4-(5-benzo(1-3)dioxol-5-yl-4-pyridin-2-yl-1h-imidazol-2-yl)benzamide and Carcinoma--Renal-Cell

Clear cell renal cell carcinoma (ccRCC) is by far the most common type of kidney cancer and is characterized by loss of the tumor suppressor gene von Hippel-Lindau (VHL). ccRCC patients with metastatic disease has poor prognosis and today's therapy is insufficient. The cytokine Transforming Growth Factor-β (TGF-β) has been extensively studied in tumor biology and is believed to serve a variety of functions in tumor progression. We have previously shown that inhibition of NOTCH signaling causes a reduced migratory and invasive capacity of ccRCC cells, at least partly by a cross-talk with the TGF-β pathway. In the present study we aimed to further clarify the role of TGF-β signaling in ccRCC. We investigated the effects of TGF-β pathway modulation and showed that TGF-β inhibition attenuates the invasive capacity of ccRCC cells. By performing expression profiling we obtained a gene signature of the TGF-β induced response in ccRCC cells. The expression analyses revealed an extensive overlap between the TGF-β response and genes regulated by the hypoxia inducible factor (HIF). The link between the hypoxic and the TGF-β pathways was further corroborated by functional experiments, which demonstrated that TGF-β pathway activity was attenuated upon reintroduction of functional VHL in ccRCC.

Topics: Benzamides; Blotting, Western; Carcinoma, Renal Cell; Cell Line, Tumor; Cell Proliferation; Dioxoles; Enzyme-Linked Immunosorbent Assay; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Humans; Kidney Neoplasms; Oligonucleotide Array Sequence Analysis; Phosphorylation; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type I; Receptors, Transforming Growth Factor beta; Signal Transduction; Smad2 Protein; Transforming Growth Factor beta; Von Hippel-Lindau Tumor Suppressor Protein

Despite recent progress, therapy for metastatic clear cell renal cell carcinoma (CCRCC) is still inadequate. Dysregulated Notch signaling in CCRCC contributes to tumor growth, but the full spectrum of downstream processes regulated by Notch in this tumor form is unknown.. We show that inhibition of endogenous Notch signaling modulates TGF-β dependent gene regulation in CCRCC cells. Analysis of gene expression data representing 176 CCRCCs showed that elevated TGF-β pathway activity correlated significantly with shortened disease specific survival (log-rank test, p = 0.006) and patients with metastatic disease showed a significantly elevated TGF-β signaling activity (two-sided Student's t-test, p = 0.044). Inhibition of Notch signaling led to attenuation of both basal and TGF-β1 induced TGF-β signaling in CCRCC cells, including an extensive set of genes known to be involved in migration and invasion. Functional analyses revealed that Notch inhibition decreased the migratory and invasive capacity of CCRCC cells.. An extensive cross-talk between the Notch and TGF-β signaling cascades is present in CCRCC and the functional properties of these two pathways are associated with the aggressiveness of this disease.

Topics: Benzamides; Blotting, Western; Carcinoma, Renal Cell; Cell Line, Tumor; Cell Movement; Cell Proliferation; Dioxoles; Dipeptides; Humans; Receptor, Notch1; Receptors, Notch; Signal Transduction; Transforming Growth Factor beta; Transforming Growth Factor beta1