Small interfering RNA targeting CDC25B inhibits liver tumor growth in vitro and in vivo

<p>Abstract</p> <p>Background</p> <p>Using gene expression profiling, we previously identified CDC25B to be significantly highly expressed in hepatocellular carcinoma (HCC) compared to non-tumor liver. CDC25B is a cell cycle-activating phosphatase that positively regulates the activity of cyclin-dependent kinases, and is over-expressed in a variety of human malignancies. In this study, we validated the over-expression of CDC25B in HCC, and further investigated its potential as a therapeutic target for the management of HCC.</p> <p>Results</p> <p>Quantitative real-time polymerase chain reaction and immunohistochemical staining of patient samples confirmed the significant over-expression of CDC25B in HCC compared to non-tumor liver samples (<it>P </it>< 0.001). Thus, intefering with the expression and activity of CDC25B may be a potential way to intervene with HCC progression. We used RNA interference to study the biological effects of silencing CDC25B expression in HCC cell lines (Hep3B and Hep40), in order to validate its potential as a therapeutic target. Using small oligo siRNAs targeting the coding region of CDC25B, we effectively suppressed CDC25B expression by up to 90%. This was associatetd with significant reductions in cell growth rate, cell migration and invasion through the matrigel membrane, and caused significant cell cycle delay at the G2 phase. Finally, suppression of CDC25B significantly slowed the growth of Hep40 xenografts in nude mice.</p> <p>Conclusion</p> <p>Our data provide evidence that the inhibition of CDC25B expression and activity lead to suppression of tumor cell growth and motility, and may therefore be a feasible approach in the clinical management of HCC.</p

Blockade of Wnt-1 signaling leads to anti-tumor effects in hepatocellular carcinoma cells

<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) is an aggressive cancer, and is the third leading cause of cancer death worldwide. Standard therapy is ineffective partly because HCC is intrinsically resistant to conventional chemotherapy. Its poor prognosis and limited treatment options make it critical to develop novel and selective chemotherapeutic agents. Since the Wnt/β-catenin pathway is essential in HCC carcinogenesis, we studied the inhibition of Wnt-1-mediated signaling as a potential molecular target in HCC.</p> <p>Results</p> <p>We demonstrated that Wnt-1 is highly expressed in human hepatoma cell lines and a subgroup of human HCC tissues compared to paired adjacent non-tumor tissues. An anti-Wnt-1 antibody dose-dependently decreased viability and proliferation of Huh7 and Hep40 cells over-expressing Wnt-1 and harboring wild type β-catenin, but did not affect normal hepatocytes with undetectable Wnt-1 expression. Apoptosis was also observed in Huh7 and Hep40 cells after treatment with anti-Wnt-1 antibody. In these two cell lines, the anti-Wnt-1 antibody decreased β-catenin/Tcf4 transcriptional activities, which were associated with down-regulation of the endogenous β-catenin/Tcf4 target genes c-Myc, cyclin D1, and survivin. Intratumoral injection of anti-Wnt-1 antibody suppressed <it>in vivo </it>tumor growth in a Huh7 xenograft model, which was also associated with apoptosis and reduced c-Myc, cyclin D1, and survivin expressions.</p> <p>Conclusion</p> <p>Our results suggest that Wnt-1 is a survival factor for HCC cells, and that the blockade of Wnt-1-mediated signaling may offer a potential pathway-specific therapeutic strategy for the treatment of a subgroup of HCC that over-expresses Wnt-1.</p

Soluble Frizzled-7 receptor inhibits Wnt signaling and sensitizes hepatocellular carcinoma cells towards doxorubicin

Abstract Background There are limited therapeutic options for hepatocellular carcinoma (HCC), the most common liver malignancy worldwide. Recent studies have identified the Frizzled-7 receptor (FZD7), important for activation of Wnt-mediated signaling, as a potential therapeutic target for HCC and other cancers. Methods We hypothesized that the extracellular domain of FZD7 (sFZD7) would be a clinically more relevant therapeutic modality than previously studied approaches to target FZD7. We expressed and purified sFZD7 from E. coli, and tested its functional activity to interact with Wnt3, its ability to inhibit Wnt3-mediated signaling, and its potential for combinatorial therapy in HCC. Results sFZD7 pulled down Wnt3 from Huh7 cells, and decreased β-catenin/Tcf4 transcriptional activity in HCC cells. In vitro, sFZD7 dose-dependently decreased viability of three HCC cell lines (HepG2, Hep40, and Huh7, all with high FZD7 and Wnt3 mRNA), but had little effect on normal hepatocytes from three donors (all with low level FZD7 and Wnt3 mRNA). When combined with doxorubicin, sFZD7 enhanced the growth inhibitory effects of doxorubicin against HCC cells in vitro, and against Huh7 xenografts in vivo. Reduced expressions of c-Myc, cyclin D1, and survivin were observed in vitro and in vivo. Additionally, sFZD7 altered the levels of phosphorylated AKT and ERK1/2 induced by doxorubicin treatment in vitro, suggesting that several critical pathways are involved in the chemosensitizing effect of sFZD7. Conclusions We propose that sFZD7 is a feasible therapeutic agent with specific activity, which can potentially be combined with other chemotherapeutic agents for the improved management of HCC.</p

Community awareness of bird flu and the practice of backyard poultry in a North-Central State of Nigeria

Introduction. The practice of backyard poultry is a very common practice in many homes in Nigeria. Birds raised at home are usually free ranged, which increases close contact between man and birds, thus increasing the risk of transmission of avian influenza virus to man. This study investigated the awareness of bird flu infection and identifies risk factors associated with the practice of backyard/free ranged poultry among the residents of a state in Northern Nigeria. Methods. This cross-sectional study was carried out in Kwara State using 130 wards selected through cluster sampling technique. Households in each ward were sampled through systematic random sampling technique using the primary health care house numbering register. Semi-structured questionnaire was used to generate relevant information through interview and 650 participants consented and were used for the study. Results. Most of the respondents 604 (92.9%) kept birds in their homes and one-third 204 (33.8%) of this group knew that infection from birds can be transmitted to man. However, less than a third186 (30.8%) of those who keep birds were aware of avian influenza (AI) infection. Out of the 186 respondents, 78 (41.9%) had experienced massive bird deaths in the preceding year prior to the interview. Less than half 81 (43.5%) were willing to report AI or massive deaths occurring in flocks of their birds to designated officers / authority. During outbreaks with massive deaths in birds some of the respondents sold infected live birds 45 (57.7%), few slaughtered and dressed the birds before sale 11 (14.1%), while some slaughtered and consumed the birds in their families 19 (24.4%). Conclusion. The practice of backyard poultry is very high with little knowledge and awareness of mechanism and risk of infection associated with it. This was also reflected in their attitude towards reporting of outbreaks in birds. Public awareness campaign and home visit by environmental and veterinary officers are important strategies that can prevent AI infection transmission among domestic birds and man

Community survey on blood donation practices in a northern state of Nigeria

Introduction. Volunteer blood donors account for less than half of the blood supply in developing countries; and few countries have mobilized efforts to encourage voluntary blood donation (VBD). The objective of this study was to determine the knowledge and blood donation practices among adults in a state in Northern Nigeria. Methods. Descriptive cross sectional study using multistage sampling technique was carried out among 936 respondents. Semi structured interviewer administered questionnaire was used to generate relevant data and information from the respondents. Data entry and analysis was done using EPI-info software package. Results. The knowledge of the respondents on blood donation was low. Less than half 432 (46.2%) knew some indications for blood transfusion. Two hundred and twelve (22.6%) respondents had donated blood in the past but only 1% of these were VBD while 95% were donations based on blood needs by family members, relations and friends. Few respondents 112 (12%) had received blood transfusion in the past, and the main source of blood transfused was paid commercial donors 50 (44.6%). The fear of HIV screening was a major hindrance and limitation to voluntary blood donation among respondents. Conclusion. The gaps in knowledge and practice of VBD can be addressed through public awareness campaigns, and motivational programmes such as free medical services for voluntary blood donors

Mucoadhesive Nanoparticles May Disrupt the Protective Human Mucus Barrier by Altering Its Microstructure

Mucus secretions typically protect exposed surfaces of the eyes and respiratory, gastrointestinal and female reproductive tracts from foreign entities, including pathogens and environmental ultrafine particles. We hypothesized that excess exposure to some foreign particles, however, may cause disruption of the mucus barrier. Many synthetic nanoparticles are likely to be mucoadhesive due to hydrophobic, electrostatic or hydrogen bonding interactions. We therefore sought to determine whether mucoadhesive particles (MAP) could alter the mucus microstructure, thereby allowing other foreign particles to more easily penetrate mucus. We engineered muco-inert probe particles 1 µm in diameter, whose diffusion in mucus is limited only by steric obstruction from the mucus mesh, and used them to measure possible MAP-induced changes to the microstructure of fresh human cervicovaginal mucus. We found that a 0.24% w/v concentration of 200 nm MAP in mucus induced a ∼10-fold increase in the average effective diffusivity of the probe particles, and a 2- to 3-fold increase in the fraction capable of penetrating physiologically thick mucus layers. The same concentration of muco-inert particles, and a low concentration (0.0006% w/v) of MAP, had no detectable effect on probe particle penetration rates. Using an obstruction-scaling model, we determined that the higher MAP dose increased the average mesh spacing (“pore” size) of mucus from 380 nm to 470 nm. The bulk viscoelasticity of mucus was unaffected by MAP exposure, suggesting MAP may not directly impair mucus clearance or its function as a lubricant, both of which depend critically on the bulk rheological properties of mucus. Our findings suggest mucoadhesive nanoparticles can substantially alter the microstructure of mucus, highlighting the potential of mucoadhesive environmental or engineered nanoparticles to disrupt mucus barriers and cause greater exposure to foreign particles, including pathogens and other potentially toxic nanomaterials

SEROPREVALENCE OF IMMUNOGLOBULIN IgG ANTIBODY RESPONSE TO PLASMODIUM FALCIPARUM MEROZOITE ANTIGENS AMONG CHILDREN IN MINNA, NORTH CENTRAL, NIGERIA

Objective: A cross-sectional study was carried out in a representative cohort of children in Minna aged 6 months–17 years to determine the correlation between immunoglobulin G (IgG) antibody responses to Plasmodium falciparum merozoite antigens. Methods: Plasma samples from 93 children were exposed to Enzyme-Linked Immunosorbent Assay for the measurement of IgG antibody production against P. falciparum. Results: There was a high seroprevalence of IgG antibody against P. falciparum antigens tested with 74.20%. The seroprevalence for the male category was quite higher as compared with that of the female category, though, analysis using Mann–Whitney U-test revealed IgG antibody response to P. falciparum infection in the male was significantly different as compared to the female category (p&lt;0.05). Furthermore, the prevalence of IgG antibody against P. falciparum antigen increased with age, with the lowest observed in 6 months–5 years 66.66%. Kruskal–Wallis H test showed a non-significant difference in the production of IgG antibody against P. falciparum antigen between different cohorts, and no correlation exists between them (p&gt;0.05). An evidence of more than 50% was found for the production of IgG antibody by sub-microscopic parasite. On the other hand, microscopically positive P. falciparum samples recorded more seroprevalence of 68.81% as against negative samples, though significant difference between the negative and positive P. falciparum infected samples and the production of IgG antibody was not observed (p&gt;0.05). Conclusion: This study has demonstrated a boosting immune responses by sub-microscopic parasite and also suggests a strong relationship between production of IgG antibody and malaria transmission, rather than protective immunity