Browsing by Subject "colon cancer"
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Item Open Access A long non-coding RNA targets microRNA miR-34a to regulate colon cancer stem cell asymmetric division.(Elife, 2016-04-14) Wang, Lihua; Bu, Pengcheng; Ai, Yiwei; Srinivasan, Tara; Chen, Huanhuan Joyce; Xiang, Kun; Lipkin, Steven M; Shen, XilingThe roles of long non-coding RNAs (lncRNAs) in regulating cancer and stem cells are being increasingly appreciated. Its diverse mechanisms provide the regulatory network with a bigger repertoire to increase complexity. Here we report a novel LncRNA, Lnc34a, that is enriched in colon cancer stem cells (CCSCs) and initiates asymmetric division by directly targeting the microRNA miR-34a to cause its spatial imbalance. Lnc34a recruits Dnmt3a via PHB2 and HDAC1 to methylate and deacetylate the miR-34a promoter simultaneously, hence epigenetically silencing miR-34a expression independent of its upstream regulator, p53. Lnc34a levels affect CCSC self-renewal and colorectal cancer (CRC) growth in xenograft models. Lnc34a is upregulated in late-stage CRCs, contributing to epigenetic miR-34a silencing and CRC proliferation. The fact that lncRNA targets microRNA highlights the regulatory complexity of non-coding RNAs (ncRNAs), which occupy the bulk of the genome.Item Open Access Inconsistencies in Colonic Tattooing Practice: Differences in Reported and Actual Practices at a Tertiary Medical Center.(Southern medical journal, 2019-04) Spaete, Joshua P; Zheng, Jiayin; Chow, Shein-Chung; Burbridge, Rebecca A; Garman, Katherine SOBJECTIVES:Accurate localization of a colonic lesion is crucial to successful resection. Although colonic tattooing is a widely accepted technique to mark lesions for future identification surgery or repeat colonoscopy, no consensus guidelines exist. The objective of this study was to determine whether the current tattooing practice at a tertiary medical center differs from recommendations in the literature and self-reported provider practice. METHODS:The study consisted of an observational retrospective chart review of patients who received colonic tattoos, as well as a provider survey of reported tattooing practices at a tertiary academic medical center. A total of 747 patients older than 18 years of age who underwent colonoscopy with tattoo were included. Forty-four gastroenterologists performing endoscopy were surveyed on tattooing techniques. RESULTS:In the majority of cases, neither the number of tattoos, location of the tattoo nor the distance from the lesion was specified within the report. Following the index procedure, a tattoo was detected in 75% of surgical resections and 73% of endoscopies. At the time of surgery, however, the tattoo and/or the lesion was detected approximately 94% of the time. Twenty-five endoscopists (56.8%) completed the survey. Differences were seen the between the chart review and reported practice. Most providers report placing ≥2 marks (87.2%); however, chart review revealed that only 56.2 % were tattooed with ≥2 marks. CONCLUSIONS:Variation exists between the reported tattooing practice and actual practice. Despite this, most tattoos are identified at the time of surgery or repeat endoscopy. Further research is needed to determine whether a standardized approach to tattooing and reporting could improve localization at repeat endoscopy.