H19

H19 is a long non-coding RNA (lncRNA) gene located on chromosome 11p15.5 in humans. It is an imprinted gene, meaning that it is expressed in a parent-of-origin-specific manner. H19 is expressed from the maternal allele, while the paternal allele is typically silenced. This gene plays a crucial role in embryonic development and growth regulation.

Function

H19 is primarily known for its role in the regulation of growth and development. It is highly expressed during embryogenesis and is downregulated after birth. The H19 gene produces a non-coding RNA that is not translated into protein but functions as a regulatory RNA. It is involved in the regulation of imprinted genes and interacts with various molecular pathways to influence cell proliferation and differentiation.

H19 is also implicated in the regulation of the insulin-like growth factor 2 (IGF2) gene, which is located nearby on the same chromosome. The expression of H19 and IGF2 is reciprocally regulated through a shared imprinting control region (ICR), known as the H19/IGF2 ICR.

Clinical Significance

H19 has been associated with several human diseases, particularly those involving abnormal growth and development. It is implicated in Beckwith-Wiedemann syndrome, a disorder characterized by overgrowth and an increased risk of childhood tumors. Abnormal expression of H19 has also been observed in various cancers, including hepatocellular carcinoma, bladder cancer, and breast cancer.

In cancer, H19 can act as an oncogene or a tumor suppressor, depending on the context. It is involved in the regulation of cell proliferation, apoptosis, and metastasis. The H19 RNA can also serve as a precursor for microRNA-675, which has its own regulatory functions in cancer biology.

Research and Therapeutic Potential

Due to its involvement in growth regulation and cancer, H19 is a target of interest for therapeutic interventions. Strategies to modulate H19 expression or function are being explored as potential treatments for cancer and other diseases associated with abnormal imprinting.

Also see

• Imprinted genes
• Long non-coding RNA
• Beckwith-Wiedemann syndrome
• Insulin-like growth factor 2
• Epigenetics