MiR-362-3p functions as a tumor suppressor through targeting MCM5 in cervical adenocarcinoma
Authors: Wang, Dan; Wang, Hongyan; Li, Yichun; Li, Qian
Our previous study suggested that minichromosomemaintenance protein 5 (MCM5) overexpression was observed in cervical adenocarcinoma and closely associated with advanced clinical stage, more metastatic lymph nodes, present distant metastasis, low histological grade, and poor prognosis. Down-regulation of MCM5 inhibited cervical adenocarcinoma cell proliferation. The purpose of the present study is to search and confirm valuable microRNAs (miRNAs), which target MCM5 to modulate cervical adenocarcinoma cell proliferation. In our results, we found that levels of miR-362-3p expression were reduced in cervical adenocarcinoma tissues and cell lines. Moreover, 3'-UTR of MCM5 had binding site of miR-362-3p through analyzing Targetscan database and miRanda database, and there were an inverse association between miR-362-3p and MCM5 in cervical adenocarcinoma tissues. Furthermore, we verified miR-362-3p directly targeted to 3'-UTR of DCLK1 by luciferase reporter assay, and negatively regulated mRNA and protein expressions of MCM5 by qPCR and Western blot. Then, we conducted gain-of-function study and rescued-function study, and found that miR-362-3p served as a tumor suppressive miRNA to modulate cervical adenocarcinoma cell proliferation through regulating the functional target MCM5. Finally, we analyzed correlations between miR-362-3p expression and clinicopathological characteristics and observed that miR-362-3p low expression was associated with advanced clinical stage and poor prognosis. In conclusion, miR-362-3p is a tumor suppressive miRNA in cervical adenocarcinoma.
Dclk1 in tuft cells promotes inflammation-driven epithelial restitution and mitigates chronic colitis
CELL DEATH AND DIFFERENTIATION
Authors: Yi, Jun; Bergstrom, Kirk; Fu, Jianxin; Shan, Xindi; McDaniel, J. Michael; McGee, Samuel; Qu, Dongfeng; Houchen, Courtney W.; Liu, Xiaowei; Xia, Lijun
Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by defective intestinal barrier integrity toward the microbiota and epithelial damage. Double cortin-like kinase 1 (Dclk1), a marker of intestinal tuft cells, can regulate tissue regenerative responses, but its role in epithelial repair during bacterial-dependent chronic colitis is unclear. We addressed this question using our recently developed mouse model of spontaneous microbiota-dependent colitis induced by mucin-type O-glycan deficiency (DKO), which recapitulates most features of human UC. We generated DKO mice lacking intestinal epithelial Dclk1 (DKO;Dclk1(Delta IEC)) and analyzed colitis onset and severity using clinical and histologic indices, immune responses by qPCR and immunostaining, and epithelial responses using proliferation markers and organoid culture. We found 3-4-week-old DKO;Dclk1(Delta IEC) mice developed worsened spontaneous colitis characterized by reduced body weight, loose stool, severe colon thickening, epithelial lesions, and inflammatory cell infiltrates compared with DKO mice. The primary defect was an impaired epithelial proliferative response during inflammation. Dclk1 deficiency also reduced inflammation-induced proliferation and growth of colon organoids ex vivo. Mechanistically, Dclk1 expression was important for inflammation-induced Cox2 expression and prostaglandin E2 (PGE2) production in vivo, and PGE2 rescued proliferative defects in Dclk1-deficient colonic organoids. Although tuft cells were expanded in both DKO and DKO;Dclk1(Delta IEC) relative to WT mice, loss of Dclk1 was associated with reduced tuft cell activation (i.e., proliferation) during inflammation. Similar results were found in DKO vs. DKO;Dclk1(Delta IEC) mice at 3-6 months of age. Our results support that tuft cells, via Dclk1, are important responders to bacterial-induced colitis by enhancing epithelial repair responses, which in turn limits bacterial infiltration into the mucosa.