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1.
FASEB J ; 33(2): 2314-2326, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30252536

RESUMO

This study investigates the mechanism and consequences of microRNA-22 ( miR-22) induction. Our data revealed for the first time that retinoic acid (RA) and histone deacetylase (HDAC) inhibitors, including short-chain fatty acids and suberanilohydroxamic acid (SAHA), could individually or in combination induce miR-22. This induction was mediated via RA receptor ß (RARß) binding to a direct repeat 5 (DR5) motif. In addition, we uncovered HDAC1 as a novel miR-22 target. In an miR-22-dependent manner, HDAC inhibitors and RA reduced HDAC1, HDAC4, and sirtuin 1 (SIRT1), which were involved in chromatin remodeling of the RARß and nerve growth factor IB ( NUR77). Thus, HDAC inhibitors and RA-induced miR-22 resulted in simultaneous induction of cytoplasmic RARß and NUR77, leading to apoptosis of colon cancer cells. In mice, miR-22 and its inducers inhibited the growth of xenograft colon cancer. Moreover, tumor size reduction was accompanied by elevated miR-22, NUR77, and RARß and by reduced HDACs. In human colon polyps and adenocarcinomas, miR-22 and RARß were consistently reduced, which was associated with elevated HDAC1, HDAC4, and SIRT1 in colon adenocarcinomas. Results from this study revealed a novel anticancer mechanism of RARß via miR-22 induction to epigenetically regulate itself and NUR77, providing a promising cancer treatment modality using miR-22 and its inducers.-Hu, Y., French, S. W., Chau, T., Liu, H.-X., Sheng, L., Wei, F., Stondell, J., Garcia, J. C., Du, Y., Bowlus, C. L., Wan, Y.-J. Y. RARß acts as both an upstream regulator and downstream effector of miR-22, which epigenetically regulates NUR77 to induce apoptosis of colon cancer cells.


Assuntos
Adenocarcinoma/patologia , Apoptose/genética , Neoplasias do Colo/patologia , Epigênese Genética/genética , MicroRNAs/genética , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Receptores do Ácido Retinoico/metabolismo , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Xenoenxertos , Histona Desacetilase 1/genética , Inibidores de Histona Desacetilases/farmacologia , Humanos , Camundongos , Receptores do Ácido Retinoico/genética , Transdução de Sinais , Tretinoína/metabolismo
2.
Endosc Int Open ; 7(12): E1585-E1591, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31788539

RESUMO

Objectives and study aim Colonoscopy prevents colorectal cancer by removing adenomatous polyps, but missed adenomas lead to interval cancers. Different devices have been used to increase adenoma detection rates (ADR). Two such devices of interest are the transparent cap (Olympus) and Endocuff (ARC Medical). Our study aimed to compare differences in ADR between Endocuff-assisted colonoscopy (EAC), cap-assisted colonoscopy (CAC) and standard colonoscopy (SC). Patients and methods A sample size of 126 subjects was calculated to determine an effect size of 30 %. Patients undergoing screening or surveillance colonoscopy between March 2016 and January 2017 were randomized to SC, CAC or EAC groups. Three experienced endoscopists performed all colonoscopies. Patient demographics, procedure indication, Boston Bowel Prep Score (BBPS), withdrawal time, polyp size, location, histopathology, were analyzed. Results There was no difference in ADR (52 %, 40 % and 54 %) in the SC, CAC and EAC groups respectively ( P  = 0.4). Similar findings were also observed for proximal ADR (45 %, 35 %, and 50 %, P  = 0.4) and SSA detection rate (16 %, 14 %, and 23 %, P  = 0.5). EAC detected higher mean ADR per colonoscopy compared to CAC (1.70 vs 0.76, P  = 0.01). However, there was no significant difference in mean ADR per positive colonoscopy (2.08, 1.63, and 2.59, P  = 0.21). Conclusion In a randomized controlled trial comparing AC to CAC and SC, neither device conferred additional benefits in ADR among high detectors. When comparing each device, EAC may be better than CAC at detecting more total adenomas.

3.
ACG Case Rep J ; 4: e19, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28184376

RESUMO

Autoimmune enteropathy (AIE) is rare but damaging. The lack of consistent objective findings makes diagnosis a challenge. A 45-year-old male developed noninfectious diarrhea with significant weight loss and electrolyte abnormalities. Computed tomography delineated enteritis. Colonoscopy and esophagogastroduodenoscopy showed villous atrophy, chronic inflammation, and ulceration of the terminal ileum and cecum. Pathology showed cryptitis with apoptosis and abscesses throughout the small and large bowel and absent goblet cells. Steroids rapidly improved symptoms. Anti-enterocyte antibody serologies were negative. Management can be challenging, and, in this case, the patient initially improved with budesonide and infliximab but required alternative anti-tumor necrosis factor therapy after relapsing. This is an unusual presentation of seronegative AIE, which should be considered in cases of persistent severe diarrhea.

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