CRP2, a new invadopodia actin bundling factor critically promotes breast cancer cell invasion and metastasis

Abstract

A critical process underlying cancer metastasis is the acquisition by tumor cells of an invasive phenotype. At the subcellular level, invasion is facilitated by actin-rich protrusions termed invadopodia, which direct extracellular matrix (ECM) degradation. Here, we report the identification of a new cytoskeletal component of breast cancer cell invadopodia, namely cysteine-rich protein 2 (CRP2). We found that CRP2 was not or only weakly expressed in epithelial breast cancer cells whereas it was up-regulated in mesenchymal/invasive breast cancer cells. In addition, high expression of the CRP2 encoding gene CSRP2 was associated with significantly increased risk of metastasis in basal-like breast cancer patients. CRP2 knockdown significantly reduced the invasive potential of aggressive breast cancer cells, whereas it did not impair 2D cell migration. In keeping with this, CRP2-depleted breast cancer cells exhibited a reduced capacity to promote ECM degradation, and to secrete and express MMP-9, a matrix metalloproteinase repeatedly associated with cancer progression and metastasis. In turn, ectopic expression of CRP2 in weakly invasive cells was sufficient to stimulate cell invasion. Both GFP-fused and endogenous CRP2 localized to the extended actin core of invadopodia, a structure primarily made of actin bundles. Purified recombinant CRP2 autonomously crosslinked actin filaments into thick bundles, suggesting that CRP2 contributes to the formation/maintenance of the actin core. Finally, CRP2 depletion significantly reduced the incidence of lung metastatic lesions in two xenograft mouse models of breast cancer. Collectively, our data identify CRP2 as a new cytoskeletal component of invadopodia that critically promotes breast cancer cell invasion and metastasis.

Cysteine and glycine-rich protein 2 (CSRP2) transcript levels correlate with leukemia relapse and leukemia-free survival in adults with B-cell acute lymphoblastic leukemia and normal cytogenetics

“…Increased CSRP2 transcription also promotes migration of breast cancer cells via an actin bundling factor [18]. In our study CSRP2 was found predominantly in the nucleus.…”

H19 Noncoding RNA, an Independent Prognostic Factor, Regulates Essential Rb-E2F and CDK8-β-Catenin Signaling in Colorectal Cancer

“…Although H19 was reported to repress CDH1 expression via interaction with EZH2 (Luo et al, 2013), our findings of CDH1 regulation by H19 , and by both of H19 targets CDK8 and β-catenin, suggest a different mechanism on CDH1 regulation. CSRP2 is a rarely studied gene (Hoffmann et al, 2016), and in this study we identified its clear association with CRC survival. Interestingly, our unpublished data showed that E2F1 knockdown also dramatically reduces and increases CSRP2 and CDH1 mRNA expression, respectively.…”

Gemcitabine‐induced epithelial‐mesenchymal transition‐like changes sustain chemoresistance of pancreatic cancer cells of mesenchymal‐like phenotype

“…Wounds were done manually using the 9 6‐Well WoundMaker tool and filled with collagen. Invasion into the collagen matrix was followed using the IncuCyte device as previously described . Wound confluence was measured at each time point using the automated image acquisition and processing system IncuCyte.…”

“…Invasion into the collagen matrix was followed using the IncuCyte device as previously described. 20 Wound confluence was measured at each time point using the automated image acquisition and processing system IncuCyte. Relative wound density (RWD) was used to quantify wound closure.…”