Department of Gastroenterology, The Second Affiliated Hospital of Xi'an Jiaotong University, 157 Xi Wu Road, Xi'an, 710003, Shaanxi, China.
J Mol Histol. 2024 Feb;55(1):83-96. doi: 10.1007/s10735-023-10173-2. Epub 2024 Jan 2.
Acquired drug resistance is a main reason for limiting the application of sorafenib in HCC treatment. This study aimed to explore the role and mechanisms of a novel long non-coding RNA (lncRNA), lnc-TSI, in sorafenib resistance of HCC. The interaction between lnc-TSI and miR-4726-5p, and miR-4726-5p and KCNMA1 were predicted using bioinformatic tools. Expression of the molecules in the lnc-TSI/miR-4726-5p/KCNMA1 axis in clinical samples and cell lines, as well as the sorafenib resistant HCC cell lines, was determined using qRT-PCR or western blotting. Expressions of lnc-TSI, miR-4726-5p, and KCNMA1 were manipulated in HepG2 and Huh7 cells through plasmid transfection or lentivirus infection. The CCK-8, flow cytometry, and Tunel assays were employed to determine the role of this axis on sorafenib resistance of HCC. A xenograft model was established using sorafenib-resistant HepG2 and Huh7 cells followed by in vivo sorafenib treatments to confirm the in vitro findings. Lnc-TSI and KCNMA1 expressions were significantly downregulated in HCC clinical samples and cell lines, especially in sorafenib resistance ones, while mi-4726-5p presented a reversed expression pattern. Lnc-TSI interacted with miR-4726-5p, and Lnc-TSI acts as a ceRNA via sponging miR-4726-5p in HCC cells. Overexpression of lnc-TSI and KCNMA1 promoted apoptosis and decreased cell viability of sorafenib-treated HCC cells, thus alleviated sorafenib resistance. miR-4726-5p mimic reversed the KCNMA1-mediated sorafenib sensitivity-promoting effect, while additional overexpression of lnc-TSI reversed the effect of miR-4726-5p. In vivo analysis also showed that overexpression of ln-TSI diminished sorafenib resistance in mice inoculated with sorafenib-resistant HCC cells via increasing KCNMA1 expression and decreasing miR-4726-5p expression. The lnc-TSI/miR-4726-5p/KCNMA1 axis plays a critical role in regulating the resistance of HCC to sorafenib, and might serve as a therapeutic target to manage sorafenib resistance of HCC in clinic.
获得性耐药是限制索拉非尼在 HCC 治疗中应用的主要原因。本研究旨在探讨一种新型长非编码 RNA（lncRNA）lnc-TSI 在 HCC 索拉非尼耐药中的作用和机制。利用生物信息学工具预测 lnc-TSI 与 miR-4726-5p 以及 miR-4726-5p 与 KCNMA1 之间的相互作用。采用 qRT-PCR 或 Western blot 检测 lnc-TSI/miR-4726-5p/KCNMA1 轴在临床样本和细胞系以及索拉非尼耐药 HCC 细胞系中的表达。通过质粒转染或慢病毒感染操纵 HepG2 和 Huh7 细胞中的 lnc-TSI、miR-4726-5p 和 KCNMA1 的表达。采用 CCK-8、流式细胞术和 Tunel 检测评估该轴对 HCC 索拉非尼耐药的作用。建立索拉非尼耐药 HepG2 和 Huh7 细胞的异种移植模型，随后进行体内索拉非尼治疗，以验证体外发现。lnc-TSI 和 KCNMA1 的表达在 HCC 临床样本和细胞系中明显下调，尤其是在索拉非尼耐药的细胞系中，而 miR-4726-5p 的表达则呈现相反的表达模式。lnc-TSI 与 miR-4726-5p 相互作用，lnc-TSI 通过海绵吸附 miR-4726-5p 在 HCC 细胞中发挥 ceRNA 作用。lnc-TSI 和 KCNMA1 的过表达促进索拉非尼处理的 HCC 细胞凋亡，降低细胞活力，从而减轻索拉非尼耐药。miR-4726-5p 模拟物逆转了 KCNMA1 介导的索拉非尼敏感性促进作用，而过表达 lnc-TSI 则逆转了 miR-4726-5p 的作用。体内分析还表明，通过增加 KCNMA1 表达和降低 miR-4726-5p 表达，lnc-TSI 的过表达减轻了索拉非尼耐药 HCC 细胞接种小鼠的索拉非尼耐药性。lnc-TSI/miR-4726-5p/KCNMA1 轴在调节 HCC 对索拉非尼的耐药性中起着关键作用，可能成为临床管理 HCC 索拉非尼耐药的治疗靶点。
