Anti-cancer potential of synergistic phytochemical combinations is influenced by the genetic profile of prostate cancer cell lines

Introduction: Despite strong epidemiological evidence that dietary factors modulate cancer risk, cancer control through dietary intervention has been a largely intractable goal for over sixty years. The effect of tumour genotype on synergy is largely unexplored. Methods: The effect of seven dietary phytochemicals, quercetin (0–100 μM), curcumin (0–80 μM), genistein, indole-3-carbinol (I3C), equol, resveratrol and epigallocatechin gallate (EGCG) (each 0–200 μM), alone and in all paired combinations om cell viability of the androgen-responsive, pTEN-null (LNCaP), androgen-independent, pTEN-null (PC-3) or androgen-independent, pTEN-positive (DU145) prostate cancer (PCa) cell lines was determined using a high throughput alamarBlue® assay. Synergy, additivity and antagonism were modelled using Bliss additivism and highest single agent equations. Patterns of maximum synergy were identified by polygonogram analysis. Network pharmacology approaches were used to identify interactions with known PCa protein targets. Results: Synergy was observed with all combinations. In LNCaP and PC-3 cells, I3C mediated maximum synergy with five phytochemicals, while genistein was maximally synergistic with EGCG. In contrast, DU145 cells showed resveratrol-mediated maximum synergy with equol, EGCG and genistein, with I3C mediating maximum synergy with only quercetin and curcumin. Knockdown of pTEN expression in DU145 cells abrogated the synergistic effect of resveratrol without affecting the synergy profile of I3C and quercetin. Discussion: Our study identifies patterns of synergy that are dependent on tumour cell genotype and are independent of androgen signaling but are dependent on pTEN. Despite evident cell-type specificity in both maximally-synergistic combinations and the pathways that phytochemicals modulate, these combinations interact with similar prostate cancer protein targets. Here, we identify an approach that, when coupled with advanced data analysis methods, may suggest optimal dietary phytochemical combinations for individual consumption based on tumour molecular profile

The BRCA-1 binding protein BRAP2 is a novel, negative regulator of nuclear import of viral proteins, dependent on phosphorylation flanking the nuclear localization signal

This study describes for the first time the ability of the novel BRCA1-binding protein 2 (BRAP2) to inhibit the nuclear import of specific viral proteins dependent on phosphorylation. Ectopic expression of BRAP2 in transfected African green monkey kidney COS-7 cells was found to significantly reduce nuclear localization signal (NLS)-dependent nuclear accumulation of either simian virus SV40 large-tumor antigen (T-ag) or human cytomegalovirus DNA polymerase processivity factor ppUL44; this was also observed in HL-60 human promyelocytic leukemia cells on induction of BRAP2 expression by vitamin D3 treatment. BRAP2 inhibition of nuclear accumulation was dependent on phosphorylation sites flanking the respective NLSs, where substitution of the cyclin-dependent kinase site T124 of T-ag with Ala or Asp prevented or enhanced BRAP2 inhibition of nuclear import, respectively. Substitution of T427 within the NLS of ppUL44 gave similar results, whereas no effect of BRAP2 was observed on nuclear targeting of other viral proteins, such as herpes simplex virus-1 pUL30, which lacks a phosphorylation site near its NLS, and the human immunodeficiency virus-1 Tat protein. Pulldowns/AlphaScreen assays indicated direct, high-affinity binding of BRAP2(442–592) to T-ag(111–135), strictly dependent on negative charge at T124 and the NLS. All results are consistent with BRAP2 being a novel, phosphorylation-regulated negative regulator of nuclear import, with potential as an antiviral agent

swoil n; 'seal oil'

seal nHe told me to give her / A cup of old swoil.PRINTED ITEM JUL 1 1988G.M.Story WKUsed I and SupUsed I3Used Isile,soil,swale,swile,swoil(e),bay,harbour,harp,hood,old,square flipper,square a,young,bedlamer,dotard,ragged-jacket,saddleback,turner,white-coat,pelt n,sculp n;~bait/bat/cat/catcher/dart/fat/finger/hunt(er)/gun/hand/heaMore collocations:~hunting/shot/skin(er)/soap/twine/vat/bird/penis/worm/frame/oil/pan/pass/patch;~fish/er(y)/ing;dog1;pup;cock,cod worm;snub1;blow hole;bobbing~;sealer1;fish kille

Computational Insights into the Inhibitory Mechanism of Human AKT1 by an Orally Active Inhibitor, MK-2206

<div><p>The AKT signaling pathway has been identified as an important target for cancer therapy. Among small-molecule inhibitors of AKT that have shown tremendous potential in inhibiting cancer, MK-2206 is a highly potent, selective and orally active allosteric inhibitor. Promising preclinical anticancer results have led to entry of MK-2206 into Phase I/II clinical trials. Despite such importance, the exact binding mechanism and the molecular interactions of MK-2206 with human AKT are not available. The current study investigated the exact binding mode and the molecular interactions of MK-2206 with human AKT isoforms using molecular docking and (un)binding simulation analyses. The study also involved the docking analyses of the structural analogs of MK-2206 to AKT1 and proposed one as better inhibitor. The Dock was used for docking simulations of MK-2206 into the allosteric site of AKT isoforms. The Ligplot+ was used for analyses of polar and hydrophobic interactions between AKT isoforms and the ligands. The MoMa-LigPath web server was used to simulate the ligand (un)binding from the binding site to the surface of the protein. In the docking and (un)binding simulation analyses of MK-2206 with human AKT1, the Trp-80 was the key residue and showed highest decrease in the solvent accessibility, highest number of hydrophobic interactions, and the most consistent involvement in all (un)binding simulation phases. The number of molecular interactions identified and calculated binding energies and dissociation constants from the co-complex structures of these isoforms, clearly explained the varying affinity of MK-2206 towards these isoforms. The (un)binding simulation analyses identified various additional residues which despite being away from the binding site, play important role in initial binding of the ligand. Thus, the docking and (un)binding simulation analyses of MK-2206 with AKT isoforms and its structure analogs will provide a suitable model for studying drug-protein interaction and will help in designing better drugs.</p></div

Procheck analyses for quality of structure models of AKT2 and AKT3 with the common template.

<p>Ramachandran plot analyses showing the percentage of residues lying in each of the four different regions. In disallowed region, the number of residues is also given in parantheses with percentage. The number of labeled residues in all Ramachandrans and Chi1–Chi2 are also given in the table.</p><p>Procheck analyses for quality of structure models of AKT2 and AKT3 with the common template.</p

The nuclear transporter importin 13 is critical for cell survival during embryonic stem cell differentiation

Nuclear transporter Importin (Imp, Ipo) 13 is known to transport various mammalian cargoes into/out of the nucleus, but its role in directing cell-fate is unclear. Here we examine the role of Imp13 in the maintenance of pluripotency and differentiation of embryonic stem cells (ESCs) for the first time, using an embryonic body (EB)-based model. When induced to differentiate, Ipo13−/− ESCs displayed slow proliferation, reduced EB size, and lower expression of the proliferation marker KI67, concomitant with an increase in the number of TUNEL+ nuclei compared to wildtype ESCs. At days 5 and 10 of differentiation, Ipo13−/− EBs also showed enhanced loss of the pluripotency transcript OCT3/4, and barely detectable clusters of OCT3/4 positive cells. Day 5 Ipo13−/− EBs further exhibited reduced levels of the mesodermal markers Brachyury and Mixl1, correlating with reduced numbers of haemoglobinised cells generated. Our findings suggest that Imp13 is critical to ESC survival as well as early post-gastrulation differentiation

(Un)binding simulation analyses of MK-2206 binding to the allosteric site of human AKT1.

<p>Panels A–I: The (un)binding simulation phases of MK-2206; ‘A’ denotes farthest phase from the binding site, ‘H’ - the closest to the binding site, and ‘I’ - the binding site phase. The hydrogen bonds are shown as green-dashed lines with indicated bond length and the residues involved in hydrophobic interactions are shown as red arcs. The residues which are common to the last phase (F) are encircled.</p

The binding strength of MK-2206 to the three AKT isoforms given by various scores are listed in the table.

<p>The binding strength of MK-2206 to the three AKT isoforms given by various scores are listed in the table.</p

Comparison of MK-2206 binding and interacting residues of all three isoforms of AKT.

<p>Only one residue Asn-53 was shared among interacting residues of AKT1 and AKT2, and shown as encircled in green. Three position-equivalent-residues (residues of different isoforms falling at same column position in the isoform alignment) were shared among interacting residues of AKT2 and AKT3, and shown as encircled in red.</p