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DNA methylation-mediated silencing of matricellular protein dermatopontin promotes hepatocellular carcinoma metastasis by α3β1 integrin-Rho GTPase signaling.

Fu Y, Feng MX, Yu J, Ma MZ, Liu XJ, Li J, Yang XM, Wang YH, Zhang YL, Ao JP, Xue F, Qin W, Gu J, Xia Q, Zhang ZG - Oncotarget (2014)

Bottom Line: We demonstrated that DPT was significantly down-regulated in 202 HCC clinical samples and that its expression level was closely correlated with cancer metastasis and patient prognosis.And the inhibitory effects of DPT on HCC cell motility were associated with dysregulated focal adhesion assembly, decreased RhoA activity and reduced focal adhesion kinase (FAK) and c-Src tyrosine kinase (Src) phosphorylation, and all of these alterations required the involvement of integrin signaling.Furthermore, we determined that the inhibitory effects of DPT on HCC cell motility were primarily mediated through α3β1 integrin.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. These authors contributed equally to this work.

ABSTRACT
Dermatopontin (DPT), a tyrosine-rich, acidic matricellular protein, has been implicated in several human cancers. However, its biological functions and molecular mechanisms in cancer progression, particular hepatocellular carcinoma (HCC), remain unknown. We demonstrated that DPT was significantly down-regulated in 202 HCC clinical samples and that its expression level was closely correlated with cancer metastasis and patient prognosis. The overexpression of DPT dramatically suppressed HCC cell migration in vitro and intrahepatic metastasis in vivo. We further revealed that the down-regulation of DPT in HCC was due to epigenetic silencing by promoter DNA methylation. And the inhibitory effects of DPT on HCC cell motility were associated with dysregulated focal adhesion assembly, decreased RhoA activity and reduced focal adhesion kinase (FAK) and c-Src tyrosine kinase (Src) phosphorylation, and all of these alterations required the involvement of integrin signaling. Furthermore, we determined that the inhibitory effects of DPT on HCC cell motility were primarily mediated through α3β1 integrin. Our study provides new evidence for epigenetic control of tumor microenvironment, and suggests matricellular protein DPT may serve as a novel prognostic marker and act as a HCC metastasis suppressor.

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DPT is down-regulated and closely related to patient prognosis in hepatocellular carcinoma (HCC)(A) Relative mRNA expression of DPT, as determined by qPCR, in 36 pairs of HCC tissues and their paracancerous liver (PCL) tissues. Values are means ± SEM (*** P < 0.001). (B) Western blotting analysis of DPT expression in 14 pairs of HCC and PCL. P represents paracancerous liver tissues and H represents HCC tissues. The densitometric analysis of the results was shown below. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was included as a loading control. Values are means ± SEM (*** P < 0.001). (C) Immunohistochemical staining of DPT in HCC and PCL (Original magnification: a, b, e and f, 200x; c, d, g and h, 400x). Scale bars, 10μm. (D) The expression of DPT was down-regulated in 73.23% of the HCC patients. n = 168. (E) Kaplan-Meier analysis of overall survival for the expression of DPT (P = 0.023). (F) Kaplan-Meier analysis of relapse-free survival for the expression of DPT (P = 0.008).
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Figure 1: DPT is down-regulated and closely related to patient prognosis in hepatocellular carcinoma (HCC)(A) Relative mRNA expression of DPT, as determined by qPCR, in 36 pairs of HCC tissues and their paracancerous liver (PCL) tissues. Values are means ± SEM (*** P < 0.001). (B) Western blotting analysis of DPT expression in 14 pairs of HCC and PCL. P represents paracancerous liver tissues and H represents HCC tissues. The densitometric analysis of the results was shown below. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was included as a loading control. Values are means ± SEM (*** P < 0.001). (C) Immunohistochemical staining of DPT in HCC and PCL (Original magnification: a, b, e and f, 200x; c, d, g and h, 400x). Scale bars, 10μm. (D) The expression of DPT was down-regulated in 73.23% of the HCC patients. n = 168. (E) Kaplan-Meier analysis of overall survival for the expression of DPT (P = 0.023). (F) Kaplan-Meier analysis of relapse-free survival for the expression of DPT (P = 0.008).

Mentions: To compare the expression levels of DPT in HCC tissues and their paracancerous liver (PCL) tissues, we performed quantitative real-time polymerase chain reaction (qPCR) for 36 pairs of HCC/PCL tissues and western blotting for 14 pairs of HCC/PCL tissues. The results showed that the DPT expression level was significantly lower in the HCC tissues than in the PCL tissues (Figure 1A and 1B). We further evaluated the expression of DPT in 202 paired HCC and PCL tissues by immunohistochemical staining. Stronger DPT staining was detected in the PCL tissues than in the HCC tissues (Figure 1C). The expression level of DPT was down-regulated in 73.2% of the HCC patients (Figure 1D).


DNA methylation-mediated silencing of matricellular protein dermatopontin promotes hepatocellular carcinoma metastasis by α3β1 integrin-Rho GTPase signaling.

Fu Y, Feng MX, Yu J, Ma MZ, Liu XJ, Li J, Yang XM, Wang YH, Zhang YL, Ao JP, Xue F, Qin W, Gu J, Xia Q, Zhang ZG - Oncotarget (2014)

DPT is down-regulated and closely related to patient prognosis in hepatocellular carcinoma (HCC)(A) Relative mRNA expression of DPT, as determined by qPCR, in 36 pairs of HCC tissues and their paracancerous liver (PCL) tissues. Values are means ± SEM (*** P < 0.001). (B) Western blotting analysis of DPT expression in 14 pairs of HCC and PCL. P represents paracancerous liver tissues and H represents HCC tissues. The densitometric analysis of the results was shown below. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was included as a loading control. Values are means ± SEM (*** P < 0.001). (C) Immunohistochemical staining of DPT in HCC and PCL (Original magnification: a, b, e and f, 200x; c, d, g and h, 400x). Scale bars, 10μm. (D) The expression of DPT was down-regulated in 73.23% of the HCC patients. n = 168. (E) Kaplan-Meier analysis of overall survival for the expression of DPT (P = 0.023). (F) Kaplan-Meier analysis of relapse-free survival for the expression of DPT (P = 0.008).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4196157&req=5

Figure 1: DPT is down-regulated and closely related to patient prognosis in hepatocellular carcinoma (HCC)(A) Relative mRNA expression of DPT, as determined by qPCR, in 36 pairs of HCC tissues and their paracancerous liver (PCL) tissues. Values are means ± SEM (*** P < 0.001). (B) Western blotting analysis of DPT expression in 14 pairs of HCC and PCL. P represents paracancerous liver tissues and H represents HCC tissues. The densitometric analysis of the results was shown below. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was included as a loading control. Values are means ± SEM (*** P < 0.001). (C) Immunohistochemical staining of DPT in HCC and PCL (Original magnification: a, b, e and f, 200x; c, d, g and h, 400x). Scale bars, 10μm. (D) The expression of DPT was down-regulated in 73.23% of the HCC patients. n = 168. (E) Kaplan-Meier analysis of overall survival for the expression of DPT (P = 0.023). (F) Kaplan-Meier analysis of relapse-free survival for the expression of DPT (P = 0.008).
Mentions: To compare the expression levels of DPT in HCC tissues and their paracancerous liver (PCL) tissues, we performed quantitative real-time polymerase chain reaction (qPCR) for 36 pairs of HCC/PCL tissues and western blotting for 14 pairs of HCC/PCL tissues. The results showed that the DPT expression level was significantly lower in the HCC tissues than in the PCL tissues (Figure 1A and 1B). We further evaluated the expression of DPT in 202 paired HCC and PCL tissues by immunohistochemical staining. Stronger DPT staining was detected in the PCL tissues than in the HCC tissues (Figure 1C). The expression level of DPT was down-regulated in 73.2% of the HCC patients (Figure 1D).

Bottom Line: We demonstrated that DPT was significantly down-regulated in 202 HCC clinical samples and that its expression level was closely correlated with cancer metastasis and patient prognosis.And the inhibitory effects of DPT on HCC cell motility were associated with dysregulated focal adhesion assembly, decreased RhoA activity and reduced focal adhesion kinase (FAK) and c-Src tyrosine kinase (Src) phosphorylation, and all of these alterations required the involvement of integrin signaling.Furthermore, we determined that the inhibitory effects of DPT on HCC cell motility were primarily mediated through α3β1 integrin.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China. These authors contributed equally to this work.

ABSTRACT
Dermatopontin (DPT), a tyrosine-rich, acidic matricellular protein, has been implicated in several human cancers. However, its biological functions and molecular mechanisms in cancer progression, particular hepatocellular carcinoma (HCC), remain unknown. We demonstrated that DPT was significantly down-regulated in 202 HCC clinical samples and that its expression level was closely correlated with cancer metastasis and patient prognosis. The overexpression of DPT dramatically suppressed HCC cell migration in vitro and intrahepatic metastasis in vivo. We further revealed that the down-regulation of DPT in HCC was due to epigenetic silencing by promoter DNA methylation. And the inhibitory effects of DPT on HCC cell motility were associated with dysregulated focal adhesion assembly, decreased RhoA activity and reduced focal adhesion kinase (FAK) and c-Src tyrosine kinase (Src) phosphorylation, and all of these alterations required the involvement of integrin signaling. Furthermore, we determined that the inhibitory effects of DPT on HCC cell motility were primarily mediated through α3β1 integrin. Our study provides new evidence for epigenetic control of tumor microenvironment, and suggests matricellular protein DPT may serve as a novel prognostic marker and act as a HCC metastasis suppressor.

Show MeSH
Related in: MedlinePlus