Short-lived lncRNAs as candidate kinetic sensors of cellular stress.

Short-lived noncoding transcripts (SLiTs; half-life <4 h) form a kinetically distinct subclass of long noncoding RNAs (lncRNAs) whose rapid turnover is an active regulatory feature rather than a measurement artefact. This review has three objectives: to set out the kinetic basis on which a short half-life supports sensor-like behaviour; to define operational criteria that separate a candidate kinetic sensor from a merely stress-responsive unstable transcript; and to assess the evidence for SLiT involvement across the xenobiotic, oxidative, and proteotoxic stress axes. The evidence differs sharply in weight between axes. Direct mechanistic data exist only for chemical stress in HepG2 cells, where SLiT accumulation arises from transcript stabilisation rather than increased transcription, with impairment of the nuclear exosome and XRN2 as the leading candidate mechanism. The oxidative and proteotoxic axes remain hypothesis-generating. Cross-cell-type and cross-species validation is absent, and the limitations this imposes are stated explicitly.