MicroRNA 105-1 (miR-105-1)

MicroRNA 105-1 (miR-105-1) is a non-coding small RNA molecule (microRNA) of 21–24 nucleotides that regulates gene expression post-transcriptionally by base-pairing with complementary sequences within target mRNAs, leading to gene silencing. Located on chromosome Xq28, it is one of a small family (miR-105-1, miR-105-2, miR-767). MiR-105-1 has key roles in the regulation of cell proliferation, migration, differentiation, apoptosis, and tumorigenesis. In hepatocellular carcinoma, miR-105-1 is typically downregulated compared to normal liver tissue, and low expression is associated with worse prognosis. NCOA1 has been identified as a direct target, and modulation of miR-105-1 using experimental mimics or inhibitors alters tumor cell growth and survival. The activity and prognostic relevance of miR-105-1 extend to other tumor types such as breast, prostate, glioma, and multiple myeloma, where it may serve as a biomarker for disease progression and outcome. Therapeutic targeting is being investigated at the experimental level by manipulating miR-105-1 levels, but its dual role as both tumor suppressor and oncogene depending on cellular context adds complexity to clinical translation. Off-target and pleiotropic effects are notable safety concerns in current therapeutic research.

Other names

miR-105-1MIR105-1hsa-mir-105-1MIRN105-1mir-105-1

miRNA mimics increase miR-105-1 function, leading to silencing of target genes such as NCOA1. miRNA inhibitors reduce its function, potentially increasing proliferation in cancer cells. Indirect targeting through agents affecting DNA methylation (DNMT3A).