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IGFBP-rP1 suppresses epithelial-mesenchymal transition and metastasis in colorectal cancer.

Zhu S, Zhang J, Xu F, Xu E, Ruan W, Ma Y, Huang Q, Lai M - Cell Death Dis (2015)

Bottom Line: Cooperation of transforming growth factor-β (TGF-β) and other signaling pathways, such as Ras and Wnt, is essential to inducing EMT, but the molecular mechanisms remain to be fully determined.Here, we reported that insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1), a potential tumor suppressor, controls EMT in colorectal cancer progression.Moreover, we demonstrated that IGFBP-rP1 suppresses EMT and tumor metastasis by repressing TGF-β-mediated EMT through the Smad signaling cascade.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Pathology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China [2] Key Laboratory of Disease Proteomics of Zhejiang Province, Hangzhou, Zhejiang, China.

ABSTRACT
Epithelial-mesenchymal transition (EMT) was initially recognized during organogenesis and has recently been reported to be involved in promoting cancer invasion and metastasis. Cooperation of transforming growth factor-β (TGF-β) and other signaling pathways, such as Ras and Wnt, is essential to inducing EMT, but the molecular mechanisms remain to be fully determined. Here, we reported that insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1), a potential tumor suppressor, controls EMT in colorectal cancer progression. We revealed the inhibitory role of IGFBP-rP1 through analyses of clinical colorectal cancer samples and various EMT and metastasis models in vitro and in vivo. Moreover, we demonstrated that IGFBP-rP1 suppresses EMT and tumor metastasis by repressing TGF-β-mediated EMT through the Smad signaling cascade. These data establish that IGFBP-rP1 functions as a suppressor of EMT and metastasis in colorectal cancer.

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Related in: MedlinePlus

IGFBP-rP1 blocks TGF-β1-induced EMT in HT29 cells. (a) HT29 cells were incubated with TGF-β1 (10 ng/ml) for the indicated times. The levels of P-smad2/3 were assessed by western blot. (b) Expression of EMT markers assessed by western blot. (c) TGF-β1 promoted cell migration determined by transwell migration assay. The results were shown as mean+S.D. from triplicate experiments. (d, e) Western blot of the indicated antibodies and transwell migration assay in HT29 cells and controls untreated or treated with 1 μg/ml rhIGFBP-rP1 and/or 10 ng/ml TGF-β1. The results were shown as mean+S.D. from triplicate experiments
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fig6: IGFBP-rP1 blocks TGF-β1-induced EMT in HT29 cells. (a) HT29 cells were incubated with TGF-β1 (10 ng/ml) for the indicated times. The levels of P-smad2/3 were assessed by western blot. (b) Expression of EMT markers assessed by western blot. (c) TGF-β1 promoted cell migration determined by transwell migration assay. The results were shown as mean+S.D. from triplicate experiments. (d, e) Western blot of the indicated antibodies and transwell migration assay in HT29 cells and controls untreated or treated with 1 μg/ml rhIGFBP-rP1 and/or 10 ng/ml TGF-β1. The results were shown as mean+S.D. from triplicate experiments

Mentions: The relevance of the pathway was next examined in HT29 colorectal cancer cells. Here, addition of TGF-β1 induced a time-dependent increase of phosphorylated Smad2/3 protein levels, with 24 h TGF-β having the maximal activation effect in HT29 cells (Figure 6a). In response to TGF-β1 stimulation for 24 h, although the level of E-cadherin showed no apparent change, HT29 cells underwent EMT as determined by downregulation of the epithelial marker ZO-1 with concomitant upregulation of MMP9 and Snail (Figure 6b) as well as increased cell migration (Figure 6c). These data suggested that we had not only established the classical model of TGF-β1-induced EMT, but that it also activated the TGF-β/Smad cascade in HT29 cells. To further evaluate whether IGFBP-rP1 reversed TGF-β1-induced EMT-related changes, we performed a rescue experiment by adding exogenous rhIGFBP-rP1 protein. Consistent with our findings in the other cell lines, treatment with rhIGFBP-rP1 alone decreased TGF-β receptor and phospho-Smad2/3 expression levels as well as inhibited EMT program (Figure 6d, lane 2). This was accompanied by an obvious decrease of HT29 cells invasive ability (Figure 6e, lane 2). Treatment with TGF-β alone activated EMT program, TGF-β receptors, and its downstream molecules (Figure 6d, lane 3). Of note, exogenous rhIGFBP-rP1 protein decreased the activation of TGF-β signaling and restored the upregulation of TGF-β1-induced EMT-related markers (Figure 6d, lane 4 compare with lane 3). Accordingly, rhIGFBP-rP1 decreased the promotion of migration triggered by TGF-β1 (Figure 6e). These data collectively provide evidence that IGFBP-rP1 suppresses EMT by attenuation of TGF-β/Smad signaling in colorectal cancer.


IGFBP-rP1 suppresses epithelial-mesenchymal transition and metastasis in colorectal cancer.

Zhu S, Zhang J, Xu F, Xu E, Ruan W, Ma Y, Huang Q, Lai M - Cell Death Dis (2015)

IGFBP-rP1 blocks TGF-β1-induced EMT in HT29 cells. (a) HT29 cells were incubated with TGF-β1 (10 ng/ml) for the indicated times. The levels of P-smad2/3 were assessed by western blot. (b) Expression of EMT markers assessed by western blot. (c) TGF-β1 promoted cell migration determined by transwell migration assay. The results were shown as mean+S.D. from triplicate experiments. (d, e) Western blot of the indicated antibodies and transwell migration assay in HT29 cells and controls untreated or treated with 1 μg/ml rhIGFBP-rP1 and/or 10 ng/ml TGF-β1. The results were shown as mean+S.D. from triplicate experiments
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4385937&req=5

fig6: IGFBP-rP1 blocks TGF-β1-induced EMT in HT29 cells. (a) HT29 cells were incubated with TGF-β1 (10 ng/ml) for the indicated times. The levels of P-smad2/3 were assessed by western blot. (b) Expression of EMT markers assessed by western blot. (c) TGF-β1 promoted cell migration determined by transwell migration assay. The results were shown as mean+S.D. from triplicate experiments. (d, e) Western blot of the indicated antibodies and transwell migration assay in HT29 cells and controls untreated or treated with 1 μg/ml rhIGFBP-rP1 and/or 10 ng/ml TGF-β1. The results were shown as mean+S.D. from triplicate experiments
Mentions: The relevance of the pathway was next examined in HT29 colorectal cancer cells. Here, addition of TGF-β1 induced a time-dependent increase of phosphorylated Smad2/3 protein levels, with 24 h TGF-β having the maximal activation effect in HT29 cells (Figure 6a). In response to TGF-β1 stimulation for 24 h, although the level of E-cadherin showed no apparent change, HT29 cells underwent EMT as determined by downregulation of the epithelial marker ZO-1 with concomitant upregulation of MMP9 and Snail (Figure 6b) as well as increased cell migration (Figure 6c). These data suggested that we had not only established the classical model of TGF-β1-induced EMT, but that it also activated the TGF-β/Smad cascade in HT29 cells. To further evaluate whether IGFBP-rP1 reversed TGF-β1-induced EMT-related changes, we performed a rescue experiment by adding exogenous rhIGFBP-rP1 protein. Consistent with our findings in the other cell lines, treatment with rhIGFBP-rP1 alone decreased TGF-β receptor and phospho-Smad2/3 expression levels as well as inhibited EMT program (Figure 6d, lane 2). This was accompanied by an obvious decrease of HT29 cells invasive ability (Figure 6e, lane 2). Treatment with TGF-β alone activated EMT program, TGF-β receptors, and its downstream molecules (Figure 6d, lane 3). Of note, exogenous rhIGFBP-rP1 protein decreased the activation of TGF-β signaling and restored the upregulation of TGF-β1-induced EMT-related markers (Figure 6d, lane 4 compare with lane 3). Accordingly, rhIGFBP-rP1 decreased the promotion of migration triggered by TGF-β1 (Figure 6e). These data collectively provide evidence that IGFBP-rP1 suppresses EMT by attenuation of TGF-β/Smad signaling in colorectal cancer.

Bottom Line: Cooperation of transforming growth factor-β (TGF-β) and other signaling pathways, such as Ras and Wnt, is essential to inducing EMT, but the molecular mechanisms remain to be fully determined.Here, we reported that insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1), a potential tumor suppressor, controls EMT in colorectal cancer progression.Moreover, we demonstrated that IGFBP-rP1 suppresses EMT and tumor metastasis by repressing TGF-β-mediated EMT through the Smad signaling cascade.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Pathology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China [2] Key Laboratory of Disease Proteomics of Zhejiang Province, Hangzhou, Zhejiang, China.

ABSTRACT
Epithelial-mesenchymal transition (EMT) was initially recognized during organogenesis and has recently been reported to be involved in promoting cancer invasion and metastasis. Cooperation of transforming growth factor-β (TGF-β) and other signaling pathways, such as Ras and Wnt, is essential to inducing EMT, but the molecular mechanisms remain to be fully determined. Here, we reported that insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1), a potential tumor suppressor, controls EMT in colorectal cancer progression. We revealed the inhibitory role of IGFBP-rP1 through analyses of clinical colorectal cancer samples and various EMT and metastasis models in vitro and in vivo. Moreover, we demonstrated that IGFBP-rP1 suppresses EMT and tumor metastasis by repressing TGF-β-mediated EMT through the Smad signaling cascade. These data establish that IGFBP-rP1 functions as a suppressor of EMT and metastasis in colorectal cancer.

Show MeSH
Related in: MedlinePlus