Project description:Transcriptome analysis of prostate cancer patient derived organoid DU145 cell line upon knockdown of YAP, TAZ, or YAP/TAZ mediated by siRNAs
Project description:YAP knockdown in HUVEC elicits proliferation and cell cycle preogression defects. YAP deficient cells caused arrest in G1 and defects in S-phase entry. The microarray analysis was conducted to identify potential YAP targets that are involved in HUVEC cell cycle regulation mRNA samples were collected from siRNA treated HUVECs 30 hour after transfection. Four biological replicates were used for each condition: control (RISC-free) and knockdown (siYAP#1 and siYAP#2)
Project description:Transcriptome analysis of prostate cancer patient derived organoid MKS-PCa3 upon knockdown of FOSL1, YAP, TAZ, or YAP/TAZ mediated by siRNAs
Project description:We looked at the expression profiles of embyonic stem cells (ESCs) 48 hours after YAP siRNAs transfection, to knockdown YAP expression, or after pCAG-YAP transfection, to over-express YAP protein. Total RNA was isolated from three independent experiments and analyzed by RNA-seq.
Project description:Purpose: The clinical use of MEK inhibitors in uveal melanoma is limited by the rapid acquisition of resistance. The current study has used multi-omics approaches and drug screens to identify the pan-HDAC inhibitor panobinostat as an effective strategy to limit MEK inhibitor resistance. Experimental Design: Mass spectrometry-based proteomics and RNA-Seq was used to identify the signaling pathways involved in the escape of uveal melanoma cells from MEK inhibitor therapy. Mechanistic studies were performed to evaluate the escape pathways identified and the efficacy of the MEK-HDAC inhibitor combination was demonstrated in multiple in vivo xenograft models of uveal melanoma. Results: We identified a number of putative escape pathways that were upregulated following MEK inhibition including the PI3K/AKT pathway, ROR1/2 and IGF1R signaling. MEK inhibition was also associated with a widespread increase in GPCR expression, particularly the Endothelin B receptor and that this contributed to therapeutic escape through YAP signaling. A screen of 289 clinical grade compounds identified HDAC inhibitors as potential candidates that suppressed the adaptive YAP and AKT signaling that followed MEK inhibition. In vivo xenograft studies revealed the MEK-HDAC inhibitor combination to outperform either agent alone, leading to a long-term decrease of tumor growth and the suppression of adaptive PI3K/AKT and YAP signaling. Conclusions Together our studies have identified GPCR-mediated YAP activation and RTK-driven AKT signaling as key pathways involved in the escape of uveal melanoma cells from MEK inhibition. We further demonstrate that HDAC inhibition is a promising combination partner for MEK inhibitors in uveal melanoma.
Project description:Colorectal cancer progression involves dysregulated signaling pathways such as Hippo-YAP, but upstream regulators remain poorly defined. Here we demonstrate that oxysterol-binding protein-like 3 (OSBPL3) modulates Hippo-YAP signaling to drive tumor aggressiveness. Analysis of clinical specimens and experimental models showed that elevated OSBPL3 levels in colorectal cancer tissues correlate with shortened patient survival. Depleting OSBPL3 impaired cancer cell proliferation and invasion through cell cycle arrest, while its overexpression accelerated tumor growth. Mechanistic studies revealed that OSBPL3 binds 14-3-3 proteins to promote YAP1 nuclear translocation, activating downstream oncogenic pathways. Notably, tumors with high OSBPL3 expression exhibited resistance to MEK inhibitors, but this resistance was overcome by YAP1 suppression or combined YAP/MEK inhibition in patient-derived organoids. These results establish OSBPL3 as a critical Hippo-YAP pathway regulator and propose targeting OSBPL3-mediated signaling as a therapeutic strategy for colorectal cancers with Hippo pathway alterations
Project description:siRNA-mediated inhibition compared to untreated cells and cells transfected with nonsense siRNA. Loss of contact inhibition and anchorage-independent growth are hallmarks of cancer cells. In this context, frequent inactivation of the Hippo pathway and subsequent nuclear enrichment of the transcriptional coactivator yes-associated protein (YAP) uncouple cell proliferation and anti-apoptosis from contact inhibition, associated with uncontrolled tumor growth and tumor cell dissemination. However, general molecular mechanisms of tumor-supporting YAP activity remain unclear. In this study, we show that overexpression and nuclear accumulation of YAP in hepatocytes and hepatocellular carcinoma (HCC) cells leads to an induction of the Notch pathways through transcriptional activation of the Notch ligand jagged-1 (Jag-1). This induction of Jag-1 strictly depends on binding of YAP to TEAD4 and does not rely on WNT/β-catenin pathway activity. Co-activation of YAP, TEAD4, Jag-1, and the Notch target gene Hes-1 was significantly higher in HCC from patients with poor prognosis. High-level expression and nuclear accumulation of YAP correlates with Jag-1/Notch activation not only in human HCC tissues, but also in colon and pancreatic cancer tissues. Thus, our data demonstrate that YAP-driven co-activation of the Jag-1/Notch pathway in part facilitates oncogenic properties of the oncogene YAP not only in HCC but also in different gastrointestinal malignancies. Expression profiling of untreated HCC cell lines (control 1), cells transfected with scrambled/nonsense siRNA (control 2), and after siRNA-mediated YAP inhibition.
Project description:YAP knockdown in HUVEC elicits proliferation and cell cycle preogression defects. YAP deficient cells caused arrest in G1 and defects in S-phase entry. The microarray analysis was conducted to identify potential YAP targets that are involved in HUVEC cell cycle regulation
Project description:We analyzed by BS-seq the methylation pattern of CTR and YAP knockdown cells in undifferentiated (T0) embryonic stem cells (ESCs) vs cells differentiated toward neuroectodermal fate at day 4 of differentiation (T4). Two biological duplicates for each condition.