Project description:Background: The expression of MDM4, a well-known p53-inhibitor, is positively associated with chemotherapy response and overall survival in epithelial ovarian cancer (EOC). The basis of this association remains elusive. Since the occurrence of metastasis is one of the factors responsible for the high death rate of this cancer, we analyzed MDM4 involvement in EOC metastatic process. Methods: In vivo and in vitro models, based on 2D and 3D assays, were employed to assess the activity of MDM4 in ovarian cancer progression. A 3D-bioprinting co-culture system was ad hoc developed for this study. Proteomic analysis was conducted on 3D multicellular tumour spheroids to assess pathways triggered by MDM4 overexpression. Results: In mouse models, increased MDM4 reduced intraperitoneal dissemination of human and murine EOC cells, independently of p53 and in a cell-autonomous way. Consistently, high MDM4 correlates with increased overall survival probability in large public data sets. 2D and 3D assays indicated that MDM4 impairs the early steps of the metastatic process. The 3D-bioprinting co-culture system showed reduced dissemination and intravasation into vessel-like structures of MDM4-expressing cells. Proteomic analysis of EOC spheroids revealed that MDM4 reduces protein synthesis and decreases mTOR signaling. Accordingly, MDM4 did not further inhibit EOC cell migration when its activity towards mTOR is blocked genetically or pharmacologically. Conversely, increased MDM4 reduced the efficacy of mTOR inhibitors in constraining EOC cell migration. Conclusions: Overall, these data clarify the antagonism of MDM4 towards EOC progression and suggest the usefulness of MDM4 assessment for tailored application of mTOR targeted therapy.
Project description:Transcriptional profiling of human colon cancer SW480 cells comparing control untreated SW480 cells with cells stably transfected with LRP16 treated with or without etoposide (50 μM) for the indicated periods (0,1hour, 3hours).An exploratory microarray analysis was performed with mRNA extracted from clutured SW480 cells transfected with LRP16 or control plasmid that were treated with or without etoposide. Total RNA of colon cancer cells stably transfected with vector control and LRP16 treated with or without etoposide (50 μM) for the indicated periods was isolated and purified using RNeasy Kit (Qiagen, Hilden, Germany). Integrity of RNA was assessed by using an Agilent BioAnalyser 2100 (Agilent Technologies).
Project description:Here we describe broad anti-proliferative activity of potent, selective, reversible inhibitors of protein arginine methyltransferase5 (PRMT5) including GSK3326595 in human cancer cell lines representing both hematologic and solid malignancies. Interestingly, PRMT5 inhibition activated the p53 pathway via the induction of alternative splicing of MDM4. The MDM4 isoforms witch and subsequent p53 activation are critical determinants of the response to PRMT5 inhibition suggesting that the integrity of the p53-MDM4 regulatory axis defines a subset of patients that could benefit from treatment with GSK3326595.
Project description:Malignant rhabdoid tumors (MRT) are highly aggressive pediatric cancers that respond poorly to current therapies. We screened several MRT cell lines each with large-scale RNAi, CRISPR-Cas9, and small-molecule libraries to identify potential drug targets specific for these cancers. We discovered MDM2 and MDM4, the canonical negative regulators of p53, as significant vulnerabilities. Using two compounds currently in clinical development, idasanutlin and ATSP-7041, we show that MRT cells are more sensitive than other p53 wild-type cancer cell lines to MDM2 and dual MDM2/4 inhibition in vitro. These compounds cause significant upregulation of the p53 pathway in MRT cells, and sensitivity is ablated by CRISPR-Cas9-mediated inactivation of TP53. We show that loss of SMARCB1, a subunit of the SWI/SNF (BAF) complex mutated in nearly all MRT, sensitizes cells to MDM2 and MDM2/4 inhibition by enhancing p53-mediated apoptosis. Both MDM2 and MDM2/4 inhibition slowed MRT xenograft growth in vivo, with a five-day idasanutlin pulse causing marked regression of all xenografts including durable complete responses in 50% of mice. Together, these studies identify a genetic connection between mutations in the SWI/SNF chromatin-remodeling complex and the tumor suppressor gene p53, and provide preclinical evidence to support the targeting of MDM2 and MDM4 in this often-fatal pediatric cancer.
Project description:The WWOX gene is a tumor suppressor probably involved in regulation of cell cycle and apoptosis and downregulated in variety of cancer types.However, its role in colon cancerogenesis is unknown. The aim of this study was to characterize how WWOX may be involved in colon cancerogenesis or cancer progression, how it influences the basic cancer cell features and modifies cell expression profile.Our observations suggest that in HT29 colon cancer cell line increased expression of WWOX may result in transition of cancer cells into more normal- like colon epithelium phenotype, on the other hand in SW480 WWOX revealed the well-known tumour suppressor properties. However, as the colon cancer is very heterogeneous disease, obtained discrepancies may reflect the known differences between cell lines and cancerogenesis pathway, which they undergone. SW480 colon cancer cells were stably transfected with WWOX cDNA. SW480 cells transfected with an empty vector served as a control. Total mRNA was isolated to look for gene-expression differences induced by the WWOX overexpression.
Project description:The role of SPROUTY2 (SPRY2) in human colon cancer is controversial. Our data support a tumorigenic action of SPRY2. We use microarrays to identify SPRY2 target genes in human SW480 ADH colon carcinoma cell line. RNA was obtained from SW480 ADH cells, Mock transfected or transfected with WT or two differents SPRY2 genes mutants. Hybridization was performed on Affymetrix microarrays. We performed three independent experiments. Each experiment was conducted in triplicate.
Project description:We employed whole genome expression profiling to identify differential gene expression in the colorectal cancer (CRC) cell line SW480 (ATCC - CCL-228), dependent on the expression level of MACC1 (Metastasis Associated in Colon Cancer 1). SW480 cells with endogenously low expression levels of MACC1 were transfected either with CMV-promoter driven MACC1-cDNA or the empty vector, and selected for stable expression.
Project description:To investigate the cooperative function ALDH1B1 in the regulation of colon cancer cells, we established SW480 cell lines in which ALDH1B1 has been knocked down by shRNA and the control SCR SW480 cells.
Project description:Whole transcriptome expression levels of SW480 colon adenocarcinoma cells transfected with LINC00152 Stealth siRNAs or Stealth Negative Control Medium GC siRNAs, analyzed by HTA 2.0 microarrays
Project description:Epicardial cells are progenitors giving rise to the majority of cardiac fibroblasts, coronary smooth muscle cells, and pericytes during cardiac development, and critically modulating heart morphogenesis and coronary development. An integral phase of epicardial cell fate transition is epithelial-to-mesenchymal transition (EMT), which confers motility and facilitates cell fate transition. We identify a pathway involving protein arginine methyltransferase 1 (PRMT1) and its downstream p53 signaling that drives epicardial EMT and invasion. We show that PRMT1 determines the half-life of p53 through regulating alternative splicing of Mdm4, which is a key controller of p53 degradation. Loss of PRMT1 promotes the expression of Mdm4 short form, which inhibits p53 degradation. Accumulation of p53 subsequently enhances Slug degradation and blocks epicardial EMT. We further demonstrated that the PRMT1-Mdm4-p53 pathway drives epicardial cell fate transition into cardiac fibroblasts, coronary smooth muscle cells and pericytes in vivo, and modulates ventricular morphogenesis and coronary vessel formation. Together, our results establish critical functions of the PRMT1-Mdm4-p53 pathway in epicardial EMT, invasion and cell fate transition.