Effect of Dickkopf-1 (Dkk-1) and SP600125, a JNK Inhibitor, on Wnt Signaling in Canine Prostate Cancer Growth and Bone Metastases Wachiraphan Supsavhad 1 2, Bardes B Hassan 1 3,

Human Dickkopf-1 (Dkk-1) upregulates a noncanonical Wnt/JNK pathway, resulting in osteoclast stimulation, cell proliferation, and epithelial-to-mesenchymal transition (EMT) of cancer cells. Ace-1-Dkk-1, a canine prostate cancer (PCa) cell line overexpressing Dkk-1, was used to investigate Wnt signaling pathways in PCa tumor growth. SP600125, a JNK inhibitor, was used to examine whether it would decrease tumor growth and bone tumor phenotype in canine PCa cells in vitro and in vivo. Ace-1-VectorYFP-Luc and Ace-1-Dkk-1YFP-Luc cells were transplanted subcutaneously, while Ace-1-Dkk-1YFP-Luc was transplanted intratibially into nude mice. The effects of Dkk-1 and SP600125 on cell proliferation, in vivo tumor growth, and bone tumor phenotype were investigated. The mRNA expression levels of Wnt/JNK-related genes were measured using RT-qPCR. Dkk-1 significantly increased the mRNA expression of Wnt/JNK-signaling-related genes. SP600125 significantly upregulated the mRNA expression of osteoblast differentiation genes and downregulated osteoclastic-bone-lysis-related genes in vitro. SP600125 significantly decreased tumor volume and induced spindle-shaped tumor cells in vivo. Mice bearing intratibial tumors had increased radiographic density of the intramedullary new bone, large foci of osteolysis, and increased cortical lysis with abundant periosteal new bone formation. Finally, SP600125 has the potential to serve as an alternative adjuvant therapy in some early-stage PCa patients, especially those with high Dkk-1 expression.

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Cat.No. Product Name Information
S1460 SP600125 SP600125 (Nsc75890) is a broad-spectrum JNK inhibitor for JNK1, JNK2 and JNK3 with IC50 of 40 nM, 40 nM and 90 nM in cell-free assays, respectively; 10-fold greater selectivity against MKK4, 25-fold greater selectivity against MKK3, MKK6, PKB, and PKCα, and 100-fold selectivity against ERK2, p38, Chk1, EGFR etc. SP600125 is also a broad‐spectrum inhibitor of serine/threonine kinases including Aurora kinase AFLT3 and TRKA with of IC50 of 60 nM, 90 nM and 70 nM. SP600125 inhibits autophagy and activates apoptosis.

Related Targets

Aurora Kinase JNK Autophagy FLT3 Apoptosis related Trk receptor Serine/threonin kinase