Project description:The 90 kDa ribosomal S6 kinases (RSKs) are serine threonine kinases comprising four isoforms. The isoforms can have overlapping functions in regulation of migration, invasion, proliferation, survival, and transcription in various cancer types. We delineate RSK isoform-specific transcriptional gene regulation by comparing transcription programs in RSK1 and RSK2 knockout cells using microarray analysis.
Project description:The RSK2 gene is responsible for Coffin-Lowry syndrome, an X-linked monogenic disease associating severe learning deficit andassociated to typical facial and digital abnormalities and skeletal changes. Craniofacial and dental anomalies encountered in this rare disease have been poorly characterized. In this study we explore, through X-Ray microtomographic analysis, the variable craniofacial dysmorphism and dental anomalies present in Rsk2 knockout mice, an animal model of Coffin-Lowry syndrome, as well as in triple Rsk1,2,3 knockout mutants. We report in these mutants the occurrence of a surpernumerary tooth mesial to the first molar. This highly penetrant phenotype is considered as a remnant of evolutionary lost teeth. This possibly leads to the significant reduction of the maxillary diastema. Abnormalities of molar shape were almost restricted to the mesial part of both upper and lower first molars (M1). We also report an expression analysis of the four Rsk genes (Rsk1, 2, 3 and 4) at various stages of odontogenesis in wild-type (WT) mice. Rsk2 was mainly expressed in the mesenchymal, neural crest derived compartment, correlating with proliferative areas of the developing teeth and consistent with a biological function of RSK2 in cell cycle control and cell growth, which when invalidated could be responsible for the dental phenotype. In an attempt to unravel the molecular pathways involved in the genesis of these dental defects, we performed a comparative transcriptomic (DNA microarray) analysis of mandibular wild-type versus Rsk2-/Y molars, and further demonstrated a misregulation of selected genes, using a Rsk2 shRNA knock-down strategy in molar tooth germs cultured in vitro.
Project description:The p90 ribosomal S6 kinase (RSK) family, a downstream target of Ras/extracellular signal-regulated kinase (ERK) signaling, can mediate cross-talk with the mammalian target of rapamycin complex 1 (mTORC1) pathway. As RSK connects two oncogenic pathways in gliomas, we investigated the protein levels of the RSK isoforms RSK1-4 in non-tumoral brain (NB) and grade I-IV gliomas. RSK4 expression was not detected in any brain tissues, whereas RSK3 expression was very low, with GBMs demonstrating the lowest RSK3 protein levels. When compared to NB or low-grade gliomas (LGG), a group of glioblastomas (RSK1hi) that excluded long-survivor cases expressed higher levels of RSK1. No difference was observed in RSK2 median-expression levels among NB and gliomas; however, high levels of RSK2 in glioblastomas (GBM) were associated with worse survival. RSK1hi and, to a lesser extent, RSK2hi GBMs, showed higher levels of phosphorylated RSK, which indicates RSK activation. Transcriptome analysis indicated that most RSK1hi GBMs belonged to the mesenchymal subtype, and RSK1 expression strongly correlated with gene expression signature of immune infiltrates, in particular of activated-natural killer cells and M2 macrophages. In an independent cohort, we confirmed that RSK1hi GBMs exclude long-survivors, and RSK1 expression was associated with high protein levels of the mesenchymal subtype marker LAPTM5, as well as with high expression of CD68, which indicated the presence of infiltrating immune cells. An RSK1 signature was obtained based on differentially expressed mRNAs and validated in public glioma datasets. Enrichment of RSK1 signature followed glioma progression, recapitulating RSK1 protein expression, and was associated with worse survival not only in GBM but also in LGG. In conclusion, both RSK1 and RSK2 associate with glioma malignity, but displaying isoform-specific peculiarities. The progression-dependent expression and association with immune infiltration, suggests RSK1 as a potential progression marker and therapeutic target for gliomas.
Project description:RSK2 is a serine/threonine kinase downstream signaling mediator in the RAS/ERK signaling pathway and may be a therapeutic target in mantle cell lymphoma (MCL). RSK2-Ser227 in the N-terminal kinase domain (NTKD) of RSK2 was found to be ubiquitously active in five MCL-derived cell lines and in tumor tissues derived from five MCL patients. BI-D1870, an inhibitor specific to RSK2-NTKD, caused RSK2-Ser227 dephosphorylation, and thereby, induced dose-dependent growth inhibition via G2/M cell cycle blockade and apoptosis. Comparative gene expression profiling of the MCL-derived cell lines showed that inhibition of RSK2-Ser227 by BI-D1870 caused downregulation of oncogenes, such c-MYC and MYB; anti-apoptosis genes, such as BCL2 and BCL2L1; genes for B cell development, including IKZF1, IKZF3 and PAX5; and genes constituting the B cell receptor signaling pathway, such as CD19, CD79B and BLNK. These findings show that targeting of RSK2-Ser227 enables concomitant blockade of pathways that are critically important in B cell tumorigenesis.
Project description:We showed that DBTRG is more invasive than U251 cell lines by novel brain-stiffness-mimicking matrix gel invasion platform and transwell invasion assay. To understand the molecular mechanisms of DBTRG being more invasive than U251, we performed transcriptomic sequencing analysis of DBTRG and U251 cell lines.
Project description:To investigate the function of COL8A1 in GSCs progression, we established U251-COL8A1 cell lines with COL8A1 overexpressed. Then we performed gene expression profiling analysis using data obtained from RNA-seq of 2 cells (U251NC and U251-COL8A1)
Project description:Assess gene expression patterns upon HOXA9 ectopic expression in U87MG GBM cell line and hTERT/E6/E7 immortalized human astrocytes, and HOXA9 silencing in U251 and GBML18 GBM cell lines. U87MG and hTERT/E6/E7 were retrovirally-infected with an MSCV control vector (MSCV-Control) or with a construct containing the coding region of HOXA9 (MSCV-HOXA9), resulting in U87MG-Control, U87MG-HOXA9, hTERT/E6/E7-Control and hTERT/E6/E7-HOXA9 cell lines. GBML18 and U251 cells were transfected with HOXA9 gene-specific shRNA sequences (shHOXA9) or a non-efective shRNA (shControl) in pGFP-V-RS plasmid, resulting in U251-shControl, U251-shHOXA9, GBML18-shControl and GBML18-shHOXA9 cell lines. Four experimental replicates for HOXA9 overexpression cell lines, and three for HOXA9 silencing cell lines were performed.
Project description:Hydrogen deuterium exchange mass spectrometry data of the ERK2-RSK2 and ERK2-RSK2-ORF45 complexes. The noncatalytic viral protein ORF45 reconfigures ERK-RSK signaling in cells. This dataset identifies the ORF45-RSK2 interface.