Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.22 (cdc2)
 8,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CD133-positive cancer stem cells in colon cancer are resistant to conventional chemotherapy. The aim of the present study was to investigate the effect of celecoxib, a COX-2 inhibitor, on CD133 expression in HT29 and DLD1 cells. HT29 and DLD1 cells were treated with celecoxib using different concentrations and duration. CD133 expression was detected by flow cytometry, Western blotting, immunofluorescence, and quantitative real-time PCR. Wnt signaling pathway activity was measured by luciferase assay and gene expression changes were monitored using microarray analysis. HT29 cells showed significantly decreasing levels of CD133 expression with increasing concentrations of or duration of exposure to celecoxib. CD133 mRNA relative expression in HT29 and DLD1 cells also decreased with drug exposure. Furthermore, Wnt activation in HT29 and DLD1 cells decreased with celecoxib treatment. Gene expression microarray showed stemness genes, including Lgr5, Oct4, Prominin-1, Prominin-2, CXCR4, E2F8, CDK-2, were downregulated and differentiation genes, including CEACAM5, GDF, ADFP, ICAM1, were upregulated. Our results show that CD133 expression was downregulated by celecoxib through inhibition of the Wnt signaling pathway, which may be lead to cell differentiation.
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PMID:Celecoxib downregulates CD133 expression through inhibition of the Wnt signaling pathway in colon cancer cells. 2324 95

Neuroblastoma (NB) is a childhood tumor that arises from the sympathoadrenal lineage. MYCN amplification is the most reliable marker for poor prognosis and MYCN overexpression in embryonic mouse sympathetic ganglia results in NB-like tumors. MYCN cooperates with mutational activation of anaplastic lymphoma kinase (ALK), which promotes progression to NB, but the role of MYCN and ALK in tumorigenesis is still poorly understood. Here, we use chick sympathetic neuroblasts to examine the normal function of MYCN and MYC in the control of neuroblast proliferation, as well as effects of overexpression of MYCN, MYC, and activated ALK, alone and in combination. We demonstrate that MYC is more strongly expressed than MYCN during neurogenesis and is important for in vitro neuroblast proliferation. MYC and MYCN overexpression elicits increased proliferation but does not sustain neuroblast survival. Unexpectedly, long-term expression of activated ALKF1174L leads to cell-cycle arrest and promotes differentiation and survival of postmitotic neurons. ALKF1174L induces NEFM, RET, and VACHT and results in decreased expression of proapototic (BMF, BIM), adrenergic (TH), and cell-cycle genes (e.g., CDC25A, CDK1). In contrast, neuroblast proliferation is maintained when MYCN and ALKF1174L are coexpressed. Proliferating MYCN/ALKF1174L neuroblasts display a differentiated phenotype but differ from ALK-expressing neurons by the upregulation of SKP2, CCNA2, E2F8, and DKC1 Inhibition of the ubiquitin ligase SKP2 (S-phase kinase-associated protein 2), which targets the CDK inhibitor p27 for degradation, reduces neuroblast proliferation, implicating SKP2 in the maintained proliferation of MYCN/ALKF1174L neuroblasts. Together, our results characterize MYCN/ALK cooperation leading to neuroblast proliferation and survival that may represent initial steps toward NB development.
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PMID:Proliferation and Survival of Embryonic Sympathetic Neuroblasts by MYCN and Activated ALK Signaling. 2770 76