To investigate whether expression of Gli1, a transactivator of Hh signalling, can suppress Wnt signalling and inhibit proliferation of human colorectal cancer cells.
Advanced basal cell carcinomas (BCCs) circumvent Smoothened (SMO) inhibition by activating GLI transcription factors to sustain the high levels of Hedgehog (HH) signaling required for their survival.
Here, we show that PCAF can directly acetylate cytoplasmic GLI1 protein at lysine 518, preventing its nuclear translocation and promoter occupancy, and consequently suppressing Hedgehog (Hh) signaling in HCC.
Glioma-associated oncogene homologue (Gli) reporter assay, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay, and quantitative real-time reverse transcription-PCR for the target genes of the Hh signals were performed in HHIP stably expressing hepatoma cells.
TNF-α activated Hedgehog (Hh) signaling by enhancing Gli1 nuclear translocation and transcriptional activity, which resulted in increased invasiveness; these effects were blocked by daidzein and the Hh signaling inhibitors, cyclopamine and vismodegib.
Together our data support a model in which the Gli code, and Gli1 in particular, acts as a key sensor that responds to both Hh signals and the oncogenic load.
The transcription factor glioma-associated oncogene 1 (Gli1) has been recognized as a very important nuclear executor at the distal end of the Hedgehog (Hh) signal pathway, which has crucial roles in regulating many developmental processes, such as pattern formation, differentiation, proliferation, and apoptosis.
GLI1 is a key downstream transcription effector of the Hedgehog (Hh) signaling pathway that is involved in promoting cell growth, differentiation and tissue patterning in embryonic development.
Zinc finger-containing Gli proteins mediate responsiveness to Hedgehog (Hh) signaling, with Gli2 acting as the major transcriptional activator in this pathway in mice.
SE exerted these activities through the activation of the Hedgehog (Hh) signaling pathway by restoring Smo ((2.1 ± 0.2)-fold, P < 0.05) and Gli1 ((2.8 ± 0.1)-fold, P < 0.05) expression, which was suppressed by adipogenic signals.
While in cortisol-producing adenomas (CPA), Hh-signaling expression levels were comparable to that in normal adrenal cortex, a much higher mRNA expression of GLI1, SMO and SHH was observed in non-producing adenomas (NPA).
Interestingly, these cells also express the Hh receptor Patched and the downstream signalling components Smoothened and Gli1, suggesting autocrine Hh signalling in these cells.
Conversely, deletion of the zinc finger domain at C-terminus of Zic2 significantly abrogated its interaction with Gli1, the retention of Gli1 in the nucleus, effects on Hh signalling activity and oncogenic properties in cervical cancer cells.
In the present study, we show that concomitant inhibition of Hedgehog (HH) signaling by the glioma-associated oncogene homolog1 (GLI1)-targeting agent GANT61 and the antiapoptotic BCL-2 protein family member MCL-1 by A-1210477 synergistically induces cell death in HH-driven cancers, i.e. rhabdomyosarcoma (RMS) and medulloblastoma (MB) cells.
We then summarise the latest advances on SMO and GLI inhibitors and alternative approaches to attenuate HH signalling through rational combinatorial therapies.
Transcriptional regulation of the Hedgehog (HH) signaling response is mediated by GLI genes (GLI1, GLI2) downstream of SMO, that are also activated by oncogenic signaling pathways.
The hedgehog (HH) signalling pathway, which includes the transcription factor glioma-associated oncogene homolog 1 (GLI1), plays vital roles in gastrointestinal tract development, homeostasis, and malignancy.
We have found that abnormal expression of the hedgehog (Hh) signaling pathway transcription factor Gli1 is involved in the regulation of ABC transporters ABCB1 and ABCG2 in ovarian cancer.
Canonical Hedgehog (HH) signaling is characterized by Smoothened (Smo)-dependent activation of the transcription factors Gli1 and Gli2, which regulate HH target genes.
As a physically binding protein of GLI1 transcription factor, Suppressor-of-Fused (SUFU) has been placed in the center of negative regulation of Hedgehog (Hh) signaling.