7045

TGFBI

transforming growth factor, beta-induced, 68kDa;TGFBI;transforming growth factor, beta-induced, 68kDa

RGD-CAP|RGD-containing collagen-associated protein|beta ig-h3|kerato-epithelin|transforming growth factor, beta-induced, 68kD|transforming growth factor-beta-induced protein ig-h3

5q31

protein-coding

Controversy has arisen as to the role of transforming growth factor-beta-induced protein (TGFBI) in the regulation of tumor metastasis. Using lung and breast cancer cell lines (H522 and MCF-7, respectively), we established that TGFBI induced cell adhesion to extracellular matrix proteins by activating adhesion-associated signaling and subsequent structure reformation, ultimately leading to cells less motile; whereas TGFBI reduced abilities of colony formation in soft agar, penetration through matrix gel, and activation of matrix metalloproteinases 2 and 9. Furthermore, injection of TGFBI-expressing cells into immuno-deficient mice resulted in a significant reduction in tumor metastasis in vivo. Taken together, these data suggest that TGFBI moderates the metastatic potential of cancer cells.

metastasis, the major cause of cancer death, is a multistep process that requires interactions between cancer cells and stromal cells and between cancer cells and extracellular matrix. Molecular alterations of the extracellular matrix in the tumor microenvironment have a considerable impact on the metastatic process during tumorigenesis. Here we report that elevated expression of betaig-h3/TGFBI (transforming growth factor, beta-induced), an extracellular matrix protein secreted by colon cancer cells, is associated with high-grade human colon cancers. Ectopic expression of the betaig-h3 protein enhanced the aggressiveness and altered the metastatic properties of colon cancer cells in vivo. Inhibition of betaig-h3 expression dramatically reduced metastasis. Mechanistically, betaig-h3 appears to promote extravasation, a critical step in the metastatic dissemination of cancer cells, by inducing the dissociation of VE-cadherin junctions between endothelial cells via activation of the integrin alphavbeta5-Src signaling pathway. Thus, cancers associated with overexpression of betaig-h3 may have an increased metastatic potential, leading to poor prognosis in cancer patients.

HAb18G/CD147, a new hepatoma-associated antigen cloned and screened from human hepatocellular carcinoma cDNA library, is closely correlated with metastasis process in human hepatoma cells. In the present study we aimed to identify the pivotal molecules of the HAb18G/CD147 signal transduction pathway. The investigation showed that betaig-h3, a secretory extracellular matrix (ECM) protein, was upregulated in HAb18G/CD147-expressing human hepatoma T7721 cells and was downregulated by depressing HAb18G/CD147 expression. The expression of betaig-h3, upregulated in human hepatoma cells, was positively relative to the expression of HAb18G/CD147 in different human hepatoma cell lines. By overexpressing betaig-h3 in human SMMC-7721 hepatoma cells, we discovered that betaig-h3 promoted cell adhesion, invasion, and matrix metalloproteinase (MMP) secretion potential. HAb18G/CD147-induced invasion and metastasis potential of human hepatoma cells can be attenuated by antibodies specific for betaig-h3, and no significant differences on inhibitory effects were observed among T7721 cells incubated with antibodies for betaig-h3 or HAb18G/CD147 or both types together. Taken together, our study suggests that betaig-h3, regulated by the expression of HAb18G/CD147, is involved in the HAb18G/CD147 signal transduction pathway and mediates the HAb18G/CD147-induced invasion and metastasis process of human hepatoma cells.

tumor-produced extracellular matrix (ECM) proteins can be key elements in tumor growth and metastasis. Transforming growth factor beta-inducible (TGFBI) protein is a secreted ECM component that can have dual function in cancer, acting as tumor suppressor or promoter. Although TGFBI is expressed in human melanoma cells, the exact role it might have in melanoma metastasis remains elusive. Assessing the expression and secretion of TGFBI, we show that human metastatic melanomas express and secrete significantly higher amounts of TGFBI, compared with nevus lesions and primary melanoma tumors. Intravenous injection of highly metastatic human melanoma cells expressing shRNA that targets TGFBI assigns a critical role for TGFBI in the formation of melanoma distal metastases in nude mice. In vivo assays demonstrate that TGFBI silencing does not interfere with melanoma cells' dissemination to distal sites but rather with their proliferation and outgrowth within new microenvironment. In line, TGFBI silencing increases melanoma cells motility/invasion/extravasation in vitro but interferes with their progression through the cell cycle, drastically reducing their proliferation. Furthermore, we show that TGFBI is a regulator of cyclins and cyclin-dependent kinases in melanoma. Collectively, our data describe a mechanism of melanoma metastatic outgrowth via promotion of growth/survival by the ECM protein TGFBI.

Oncostatin M, a member of the interleukin-6 family of cytokines, has been implicated in tumorigenesis of human prostate cancer. In the current study, we demonstrate that oncostatin M promotes human adipose tissue-derived mesenchymal stem cell-stimulated tumor growth in an in vivo xenograft transplantation model of the human prostate cancer cell line PC-3M-luc-C6, a PC3M cell line expressing the luciferase gene. Conditioned medium derived from oncostatin M-treated mesenchymal stem cells stimulated adhesion of PC-3M-luc-C6 cells. We identified TGFBI and periostin, extracellular matrix proteins implicated in tumorigenesis and metastasis, as oncostatin M-induced secreted proteins in mesenchymal stem cells. Treatment with oncostatin M stimulated secretion of periostin and TGFBI from mesenchymal stem cells in a time-dependent manner. Immunodepletion of TGFBI and periostin from conditioned medium derived from oncostatin M-treated mesenchymal stem cells resulted in abrogation of adhesion of PC-3M-luc-C6 cells stimulated by oncostatin M-conditioned medium. In addition, small interfering RNA-mediated silencing of TGFBI and periostin resulted in abrogation of cell adhesion stimulated by oncostatin M-conditioned medium. These results suggest that mesenchymal stem cell-derived TGFBI and periostin play a key role in tumorigenesis by stimulating adhesion of prostate cancer cells.

Osteosarcoma, the most common primary bone tumor in children and young adolescents, is characterized by local invasion and distant metastasis. But the detailed mechanisms of osteosarcoma metastasis are not well known. In the present study, we found that betaig-h3 promotes metastatic potential of human osteosarcoma cells in vitro and in vivo. Furthermore, betaig-h3 co-localized with integrin alpha2beta1 in osteosarcoma cells. But betaig-h3 did not change integrin alpha2beta1 expression in Saos-2 cells. Interaction of betaig-h3 with integrin alpha2beta1 mediates metastasis of human osteosarcoma cells. The second FAS1 domain of betaig-h3 but not the first FAS1 domain, the third FAS1 domain or the fourth FAS1 domain mediates human osteosarcoma cells metastasis, which is the alpha2beta1 integrin-interacting domain. We further demonstrated that PI3K/AKT signaling pathway is involved in betaig-h3-induced human osteosarcoma cells metastasis process. Together, these results reveal betaig-h3 enhances the metastasis potentials of human osteosarcoma cells via integrin alpha2beta1-mediated PI3K/AKT signal pathways. The discovery of betaig-h3-mediated pathway helps us to understand the mechanism of human osteosarcoma metastasis and provides evidence for the possibility that betaig-h3 can be a potential therapeutic target for osteosarcoma treatment.