Orchestrating spatial and temporal gene expression: LncRNAs as the critical minority of master regulators

Long non-coding RNAs (lncRNAs), as a “critical minority”, exert a core regulatory role in the spatiotemporal control of gene expression by virtue of their distinct structural characteristics and advantageous subcellular localization in both the nucleus and cytoplasm. Guided by the Pareto distribution principle and the central dogma, this review systematically explores the multidimensional regulatory mechanisms of lncRNAs. It covers their functions in chromatin remodeling, the dynamic assembly of transcription factories, and post-transcriptional regulation. In the spatial dimension, lncRNAs modulate higher-order chromatin structure and accessibility through multiple mechanisms. These include: (1) forming biomolecular condensates via liquid-liquid phase separation (LLPS) with partners such as transcription and splicing factors; (2) directing the targeting of chromatin-modifying enzymes; and (3) facilitating the formation of specialized structures, including R-loops and DNA-RNA triplexes. At the post-transcriptional modification level, lncRNAs can undergo chemical modifications like N 6 -methyladenosine ( m 6 A ) and 5-methylcytosine ( m 5 C ) to regulate their own stability and function. They also recruit modifying enzymes or reader proteins to mediate the diversity and stability of target mRNAs, thereby constructing intricate epigenetic regulatory networks. Furthermore, lncRNAs participate in the entire cascade of gene expression, from transcription initiation and elongation to post-transcriptional maturation, by regulating alternative splicing, transcription factor activity, and RNA polymerase II function. These multi-dimensional regulatory mechanisms highlight the pivotal role of lncRNAs in tumorigenesis and progression, providing not only new perspectives for deciphering the complexity of gene expression but also potential avenues for the precise diagnosis and targeted therapy of tumors. Meanwhile, they expand emerging scientific frontiers that require further in-depth investigation, including lncRNA-mediated dynamic regulation of phase separation and the selective targeting of modification sites. • LncRNAs, a "critical minority" in gene expression networks, reflect the applicability of the Pareto principle in microcosm. • Acting as guides, housekeepers, and scissors, they spatiotemporally orchestrate transcriptional and pre-translational events. • Bridging mechanistic hubs and clinics, lncRNAs offer a new translational frontier for diagnostics, therapy, and delivery.