Mapping of oxidative stress responses of human tumor cells following photodynamic therapy using hexaminolevulinate

<p>Abstract</p> <p>Background</p> <p>Photodynamic therapy (PDT) involves systemic or topical administration of a lesion-localizing photosensitizer or its precursor, followed by irradiation of visible light to cause singlet oxygen-induced damage to the affected tissue. A number of mechanisms seem to be involved in the protective responses to PDT, including activation of transcription factors, heat shock proteins, antioxidant enzymes and apoptotic pathways.</p> <p>Results</p> <p>In this study, we address the effects of a destructive/lethal hexaminolevulinate (HAL) mediated PDT dose on the transcriptome by using transcriptional exon evidence oligo microarrays. Here, we confirm deviations in the steady state expression levels of previously identified early defence response genes and extend this to include unreported PDT inducible gene groups, most notably the metallothioneins and histones. HAL-PDT mediated stress also altered expression of genes encoded by mitochondrial DNA (mtDNA). Further, we report PDT stress induced alternative splicing. Specifically, the ATF3 alternative isoform (deltaZip2) was up-regulated, while the full-length variant was not changed by the treatment. Results were independently verified by two different technological microarray platforms. Good microarray, RT-PCR and Western immunoblotting correlation for selected genes support these findings.</p> <p>Conclusion</p> <p>Here, we report new insights into how destructive/lethal PDT alters the transcriptome not only at the transcriptional level but also at post-transcriptional level via alternative splicing.</p

Improvement in the national genetic evaluation of warmblood riding horses by including information from related studbooks

acceptedVersio

Genetic conditions of joint Nordic genetic evaluations of lifetime competition performance in warmblood sport horses

acceptedVersio

Coancestry rate’s estimate of effective population size for genetic variability monitoring

Different methods and formulae have been suggested to estimate effective population size based on pedigree data. These methods vary in their sensitivity to various sources of bias related to heterogenous pedigree knowledge or pedigree structure. We propose here to adapt a pre-existing method estimating coancestry rate for the specific purpose of monitoring genetic variability within livestock and captive populations. Coancestry rate is computed by averaging coancestries between pairs of individuals corrected by their equivalent numbers of generations, while restricting pedigree information to a maximum number of generations. Simulation demonstrated that restricting the number of generations allows a much clearer observation of the impact of recent events on genetic variability. Restricting the number of generations for the calculation of coancestry also has less bias related to incomplete pedigree, although it may overestimate effective population size due to non-independence in family sizes across generations. This strategy was tested on the Norwegian Nordland Lyngen horse, the Colblood Trotter horse, the French Avranchin sheep, and Bresse chicken, illustrating the applications of the approach for the monitoring of genetic variability

Coancestry rate’s estimate of effective population size for genetic variability monitoring

9 Pág.Different methods and formulae have been suggested to estimate effective population size based on pedigree data. These methods vary in their sensitivity to various sources of bias related to heterogenous pedigree knowledge or pedigree structure. We propose here to adapt a pre-existing method estimating coancestry rate for the specific purpose of monitoring genetic variability within livestock and captive populations. Coancestry rate is computed by averaging coancestries between pairs of individuals corrected by their equivalent numbers of generations, while restricting pedigree information to a maximum number of generations. Simulation demonstrated that restricting the number of generations allows a much clearer observation of the impact of recent events on genetic variability. Restricting the number of generations for the calculation of coancestry also has less bias related to incomplete pedigree, although it may overestimate effective population size due to non-independence in family sizes across generations. This strategy was tested on the Norwegian Nordland Lyngen horse, the Colblood Trotter horse, the French Avranchin sheep, and Bresse chicken, illustrating the applications of the approach for the monitoring of genetic variability.The authors would like to thank the French Government for providing the secondment of Dr Gregoire Leroy to FAO.Peer reviewe

Cluster of spliceosome complex genes that were significantly altered in response to HAL-PDT

<p><b>Copyright information:</b></p><p>Taken from "Mapping of oxidative stress responses of human tumor cells following photodynamic therapy using hexaminolevulinate"</p><p>http://www.biomedcentral.com/1471-2164/8/273</p><p>BMC Genomics 2007;8():273-273.</p><p>Published online 13 Aug 2007</p><p>PMCID:PMC2045114.</p><p></p> Horizontal stripes represent genes and columns show treatment protocols. The log2-fold changes of gene ratios are color coded as shown in the bar. The three different columns represent repeated microarray experiments

Verification of MYC, ATF3 and JUN expression after HAL-PDT by Western blotting

<p><b>Copyright information:</b></p><p>Taken from "Mapping of oxidative stress responses of human tumor cells following photodynamic therapy using hexaminolevulinate"</p><p>http://www.biomedcentral.com/1471-2164/8/273</p><p>BMC Genomics 2007;8():273-273.</p><p>Published online 13 Aug 2007</p><p>PMCID:PMC2045114.</p><p></p> Cell extracts were prepared at at 1 h, 2 h and 4 h after HAL-PDT (A). Since PDT affected the expression of well-known house keeping proteins such actin (induced) and tubulin (repressed) the total protein content was measured and the gels were stained after electrophoresis, thus normalize against total protein content. The fold-changes obtained by the microarray analysis for the selected genes are presented for comparison. Fold-change of three repeated experiments presented as the mean ± St. Dev (B)

Venn diagrams of differentially altered genes/probes in response to HAL-PDT

<p><b>Copyright information:</b></p><p>Taken from "Mapping of oxidative stress responses of human tumor cells following photodynamic therapy using hexaminolevulinate"</p><p>http://www.biomedcentral.com/1471-2164/8/273</p><p>BMC Genomics 2007;8():273-273.</p><p>Published online 13 Aug 2007</p><p>PMCID:PMC2045114.</p><p></p> A, includes up-regulated and down-regulated; B, only up-regulated; C, only down-regulated genes/probes at 1, 2 and 4 h time course. Each circle represents one time point as indicated. A total number of differentially expressed genes in the group are given in the parentheses. The intersections indicate numbers of genes/probe that are shared between the different time points, i.e. the genes that were steady induced. The number in the right bottom of each square indicates a total post processed and analyzed number of genes/probes minus the number of differentially expressed genes presented in circles