Inhibition of GATA2 restrains cell proliferation and enhances apoptosis and chemotherapy mediated apoptosis in human GATA2 overexpressing AML cells

GATA2, a zinc finger transcription factor predominantly expressed in hematopoietic cells, acts as an essential regulator of hematopoietic stem cell generation, survival and functionality. Loss and gain of GATA2 expression has been implicated in myelodysplastic syndrome and acute myeloid leukemia (AML) yet the precise biological impact of GATA2 expression on human AML cell fate decisions remains ambiguous. Herein, we performed large-scale bioinformatics that demonstrated relatively frequent GATA2 overexpression in AML patients as well as select human AML (or AML-like) cell lines. By using shRNAi to target GATA2 in these AML cell lines, and an AML cell line expressing normal levels of GATA2, we found that inhibition of GATA2 caused attenuated cell proliferation and enhanced apoptosis exclusively in AML cell lines that overexpress GATA2. We proceeded to pharmacologically inhibit GATA2 in concert with AML chemotherapeutics and found this augmented cell killing in AML cell lines that overexpress GATA2, but not in an AML cell line expressing normal levels of GATA2. These data indicate that inhibition of GATA2 enhances chemotherapy-mediated apoptosis in human AML cells overexpressing GATA2. Thus, we define novel insights into the oncogenic role of GATA2 in human AML cells and suggest the potential utilization of transient GATA2 therapeutic targeting in AML

Tobacco chewing and female oral cavity cancer risk in Karunagappally cohort, India

This study examined oral cancer in a cohort of 78 140 women aged 30–84 years in Karunagappally, Kerala, India, on whom baseline information was collected on lifestyle, including tobacco chewing, and sociodemographic factors during the period 1990–1997. By the end of 2005, 92 oral cancer cases were identified by the Karunagappally Cancer Registry. Poisson regression analysis of grouped data, taking into account age and income, showed that oral cancer incidence was strongly related to daily frequency of tobacco chewing (P<0.001) and was increased 9.2-fold among women chewing tobacco 10 times or more a day. The risk increased with the duration of tobacco chewing during the first 20 years of tobacco chewing. Age at starting tobacco chewing was not significantly related to oral cancer risk. This is the first cohort study of oral cancer in relation to tobacco chewing among women

Grape Seed Proanthocyanidins Inhibit Melanoma Cell Invasiveness by Reduction of PGE2 Synthesis and Reversal of Epithelial-to-Mesenchymal Transition

Melanoma is the leading cause of death from skin disease due, in large part, to its propensity to metastasize. We have examined the effect of grape seed proanthocyanidins (GSPs) on melanoma cancer cell migration and the molecular mechanisms underlying these effects using highly metastasis-specific human melanoma cell lines, A375 and Hs294t. Using in vitro cell invasion assays, we observed that treatment of A375 and Hs294t cells with GSPs resulted in a concentration-dependent inhibition of invasion or cell migration of these cells, which was associated with a reduction in the levels of cyclooxygenase (COX)-2 expression and prostaglandin (PG) E2 production. Treatment of cells with celecoxib, a COX-2 inhibitor, or transient transfection of melanoma cells with COX-2 small interfering RNA, also inhibited melanoma cell migration. Treatment of cells with 12-O-tetradecanoylphorbol-13-acetate, an inducer of COX-2, enhanced the phosphorylation of ERK1/2, a protein of mitogen-activated protein kinase family, and subsequently cell migration whereas both GSPs and celecoxib significantly inhibited 12-O-tetradecanoylphorbol-13-acetate -promoted cell migration as well as phosphorylation of ERK1/2. Treatment of cells with UO126, an inhibitor of MEK, also inhibited the migration of melanoma cells. Further, GSPs inhibited the activation of NF-κB/p65, an upstream regulator of COX-2, in melanoma cells, and treatment of cells with caffeic acid phenethyl ester, an inhibitor of NF-κB, also inhibited cell migration. Additionally, inhibition of melanoma cell migration by GSPs was associated with reversal of epithelial-mesenchymal transition process, which resulted in an increase in the levels of epithelial biomarkers (E-cadherin and cytokeratins) while loss of mesenchymal biomarkers (vimentin, fibronectin and N-cadherin) in melanoma cells. Together, these results indicate that GSPs have the ability to inhibit melanoma cell invasion/migration by targeting the endogenous expression of COX-2 and reversing the process of epithelial-to-mesenchymal transition

Grape Seed Proanthocyanidins Inhibit the Invasiveness of Human HNSCC Cells by Targeting EGFR and Reversing the Epithelial-To-Mesenchymal Transition

Head and neck squamous cell carcinoma (HNSCC) is responsible for approximately 20,000 deaths per year in the United States. Most of the deaths are due to the metastases. To develop more effective strategies for the prevention of metastasis of HNSCC cells, we have determined the effect of grape seed proanthocyanidins (GSPs) on the invasive potential of HNSCC cell and the mechanisms underlying these effects using OSC19 cells as an in vitro model. Using cell invasion assays, we established that treatment of the OSC19 cells with GSPs resulted in a dose-dependent inhibition of cell invasion. EGFR is over-expressed in 90% of HNSCCs and the EGFR inhibitors, erlotinib and gefitinib, are being explored as therapies for this disease. We found that GSPs treatment reduced the levels of expression of EGFR in the OSC19 cells as well as reducing the activation of NF-κB/p65, a downstream target of EGFR, and the expression of NF-κB-responsive proteins. GSPs treatment also reduced the activity of ERK1/2, an upstream regulator of NF-κB and treatment of the cells with caffeic acid phenethyl ester, an inhibitor of NF-κB, inhibited cell invasion. Overexpression of EGFR and high NF-κB activity play a key role in the epithelial-to-mesenchymal transition, which is of critical importance in the processes underlying metastasis, and we found treatment with GSPs enhanced the levels of epithelial (E-cadherin, cytokeratins and desmoglein-2) and reduced the levels of mesenchymal (vimentin, fibronectin, N-cadherin and Slug) biomarkers in the OSC19 cells. These results indicate that GSPs have the ability to inhibit HNSCC cell invasion, and do so by targeting the expression of EGFR and activation of NF-κB as well as inhibiting the epithelial-to-mesenchymal transition

The NKF-NUS hemodialysis trial protocol - a randomized controlled trial to determine the effectiveness of a self management intervention for hemodialysis patients

<p>Abstract</p> <p>Background</p> <p>Poor adherence to treatment is common in patients on hemodialysis which may increase risk for poor clinical outcomes and mortality. Self management interventions have been shown to be effective in improving compliance in other chronic populations. The aim of this trial is to evaluate the effectiveness of a recently developed group based self management intervention for hemodialysis patients compared to standard care.</p> <p>Methods/Design</p> <p>This is a multicentre parallel arm block randomized controlled trial (RCT) of a four session group self management intervention for hemodialysis patients delivered by health care professionals compared to standard care. A total of 176 consenting adults maintained on hemodialysis for a minimum of 6 months will be randomized to receive the self management intervention or standard care. Primary outcomes are biochemical markers of clinical status and adherence. Secondary outcomes include general health related quality of life, disease-specific quality of life, mood, self efficacy and self-reported adherence. Outcomes will be measured at baseline, immediately post-intervention and at 3 and 9 months post-intervention by an independent assessor and analysed on intention to treat principles with linear mixed-effects models across all time points. A qualitative component will examine which aspects of program participants found particularly useful and any barriers to change.</p> <p>Discussion</p> <p>The NKF-NUS intervention builds upon previous research emphasizing the importance of empowering patients in taking control of their treatment management. The trial design addresses weaknesses of previous research by use of an adequate sample size to detect clinically significant changes in biochemical markers, recruitment of a sufficiently large representative sample, a theory based intervention and careful assessment of both clinical and psychological endpoints at various follow up points. Inclusion of multiple dependent variables allows us to assess the broader impact on the intervention including both hard end points as well as patient reported outcomes. This program, if found to be effective, has the potential to be implemented within the existing renal services delivery model in Singapore, particularly as this is being delivered by health care professionals already working with hemodialysis patients in these settings who are specifically trained in facilitating self management in renal patients.</p> <p>Trial registration</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRTN31434033">ISRTN31434033</a></p

Cellular Immune Responses to Nine Mycobacterium tuberculosis Vaccine Candidates following Intranasal Vaccination

BACKGROUND: The identification of Mycobacterium tuberculosis vaccines that elicit a protective immune response in the lungs is important for the development of an effective vaccine against tuberculosis. METHODS AND PRINCIPAL FINDINGS: In this study, a comparison of intranasal (i.n.) and subcutaneous (s.c.) vaccination with the BCG vaccine demonstrated that a single moderate dose delivered intranasally induced a stronger and sustained M. tuberculosis-specific T-cell response in lung parenchyma and cervical lymph nodes of BALB/c mice than vaccine delivered subcutaneously. Both BCG and a multicomponent subunit vaccine composed of nine M. tuberculosis recombinant proteins induced strong antigen-specific T-cell responses in various local and peripheral immune compartments. Among the nine recombinant proteins evaluated, the alanine proline rich antigen (Apa, Rv1860) was highly antigenic following i.n. BCG and immunogenic after vaccination with a combination of the nine recombinant antigens. The Apa-induced responses included induction of both type 1 and type 2 cytokines in the lungs as evaluated by ELISPOT and a multiplexed microsphere-based cytokine immunoassay. Of importance, i.n. subunit vaccination with Apa imparted significant protection in the lungs and spleen of mice against M. tuberculosis challenge. Despite observed differences in the frequencies and location of specific cytokine secreting T cells both BCG vaccination routes afforded comparable levels of protection in our study. CONCLUSION AND SIGNIFICANCE: Overall, our findings support consideration and further evaluation of an intranasally targeted Apa-based vaccine to prevent tuberculosis

The plant-based immunomodulator curcumin as a potential candidate for the development of an adjunctive therapy for cerebral malaria

The clinical manifestations of cerebral malaria (CM) are well correlated with underlying major pathophysiological events occurring during an acute malaria infection, the most important of which, is the adherence of parasitized erythrocytes to endothelial cells ultimately leading to sequestration and obstruction of brain capillaries. The consequent reduction in blood flow, leads to cerebral hypoxia, localized inflammation and release of neurotoxic molecules and inflammatory cytokines by the endothelium. The pharmacological regulation of these immunopathological processes by immunomodulatory molecules may potentially benefit the management of this severe complication. Adjunctive therapy of CM patients with an appropriate immunomodulatory compound possessing even moderate anti-malarial activity with the capacity to down regulate excess production of proinflammatory cytokines and expression of adhesion molecules, could potentially reverse cytoadherence, improve survival and prevent neurological sequelae. Current major drug discovery programmes are mainly focused on novel parasite targets and mechanisms of action. However, the discovery of compounds targeting the host remains a largely unexplored but attractive area of drug discovery research for the treatment of CM. This review discusses the properties of the plant immune-modifier curcumin and its potential as an adjunctive therapy for the management of this complication

Dietary phytochemicals, HDAC inhibition, and DNA damage/repair defects in cancer cells

Genomic instability is a common feature of cancer etiology. This provides an avenue for therapeutic intervention, since cancer cells are more susceptible than normal cells to DNA damaging agents. However, there is growing evidence that the epigenetic mechanisms that impact DNA methylation and histone status also contribute to genomic instability. The DNA damage response, for example, is modulated by the acetylation status of histone and non-histone proteins, and by the opposing activities of histone acetyltransferase and histone deacetylase (HDAC) enzymes. Many HDACs overexpressed in cancer cells have been implicated in protecting such cells from genotoxic insults. Thus, HDAC inhibitors, in addition to unsilencing tumor suppressor genes, also can silence DNA repair pathways, inactivate non-histone proteins that are required for DNA stability, and induce reactive oxygen species and DNA double-strand breaks. This review summarizes how dietary phytochemicals that affect the epigenome also can trigger DNA damage and repair mechanisms. Where such data is available, examples are cited from studies in vitro and in vivo of polyphenols, organosulfur/organoselenium compounds, indoles, sesquiterpene lactones, and miscellaneous agents such as anacardic acid. Finally, by virtue of their genetic and epigenetic mechanisms, cancer chemopreventive agents are being redefined as chemo- or radio-sensitizers. A sustained DNA damage response coupled with insufficient repair may be a pivotal mechanism for apoptosis induction in cancer cells exposed to dietary phytochemicals. Future research, including appropriate clinical investigation, should clarify these emerging concepts in the context of both genetic and epigenetic mechanisms dysregulated in cancer, and the pros and cons of specific dietary intervention strategies