Department of Medicine, University of Chicago, Chicago IL, USA.
Departments of Pathology, University of Chicago, Chicago IL, USA.
Epigenetics. 2021 Dec;16(12):1317-1334. doi: 10.1080/15592294.2020.1863117. Epub 2020 Dec 28.
Because ADAM17 promotes colonic tumorigenesis, we investigated potential miRNAs regulating ADAM17; and examined effects of diet and tumorigenesis on these miRNAs. We also examined pre-miRNA processing and tumour suppressor roles of several of these miRNAs in experimental colon cancer. Using TargetScan, miR-145, miR-148a, and miR-152 were predicted to regulate ADAM17. miR-143 was also investigated as miR-143 and miR-145 are co-transcribed and associated with decreased tumour growth. HCT116 colon cancer cells (CCC) were co-transfected with predicted ADAM17-regulating miRNAs and luciferase reporters controlled by ADAM17-3'UTR. Separately, pre-miR-143 processing by colonic cells was measured. miRNAs were quantified by RT-PCR. Tumours were induced with AOM/DSS in WT and transgenic mice (Tg) expressing pre-miR-143/miR-145 under villin promoter. HCT116 transfection with miR-145, -148a or -152, but not scrambled miRNA inhibited ADAM17 expression and luciferase activity. The latter was suppressed by mutations in ADAM17-3'UTR. Lysates from colonocytes, but not CCC, processed pre-miR-143 and mixing experiments suggested CCC lacked a competency factor. Colonic miR-143, miR-145, miR-148a, and miR-152 were downregulated in tumours and more moderately by feeding mice a Western diet. Tg mice were resistant to DSS colitis and had significantly lower cancer incidence and tumour multiplicity. Tg expression blocked up-regulation of putative targets of miR-143 and miR-145, including ADAM17, K-Ras, XPO5, and SET. miR-145, miR-148a, and miR-152 directly suppress colonocyte ADAM17 and are down-regulated in colon cancer. This is the first direct demonstration of tumour suppressor roles for miR-143 and miR-145 in an model of colonic tumorigenesis.
由于 ADAM17 促进结直肠肿瘤发生，我们研究了潜在的 miRNA 来调节 ADAM17；并检查了饮食和肿瘤发生对这些 miRNA 的影响。我们还研究了这些 miRNA 中的几种在实验性结肠癌中的前 miRNA 加工和肿瘤抑制作用。使用 TargetScan，预测 miR-145、miR-148a 和 miR-152 调节 ADAM17。还研究了 miR-143，因为 miR-143 和 miR-145 是共转录的，并与肿瘤生长减少有关。将 HCT116 结肠癌细胞（CCC）与预测的 ADAM17 调节 miRNA 和 ADAM17-3'UTR 控制的荧光素酶报告基因共转染。分别测量结肠细胞中前 miR-143 的加工。通过 RT-PCR 定量 miRNA。在 WT 和表达 villin 启动子的 pre-miR-143/miR-145 的转基因小鼠（Tg）中用 AOM/DSS 诱导肿瘤。用 miR-145、miR-148a 或 miR-152 转染 HCT116，但不是用 scrambled miRNA 抑制 ADAM17 表达和荧光素酶活性。后者被 ADAM17-3'UTR 中的突变抑制。来自结肠细胞的裂解物，但不是 CCC，加工前 miR-143，混合实验表明 CCC 缺乏一种必需因子。结直肠 miR-143、miR-145、miR-148a 和 miR-152 在肿瘤中下调，在 Western 饮食喂养的小鼠中下调更为适度。Tg 小鼠对 DSS 结肠炎具有抗性，并且癌症发生率和肿瘤多发性显著降低。Tg 表达阻断了 miR-143 和 miR-145 的潜在靶标，包括 ADAM17、K-Ras、XPO5 和 SET 的上调。miR-145、miR-148a 和 miR-152 直接抑制结肠细胞中的 ADAM17，并且在结肠癌中下调。这是首次直接证明 miR-143 和 miR-145 在结直肠肿瘤发生的 模型中具有肿瘤抑制作用。
