Chemokine 25–induced signaling suppresses colon cancer invasion and metastasis
Huanhuan Joyce Chen, … , Xiling Shen, Steven Lipkin
Huanhuan Joyce Chen, … , Xiling Shen, Steven Lipkin
Published August 6, 2012
Citation Information: J Clin Invest. 2012;122(9):3184-3196. https://doi.org/10.1172/JCI62110.
View: Text | PDF
Research Article Oncology

Chemokine 25–induced signaling suppresses colon cancer invasion and metastasis

Abstract

Chemotactic cytokines (chemokines) can help regulate tumor cell invasion and metastasis. Here, we show that chemokine 25 (CCL25) and its cognate receptor chemokine receptor 9 (CCR9) inhibit colorectal cancer (CRC) invasion and metastasis. We found that CCR9 protein expression levels were highest in colon adenomas and progressively decreased in invasive and metastatic CRCs. CCR9 was expressed in both primary tumor cell cultures and colon-cancer-initiating cell (CCIC) lines derived from early-stage CRCs but not from metastatic CRC. CCL25 stimulated cell proliferation by activating AKT signaling. In vivo, systemically injected CCR9+ early-stage CCICs led to the formation of orthotopic gastrointestinal xenograft tumors. Blocking CCR9 signaling inhibited CRC tumor formation in the native gastrointestinal CCL25+ microenvironment, while increasing extraintestinal tumor incidence. NOTCH signaling, which promotes CRC metastasis, increased extraintestinal tumor frequency by stimulating CCR9 proteasomal degradation. Overall, these data indicate that CCL25 and CCR9 regulate CRC progression and invasion and further demonstrate an appropriate in vivo experimental system to study CRC progression in the native colon microenvironment.

Authors

Huanhuan Joyce Chen, Robert Edwards, Serena Tucci, Pengcheng Bu, Jeff Milsom, Sang Lee, Winfried Edelmann, Zeynep H. Gümüs, Xiling Shen, Steven Lipkin

×

Figure 5

CCR9/CCL25 increases AKT signaling in early-stage CRC primary culture cells and CCICs.

Options: View larger image (or click on image) Download as PowerPoint
CCR9/CCL25 increases AKT signaling in early-stage CRC primary culture ce...
(A) IPA direct interaction network of differentially expressed genes between CCR9– and CCR9+ early-stage CCICs with signaling proteins known to be involved in the CCR9/CCL25 pathway (see SmartChip RT-PCR procedures and functional analysis). The solid lines correspond with all direct interactions in the IPA database. The dashed lines represent indirect interactions. Genes either with a log2 fold upregulation (red nodes) or downregulation (green nodes) are integrated in the signaling network. Blue lines correspond to direct interactions in NOTCH, AKT, and GSK-3β signaling pathways. (B) Levels of phosphorylated AKT (Ser473 and Thr308) and GSK-3β, which are increased by incubation with 0.5 or 1.0 μg/ml CCL25 for 30 minutes in early-stage CCICs, as shown by Western blot. β-Actin was used as loading control. (C) Levels of phospho-AKT (Ser473) in early-stage primary CRC-cultured cells and early-stage CCIC1 after 30 minutes of 0.5 μg/ml CCL25 treatment. The imaging analysis software Ariol SL-50 was used to evaluate immunofluorescence signals of cells (–) or CCL25 (+). *P < 0.001, compared with control by 1-way ANOVA. Error bars indicate SEM. (D) Phospho-AKT (Ser473) in early-stage primary CRC-cultured cells after treatment with 0.5 μg/ml CCL25 for 30 minutes as detected by immunofluorescence (green). Scale bar: 10 μm.