The ability of LCRMP-1 to promote cancer invasion by enhancing filopodia formation is antagonized by CRMP-1
Szu-Hua Pan, … , Tse-Ming Hong, Pan-Chyr Yang
Szu-Hua Pan, … , Tse-Ming Hong, Pan-Chyr Yang
Published July 11, 2011
Citation Information: J Clin Invest. 2011;121(8):3189-3205. https://doi.org/10.1172/JCI42975.
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Research Article Oncology

The ability of LCRMP-1 to promote cancer invasion by enhancing filopodia formation is antagonized by CRMP-1

Abstract

Metastasis is a predominant cause of death in patients with cancer. It is a complex multistep process that needs to be better understood if we are to develop new approaches to managing tumor metastasis. Tumor cell invasion of the local stroma is suppressed by collapsin response mediator protein-1 (CRMP-1). Recently, we identified a long isoform of CRMP-1 (LCRMP-1), expression of which correlates with cancer cell invasiveness and poor clinical outcome in patients with non-small-cell lung cancer (NSCLC). Here, we report that LCRMP-1 overexpression in noninvasive human cell lines enhanced filopodia formation, cancer cell migration, and invasion via stabilization of actin. This effect required a highly conserved N-terminal region of LCRMP-1 as well as the WASP family verprolin-homologous protein-1/actin nucleation pathway (WAVE-1/actin nucleation pathway). Furthermore, LCRMP-1 appeared to act downstream of Cdc42, a Rho family protein known to be involved in actin rearrangement. In addition, LCRMP-1 associated with CRMP-1, which downregulated cancer cell metastasis by interrupting the association of LCRMP-1 and WAVE-1. Finally, we found that high-level expression of LCRMP-1 and low-level expression of CRMP-1 were associated with lymph node metastasis and poor survival in patients with NSCLC. In sum, we show that LCRMP-1 and CRMP-1 have opposing functions in regulating cancer cell invasion and metastasis and propose that this pathway may serve as a potential anticancer target.

Authors

Szu-Hua Pan, Yu-Chih Chao, Pei-Fang Hung, Hsuan-Yu Chen, Shuenn-Chen Yang, Yih-Leong Chang, Chen-Tu Wu, Cheng-Chi Chang, Wen-Lung Wang, Wing-Kai Chan, Yi-Ying Wu, Ting-Fang Che, Lu-Kai Wang, Chien-Yu Lin, Yung-Chie Lee, Min-Liang Kuo, Chau-Hwang Lee, Jeremy J.W. Chen, Tse-Ming Hong, Pan-Chyr Yang

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Figure 1

Function of LCRMP-1 in cancer invasion, migration, and metastasis.

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Function of LCRMP-1 in cancer invasion, migration, and metastasis. (A an...
(A and B) Protein levels of LCRMP-1 and CRMP-1 in CL1-0/LCRMP-1–overexpressing (4 stable clones, 1003, 1004, 1014, 1015; 2 controls, 2A2, 2A10) and CL1-5-F4/LCRMP-1–silenced (untreated [mock], oligofectamine [reagent only], LCRMP-1–targeting siRNA [LCRMP-1 silenced], or scrambled siRNA [nonsilenced]) cells were examined by immunoblotting. β-Actin was used as internal control. PT ratio, LCRMP-1 protein level normalized to that of mock. (A) Number of invading cells from LCRMP-1–expressing clones and (B) LCRMP-1–silenced cells quantified from modified Boyden chamber invasion assay (n = 3 experiments). (C) Effects of LCRMP-1 on cancer cell migration were examined by wound-healing assay in pools of stably transfected CL1-5/vector control, CL1-5/LCRMP-1, CL1-0/vector, CL1-0/LCRMP-1, CL1-5/nonsilenced, and CL1-5/LCRMP-1 silenced cells. Percentages of migrated cells were quantified from pictures taken at 0 and 12 hours after wounding (n = 6 experiments). (D–F) Effects of LCRMP-1 cancer metastasis in vivo examined by orthotopic implantation with stable (D) A549/LCRMP-1–overexpressing (left) or A549/LCRMP-1–silenced cells (right), and tail vein metastasis assays with (E) stable CL1-0/LCRMP-1–overexpressing (lines 1003 and 1015) or (F) CL1-5/LCRMP-1–silenced cells. Numbers of metastatic tumor nodules were calculated from 10 mice per group (n = 2 experiments). Histology was confirmed by H&E staining (original magnification, ×100). (D–F) Arrowheads indicate orthotopic or metastatic lung tumors. (E) The black arrowhead indicates where tumor cells invade blood vessels and form tumor thrombi. Error bars indicate mean ± SEM, and P values were calculated by 2-sided Student’s t test.