Nanostring-based multigene assay to predict recurrence for gastric cancer patients after surgery

10.1371/journal.pone.0090133PLoS ONE93-POLN

PER2 Variation is Associated with Diurnal Preference in a Korean Young Population

The PER2 gene has been reported to influence diurnal preference. In this study, we have attempted to characterize the associations between the PER2 gene polymorphisms and diurnal preference in a population of healthy young subjects, controlling for the social and environmental confounding factors. Subjects were 299 students in a college, carefully selected to be mentally and physically healthy. All subjects completed the 13-item composite scale for morningness (CSM). PER2 gene polymorphisms were genotyped by PCR-based methods. Genotype and allele carrier status of a PER2 G3853A polymorphism (rs934945) were associated with CSM scores. Carriers of the 3853G allele showed significantly higher CSM scores (P = 0.004, P = 0.009, and P = 0.001; total, morningness, and activity plan, respectively). There were no significant differences on CSM scores among genotypes and allele status of PER2 rs2304672. This result indicates that rs934945 of PER2 may be associated with diurnal preference in a Korean healthy population

The Role of p300 Histone Acetyltransferase in UV-Induced Histone Modifications and MMP-1 Gene Transcription

Matrix metalloproteinase (MMP)-1 promotes ultraviolet (UV)-triggered long-term detrimental effects such as cancer formation and premature skin aging. Although histone modifications may play a crucial role in the transcriptional regulation of MMP-1, the relationship between UV-induced histone modification and MMP-1 expression is not completely understood. Here, we identify regulators of histone acetylation that may link UV-mediated DNA damage and MMP-1 induction by UV in cultured human dermal fibroblasts (HDFs) in vitro. UV irradiation of HDFs induced MMP-1 expression and increased the level of phosphorylation of H2AX (γ-H2AX), p53 and the acetylation of histone H3 (acetyl-H3). Total histone deacetylase (HDAC) enzymatic activity was decreased by UV irradiation, while histone acetyltransferase (HAT) activity was increased. Suppression of p300 histone acetyltransferase (p300HAT) activity by the p300HAT inhibitor anacardic acid (AA) or by down-regulation of p300 by siRNA prevented UV-induced MMP-1 expression and inhibited UV-enhanced γ-H2AX, p53 level, and acetyl-H3. Using chromatin immunoprecipitation assays, we observed that γ-H2AX, p53, acetyl-H3, p300 and c-Jun were consistently recruited by UV to a distinct region (−2067/−1768) adjacent to the p300 binding site (−1858/−1845) in the MMP-1 promoter. In addition, these recruitments of γ-H2AX, p53, acetyl-H3, p300 and c-Jun to the p300-2 site were significantly abrogated by post-treatment with AA. Furthermore, overexpression of p300 increased the basal and UV-induced MMP-1 promoter activity. Our results suggest that p300HAT plays a critical role in the transcriptional regulation of MMP-1 by UV

A Cell-based Computational Modeling Approach for Developing Site-Directed Molecular Probes

Modeling the local absorption and retention patterns of membrane-permeant small molecules in a cellular context could facilitate development of site-directed chemical agents for bioimaging or therapeutic applications. Here, we present an integrative approach to this problem, combining in silico computational models, in vitro cell based assays and in vivo biodistribution studies. To target small molecule probes to the epithelial cells of the upper airways, a multiscale computational model of the lung was first used as a screening tool, in silico. Following virtual screening, cell monolayers differentiated on microfabricated pore arrays and multilayer cultures of primary human bronchial epithelial cells differentiated in an air-liquid interface were used to test the local absorption and intracellular retention patterns of selected probes, in vitro. Lastly, experiments involving visualization of bioimaging probe distribution in the lungs after local and systemic administration were used to test the relevance of computational models and cell-based assays, in vivo. The results of in vivo experiments were consistent with the results of in silico simulations, indicating that mitochondrial accumulation of membrane permeant, hydrophilic cations can be used to maximize local exposure and retention, specifically in the upper airways after intratracheal administration

Inhibition of Akt activity induces the mesenchymal-to-epithelial reverting transition with restoring E-cadherin expression in KB and KOSCC-25B oral squamous cell carcinoma cells

<p>Abstract</p> <p>Background</p> <p>The Akt/PKB family of kinases is frequently activated in human cancers, including oral squamous cell carcinoma (OSCC). Akt-induced epithelial-to-mesenchymal transition (EMT) involves downregulation of E-cadherin, which appears to result from upregulation of the transcription repressor Snail. Recently, it was proposed that carcinoma cells, especially in metastatic sites, could acquire the mesenchymal-to-epithelial reverting transition (MErT) in order to adapt the microenvironments and re-expression of E-cadherin be a critical indicator of MErT. However, the precise mechanism and biologic or clinical importance of the MErT in cancers have been little known. This study aimed to investigate whether Akt inhibition would restore the expression of E-cadherin and β-catenin, reduce that of Vimentin, and induce the MErT in OSCC cells with low or negative expression of E-cadherin. We also investigate whether inhibition of Akt activity would affect the E-cadherin repressors and signaling molecules like NF-κB, ERK, and p38.</p> <p>Methods</p> <p>We screened several OSCC cell lines in order to select suitable cell line models for inducing MErT, using immunoblotting and methylation specific-PCR. We examined whether Akt inhibitor phosphatidylinositol ether lipid analogues (PIA) treatment would restore the expression of E-cadherin and β-catenin, reduce that of Vimentin, and induce the MErT in KB and KOSCC-25B cells using RT-PCR, immunoblotting, immunofluorescence analysis, and <it>in vitro </it>migration assay. We also investigated whether inhibition of Akt activity would affect the E-cadherin repressors, including Snail, Twist, and SIP-1/ZEB-2 and signaling molecules like NF-κB, ERK, JNK, and p38 using RT-PCR, immunoblotting, and immunofluorescence analysis.</p> <p>Results</p> <p>Of the 7 OSCC cell lines, KB and KOSCC-25B showed constitutively activated phosphorylated Akt and low or negative expression of E-cadherin. Inhibition of Akt activity by PIA decreased NF-κB signaling, but did not affect phosphorylation of ERK, JNK, and p38 in KB and KOSCC-25B cells. Akt inhibition led to downregulation of Snail and Twist expression. In contrast, inhibition of Akt activity by PIA did not induce any changes in SIP-1/ZEB-2 expression. PIA treatment induced the expression of E-cadherin and β-catenin, reduce that of Vimentin, restored their epithelial morphology of a polygonal shape, and reduced tumor cell migration in KB and KOSCC-25B cells, which was the corresponding feature of MErT.</p> <p>Conclusion</p> <p>All of these findings suggest that Akt inhibition could induce the MErT through decreased NF-κB signaling and downregulation of Snail and Twist in OSCC cells. A strategy involving Akt inhibition might be a useful therapeutic tool in controlling cancer dissemination and metastasis in oral cancer patients.</p

Analysis of the dihydrofolate reductase-thymidylate synthase gene sequences in Plasmodium vivax field isolates that failed chloroquine treatment

<p>Abstract</p> <p>Background</p> <p>To use pyrimethamine as an alternative anti-malarial drug for chloroquine-resistant malaria parasites, it was necessary to determine the enzyme's genetic variation in dihydrofolate reductase-thymidylate syntase (DHFR-TS) among Korean strains.</p> <p>Methods</p> <p>Genetic variation of <it>dhfr-ts </it>genes of <it>Plasmodium vivax </it>clinical isolates from patients who did not respond to drug treatment (<it>n </it>= 11) in Korea were analysed. The genes were amplified using the polymerase chain reaction (PCR) with genomic DNA as a template.</p> <p>Results</p> <p>Sequence analysis showed that the open reading frame (ORF) of 1,857 nucleotides encoded a deduced protein of 618 amino acids (aa). Alignment with the DHFR-TS genes of other malaria parasites showed that a 231-residue DHFR domain and a 286-residue TS domain were seperated by a 101-aa linker region. This ORF shows 98.7% homology with the <it>P. vivax </it>Sal I strain (XM001615032) in the DHFR domain, 100% in the linker region and 99% in the TS domain. Comparison of the DHFR sequences from pyrimethamine-sensitive and pyrimethamine-resistant <it>P. vivax </it>isolates revealed that nine isolates belonged to the sensitive strain, whereas two isolates met the criteria for resistance. In these two isolates, the amino acid at position 117 is changed from serine to asparagine (S117N). Additionally, all Korean isolates showed a deletion mutant of THGGDN in short tandem repetitive sequences between 88 and 106 amino acid.</p> <p>Conclusions</p> <p>These results suggest that sequence variations in the DHFR-TS represent the prevalence of antifolate-resistant <it>P. vivax </it>in Korea. Two of 11 isolates have the Ser to Asn mutation in codon 117, which is the major determinant of pyrimethamine resistance in <it>P. vivax</it>. Therefore, the introduction of pyrimethamine for the treatment of chloroquine-resistant vivax malaria as alternative drug in Korea should be seriously considered.</p

Prognostic significance of CD44s expression in resected non-small cell lung cancer

<p>Abstract</p> <p>Background</p> <p>CD44s is a cell adhesion molecule known to mediate cellular adhesion to the extracellular matrix, a prerequisite for tumor cell migration. CD44s plays an important role in invasion and metastasis of various cancers. In the present study, we sought to determine whether CD44s is involved in clinical outcomes of patients with resected non-small cell lung cancer (NSCLC).</p> <p>Methods</p> <p>Using immunohistochemical staining, we investigated CD44s protein expression using tissue array specimens from 159 patients with resected NSCLC (adenocarcinoma (AC; <it>n </it>= 82) and squamous cell carcinoma (SCC; <it>n </it>= 77). Additionally, the immunoreactivity of cyclooxygenase (COX)-2 was also studied. The clinicopathological implications of these molecules were analyzed statistically.</p> <p>Results</p> <p>High CD44s expression was detected more frequently in NSCLC patients with SCC (66/72; 91.7%) than in those with AC histology (<it>P <</it>0.001). Additionally, high CD44s expression was significant correlated with more advanced regional lymph node metastasis (<it>P </it>= 0.021). In multivariate analysis of survival in NSCLC patients with AC histology, significant predictors were lymph node metastasis status (<it>P </it>< 0.001), high-grade tumor differentiation (<it>P = </it>0.046), and high CD44s expression (<it>P = </it>0.014). For NSCLC patients with SCC histology, the significant predictor was a more advanced tumor stage (<it>P = </it>0.015). No significant association was found between CD44s and clinical outcome (<it>P </it>= 0.311).</p> <p>Conclusions</p> <p>High CD44s expression was a negative prognostic marker with significance in patients with resected NSCLC, particularly those with AC histology, and was independent of tumor stage.</p