CELF6 modulates triple-negative breast cancer progression by regulating the stability of FBP1 mRNA

CELF6 modulates triple-negative breast cancer progression by regulating the stability of FBP1 mRNA

Background Triple-negative breast cancer (TNBC) remains a great challenge in clinical treatment due to a shortage of effective therapeutic targets and acquired chemoresistance. Here, we identified the role of an RNA-binding protein, CUG-BP Elav-like family member 6 (CELF6), in the TNBC development and paclitaxel (PTX) chemoresistance. Methods Stable CELF6-overexpressing cell lines were established in BT549 and MDA-MB-231 cells. Cell proliferation was determined using cell counting, two-dimensional colony formation, and MTT assay. Meanwhile, cell migration and cell invasion were detected by Transwell assay. Furthermore, the downstream target gene of CELF6 was identified and the direct interaction was further determined by luciferase reporter assay, immunoprecipitation, and RNA pull-down. Additionally, the PTX resistant cell line was established to determine the role of CELF6 in PTX resistance. Results CELF6 overexpression suppressed cell proliferation, cell migration, and cell invasion. Mechanistically, Fructose-Bisphosphatase 1 (FBP1) was identified as the target gene of CELF6 and stabilized by CELF6 via binding 3′UTR. CELF6 overexpression mediated inhibition in TNBC development was dependent on FBP1. Moreover, CELF6 overexpression increased the sensitivity to PTX treatment. Conclusion CELF6 functions as a tumor suppressor by upregulating FBP 1 expression via stabilizing its mRNA, and thereby inhibits TNBC progression.

背景 三阴性乳腺癌（TNBC）由于缺乏有效的治疗靶点以及获得性化疗耐药性，在临床治疗中仍然是一个巨大的挑战。在此，我们确定了一种RNA结合蛋白——CUG - BP Elav样家族成员6（CELF6）在TNBC发展和紫杉醇（PTX）化疗耐药性中的作用。 方法 在BT549和MDA - MB - 231细胞中建立稳定过表达CELF6的细胞系。通过细胞计数、二维集落形成和MTT法测定细胞增殖。同时，通过Transwell实验检测细胞迁移和细胞侵袭。此外，确定CELF6的下游靶基因，并通过荧光素酶报告基因实验、免疫沉淀和RNA下拉实验进一步确定直接相互作用。另外，建立紫杉醇耐药细胞系以确定CELF6在紫杉醇耐药中的作用。 结果 CELF6过表达抑制细胞增殖、细胞迁移和细胞侵袭。从机制上讲，果糖 - 二磷酸酶1（FBP1）被确定为CELF6的靶基因，并且CELF6通过结合3′UTR使其稳定。CELF6过表达对TNBC发展的抑制作用依赖于FBP1。此外，CELF6过表达增加了对紫杉醇治疗的敏感性。 结论 CELF6通过稳定其mRNA上调FBP1表达而发挥肿瘤抑制作用，从而抑制TNBC进展。