Wang Mohan, Zheng Shanshan, Zhang Yan, Zhang Jingwen, Lai Fuming, Zhou Cong, Zhou Qiangwei, Li Xingwang, Li Guoliang
National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
Agricultural Bioinformatics Key Laboratory of Hubei Province, Hubei Engineering Technology Research Center of Agricultural Big Data, Key Laboratory of Smart Farming Technology for Agricultural Animals, 3D Genomics Research Center, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China.
BMC Biol. 2025 May 12;23(1):127. doi: 10.1186/s12915-025-02233-8.
Circular RNAs (circRNAs) are a class of non-coding RNAs generated through back splicing. High expression of circRNAs is often associated with numerous abnormal cellular biological processes. However, the regulatory factors of circRNAs are not fully understood.
In this study, we identified PTBP1 as a crucial regulator of circRNA biogenesis through a comprehensive analysis of the whole transcriptome profiles across 10 diverse cell lines. Knockdown of PTBP1 led to a significant decrease in circRNA expression, concomitant with a distinct reduction in cell proliferation. To investigate the regulatory mechanism of PTBP1 on circRNA biogenesis, we constructed a minigene reporter based on SPPL3 gene. The results showed that PTBP1 can bind to the flanking introns of circSPPL3, and the mutation of PTBP1 motif impedes the back splicing of circSPPL3. Subsequently, to demonstrate that this observation is not an exception, the comprehensive regulatory effects of PTBP1 on circRNAs were confirmed by miniGFP, reflecting the necessity of the binding site in the flanking introns. Analysis of data from clinical samples showed that both PTBP1 and circRNAs exhibited substantial upregulation in acute myeloid leukemia, further demonstrating a potential role for PTBP1 in promoting circRNA biogenesis under in vivo conditions. Competitive endogenous RNA (ceRNA) network revealed that PTBP1-associated circRNAs participated in biological processes associated with cell proliferation.
In summary, our study is the first to identify the regulatory effect of PTBP1 on circRNA biogenesis and indicates a possible link between PTBP1 and circRNA expression in leukemia.
环状RNA（circRNAs）是一类通过反向剪接产生的非编码RNA。circRNAs的高表达通常与众多异常细胞生物学过程相关。然而，circRNAs的调控因子尚未完全明确。
在本研究中，我们通过对10种不同细胞系的全转录组图谱进行综合分析，确定PTBP1是circRNA生物合成的关键调控因子。敲低PTBP1导致circRNA表达显著降低，同时细胞增殖明显减少。为了研究PTBP1对circRNA生物合成的调控机制，我们基于SPPL3基因构建了一个小基因报告载体。结果表明，PTBP1可以结合circSPPL3侧翼内含子，PTBP1基序的突变会阻碍circSPPL3的反向剪接。随后，为了证明这一观察结果并非个例，miniGFP证实了PTBP1对circRNAs的综合调控作用，这反映了侧翼内含子中结合位点的必要性。临床样本数据分析表明，PTBP1和circRNAs在急性髓系白血病中均显著上调，进一步证明了PTBP1在体内条件下促进circRNA生物合成中的潜在作用。竞争性内源RNA（ceRNA）网络显示，与PTBP1相关的circRNAs参与了与细胞增殖相关的生物学过程。
总之，我们的研究首次确定了PTBP1对circRNA生物合成的调控作用，并表明PTBP1与白血病中circRNA表达之间可能存在联系。
