83394

PITPNM3

Chemokine (C-C motif) ligand 18 (CCL18), which is derived from tumour-associated macrophages (TAMs), plays a critical role in promoting breast cancer metastasis via its receptor, PYK2 N-terminal domain interacting receptor 1 (Nir1). However, the molecular mechanism by which Nir1 promotes breast cancer metastasis by binding to CCL18 remains elusive. In this study, Nir1 expression was associated with lymph node and distant metastasis in patients with invasive ductal carcinoma. For the first time, we report that Nir1 binding to CCL18 promotes the phosphorylation of Akt, LIN-11, Isl1 and MEC-3 protein domain kinase (LIMK), and cofilin, which is a critical step in cofilin recycling and actin polymerisation. Interestingly, Nir1 binding to CCL18 can enhance cell mesenchymal properties and induce epithelial-mesenchymal transition (EMT). Mechanistically, Nir1 binding to CCL18 stabilises Snail via the Akt/GSK3beta signalling pathway. In support of these observations, Nir1 binding to CCL18 promoted lung metastasis and LY294002 could inhibit it in vivo. In summary, our in vitro and in vivo results indicate that Nir1 binding to CCL18 plays an important role in breast cancer invasion/metastasis. This study identified both Nir1 and CCL18 as potential anti-invasion targets for therapeutic intervention in breast cancer.CI - Copyright (c) 2013 Elsevier Ltd. All rights reserved.

Chemokine ligand 18 (CCL18) has been associated with hepatocellular carcinoma (HCC) metastasis. Here, we demonstrated a novel mechanism through which CCL18 enhances cell migration, invasion, and epithelial-mesenchymal transition (EMT) in HCC. (1) Using immunohistochemistry, we analyzed the expression of PITPNM3, a molecule that correlated with CCL18 signaling, in 149 HCC tissue specimens. The results showed that PITPNM3 expression is highly associated with tumor metastasis and differentiation; (2) in vitro experiments showed that CCL18 enhances cell migration, invasion, and EMT in PITPNM3((+)) HCC cells but not in PITPNM3((-)) cells. Silencing of PITPNM3 by short interfering RNA (siRNA) inhibited the induction of cell migration, invasion, and EMT by CCL18; (3) Cell migration, invasion, and EMT induced by CCL18 accompanied with the phosphorylation of IKK and IKBalpha as well as p65 nuclear translocation in PITPNM3((+)) HCC cells, but not in the cells that PITPNM3 is silenced with siRNA, implying that the activation of NF-kappaB signaling is involved in the action of CCL18/PITPNM3. These results suggest that CCL18 enhances HCC cell migration, invasion, and EMT through the expression of PITPNM3 and the activation of the NF-kappaB signaling pathway.