Zhang Hai-Bo, Zeng Ying, Wang Guo
Department of Pharmacy, Hangzhou Women's Hospital (Hangzhou Maternity and Child Health Care Hospital), Hangzhou, China.
Department of Pharmacy, Hengyang Medical School, The Affiliated Changsha Central Hospital, University of South China, Changsha, China.
World J Surg Oncol. 2025 Jul 19;23(1):289. doi: 10.1186/s12957-025-03944-6.
Breast cancer (BC) is a malignant tumor seriously threatening women's health, while current approaches to BC treatment are challenged by the existence of drug resistance. Combination strategies of targeted therapy have been successfully applied in clinical BC treatment. However, whether there exist critical long non-coding RNAs (lncRNAs) responsible for BC pathogenesis and representing promising candidates for combined targeted therapy remains an issue.
Public databases and bioinformatic methods were used to identify lncRNAs abnormally expressed among different subtypes of BC. The expression level of PVT1 was verified in collected clinical samples and representative cell lines. The role of PVT1 in BC cell proliferation was examined using MTS, plate clone formation, EdU and flow cytometry assay after small interfering RNA (siRNA) treatment. RNA sequencing was performed to investigate the potential molecular events regulated by PVT1. Western blot and immunofluorescence experiments were used to verify the activation of LATS2/Hippo signaling pathway after PVT1 knockdown. In addition, its activation was confirmed to mediate PVT1 function through rescue assay. The regulatory effect of PVT1 on LATS2 was investigated using mRNA stability experiments.
The expression level of PVT1 in BC tissues of luminal and basal-like subtypes was significantly higher than that in paracancerous tissues. PVT1 knockdown substantially inhibited the proliferation of BC cells in both subtypes. RNA sequencing revealed that Hippo signaling pathway might be the downstream target of PVT1. After PVT1 knockdown, both mRNA and protein levels of LATS2 were elevated which further decreased the distribution of YAP in cell nucleus, indicating the activation of Hippo signaling pathway. The proliferation inhibitory effect of PVT1 could be attenuated by simultaneous knockdown of LATS2. Furthermore, knockdown of PVT1 was demonstrated to significantly slow down the degradation rate of LATS2 mRNA.
PVT1 level was significantly elevated in luminal and basal-like BC subtypes. Knockdown of PVT1 could inhibit cell proliferation of these two BC subtypes partly through activating LATS2/Hippo signaling pathway.
乳腺癌（BC）是严重威胁女性健康的恶性肿瘤，而当前的BC治疗方法面临着耐药性的挑战。靶向治疗的联合策略已成功应用于临床BC治疗。然而，是否存在负责BC发病机制并代表联合靶向治疗有前景候选物的关键长链非编码RNA（lncRNAs）仍是一个问题。
利用公共数据库和生物信息学方法鉴定在不同BC亚型中异常表达的lncRNAs。在收集的临床样本和代表性细胞系中验证PVT1的表达水平。在小干扰RNA（siRNA）处理后，使用MTS、平板克隆形成、EdU和流式细胞术检测法检测PVT1在BC细胞增殖中的作用。进行RNA测序以研究受PVT1调控的潜在分子事件。使用蛋白质免疫印迹和免疫荧光实验验证PVT1敲低后LATS2/ Hippo信号通路的激活。此外，通过拯救实验证实其激活介导PVT1功能。使用mRNA稳定性实验研究PVT1对LATS2的调控作用。
管腔型和基底样亚型的BC组织中PVT1的表达水平显著高于癌旁组织。PVT1敲低在两种亚型中均显著抑制BC细胞的增殖。RNA测序显示Hippo信号通路可能是PVT1的下游靶点。PVT1敲低后，LATS2的mRNA和蛋白水平均升高，这进一步降低了YAP在细胞核中的分布，表明Hippo信号通路的激活。同时敲低LATS2可减弱PVT1的增殖抑制作用。此外，证明敲低PVT1可显著减慢LATS2 mRNA的降解速率。
管腔型和基底样BC亚型中PVT1水平显著升高。敲低PVT1可部分通过激活LATS2/ Hippo信号通路抑制这两种BC亚型的细胞增殖。
