Long Non-Coding RNA Rewriting the Network of Metastasis and Drug Resistance
Background
The primary cause of cancer mortality is not the primary tumor itself, but metastatic cancer that spreads to other organs and residual cancer cells that do not respond to treatment. Targeted therapies and immunotherapies have improved treatment outcomes, but cancer cells survive by activating alternative signaling pathways, altering metabolism, and evading immune surveillance. Protein-centric analyses have proven insufficient to fully explain these adaptive processes.
Long non-coding RNA (lncRNA) is generally defined as a transcript longer than 200 nucleotides that does not encode proteins. Once considered transcriptional noise, lncRNAs are now recognized as key regulators of chromatin structure, transcription, RNA stability, and protein activity. The challenge lies in the fact that the same lncRNA can exhibit opposing functions depending on cancer type and cellular context. Bulk tumor analyses may obscure changes specific to a minority of metastatic or resistant cells by averaging them out.
Key Findings
This paper is not a study presenting new patient cohorts or animal experimental results, but a review that systematically organizes recent evidence showing that lncRNAs regulate both cancer metastasis and drug resistance. The authors categorize the functions of lncRNAs into four axes: oncogenic signaling, transcriptional programs, immune cell reprogramming, and metabolic reprogramming.
During metastasis, lncRNAs either promote or inhibit epithelial-mesenchymal transition (EMT), a process in which epithelial cells acquire motility and invasiveness. They recruit specific transcription factors and chromatin regulatory complexes, act as competitive endogenous RNAs by sequestering microRNAs, and alter the stability of signaling proteins. These changes lead to reduced cell adhesion, increased invasion, survival in the bloodstream, and colonization in distant organs.
In drug resistance, lncRNAs are not passive markers. They contribute to drug efflux, DNA damage repair, apoptosis evasion, and stemness maintenance, while also reprogramming related pathways and mitochondrial metabolism. In the tumor microenvironment, they alter the differentiation and function of immune cells and support immune evasion. This suggests that metastasis and resistance are not separate phenomena but overlapping adaptive programs.
Exceptions to the term 'non-coding' have also been highlighted. Some lncRNAs contain short open reading frames that encode functional micropeptides. These peptides can modulate signaling, metabolism, and protein complex formation, suggesting that biological effects may not be fully explained by RNA function alone, and that micropeptide activity must also be considered.
Implications and Outlook
Therapeutic strategies include antisense oligonucleotides (ASO), RNA interference, and CRISPR-based inhibition and editing. The aim is to reduce oncogenic lncRNAs, restore tumor-suppressive lncRNAs, and directly block or supplement lncRNA-derived micropeptides. The fact that lncRNA expression varies by cancer type and treatment response is also advantageous for the development of diagnostic, prognostic, and drug-response biomarkers.
However, there is still a significant gap before clinical translation. LncRNAs are highly context-dependent and influenced by tumor heterogeneity. Delivering therapeutics to nuclear targets selectively is also challenging. Off-target effects, immune responses, and normal tissue toxicity of ASO and CRISPR must be validated. Most importantly, this paper is a review of existing research and does not prove the efficacy of any specific treatment in patients. The next step is to identify lncRNAs in actual resistant cells using single-cell and spatial transcriptomics combined with multi-omics approaches, and to confirm reproducibility in standardized clinical samples.
Metastasis and therapeutic resistance remain the principal causes of cancer-related mortality, reflecting the failure of current therapies to eradicate disseminated and treatment-refractory tumor cells. Long non-coding RNAs, once considered transcriptional noise, have now emerged as pivotal regulators of cancer progression, acting through diverse mechanisms to modulate signaling pathways, transcriptional programs, tumor metabolism, and the tumor microenvironment. Accumulating evidence demonstrates that lncRNAs orchestrate epithelial-mesenchymal transition, metabolic reprogramming, and immune evasion, thereby enabling metastatic dissemination and fostering resistance to chemotherapy. Moreover, recent discoveries have revealed that certain lncRNAs can encode functional micropeptides, further expanding their biological and therapeutic relevance. In this review, we systematically summarize current advances in lncRNA-mediated regulation of cancer metastasis and drug resistance, with particular emphasis on their roles in oncogenic signaling cascades, transcriptional control, immune cell reprogramming, and metabolic remodeling. We also discuss emerging therapeutic strategies targeting lncRNAs, including antisense oligonucleotides, CRISPR-based approaches, and lncRNA-encoded micropeptide interventions. Finally, we highlight key challenges, including context-dependent lncRNA functions, tumor heterogeneity, delivery, off-target effects, and biomarker standardization, and discuss how multi-omics, single-cell, and spatial approaches may facilitate the translation of lncRNA biology into precision oncology.
In clinical settings, measuring changes in lncRNA expression in biopsies or blood before and after treatment is likely to be the first application for early detection of metastatic risk and resistance. For example, patients showing an increase in resistance-associated lncRNAs after a specific anticancer drug treatment could be selected for switching to alternative targeted therapies or combination treatments.
Pharmaceutical companies should evaluate not only individual lncRNAs but also the signaling, metabolic, and immune networks they regulate, as well as whether they encode micropeptides. For ASO or CRISPR candidates to advance to clinical development, tumor-selective delivery systems, companion diagnostic tests, and safety data by cell type must be established.