hes1-protein--human and Lung-Neoplasms

Various studies have assessed the clinicopathological and prognostic value of Notch1 and Notch3 expression in Non-small cell lung cancer (NSCLC), but their results remain controversial. This meta-analysis was conducted to address the above issues by using a total of 19 studies involving 3663 patients. The correlations between Notch1 and Notch3 expression and clinicopathological features and NSCLC prognosis were analyzed. The meta-analysis indicated that higher expression of Notch1 was associated with greater possibility of lymph node metastasis and higher TNM stages. Moreover, patients with Notch1 overexpression and Notch3 overexpression showed significantly poor overall survival (Notch1: HR, 1.29; 95% CI, 1.06-1.57, p = 0.468 and I(2) = 0.0%; Notch3: HR, 1.57; 95%CI, 1.04-2.36, p = 0.445 and I(2) = 0.0%). Furthermore, there are statistically significant association between overall survival of NSCLC patients and the expression of Notch signaling ligand DLL3 and target gene HES1. Our meta-analysis supports that Notch signaling is a valuable bio-marker to predict progression and targeting Notch signaling could benefit subpopulation of NSCLC patients.

Topics: Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Carcinoma, Non-Small-Cell Lung; Databases, Factual; Disease Progression; Homeodomain Proteins; Humans; Intracellular Signaling Peptides and Proteins; Lung Neoplasms; Lymphatic Metastasis; Membrane Proteins; Neoplasm Staging; Prognosis; Proportional Hazards Models; Receptor, Notch1; Receptor, Notch3; Receptors, Notch; Signal Transduction; Survival Rate; Transcription Factor HES-1

Resistance to epidermal growth factor tyrosine kinase inhibitors (EGFR-TKI) remains one of the major challenges in lung adenocarcinoma (LUAD) therapy. Here, we find an increased frequency of the L12_16 amino acid deletion mutation in the signal peptide region of NOTCH4 (NOTCH4

Topics: Adenocarcinoma of Lung; Cell Line, Tumor; Down-Regulation; Drug Resistance, Neoplasm; ErbB Receptors; Humans; Lung Neoplasms; Mutation; Protein Kinase Inhibitors; Receptor, Notch4; Transcription Factor HES-1

The Notch signaling pathway has different roles in many human neoplasms, being either tumor-promoting or anti-proliferative. In addition, Notch signaling in carcinogenesis can be tissue dependent. The aim of the current study is to elucidate the relation between Notch1 protein expression in lung cancer cells and the following Notch related proteins: Hes1, c-Myc, Jagged1 and Jagged2.. Notch1 and its related proteins were detected in human lung cancer cell lines and in 54 surgically resected different lung carcinoma tissues. Then, we used small interfering RNA (siRNA) technology, to down-regulate the expression of Notch1 in H69AR and SBC3 small cell lung carcinoma (SCLC) cells. Also, we transfected venus Notch1 intracellular domain (v.NICD) plasmid into human SCLC lines; H69.. The expression of Hes1, c-Myc and Jagged2 is affected by Notch1 in SCLC.. There is a strong association between the expression of Notch1 protein and the expression of Hes1, c-Myc and Jagged2 proteins, which could aid in better understanding tumorigenesis in SCLC.

Topics: A549 Cells; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Humans; Jagged-1 Protein; Jagged-2 Protein; Lung Neoplasms; Proto-Oncogene Proteins c-myc; Receptor, Notch1; Receptors, Notch; RNA, Small Interfering; Signal Transduction; Small Cell Lung Carcinoma; Transcription Factor HES-1

Our study aimed to investigate the function of GALNT2 in lung adenocarcinoma (LUAD).. We used network tools and tissue microarray immunohistochemistry to measure the expression levels of GALNT2 in LUAD. Kaplan-Meier curves and Cox regression methods were used in survival analysis. We detected the role of GALNT2 in cell lines by Cell Counting Kit-8, colony formation, transwell, and wound healing assays. We performed Western blotting to evaluate downstream protein levels.. GALNT2 was highly expressed in LUAD samples and indicated a poor prognosis. Knockdown of GALNT2 suppressed cell line proliferation, migration, and invasion abilities, while overexpression of GALNT2 enhanced those phenotypes. Moreover, GALNT2 activated Notch/Hes1-PTEN-PI3K/Akt signaling axis.. Our data confirmed the cancer-promoting effect of GALNT2, and might provide a new approach for LUAD therapy.

Topics: Adenocarcinoma of Lung; Aged; Apoptosis; Biomarkers, Tumor; Cell Movement; Cell Proliferation; Female; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Male; N-Acetylgalactosaminyltransferases; Neoplasm Invasiveness; Phosphatidylinositol 3-Kinases; Polypeptide N-acetylgalactosaminyltransferase; Prognosis; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Receptor, Notch1; Survival Rate; Transcription Factor HES-1; Tumor Cells, Cultured

The aim was to analyse the tumor expression of Notch1, Hes1, Ascl1, and DLL3 in Small-Cell Lung Cancer (SCLC) and each such biomarker's potential association with clinical characteristics and prognosis after platinum-doublet chemotherapy (PDCT).. The protein expression of the biomarkers was evaluated using immunohistochemistry. Patients were categorized according to their sensitivity to first line PDCT: with a Progression-free survival (PFS) ≥ 3 months after completion of treatment considered "sensitive" and < 3 months after completion of treatment considered "refractory". PFS and overall survival were computed using Kaplan-Meier curves with 95% confidence interval.. The study included 46 patients, with 21 and 25 of the patients having "sensitive" and "refractory" disease, respectively. The majority of patients had a high DLL3 expression (n = 38), while a minority had Notch 1-high expression (n = 10). The chi-square test showed that there was a statistically significant negative association between Notch1 and Ascl1 expression (p = 0.013). The overall survival for patients with Notch1- high vs. low expression was 8.1 vs. 12.4 months, respectively (p = 0.036). Notch1 expression was an independent prognostic factor in the multivariate analysis (p = 0.02). No other biomarker showed any prognostic impact in this highly selected SCLC cohort. DLL3 is highly expressed in the majority of advanced staged SCLC cases, as expected. In the same patient population, Notch1 expression might have a potential prognostic implication, by driving a non-neuroendocrine differentiation process. Given the small number of cases with Notch1 high expression, the results of this study needs to be confirmed on a larger cohort.

Topics: Aged; Antineoplastic Agents; Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Female; Gene Expression Regulation, Neoplastic; Humans; Intracellular Signaling Peptides and Proteins; Lung Neoplasms; Male; Membrane Proteins; Middle Aged; Platinum; Prognosis; Receptor, Notch1; Small Cell Lung Carcinoma; Survival Analysis; Transcription Factor HES-1; Treatment Outcome

Epidermal growth factor receptor (EGFR) pathway deregulation promotes the acquisition of stemlike properties in non-small-cell lung cancer. EGFR inhibition through NOTCH enriches lung cancer stem cells (CSCs). Src through Yes-associated protein 1 (YAP1) activates NOTCH. Signal transduction and activator of transcription 3 (STAT3) activation occurs upon EGFR blockade and regulates the generation of CSCs.. Using the Aldefluor assay kit, we investigated the enrichment of aldehyde dehydrogenase (ALDH)-positive cells in EGFR-mutation-positive cells treated with gefitinib, afatinib, and osimertinib. Western blot analysis was performed to evaluate changes in CSC marker expression upon EGFR blockade. We performed gene expression analysis in a cohort of EGFR-mutation-positive non-small-cell lung cancer patients. We evaluated the association of gene expression with treatment outcomes.. The cell subpopulation surviving EGFR inhibition had high ALDH activity and elevated CSC marker expression. Concurrent inhibition of EGFR, STAT3, and Src diminished the CSC subpopulation in an EGFR-mutation-positive cellular model. In a cohort of 64 EGFR-mutation-positive patients, 2 ALDH1 isoforms and the NOTCH target hairy and enhancer of split 1 (HES1), when highly expressed, were predictive of worse outcome to EGFR blockade. The gene expression of B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) that maintains the self-renewal of stem cells was also related to treatment outcome.. Single EGFR inhibitors increase the population of CSCs. Combinatory therapy targeting STAT3 and Src may be of potential benefit. ALDH1, HES1, and Bmi-1 are essential biomarkers in the initial assessment of EGFR-mutation-positive patients.

Topics: Aldehyde Dehydrogenase 1 Family; Antineoplastic Agents; Biomarkers, Tumor; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Drug Therapy, Combination; ErbB Receptors; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Mutation; Neoplastic Stem Cells; Polycomb Repressive Complex 1; Protein Kinase Inhibitors; src-Family Kinases; STAT3 Transcription Factor; Transcription Factor HES-1

Small-cell lung cancer (SCLC) is a highly malignant type of lung cancer with no effective second-line chemotherapy drugs. Arsenic trioxide (As

Topics: Adaptor Proteins, Signal Transducing; Angiogenesis Inhibitors; Animals; Arsenic Trioxide; Calcium-Binding Proteins; Cell Line, Tumor; Cell Proliferation; Collagen; Down-Regulation; Drug Combinations; Human Umbilical Vein Endothelial Cells; Humans; Intercellular Signaling Peptides and Proteins; Laminin; Lentivirus; Lung Neoplasms; Male; Mice, Nude; Proteoglycans; Receptors, Notch; Signal Transduction; Small Cell Lung Carcinoma; Transcription Factor HES-1; Up-Regulation; Xenograft Model Antitumor Assays

The alterations of sialylation on cell surface N-glycans due to overexpression of different sialyltransferases play a vital role in tumorigenesis and tumor progression. The β-galactoside α2-6-sialyltransferase 1 (ST6Gal-I) has been reported to be highly expressed in several cancers, including breast cancer, hepatocellular cancer and colon carcinoma. However, the roles and underlying mechanisms of ST6Gal-I in non-small cell lung cancer (NSCLC) still need to be elucidated. In this study, we determined that mRNA levels of ST3GAL1, ST6GALNAC3 and ST8SIA6 were remarkably reduced in lung cancer tissues and cells, whereas ST6GAL1 level significantly increased. The mRNA, protein and glycan levels of ST6Gal-I were higher in lung cancer tissues and cells. Moreover, down-regulation of ST6Gal-I decreased protein levels of Jagged1, DLL-1, Notch1, Hes1, Hey1, matrix-metalloproteinases (MMPs) and VEGF, and suppressed proliferation, migration and invasion capabilities of A549 and H1299 cells in vitro. In vivo, ST6Gal-I silencing suppressed tumorigenicity of NSCLC cells in athymic nude mice via the Notch1/Hes1/MMPs pathway. In addition, overexpression of Notch1 rescued the reduced growth and metastasis of A549 and H1299 cells resulted by ST6Gal-I silencing. Modification of α2,6-sialylation positively associates with lung cancer progression, thereby indicating that ST6Gal-I may mediate the invasiveness and tumorigenicity of NSCLC cells via the Notch1/Hes1/MMPs pathway both in vitro and in vivo. Thus, our results provide a novel therapeutic approach for blocking metastasis in lung cancer patients.

Topics: Adenocarcinoma; Adult; Aged; Aged, 80 and over; Animals; Antigens, CD; Apoptosis; Carcinoma, Non-Small-Cell Lung; Cell Movement; Cell Proliferation; Female; Humans; In Vitro Techniques; Lung Neoplasms; Male; Matrix Metalloproteinases; Mice; Mice, Nude; Middle Aged; N-Acetylneuraminic Acid; Neoplasm Invasiveness; Prognosis; Protein Processing, Post-Translational; Receptor, Notch1; Sialyltransferases; Transcription Factor HES-1; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Differentiation abnormalities are a hallmark of tuberous sclerosis complex (TSC) manifestations; however, the genesis of these abnormalities remains unclear. Here we report on mechanisms controlling the multi-lineage, early neuronal progenitor and neural stem-like cell characteristics of lymphangioleiomyomatosis (LAM) and angiomyolipoma cells. These mechanisms include the activation of a previously unreported Rheb-Notch-Rheb regulatory loop, in which the cyclic binding of Notch1 to the Notch-responsive elements (NREs) on the Rheb promoter is a key event. This binding induces the transactivation of Rheb. The identified NRE2 and NRE3 on the Rheb promoter are important to Notch-dependent promoter activity. Notch cooperates with Rheb to block cell differentiation via similar mechanisms in mouse models of TSC. Cell-specific loss of Tsc1 within nestin-expressing cells in adult mice leads to the formation of kidney cysts, renal intraepithelial neoplasia, and invasive papillary renal carcinoma.

Topics: Angiomyolipoma; Animals; Cell Differentiation; Female; Humans; Lung Neoplasms; Lymphangioleiomyomatosis; Male; Mice, SCID; Mice, Transgenic; Neural Crest; Promoter Regions, Genetic; Ras Homolog Enriched in Brain Protein; Receptor, Notch1; Transcription Factor HES-1; Tuberous Sclerosis; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins; Xenograft Model Antitumor Assays

Metastasis is the leading cause of death in lung cancer. Understanding the mechanisms underlying the process of metastasis is crucial for identifying novel anti-metastatic therapies. Studies indicate that the highly conserved developmental pathways, such as the Wnt and Notch signaling pathways, play important roles in the non-small cell lung cancer (NSCLC) tumorigenesis. However, the roles of both pathways in NSCLC metastasis are unclear. The present study aimed to investigate whether Wnt3a and Notch3, key components of the Wnt and Notch signaling pathways, respectively, regulate the metastatic abilities of NSCLC cells and whether there is some relationship during these regulatory events. Here, we observed that Wnt3a treatment upregulated, not only the protein expression of Notch3, but also the mRNA expression of Notch3 and its downstream genes, HES1 and HEYL. In addition, Wnt3a promoted cell invasion and anchorage-independent growth. Meanwhile, Wnt3a treatment caused epithelial‑mesenchymal transition (EMT)-like morphological changes and F-actin reorganization. The western blotting data showed that Wnt3a treatment decreased the expression of E-cadherin and increased the expression of N-cadherin and vimentin. Compared with Wnt3a treatment, Notch3 shRNA transfection had opposite effects. Furthermore, Notch3 shRNA weakened the effects of Wnt3a treatment on the in vitro cell invasion and EMT. Overall, these observations suggest that Wnt3a and Notch3 may promote the metastasis of NSCLC and Notch3 upregulation is required for the Wnt3a mediated increased metastatic abilities of NSCLC.

Topics: Actins; Basic Helix-Loop-Helix Transcription Factors; Cadherins; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Epithelial-Mesenchymal Transition; Homeodomain Proteins; Humans; Lung Neoplasms; Neoplasm Invasiveness; Neoplasm Metastasis; Receptor, Notch3; Receptors, Notch; Repressor Proteins; RNA Interference; RNA, Messenger; RNA, Small Interfering; Transcription Factor HES-1; Transcriptional Activation; Up-Regulation; Vimentin; Wnt Signaling Pathway; Wnt3A Protein

Hairy and enhancer of split 1 (Hes-1) protein is a downstream target of Notch signaling and is a basic helix-loop-helix transcriptional repressor. However, definitive evidence for a role in hepatocellular carcinoma (HCC) cells has not been reported. Here, Hes-1 was revealed to an important component of the Notch signaling cascade in HCC cell lines possessing different potential for lung metastasis.. RNAi mediated by plasmid constructs was used to analyze the role of Hes-1 in MHCC-97L HCC cells by assessing proliferation, apoptosis, cell migration and matrigel invasion following transfection. Hes-1 protein expression analysis in HCC tissue was also conducted by immunohistochemistry.. Our studies revealed that Hes-1 was decreased in HCC cell lines with higher lung metastasis potential at both the mRNA and protein levels. Down-regulation of the Hes-1 gene in MHCC-97L cells resulted in increased cell proliferation, reduced apoptosis and increased migration and invasion.. Hes-1 has potential prognostic value in post-surgical HCC patients and may be an independent prognostic indicator for overall survival and tumor recurrence. These findings have important implications for understanding the mechanisms by which Hes-1 participates in tumor proliferation and invasion.

Topics: Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Blotting, Western; Carcinoma, Hepatocellular; Cell Movement; Cell Proliferation; Down-Regulation; Female; Flow Cytometry; Follow-Up Studies; Homeodomain Proteins; Humans; Immunoenzyme Techniques; Liver Neoplasms; Lung Neoplasms; Lymphatic Metastasis; Male; Middle Aged; Neoplasm Invasiveness; Neoplasm Staging; Prognosis; Real-Time Polymerase Chain Reaction; Receptor, Notch1; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Small Interfering; Signal Transduction; Survival Rate; Transcription Factor HES-1; Tumor Cells, Cultured

Irradiation has been reported to increase radioresistance and epithelial-mesenchymal transition (EMT) in gastric cancer (GC) cells. The Notch pathway is critically implicated in cancer EMT and radioresistance. In the present study, we investigated the use of a Notch-1 inhibiting compound as a novel therapeutic candidate to regulate radiation-induced EMT in GC cells. According to previous screening, tangeretin, a polymethoxylated flavonoid from citrus fruits was selected as a Notch-1 inhibitor. Tangeretin enhanced the radiosensitivity of GC cells as demonstrated by MTT and colony formation assays. Tangeretin also attenuated radiation-induced EMT, invasion and migration in GC cells, accompanied by a decrease in Notch-1, Jagged1/2, Hey-1 and Hes-1 expressions. Tangeretin triggered the upregulation of miR-410, a tumor-suppressive microRNA. Furthermore, re-expression of miR-410 prevented radiation-induced EMT and cell invasion. An in vivo tumor xenograft model confirmed the antimetastasis effect of tangeretin as we observed in vitro. In nude mice, tumor size was considerably diminished by radiation plus tangeretin co-treatment. Tangeretin almost completely inhibited lung metastasis induced by irradiation. Tangeretin may be a novel antimetastatic agent for radiotherapy.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Calcium-Binding Proteins; Cell Cycle Proteins; Cell Line, Tumor; Epithelial-Mesenchymal Transition; Flavones; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Intercellular Signaling Peptides and Proteins; Jagged-1 Protein; Lung Neoplasms; Membrane Proteins; Mice; MicroRNAs; Radiation Tolerance; Receptor, Notch1; Serrate-Jagged Proteins; Stomach Neoplasms; Transcription Factor HES-1

Insulinoma-associated protein 1 (INSM1) is expressed exclusively in embryonic developing neuroendocrine (NE) tissues. INSM1 gene expression is specific for small-cell lung cancer (SCLC), along with achaete-scute homolog-like 1 (ASCL1) and several NE molecules, such as chromogranin A, synaptophysin, and neural cell adhesion molecule 1. However, the underlying biological role of INSM1 in lung cancer remains largely unknown. We first showed that surgically resected SCLC samples specifically expressed INSM1. Forced expression of the INSM1 gene in adenocarcinoma cell lines (H358 and H1975) induced the expression of ASCL1, brain-2 (BRN2), chromogranin A, synaptophysin, and neural cell adhesion molecule 1; in contrast, knockdown of the INSM1 gene by siRNA in SCLC (H69 and H889) decreased their expression. However, forced/knockdown expression of ASCL1 and BRN2 did not affect INSM1 expression. A chromatin immunoprecipitation study revealed that INSM1 bound to the promoter region of the ASCL1 gene. A xenotransplantation assay using tet-on INSM1 gene-transfected adenocarcinoma cell lines demonstrated that INSM1 induced NE differentiation and growth inhibition. Furthermore, we found that INSM1 was not expressed in non-small-cell lung cancer and some SCLC cell lines expressing Notch1-Hes1. By forced/knockdown expression of Notch1 or Hes1 genes, we revealed that Notch1-Hes1 signaling suppressed INSM1, as well as ASCL1 and BRN2. INSM1, expressed exclusively in SCLC, is a crucial regulator of NE differentiation in SCLCs, and is regulated by the Notch1-Hes1 signaling pathway.

Topics: Adenocarcinoma; Animals; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Gene Knockdown Techniques; Heterografts; Homeodomain Proteins; Humans; Lung Neoplasms; Mice, Inbred Strains; Neoplasm Proteins; Neoplasm Transplantation; Neuroendocrine Cells; POU Domain Factors; Receptor, Notch1; Repressor Proteins; Signal Transduction; Small Cell Lung Carcinoma; Transcription Factor HES-1

Rnd3/RhoE is a small Rho GTPase involved in the regulation of different cell behaviors. Dysregulation of Rnd3 has been linked to tumorigenesis and metastasis. Lung cancers are the leading cause of cancer-related death in the West and around the world. The expression of Rnd3 and its ectopic role in non-small cell lung cancer (NSCLC) remain to be explored. Here, we reported that Rnd3 was down-regulated in three NSCLC cell lines: H358, H520 and A549. The down-regulation of Rnd3 led to hyper-activation of Rho Kinase and Notch signaling. The reintroduction of Rnd3 or selective inhibition of Notch signaling, but not Rho Kinase signaling, blocked the proliferation of H358 and H520 cells. Mechanistically, Notch intracellular domain (NICD) protein abundance in H358 cells was regulated by Rnd3-mediated NICD proteasome degradation. Rnd3 regulated H358 and H520 cell proliferation through a Notch1/NICD/Hes1 signaling axis independent of Rho Kinase.

Topics: Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Down-Regulation; Gene Expression; Homeodomain Proteins; Humans; Lung Neoplasms; Receptors, Notch; rho GTP-Binding Proteins; rho-Associated Kinases; Signal Transduction; Transcription Factor HES-1

The cancer stem cell theory postulates that tumors contain a subset of cells with stem cell properties of self-renewal, differentiation, and tumor initiation. The purpose of this study is to determine the role of Notch activity in identifying lung cancer stem cells.. We investigated the role of Notch activity in lung adenocarcinoma using a Notch GFP reporter construct and a γ-secretase inhibitor (GSI), which inhibits Notch pathway activity.. Transduction of lung cancer cells with Notch GFP reporter construct identified a subset of cells with high Notch activity (GFP-bright). GFP-bright cells had the ability to form more tumor spheres in serum-free media and were able to generate both GFP-bright and GFP-dim (lower Notch activity) cell populations. GFP-bright cells were resistant to chemotherapy and were tumorigenic in serial xenotransplantation assays. Tumor xenografts of mice treated with GSI had decreased expression of downstream effectors of Notch pathway and failed to regenerate tumors upon reimplantation in NOD/SCID mice. Using multivariate analysis, we detected a statistically significant correlation between poor clinical outcome and Notch activity (reflected in increased Notch ligand expression or decreased expression of the negative modulators), in a group of 443 patients with lung adenocarcinoma. This correlation was further confirmed in an independent group of 89 patients with adenocarcinoma in which Hes-1 overexpression correlated with poor overall survival.. Notch activity can identify lung cancer stem cell-like population and its inhibition may be an appropriate target for treating lung adenocarcinoma.

Topics: Adenocarcinoma; Animals; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Cell Cycle; Cell Line, Tumor; Cyclic S-Oxides; Flow Cytometry; Gene Expression Regulation, Neoplastic; Green Fluorescent Proteins; Homeodomain Proteins; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Lung Neoplasms; Mice; Mice, Inbred NOD; Mice, Nude; Mice, SCID; Multivariate Analysis; Neoplastic Stem Cells; Protein Isoforms; Receptors, Notch; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Thiadiazoles; Transcription Factor HES-1; Xenograft Model Antitumor Assays

Delta-Like1 (DLL1) can combine with Notch receptor and activate the Notch signal pathway, then made a decision to cell differentiation and regulate the development of many tissues. It is proved that DLL1 was highly correlated with tumor'growth and differentiation, our previously study showed that DLL1 was associated with MDR in small cell lung cancer (SCLC). The aim of this study is to furtherly investigate the role of DLL1 gene in small cell lung multi-drug resistance.. Firstly, the analysis of qRT-PCR and Western blot were used to study differential expression of DLL1 from mRNA and protein levels in both the H69 and H69AR cell lines. Then, we developed a stably DDL1 overexpressing H69AR-eGFP-DLL1 subline, by transfection with DLL1-pIRES2-EGFP. Moreover, the sensitivities of cells to chemotherapy drugs such as ADM, DDP, VP-16 were detected by CCK8 assay. The change of cell cycle and apoptosis rate were detected by flow cytometry.. The expression of DLL1 was significantly decreased in H69AR cells than that in the H69 cells. The sensitivities of H69AR cells to chemotherapy drugs were increased when up-regulated the expression of DLL1, enforced DLL1 expression increased cell apoptosis and the cell cycle arrest in G0/G1 and S phase in H69AR cells, the expression of downstream genes HES1 and HEY1 were increased after transfected with DLL1-pIRES2-EGFP.. Our results suggest that overexpression of DLL1 in small cell lung cancer may increase the sensitivity of cells to chemotherapeutic agents. DLL1 influence drug resistance of small cell lung cancer through activating transcription of downstream genes HES1 and HEY1.. 背景与目的 DLL1（Delta-Like1）与Notch受体结合激活Notch信号通路，从而决定细胞的分化，并调控多种组织的生长发育。已有研究报道DLL1与肿瘤的生长、分化密切相关。前期基因芯片发现DLL1与小细胞肺癌的耐药性相关，本研究旨在进一步探讨DLL1在小细胞肺癌多药耐药中的作用。方法 首先通过QRT-PCR和Western blot从基因和蛋白水平检测化疗敏感细胞株H69及多药耐药细胞株H69AR中DLL1的差异表达；转染DLL1-pIRES2-EGFP表达质粒上调H69AR细胞中的DLL1的表达，构建稳定转染的过表达细胞株H69AR-eGFP-DLL1 ，通过CCK8检测细胞对各种化疗药物（ADM, DDP, VP-16）的敏感性变化，流式细胞仪检测细胞周期及凋亡的变化。结果 DLL1在化疗敏感细胞H69中的表达明显高于H69AR，过表达H69AR中DLL1的表达能够增加细胞对化疗药物的敏感性，促进细胞的凋亡，细胞周期发生G0/G1期及S期阻滞，上调DLL1增加其下游基因HES1、HEY1的表达。结论 在小细胞肺癌中上调DLL1的表达可能增加细胞对化疗药物的敏感性，DLL1通过肿瘤细胞间的相互作用激活HES1、HEY1等下游基因，影响小细胞肺癌的多药耐药。

Topics: Antineoplastic Agents; Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Blotting, Western; Calcium-Binding Proteins; Cell Cycle; Cell Cycle Proteins; Cell Line, Tumor; Cisplatin; Etoposide; Green Fluorescent Proteins; Homeodomain Proteins; Humans; Intercellular Signaling Peptides and Proteins; Lung Neoplasms; Membrane Proteins; Microscopy, Fluorescence; Reverse Transcriptase Polymerase Chain Reaction; Small Cell Lung Carcinoma; Transcription Factor HES-1; Up-Regulation

Tumor angiogenesis plays important roles in the pathogenesis and prognosis of lung cancer. Both vascular endothelial growth factor (VEGF) and Dll4/Notch pathways are critical for angiogenesis, whereas their relationship under hypoxia in lung cancer remains unknown. Thus, in the present study, we evaluated the expression of VEGF and Dll4/Notch signaling molecules, and assessed their association with the microvessel density (CD31) and hypoxia (HIF1a) in lung cancer and normal lung tissues using immunohistochemical and Real-time RT-PCR techniques. Then, we investigated the biological function of Dll4 by transfecting Dll4 into HUVECs. In lung cancer tissues, Notch pathway molecules (HES1) and VEGF pathway molecules (VEGFR1 and VEGFR2) were significantly up-regulated, while the ratio of VEGFR1/VEGFR2 was decreased. CD31 and HIF1a were also found to be elevated in lung cancer. VEGFR1 was negatively correlated with Notch1 while positively correlated with Dll4. CD31 was positively correlated with HIF1a but negatively correlated with VEGFR1. Moreover, HIF1a was nearly positively correlated with HES1 in lung cancer tissues. After transfection, Dll4, Notch1 and VEGFR1 were up-regulated while VEGF and VEGFR2 were down-regulated in Dll4-transfected HUVECs compared with controls. Also, our findings suggest that the expression of VEGF and VEGFR2 increased gradually with the disease progression of lung cancer. In summary, VEGF and Notch signaling pathway molecules were overexpressed in lung cancer, which positively correlates with hypoxia (HIF1a) and angiogenesis (CD31). There might be a negative feedback loop between VEGF and Dll4/Notch signaling pathway in lung tumor angiogenesis.

Topics: Adaptor Proteins, Signal Transducing; Adenocarcinoma; Adenocarcinoma of Lung; Adult; Aged; Aged, 80 and over; Basic Helix-Loop-Helix Transcription Factors; Calcium-Binding Proteins; Carcinoma, Squamous Cell; Cells, Cultured; Disease Progression; Female; Follow-Up Studies; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Intercellular Signaling Peptides and Proteins; Lung; Lung Neoplasms; Male; Middle Aged; Neovascularization, Pathologic; Platelet Endothelial Cell Adhesion Molecule-1; Receptors, Notch; Retrospective Studies; Signal Transduction; Transcription Factor HES-1; Umbilical Veins; Up-Regulation; Vascular Endothelial Growth Factor A

MicroRNAs (miRNAs) are small noncoding RNAs that play critical roles in regulating various cellular functions by transcriptional silencing. miRNAs can function as either oncogenes or tumor suppressors (oncomirs), depending on cancer types. In our study, using miRNA microarray, we observed that downregulation of the Notch-1 pathway, by delta-tocotrienol, correlated with upregulation of miR-34a, in nonsmall cell lung cancer cells (NSCLC). Moreover, re-expression of miR-34a by transfection in NSCLC cells resulted in inhibition of cell growth and invasiveness, induction of apoptosis and enhanced p53 activity. Furthermore, cellular mechanism studies revealed that induction of miR-34a decreased the expression of Notch-1 and its downstream targets including Hes-1, Cyclin D1, Survivin and Bcl-2. Our findings suggest that delta-tocotrienol is a nontoxic activator of mir-34a which can inhibit NSCLC cell proliferation, induce apoptosis and inhibit invasion, and thus offering a potential starting point for the design of novel anticancer agents.

Topics: Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Down-Regulation; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Inhibitor of Apoptosis Proteins; Lung Neoplasms; MicroRNAs; Neoplasm Invasiveness; Proto-Oncogene Proteins c-bcl-2; Receptor, Notch1; Signal Transduction; Survivin; Transcription Factor HES-1; Transfection; Tumor Suppressor Protein p53; Up-Regulation; Vitamin E

Here, we have investigated the role of the Notch pathway in the generation and maintenance of Kras(G12V)-driven non-small cell lung carcinomas (NSCLCs). We demonstrate by genetic means that γ-secretase and RBPJ are essential for the formation of NSCLCs. Of importance, pharmacologic treatment of mice carrying autochthonous NSCLCs with a γ-secretase inhibitor (GSI) blocks cancer growth. Treated carcinomas present reduced HES1 levels and reduced phosphorylated ERK without changes in phosphorylated MEK. Mechanistically, we show that HES1 directly binds to and represses the promoter of DUSP1, encoding a dual phosphatase that is active against phospho-ERK. Accordingly, GSI treatment upregulates DUSP1 and decreases phospho-ERK. These data provide proof of the in vivo therapeutic potential of GSIs in primary NSCLCs.

Topics: Amyloid Precursor Protein Secretases; Animals; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Dual Specificity Phosphatase 1; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Homeodomain Proteins; Humans; Lung Neoplasms; Mice; Mutant Proteins; Phosphorylation; Presenilin-1; Presenilin-2; Prognosis; Promoter Regions, Genetic; Protein Binding; ras Proteins; Receptors, Notch; Repressor Proteins; Signal Transduction; Transcription Factor HES-1; Treatment Outcome

The oncogenic potential of Notch activation is observed in many instances including lung tumorigenesis, but the associated molecular regulatory mechanism has not been thoroughly defined. It has been demonstrated that hypoxia can act as one of the major stimuli in the progression of many types of tumorigenesis. This study was designed to examine the activation of Notch-1 signaling by hypoxia and its contribution to survivin expression in human lung carcinomas. Western-blot and PCR analysis showed that Notch-1 signaling is activated by hypoxia in the human non-small cell lung cancer (NSCLC) cell line, A549, through the upregulation of Notch-1, along with its intracellular domain (N1ICD). The activity of Hes-1, a crucial target molecule of N1ICD, was also increased under hypoxia. Interestingly, blockade of the Notch-1 pathway by a γ-secretase inhibitor or small interfering RNA (siRNA) inhibited survivin expression. Conversely, activation of Notch-1 signaling by N1ICD or stimulation with the Jagged1 ligand enhanced survivin levels in A549 cells. Notably, HIF-1α cooperated with Notch-1 signaling to increase survivin expression through its direct association with N1ICD, consequently accelerating survivin transcription. Overall, our findings suggest that Notch-1 signaling is involved in the upregulation of survivin expression in lung cancer cells, which is synergized by HIF-1α.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Calcium-Binding Proteins; Carcinoma, Non-Small-Cell Lung; Cell Hypoxia; Cell Line, Tumor; Homeodomain Proteins; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Inhibitor of Apoptosis Proteins; Intercellular Signaling Peptides and Proteins; Jagged-1 Protein; Lung Neoplasms; Membrane Proteins; Promoter Regions, Genetic; Rats; Receptor, Notch1; RNA, Small Interfering; Serrate-Jagged Proteins; Signal Transduction; Survivin; Transcription Factor HES-1; Transfection; Up-Regulation

To clarify the biological differences between small cell lung carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC), we investigated the expression of two bHLH type transcription factors, human achaete-scute homolog 1 (hASH1) and hairy/enhancer of split 1 (HES1), which positively and negatively regulate the neuroendocrine differentiation of respiratory epithelial cells, respectively. Eighty-eight formalin-fixed and paraffin-embedded pulmonary carcinomas (32 SCLC, 32 LCNEC, 14 adenocarcinomas, and 10 squamous cell carcinomas) and 14 SCLC and 1 LCNEC derived cell lines were used. hASH1 and HES1 mRNA were detected using a highly sensitive in situ hybridization method with digoxigenin-labeled cRNA probes and biotinylated tyramide. The staining results were scored from 0 to 12 by multiplying the staining intensity by the percentage of positive tumor cells. The mean staining score of hASH1 mRNA was significantly higher in SCLC than in LCNEC (p<0.01); conversely, that of HES1 mRNA was lower in SCLC than in LCNEC (p<0.01). These findings reveal that SCLC more strongly expresses the neuroendocrine phenotype, while LCNEC shows characteristics more similar to the ciliated epithelium phenotype, suggesting that the biological characteristics of these two tumors are different.

Topics: Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Large Cell; Cell Line, Tumor; Cilia; Diagnosis, Differential; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; In Situ Hybridization; Lung Neoplasms; Neuroendocrine Cells; Proteomics; Respiratory Mucosa; RNA, Messenger; Small Cell Lung Carcinoma; Transcription Factor HES-1; Vascular Endothelial Growth Factor A

To investigate the status of Notch signaling pathway in small cell lung cancer (SCLC).. Expression plasmids of pEFBOS-NIC-MYC and pEFBOS-neo were transfected into NCI-H446 cells. Stably transfected cell lines were selected and their growth rates were examined by MTT method. Expression of downstream genes along the Notch signaling pathway were studied by RT-PCR. Protein expression of euroendocrine markers of CgA and NSE were detected by Western blot analysis and immunocytochemistry.. The expression of HES1 was increased in the pEFBOS-NIC-MYC group, but the expression of hASH in the pEFBOS-NIC-MYC group was decreased significantly. The transfected cells with pEFBOS-NIC-MYC plasmid showed a significantly slower growth rate compared with that of two control groups (P < 0.05, Student's t-test). Immunocytochemistry of NSE showed that PUs in the NIC transfected group, sham group and negative control group were 7.21 ± 0.59, 28.25 ± 1.46, 30.57 ± 1.31 respectively, the former one was smaller than the values of the latter two significantly (P < 0.01). Western blot analysis showed the grave scales of CgA in NIC transfected group and sham group to be 0.54 ± 0.03 and 0.99 ± 0.05 respectively (grave scales of the negative control was set as 1.00), the former one significantly smaller than that of the other two groups (P < 0.01). The grave scales of NSE in the NIC transfected group and sham group were 0.43 ± 0.02 and 1.07 ± 0.09 respectively (grave scales of the negative control was set as 1.00) and the former one was significantly smaller than the other two groups (P < 0.01).. Notch signaling pathway regulates SCLC cells through its inhibitory effect on hASH1 transcription via HES1 along with an expression inhibition of neuroendocrine markers in SCLC.

Topics: Basic Helix-Loop-Helix Transcription Factors; Cell Line, Tumor; Cell Proliferation; Chromogranin A; Homeodomain Proteins; Humans; Lung Neoplasms; Phosphopyruvate Hydratase; Plasmids; Receptor, Notch1; Recombinant Proteins; Signal Transduction; Small Cell Lung Carcinoma; Transcription Factor HES-1; Transfection

Epidermal growth factor receptor (EGFR) overexpression and activation are hallmarks of non-small cell lung carcinoma (NSCLC). Although EGFR-targeted therapies are used, the prognosis of NSCLC remains poor. ADAM17 induces activation of the EGFR through ligand cleavage. However, we show that inhibition or knockdown of ADAM17 markedly reduces tumorigenesis and survival to a large part independently from EGFR ligand shedding in NSCLC cells. These findings strongly indicate additional oncogenic mechanisms regulated by ADAM17. We identified Notch1 signaling as an ADAM17-controlled pathway and a critical regulator of anchorage-independent growth by using both Notch1 shRNA and ectopic expression of the active intracellular Notch1 fragment. Strikingly, Notch1 knockdown led to a strong reduction of EGFR expression in all analyzed cell lines. Proliferation, survival, and colony formation of Notch1-deficient cells were insensitive to EGF stimulation. Moreover, targeting Notch1 or ADAM17 resulted in substantial cell death, whereas EGFR inhibition predominantly induced cell cycle arrest. Immunohistochemical analysis of primary human tissue revealed a significant correlation between ADAM17, Notch1 signaling, and high EGFR expression levels. In conclusion, this article describes a novel molecular circuitry in NSCLC, incorporating ADAM17 as a regulator of EGFR expression through the activation of Notch1. Due to their central role in tumorigenesis and survival of NSCLC cells, both ADAM17 and Notch1 constitute promising targets for the treatment of NSCLC.

Topics: ADAM Proteins; ADAM17 Protein; Animals; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Non-Small-Cell Lung; Cell Growth Processes; Cell Line, Tumor; Cell Survival; Cell Transformation, Neoplastic; Epidermal Growth Factor; ErbB Receptors; Homeodomain Proteins; Humans; Lung Neoplasms; Mice; Receptor, Notch1; Signal Transduction; Transcription Factor HES-1; Transplantation, Heterologous

Notch signaling regulates cell specification and homeostasis of stem cell compartments, and it is counteracted by the cell fate determinant Numb. Both Numb and Notch have been implicated in human tumors. Here, we show that Notch signaling is altered in approximately one third of non-small-cell lung carcinomas (NSCLCs), which are the leading cause of cancer-related deaths: in approximately 30% of NSCLCs, loss of Numb expression leads to increased Notch activity, while in a smaller fraction of cases (around 10%), gain-of-function mutations of the NOTCH-1 gene are present. Activation of Notch correlates with poor clinical outcomes in NSCLC patients without TP53 mutations. Finally, primary epithelial cell cultures, derived from NSCLC harboring constitutive activation of the Notch pathway, are selectively killed by inhibitors of Notch (gamma-secretase inhibitors), showing that the proliferative advantage of these tumors is dependent upon Notch signaling. Our results show that the deregulation of the Notch pathway is a relatively frequent event in NSCLCs and suggest that it might represent a possible target for molecular therapies in these tumors.

Topics: Aged; Base Sequence; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Non-Small-Cell Lung; DNA Mutational Analysis; DNA, Neoplasm; Female; Gene Expression; Homeodomain Proteins; Humans; Lung Neoplasms; Male; Membrane Proteins; Middle Aged; Mutation; Nerve Tissue Proteins; Receptor, Notch1; Receptors, Notch; RNA, Messenger; RNA, Neoplasm; Signal Transduction; Transcription Factor HES-1; Tumor Cells, Cultured

The Notch1-signaling pathway has been shown to regulate the differentiation and growth of carcinoid tumor cells. However, the molecules that mediate Notch1 signaling, as well as their potential roles in regulating the growth of carcinoid tumors, have not been characterized. We and others have shown previously that the transcription factor Hairy Enhancer of Split-1 (HES-1) is upregulated in response to Notch1 signaling, demonstrating that it is a Notch1 effector. We hypothesized that HES-1 may be the essential downstream factor in Notch1-mediated growth regulation of carcinoid tumors.. H727 carcinoid tumor cells were transduced stably with a doxycycline-inducible HES-1 construct, creating H727-HES-1 cells. H727-TRE (vector-only control) and H727-HES-1 cells were then treated with varying concentrations of doxycycline to achieve increasing levels of HES-1 protein expression. Cell proliferation was determined with the use of a cell viability assay.. Treatment of H727-HES-1 cells with increasing dosages of doxycycline resulted in dose-dependent increases in HES-1 protein by Western blot analysis. Importantly, induction of HES-1 in carcinoid tumor cells led to suppression of tumor cellular proliferation. Moreover, the degree of carcinoid growth inhibition appeared to be proportional to the level of HES-1 induction.. HES-1 alone can regulate the growth of carcinoid tumor cells. Furthermore, these results suggest that HES-1 may be the critical downstream effector in the Notch1-signaling pathway.

Topics: Basic Helix-Loop-Helix Transcription Factors; Carcinoid Tumor; Cell Culture Techniques; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Doxycycline; Homeodomain Proteins; Humans; Lung Neoplasms; Receptor, Notch1; Transcription Factor HES-1

In neural development, Notch signaling plays a key role in restricting neuronal differentiation, promoting the maintenance of progenitor cells. Classically, Notch signaling causes transactivation of Hairy-enhancer of Split (HES) genes which leads to transcriptional repression of neural determination and differentiation genes. We now report that in addition to its known transcriptional mechanism, Notch signaling also leads to rapid degradation of the basic helix-loop-helix (bHLH) transcription factor human achaete-scute homolog 1 (hASH1). Using recombinant adenoviruses expressing active Notch1 in small-cell lung cancer cells, we showed that the initial appearance of Notch1 coincided with the loss of hASH1 protein, preceding the full decay of hASH1 mRNA. Overexpression of HES1 alone was capable of down-regulating hASH1 mRNA but could not replicate the acute reduction of hASH1 protein induced by Notch1. When adenoviral hASH1 was coinfected with Notch1, we still observed a dramatic and abrupt loss of the exogenous hASH1 protein, despite high levels of ongoing hASH1 RNA expression. Notch1 treatment decreased the apparent half-life of the adenoviral hASH1 protein and increased the fraction of hASH1 which was polyubiquitinylated. The proteasome inhibitor MG132 reversed the Notch1-induced degradation. The Notch RAM domain was dispensable but a lack of the OPA and PEST domains inactivated this Notch1 action. Overexpression of the hASH1-dimerizing partner E12 could protect hASH1 from degradation. This novel function of activated Notch to rapidly degrade a class II bHLH protein may prove to be important in many contexts in development and in cancer.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Small Cell; Cell Line; Cysteine Endopeptidases; Dimerization; DNA-Binding Proteins; Gene Expression Regulation, Neoplastic; Half-Life; Homeodomain Proteins; Humans; Lung Neoplasms; Membrane Proteins; Multienzyme Complexes; Muscle Proteins; Proteasome Endopeptidase Complex; Protein Processing, Post-Translational; Protein Structure, Tertiary; Receptor, Notch1; Receptors, Cell Surface; RNA, Messenger; Signal Transduction; TCF Transcription Factors; Transcription Factor 7-Like 1 Protein; Transcription Factor HES-1; Transcription Factors; Tumor Cells, Cultured; Ubiquitin

Among the various forms of human lung cancer, small cell lung cancer (SCLC) exhibits a characteristic neuroendocrine (NE) phenotype. Neural and NE differentiation in SCLC depend, in part, on the action of the basic-helix-loop-helix (bHLH) transcription factor human achaete-scute homologue-1 (hASH1). In nervous system development, the Notch signaling pathway is a critical negative regulator of bHLH factors, including hASH1, controlling cell fate commitment and differentiation. To characterize Notch pathway function in SCLC, we explored the consequences of constitutively active Notch signaling in cultured SCLC cells. Recombinant adenoviruses were used to overexpress active forms of Notch1, Notch2, or the Notch effector protein human hairy enhancer of split-1 (HES1) in DMS53 and NCI-H209 SCLC cells. Notch proteins, but not HES1 or control adenoviruses, caused a profound growth arrest, associated with a G1 cell cycle block. We found up-regulation of p21(waf1/cip1) and p27kip1 in concert with the cell cycle changes. Active Notch proteins also led to dramatic reduction in hASH1 expression, as well as marked activation of phosphorylated extracellular signal-regulated kinase (ERK)1 and ERK2, findings that have been shown to be associated with cell cycle arrest in SCLC cells. These data suggest that the previously described function of Notch proteins as proto-oncogenes is highly context-dependent. Notch activation, in the setting of a highly proliferative hASH1-dependent NE neoplasm, can be associated with growth arrest and apparent reduction in neoplastic potential.

Topics: Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Small Cell; Cell Cycle; Cell Cycle Proteins; Cell Division; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Cyclins; DNA-Binding Proteins; Enzyme Activation; G1 Phase; Helix-Loop-Helix Motifs; Homeodomain Proteins; Humans; Lung Neoplasms; MAP Kinase Signaling System; Membrane Proteins; Microtubule-Associated Proteins; Mitogen-Activated Protein Kinases; Muscle Proteins; Receptor, Notch1; Receptor, Notch2; Receptors, Cell Surface; Signal Transduction; Transcription Factor HES-1; Transcription Factors; Tumor Suppressor Proteins; Up-Regulation

The achaete-scute genes encode essential transcription factors in normal Drosophila and vertebrate nervous system development. Human achaete-scute homolog-1 (hASH1) is constitutively expressed in a human lung cancer with neuroendocrine (NE) features, small cell lung cancer (SCLC), and is essential for development of the normal pulmonary NE cells that most resemble this neoplasm. Mechanisms regulating achaete-scute homolog expression outside of Drosophila are presently unclear, either in the context of the developing nervous system or in normal or neoplastic cells with NE features. We now provide evidence that the protein hairy-enhancer-of-split-1 (HES-1) acts in a similar manner as its Drosophila homolog, hairy, to transcriptionally repress achaete-scute expression. HES-1 protein is detected at abundant levels in most non-NE human lung cancer cell lines which lack hASH1 but is virtually absent in hASH1-expressing lung cancer cells. Moreover, induction of HES-1 in a SCLC cell line down-regulates endogenous hASH1 gene expression. The repressive effect of HES-1 is directly mediated by binding of the protein to a class C site in the hASH1 promoter. Thus, a key part of the process that determines neural fate in Drosophila is conserved in human lung cancer cells. Furthermore, modulation of this pathway may underlie the constitutive hASH1 expression seen in NE tumors such as SCLC, the most virulent human lung cancer.

Topics: Animals; Base Sequence; Basic Helix-Loop-Helix Transcription Factors; beta-Galactosidase; Carcinoma, Small Cell; Cell Line; Conserved Sequence; DNA-Binding Proteins; Drosophila; Gene Expression Regulation, Neoplastic; Helix-Loop-Helix Motifs; Homeodomain Proteins; Humans; Lung Neoplasms; Oligodeoxyribonucleotides; Promoter Regions, Genetic; Recombinant Fusion Proteins; Transcription Factor HES-1; Transcription Factors; Transcription, Genetic; Transfection; Tumor Cells, Cultured; Vertebrates