Department of Thoracic Surgery, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, 241001, China.
Department of Gastrointestinal Surgery, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, 241001, China.
Cell Commun Signal. 2024 Jan 22;22(1):60. doi: 10.1186/s12964-024-01475-3.
Increasing evidence has indicated that long non-coding RNAs (lncRNAs) have been proven to regulate esophageal cancer progression. The lncRNA protein disulfide isomerase family A member 3 pseudogene 1 (PDIA3P1) has been shown to promote cancer stem cell properties; however, its mechanism of action remains unclear. In this study, we investigated the regulation of esophageal cancer stem cell properties by the interaction of PDIA3P1 with proteins.
The GEPIA2 and Gene Expression Omnibus databases were used to analyze gene expression. PDIA3P1 expression in human esophageal squamous cell carcinoma (ESCC) tissues and cell lines was detected by quantitative real-time polymerase chain reaction (qRT-PCR). Loss-of-function experiments were performed to determine the effects of PDIA3P1 on ESCC cell proliferation, migration, and invasion. The sphere formation assay, number of side population cells, and CD271 + /CD44 + cells were detected by flow cytometry to identify the cancer stem cell properties. RNA immunoprecipitation (RIP), RNA pull-down, co-immunoprecipitation (co-IP), dual luciferase reporter, and cleavage under targets and tagmentation (CUT&Tag) assays were performed to elucidate the underlying molecular mechanisms.
PDIA3P1 expression was upregulated in ESCC cell lines and tissues. Functionally, higher PDIA3P1 expression promoted cell proliferation, invasion, and metastasis and inhibited apoptosis in esophageal cancer. Importantly, PDIA3P1 promoted cancer stem cell properties in ESCC. Mechanistically, PDIA3P1 interacted with and stabilized octamer-binding transcription factor 4 (OCT4) by eliminating its ubiquitination by the ubiquitinating enzyme WW domain-containing protein 2 (WWP2). Moreover, as a transcription factor, OCT4 bound to the PDIA3P1 promoter and promoted its transcription.
Our research revealed a novel mechanism by which a positive feedback loop exists between PDIA3P1 and OCT4. It also demonstrated that the PDIA3P1-WWP2-OCT4 loop is beneficial for promoting the cancer stem cell properties of ESCC. Owing to this regulatory relationship, the PDIA3P1-WWP2-OCT4-positive feedback loop might be used in the diagnosis and prognosis, as well as in the development of novel therapeutics for esophageal cancer.
越来越多的证据表明，长非编码 RNA（lncRNA）已被证明可以调节食管癌的进展。蛋白二硫键异构酶家族 A 成员 3 假基因 1（PDIA3P1）已被证明能促进癌症干细胞特性；然而，其作用机制尚不清楚。在这项研究中，我们研究了 PDIA3P1 与蛋白质相互作用对食管癌细胞干性的调节作用。
使用 GEPIA2 和基因表达综合数据库分析基因表达。通过定量实时聚合酶链反应（qRT-PCR）检测人食管鳞状细胞癌（ESCC）组织和细胞系中 PDIA3P1 的表达。通过失活功能实验确定 PDIA3P1 对 ESCC 细胞增殖、迁移和侵袭的影响。通过流式细胞术检测球体形成实验、侧群细胞数和 CD271+/CD44+细胞，以鉴定癌症干细胞特性。进行 RNA 免疫沉淀（RIP）、RNA 下拉、共免疫沉淀（co-IP）、双荧光素酶报告和切割靶向和标签（CUT&Tag）测定，以阐明潜在的分子机制。
PDIA3P1 在 ESCC 细胞系和组织中表达上调。功能上，较高的 PDIA3P1 表达促进了食管癌细胞的增殖、侵袭和转移，并抑制了凋亡。重要的是，PDIA3P1 促进了 ESCC 中的癌症干细胞特性。在机制上，PDIA3P1 通过消除泛素连接酶 WW 结构域蛋白 2（WWP2）对其的泛素化，与八聚体结合转录因子 4（OCT4）相互作用并稳定其。此外，作为转录因子，OCT4 结合 PDIA3P1 启动子并促进其转录。
我们的研究揭示了 PDIA3P1 和 OCT4 之间存在正反馈环的新机制。它还表明，PDIA3P1-WWP2-OCT4 环有利于促进 ESCC 的癌症干细胞特性。由于这种调节关系，PDIA3P1-WWP2-OCT4 正反馈环可用于食管癌的诊断和预后，以及开发新的治疗方法。
