Down-regulation of Survivin enhances sensitivity to BPR0L075 in human cancer cells via caspase-independent mechanisms

Background: BPR0L075 [6-methoxy-3-(3',4',5'-trimethoxy-benzoyl)-1H-indole] is a novel anti-cancer compound. It inhibits tubulin polymerization and induces mitochondrial-dependent apoptosis in various human cancer cells with different multi-drug resistance (MDR) status. Over-expression of an anti-apoptotic molecule, survivin, causes drug-resistance in various cancers. Survivin inhibits apoptosis by interfering caspase-3 and promotes cell growth by stabilizing microtubule networks. Here, we determined the effects of down-regulation of survivin in BPR0L075 (L075) treatment. Methods: Western blot analysis was used to determine the expression level of survivin in L075-untreated/-treated human oral carcinoma KB and nasopharyngeal carcinoma HONE-1 cancer cells. siRNA was used to down-regulate endogenous survivin. MTT cell viability assay, real-time caspase-3 activity assay and immuno-fluorescence microscopy were used to analyze downstream effects. Results: Survivin expression was up-regulated in both KB and HONE-1 cells in response to L075 treatment. Down-regulation of survivin induced hyper-sensitivity to L075 in KB and re-stored sensitivity to L075 in KB-derived L075-resistant KB-L30 cancer cells. At the molecular level, down-regulation of survivin induced changes in microtubule dynamics in both KB and KB-L30 cells. Surprisingly, down-regulation of survivin did not enhance the activity of caspase-3 in L075 therapy. Instead, down-regulation of survivin induced translocation of the apoptosis-inducing factor (AIF) from cytoplasm to nucleus. Conclusion: Down-regulation of survivin improved drug sensitivity to L075 in both KB and L075-resistant KB-L30 cancer cells, possibly through a tubulin-dependent and caspase-independent mechanism. We suggest that combining BPR0L075 and survivin inhibitor may give better clinical outcome than the use of BPR0L075 monotherapy in future clinical trials

Retraction and Generalized Extension of Computing with Words

Fuzzy automata, whose input alphabet is a set of numbers or symbols, are a formal model of computing with values. Motivated by Zadeh's paradigm of computing with words rather than numbers, Ying proposed a kind of fuzzy automata, whose input alphabet consists of all fuzzy subsets of a set of symbols, as a formal model of computing with all words. In this paper, we introduce a somewhat general formal model of computing with (some special) words. The new features of the model are that the input alphabet only comprises some (not necessarily all) fuzzy subsets of a set of symbols and the fuzzy transition function can be specified arbitrarily. By employing the methodology of fuzzy control, we establish a retraction principle from computing with words to computing with values for handling crisp inputs and a generalized extension principle from computing with words to computing with all words for handling fuzzy inputs. These principles show that computing with values and computing with all words can be respectively implemented by computing with words. Some algebraic properties of retractions and generalized extensions are addressed as well.Comment: 13 double column pages; 3 figures; to be published in the IEEE Transactions on Fuzzy System

(Dithio­benzoato-κ2 S,S′)[hydridotris(pyrazol-1-yl-κN 2)borato](triphenyl­phosphine-κP)ruthenium(II)

Reaction of [Ru(Tp)Cl(PPh3)2] (Tp = hydridotrispyrazolyl­borate) with ammonium dithio­benzoate in methanol leads to the formation of the title compound, [Ru(C9H10BN6)(C7H5S2)(C18H15P)]. In the crystal structure, the Ru atom is coordinated by three N atoms of the Tp ligand, one P atom of the triphenyl­phosphine ligand and the two S atoms of the dithio­benzoate ligand within a slightly distorted octa­hedron. The Ru—S bonds are slightly different [2.321 (1) and 2.396 (1) Å] and the average N—Ru—N angle is 86.31°

(Benzonitrile-κN)chlorido[hydrido­tris(pyrazol-1-yl-κN 2)borato](triphenyl­phosphine-κP)ruthenium(II) ethanol solvate. Corrigendum

Corrigendum to Acta Cryst. (2009), E65, m438

Macrophage activation increases the invasive properties of hepatoma cells by destabilization of the adherens junction

AbstractTumor-associated macrophages play an important role in tumor progression, but whether they exert a tumor-progressive effect remains controversial. Here, we demonstrated that activated macrophage-conditioned medium (AMCM) obtained from RAW macrophages (RAW/AMCM) induced epithelial-mesenchymal transition (EMT) and stimulated the migratory and invasive activities of HepG2 cells, whereas control conditioned media had no effect. Epithelial-cadherin (E-cadherin) and β-catenin staining patterns were altered at the adherens junctions by RAW/AMCM treatment, with an approximately 50% decrease in E-cadherin and β-catenin in the cell membrane. Importantly, levels of β-catenin-associated E-cadherin were also decreased. Following RAW/AMCM treatment, enhanced activation of c-Src was seen prior to increased tyrosine phosphorylation of β-catenin, and this led to the destabilization of adherens junctions. Pretreatment of HepG2 cells with the Src kinase inhibitor, PP2, completely abolished the effects of RAW/AMCM on the EMT, migration, invasion, and expression and association of E-cadherin and β-catenin. AMCMs obtained from human THP-1 monocytes and mouse peritoneal macrophages also caused disassembly of the adherens junctions and migration of HepG2 cells. Furthermore, inhibition of the epidermal growth factor receptor (EGFR) with gefitinib partially prevented the downregulation of E-cadherin and β-catenin at the adherens junctions and migration behavior induced by RAW/AMCM. Our results suggest that activated macrophages have a tumor-progressive effect on HepG2 cells which involves the c-Src- and EGFR-dependent signaling cascades

Severe 2009 H1N1 infection in early pregnancy

AbstractObjectiveBecause pregnancy suppresses the immune system, women at any stage of pregnancy are more susceptible to bacterial and viral infection. Pregnant women might thus be at increased risk of complications from pandemic H1N1 virus infection, and illness may progress rapidly.Case ReportA 23-year-old primigravida at 9 weeks’ gestation was presented to our institution because of the sudden onset of sore throat, fever, chills, and vomiting for 5 days. She was diagnosed with early pregnancy H1N1 infection, vulvar herpes infection, and impending intravascular disseminated coagulopathy. Oseltamivir (Tamiflu) 75 mg and valacyclovir 500 mg were then administered orally twice daily for 5 days. The patient’s fever, chills, and vomiting subsided 2 days later. The real-time reverse-transcriptase polymerase chain reaction (RT-PCR) analysis of nasal discharge for influenza virus types A and B showed positive results for the A/H1N1 influenza virus. The early pregnancy was terminated by therapeutic curettage at the patient’s request. The surgical specimen revealed products of conception with the presence of necrotic chorionic villi, and focal lymphocytes in decidual tissue. RT-PCR analysis of gestational tissue for A/H1N1 was negative.ConclusionPregnant women with H1N1 infection seem to benefit from antiviral therapy

Metabolic Stress-Induced Phosphorylation of KAP1 Ser473 Blocks Mitochondrial Fusion in Breast Cancer Cells

Mitochondrial dynamics during nutrient starvation of cancer cells likely exert profound effects on their capability for metastatic progression. Here, we report that KAP1 (TRIM28), a transcriptional coadaptor protein implicated in metastatic progression in breast cancer, is a pivotal regulator of mitochondrial fusion in glucose-starved cancer cells. Diverse metabolic stresses induced Ser473 phosphorylation of KAP1 (pS473-KAP1) in a ROS- and p38-dependent manner. Results from live-cell imaging and molecular studies revealed that during the first 6 to 8 hours of glucose starvation, mitochondria initially underwent extensive fusion, but then subsequently fragmented in a pS473-KAP1-dependent manner. Mechanistic investigations using phosphorylation-defective mutants revealed that KAP1 Ser473 phosphorylation limited mitochondrial hyperfusion in glucose-starved breast cancer cells, as driven by downregulation of the mitofusin protein MFN2, leading to reduced oxidative phosphorylation and ROS production. In clinical specimens of breast cancer, reduced expression of MFN2 corresponded to poor prognosis in patients. In a mouse xenograft model of human breast cancer, there was an association in the core region of tumors between MFN2 downregulation and the presence of highly fragmented mitochondria. Collectively, our results suggest that KAP1 Ser473 phosphorylation acts through MFN2 reduction to restrict mitochondrial hyperfusion, thereby contributing to cancer cell survival under conditions of sustained metabolic stress

Methyl­ene bis­(dithio­benzoate)

In the title compound, C15H12S4, two phenyl­dithio­carboxyl­ate units are linked through a methyl­ene C atom on a twofold rotation axis. The central S—CH2—S angle of 116.9 (5)° is significantly larger than the ideal tetra­hedral value. The dihedral angle formed by the two phenyl rings is 68.2 (1)°. The refined Flack parameter of 0.2 (3) does not permit unambiguous determination of the absolute structure

Survivin counteracts the therapeutic effect of microtubule de-stabilizers by stabilizing tubulin polymers

<p>Abstract</p> <p>Background</p> <p>Survivin is a dual function protein. It inhibits the apoptosis of cells by inhibiting caspases, and also promotes cell growth by stabilizing microtubules during mitosis. Over-expression of survivin has been demonstrated to induce drug-resistance to various chemo-therapeutic agents such as cisplatin (DNA damaging agent) and paclitaxel (microtubule stabilizer) in cancers. However, survivin-induced resistance to microtubule de-stabilizers such as <it>Vinca </it>alkaloids and Combretastatin A-4 (CA-4)-related compounds were seldom demonstrated in the past. Furthermore, the question remains as to whether survivin plays a dominant role in processing cytokinesis or inhibiting caspases activity in cells treated with anti-mitotic compounds. The purpose of this study is to evaluate the effect of survivin on the resistance and susceptibility of human cancer cells to microtubule de-stabilizer-induced cell death.</p> <p>Results</p> <p>BPR0L075 is a CA-4 analog that induces microtubule de-polymerization and subsequent caspase-dependent apoptosis. To study the relationship between the expression of survivin and the resistance to microtubule de-stabilizers, a KB-derived BPR0L075-resistant cancer cell line, KB-<it>L30</it>, was generated for this study. Here, we found that survivin was over-expressed in the KB-<it>L30 </it>cells. Down-regulation of survivin by siRNA induced hyper-sensitivity to BPR0L075 in KB cells and partially re-stored sensitivity to BPR0L075 in KB-<it>L30 </it>cells. Western blot analysis revealed that down-regulation of survivin induced microtubule de-stabilization in both KB and KB-<it>L30 </it>cells. However, the same treatment did not enhance the down-stream caspase-3/-7 activities in BPR0L075-treated KB cells. Translocation of a caspase-independent apoptosis-related molecule, apoptosis-inducing factor (AIF), from cytoplasm to the nucleus was observed in survivin-targeted KB cells under BPR0L075 treatment.</p> <p>Conclusion</p> <p>In this study, survivin plays an important role in the stability of microtubules, but not with caspases inhibition. Over-expression of survivin counteracts the therapeutic effect of microtubule de-stabilizer BPR0L075 probably by stabilizing tubulin polymers, instead of the inhibition of caspase activity in cancer cells. Besides microtubule-related caspase-dependent cell death, caspase-independent mitotic cell death could be initiated in survivin/BPR0L075 combination treatments. We suggest that combining microtubule de-stabilizers with a survivin inhibitor may attribute to a better clinical outcome than the use of anti-mitotic monotherapy in clinical situations.</p