Guangyuan Central Hospital, Guangyuan, China.
Center for Genome Analysis, Wuhan Ruixing Biotechnology Co., Ltd., Wuhan, China.
PeerJ. 2023 Nov 6;11:e16006. doi: 10.7717/peerj.16006. eCollection 2023.
As the most frequently diagnosed cancer in women, Breast cancer has high mortality and metastasis rate, especially triple-negative breast cancer (TNBC). As an oncogene, protein-L-isoaspartate (D-aspartate) O-methyltransferase (PCMT1) is a prognostic biomarker in breast cancer and is highly expressed, while its underlying functions remain unknown.
In this study, we silenced PCTM1 in TNBC MDA-MB-231 cells by short hairpin RNA (shPCMT1) to investigate its cellular functions using cell proliferation, apoptosis, migration, and invasion experiments. Following this, the transcriptome sequencing (RNA-seq) experiment was conducted to explore the molecular targets of PCMT1, including differentially expressed genes (DEGs) and regulated alternative splicing events (RASEs).
The results showed that shPCMT1 inhibited the proliferation, migration, and invasion of MDA-MB-231 cells. We obtained 1,084 DEGs and 2,287 RASEs between shPCMT1 and negative control (NC) groups through RNA-seq. The DEGs were significantly enriched in immune or inflammation response and cell adhesion-associated pathways, pathways associated with PCMT1 cellular function in cell migration. The RASE genes were enriched in cell cycle-associated pathways and were associated with the altered cell proliferation rate. We finally validated the changed expression and splicing levels of DEGs and RASEs. We found that 34 RNA binding protein (RBP) genes were dysregulated by shPCMT1, including , , , and . The dysregulated RBP genes could partially explain how PCMT1 regulates the global transcriptome profiles.
In conclusion, our study identified the molecular targets of PCMT1 in the TNBC cell line, expands our understanding of the regulatory mechanisms of PCMT1 in cancer progression, and provides novel insights into the progression of TNBC. The identified molecular targets are potential therapeutic targets for future TNBC treatment.
乳腺癌是女性最常见的癌症之一，其死亡率和转移率都很高，尤其是三阴性乳腺癌（TNBC）。蛋白-L-异天冬氨酸（D-天冬氨酸）O-甲基转移酶（PCMT1）作为一种癌基因，是乳腺癌的预后生物标志物，其表达水平较高，但作用机制尚不清楚。
本研究通过短发夹 RNA（shPCMT1）沉默 TNBC MDA-MB-231 细胞中的 PCMT1，利用细胞增殖、凋亡、迁移和侵袭实验来研究其细胞功能。然后，通过转录组测序（RNA-seq）实验来探讨 PCMT1 的分子靶点，包括差异表达基因（DEGs）和调控的可变剪接事件（RASEs）。
shPCMT1 抑制 MDA-MB-231 细胞的增殖、迁移和侵袭。通过 RNA-seq，我们在 shPCMT1 和阴性对照（NC）组之间获得了 1084 个 DEGs 和 2287 个 RASEs。DEGs 显著富集于免疫或炎症反应和细胞黏附相关途径，这些途径与 PCMT1 在细胞迁移中的细胞功能相关。RASE 基因富集于细胞周期相关途径，与改变的细胞增殖率相关。最后，我们验证了 DEGs 和 RASEs 的表达和剪接水平的变化。我们发现 34 个 RNA 结合蛋白（RBP）基因受 shPCMT1 调控，包括 、 、 、 。受 shPCMT1 调控的失调 RBP 基因可以部分解释 PCMT1 如何调节全局转录组谱。
总之，本研究鉴定了 PCMT1 在 TNBC 细胞系中的分子靶点，扩展了我们对 PCMT1 在癌症进展中调控机制的认识，并为 TNBC 的进展提供了新的见解。鉴定的分子靶点可能是未来 TNBC 治疗的潜在治疗靶点。
