ANTIOXIDANT AND ANTIPROLIFERATIVE POTENTIALS OF MARINE ACTINOMYCETES

Objective: The aim of present studyis to isolate and characterize a novel actinomycetes strain from marine sediments collected at Kakinada coast. To evaluate antioxidant and antiproliferative activities of the crude methanolic extract of isolated actinomycetes.Methods: Actinomycetes was isolated from marine sediments collected at Kakinada coast using starch casein agar. Morphological, biochemical and molecular characterization was performed and the crude methanolic extract was used for determination of in vitro antioxidant activity and antiproliferative activity against MDA-MB 231 breast cancer cells.Results: The crude methanolic extract exhibited significant antioxidant activity with IC­50­ value in the range of 30-46 µg/ml in different radical scavenging assays. Moreover, the extract showed concentration dependent cytotoxicity against triple negative breast cancer cell line, MDA-MB 231 with IC50 of 42.5µg/ml. The extract also inhibited cell proliferation with IC50 value 44.1 µg/ml probably by arresting cell cycle at S phase. The antioxidant activity of the extract was strongly correlated with cytotoxic and antiproliferative activity.Conclusion: The isolated marine actinomycetes can be the potential source of antioxidants with the anticancer property

Localization of uPAR and MMP-9 in lipid rafts is critical for migration, invasion and angiogenesis in human breast cancer cells

<p>Abstract</p> <p>Background</p> <p>uPAR and MMP-9, which play critical roles in tumor cell invasion, migration and angiogenesis, have been shown to be associated with lipid rafts.</p> <p>Methods</p> <p>To investigate whether cholesterol could regulate uPAR and MMP-9 in breast carcinoma, we used MβCD (methyl beta cyclodextrin, which extracts cholesterol from lipid rafts) to disrupt lipid rafts and studied its effect on breast cancer cell migration, invasion, angiogenesis and signaling.</p> <p>Results</p> <p>Morphological evidence showed the association of uPAR with lipid rafts in breast carcinoma cells. MβCD treatment significantly reduced the colocalization of uPAR and MMP-9 with lipid raft markers and also significantly reduced uPAR and MMP-9 at both the protein and mRNA levels. Spheroid migration and invasion assays showed inhibition of breast carcinoma cell migration and invasion after MβCD treatment. <it>In vitro </it>angiogenesis studies showed a significant decrease in the angiogenic potential of cells pretreated with MβCD. MβCD treatment significantly reduced the levels of MMP-9 and uPAR in raft fractions of MDA-MB-231 and ZR 751 cells. Phosphorylated forms of Src, FAK, Cav, Akt and ERK were significantly inhibited upon MβCD treatment. Increased levels of soluble uPAR were observed upon MβCD treatment. Cholesterol supplementation restored uPAR expression to basal levels in breast carcinoma cell lines. Increased colocalization of uPAR with the lysosomal marker LAMP1 was observed in MβCD-treated cells when compared with untreated cells.</p> <p>Conclusion</p> <p>Taken together, our results suggest that cholesterol levels in lipid rafts are critical for the migration, invasion, and angiogenesis of breast carcinoma cells and could be a critical regulatory factor in these cancer cell processes mediated by uPAR and MMP-9.</p

Co-Depletion of Cathepsin B and uPAR Induces G0/G1 Arrest in Glioma via FOXO3a Mediated p27Kip1 Upregulation

Cathepsin B and urokinase plasminogen activator receptor (uPAR) are both known to be overexpressed in gliomas. Our previous work and that of others strongly suggest a relationship between the infiltrative phenotype of glioma and the expression of cathepsin B and uPAR. Though their role in migration and adhesion are well studied the effect of these molecules on cell cycle progression has not been thoroughly examined.Cathepsin B and uPAR single and bicistronic siRNA plasmids were used to downregulate these molecules in SNB19 and U251 glioma cells. FACS analysis and BrdU incorporation assay demonstrated G0/G1 arrest and decreased proliferation with the treatments, respectively. Immunoblot and immunocyto analysis demonstrated increased expression of p27(Kip1) and its nuclear localization with the knockdown of cathepsin B and uPAR. These effects could be mediated by alphaVbeta3/PI3K/AKT/FOXO pathway as observed by the decreased alphaVbeta3 expression, PI3K and AKT phosphorylation accompanied by elevated FOXO3a levels. These results were further confirmed with the increased expression of p27(Kip1) and FOXO3a when treated with Ly294002 (10 microM) and increased luciferase expression with the siRNA and Ly294002 treatments when the FOXO binding promoter region of p27(Kip1) was used. Our treatment also reduced the expression of cyclin D1, cyclin D2, p-Rb and cyclin E while the expression of Cdk2 was unaffected. Of note, the Cdk2-cyclin E complex formation was reduced significantly.Our study indicates that cathepsin B and uPAR knockdown induces G0/G1 arrest by modulating the PI3K/AKT signaling pathway and further increases expression of p27(Kip1) accompanied by the binding of FOXO3a to its promoter. Taken together, our findings provide molecular mechanism for the G0/G1 arrest induced by the downregulation of cathepsin B and uPAR in SNB19 and U251 glioma cells

Synthesis of (±) Fredericamycin A

The synthesis of Fredericamycin A (1) has been achieved by subjecting the 1,3-dione (14) to an unusual 5-trigonal radical cyclization followed by reductive elimination of the halogen in 15 and subsequent demethylation

Regioselective free radical cyclization: a general method for the synthesis of the spiro[4.4]nonane system of fredericamycin A

Introduction of a halogen atom at the middle carbon atom of cyclic 1,3-diketones is described. A convenient approach for constructing the spiro[4.4]nonane system of fredericamycin A has been demonstrated by halogen transfer during radical cyclization followed by reductive elimination of the halogen atom. The configuration of the bromo compound 6b was confirmed by X-ray crystal structure analysis

Chemical investigation of the marine sponges <i style="">Clathria reinwardti</i> and <i style="">Haliclona cribricutis</i>

607-610Diethylene glycol dibenzoate (DEGDB) (1) and two fenvalerate isomers (4 and 5) have been isolated from the sponges Clathria reinwardti and Haliclona cribricutis respectively. Two other diethylene glycol esters (2 and 3) are also synthesized. The structures of the compounds have been established by means of spectroscopic analysis, optical rotations and comparison with known compounds. These compounds are evaluated for their antimicrobial and pesticidal activities

Role of surrogate risk biomarkers for cardiovascular risk prediction in chronic kidney patients

Background: Biomarkers are quantifiable and repeatable biological indicators and some of them are used to predict cardiovascular events in individuals with chronic renal illness. Objectives: To assess, surrogate risk biomarkers like H-FABP, CIMT, serum albumin and A/C ratio in development of cardiovascular disease in stage III and stage IV CKD patients. Methods: It is a case control study, with sample size each of hundred cases and controls who were recruited from Nephrology department and present with chronic kidney disease – stage III / IV. B-model ultrasonography was employed for CIMT evaluation. H-FABP would be estimated using ELISA. Serum albumin in blood samples was determined using the bromocresol green. Urinary Albumin/creatinine ratio was expressed as milligram of albumin excreted per gram of urinary creatinine. Results: It was found that, there was a mean increase in the values of H-FABP and CIMT for cases compared to control population. However there was no much increase in mean values for serum albumin to control and case population. Conclusion: use of established and significant laboratory biomarkers like H-FABP, CIMT, ACR, Serum albumin concentration were really proven to be assessing the CKD risk in the general population