GH3 cells, a clonal line of rat pituitary cells. To test whether this Ca2+ influx affects the levels of Na+ channel mRNAs, we first examined which Na+ channel subunits are expressed in GH3 cells. By using RT-PCR with specific primers, we detected transcripts for four alpha subunits (Nav1.1, Nav1.2, Nav1.3 and Nav1.6) and two auxiliary subunits (beta1 and beta3) of Na+ channels in total RNA from control GH3 cells. Next, we optimized the RT-PCR conditions to allow detection of cDNAs in the linear range of the assay. These conditions were then used to assess the transcript levels of Na+ channels after chronic exposure (72 h) of GH3 cells to the L-type Ca2+ channel blocker nimodipine (1 microM) or the L-type channel agonist Bay K 8644 (0.5 microM). Nimodipine treatment caused a moderate reduction (approximately 30%) of the mRNA for Nav1.2 and a marked reduction (approximately 70%) of the mRNA for Nav1.3, whereas treatment with Bay K 8644 produced 90-130% increases in these same mRNAs. There were no concomitant changes in the mRNAs for Nav1.1 and Nav1.6. Moreover, beta1 and beta3 mRNA levels were also unchanged. Thus, GH3 cells express multiple Na+ channel subunits and L-type Ca2+ channel activity up-regulates in a specific way the mRNAs for Nav1.2 and Nav1.3. These findings improve our knowledge on the molecular diversity of Na+ channels in pituitary cells and extend the actual view about the regulation of Na+ channel gene expression by Ca2+ influx.

Nerve growth factor affects Ca2+ currents via the p75 receptor to enhance prolactin mRNA levels in GH3 rat pituitary cells.

In clonal pituitary GH(3) cells, spontaneous action potentials drive the opening of Ca(v)1 (L-type) channels, leading to Ca(2+) transients that are coupled to prolactin gene transcription. Nerve growth factor (NGF) has been shown to stimulate prolactin synthesis by GH(3) cells, but the underlying mechanisms are unknown. Here we studied whether NGF influences prolactin gene expression and Ca(2+) currents. By using RT-PCR, NGF (50 ng ml(-1)) was found to augment prolactin mRNA levels by approximately 80% when applied to GH(3) cells for 3 days. A parallel change in the prolactin content was detected by Western blotting. Both NGF-induced responses were mimicked by an agonist (Bay K 8644) and prevented by a blocker (nimodipine) of L-type channels. In whole-cell patch-clamp experiments, NGF enhanced the L-type Ca(2+) current by approximately 2-fold within 60 min. This effect reversed quickly upon growth factor withdrawal, but was maintained for days in the continued presence of NGF. In addition, chronic treatment (>or= 24 h) with NGF amplified the T-type current, which flows through Ca(v)3 channels and is thought to support pacemaking activity. Thus, NGF probably increases the amount of Ca(2+) that enters per action potential and may also induce a late increase in spike frequency. MC192, a specific antibody for the p75 neurotrophin receptor, but not tyrosine kinase inhibitors (K252a and lavendustin A), blocked the effects of NGF on Ca(2+) currents. Overall, the results indicate that NGF activates the p75 receptor to cause a prolonged increase in Ca(2+) influx through L-type channels, which in turn up-regulates the prolactin mRNA.

Diferencias de género en el malestar psíquico de estudiantes universitarios / Gender differences in psychic distress in university students

Existen numerosos estudios que muestran que los trastornos mentales comunes son enfermedades frecuentes y discapacitantes. Se ha observado que los estudiantes universitarios constituyen un grupo de riesgo. El objetivo de esta investigación es estudiar la salud mental de estudiantes de la Universidad de Chile y las posibles variables asociadas a malestar psíquico. Se aplicó una encuesta estructurada-que incluía el Cuestionario de Salud de Goldberg, el APGAR familiar de Smilkenstein, y otras variables- a los alumnos de cuatro facultades que eran beneficiarios del Programa de Atención Económica (PAE). Resultados: del total de 1.704 alumnos se obtuvo una tasa de respuesta del 88,8por ciento, correspondiendo a 1.514 estudiantes; 54,5 por ciento eran mujeres y 45,6 por ciento hombres; la edad promedio fue 21,8 años (IC21,8-22,1); el ingreso familiar promedio fue 273.151 pesos (IC263.552-282.749); el tiempo promedio de traslado de la casa a la facultad era de 62,1 minutos (IC 60,6-63,6) el APGAR familiar promedio fue de 7,4 (IC7,3-7,5) y un 34,8 por ciento (IC32,4-37,3)tenía un puntaje positivo para malestar psíquico. El malestar psíquico se asoció en forma significativa a ser mujer y a tener una disfunción familiar según APGAR familiar. Se comentan los resultados y la importancia de estos trabajos.