gant-61 and Lung-Neoplasms

Despite the huge efforts employed to implement novel chemotherapeutic paradigms for lung cancer, the disease still remains a major concern worldwide. Targeting molecular pathways as Hedgehog (Hh) and Mitogen-activated protein kinase (MAPK) represent a new hope in lung cancer treatment. This work was undertaken to evaluate the antitumor effects of GANT61 (5 μM), BI-847325(30 μM), and GANT61 (5 μM)/BI-847325(30 μM) combination on A549 adenocarcinoma lung cancer cell line. The growth inhibition 50 (GI50) for both drugs was performed using MTT. The protein levels of Caspase-3, Bcl-2-associated X protein (Bax), Myeloid cell leukemia sequence 1 (MCL-1), cyclin D1, vascular endothelial growth factor (VEGF), extracellular signal-regulated kinases (ERK), p-Akt, and phosphohistone H3 (pHH3) were measured using ELISA. Glioma-associated oncogene homolog 1(Gli1) gene expression was assessed by quantitative real-time PCR. The GI50 for GANT61 and BI-8473255 were 5 µM and 30 µM, respectively. Caspase-3 and Bax protein levels were significantly elevated while MCL-1, cyclin D1, VEGF, ERK 1/2, p-Akt, and pHH3 levels were significantly reduced by both drugs and their combination relative to the control group. Gli1 gene expression was down-regulated in all groups relative to the control group. GANT61, BI-847325 and their combination inhibited proliferation and angiogenesis but activated the apoptotic pathway. Both drugs conferred a profound negative impact on the crosstalk between each of Hh and MAPK pathways and Phosphoinositide 3 -kinases (PI3K)/Akt/Mammalian target of Rapamycin (mTOR). To the best of our knowledge, the antitumor effects of BI-847325/GANT61 combination have not been tested before. Further in-vitro and in-vivo studies are warranted to support the findings.

Topics: Aniline Compounds; Apoptosis; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Hedgehog Proteins; Humans; Indoles; Lung Neoplasms; Myeloid Cell Leukemia Sequence 1 Protein; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Pyridines; Pyrimidines; Signal Transduction; Vascular Endothelial Growth Factor A; Zinc Finger Protein GLI1

We previously demonstrated that proline-rich protein 11 (PRR11) and spindle and kinetochore associated 2 (SKA2) constituted a head-to-head gene pair driven by a prototypical bidirectional promoter. This gene pair synergistically promoted the development of non-small cell lung cancer. However, the signaling pathways leading to the ectopic expression of this gene pair remains obscure. In the present study, we first analyzed the lung squamous cell carcinoma (LSCC) relevant RNA sequencing data from The Cancer Genome Atlas (TCGA) database using the correlation analysis of gene expression and gene set enrichment analysis (GSEA), which revealed that the PRR11-SKA2 correlated gene list highly resembled the Hedgehog (Hh) pathway activation-related gene set. Subsequently, GLI1/2 inhibitor GANT-61 or GLI1/2-siRNA inhibited the Hh pathway of LSCC cells, concomitantly decreasing the expression levels of PRR11 and SKA2. Furthermore, the mRNA expression profile of LSCC cells treated with GANT-61 was detected using RNA sequencing, displaying 397 differentially expressed genes (203 upregulated genes and 194 downregulated genes). Out of them, one gene set, including BIRC5, NCAPG, CCNB2, and BUB1, was involved in cell division and interacted with both PRR11 and SKA2. These genes were verified as the downregulated genes via RT-PCR and their high expression significantly correlated with the shorter overall survival of LSCC patients. Taken together, our results indicate that GLI1/2 mediates the expression of the PRR11-SKA2-centric gene set that serves as an unfavorable prognostic indicator for LSCC patients, potentializing new combinatorial diagnostic and therapeutic strategies in LSCC.

Topics: Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Chromosomal Proteins, Non-Histone; Datasets as Topic; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Hedgehog Proteins; Humans; Kaplan-Meier Estimate; Lung; Lung Neoplasms; Nuclear Proteins; Prognosis; Proteins; Pyridines; Pyrimidines; RNA-Seq; RNA, Small Interfering; Signal Transduction; Transcriptional Activation; Zinc Finger Protein GLI1; Zinc Finger Protein Gli2

Resistance to chemotherapeutic agents is the main cause of reduced survival in non-small cell lung cancer (NSCLC) patients. The Hedgehog (HH) pathway has been shown to be crucial in cell development and survival. Activated in several types of cancer it might be a potent bypass mechanism mediating chemotherapy resistance.. HCC827 NSCLC cells were treated with sub-lethal doses of pemetrexed to produce pemetrexed resistance. RT-qPCR was performed to measure gene expression of HH pathway proteins. A cell growth assay was used to measure the impact of the HH-inhibitor Gant61 in naïve and chemoresistant cell lines.. Pemetrexed resistant cells showed significantly increased expression of HH signaling genes (GLI1, GLI2, GLI3, PTCH1, SHH). Supporting these results, pemetrexed resistant cells treated with the HH inhibitor Gant61 showed reduced proliferation compared to naïve cells.. HH pathway may play an important role in mediating pemetrexed resistance in NSCLC cells. Blocking the HH pathway may be a potential option to overcome this resistance.

Topics: Antineoplastic Agents; Carcinoma, Non-Small-Cell Lung; Cell Growth Processes; Cell Line, Tumor; Drug Resistance, Neoplasm; Gene Expression; Hedgehog Proteins; Humans; Lung Neoplasms; Pemetrexed; Pyridines; Pyrimidines; Signal Transduction

Aberrant Hedgehog/GLI signaling has been implicated in a diverse spectrum of human cancers, but its role in lung adenocarcinoma (LAC) is still under debate. We show that the downstream effector of the Hedgehog pathway, GLI1, is expressed in 76% of LACs, but in roughly half of these tumors, the canonical pathway activator, Smoothened, is expressed at low levels, possibly owing to epigenetic silencing. In LAC cells including the cancer stem cell compartment, we show that GLI1 is activated noncanonically by MAPK/ERK signaling. Different mechanisms can trigger the MAPK/ERK/GLI1 cascade including KRAS mutation and stimulation of NRP2 by VEGF produced by the cancer cells themselves in an autocrine loop or by stromal cells as paracrine cross talk. Suppression of GLI1, by silencing or drug-mediated, inhibits LAC cells proliferation, attenuates their stemness and increases their susceptibility to apoptosis in vitro and in vivo. These findings provide insight into the growth of LACs and point to GLI1 as a downstream effector for oncogenic pathways. Thus, strategies involving direct inhibition of GLI1 may be useful in the treatment of LACs.

Topics: Adenocarcinoma; Animals; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Female; Humans; Lung Neoplasms; Mice; Mice, SCID; Mitogen-Activated Protein Kinase Kinases; Neoplastic Stem Cells; Neuropilin-2; Proto-Oncogene Proteins p21(ras); Pyridines; Pyrimidines; RNA Interference; RNA, Small Interfering; Xenograft Model Antitumor Assays; Zinc Finger Protein GLI1

Gli transcription factors of the Hedgehog (Hh) pathway have been reported to be drivers of malignant mesothelioma (MMe) cell survival. The Gli inhibitor GANT61 induces apoptosis in various cancer cell models, and has been associated directly with Gli inhibition. However various chemotherapeutics can induce cell death through generation of reactive oxygen species (ROS) but whether ROS mediates GANT61-induced apoptosis is unknown. In this study human MMe cells were treated with GANT61 and the mechanisms regulating cell death investigated. Exposure of MMe cells to GANT61 led to G1 phase arrest and apoptosis, which involved ROS but not its purported targets, GLI1 or GLI2. GANT61 triggered ROS generation and quenching of ROS protected MMe cells from GANT61-induced apoptosis. Furthermore, we demonstrated that mitochondria are important in mediating GANT61 effects: (1) ROS production and apoptosis were blocked by mitochondrial inhibitor rotenone; (2) GANT61 promoted superoxide formation in mitochondria; and (3) mitochondrial DNA-deficient LO68 cells failed to induce superoxide, and were more resistant to apoptosis induced by GANT61 than wild-type cells. Our data demonstrate for the first time that GANT61 induces apoptosis by promoting mitochondrial superoxide generation independent of Gli inhibition, and highlights the therapeutic potential of mitochondrial ROS-mediated anticancer drugs in MMe.

Topics: Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; G1 Phase; HCT116 Cells; HT29 Cells; Humans; Lung Neoplasms; Mesothelioma; Mesothelioma, Malignant; Mitochondria; Oxidative Stress; Pyridines; Pyrimidines; Reactive Oxygen Species; Transcription Factors; Zinc Finger Protein GLI1

The present study sought to determine whether the Hedgehog (Hh) pathway is active and regulates the cell growth of cultured malignant pleural mesothelioma (MPM) cells and to evaluate the efficacy of pathway blockade using smoothened (SMO) antagonists (SMO inhibitor GDC-0449 or the antifungal drug itraconazole [ITRA]) or Gli inhibitors (GANT61 or the antileukemia drug arsenic trioxide [ATO]) in suppressing MPM viability.. Selective knockdown of SMO to inhibit Hh signaling was achieved by small interfering RNA in 3 representative MPM cells. The growth inhibitory effect of GDC-0449, ITRA, GANT61, and ATO was evaluated in 8 MPM lines, with cell viability quantified using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell death was determined by annexinV/propidium iodide staining and flow cytometry.. SMO small interfering RNA mediated a two- to more than fivefold reduction of SMO and Gli1 gene expression as determined by real-time quantitative reverse-transcriptase polymerase chain reaction, indicating significant Hh pathway blockade. This was associated with significantly reduced cell viability (34% ± 7% to 61% ± 14% of nontarget small interfering RNA controls; P = .0024 to P = .043). Treating MPM cells with Hh inhibitors resulted in a 1.5- to 4-fold reduction of Gli1 expression. These 4 Hh antagonists strongly suppressed MPM cell viability. More importantly, ITRA, ATO, GANT61 induced significant apoptosis in the representative MPM cells.. Hh signaling is active in MPM and regulates cell viability. ATO and ITRA were as effective as the prototypic SMO inhibitor GDC-0449 and the Gli inhibitor GANT61 in suppressing Hh signaling in MPM cells. Pharmaceutical agents Food and Drug Administration-approved for other indications but recently found to have anti-Hh activity, such as ATO or ITRA, could be repurposed to treat MPM.

Topics: Anilides; Antineoplastic Agents; Apoptosis; Arsenic Trioxide; Arsenicals; Cell Line, Tumor; Cell Proliferation; Cell Survival; Dose-Response Relationship, Drug; Gene Expression Regulation, Neoplastic; Hedgehog Proteins; Humans; Itraconazole; Lung Neoplasms; Mesothelioma; Mesothelioma, Malignant; Molecular Targeted Therapy; Oxides; Pleural Neoplasms; Pyridines; Pyrimidines; Receptors, G-Protein-Coupled; RNA Interference; Signal Transduction; Smoothened Receptor; Time Factors; Transcription Factors; Transfection; Zinc Finger Protein GLI1

Lung squamous cell carcinoma (LSCC) currently lacks effective targeted therapies. Previous studies reported overexpression of Hedgehog (HH)-GLI signaling components in LSCC. However, they addressed neither the tumor heterogeneity nor the requirement for HH-GLI signaling. Here, we investigated the role of HH-GLI signaling in LSCC, and studied the therapeutic potential of HH-GLI suppression.. Gene expression datasets of two independent LSCC patient cohorts were analyzed to study the activation of HH-GLI signaling. Four human LSCC cell lines were examined for HH-GLI signaling components. Cell proliferation and apoptosis were assayed in these cells after blocking the HH-GLI pathway by lentiviral-shRNA knockdown or small-molecule inhibitors. Xenografts in immunodeficient mice were used to determine the in vivo efficacy of GLI inhibitor GANT61.. In both cohorts, activation of HH-GLI signaling was significantly associated with the classical subtype of LSCC. In cell lines, genetic knockdown of Smoothened (SMO) produced minor effects on cell survival, whereas GLI2 knockdown significantly reduced proliferation and induced extensive apoptosis. Consistently, the SMO inhibitor GDC-0449 resulted in limited cytotoxicity in LSCC cells, whereas the GLI inhibitor GANT61 was very effective. Importantly, GANT61 demonstrated specific in vivo antitumor activity in xenograft models of GLI(+) cell lines.. Our studies demonstrate an important role for GLI2 in LSCC, and suggest GLI inhibition as a novel and potent strategy to treat a subset of patients with LSCC.

Topics: Animals; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Gene Knockdown Techniques; Hedgehog Proteins; Heterografts; Humans; Lung Neoplasms; Mice; Pyridines; Pyrimidines; Receptors, G-Protein-Coupled; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Smoothened Receptor; Transcription Factors; Zinc Finger Protein GLI1