Long intergenic non-protein coding RNA 393 (LINC00393)

Long intergenic non-protein coding RNA 393 (LINC00393) is a human long non-coding RNA gene located on chromosome 13 (13q22), spanning positions 73,412,982 to 73,662,210 on the reverse strand[1][3][5]. It encodes a lncRNA transcript but does not produce a protein product. LINC00393 is mainly of functional interest in cancer biology: it features prominently as a molecular subclass marker in triple-negative breast cancer (TNBC) and is considered part of a distinct "LINC00393-enriched" TNBC subtype[2]. This subset is associated with enrichment in serine-type endopeptidase activity, activation of cell cycle genes, and tends to show poor prognosis with worse patient outcomes[2]. LINC00393 expression is also noted in the tumor microenvironment—its function in epithelial cancer cells remains less experimentally explored but may involve regulation of pro-angiogenic factors such as VEGFA and cancer stem cell markers such as PROM1/CD133[2]. Additionally, in the context of cervical cancer, integration of high-risk HPV with the LINC00393 locus can alter chromatin architecture, affecting nearby transcription factors such as KLF12 and potentially contributing to oncogenesis[4]. There are no drugs currently known to directly target LINC00393, nor are there established mechanisms of pharmacological action or major safety concerns associated with this lncRNA as a clinical therapeutic target to date[2][4]. However, its expression profile suggests utility as a biomarker for disease classification and outcome prediction in selected cancers[2].