HLA complex P5 (non-protein coding) (HCP5)

HLA complex P5 (HCP5) is a long non-coding RNA (lncRNA) gene located within the major histocompatibility complex (MHC) class I region, specifically centromeric to HLA-B and between the MICA and MICB genes. HCP5 is transcribed into a non-coding RNA that contains fragments of an ancestral endogenous retrovirus sequence (HERV16) linked to an HLA class I promoter, but does not encode a functional protein. HCP5 acts as a regulatory RNA, functioning mainly through "sponging" or titrating microRNAs (e.g., miR-22-3p, miR-186-5p, miR-216a-5p), which thereby influences the expression of various genes including those involved in cancer progression (such as ST6GAL2 in thyroid carcinoma). HCP5 is involved in the regulation of immune response and chromatin architecture. Elevated expression of HCP5 has been associated with cancer proliferation, migration, and poor prognosis, notably in follicular thyroid carcinoma, and also with some autoimmune and infectious diseases. HCP5's regulatory functions and disease associations highlight its emerging importance as a potential target for therapeutic intervention and as a biomarker for certain conditions, though direct drug targeting of lncRNAs remains experimental.

Other names

HLA class I histocompatibility antigen protein P5HCPAD6S2650EP5-1HLA complex protein P5Protein P5-16S2650EMHC class I region ORFHCP5

Not applicable for direct drug targeting; acts as a ceRNA modulating the availability of miRNAs that in turn regulate protein-coding genes