The Second Hospital of Hebei Medical University, No. 215 Heping West Road, Shijiazhuang, 050000, Hebei, China.
The Second Hospital of Hebei Medical University, No. 215 Heping West Road, Shijiazhuang, 050000, Hebei, China.
Arch Biochem Biophys. 2020 May 30;685:108353. doi: 10.1016/j.abb.2020.108353. Epub 2020 Mar 29.
Despite of previous report regarding the aberrant overexpression of hsa_circ_0011290 in thyroid cancer, the regulatory mechanism and mechanistic involvements of which were still elusive currently in papillary thyroid cancer (PTC). Here we set out to characterize expression status and functional contributions of hsa_circ_0011290 in this disease especially through mode-of-action of sponging RNA.
Relative expression of hsa_circ_0011290, microRNA (miR)-1252 and FSTL1 was quantified by real-time polymerase chain reaction. Glucose metabolism was determined by examination of glucose uptake, lactate production and ATP contents. The regulatory effects of miR-1252 on both hsa_circ_0011290 and Follistatin Like 1 (FSTL1) were interrogated by luciferase reporter assay. Direct binding between miR-1252 with hsa_circ_0011290 and FSTL1 transcripts were analyzed by RNA pulldown assay. Protein levels of FSTL1 was examined by Western blots.
Aberrant over-expression of hsa_circ_0011290 was associated with advanced stage and unfavorable prognosis of PTC. Knockdown of hsa_circ_0011290 greatly inhibited cell viability, proliferation and stimulated cell apoptosis in PTC cells. Meanwhile, glucose metabolism was significantly switched with decreased glucose uptake and lactate production, and increased ATP contents. We identified miR-1252 as target miR of hsa_circ_0011290, and miR-1252 evidently inhibited expressions of both luciferase reporter and endogenous hsa_circ_0011290, and miR-1252 was negatively regulated by hsa_circ_0011290 vice versa. We further suggested that FSTL1 as direct target of miR-1252, and provided direct evidences in support of binding between miR-1252 with both hsa_circ_0011290 and FSTL1. Through sponging miR-1252, hsa_circ_0011290 was capable of positively modulate FSTL1 expression. Notably, inhibition of miR-1252 completely reversed phenotypic effects of hsa_circ_0011290 knockdown including cell viability, proliferation, apoptosis and glucose metabolisms.
Our study uncovered the oncogenic contributions of hsa_circ_0011290-miR-1252-FSTL1 in PTCs.
尽管先前有报道称 hsa_circ_0011290 在甲状腺癌中异常过表达，但目前在甲状腺乳头状癌（PTC）中，其调控机制和作用机制仍不清楚。在这里，我们着手研究 hsa_circ_0011290 在这种疾病中的表达状态和功能贡献，特别是通过海绵 RNA 的作用模式。
通过实时聚合酶链反应定量检测 hsa_circ_0011290、microRNA (miR)-1252 和 Follistatin Like 1 (FSTL1) 的相对表达。通过葡萄糖摄取、乳酸生成和 ATP 含量的检测来确定葡萄糖代谢。通过荧光素酶报告基因检测来研究 miR-1252 对 hsa_circ_0011290 和 Follistatin Like 1 (FSTL1) 的调节作用。通过 RNA 下拉实验分析 miR-1252 与 hsa_circ_0011290 和 FSTL1 转录本之间的直接结合。通过 Western blot 检测 FSTL1 蛋白水平。
hsa_circ_0011290 的异常过表达与 PTC 的晚期阶段和不良预后相关。hsa_circ_0011290 的敲低极大地抑制了 PTC 细胞的活力、增殖，并刺激了细胞凋亡。同时，葡萄糖代谢明显改变，葡萄糖摄取和乳酸生成减少，ATP 含量增加。我们确定 miR-1252 是 hsa_circ_0011290 的靶 miR，miR-1252 明显抑制了荧光素酶报告基因和内源性 hsa_circ_0011290 的表达，miR-1252 被 hsa_circ_0011290 负调控，反之亦然。我们进一步提出 FSTL1 是 miR-1252 的直接靶标，并提供了直接证据支持 miR-1252 与 hsa_circ_0011290 和 FSTL1 之间的结合。通过海绵 miR-1252，hsa_circ_0011290 能够正向调节 FSTL1 的表达。值得注意的是，抑制 miR-1252 完全逆转了 hsa_circ_0011290 敲低的表型效应，包括细胞活力、增殖、凋亡和葡萄糖代谢。
我们的研究揭示了 hsa_circ_0011290-miR-1252-FSTL1 在 PTCs 中的致癌作用。
