Gli1 Expression Research Articles

Saikosaponin b1 Attenuates Liver Fibrosis by Blocking STAT3/Gli1 Interaction and Inducing Gli1 Degradation

ABSTRACTSaikosaponin b1 (Ssb1), a natural oleanane‐type triterpenoid saponin, exhibits antifibrosis activity by inhibiting the activation of hepatic stellate cells (HSCs), but the specific underlying molecular mechanisms are unknown. Here, it is found that Ssb1 could directly bind with the signal transducer and activator of transcription 3 (STAT3) and effectively inhibit the activation of HSCs. Proteomic techniques and molecular simulation revealed that Ssb1 is mainly bound to the S319 residues of STAT3 in the coiled‐coil domain. Further studies indicated that Ssb1 binding with STAT3 inhibited its transcriptional activity, and regulated glioma‐associated oncogene‐1 (Gli1) expression in the Hedgehog signaling pathway. Besides, Ssb1 binding blocked interaction between STAT3 and Gli1, which promoted degradation of Gli1 protein by suppressor of fused homolog (SUFU) and the ubiquitin‐proteasome system. The loss function of Gli1 led to decreased expression of Bcl2 and promoted the apoptosis of activated HSCs. Moreover, STAT3 ablation abolished the Ssb1‐mediated antifibrotic effects. These findings show that STAT3 plays a vital role in Ssb1 treatment of liver fibrosis, and Ssb1 as a STAT3 inhibitor might be a promising therapeutic candidate for the treatment of hepatic fibrosis.

The Hedgehog-GLI1 Pathway Regulates Osteogenic Differentiation of Human Cervical Posterior Longitudinal Ligament Cells by BMP Signalling Pathway.

Cervical ossification of the posterior longitudinal ligament (OPLL) is an ectopic ossification disorder characterised by endochondral ossification. Its aetiology remains to be fully elucidated. This study aimed to clarify its pathogenesis through RNA sequencing of primary cells cultured from patients without cervical OPLL (control, PLL) and patients with cervical OPLL (disease, OPLL). We revealed for the first time the role of GLI1 within OPLL cells. Functional experiments indicated that GLI1, acting as a pivotal mediator between the upstream Hedgehog pathway and downstream BMP pathway, influences the pathogenesis of OPLL. The positive/negative effects on osteogenic differentiation following activation/inhibition of the Hedgehog pathway can be rescued by manipulating GLI1 expression. Overexpression of GLI1 activates BMP signalling, enhancing osteogenic capacity in PLL cells, while GLI1 knockdown suppresses BMP signal transduction, attenuating osteogenic differentiation in OPLL cells. Our findings highlight the significant role of the canonical Hedgehog signalling pathway and its interaction with the BMP pathway in the pathogenesis of OPLL.

USP39 phase separates into the nucleolus and drives lung adenocarcinoma progression by promoting GLI1 expression

BackgroundIntracellular membraneless organelles formed by liquid-liquid phase separation (LLPS) function in diverse physiological processes and have been linked to tumor-promoting properties. The nucleolus is one of the largest membraneless organelle formed through LLPS. Deubiquitylating enzymes (DUBs) emerge as novel therapeutic targets against human cancers. However, the nucleolar phase separation of DUBs and association with lung cancer development have remained incompletely investigated till now.MethodsGFP-USP39 fusion proteins were analyzed for LLPS properties using immunofluorescence, fluorescence recovery after photobleaching (FRAP) and in vitro LLPS assays. Intrinsically-disordered regions of USP39 were analyzed by PhaSepDB database. Transcriptomic profiling, Western blot, RT-PCR and luciferase reporter assays were conducted to identify targets regulated by USP39. The effects of USP39 depletion on tumor progression were tested using doxycycline-inducible USP39 knockdown and rescue lung adenocarcinoma cells both in vitro and in vivo by performing MTT, colony formation, EdU staining, transwell and tumor xenograft model experiments.ResultsUSP39 phase separates into nucleoli depending upon its N-terminal disordered region with amino acid residues 1-103. Lung cancer cell growth and migration were dramatically inhibited by USP39 knockdown, which was rescued by exogenous USP39 complementation. Moreover, knockdown of USP39 reduced oncogenic transcription effector GLI1 levels. Finally, USP39 downregulation restricted the formation of lung cancer xenografts in nude mice.ConclusionsUSP39 undergoes LLPS in the nucleolus and promotes tumor progression by regulating GLI1 expression. Downregulation of USP39 effectively suppressed lung cancer growth, and therefore targeting USP39 provides novel therapeutic strategy to treat lung cancer.

Oncogenic potential of truncated-Gli3 via the Gsk3β/Gli3/AR-V7 axis in castration-resistant prostate cancer.

The functional activation of the androgen receptor (AR) and its interplay with the aberrant Hh/Gli cascade are pivotal in the progression of castration-resistant prostate cancer (CRPC) and resistance to AR-targeted therapies. Our study unveiled a novel role of the truncated form of Gli (t-Gli3) in advancing CRPC. Investigation into Gli3 regulation revealed a Smo-independent mechanism for its activation. Despite lacking a transactivation domain, t-Gli3 relies on androgen receptor variant 7 (AR-V7) for its action. Mechanistically, Gsk3β activation led to the t-Gli3 generation, and inhibition of Gsk3β supported the accumulation of full-length Gli3 expression through a non-canonical mechanism. Knockdown of Gsk3β (Gsk3β KD) reduces CRPC cell proliferation, induces apoptosis via mitochondrial fragmentation, and triggers metabolomic reprogramming. The in vivo studies with Gsk3β KD cells in the mouse prostate resulted in tumor growth retardation compared to scramble cells. RNA-seq HALLMARK Gene Set Enrichment Analysis (GSEA) analysis of Gsk3β KD revealed a positive enrichment of apoptosis, tumor suppressor gene, and negative enrichment of oncogenic pathway. Furthermore, combinational use of a Gsk3β inhibitor with anti-Smo or Gli1 significantly inhibited the CRPC cell growth, which is resistant to individual Smo or Gli1 inhibitor targeting. Intriguingly, solely targeting Gli3 showed effectiveness in inhibiting CRPC cell growth. Overall, our study underscores the clinical significance of Gli3, emphasizing t-Gli3, and provides novel insights into the interplay of the Gsk3β/t-Gli3/AR-V7 axis in CRPC.

Counterregulatory roles of GLI2 and GLI3 in osteogenic differentiation via Gli1 expression.

The GLI1/GLI2/GLI3 transcription factors mediate Hedgehog (Hh) signaling, which is crucial for bone development. During intramembranous ossification, mesenchymal stem cells (MSCs) are directly differentiated into osteoblasts. Under basal and Hh pathway-stimulated conditions, primary cilia play essential roles in proteolytic processing of GLI3 to its repressor form (GLI3R), and in activation of GLI2. Although previous studies in mice suggested that Gli1 expression depends on GLI2 and GLI3, coordinated roles of GLI1, GLI2, and GLI3 in osteogenic differentiation are not fully understood at the cellular level. From the MSC line C3H10T1/2, we established Gli2-knockout (KO) and Gli3-KO cells, and constitutively GLI3R-producing (cGLI3R) cells, and expressed GLI1, GLI2, and GLI3 constructs in these cells. The results demonstrate at the cellular level that GLI2 and GLI3R counterregulate osteogenic differentiation via activating and repressing Gli1 expression, respectively; GLI3R, which results from GLI3 processing requiring protein kinase A-mediated phosphorylation, downregulates expression of Gli2 as well as Gli1; and GLI1 upregulates Gli1 itself and Gli2, constituting a GLI1-GLI2 positive feedback loop.

FOXA1 activates NOLC1 transcription through NOTCH pathway to promote cell stemness in lung adenocarcinoma.

Tumor cell stemness plays a pivotal role in generating functional heterogeneity within tumors and is implicated in essential processes such as drug resistance, metastasis, and cell proliferation. Therefore, creating novel tumor diagnostic techniques and therapeutic plans requires a knowledge of the possible processes that preserve the stem cell-like qualities of cancers. Bioinformatics analysis of NOLC1 expression in lung adenocarcinoma (LUAD) and prediction of its upstream transcription factors and their binding sites were completed. RT-qPCR detection of NOLC1 and FOXA1 expression, colony formation assay of cell proliferation, Transwell assay of cell invasion, sphere formation assay of cell stemness, western blot detection of CD133, OCT4, GLI1, NOTCH1 and Hes1 expression, CCK-8 assay of IC50 value of cisplatin, and ChIP and dual-luciferase reporter validation of binding relationship between NOLC1 and FOXA1 were done. NOLC1 expression was elevated in LUAD cells and tissues. Decreased NOLC1 expression inhibited the proliferation and invasive capacity of LUAD cells, prevented LUAD cells from becoming stem cells, and suppressed cisplatin resistance in the cells. Rescue tests demonstrated that NOLC1 activated the NOTCH pathway to increase the stemness of LUAD cells and promoted cisplatin resistance in LUAD cells. The activation of NOLC1 transcription by FOXA1 was validated by bioinformatics prediction and molecular verification, and the FOXA1/NOLC1 axis enhanced the stemness of LUAD cells. Activation of NOLC1 transcription by FOXA1 through NOTCH pathway promoted stemness of LUAD. FOXA1/NOLC1 axis is expected to become a new target for inhibiting stemness of LUAD cells.

Anti-Stemness and Anti-Proliferative Effects of Cadmium on Bovine Mammary Epithelial Cells.

Cadmium accumulation in the body can damage a variety of organs and impair their development and functions. In the present study, we investigated the effect of cadmium on the stemness and proliferation of normal bovine mammary epithelial cells (BMECs). Normal bovine mammary epithelial cells treated with cadmium chloride were assessed for the expression of stemness-related proteins and cell proliferation. Western blotting results found that exposure to different concentrations of cadmium (0, 1.25, 2.5, and 5 μm) for 48 h significantly increased Gli1 expression but unexpectedly decreased the expression of downstream stem cell-related proteins including BMI1, SOX2, and ALDH. However, we also observed that treatment with 5 μm cadmium for 48 h inhibited mammosphere formation using microscopy. In this study, cadmium exposure significantly reduced cell viability and mobility. Flow cytometry detection found that cadmium decreased the percentage of cells in the G0 phase but increased the percentage of cells in the S phase and the apoptosis rate. Furthermore, cadmium exposure significantly increased the levels of caspase-8, caspase-3, and PARP cleavage as assessed by western blotting. Our study uncovers a previously unrecognized role of cadmium in mammary cell stemness and suggests that cadmium may affect breast development by impairing normal stem cell self-renewal and inducing their apoptosis. Therefore, this study provides important scientific significance regarding whether heavy metal cadmium affects normal breast development.

Plasma Transcriptome Profile Associated with Chronic Kidney Disease Progression

Introduction: Understanding the molecular signals associated with the progression of kidney disease is vital for risk stratification and targeted treatment. Recent advances in RNA-sequencing technique have enabled us to characterize extracellular transcriptome profiles for precision diagnostics. Method: We evaluated the plasma mRNA profile of participants exhibiting slow (n = 119) and fast (n = 119) decline in estimated glomerular filtration rate (eGFR) among the Chronic Renal Insufficiency Cohort (CRIC) in a nested case control study. The two groups were matched for age, sex, race, baseline eGFR, proteinuria, and diabetes status. The next-generation sequencing data were analyzed using edgeR to identify differentially expressed genes (DEGs) and ingenuity pathway analysis was done to identify the associated pathways. We also compared the top plasma DEGs with gene expression in microdissected human chronic kidney disease (CKD) kidney. Results: We identified fragments from ∼28,000 annotated genes, of which 783 transcripts exhibited differential expression between slow and fast CKD progressors. Among 629 protein coding genes, 469 were overexpressed in slow progressors, while 157 showed increased expression in fast progressors. Expression of GLI2, CUX1, NOTCH1, and LRP1 transcripts were amplified in slow progressors. Pathway analysis linked these DEG to WNT/β-catenin signaling, IL-12 signaling and production in macrophages, Netrin-1 Signaling and Epithelial-Mesenchymal Transition pathways. Many of the plasma DEGs were also upregulated in microdissected human CKD kidney. Conclusion: Warranting further validation, circulating levels of aberrantly expressed transcripts hold potential to be used as biomarkers for fast CKD progression.

GLI3 Is Required for M2 Macrophage Polarization and M2-Mediated Waldenström Macroglobulinemia Growth and Survival.

Waldenstrom macroglobulinemia (WM) is a non-Hodgkin B-cell lymphoma, characterized by bone marrow infiltration with plasma cells and lymphocytes. The tumor microenvironment (TME) plays an important role in mediating WM cell biology, but the effects of macrophages on WM biology remains unclear. Here, we investigated the effects of macrophages on WM growth and survival and identified a novel role for transcription factor GLI3 in macrophage polarization. We found that co-culture of M0 and M2 macrophages promoted WM cell growth and survival, and co-culture WM cells with M0 macrophages induced M2-like phenotypes. Interestingly, GLI3 expression was induced in M2 macrophages (not M1), leading us to perform analysis of macrophages from mice lacking Gli3 in myeloid cells (M-Gli3-/- mice). A subset of differentially expressed genes implicated a role for GLI3 in macrophage polarization. Macrophages from M-Gli3-/- mice did not induce WM cell proliferation and reduced survival compared to M2 macrophages from WT mice. In addition, in vitro polarization of M0 macrophages from M-Gli3-/- was not able to induce M2 markers such as CD163, despite inducing iNos expression (M1 marker). Taken together, these results suggest a role for M2 macrophages in promoting WM cell growth and identify GLI3 as a modulator of macrophage polarization.

YAP1 modulation of primary cilia-mediated ciliogenesis in 2D and 3D prostate cancer models.

The primary cilium, a non-motile organelle present in most human cells, plays a crucial role in detecting microenvironmental changes and regulating intracellular signaling. Its dysfunction is linked to various diseases, including cancer. We explored the role of ciliated cells in prostate cancer by using Gefitinib and Jasplakinolide compounds to induce ciliated cells in both normal and tumor-like prostate cell lines. We assessed GLI1 and IFT20 expression and investigated YAP1 protein's role, which is implicated in primary cilium regulation. Finally, we examined these compounds in 3D cell models, aiming to simulate in vivo conditions. Our study highlights YAP1 as a potential target for novel genetic models to understand the primary cilium's role in mediating resistance to anticancer treatments.

POU3F4 up-regulates Gli1 expression and promotes neuronal differentiation and synaptic development of hippocampal neural stem cells

BackgroundNeural stem cells (NSCs) are considered to be the most promising cell type for cell replacement therapy in neurodegenerative diseases. However, their low neuronal differentiation ratio impedes their application in such conditions. Elucidating the molecular mechanism of NSC differentiation may provide the necessary experimental basis for expanding their application. Previous studies have indicated that POU3F4 can induce neuronal differentiation of NSCs, this study aims to underly the possible exact mechanism of POU3F4 on the NSC differentiation and development.MethodsNSCs were isolated and cultured from the hippocampus of neonatal mice. The frozen hippocampal sections were prepared for immunohistochemical staining. Synaptic development was assessed using electron microscopy. High-throughput sequencing was employed to analyze the gene expression profile following the overexpression of Brn4. Gene expression levels were determined through Western blotting and qRT-PCR. Cell cycle and differentiation were evaluated using flow cytometry and immunofluorescent staining.ResultsIt was found that POU3F4 promoted the neuronal differentiation of hippocampal NSCs and synapse development, and inhibited NSC proliferation. POU3F4-deficient mice exhibited impairments in learning and memory. RNA sequencing and ChIP assays confirmed that Gli1 was downstream of POU3F4. Loss and gain function experiments indicated that Gli1 mediated POU3F4 promoting neuronal differentiation and synapse development. Forced expression of Gli1 in hippocampus improved learning and memory function of animal models.ConclusionsThe results suggest that POU3F4 and Gli1 promote neuronal differentiation and synaptic development of NSCs, and that Gli1 partially mediates the effects of POU3F4.Graphical abstract

Astragalus polysaccharide ameliorates diabetic retinopathy by inhibiting the SHH-Gli1-AQP1 signaling pathway in streptozotocin-induced type 2 diabetic rats.

This study aims to investigate the effects of astragalus polysaccharide (APS) on diabetic retinopathy through the SHH-Gli1-AQP1 pathway. The anti-type 2 diabetes mellitus (T2DM) targets of APS were identified through comprehensive searches of drug and disease-related databases. A protein-protein interaction network was then constructed, followed by GO and KEGG enrichment analyses. Molecular docking simulations were performed to evaluate the interactions of APS and metformin with Gli1 and AQP1. An in vivo T2DM rat model was established via streptozotocin (STZ) injection and treated with metformin and varying doses of APS for 12 weeks. Histological changes in retinal cells were assessed using H&E and PAS staining. The expression levels of AQP1, Gli1, and SHH in the retina were measured using immunohistochemistry, Western blotting, immunofluorescence, and ELISA. Additionally, mRNA expression of AQP1, Gli1, and SHH was quantified by RT-qPCR. Bioinformatic analyses indicated that Gli1 and AQP1, key components of the SHH-Gli1- AQP1 signaling pathway, may be associated with T2DM. Subsequent experiments demonstrated that the STZ-induced T2DM rats exhibited significant retinal damage, which was notably mitigated by both APS and metformin treatments. Furthermore, the SHH-Gli1-AQP1 signaling pathway was found to be overactivated in STZ-induced T2DM rats. Treatment with APS and metformin significantly reduced the elevated expression levels of SHH, Gli1, and AQP1. APS effectively inhibits retinal damage of STZ-induced T2DM rats by restraining the SHH-Gli1-AQP1 signaling pathway.

7-Ketocholesterol Effects on Osteogenic Differentiation of Adipose Tissue-Derived Mesenchymal Stem Cells.

Some oxysterols were shown to promote osteogenic differentiation of mesenchymal stem cells (MSCs). Little is known about the effects of 7-ketocholesterol (7-KC) in this process. We describe its impact on human adipose tissue-derived MSC (ATMSC) osteogenic differentiation. ATMSCs were incubated with 7-KC in osteogenic or adipogenic media. Osteogenic and adipogenic differentiation was evaluated by Alizarin red and Oil Red O staining, respectively. Osteogenic (ALPL, RUNX2, BGLAP) and adipogenic markers (PPARƔ, C/EBPα) were determined by RT-PCR. Differentiation signaling pathways (SHh, Smo, Gli-3, β-catenin) were determined by indirect immunofluorescence. ATMSCs treated with 7-KC in osteogenic media stained positively for Alizarin Red. 7-KC in adipogenic media decreased the number of adipocytes. 7-KC increased ALPL and RUNX2 but not BGLAP expressions. 7-KC decreased expression of PPARƔ and C/EBPα, did not change SHh, Smo, and Gli-3 expression, and increased the expression of β-catenin. In conclusion, 7-KC favors osteogenic differentiation of ATMSCs through the expression of early osteogenic genes (matrix maturation phase) by activating the Wnt/β-catenin signaling pathway, while inhibiting adipogenic differentiation. This knowledge can be potentially useful in regenerative medicine, in treatments for bone diseases.

Investigation of FF-MAS oxysterole’s role in follicular development and its relation to hedgehog signal pathway

The Hedgehog signaling pathway plays a crucial role in folliculogenesis; however, the association between FF-MAS oxysterol activity in folliculogenesis and the Hedgehog signaling pathway has not been revealed. The evaluation of FF-MAS activity in polycystic ovary syndrome (PCOS) with folliculogenesis disorder might provide a new approach to tackle follicular and oocyte maturation failure. The question is: does FF-MAS oxysterol affect granulosa cell (GC) proliferation? If so, is this effect facilitated through the Hedgehog pathway? To answer these questions, GCs were isolated from follicle fluids obtained from patients undergoing oocyte retrieval during in vitro fertilization (IVF) treatment. After the isolated GCs were incubated in different cell culture media, the levels of Hedgehog pathway components (SMO, Gli1) were measured by using immunohistochemical methods, cytoELISA, and qRT-PCR. Meanwhile, cell proliferation rates were determined. Significant increases (p < 0.001) in SMO and Gli1 expressions and cell proliferation were observed in the FF-MAS-treated subgroups of both PCOS and male factor participants compared to the FF-MAS deficient subgroup. Remarkably, FF-MAS positively affected the pathway components despite the pathway inhibitor cyclopamine. Although the increase in Hedgehog pathway components was slightly higher in the male factor group (MF), it was not statistically significant. In our study, we demonstrated for the first time the molecular effect of FF-MAS on human GCs in folliculogenesis. Since FF-MAS is already used in assisted reproductive techniques in animals and is known to be synthesized in the human body, it could be considered a new approach in human IVF treatments.

Mutual Amplification of GLI2/Hedgehog and Transcription Factor JUN/AP-1 Signaling in Fibroblasts in Systemic Sclerosis: Potential Implications for Combined Therapies.

Deregulation of the cJUN/AP-1 and hedgehog/GLI2 signaling pathways has been implicated in fibroblast activation in systemic sclerosis (SSc). However, the consequences of their concomitant up-regulation are unknown. Here, we tested the hypothesis that mutual amplification of both pathways might drive persistent fibroblast activation. Cultured fibroblasts and skin sections of patients with diffuse SSc and healthy volunteers were analyzed. cJUN/AP-1 signaling and hedgehog/GLI2 signaling were inhibited using knockdown and pharmacologic approaches. Hedgehog signaling was activated in mice by fibroblast-specific overexpression of constitutively active Smoothened. cJUN and GLI2 are concomitantly up-regulated and colocalize in fibroblasts of patients with SSc compared to healthy controls. Activation of hedgehog/GLI2 signaling induces the expression of cJUN in vitro and in vivo, whereas inactivation of GLI2 inhibits cJUN expression. Likewise, inactivation of cJUN impairs the expression of GLI2. This mutual regulation occurs at the level of transcription with binding of cJUN and GLI2 to specific binding motifs. Interference with this mutual amplification of cJUN signaling and GLI2 signaling inhibits fibroblast activation and collagen release: Inhibition of cJUN/AP-1 signaling ameliorates hedgehog-induced fibroblast activation and skin fibrosis in SmoACT mice with a reduction of skin thickness of 103% (P = 0.0043) in the treatment group compared to the fibrotic control group. Moreover, combined pharmacologic inhibition of cJUN/AP-1 and hedgehog/GLI2 exerts additive antifibrotic effects in a model of TGFβ-driven experimental fibrosis (TBRACT mice). The transcription factors cJUN and GLI2 reinforce each other's activity to promote fibroblast activation in SSc. Interruption of this crosstalk by combined inhibition of both pathways exerts additive antifibrotic effects at well-tolerated doses.

Abstract B022: Tumoral GLI1 controls the resident innate and adaptive tumor immune microenvironment in triple negative breast cancer

Abstract Background: Triple-negative breast cancer (TNBC) accounts for 15-20% of breast cancer (BC) cases but due to its aggressive nature and the lack of targeted treatment options, represents a disproportionately higher number of BC-related deaths. Compared to other BC subtypes, TNBCs are more inflamed with M2-like tumor-associated macrophages (TAMs) and cytotoxic T-lymphocytes (CTLs) which are associated with poor and good prognosis, respectively. Clinical trials have proven that immunogenic cancers can be effectively treated through immune checkpoint blockade (ICB), a treatment strategy that prevents cancer cells from silencing CTL-mediated attack. However, CTLs can be suppressed by M2-like TAMs which can limit ICB efficacy and support tumor growth. The hedgehog (HH) signaling pathway is highly activated in TNBC and higher expression of GLI1 is associated with worse overall survival. Recent pan-cancer analyses highlight a significant correlation between activated HH signaling and characteristics of immune evasion. We aim to clarify how activated HH signaling regulates resident innate and adaptive immune cells in the tumor microenvironment (TME) in TNBC. Methods: Primary K14-cre; Brca1 fl/fl ; P53 fl/fl (KBP) murine TNBC cells were transfected with CRISPR/Cas9 + sgRNA targeting GLI1. After isolating single cell clones and confirming GLI1 knockout (KO), KBP and KBP-GLI1-KO cells were orthotopically injected into the mammary fat pad of syngeneic immune-competent female mice and allowed to grow for 6-8 weeks. Tumor volume was measured once tumors were palpable, and tumors were harvested once the largest tumor reached ethical endpoint. Tumors were weighed at harvest and fluorescence activated cell sorting (FACS) was performed to determine if there was an effect on the composition of immune populations. Results: At harvest, KBP-GLI1-KO tumors were delayed in growth and significantly smaller than KBP tumors. FACS analysis showed that GLI1-KO tumors had increased CD4+ and CD8+ T cells and a reduced amount of Foxp3+ CD4+ Tregs. Furthermore, GLI1-KO tumors had significantly fewer F4/80+ CD11b+ TAMs within the TME. Amongst TAM populations, there was reduced CD206+ M2-like TAMs and an increase in CD80+ M1-like TAMs upon loss of GLI1. Similar trends were observed when KBP allografts were treated with the GLI1 inhibitor, GANT61. Immunohistochemical and RNAseq analysis are ongoing. Similar experiments with other KBP-GLI1-KO clones are currently being done. Conclusion: Here, we show that tumoral GLI1 not only promotes tumor growth, but also supports an immunosuppressive TME in TNBC. Abolishing GLI1 converted tumors to a pro-inflammatory phenotype marked by an increase in CD4+ and CD8+ T cells and a reduction in CD206+ M2-like TAMs. Future experiments are aimed at revealing the mechanisms by which GLI1 regulates immune cell recruitment to the TME and testing the effect of combination immunotherapy. Overall, these preliminary findings identify GLI1 as a potential therapeutic target to limit tumor growth and promote anti-tumor immunity. Citation Format: Aidan J Gray, Wanda Marini, Kiichi Murakami, Michael Reedijk. Tumoral GLI1 controls the resident innate and adaptive tumor immune microenvironment in triple negative breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2024 Oct 18-21; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2024;12(10 Suppl):Abstract nr B022.

MiR-200c targeting GLI3 inhibits cell proliferation and promotes apoptosis in non-small cell lung cancer cells.

Lung cancer is a common malignant tumor with low cure rate. It has an easy recurrence and metastasis. This study explored whether miR-200c could regulate the biological behavior of non-small cell lung cancer cells through targeting GLI3. Luciferase reporter gene analysis was used to verify the interaction between miR-200c-3p and GLI3. miR-200c-3p and GLI3 were transiently overexpressed into A549 cells. The cell viability rate was detected by cell counting kit-8, cell invasion ability was detected with Transwell, cell apoptosis and cell cycle was determined by flow cytometry, and the expression of GLI3 was detected using quantitative polymerase chain reaction and Western blot, to verify the effect of the interaction between miR-200c-3p and GLI3 on the cell activities. miR-200c-3p overexpression could inhibit cell viability and invasion, promote apoptosis, induce G0/G1 arrest, and inhibit cell division. GLI3 overexpression could reverse the miR-200c-3p inhibition on cell cycle, reduce the number of cells in the G0/G1 phase and increase the number of cells in the S phase. miR-200c-3p overexpression in A549 cells could inhibit cell viability and invasion, and promote apoptosis. miR-200c-3p could target GLI3 to regulate cell cycle and inhibit cell proliferation.

Mapping the intricacies of GLI1 in hedgehog signaling: A combined bioinformatics and clinical analysis in Head & Neck cancer in Western India

BackgroundActivation of various cancer stem cell pathways are thought to be responsible for treatment failure and loco-regional recurrence in Head and Neck cancer. Hedgehog signaling, a major cancer stem signaling pathway plays a major role in relapse of disease. GLI1, a transcription activator, plays an important role in canonical/non-canonical activation of Hedgehog signaling. MethodsData for H&N cancer patients were collected from The Cancer Genome Atlas- H&N Cancer (TCGA-HNSC). GLI1 co-expressed genes in TCGA-HNSC were then identified using cBioPortal and subjected to KEGG pathway analysis by DAVID tool. Network Analyzer and GeneMania plugins from CytoScape were used to identify hub genes and predict a probable pathway from the identified hub genes respectively. To confirm the hypothesis, real-time gene expression was carried out in 75 patients of head and neck cancer. ResultsSignificantly higher GLI1 expression was observed in tumor tissues of H&N cancer and it also showed worst overall survival. Using cBioPortal tool, 2345 genes were identified that were significantly co-expressed with GLI1. From which, 15 hub genes were identified through the Network Analyzer plugin in CytoScape. A probable pathway prediction based on hub genes showed the interconnected molecular mechanism and its role in non-canonical activation of Hedgehog pathway by altering the GLI1 activity. The expressions of SHH, GLI1 and AKT1 were significant with each other and were found to be significantly associated with Age, Lymph-Node status and Keratin. ConclusionThe study emphasizes the critical role of the Hh pathway's activation modes in H&N cancer, particularly highlighting the non-canonical activation through GLI1 and AKT1. The identification of SHH, GLI1 and AKT1 as potential diagnostic biomarkers and their association with clinic-pathological parameters underscores their relevance in prognostication and treatment planning. Hh pathway activation through GLI1 and its cross-talk with various pathways opens up the possibility of newer treatment strategies and developing a panel of therapeutic targets in H&N cancer patients.

Examination of piperonyl butoxide developmental toxicity as a Sonic hedgehog pathway inhibitor targeting limb and palate morphogenesis

Piperonyl butoxide (PBO) is a pesticide synergist with widespread use and human exposure that was discovered to inhibit Sonic hedgehog (Shh) signaling, a pathway required for numerous developmental processes. Previous examinations of PBO’s potential for developmental toxicity have generated seemingly conflicting results. We investigated the impact of acute PBO exposure targeting Shh pathway activity during palate and limb morphogenesis. Timed-pregnant C57BL/6 J mice were exposed to a single PBO dose (67–1800 mg/kg) at gestational day (GD) 9.75, and litters were collected at GD10.25 and GD10.75 to examine Shh pathway activity or GD17 for phenotypic assessment. PBO exposure induced dose-dependent limb malformations and cleft palate in the highest dose group. Following PBO exposure, reduced expression of the Shh pathway activity markers Gli1 and Ptch1 was observed in the embryonic limb buds and craniofacial processes. These findings provide additional evidence that prenatal PBO exposure targeting Shh pathway activity can result in malformations in mice that parallel common etiologically complex human birth defects.

MiR-875-5p suppresses Gli1 to alter the hedgehog signaling pathway, which in turn has hepatocellular cancer-related tumor suppressing properties

BackgroundOne of the most prevalent cancers worldwide is HCC, which has put patient health at risk. Increasing evidence indicated that messenger RNAs (mRNAs) played significant roles in modulating tumorigenesis. It has been established that Gli1 acts as an oncogene in a number of malignancies. However, more research was necessary to understand the Gli1 regulation mechanism in HCC. MethodsMicroarray technology was used to evaluate the expression of mRNAs. RT-qPCR was utilized to evaluate Gli1 and miR-875-5p expression. To investigate the role of Gli1, tests using CCK-8, EdU, transwell, immunofluorescence, and Western blot analysis was performed. RIP, RNA pull down, and luciferase reporter assays were employed to verify the interaction between Gli1 and miR-875-5p. ResultsIn tissues and cells of HCC, Gli1 expression appeared to be upregulated, especially in metastatic samples and advanced stages of the disease. A worse outcome was predicted by elevated Gli1 expression. Additionally, in HCC, Gli1 inhibition impeded the growth, migration, and development of the EMT. Since miR-875-5p was shown to have a molecular target in Gli1, miR-875-5p mediated the negative regulation of Gli1. In HCC tissues, its expression pattern was less prominent. In HCC tissues, there was an inverse relationship between Gli1 expression and miR-875-5p expression. Overexpressing Gli1 helped to partially counteract the suppression of HCC migration, proliferation, and EMT formation by miR-875-5p overexpression. ConclusionsMiR-875-5p in HCC suppresses tumors by downregulating Gli1, which supplies a novel treatment for HCC patients.