Project description:We report the results NGS based of miRNA profiling in human bronchial epithelial cells (16HBE) up on ER stress induction with Tunicamycin (2.5ug/ml) and ALLN (100uM)
Project description:Neurofibromatosis Type 1 (NF1) patients develop benign neurofibromas and malignant peripheral nerve sheath tumors (MPNST). These incurable peripheral nerve tumors result from loss of NF1 tumor suppressor gene function, causing hyperactive Ras signaling. Activated Ras controls numerous downstream effectors, but specific pathways mediating effects of hyperactive Ras in NF1 tumors are unknown. Cross-species transcriptome analyses of mouse and human neurofibromas and MPNSTs identified global negative feedback of genes that regulate Ras-Raf- MEK- extracellular signal-regulated protein kinase (ERK) signaling in both species. Nonetheless, activation of ERK was sustained in mouse and human neurofibromas and MPNST. PD0325901, a highly selective pharmacological inhibitor of MEK, was used to test whether sustained Ras-Raf-MEK-ERK signaling contributes to neurofibroma growth in the Nf1fl/fl;Dhh-cre mouse model or in NF1 patient MPNST cell xenografts. PD0325901 treatment reduced aberrantly proliferating cells in neurofibroma and MPNST, prolonged survival of mice implanted with human MPNST cells, and shrank neurofibromas in >80% of mice tested. PD0325901 also caused effects on tumor vasculature. Our data demonstrate that deregulated Ras/ERK signaling is critical for the growth of NF1 peripheral nerve tumors and provide strong rationale for testing MEK inhibitors in NF1 clinical trials.
Project description:The most common oncogenic mutations in multiple myeloma (MM) affect N- and K-RAS leading to constitutive activation of RAS-dependent signaling. Signal transduction via RAS, Raf and MAPK has been well described as a canonical pathway. In accordance with this assumption, we showed that the activity of the MEK/ERK module is strictly dependent on pan-Raf activity. However, inhibition of MEK/ERK has no or only minor effects on MM cell survival, whereas oncogenic Ras and pan-Raf critically contribute to survival of multiple myeloma cells. Therefore, we aimed to learn more about Raf-dependent but MEK-independent signaling effectors. We analyzed gene expression profiles in INA-6 cells after either pan-Raf inhibition with SB-590885 or MEK inhibition with PD-325901.
Project description:The role of FGF-MEK-ERK signalling pathway during embryonic heart development has not been fully elucidated. Here, we inhibited the pathway for 1 day using PD0325901, a MEK inhibitor, at the lateral plate mesoderm stage during cardiac differentiation of human embryonic stem cells. Cells were collected on day 2 (before PD0325901 administration), day 3 and day 8 to determine the effect of a transient FGF-MEK-ERK pathway modulation on the cardiac cell fate choice.
Project description:Hyperactive RAS signaling drives tumorigenesis in PAX 3/7::FOXO1 fusion-negative rhabdomyosarcoma (FN-RMS). Despite the frequency of these mutations, indirect RAS pathway-directed therapies have been ineffective for RAS-driven RMS. Farnesyltransferase (FTase) inhibitors (FTIs), such as tipifarnib, inhibit HRAS membrane localization and blunt HRAS effector signaling, leading to an antitumor effect in HRAS-mutant FN-RMS preclinical models. Response to FTase inhibition is limited by adaptive feedback reactivation of ERK signaling and upregulation of wild-type (WT) RAS. We found that the combination of HRAS suppression with FTI and MEK inhibition (MEKi) impaired ERK reactivation and reduced ERK transcriptional output in HRAS-mutant RMS models. Co-targeting FTase and MEK restrained tumor progression and induced terminal myogenic differentiation. These findings highlight an effective combinatorial strategy and support its preclinical translation for patients with HRAS-mutant RMS.
Project description:This study used microarray expression analysis to identify global changes in transcript alteration in response to MEK inhibition. Genes under ERK control were identified in a panel of V600E BRAF and RTK-activated tumor cells and xenografts, using short-term inhibition of ERK activity using the MEK inhibitor PD0325901 (Pfizer). Experiment Overall Design: Cell lines growing in culture (n=12) and murine xenografts (n=2) were treated with the MEK inhibitor PD0325901 or vehicle alone as control. Paired analysis of MEK inhibited to control samples was performed for two groups of tumor cells, V600E BRAF and RTK.
