The anthelmintic drug niclosamide induces GSK-ß-mediated ß-catenin degradation to potentiate gemcitabine activity, reduce immune evasion ability and suppress pancreatic cancer progression.

Niclosamide, a cell-permeable salicylanilide, was approved by the Food and Drug Administration for its anthelmintic efficiency. A growing body of evidence in recent years suggests that niclosamide exhibits potential tumor-suppressive activity. However, the role and molecular mechanism of niclosamide in pancreatic cancer remain unclear. In this study, niclosamide inhibited proliferation of pancreatic cancer cells (PCCs), induced apoptosis via the mitochondrial-mediated pathway, and suppressed cell migration and invasion by antagonizing epithelial-to-mesenchymal transition. Also, niclosamide inhibited tumor growth and metastasis in pancreatic cancer xenograft mouse models. Mechanistically, niclosamide exerted these therapeutic effects via targeting ß-catenin. Niclosamide did not reduce ß-catenin mRNA expression in PCCs, but significantly downregulated its protein level. Moreover, niclosamide induced ß-catenin phosphorylation and protein degradation. Interestingly, niclosamide also induced GSK-3ß phosphorylation, which is involved in the ubiquitination degradation of ß-catenin. Pharmacological activation of ß-catenin by methyl vanillate and ß-catenin overexpression abolished the inhibitory effects of niclosamide. Furthermore, niclosamide potentiated the antitumor effect of the chemotherapy drug gemcitabine and reduced the ability of cancer immune evasion by downregulating the expression levels of PD-L1, which is involved in T cell immunity. Thus, our study indicated that niclosamide induces GSK-ß-mediated ß-catenin degradation to potentiate gemcitabine activity, reduce immune evasion ability, and suppress pancreatic cancer progression. Niclosamide may be a potential therapeutic candidate for pancreatic cancer.

The isoflavone puerarin exerts anti-tumor activity in pancreatic ductal adenocarcinoma by suppressing mTOR-mediated glucose metabolism.

Puerarin (8-(ß-D-glucopyranosyl)-4', 7-dihydroxyisoflavone), a natural flavonoid compound isolated from the traditional Chinese herb Radix puerariae, have been demonstrated has potential anti-tumor effects via induction of apoptosis and inhibition of proliferation. However, the effect and molecular mechanism of puerarin in pancreatic ductal adenocarcinoma (PDAC) remains unknown. In this study, the tumor-suppressive effects of puerarin were determined by both in-vitro and in-vivo assays. The effects of puerarin on the proliferation, apoptosis, migration and invasion of pancreatic cancer cells (PCCs), and tumor growth and metastasis in PDAC xenograft mouse model were performed. Puerarin treatment significantly repressed PCC proliferation. Puerarin induced the mitochondrial-dependent apoptosis of PCCs by causing a Bcl-2/Bax imbalance. Moreover, puerarin inhibited PCC migration and invasion by antagonizing epithelial-mesenchymal transition (EMT). In nude mouse model, PDAC growth and metastasis were reduced by puerarin administration. Mechanistically, puerarin exerted its therapeutic effects on PDAC by suppressing Akt/mTOR signaling. Importantly, puerarin bound to the kinase domain of mTOR protein, affecting the activity of the surrounding amino acid residues associated with the binding of the ATP-Mg2+ complex. Further studies showed that the inhibitory effects of puerarin on PCCs were abolished by a mTOR activator, indicating a crucial role of mTOR in anti-tumor effects of puerarin in PDAC. As a result, puerarin hindered glucose uptake and metabolism by downregulating the oxygen consumption rate (OCR) and the extracellular acidification rate (ECAR) dependent upon HIF-1α and glucose transporter GLUT1. Therefore, these findings indicated that puerarin has therapeutic potential for the treatment of PDAC by suppressing glucose uptake and metabolism via Akt/mTOR activity.