In-Silico Molecular Modeling Studies to Identify Novel Potential Inhibitors of HPV E6 Protein

The etiological agent of some anogenital tract cancers is infection with the high-risk human papillomavirus (HPV). Currently, prophylactic vaccines against HPV have been validated, but the presence of drug treatment directed against the infection and its oncogenic effects remain essential. Among the best drug targets, viral oncoprotein E6 has been identified as a key factor in cell immortalization and tumor progression in HPV-positive cells. E6, through interaction with the cellular ubiquitin ligase E6AP, can promote the degradation of p53, a tumor suppressor protein. Therefore, suppression of the creation of the E6-E6AP complex is one of the essential strategies to inhibit the survival and proliferation of infected cells. In the present study, we proposed an in-silico approach for the discovery of small molecules with inhibitory activity on the E6-E6AP interaction. The first three compounds (F0679-0355, F33774-0275, and F3345-0326) were selected on the basis of virtual screening and prediction of the molecules' ADMET properties and docking with E6 protein, these molecules were selected for further study by investigating their stability in the E6 complex and their inhibitory effect on the E6-E6AP interaction by molecular dynamics (MD) simulation. The identified molecules thus represent a good starting point for the development of anti-HPV drugs.

Association between overweight and anemia in Moroccan adolescents: a cross-sectional study

Introduction

obesity and anemia remain global public health problems, having major negative effects on human health. We aimed to estimate the prevalence of anemia and investigate its association with overweight/obesity and excess body fat among Moroccan adolescents.

Methods

a total of 292 adolescents aged 11-17 years were recruited. Body mass index (BMI) and waist circumference (WC) were determined using standardized equipment. Body fat mass was measured by bioelectrical impedance analysis. Hemoglobin concentration was measured by the HemoCue method.

Results

the overall prevalence of anemia was 13.7%. Anemia was more common among overweight/obese participants (15.2%) compared to non-overweight participants (12.8%). Overweight/obese boys were more likely to experience anemia than their non-overweight peers (odds ratio (OR): 1.49; 95% confidence interval (95%CI): 0.51-4.41). Similarly, anemia likelihood was higher among individuals having excess body fat than those who do not have excess body fat, particularly among girls (OR: 1.64; 95%CI: 0.69-3.87). Excess body fat was also significantly associated with lower hemoglobin concentration in both the total sample and girls (P=0.014, and P=0.041, respectively). Overall, increased BMI, WC, fat mass, and percent body fat were associated with reduced hemoglobin concentrations. There was a significant negative correlation between hemoglobin concentration and BMI among anemic girls (P=0.023).

Conclusion

elevated BMI and body fat level were associated with lower hemoglobin concentrations and anemia. Further studies are needed to delineate the basis of such associations, and if these findings are confirmed, the guidelines for screening for anemia may need to be modified to include overweight/obesity as a risk factor.

HPV16 L1 diversity and its potential impact on the vaccination-induced immunity

Human Papillomavirus 16 (HPV16) is the most oncogenic HPV and the most associated genotype with cervical cancer development and progression. Currently, all developed vaccines are targeting HPV16 and were designed based on the major L1 capsid protein. Thus, evaluation of the diversity of HPV16 L1 sequence, mainly in the antigenic regions, will be of a great interest to assess the efficacy of the prophylactic vaccines and to predict the impact of genetic variations in these regions on the vaccination-induced immunity. A total of 377 HPV16 L1 sequences, published in public domain GenBank database, from the Americas, Africa, Asia, and Europe were collected and assembled. A total of 626 mutation events affecting 83 distinct nucleotides into the five antigenic regions of L1 gene of HPV16 were reported, and most SNPs were located in DE (27.38%, 23/83) and FG (31%, 26/83) loops. Overall, 4 mutations were frequently found in HPV16 sequences: T176N and N181T in EF loop; A266T in the FG loop and T353P/I/N HI loop. Of particular interest, some SNPs are ubiquitous and were found in all populations whereas others were population specific and their presence was limited to one or 2 at the maximum. Association between mutations in the antigenic regions and ethnicity was also investigated and showed that mutations in BC and DE loops were present with no significant difference in sequences from Europe, Asia, America and Africa. However, most mutations in FG loop are reported in sequences from European cases and are less pronounced in cases from America and Asia, whereas mutations EF and HI loops prevail in Asian cases. These data highlight a high number of variant amino acid residues that could affect the vaccination-induced immunity and impact the effectiveness of the prophylactic vaccination to fight against HPV, warranting the need of further investigation for vaccines and natural history studies of HPV16.

Tomentosin Induces Telomere Shortening and Caspase-Dependant Apoptosis in Cervical Cancer Cells

Tomentosin, a natural sesquiterpene lactone purified from of Inula viscosa L., was investigated for its anti-proliferative, telomere shortening, and apoptotic effects on human cervical cancer HeLa and SiHa cell lines. Tomentosin was found to inhibit the growth of SiHa and HeLa cell lines in dose and time-dependent manner (IC₅₀ values of 7.10 ± 0.78 μM and 5.87 ± 0.36 μM, respectively after 96 h of treatment). As evidenced by TTAGGG telomere length assay, tomentosin target specifically the telomeric overhang lengthening. This was confirmed by the evaluation of the cytotoxic effects of tomentosin in the foetal fibroblast Wi38 and JW10 cells which were derived from Wi38 and express hTERT, the telomerase catalytic subunit. We found that JW10 cells are 4.7-fold more sensitive to tomentosin which argues for telomere as its specific target. Furthermore, we found that tomentosin mediate this cytotoxic effect by inducing apoptosis and cell cycle arrest at G2/M phase. Morphological features of treated cells, as evidenced by Hoechst 33324 staining, revealed that the cytotoxic effect was due to induction of apoptosis. This was accompanied by pro-caspase-3 cleavage, an increase in caspase-3 activity and a cleavage of poly (ADP-ribose) polymerase (PARP). Moreover, tomentosin induced a decrease in mitochondrial membrane potential (ΔΨm) and an increase in reactive oxygen species (ROS), accompanied by a decrease in Bcl-2 expression. This indicates that tomentosin-induced apoptosis may involve a mitochondria-mediated signaling pathway. This study provides the first evidence that tomentosin targets telomere machinery and induces apoptosis in cervical cancer cells. The molecular mechanism underlying tomentosin-induced apoptosis may involve a mitochondria-mediated signaling pathway. J. Cell. Biochem. 118: 1689-1698, 2017. © 2016 Wiley Periodicals, Inc.

Transcriptome Changes in Hirschfeldia incana in Response to Lead Exposure

Hirschfeldia incana, a pseudometallophyte belonging to the Brassicaceae family and widespread in the Mediterranean region, was selected for its ability to grow on soils contaminated by lead (Pb). The global comparison of gene expression using microarrays between a plant susceptible to Pb (Arabidopsis thaliana) and a Pb tolerant plant (H. incana) enabled the identification of a set of specific genes expressed in response to lead exposure. Three groups of genes were particularly over-represented by the Pb exposure in the biological processes categorized as photosynthesis, cell wall, and metal handling. Each of these gene groups was shown to be directly involved in tolerance or in protection mechanisms to the phytotoxicity associated with Pb. Among these genes, we demonstrated that MT2b, a metallothionein gene, was involved in lead accumulation, confirming the important role of metallothioneins in the accumulation and the distribution of Pb in leaves. On the other hand, several genes involved in biosynthesis of ABA were shown to be up-regulated in the roots and shoots of H. incana treated with Pb, suggesting that ABA-mediated signaling is a possible mechanism in response to Pb treatment in H. incana. This latest finding is an important research direction for future studies.

Lead tolerance and accumulation in Hirschfeldia incana, a Mediterranean Brassicaceae from metalliferous mine spoils

Lead is a heavy metal of particular concern with respect to environmental quality and health. The lack of plant species that accumulate and tolerate Pb is a limiting factor to understand the molecular mechanisms involved in Pb tolerance. In this study we identified Hirschfeldia incana, a Brassicaceae collected from metalliferous mine spoils in Morocco, as a Pb accumulator plant. H. incana exhibited high Pb accumulation in mine soils and in hydroponic cultures. Major Pb accumulation occurred in the roots and a part of Pb translocated from the roots to the shoots, even to the siliques. These findings demonstrated that H. incana is a Pb accumulator species. The expression of several candidate genes after Pb-exposure was measured by quantitative PCR and two of them, HiHMA4 and HiMT2a, coding respectively for a P1B-type ATPase and a metallothionein, were particularly induced by Pb-exposure in both roots and leaves. The functional characterization of HiHMA4 and HiMT2a was achieved using Arabidopsis T-DNA insertional mutants. Pb content and primary root growth analysis confirmed the role of these two genes in Pb tolerance and accumulation. H. incana could be considered as a good experimental model to identify genes involved in lead tolerance and accumulation in plants.

Effect of lead on root growth

Lead (Pb) is one of the most widespread heavy metal contaminant in soils. It is highly toxic to living organisms. Pb has no biological function but can cause morphological, physiological, and biochemical dysfunctions in plants. Plants have developed a wide range of tolerance mechanisms that are activated in response to Pb exposure. Pb affects plants primarily through their root systems. Plant roots rapidly respond either (i) by the synthesis and deposition of callose, creating a barrier that stops Pb entering (ii) through the uptake of large amounts of Pb and its sequestration in the vacuole accompanied by changes in root growth and branching pattern or (iii) by its translocation to the aboveground parts of plant in the case of hyperaccumulators plants. Here we review the interactions of roots with the presence of Pb in the rhizosphere and the effect of Pb on the physiological and biochemical mechanisms of root development.