miR-132 weakens proliferation and invasion of glioma cells via the inhibition of Gli1.

OBJECTIVE: Transcriptional factor Gli1 in Hedgehog signal pathway facilitates epithelial mesenchymal transition (EMT) and is associated with invasion or proliferation of multiple tumor cells. The previous study showed the correlation between miR-132 down-regulation and glioma pathogenesis. We investigated the role of miR-132 in mediating Gli1 expression and in affecting proliferation or invasion of glioma cells. PATIENTS AND METHODS: Dual luciferase reporter gene assay was used to confirm the targeted regulation between miR-132 and Gli1. Tumor tissues at different pathological grades (grade II, III and IV) were collected from glioma patients, in parallel with brain tissues from contusion surgery. The expression of miR-132 and Gli1 was measured by RT-PCR. Glioma cell line U251 was treated with miR-132 or si-Gli1 followed by measuring the expression of Gli1, E-cadherin, Vimentin and Cyclin D1. In addition, flow cytometry and transwell assay were performed to evaluate cell invasion potency. RESULTS: Bioinformatics analysis showed the complementary binding sites between miR-132 and 3'-UTR of Gli1 mRNA. Transfection of miR-132 mimic significantly reduced luciferase activity, indicating the targeted regulatory relationship between miR-132 and Gli1 mRNA. Compared with control group, miR-132 expression was decreased and Gli1 level was elevated in glioma tissues, both of which were correlated with the pathological grade. Transfection of miR-132 mimic or si-Gli1 remarkably suppressed the expression of Gli1, Vimentin or Cyclin D1 in U251 cells, up-regulated E-cadherin expression, suppressed cell proliferation and invasion. CONCLUSIONS: Our data indicated that over-expression of miR-132 could inhibit proliferation or invasion of glioma cells via targeted inhibition of Gli1 expression.

Carnosol inhibits Hedgehog signaling pathway in both LNCaP and DU145 prostate cancer cell lines.

To investigate the effect of carnosol on the Hedgehog (HH) signaling pathway in human hormone-dependent prostate cancer cell line LNCaP and hormone-independent prostate cancer cell line DU145. The expression levels of glioma-associated oncogene homolog 1 (Gli1) and Sonic hedgehog (Shh) in human prostate cancer tissues were detected by immunohistochemistry. After treated with carnosol (0.25-16 µmol/L), the cell survival of LNCaP and DU145 cells were detected by MTT assay. The expression levels of Gli1 and Shh mRNA and protein in the two cells were detected by qRT-PCR and western blot, respectively. The apoptosis was determined by the caspase-3 activity assay. Results showed that Shh and Gli1 were upregulated in cancer tissues. The inhibitory effect of carnosol on cell survival was enhanced with concentration, suggesting both LNCaP and DU145 cells were sensitive to carnosol. The inhibitory effects of carnosol on Gli1 and Shh mRNAs in the hormone-dependent LNCaP prostate cancer cell was stronger than that in the hormone-independent DU145 prostate cancer cells. Carnosol downregulated the expression of Gli1 in nucleus, and Shh in cells. Greater carnosol concentration resulted in lower levels of Gli1 and Shh. Carnosol increased caspase-3 activity in a dose-dependent manner, suggesting that carnosol promotes cell apoptosis. Thus, carnosol can inhibit the proliferation and induce the apoptosis of prostate cancer cells in vitro, and its mechanism might be associated with the inhibiting of HH signaling pathway. Although the inhibitory effect of carnosol on hormone-dependent LNCaP prostate cancer cells is stronger than hormone-independent DU145 prostate cancer cells, carnosol might be a potential drug for hormone-independent prostate cancer.

Nuclear expression of Gli-1 is predictive of pathologic complete response to chemoradiation in trimodality treated oesophageal cancer patients.

BACKGROUND: Predictive biomarkers or signature(s) for oesophageal cancer (OC) patients undergoing preoperative therapy could help administration of effective therapy, avoidance of ineffective ones, and establishment new strategies. Since the hedgehog pathway is often upregulated in OC, we examined its transcriptional factor, Gli-1, which confers therapy resistance, we wanted to assess Gli-1 as a predictive biomarker for chemoradiation response and validate it. METHODS: Untreated OC tissues from patients who underwent chemoradiation and surgery were assessed for nuclear Gli-1 by immunohistochemistry and labelling indices (LIs) were correlated with pathologic complete response (pathCR) or

Potential role of Shh-Gli1-BMI1 signaling pathway nexus in glioma chemoresistance.

Chemoresistance is a common hurdle for the proper treatment of gliomas. The role of Shh-Gli1 signaling in glioma progression has been reported. However, its role in glioma chemoresistance has not been well studied yet. In this work, we found that Shh-Gli1 signaling regulates the expression of one stem cell marker, BMI1 (B cell-specific Moloney murine leukemia virus), in glioma. Interestingly, we also demonstrated high expression of MRP1 (multi-drug resistance protein 1) in glioma. MRP1 expression was decreased by BMI1 siRNA and Shh-Gli1 cell signaling specific inhibitor GANT61 in our experiments. GANT61 very efficiently inhibited cell colony growth in glioma cell lines, compared to temozolomide. Moreover, a synergic effect of GANT61 and temozolomide drastically decreased the LD50 of temozolomide in the cell colony experiments. Therefore, our results suggest that there is a potential nexus of Shh-Gli1-BMI1 cell signaling to regulate MRP1 and to promote chemoresistance in glioma. Henceforth, our study opens the possibility of facing new targets, Gli1 and BMI1, for the effective treatment of glioma suppression of chemoresistance with adjuvant therapy of GANT61 and temozolomide.

The Effect of SHH-Gli Signaling Pathway on the Synovial Fibroblast Proliferation in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by chronic synovitis. This study aims to investigate the role of sonic hedgehog (SHH)-Gli signaling pathway in synovial fibroblast proliferation in rheumatoid arthritis. The expression of serum SHH in RA patients group was significantly increased compared with the systemic lupus erythematosus (SLE), ankylosing spondylitis (AS), and healthy subject (healthy control, HC) groups, respectively; serum SHH expression of RA patients was positively correlated with rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibodies (anti-CCP Ab), while there was no significant correlation between SHH expression and erythrocyte sedimentation rate (ESR). SHH, Ptch, Smo, and Gli molecules were highly expressed in rat RA-synovial fibroblast (RA-SF); after blocking the SHH-Gli signaling pathway with a Gli specific inhibitor, Gli-antagonist 61 (GANT61), RA-SF proliferation was inhibited in a dose-dependent manner and the apoptosis rate of RA-SF was increased as well; the expression levels of fibroblast growth factor receptor 1 (FGFR1) and FGFR3 declined in SF cells after GANT61 treatment. Our results suggest that SHH-Gli pathway is involved in the pathogenesis of RA, and blocking SHH-Gli pathway inhibits RA-SF cell proliferation and increases cell apoptosis, which may shed light on developing new ideas for RA treatment.