YKL-06-061 exerts antitumor effect through G1/S phase arrest by downregulating c-Myc and inhibition of metastasis via SIK1 upregulation in pancreatic cancer

Pancreatic cancer ranks fourth among cancer-related deaths with a low 5-year overall survival rate of less than 13%. At present, treatment of pancreatic cancer is still based on chemotherapy, but the efficacy is limited. Thus, a novel therapeutic agent for pancreatic cancer therapy is urgently needed. A library of compounds was screened, and YKL-06-061, a selective inhibitor of salt-inducible kinases (SIKs), was discovered for its ability of inhibiting the proliferation and metastasis of pancreatic cancer cells in vitro and reducing the growth of xenografts in nude mice in vivo . The results from transcriptome analysis showed that YKL-06-061 influenced the mRNA levels of many genes related to c-Myc and SIK1 signals. Based on this, it was found that YKL-06-061 induced cell cycle arrest at the G1 phase and decreased the levels of c-Myc, CDK4, and cyclin D1 protein. At the same time, YKL-06-061 inhibited invasion and metastasis of cancer cells, increased the levels of SIK1 and E-cadherin protein, and lowered vimentin and ZEB-1. Moreover, YKL-06-061 effectively enhanced the antiproliferation of gemcitabine or doxorubicin in pancreatic cancer cells in a synergistic manner. Collectively, these findings implicate YKL-06-061 as a promising therapeutic agent for patients with pancreatic cancer.