Aminoimidazole Carboxamide Ribonucleotide (AICAR) Inhibits the Growth of Retinoblastoma In Vivo by Decreasing Angiogenesis and Inducing Apoptosis

5-Aminoimidazole-4-carboxamide-1-β-4-ribofuranoside (AICAR), an analog of AMP is widely used as an activator of AMP-kinase (AMPK), a protein that regulates the responses of the cell to energy change. Recently, we showed that AICAR-induced AMPK activation inhibits the growth of retinoblastoma cells in vitro by decreasing cyclins and by inducing apoptosis and S-phase arrest. In this study, we investigated the effects of AMPK activator AICAR on the growth of retinoblastoma in vivo. Intraperitoneal injection of AICAR resulted in 48% growth inhibition of Y79 retinoblastoma cell tumors in mice. Tumors isolated from mice treated with AICAR had decreased expression of Ki67 and increased apoptotic cells (TUNEL positive) compared with the control. In addition, AICAR treatment suppressed significantly tumor vessel density and macrophage infiltration. We also showed that AICAR administration resulted in AMPK activation and mTOR pathway inhibition. Paradoxically observed down-regulation of p21, which indicates that p21 may have a novel function of an oncogene in retinoblastoma tumor. Our results indicate that AICAR treatment inhibited the growth of retinoblastoma tumor in vivo via AMPK/mTORC1 pathway and by apoptogenic, anti-proliferative, anti-angiogenesis mechanism. AICAR is a promising novel non-chemotherapeutic drug that may be effective as an adjuvant in treating Retinoblastoma.     

Cytokine soluble receptors in perinatal and early neonatal life

BACKGROUND: In contrast to cellular receptors, soluble receptors do not enhance the cellular activation because they do not have transmembranic and cytoplasmic parts, acting thereby as endogenous regulatory mechanisms against systemic functions of cytokines. AIM: To measure serum concentrations of the soluble interleukin-2 receptor (sIL2R), soluble interleukin-4 receptor (sIL4R), soluble interleukin-6 receptor (sIL6R), and soluble tumor necrosis factor-alpha receptor I and soluble tumor necrosis factor-alpha receptor II, during the perinatal and early neonatal period, in order to evaluate their role in activation of immune response in labor and the first days postpartum. METHODS: Soluble receptor serum concentrations were determined by enzyme-linked immunosorbent assay, in 45 healthy, full-termed neonates during the first and fifth days after birth, in 25 of their mothers (MS), in 25 samples of umbilical cords (UC) and in 25 healthy adult donors age-matched with the mothers (controls). RESULTS: Soluble receptor serum concentrations showed considerable changes during labor and early neonatal life, being significantly higher both in MS (except sIL6R) and in neonatal sample UC, first and fifth days after birth, compared with controls (p<0.0001). Neonatal serum sIL2R and sIL6R increased significantly from birth to the fifth day, while the remaining receptors showed a rapid increase in the first day (p<0.0001), declining significantly thereafter (p<0.0001). CONCLUSION: Our findings suggest that the elevated concentrations of all studied soluble cytokine receptors reflect the activation of immune response, and represent also regulatory protective mechanisms for mother and fetus-neonate against the systemic function of cytokines during labor and early neonatal life.     

Deep diving in the blood stem cell‐ome

Defining the functional distinctions between cells comprising the bone marrow has yielded fundamental insights into lineage ordering and drivers of blood cell production. A novel, highly granular and multi‐dimensional molecular characterization of functional subsets of hematopoietic stem‐ and progenitor cells recently published in Cell Stem Cell (Cabezas‐Wallscheid et al, 2014 ) will serve as a landmark and treasure trove for unanticipated insights into basic biology and the development of future targeted medicine.     

Taste Discrimination Using Alternative Solvents for PTC and NaCl

Better discrimination was possible between threshold PTC solutionsand pure solvent when the solvent was a tasteless, low concentrationNaCl solution to which the subject had adapted, than when thesolvent was purified water. The reverse was true for thresholdNaCl stimuli. Subjective reports indicated this to be due tothe absence or presence of taste cues from the solvent and stimulusafter-effects. Interstimulus rinsing with the appropriate solventimproved discrimination. Chem. Senses 20: 299–304, 1995.     

Inhibition of ozone-induced SP-A oxidation by plant polyphenols

Surfactant protein-A (SP-A) is the best studied and most abundant of the protein components of lung surfactant and plays an important role in host defense of the lung. It has been shown that ozone-induced oxidation of SP-A protein changes its functional and biochemical properties. In the present study, eight plant polyphenols (three flavonoids, three hydroxycinnamic acids, and two hydroxybenzoic acids) known as strong antioxidants, were tested for their ability to inhibit ozone-induced SP-A oxidation as a mechanism for chemoprevention against lung damage. SP-A isolated from alveolar proteinosis patients was exposed to ozone (1 ppm) for 4 h. The flavonoids protected SP-A from oxidation in a dose dependent manner. ( - )-Epicatechin was the most potent flavonoid and exhibited inhibition of ozone-induced formation of carbonyls by 35% at a concentration as low as 5 μM. Hydroxybenzoic acids inhibited SP-A oxidation in a dose-dependent manner although they were less potent than flavonoids. On the other hand, hydroxycinnamic acids exhibited a different inhibitory pattern. Inhibition was observed only at medium concentrations. The results indicate that inhibition of SP-A oxidation by plant polyphenols may be a mechanism accounting for the protective activity of natural antioxidants against the effects of ozone exposure on lungs.     

On the bioreactivity of triorganotin aminobenzoates. Investigation of trialkyl and triarylyltin(IV) esters of 3-amino and 4-aminobenzoic acids

The synthesis and study of trimethyl-, tributyl- and triphenyltin esters of the 3- and 4-aminobenzoic acids are reported. The triorganotin derivatives are characterized by elemental analyses, FT-IR and solution ¹H and ¹³C NMR spectra. The structure of the trimethyltin 4-aminobenzoate is solved by X-ray diffraction and proves to be polymeric in nature with bridging carboxylates and trigonal bipyramidal tin(IV) environment. However, all the compounds become monomeric in solution with a tetrahedral tin coordination environment in chloroform and trigonal bipyramidal in DMSO due to coordination of the solvent as the NMR spectra have revealed. The compounds exhibit variable cytotoxic activity when tested against Κ562 myelogenous leukaemia, HeLa cervical cancer and HepG2 hepatocellular carcinoma cell lines, with the butyl derivatives being the more effective and the methyl ones the less. Interestingly, their antibacterial action was significantly lower when tested against Escherichia coli, while not appreciable direct interaction with DNA has been observed. The above observations account for a mode of action that may be related to their potential interaction with cell membranes and the subsequent inhibition of various signaling processes.