Search

Objective: To investigate the antioxidant and cytotoxic properties of the most active extracts from Ulva lactuca and Laurencia obtusa against colon and cervical cancer cell lines. Methods: The antioxidant radical scavenging activity of the algal extracts was estimated using the 2,2-diphenyl-1-picrylhydrazyl colorimetric assay. Moreover, the cytotoxic potential of these bioactive extracts was studied against HCT-116 and HeLa cells by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay. Wound healing analysis was adopted to evaluate the anti-metastatic effects of protein extracts from both algae. Cell cycle analysis was performed by flow cytometry, and apoptotic bodies were detected using 4’,6-diamidino-2-phenylindole fluorescent staining. Amino acids of hydrolyzed protein extract were separated and identified chromatographically by high performance liquid chromatography. Results: The green algae Ulva lactuca had higher lipid content than Laurencia obtusa, whereas the latter had higher protein content with high antioxidant capacity. Protein extracts had significant dose- and time-dependent cytotoxicity and anti-metastatic activity against HCT-116 cells. Protein b extracts of both algae obtained from the chloroform:hexane solvent lipid-free residue caused morphological changes and induced apoptosis of HCT-116 cells. Further analysis revealed that apoptosis induced upon Laurencia obtusa protein b treatment was triggered via the ROS pathway, causing a significant increase in the sub-G1 population. Glycine and arginine (5.94 and 5.47 μM, respectively) were the most common amino acids in Laurencia obtusa protein b extract. Conclusions: Proteins of Laurencia obtusa and Ulva lactuca could be considered as an adjuvant nutraceutical source of pro-apoptotic and anti-metastatic biomolecules against colon cancer.

PURPOSE To assess the knowledge and intention for colorectal cancer (CRC) screening within the Lebanese community before and after a guided tour through an inflatable colon model. METHODS The Cancer Prevention and Control Program, Naef K. Basile Cancer Institute at the American University of Beirut Medical Center in collaboration with AMALOUNA educational nongovernmental organization launched awareness campaigns during which a walk-through inflatable colon was displayed. Pre- and post-surveys related to the age of screening, risk factors, symptoms, and CRC prevention were collected anonymously before and after touring the inflatable colon to assess the effectiveness of this educational tool. RESULTS Compiled data collected from 782 participants revealed that older age and higher education were predictors of favorable CRC screening knowledge and behaviors before entering the inflatable colon. Interestingly, touring the inflatable colon model significantly improved participants’ awareness and knowledge about CRC. Most importantly, it increased their willingness for screening and social engagement and comfort discussing and promoting CRC screening. CONCLUSION Overall, these results indicate that the interactive colon is an effective educational tool that can make a positive impact by improving the community CRC awareness and interest in CRC screening. They also highlight the importance of such educational efforts conducted in the community to create more awareness about CRC and emphasize the importance of its prevention.

Background: Adult T-cell leukemia/lymphoma (ATL) is an aggressive malignancy secondary to chronic human T-cell lymphotropic virus 1 infection, triggered by the virally encoded oncoprotein Tax. The transforming activity and subcellular localization of Tax is strongly influenced by posttranslational modifications, among which ubiquitylation and SUMOylation have been identified as key regulators of the nuclear/cytoplasmic shuttling of Tax, as well as its ability to activate NF-κB signaling. Results: Adding to the complex posttranslational modification landscape of Tax, we here demonstrate that Tax also interacts with the ubiquitin-related modifier 1 (Urm1). Conjugation of Urm1 to Tax results in a redistribution of Tax to the cytoplasm and major increase in the transcription of the NF-ĸB targets Rantes and interleukin-6. Utilizing a tax-transgenic Drosophila model, we show that the Urm1-dependent subcellular targeting of Tax is evolutionary conserved, and that the presence of Urm1 is strongly correlated with the transcriptional output of Diptericin, an antimicrobial peptide and established downstream target of NF-κB in flies. Conclusions: These data put forward Urm1 as a novel Tax modifier that modulates its oncogenic activity and hence represents a potential novel target for developing new strategies for treating ATL. Originally included in thesis in manuscript form.

Nucleophosmin-1 (NPM1) is the most frequently mutated gene in acute myeloid leukemia (AML). Addition of retinoic acid (RA) to chemotherapy was proposed to improve survival of some of these patients. Here, we found that RA or arsenic trioxide synergistically induce proteasomal degradation of mutant NPM1 in AML cell lines or primary samples, leading to differentiation and apoptosis. NPM1 mutation not only delocalizes NPM1 from the nucleolus, but it also disorganizes promyelocytic leukemia (PML) nuclear bodies. Combined RA/arsenic treatment significantly reduced bone marrow blasts in 3 patients and restored the subnuclear localization of both NPM1 and PML. These findings could explain the proposed benefit of adding RA to chemotherapy in NPM1 mutant AMLs, and warrant a broader clinical evaluation of regimen comprising a RA/arsenic combination.

A phenylethanoid, two steroids, a flavone glucoside and a chalcone have been isolated for the first time from the stems of Calicotome villosa together with a previously isolated flavone glucoside. Their structures were determined by spectroscopic analyses (NMR, HRMS) as basalethanoïd B (1), β-sitosterol and stigmasterol (2), chrysine-7-O-β-d-glucopyranoside (3), chrysine 7-((6′′-O-acetyl)-O-β-d-glucopyranoside) (4) and calythropsin (5). The crude extracts and the isolated compounds (except 4), were evaluated for their antioxidant, antimicrobial (against two Gram-positive bacterial strains: Staphylococcus aureus, Bacillus cereus, four Gram-negative bacterial strains: Staphylococcus epidermidis, Klebsiella pneumonia, Acinetobacter baumanii, and three yeasts: Candida albicans, Candida tropicalis, and Candida glabrata), hemolytic, antidiabetic, anti-inflammatory and cytotoxic activity. The crude extracts showed good ability to scavenge the free radical DPPH. Methanol stem extract followed by the dichloromethane stem extract showed moderate antimicrobial potency; furthermore, at 1 mg/mL the methanol extract showed an inhibition of C. albicans growth comparable to nystatin. Dichloromethane, methanol, and aqueous extracts inhibited 98%, 90%, and 80% of HeLa cell proliferation at 2 mg/mL respectively. Weak hypoglycemic and hemolytic effects were exhibited by the crude extracts. Among all the tested compounds, compound 3 showed remarkable hypoglycemic potential (93% at 0.1 mg/mL) followed by compound 5 (90% at 0.3 mg/mL). Compound 5 was the most effective in the DPPH. scavenging assay (100% at 0.1 mg/mL) and cytotoxic assay on HeLa cells (99% and 90% after 24 and 48 h of treatment at 0.1 mg/mL, respectively). No anti-inflammatory effects were displayed by any of the crude extracts or the isolated compounds at any of the tested concentrations.

The HTLV-1 Tax transactivator initiates transformation in adult T-cell leukemia/lymphoma (ATL), a highly aggressive chemotherapy-resistant malignancy. The arsenic/interferon combination, which triggers degradation of the Tax oncoprotein, selectively induces apoptosis of ATL cell lines and has significant clinical activity in Tax-driven murine ATL or patients. Yet, the role of Tax expression in maintaining the transformed phenotype and of Tax loss in ATL response is disputed and the molecular mechanisms driving degradation remain elusive. Here we demonstrate that ATL-derived or HTLV-1 transformed cells are addicted to continuous Tax expression, suggesting that Tax degradation underlies clinical responses to the arsenic/interferon combination. The latter enforces PML nuclear body (NB) formation and partner protein recruitment. In arsenic/interferon-treated ATL-derived cells, Tax is recruited onto NBs, undergoes PML-dependent hyper-sumoylation by SUMO2/3, but not SUMO1, ubiquitination by RNF4 and proteasome-dependent degradation. Thus, the arsenic/interferon combination clears ATL through degradation of its Tax driver and could have broader therapeutic value by promoting degradation of other pathogenic sumoylated proteins.

The human T-cell lymphotropic virus type I (HTLV-1) Tax transactivator initiates transformation in adult T-cell leukemia/lymphoma (ATL), a highly aggressive chemotherapy-resistant malignancy. The arsenic/interferon combination, which triggers degradation of the Tax oncoprotein, selectively induces apoptosis of ATL cell lines and has significant clinical activity in Tax-driven murine ATL or human patients. However, the role of Tax loss in ATL response is disputed, and the molecular mechanisms driving degradation remain elusive. Here we demonstrate that ATL-derived or HTLV-1-transformed cells are dependent on continuous Tax expression, suggesting that Tax degradation underlies clinical responses to the arsenic/interferon combination. The latter enforces promyelocytic leukemia protein (PML) nuclear body (NB) formation and partner protein recruitment. In arsenic/interferon-treated HTLV-1 transformed or ATL cells, Tax is recruited onto NBs and undergoes PML-dependent hyper-sumoylation by small ubiquitin-like modifier (SUMO)2/3 but not SUMO1, ubiquitination by RNF4, and proteasome-dependent degradation. Thus, the arsenic/interferon combination clears ATL through degradation of its Tax driver, and this regimen could have broader therapeutic value by promoting degradation of other pathogenic sumoylated proteins.

HTLV-I associated adult T-cell leukemia/lymphoma (ATL) carries a dismal prognosis due to chemo-resistance and immuno-compromised micro-environment. The combination of zidovudine and interferon-alpha (IFN) significantly improved survival in ATL. Promising results were reported by adding arsenic trioxide to zidovudine and IFN. Here we assessed Th1/Th2/Treg cytokine gene expression profiles in 16 ATL patients before and 30 days after treatment with arsenic/IFN/zidovudine, in comparison with HTLV-I healthy carriers and sero-negative blood donors. ATL patients at diagnosis displayed a Treg/Th2 cytokine profile with significantly elevated transcript levels of Foxp3, interleukin-10 (IL-10), and IL-4 and had a reduced Th1 profile evidenced by decreased transcript levels of interferon-γ (IFN-γ) and IL-2. Most patients (15/16) responded, with CD4+CD25+ cells significantly decreasing after therapy, paralleled by decreases in Foxp3 transcript. Importantly, arsenic/IFN/zidovudine therapy sharply diminished IL-10 transcript and serum levels concomittant with decrease in IL-4 and increases in IFN-γ and IL-2 mRNA, whether or not values were adjusted to the percentage of CD4+CD25+ cells. The observed shift from a Treg/Th2 phenotype before treatment toward a Th1 phenotype after treatment with arsenic/IFN/zidovudine may play an important role in restoring an immuno-competent micro-environment, which enhances the eradication of ATL cells and the prevention of opportunistic infections.

Background HTLV-I associated adult T-cell leukemia/lymphoma (ATL) carries a dismal prognosis due to chemo-resistance and immuno-compromised micro-environment. The combination of zidovudine and interferon-alpha (IFN) significantly improved survival in ATL. Promising results were reported by adding arsenic trioxide to zidovudine and IFN. Results Here we assessed Th1/Th2/Treg cytokine gene expression profiles in 16 ATL patients before and 30 days after treatment with arsenic/IFN/zidovudine, in comparison with HTLV-I healthy carriers and sero-negative blood donors. ATL patients at diagnosis displayed a Treg/Th2 cytokine profile with significantly elevated transcript levels of Foxp3, interleukin-10 (IL-10), and IL-4 and had a reduced Th1 profile evidenced by decreased transcript levels of interferon-γ (IFN-γ) and IL-2. Most patients (15/16) responded, with CD4+CD25+ cells significantly decreasing after therapy, paralleled by decreases in Foxp3 transcript. Importantly, arsenic/IFN/zidovudine therapy sharply diminished IL-10 transcript and serum levels concomittant with decrease in IL-4 and increases in IFN-γ and IL-2 mRNA, whether or not values were adjusted to the percentage of CD4+CD25+ cells. Finally, IL-10 transcript level negatively correlated with clinical response at Day 30. Conclusions The observed shift from a Treg/Th2 phenotype before treatment toward a Th1 phenotype after treatment with arsenic/IFN/zidovudine may play an important role in restoring an immuno-competent micro-environment, which enhances the eradication of ATL cells and the prevention of opportunistic infections.

Although human T-cell leukemia virus type 1 and 2 (HTLV-1 and HTLV-2) share similar genetic organization, they have major differences in their pathogenesis and disease manifestation. HTLV-1 is capable of transforming T lymphocytes in infected patients and subsequently leads to adult T cell leukemia/lymphoma (ATL) whereas HTLV-2 is not clearly associated with lymphoproliferative diseases. Numerous studies have provided accumulating evidence on the involvement of the viral transactivators Tax-1 versus Tax-2 in T cell transformation. Tax-1 is a potent transcriptional activator of both viral and cellular genes. Tax-1 posttranslational modifications and specifically ubiquitylation and SUMOylation have been implicated in NF-кB activation and may contribute to its transformation capacity. Although Tax-2 has similar protein structure compared to Tax-1, the two proteins display differences both in their protein-protein interaction and activation of signal transduction pathways. Recent studies on Tax-2 have suggested ubiquitylation and SUMOylation independent mechanisms of NF-кB activation. In this present review, structural and functional differences between Tax-1 and Tax- 2 will be summarized. Specifically, we will address their subcellular localization, nuclear trafficking and their effect on cellular regulatory proteins. A special attention will be given to Tax-1/Tax-2 post-translational modification such as ubiquitylation, SUMOylation, phosphorylation, acetylation, NF-кB activation and protein-protein interactions involved in oncogenecity both in vivo and in vitro.

Retroviruses are associated with a wide variety of diseases, including immunological, neurological disorders, and different forms of cancer. Among retroviruses, Oncovirinae regroup according to their genetic structure and sequence, several related viruses such as human T-cell lymphotropic viruses types 1 and 2 (HTLV-1 and HTLV-2), simian T cell lymphotropic viruses types 1 and 2 (STLV-1 and STLV-2), and bovine leukemia virus (BLV). As in many diseases, animal models provide a useful tool for the studies of pathogenesis, treatment, and prevention. In the current review, an overview on different animal models used in the study of these viruses will be provided. A specific attention will be given to the HTLV-1 virus which is the causative agent of adult T-cell leukemia/lymphoma (ATL) but also of a number of inflammatory diseases regrouping the HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), infective dermatitis and some lung inflammatory diseases. Among these models, rabbits, monkeys but also rats provide an excellent in vivo tool for early HTLV-1 viral infection and transmission as well as the induced host immune response against the virus. But ideally, mice remain the most efficient method of studying human afflictions. Genetically altered mice including both transgenic and knockout mice, offer important models to test the role of specific viral and host genes in the development of HTLV-1-associated leukemia. The development of different strains of immunodeficient mice strains (SCID, NOD, and NOG SCID mice) provide a useful and rapid tool of humanized and xenografted mice models, to test new drugs and targeted therapy against HTLV-1-associated leukemia, to identify leukemia stem cells candidates but also to study the innate immunity mediated by the virus. All together, these animal models have revolutionized the biology of retroviruses, their manipulation of host genes and more importantly the potential ways to either prevent their infection or to treat their associated diseases.

Bex F, 1999, J VIROL, V73, P738; Bex F, 1998, MOL CELL BIOL, V18, P2392; Bex F, 1998, METHODS, V16, P83, DOI 10.1006-meth.1998.0646; Burton M, 2000, J VIROL, V74, P2351, DOI 10.1128-JVI.74.5.2351-2364.2000; Chiari E, 2004, J VIROL, V78, P11823, DOI 10.1128-JVI.78.21.11823-11832.2004; Chu ZL, 1999, J BIOL CHEM, V274, P15297, DOI 10.1074-jbc.274.22.15297; Chubb JR, 2003, CELL, V112, P403, DOI 10.1016-S0092-8674(03)00078-3; Duprez E, 1999, J CELL SCI, V112, P381; Durkin SS, 2006, J BIOL CHEM, V281, P31705, DOI 10.1074-jbc.M607011200; Gurskaya NG, 2006, NAT BIOTECHNOL, V24, P461, DOI 10.1038-nbt1191; Huang TT, 2003, CELL, V115, P565, DOI 10.1016-S0092-8674(03)00895-X; Iha H, 2003, ONCOGENE, V22, P8912, DOI 10.1038-sj.onc.1207058; Johnson ES, 1997, J BIOL CHEM, V272, P26799, DOI 10.1074-jbc.272.43.26799; Journo C, 2009, PLOS PATHOG, V5, DOI 10.1371-journal.ppat.1000521; Kfoury Y, 2008, ONCOGENE, V27, P1665, DOI 10.1038-sj.onc.1210804; Lamsoul I, 2005, MOL CELL BIOL, V25, P10391, DOI 10.1128-MCB.25.23.10391-10406.2005; Lodewick J, 2009, VIROLOGY, V386, P68, DOI 10.1016-j.virol.2008.12.043; Mabb AM, 2006, NAT CELL BIOL, V8, P986, DOI 10.1038-ncb1458; Matsuoka M, 2007, NAT REV CANCER, V7, P270, DOI 10.1038-nrc2111; Meertens L, 2004, J BIOL CHEM, V279, P43307, DOI 10.1074-jbc.M400497200; Nasr R, 2006, BLOOD, V107, P4021, DOI 10.1182-blood-2005-09-3572; Navascues J, 2007, CHROMOSOMA, V116, P441, DOI 10.1007-s00412-007-0107-7; Nejmeddine M, 2005, J BIOL CHEM, V280, P29653, DOI 10.1074-jbc.M502639200; Nejmeddine M, 2009, BLOOD, V114, P1016, DOI 10.1182-blood-2008-03-136770; SEUFERT W, 1995, NATURE, V373, P78, DOI 10.1038-373078a0; Strouboulis J, 1996, J CELL SCI, V109, P1991; Sun SC, 2000, AIDS RES HUM RETROV, V16, P1591, DOI 10.1089-08892220050193001; Tang ED, 2003, J BIOL CHEM, V278, P37297, DOI 10.1074-jbc.M303389200; WUERZBERGERDAVI.SM, 2007, DNADAMAGE ONCOGENE, V26, P641; Xiao GT, 2001, EMBO J, V20, P6805, DOI 10.1093-emboj-20.23.6805; Yamaoka S, 1998, CELL, V93, P1231, DOI 10.1016-S0092-8674(00)81466-X; Yan PR, 2009, BLOOD, V113, P4370, DOI 10.1182-blood-2008-10-185660; Zhou HL, 2004, NATURE, V427, P167, DOI 10.1038-nature02273

Background HTLV-I associated adult T-cell leukemia/lymphoma (ATL) carries a dismal prognosis due to chemo-resistance and immuno-compromised micro-environment. The combination of zidovudine and interferon-alpha (IFN) significantly improved survival in ATL. Promising results were reported by adding arsenic trioxide to zidovudine and IFN. Methods Here we assessed Th1/Th2/Treg cytokine gene expression profiles in 16 ATL patients before and 30 days after treatment with arsenic/IFN/zidovudine, in comparison with HTLV-I healthy carriers and sero-negative blood donors. Results ATL patients at diagnosis displayed a Treg/Th2 cytokine profile with significantly elevated transcript levels of Foxp3, interleukin-10 (IL-10), and IL-4 and had a reduced Th1 profile evidenced by decreased transcript levels of interferon-γ (IFN-γ) and IL-2. Most patients (15/16) responded, with CD4+CD25+ cells significantly decreasing after therapy, paralleled by decreases in Foxp3 transcript. Importantly, arsenic/IFN/zidovudine therapy sharply diminished IL-10 transcript and serum levels concomittant with decrease in IL-4 and increases in IFN-γ and IL-2 mRNA, whether or not values were adjusted to the percentage of CD4+CD25+ cells. Conclusions The observed shift from a Treg/Th2 phenotype before treatment toward a Th1 phenotype after treatment with arsenic/IFN/zidovudine may play an important role in restoring an immuno-competent micro-environment, which enhances the eradication of ATL cells and the prevention of opportunistic infections. Disclosures: Off Label Use: Off label use of arsenic trioxide, zidovudine and interferon-alpha for the treatment of adult T cell leukemia/lymphoma.