hes1-protein--human and Neoplasm-Metastasis

Hes1 is one mammalian counterpart of the Hairy and Enhancer of split proteins that play a critical role in many physiological processes including cellular differentiation, cell cycle arrest, apoptosis and self-renewal ability. Recent studies have shown that Hes1 functions in the maintenance of cancer stem cells (CSCs), metastasis and antagonizing drug-induced apoptosis. Pathways that are involved in the up-regulation of Hes1 level canonically or non-canonically, such as the Hedgehog, Wnt and hypoxia pathways are frequently aberrant in cancer cells. Here, we summarize the recent data supporting the idea that Hes1 may have an important function in the maintenance of cancer stem cells self-renewal, cancer metastasis, and epithelial-mesenchymal transition (EMT) process induction, as well as chemotherapy resistance, and conclude with the possible mechanisms by which Hes1 functions have their effect, as well as their crosstalk with other carcinogenic signaling pathways.

Topics: Apoptosis; Basic Helix-Loop-Helix Transcription Factors; Carcinogenesis; Drug Resistance, Neoplasm; Epithelial-Mesenchymal Transition; Homeodomain Proteins; Humans; Neoplasm Metastasis; Neoplastic Stem Cells; Receptors, Notch; Signal Transduction; Transcription Factor HES-1

Numb, a stem cell fate determinant, acts as a tumor suppressor and is closely related to a wide variety of malignancies. Intrahepatic cholangiocarcinoma (iCCA) originates from hepatic progenitors (HPCs); however, the role of Numb in HPC malignant transformation and iCCA development is still unclear. A retrospective cohort study indicated that Numb was frequently decreased in tumor tissues and suggests poor prognosis in iCCA patients. Consistently, in a chemically induced iCCA mouse model, Numb was downregulated in tumor cells compared to normal cholangiocytes. In diet-induced chronic liver injury mouse models, Numb ablation significantly promoted histological impairment, HPC expansion, and tumorigenesis. Similarly, Numb silencing in cultured iCCA cells enhanced cell spheroid growth, invasion, metastasis, and the expression of stem cell markers. Mechanistically, Numb was found to bind to the Notch intracellular domain (NICD), and Numb ablation promoted Notch signaling; this effect was reversed when Notch signaling was blocked by γ-secretase inhibitor treatment. Our results suggested that loss of Numb plays an important role in promoting HPC expansion, HPC malignant transformation, and, ultimately, iCCA development in chronically injured livers. Therapies targeting suppressed Numb are promising for the treatment of iCCA.

Topics: Animals; Bile Duct Neoplasms; Body Weight; Carcinogenesis; Cell Proliferation; Cholangiocarcinoma; Down-Regulation; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Humans; Ki-67 Antigen; Liver; Liver Cirrhosis; Membrane Proteins; Mice, Inbred C57BL; Neoplasm Metastasis; Neoplastic Stem Cells; Nerve Tissue Proteins; Organ Size; Prognosis; Protein Domains; Receptors, Notch; Signal Transduction; Stem Cells; Transcription Factor HES-1

MicroRNAs (miRNAs) play a key role in the regulation of gene expression. In this study, we aimed to identify the clinical values of miR-1179 and to investigate the potential molecular mechanisms in breast cancer (BC).. RT-PCR was used to detect the expression levels of miR-1179 in both BC tissues and cell lines. We analyzed the association between the miR-1179 levels and clinicopathological factors and patient prognosis. The proliferation ability of miR-1179 on BC cells was assessed by MTT and colony formation assay. The role of miR-1179 in BC cells migration and invasion was measured by transwell assays. Western blot analysis was used to quantify the expression of the molecular biomarkers of the Notch signaling pathway.. Our results showed that miR-1179 expression was frequently downregulated in BC tissues and cell lines. Clinicopathologic analysis revealed that low miR-1179 expression is correlated with lymph node metastasis, advanced clinical stage and shorter overall survival. Multivariable Cox proportional hazards regression analysis suggested that increased miR-1179 expression was an independent prognostic factor of overall survival in BC patients. Gain-of-function assay indicated that the overexpression of miR-1179 significantly suppressed BC cells proliferation, migration and invasion. Mechanistically, miR-1179 up-regulation inhibited the expression of Notch 1, Notch 4 and Hes1, indicating that miR-1179 could suppress the activation of the Notch signaling pathway.. We showed that miR-1179 was a tumor suppressor that may serve as a novel potential prognostic biomarker or molecular therapeutic target for BC.

Topics: Breast Neoplasms; Cell Movement; Female; Gene Expression Regulation, Neoplastic; Humans; MCF-7 Cells; MicroRNAs; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Receptor, Notch1; Receptor, Notch4; Receptors, Notch; Signal Transduction; Transcription Factor HES-1; Up-Regulation

This study aimed to investigate the role of long non-coding RNA MEG3 (lncRNA MEG3) in osteosarcoma (OS) and further explore the underlying molecular mechanism.. The expression profiles of MEG3 in OS cell lines and normal osteoblast cell line were detected by qRT-PCR. MEG3 was over-expressed in OS cell line by using LV-MEG3. MTT and colony-formation assays were applied for cell proliferation analysis. Cell migration assay was applied to investigate the cell migration ability. In addition, the expression levels of cell growth and metastasis related factors (Notch1, Hes1, TGF-β, N-cadheren and E-cadheren) were determined to illustrate the mechanisms.. We found that compared with normal osteoblast hFOB1.19 cell line, MEG3 was significantly down-regulated in MG63 and U2OS cell lines, particularly in MG-63 cells. MEG3 was significantly up-regulated in MG63 cells by LV-MEG3. Cell proliferation and migration ability were obviously repressed by MEG3 over-expression. In addition, MEG3 over-expression markedly inhibited Notch1, Hes1,TGF-β and N-cadheren expression, and the expression level of E-cadheren was improved.. These results indicated that MEG3 could prevent cell growth and metastasis of OS by repressing Notch and TGF-β signaling pathway, thus providing a potential therapeutic target for OS treatment (Tab. 1, Fig. 4, Ref. 30).

Topics: Antigens, CD; Bone Neoplasms; Cadherins; Cell Line; Cell Line, Tumor; Cell Movement; Cell Proliferation; Down-Regulation; Gene Expression Regulation, Neoplastic; Humans; Neoplasm Metastasis; Osteoblasts; Osteosarcoma; Receptor, Notch1; RNA, Long Noncoding; Transcription Factor HES-1; Transforming Growth Factor beta; Tumor Stem Cell Assay; Up-Regulation

Little is known about the roles of Notch signaling in cholangiocarcinoma (CC). The expression of hairy and enhancer of split 1 (Hes-1) has not been investigated yet in resected specimens of CC. Notch signaling has been reported to be related to cancer stem cell (CSC) like properties in some malignancies. Our aim is to investigate the participation of Notch signaling in resected specimens of extrahepatic CC (EHCC) and to evaluate the efficacy of CC cells with CSC-like properties by Notch signaling blockade.. First, the expression of Notch1, 2, 3, 4 and Hes-1 was examined by immunohistochemistry in 132 resected EHCC specimens. The clinicopathological characteristics in the expression of Notch receptors and Hes-1 were investigated. Second, GSI IX, which is a γ-secretase-inhibitor, was used for Notch signaling blockade in the following experiment. Alterations of the subpopulation of CD24. Notch1, 2, 3, 4 and Hes-1 in the resected EHCC specimens were expressed in 50.0, 56.1, 42.4, 6.1, and 81.8 % of the total cohort, respectively. Notch1 and 3 expressions were associated with poorer histological differentiation (P = 0.008 and 0.053). The patients with the expression of at least any one of Notch1-3 receptors, who were in 80.3 % of the total, exhibited poorer survival (P = 0.050). Similarly, the expression of Hes-1 tended to show poor survival (P = 0.093). In all of the examined CC cell lines, GSI IX treatment significantly diminished the subpopulation of CD24. Aberrant Notch signaling is involved with EHCC. Inhibition of Notch signaling is a novel therapeutic strategy for targeting cells with CSC-like properties.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Bile Duct Neoplasms; Biomarkers; Cell Line, Tumor; Cell Proliferation; Cholangiocarcinoma; Disease Models, Animal; Female; Gene Expression; Heterografts; Humans; Immunohistochemistry; Immunophenotyping; Male; Middle Aged; Neoplasm Grading; Neoplasm Metastasis; Neoplasm Staging; Neoplastic Stem Cells; Receptors, Notch; Signal Transduction; Transcription Factor HES-1; Young Adult

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 enhancer of split-1 (HES1) is a transcriptional target of the Notch pathway, and a high level of HES1 is regarded as a marker of activated Notch. The aim of the study was to investigate the role of HES1 in colorectal cancer progression. We used tissue microarrays to analyze the expression and clinical significance of HES1 in 320 colorectal cancer samples. Stable overexpression and knockdown of HES1 were established in three colorectal cancer cell (CRC) lines (RKO, HCT8 and LOVO). We investigated the differentially expressed genes and enriched pathways in HES1 overexpressing CRC cells by gene expression profiling. Also, the role of HES1 in invasion and migration were examined in vitro and in vivo. We found that high expression of HES1 was significantly correlated with distal metastasis (P = 0.037) at diagnosis, and HES1 could serve as an unfavorable prognostic factor for colorectal cancer patients (P = 0.034). Gene expression profiling and pathway enrichment analysis revealed that HES1 was related to cellular adherens junction loss. In addition, we showed that HES1 overexpression lead to depressed E-cadherin, and elevated N-cadherin, vimentin and Twist-1 levels. Functionally, HES1 enhanced invasiveness and metastasis of CRC cells. HES1 promotes cancer metastasis via inducing epithelial mesenchymal transition and serves as a poor prognosis factor of colorectal cancer patients.

Topics: Adherens Junctions; Aged; Animals; Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Cell Line, Tumor; Colorectal Neoplasms; Female; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Homeodomain Proteins; Humans; Immunohistochemistry; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Neoplasm Metastasis; Prognosis; Receptors, Notch; Tissue Array Analysis; Transcription Factor HES-1; Treatment Outcome

Overexpression of the transcriptional factor Hes1 (hairy and enhancer of split-1) has been observed in numerous cancers, but the precise roles of Hes1 in epithelial-mesenchymal transition (EMT), cancer invasion and metastasis remain unknown. Our current study firstly revealed that Hes1 upregulation in a cohort of human nasopharyngeal carcinoma (NPC) biopsies is significantly associated with the EMT, invasive and metastatic phenotypes of cancer. In the present study, we found that Hes1 overexpression triggered EMT-like cellular marker alterations of NPC cells, whereas knockdown of Hes1 through shRNA reversed the EMT-like phenotypes, as strongly supported by Hes1-mediated EMT in NPC clinical specimens described above. Gain-of-function and loss-of-function experiments demonstrated that Hes1 promoted the migration and invasion of NPC cells in vitro. In addition, exogenous expression of Hes1 significantly enhanced the metastatic ability of NPC cells in vivo. Chromatin immunoprecipitation (ChIP) assays showed that Hes1 inhibited PTEN expression in NPC cells through binding to PTEN promoter region. Increased Hes1 expression and decreased PTEN expression were also observed in a cohort of NPC biopsies. Additional studies demonstrated that Hes1-induced EMT-like molecular changes and increased motility and invasion of NPC cells were mediated by PTEN. Taken together, our results suggest, for what we believe is the first time, that Hes1 plays an important role in the invasion and metastasis of NPC through inhibiting PTEN expression to trigger EMT-like phenotypes.

Topics: Animals; Carcinoma; Epithelial-Mesenchymal Transition; Female; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Nasopharyngeal Carcinoma; Nasopharyngeal Neoplasms; Neoplasm Invasiveness; Neoplasm Metastasis; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; Transcription Factor HES-1

Hes1 is a transcription factor that influences cell proliferation and differentiation. However, the effect of Hes1 on invasiveness and the underlying mechanism remain unknown. In the current study, we found that Hes1 suppressed cell apoptosis, promoted cell growth, induced EMT phenotype and cytoskeleton reconstruction, and enhanced the metastatic potential of colon cancer cells in vitro and in vivo. Furthermore, we indicated that Bmi-1 mediated Hes1-induced cell proliferation and migration, downregulated PTEN and activated the Akt/GSK3β pathway, consequently induced EMT and cytoskeleton reconstruction, ultimately leading to enhanced invasiveness of cancer cells. In addition, we also found that both Hes1 and Bmi-1 could directly regulate PTEN by associating at the PTEN locus, and played important roles in regulating PTEN/Akt/GSK3β pathway. Our results provide functional and mechanistic links between Hes1 and Bmi-1/PTEN/Akt/GSK3β signaling in the development and progression of colon cancer.

Topics: Basic Helix-Loop-Helix Transcription Factors; Cell Movement; Cell Proliferation; Colonic Neoplasms; Epithelial-Mesenchymal Transition; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Homeodomain Proteins; Humans; Neoplasm Invasiveness; Neoplasm Metastasis; Polycomb Repressive Complex 1; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Signal Transduction; Transcription Factor HES-1; Transfection

PTOV1 is an adaptor protein with functions in diverse processes, including gene transcription and protein translation, whose overexpression is associated with a higher proliferation index and tumor grade in prostate cancer (PC) and other neoplasms. Here we report its interaction with the Notch pathway and its involvement in PC progression.. Stable PTOV1 knockdown or overexpression were performed by lentiviral transduction. Protein interactions were analyzed by co-immunoprecipitation, pull-down and/or immunofluorescence. Endogenous gene expression was analyzed by real time RT-PCR and/or Western blotting. Exogenous promoter activities were studied by luciferase assays. Gene promoter interactions were analyzed by chromatin immunoprecipitation assays (ChIP). In vivo studies were performed in the Drosophila melanogaster wing, the SCID-Beige mouse model, and human prostate cancer tissues and metastasis. The Excel package was used for statistical analysis.. Knockdown of PTOV1 in prostate epithelial cells and HaCaT skin keratinocytes caused the upregulation, and overexpression of PTOV1 the downregulation, of the Notch target genes HEY1 and HES1, suggesting that PTOV1 counteracts Notch signaling. Under conditions of inactive Notch signaling, endogenous PTOV1 associated with the HEY1 and HES1 promoters, together with components of the Notch repressor complex. Conversely, expression of active Notch1 provoked the dismissal of PTOV1 from these promoters. The antagonist role of PTOV1 on Notch activity was corroborated in the Drosophila melanogaster wing, where human PTOV1 exacerbated Notch deletion mutant phenotypes and suppressed the effects of constitutively active Notch. PTOV1 was required for optimal in vitro invasiveness and anchorage-independent growth of PC-3 cells, activities counteracted by Notch, and for their efficient growth and metastatic spread in vivo. In prostate tumors, the overexpression of PTOV1 was associated with decreased expression of HEY1 and HES1, and this correlation was significant in metastatic lesions.. High levels of the adaptor protein PTOV1 counteract the transcriptional activity of Notch. Our evidences link the pro-oncogenic and pro-metastatic effects of PTOV1 in prostate cancer to its inhibitory activity on Notch signaling and are supportive of a tumor suppressor role of Notch in prostate cancer progression.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Biomarkers, Tumor; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Drosophila melanogaster; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Homeodomain Proteins; Humans; Male; Mice; Neoplasm Metastasis; Neoplasm Proteins; Prostatic Neoplasms; Receptors, Notch; Signal Transduction; Transcription Factor HES-1; Transcriptional Activation

Treating metastasis has been challenging due to tumors complexity and heterogeneity. This complexity is partly related to the crosstalk between tumor and its microenvironment. Endothelial cells -the building blocks of tumor vasculature- have been shown to have additional roles in cancer progression than angiogenesis and supplying oxygen and nutrients. Here, we show an alternative role for endothelial cells in supporting breast cancer growth and spreading independent of their vascular functions. Using endothelial cells and breast cancer cell lines MDA-MB231 and MCF-7, we developed co-culture systems to study the influence of tumor endothelium on breast tumor development by both in vitro and in vivo approaches. Our results demonstrated that endothelial cells conferred survival advantage to tumor cells under complete starvation and enriched the CD44HighCD24Low/- stem cell population in tumor cells. Moreover, endothelial cells enhanced the pro-metastatic potential of breast cancer cells. The in vitro and in vivo results concordantly confirmed a role for endothelial Jagged1 to promote breast tumor through notch activation. Here, we propose a role for endothelial cells in enhancing breast cancer progression, stemness, and pro-metastatic traits through a perfusion-independent manner. Our findings may be beneficial in developing novel therapeutic approaches.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Breast Neoplasms; Calcium-Binding Proteins; CD24 Antigen; Cell Line, Tumor; Cell Survival; Cells, Cultured; Cellular Microenvironment; Coculture Techniques; Endothelial Cells; Homeodomain Proteins; Humans; Hyaluronan Receptors; Intercellular Signaling Peptides and Proteins; Jagged-1 Protein; MCF-7 Cells; Membrane Proteins; Mice, Inbred NOD; Mice, Knockout; Mice, SCID; Microscopy, Confocal; Neoplasm Metastasis; Neoplastic Stem Cells; Receptors, Notch; Reverse Transcriptase Polymerase Chain Reaction; Serrate-Jagged Proteins; Transcription Factor HES-1; Transplantation, Heterologous

Controlling the spread of uveal melanoma is key to improving survival of patients with this common intraocular malignancy. The Notch ligand Jag2 has been shown to be upregulated in primary tumors that metastasize, and we therefore investigated its role in promoting invasion and clonogenic growth of uveal melanoma cells.. mRNA and protein expression of Notch pathway components were measured using qPCR and Western blot in uveal melanoma cell lines. Expression of Jag2 ligand was upregulated using Jag2-GFP-MSCV constructs or downregulated by sh-Jag2 in the uveal melanoma cell lines Mel285, Mel290, 92.1, and OMM1, and the effects on growth and invasion were assessed.. Jag2 was introduced into Mel285 and Mel290 cells, which have low baseline levels of both this ligand and Notch activity. Overall growth of the Jag2-expressing cultures increased somewhat, and a significant 3-fold increase in clonogenic growth in soft agar was also noted. Introduction of Jag2 increased motility in both wound-healing and transwell invasion assays. We also observed a significant increase in Jag2 and Hes1 mRNA in invasive OMM1 cells that had passed through a Matrigel-coated filter in the transwell assay when compared with noninvading cells. Loss-of-function studies performed in 92.1 and OMM1 lines using Jag2 shRNAs showed that downregulation of the ligand significantly suppressed cellular growth, invasion, and migration.. Our data suggest that Jag2 may play an important role in promoting Notch activity, growth, and metastasis in uveal melanoma.

Topics: Basic Helix-Loop-Helix Transcription Factors; Blotting, Western; Cell Line, Tumor; Cell Movement; Homeodomain Proteins; Humans; Intercellular Signaling Peptides and Proteins; Jagged-2 Protein; Ligands; MAP Kinase Signaling System; Melanoma; Membrane Proteins; Neoplasm Invasiveness; Neoplasm Metastasis; Phosphorylation; Real-Time Polymerase Chain Reaction; Receptors, Notch; RNA, Messenger; Signal Transduction; Transcription Factor HES-1; Up-Regulation; Uveal Neoplasms

Through negative regulation of gene expression, microRNAs (miRNAs) can function in cancers as oncosuppressors, and they can show altered expression in various tumor types. Here we have investigated medulloblastoma tumors (MBs), which arise from an early impairment of developmental processes in the cerebellum, where Notch signaling is involved in many cell-fate-determining stages. MBs occur bimodally, with the peak incidence seen between 3-4 years and 8-9 years of age, although it can also occur in adults. Notch regulates a subset of the MB cells that have stem-cell-like properties and can promote tumor growth. On the basis of this evidence, we hypothesized that miRNAs targeting the Notch pathway can regulated these phenomena, and can be used in anti-cancer therapies.. In a screening of MB cell lines, the miRNA miR-199b-5p was seen to be a regulator of the Notch pathway through its targeting of the transcription factor HES1. Down-regulation of HES1 expression by miR-199b-5p negatively regulates the proliferation rate and anchorage-independent growth of MB cells. MiR-199b-5p over-expression blocks expression of several cancer stem-cell genes, impairs the engrafting potential of MB cells in the cerebellum of athymic/nude mice, and of particular interest, decreases the MB stem-cell-like (CD133+) subpopulation of cells. In our analysis of 61 patients with MB, the expression of miR-199b-5p in the non-metastatic cases was significantly higher than in the metastatic cases (P = 0.001). Correlation with survival for these patients with high levels of miR-199b expression showed a positive trend to better overall survival than for the low-expressing patients. These data showing the down-regulation of miR-199b-5p in metastatic MBs suggest a potential silencing mechanism through epigenetic or genetic alterations. Upon induction of de-methylation using 5-aza-deoxycytidine, lower miR-199b-5p expression was seen in a panel of MB cell lines, supported an epigenetic mechanism of regulation. Furthermore, two cell lines (Med8a and UW228) showed significant up-regulation of miR-199b-5p upon treatment. Infection with MB cells in an induced xenograft model in the mouse cerebellum and the use of an adenovirus carrying miR-199b-5p indicate a clinical benefit through this negative influence of miR-199b-5p on tumor growth and on the subset of MB stem-cell-like cells, providing further proof of concept.. Despite advances in our understanding of the pathogenesis of MB, one-third of these patients remain incurable and current treatments can significantly damage long-term survivors. Here we show that miR-199b-5p expression correlates with metastasis spread, identifying a new molecular marker for a poor-risk class in patients with MB. We further show that in a xenograft model, MB tumor burden can be reduced, indicating the use of miR199b-5p as an adjuvant therapy after surgery, in combination with radiation and chemotherapy, for the improvement of anti-cancer MB therapies and patient quality of life. To date, this is the first report that expression of a miRNA can deplete the tumor stem cells, indicating an interesting therapeutic approach for the targeting of these cells in brain tumors.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Cell Proliferation; Down-Regulation; Homeodomain Proteins; Humans; Medulloblastoma; Mice; MicroRNAs; Neoplasm Metastasis; Neoplastic Stem Cells; Receptors, Notch; Transcription Factor HES-1; Xenograft Model Antitumor Assays

Prostate cancer bone metastases are characterized by their ability to induce osteoblastic lesions and local bone formation. It has been suggested that bone metastatic prostate cancer cells are osteomimetic and capable of expressing genes and proteins typically expressed by osteoblasts. The ability of preosteoblasts to differentiate and express osteoblastic genes depends on several pathways, including Notch and MAPK. Here we show that notch1 expression is increased 4-5 times in C4-2B and MDA PCa 2b cells (osteoblastic skeletal prostate metastatic cancer cell lines) when compared with nonskeletal metastatic cell lines (LNCaP and DU145). Notch1 ligand, dll1, is expressed only in C4-2B cells. Immunohistochemical studies demonstrate that Notch1 is present in both human clinical samples from prostate cancer bone metastases and the C4-2B cell line. To determine whether prostate cancer bone metastases respond to osteogenic induction similar to osteoblasts, C4-2B cells were cultured in osteogenic medium that promotes mineralization. C4-2B cells mineralize and express HES-1 (a downstream target of Notch), an effect that is completely inhibited by L-685,458, a Notch activity inhibitor. Furthermore, osteogenic induction increases ERK activation, runx2 expression, and nuclear localization, independent of Notch signaling. Finally, we show that Notch and ERK activation are essential for Runx2 DNA binding activity and osteocalcin gene expression in C4-2B cells in response to osteogenic induction. These studies demonstrate that prostate cancer bone metastatic cell lines acquire osteoblastic properties through independent activation of ERK and Notch signaling; presumably, both pathways are activated in the bone microenvironment.

Topics: Basic Helix-Loop-Helix Transcription Factors; Blotting, Western; Bone Neoplasms; Calcium; Carbamates; Cell Differentiation; Cell Line, Tumor; Cell Nucleus; Core Binding Factor Alpha 1 Subunit; Dipeptides; DNA; Enzyme Activation; Homeodomain Proteins; Humans; Immunohistochemistry; Intracellular Signaling Peptides and Proteins; Male; Membrane Proteins; Mitogen-Activated Protein Kinases; Models, Biological; Neoplasm Metastasis; Neoplasm Proteins; Osteoblasts; Prostatic Neoplasms; Protein Binding; Receptors, Notch; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA, Ribosomal, 18S; Signal Transduction; Time Factors; Transcription Factor HES-1; Transcription Factors

To evaluate the role of oncogenic RAS mutations in pancreatic tumorigenesis, we directed endogenous expression of KRAS(G12D) to progenitor cells of the mouse pancreas. We find that physiological levels of Kras(G12D) induce ductal lesions that recapitulate the full spectrum of human pancreatic intraepithelial neoplasias (PanINs), putative precursors to invasive pancreatic cancer. The PanINs are highly proliferative, show evidence of histological progression, and activate signaling pathways normally quiescent in ductal epithelium, suggesting potential therapeutic and chemopreventive targets for the cognate human condition. At low frequency, these lesions also progress spontaneously to invasive and metastatic adenocarcinomas, establishing PanINs as definitive precursors to the invasive disease. Finally, mice with PanINs have an identifiable serum proteomic signature, suggesting a means of detecting the preinvasive state in patients.

Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Carcinoma, Pancreatic Ductal; Cyclooxygenase 2; Genes, ras; Homeodomain Proteins; Humans; Immunohistochemistry; Isoenzymes; Matrix Metalloproteinase 7; Membrane Proteins; Mice; Mutation; Neoplasm Metastasis; Neoplasm Staging; Pancreas; Pancreatic Neoplasms; Prostaglandin-Endoperoxide Synthases; Transcription Factor HES-1