Project description:Transcriptional profiling of squamous cell carcinoma of oral tongue, comparing p53 NS+ and p53 NS- tumors. Goal was to determine differentially expressed genes between them based on global gene expression.
Project description:Expression of virulence genes in pathogenic E. coli is controlled in part by the transcription silencer H-NS and its paralogs (e.g., StpA), which sequester DNA in multi-kb nucleoprotein filaments to inhibit transcription initiation, elongation, or both. Some activators counter-silence initiation by displacing H-NS from promoters. How H-NS inhibition of elongation is overcome is not understood. In uropathogenic E. coli (UPEC), elongation regulator RfaH aids expression of some H-NS-silenced pathogenicity operons (e.g., hlyCABD encoding hemolysin). RfaH associates with elongation complexes (ECs) via direct contacts to a transiently exposed, nontemplate DNA-strand sequence called ops (operon polarity suppressor). RfaH–ops interactions establish long-lived RfaH–EC contacts that allow RfaH to recruit ribosomes to the nascent mRNA and to suppress transcriptional pausing and termination. Using ChIP-seq, we mapped the genome-scale distributions of RfaH, H-NS, StpA, RNA polymerase (RNAP), and σ70 in the UPEC strain CFT073. We identify 8 RfaH-activated operons, all of which were bound by H-NS and StpA. Four are new additions to the RfaH regulon. Deletion of RfaH caused premature termination whereas deletion of H-NS and StpA allowed elongation without RfaH. Thus, RfaH is an elongation counter-silencer of H-NS. Consistent with elongation counter-silencing, deletion of StpA alone decreased the effect of RfaH. StpA increases DNA bridging, which inhibits transcript elongation via topological constraints on RNAP. Residual RfaH effect when both H-NS and StpA were deleted was attributable to targeting of RfaH-regulated operons by a minor H-NS paralog, Hfp. These operons have evolved higher levels of H-NS–binding features, explaining minor-paralog targeting.
Project description:To study the effect of the ACVR1 G328V mutation in tumor neurospheres with a background of NRASV12 overexpression and p53 knockdown. The goal of this study was to identify differentially expressed genes between mACVR1 NS v wt-ACVR1 NS.
Project description:Transcriptional profiling of Esophageal Squamous Cell Carcinoma (ESCC) tumors comparing samples harbouring nuclear-stabilized p53 (NS+) versus unstable p53 (NS-) protein, determined through immunohistochemistry (IHC) staining of the tumor sections. The goal was to identify the genes that were differentially regulated between NS+ and NS- ESCC samples.
Project description:N-lactoyl-phenylalanine (Lac-Phe) is a lactate-derived metabolite that suppresses food intake and body weight. Little is known about the mechanisms that mediate Lac-Phe transport across cell membranes. Here we identify SLC17A1 and SLC17A3, two kidney-restricted plasma membrane-localized solute carriers, as physiologic urine Lac-Phe transporters. In cell culture, SLC17A1/3 exhibit high Lac-Phe efflux activity. In humans, levels of Lac-Phe in urine exhibit a strong genetic association with the SLC17A1-4 locus. Urine Lac-Phe levels are also increased following a Wingate sprint test. In mice, genetic ablation of either SLC17A1 or SLC17A3 reduces urine Lac-Phe levels. Despite these differences, both knockout strains have normal blood Lac-Phe and body weights, demonstrating SLC17-dependent de-coupling of urine and plasma Lac-Phe pools. Together, these data establish SLC17A1/3 family members as the physiologic urine transporters for Lac-Phe and uncover a biochemical pathway for the renal excretion of this signaling metabolite. Our data do not exclude the involvement of other transporters in mediating Lac-Phe transport.