Project description:Ras and its downstream cascades transmit cellular signals, resulting in increased transcription of a large number of genes involved in cell growth and division. Research on long non-coding transcripts regulated by the Ras signaling cascade is still in its infancy. Long non-coding RNAs (lncRNAs) are operationally defined as transcripts that are larger than 200 nt that do not appear to have protein-coding potential. Using a custom-designed lncRNA microarray, we identified a novel lncRNA (oncogenic Ras-induced lncRNA 1, Orilnc1) whose expression is significantly induced by activation of Ras. Further molecular studies demonstrated that the expression of Orilnc1 is regulated by the Ras-Raf-MEK-ERK signaling cascade via the transcriptional factor AP1. Importantly, Orilnc1 is highly expressed in BRAF mutant cancers such as BRAF-driven melanoma. Inhibition of Orilnc1 expression by small RNA interference (siRNA) significantly blocked tumor cell proliferation and growth in vitro and in vivo. Finally, we observed that blocking Orilnc1 reduced expression levels of cell cycle related genes such as Cyclin E1 and induced G1/S arrest in tumor cells. Taken together, Orilnc1 may function as a novel non-protein mediator to respond the Ras/Raf activation and could serve as a potential therapeutic target for RAS or BRAF-driven cancers such as melanoma.
Project description:Muscle-invasive bladder cancer is closely associated with the susceptibility to metastasis and poor prognosis. In recent years, numerous studies have revealed that certain long non-coding RNAs (lncRNAs) may be involved in malignant progression of tumors. Here, we identified a lncRNA, telomerase RNA component (TERC), that is significantly upregulated in invasive bladder urothelial carcinoma tissues. We used in vitro and in vivo models to demonstrate its oncogenic effects. Mechanistically, we screened out the PPAR signaling pathway (RXRA, FABP3) regulated by TERC through proteomics and enrichment analysis.
Project description:To identify the the N-Ras-controlled genes in basal-like cells, we used shRNA to repress N-RAS in basal-like SUM102PT, SUM149PT and claudin-low SUM159PT cells. We seek the genes regulated only in basal-like, but not in claudin-low cells, to isolate the genes controlled by N-Ras in a breast cancer subtype-specific fashion. We also overexpressed oncogenic form N-Ras(G12D) in these cells in order to compare the genes regulated by wild-type and oncogenic N-Ras. The shRNA silencing and overexpression were conducted by lentiviral infection in the cells, with non-silencing shRNA-infected cells as the controls. The infected cells were then selected in antibiotics for about 5 days before total RNAs were harvested for microarray analysis. N-Ras was silenced by shRNA or oncogenic N-Ras (G12D) was overexpressed in basal-like SUM102PT, SUM149PT and claudin-low SUM159PT cells.