Evidence for embryonic stem-like signature and epithelial-mesenchymal transition features in the spheroid cells derived from lung adenocarcinoma.

Identification of the cellular and molecular aspects of lung cancer stem cells (LCSCs) that are suggested to be the main culprit of tumor initiation, maintenance, drug resistance, and relapse is a prerequisite for targeted therapy of lung cancer. In the current study, LCSCs subpopulation of A549 cells was enriched, and after characterization of the spheroid cells, complementary DNA (cDNA) microarray analysis was applied to identify differentially expressed genes (DEGs) between the spheroid and parental cells. Microarray results were validated using quantitative real-time reverse transcription-PCR (qRT-PCR), flow cytometry, and western blotting. Our results showed that spheroid cells had higher clonogenic potential, up-regulation of stemness gene Sox2, loss of CD44 expression, and gain of CD24 expression compared to parental cells. Among a total of 160 genes that were differentially expressed between the spheroid cells and the parental cells, 104 genes were up-regulated and 56 genes were down-regulated. Analysis of cDNA microarray revealed an embryonic stem cell-like signature and over-expression of epithelial-mesenchymal transition (EMT)-associated genes in the spheroid cells. cDNA microarray results were validated at the gene expression level using qRT-PCR, and further validation was performed at the protein level by flow cytometry and western blotting. The embryonic stem cell-like signature in the spheroid cells supports two important notions: maintenance of CSCs phenotype by dedifferentiating mechanisms activated through oncogenic pathways and the origination of CSCs from embryonic stem cells (ESCs). PI3/AKT3, as the most common up-regulated pathway, and other pathways related to aggressive tumor behavior and EMT process can confer to the spheroid cells' high potential for metastasis and distant seeding.

Seizure susceptibility alteration following reversible cholestasis in mice: Modulation by opioids and nitric oxide.

There is an increasing body of evidence that the central nervous system is affected by cholestatic liver disorders. Cholestasis has been shown to result in a decreased seizure propensity which is believed to be mediated by an increased opioidergic tone and nitric oxide (NO) signaling pathway. In this study, we used a reversible chemically-induced cholestasis model in mice to investigate the changes in seizure susceptibility. The cholestasis was induced by intragastric administration of alpha-naphthylisothiocyanate (ANIT) (100 mg/kg) or vehicle (corn oil). The threshold to generalized clonic seizures induced by timed intravenous infusion of pentylenetetrazole (PTZ) was used as an index of seizure propensity. The role of opioid receptors and NO pathway in the changes of seizure threshold, and the responsiveness to the anticonvulsant effect of opioid agonist, morphine, during and after the resolution of cholestasis was studied in this reversible paradigm of cholestatic disease. A significant increase in cholestasis-related biochemical markers as well as in clonic seizure threshold was observed; it was maximal at day 3 after cholestasis induction and slowly decreased to normal thereafter. Seizure threshold rise was inhibited by chronic administration of the opioid antagonist naltrexone or acute administration of N-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO production. Co-administration of subeffective doses of L-NAME and naltrexone showed an additive effect. Injection of an anticonvulsant dose of morphine on day 7 after cholestasis induction did not increase seizure threshold, suggestive of a downregulation of receptors even after cholestasis resolution. These data shows that ANIT-induced cholestasis leads to a reversible increased resistance to PTZ-induced seizures through an opioid/NO-mediated pathway, and is probably accompanied by downregulation of opioid receptors.

Zinc deficiency aggravates abnormal glucose metabolism in thalassemia major patients.

BACKGROUND: The aim was to determine whether reduced serum zinc level has a contributory effect on impairment of insulin secretion in beta-thalassemic patients with transfusion-induced iron overload. MATERIAL/METHODS: Seventy thalassemia patients who received deferoxamine chelation therapy and 69 healthy individuals as the control group were evaluated. A standard oral glucose tolerance test (OGTT) was performed and blood samples for measurement of serum ferritin, zinc, and insulin concentrations were obtained. RESULTS: Although the fasting serum insulin concentrations were quite similar between the patient and the control groups, serum insulin levels were significantly lower in the thalassemia patients one hour and two hours after oral glucose load ingestion compared with the healthy controls. Among the thalassemic adults, zinc deficiency (present in 37% of patients) resulted in significantly lower fasting and 1-hour post-OGTT serum insulin concentrations. The serum zinc level in patients with impaired OGTT was also considerably lower than in patients with normal OGTT. CONCLUSIONS: These data support the assumption that zinc deficiency might lead to an exacerbation of the inability of the pancreas to secrete sufficient amounts of insulin in response to glucose stimulation in beta-thalassemia patients. We suggest that serum zinc levels be routinely monitored in these patients as it might provide useful complementaly information regarding glucose metabolism.