High mobility group protein A2 (HMGA2)

High mobility group protein A2 (HMGA2) is an architectural transcription factor that modulates gene expression by altering the global chromatin structure [UniProt: P52926]. It contains three specialized 'AT-hook' domains that bind to the minor groove of AT-rich DNA sequences, facilitating the recruitment and assembly of multi-protein transcription complexes at promoter and enhancer regions [PubMed: 12514193]. While HMGA2 is highly expressed during embryonic development, its expression is nearly undetectable in most adult tissues, making it a classic oncofetal protein [PubMed: 28249057]. In clinical pathology, HMGA2 is frequently overexpressed or rearranged in mesenchymal tumors like lipomas and leiomyomas, as well as aggressive epithelial carcinomas, where it drives the epithelial-mesenchymal transition (EMT) and promotes chemoresistance [NCBI Gene ID: 8091]. Its role in maintaining cancer cell stemness and facilitating metastasis makes it a high-priority therapeutic target, particularly in refractory cancers. Current therapeutic strategies focus on restoring let-7 microRNA levels to silence HMGA2 post-transcriptionally or using DNA minor groove binders to disrupt its binding capacity, although its nature as a non-enzymatic protein presents significant 'undruggable' challenges for traditional drug discovery [PubMed: 23640030]. Monitoring HMGA2 levels and its associated fusion transcripts serves as a critical biomarker for diagnosis, prognosis, and therapeutic stratification in various malignancies.

Other names

HMGI-CHMGICBABLLIPOHigh mobility group AT-hook protein 2

Drugs targeting HMGA2 typically function by either restoring let-7 microRNA levels to induce post-transcriptional silencing and mRNA degradation, or by utilizing small-molecule minor groove binders that competitively displace the protein's AT-hook domains from DNA, thereby disrupting its ability to organize enhanceosomes [PubMed: 23640030, PubMed: 12514193].