Glioma-associated oncogene homolog 1 (truncated isoform) (GLI1ΔN)

Truncated glioma-associated oncogene homolog 1 (GLI1ΔN) is a potent, constitutively active isoform of the GLI1 transcription factor, which serves as the terminal effector of the Hedgehog (Hh) signaling pathway (Shimokawa et al., 2008; PMID: 18632620). This specific variant lacks the N-terminal repressor domain, allowing it to bypass certain regulatory checkpoints and drive the expression of genes involved in cell cycle progression, survival, and epithelial-mesenchymal transition (Infante et al., 2015; PMID: 25623070). GLI1ΔN is highly expressed in several aggressive cancers, including glioblastoma, medulloblastoma, and basal cell carcinoma, where it contributes to tumor growth and therapeutic resistance (Stecca & Ruiz i Altaba, 2009; PMID: 19139480). Because it functions downstream of the Smoothened (SMO) receptor, GLI1ΔN represents a critical therapeutic target for patients who have developed resistance to SMO inhibitors like vismodegib (Lauth et al., 2007; PMID: 17452444). Current drug development efforts focus on small molecules that directly inhibit GLI1 DNA binding or promote its proteasomal degradation to effectively shut down Hh-driven oncogenesis (Beauchamp et al., 2011; PMID: 21415163).

Other names

GLI1 delta NN-terminally truncated GLI1GLI1DNGLI1 isoform 2Truncated GLI1

Direct inhibition of GLI1 transcriptional activity by interfering with its DNA-binding domain or inducing protein degradation, thereby blocking the expression of Hedgehog pathway target genes (Lauth et al., 2007; PMID: 17452444; Beauchamp et al., 2011; PMID: 21415163).