Gene expression analysis after receptor tyrosine kinase activation reveals new potential melanoma proteins

<p>Abstract</p> <p>Background</p> <p>Melanoma is an aggressive tumor with increasing incidence. To develop accurate prognostic markers and targeted therapies, changes leading to malignant transformation of melanocytes need to be understood. In the <it>Xiphophorus </it>melanoma model system, a mutated version of the EGF receptor Xmrk (<it>Xiphophorus </it>melanoma receptor kinase) triggers melanomagenesis. Cellular events downstream of Xmrk, such as the activation of Akt, Ras, B-Raf or Stat5, were also shown to play a role in human melanomagenesis. This makes the elucidation of Xmrk downstream targets a useful method for identifying processes involved in melanoma formation.</p> <p>Methods</p> <p>Here, we analyzed Xmrk-induced gene expression using a microarray approach. Several highly expressed genes were confirmed by realtime PCR, and pathways responsible for their induction were revealed using small molecule inhibitors. The expression of these genes was also monitored in human melanoma cell lines, and the target gene <it>FOSL1 </it>was knocked down by siRNA. Proliferation and migration of siRNA-treated melanoma cell lines were then investigated.</p> <p>Results</p> <p>Genes with the strongest upregulation after receptor activation were FOS-like antigen 1 (<it>Fosl1</it>), early growth response 1 (<it>Egr1</it>), osteopontin (<it>Opn</it>), insulin-like growth factor binding protein 3 (<it>Igfbp3</it>), dual-specificity phosphatase 4 (<it>Dusp4</it>), and tumor-associated antigen L6 (<it>Taal6</it>). Interestingly, most genes were blocked in presence of a SRC kinase inhibitor. Importantly, we found that <it>FOSL1</it>, <it>OPN</it>, <it>IGFBP3</it>, <it>DUSP4</it>, and <it>TAAL6 </it>also exhibited increased expression levels in human melanoma cell lines compared to human melanocytes. Knockdown of <it>FOSL1 </it>in human melanoma cell lines reduced their proliferation and migration.</p> <p>Conclusion</p> <p>Altogether, the data show that the receptor tyrosine kinase Xmrk is a useful tool in the identification of target genes that are commonly expressed in Xmrk-transgenic melanocytes and melanoma cell lines. The identified molecules constitute new possible molecular players in melanoma development. Specifically, a role of FOSL1 in melanomagenic processes is demonstrated. These data are the basis for future detailed analyses of the investigated target genes.</p

JunD/AP-1-Mediated Gene Expression Promotes Lymphocyte Growth Dependent on Interleukin-7 Signal Transduction

Interleukin-7 (IL-7) is an essential cytokine for lymphocyte growth that has the potential for promoting immune reconstitution. This feature makes IL-7 an ideal candidate for therapeutic development. As with other cytokines, signaling through the IL-7 receptor induces the JAK/STAT pathway. However, the broad scope of IL-7 regulatory targets likely necessitates the use of other signaling components whose identities remain poorly defined. To this end, we used an IL-7 dependent T-cell line to examine how expression of the glycolytic enzyme, Hexokinase II (HXKII) was regulated by IL-7 in a STAT5-independent manner. Our studies revealed that IL-7 promoted the activity of JNK (Jun N-terminal Kinase), and that JNK, in turn, drove the expression of JunD, a component of the Activating Protein 1 (AP-1) transcription factors. Gel shifts showed that the AP-1 complex induced by IL-7 contained JunD but not c-Fos or c-Jun. Inhibition of JNK/JunD blocked glucose uptake and HXKII gene expression, indicating that this pathway was responsible for promoting HXKII expression. Because others had shown that JunD was a negative regulator of cell growth, we performed a bioinformatics analysis to uncover possible JunD-regulated gene targets. Our search revealed that JunD could control the expression of proteins involved in signal transduction, cell survival and metabolism. One of these growth promoters was the oncogene, Pim-1. Pim-1 is an IL-7-induced protein that was inhibited when the activities of JNK or JunD were blocked, showing that in IL-7 dependent T-cells JunD can promote positive signals transduced through Pim-1. This was confirmed when the IL-7-induced proliferation of CD8 T-cells was impaired upon JunD inhibition. These results show that engagement of the IL-7 receptor drives a signal that is more complex than the JAK/STAT pathway, activating JNK and JunD to induce rapid growth stimulation through the expression of metabolic and signaling factors like HXKII and Pim-1

Occupational stress in the work of miners - a survey on coal mine workers

W artykule przedstawiono problematykę związaną ze stresem zawodowym wśród pracowników jednej z kopalń węgla kamiennego. Omówiono ogólne pojęcie stresu oraz stresu zawodowego, jak również stresorów, czyli bodźców, które wywołują reakcję organizmu. Przedstawiono także wyniki badań ankietowych odnośnie stresu zawodowego wśród pracowników analizowanej kopalni. Omówiono czynniki, które przyczyniają się do powstania stresu zawodowego, ich skutki oraz sposoby przeciwdziałania nadmiernej reakcji stresowej.This paper presents the problems associated with occupational stress among the employees of one of the coal mines. It describes the general concept of stress and occupational stress, as well as stressors or stimuli that elicit the body. We have presented the results of a survey regarding occupational stress among employees of the analyzed the coal mine. The factors which contribute to the formation of occupational stress, its effects and ways of counteracting excessive stress response have been discussed

Altersabhängige neuronale Plastizität im Gehirn von Drosophila melanogaster\textit {Drosophila melanogaster}

Die vorliegende Arbeit beschäftigt sich mit altersabhängigen Veränderungen der Morphologie im Gehirn bei $\textit {Drosophila melanogaster}$. Hierfür werden Volumenveränderungen der kompletten Antennalloben und der V-, DL3-, DA1-, VA1v- und DM1-Glomeruli von $\it {Drosophila}$ ermittelt. Die Volumenveränderungen werden in Abhängigkeit von äußeren und inneren Faktoren während der Alterung der Fliegen beobachtet. Hierbei wird der Einfluss von getrenntgeschlechtlicher Haltung, Langzeitstimulation und neuronaler Degeneration auf die Entwicklung der Antennalloben untersucht. Während der altersabhängigen Entwicklung der Antennalloben von $\it {Drosophila}$ lassen sich eine Entwicklungsphase, in der das Volumen zunimmt, und eine weitere Phase, in der es stagniert, unterscheiden. Ein volumenreduzierender Effekt auf die Antennalloben kann bei neurodegenerativen Mutanten nachgewiesen werden. Durch eine gezielte Langzeitstimulation kann das Volumen des DM1-Glomerulus reduziert werden

Poly(lactic acid)/hydroxyapatite melt spun composite fibers

W pracy zaproponowano metodę produkcji nano-kompozytowych włókien na bazie polilaktydu (PLA) i nano-hydroksyapatytu (n-HAp).In the present work, the method of production of nanocomposite fibers based on polylactide acid (PLA) and nano-hydroxyapatite (n-HAp) is proposed