constitutive and treatment-induced cxcl8-signalling selectively modulates the efficacy of anti-metabolite therapeutics in metastatic prostate cancer本构和treatment-induced cxcl8-signalling选择性地调节anti-metabolite治疗在转移性前列腺癌的功效.pdfVIP

Constitutive and Treatment-Induced CXCL8-Signalling Selectively Modulates the Efficacy of Anti-Metabolite Therapeutics in Metastatic Prostate Cancer Catherine Wilson., Pamela J. Maxwell., Daniel B. Longley, Richard H. Wilson, Patrick G. Johnston, David J. J. Waugh* Centre for Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, Northern Ireland Abstract Background: The current study was undertaken to characterize the effect of anti-metabolites on inducing CXCL8 signaling and determining whether the constitutive and/or drug-induced CXCL8 signaling in metastatic prostate cancer (CaP) cells modulates their sensitivity to this class of agent. Methods: The response of metastatic CaP cells to 5-Fluorouracil (5-FU), Pemetrexed or Tomudex was determined using cell count assays, flow cytometry and PARP cleavage analysis. Quantitative-PCR, ELISA and immunoblots were employed to determine effects of drugs or CXCL8 administration on target gene/protein expression. Results: Administration of 5-FU but not pemetrexed potentiated CXCL8 secretion and increased CXCR1 and CXCR2 gene expression in metastatic PC3 cells. Consistent with this, the inhibition of CXCL8 signaling using a CXCR2 antagonist, A increased the cytotoxicity of 5-FU by 4-fold (P,0.001), and increased 5-FU-induced apoptosis in PC3 cells (P,0.01). In contrast, while administration of A had no effect on the sensitivity of pemetrexed, the CXCR2 antagonist exerted the greatest effect in increasing the sensitivity of PC3 cells to Tomudex, a directed thymidylate synthase (TS) inhibitor. Subsequent experiments confirmed that administration of recombinant human CXCL8 increased TS expression, a response mediated in part by the CXCR2 receptor. Moreover, siRNA-mediated knockdown of the CXCL8-target