@article{AnelliOrdasKneitzetal.2018, author = {Anelli, Viviana and Ordas, Anita and Kneitz, Susanne and Sagredo, Leonel Munoz and Gourain, Victor and Schartl, Manfred and Meijer, Annemarie H. and Mione, Marina}, title = {Ras-Induced miR-146a and 193a Target Jmjd6 to Regulate Melanoma Progression}, series = {Frontiers in Genetics}, volume = {9}, journal = {Frontiers in Genetics}, number = {675}, issn = {1664-8021}, doi = {10.3389/fgene.2018.00675}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196963}, year = {2018}, abstract = {Ras genes are among the most commonly mutated genes in human cancer; yet our understanding of their oncogenic activity at the molecular mechanistic level is incomplete. To identify downstream events that mediate ras-induced cellular transformation in vivo, we analyzed global microRNA expression in three different models of Ras-induction and tumor formation in zebrafish. Six microRNAs were found increased in Ras-induced melanoma, glioma and in an inducible model of ubiquitous Ras expression. The upregulation of the microRNAs depended on the activation of the ERK and AKT pathways and to a lesser extent, on mTOR signaling. Two Ras-induced microRNAs (miR-146a and 193a) target Jmjd6, inducing downregulation of its mRNA and protein levels at the onset of Ras expression during melanoma development. However, at later stages of melanoma progression, jmjd6 levels were found elevated. The dynamic of Jmjd6 levels during progression of melanoma in the zebrafish model suggests that upregulation of the microRNAs targeting Jmjd6 may be part of an anti-cancer response. Indeed, triple transgenic fish engineered to express a microRNA-resistant Jmjd6 from the onset of melanoma have increased tumor burden, higher infiltration of leukocytes and shorter melanoma-free survival. Increased JMJD6 expression is found in several human cancers, including melanoma, suggesting that the up-regulation of Jmjd6 is a critical event in tumor progression. The following link has been created to allow review of record GSE37015: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?token=jjcrbiuicyyqgpc\&acc=GSE37015.}, language = {en} } @article{GrimmHufnagelWobseretal.2018, author = {Grimm, Johannes and Hufnagel, Anita and Wobser, Marion and Borst, Andreas and Haferkamp, Sebastian and Houben, Roland and Meierjohann, Svenja}, title = {BRAF inhibition causes resilience of melanoma cell lines by inducing the secretion of FGF1}, series = {Oncogenesis}, volume = {7}, journal = {Oncogenesis}, number = {71}, doi = {10.1038/s41389-018-0082-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-177261}, year = {2018}, abstract = {Approximately half of all melanoma patients harbour activating mutations in the serine/threonine kinase BRAF. This is the basis for one of the main treatment strategies for this tumor type, the targeted therapy with BRAF and MEK inhibitors. While the initial responsiveness to these drugs is high, resistance develops after several months, frequently at sites of the previously responding tumor. This indicates that tumor response is incomplete and that a certain tumor fraction survives even in drug-sensitive patients, e.g., in a therapy-induced senescence-like state. Here, we show in several melanoma cell lines that BRAF inhibition induces a secretome with stimulating effect on fibroblasts and naive melanoma cells. Several senescence-associated factors were found to be transcribed and secreted in response to BRAF or MEK inhibition, among them members of the fibroblast growth factor family. We identified the growth factor FGF1 as mediator of resilience towards BRAF inhibition, which limits the pro-apoptotic effects of the drug and activates fibroblasts to secrete HGF. FGF1 regulation was mediated by the PI3K pathway and by FRA1, a direct target gene of the MAPK pathway. When FGFR inhibitors were applied in parallel to BRAF inhibitors, resilience was broken, thus providing a rationale for combined therapeutical application.}, language = {en} }