Vatica diospyroides Symington type LS Root Extract Induces Antiproliferation of KB, MCF-7 and NCI-H187 Cell Lines

Purpose: To investigate the therapeutic efficacy of V. diospyroides Symington type LS root extract as a chemopreventive agent against various cancer cell lines.Methods: Acetone root extract was evaluated for in vitro cytotoxicity against KB (oral cavity cancer), MCF-7 (breast cancer), and NCI-H187 (small cell lung cancer), using Resazurin microplate assay (REMA). Toxicity against a representative normal cells, Vero (African green monkey kidney), was assessed using green fluorescence protein (GFP)-based assay.Results: V. diospyroides root extract showed significant cytotoxic effects on KB and MCF-7 cell lines in a dose-dependent manner with IC50 of 35.05 ± 1.45 and 36.63 ± 3.40 μg/mL, respectively. NCI-H187 was not significantly inhibited (≤ 19.39 % inhibition) at the concentrations tested. IC50 against Vero cells was outside the concentration range of 0.2 - 50 μg/mL.Conclusion: These results indicate that the root extract of V. diospyroides has in vitro cytotoxic effect on human oral cavity cancer and breast cancer cells. No toxic effect on normal cells was observed. Thus, the extract may provide bioactive substances for human cancer therapy.Keywords: Breast cancer, Oral cavity cancer, Lung cancer, Cytotoxicity, Vero cells, Vatica diospyroide

Characterization of a Novel Binding Protein for Fortilin/TCTP — Component of a Defense Mechanism against Viral Infection in Penaeus monodon

The Fortilin (also known as TCTP) in Penaeus monodon (PmFortilin) and Fortilin Binding Protein 1 (FBP1) have recently been shown to interact and to offer protection against the widespread White Spot Syndrome Virus infection. However, the mechanism is yet unknown. We investigated this interaction in detail by a number of in silico and in vitro analyses, including prediction of a binding site between PmFortilin/FBP1 and docking simulations. The basis of the modeling analyses was well-conserved PmFortilin orthologs, containing a Ca2+-binding domain at residues 76–110 representing a section of the helical domain, the translationally controlled tumor protein signature 1 and 2 (TCTP_1, TCTP_2) at residues 45–55 and 123–145, respectively. We found the pairs Cys59 and Cys76 formed a disulfide bond in the C-terminus of FBP1, which is a common structural feature in many exported proteins and the “x–G–K–K” pattern of the amidation site at the end of the C-terminus. This coincided with our previous work, where we found the “x–P–P–x” patterns of an antiviral peptide also to be located in the C-terminus of FBP1. The combined bioinformatics and in vitro results indicate that FBP1 is a transmembrane protein and FBP1 interact with N-terminal region of PmFortilin

Cytotoxicity Screening of Plants of Genus Piper in Breast Cancer Cell Lines

Purpose: To examine whether seven species of plants of genus Piper possess anti-cancer effects.Methods: One normal breast and three breast cancer cell lines were used to test cytotoxic effects over a period of 72 h using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The dried plants were extracted with methanol and dichloromethane, and the effective extract isolated by crystallization, acid/base extraction and column chromatography techniques. Fragmented DNA was purified by phenol/chloroform/isoamyl alcohol.Results: Methanol and dichloromethane extracts of Piper retrofractum, Piper betle, especially Piper nigrum, exhibited strong effect on MDA-MB-468. When the crude extract of P. nigrum was then separated by column chromatography, fraction D showed activity against both MCF-7 and MDA-MB-468 cells. Fraction DE that was isolated from D demonstrated a highly cytotoxic effect with IC50 values of 8.33 ± 1.27 and 7.48 ± 0.57 μg/ml on MCF-7 and MDA-MB-468 cells, respectively. Furthermore, fraction DF exhibited a strong cytotoxic effect only on MCF-7 with IC50 value of 6.51 ± 0.39 μg/ml. DNA smears of MCF-7 and MDA-MB-468 cells treated with fraction DE and DF were observed within 7 days.Conclusions: These results indicate that the compounds isolated from P. nigrum, viz, DE and DF, have cytotoxic effect on breast cancer cell lines. These fractions could be promising agent for breast cancer treatment. Further studies on the isolation, structural and mechanism elucidation of the active compound are still needed being carried out.Keywords: Cytotoxicity, Breast cancer, P. nigrum, DNA fragmentatio

Fortilin potentiates the peroxidase activity of Peroxiredoxin-1 and protects against alcohol-induced liver damage in mice

Fortilin, a pro-survival molecule, inhibits p53-induced apoptosis by binding to the sequence-specific DNA-binding domain of the tumor suppressor protein and preventing it from transcriptionally activating Bax. Intriguingly, fortilin protects cells against ROS-induced cell death, independent of p53. The signaling pathway through which fortilin protects cells against ROS-induced cell death, however, is unknown. Here we report that fortilin physically interacts with the antioxidant enzyme peroxiredoxin-1 (PRX1), protects it from proteasome-mediated degradation, and keeps it enzymatically active by blocking its deactivating phosphorylation by Mst1, a serine/threonine kinase. At the whole animal level, the liver-specific overexpression of fortilin reduced PRX1 phosphorylation in the liver, enhanced PRX1 activity, and protected the transgenic animals against alcohol-induced, ROS-mediated, liver damage. These data suggest the presence of a novel oxidative-stress-handling pathway where the anti-p53 molecule fortilin augments the peroxidase PRX1 by protecting it against degradation and inactivation of the enzyme. Fortilin-PRX1 interaction in the liver could be clinically exploited further to prevent acute alcohol-induced liver damage in humans

TCTP protects from apoptotic cell death by antagonizing bax function

International audienceTranslationally controlled tumor protein (TCTP) is a potential target for cancer therapy. It functions as a growth regulating protein implicated in the TSC1-TSC2 -mTOR pathway or a guanine nucleotide dissociation inhibitor for the elongation factors EF1A and EF1Bbeta. Accumulating evidence indicates that TCTP also functions as an antiapoptotic protein, through a hitherto unknown mechanism. In keeping with this, we show here that loss of tctp expression in mice leads to increased spontaneous apoptosis during embryogenesis and causes lethality between E6.5 and E9.5. To gain further mechanistic insights into this apoptotic function, we solved and refined the crystal structure of human TCTP at 2.0 A resolution. We found a structural similarity between the H2-H3 helices of TCTP and the H5-H6 helices of Bax, which have been previously implicated in regulating the mitochondrial membrane permeability during apoptosis. By site-directed mutagenesis we establish the relevance of the H2-H3 helices in TCTP's antiapoptotic function. Finally, we show that TCTP antagonizes apoptosis by inserting into the mitochondrial membrane and inhibiting Bax dimerization. Together, these data therefore further confirm the antiapoptotic role of TCTP in vivo and provide new mechanistic insights into this key function of TCTP