10516

FBLN5

fibulin 5;FBLN5;fibulin 5

developmental arteries and neural crest EGF-like protein|fibulin-5|urine p50 protein

14q32.1

protein-coding

The tumor microenvironment is now recognized as a major factor in determining the survival and growth of disseminated tumor cells at potential metastatic sites. tumor cells send signals to stroma cells and stimulate them to produce factors that in turn create favorable conditions for tumor cell metastasis. Activated fibroblasts constitute an important component of the tumor-associated stroma. We have previously shown that S100A4 protein produced by stromal fibroblasts in the primary tumor stimulates metastasis formation. Here we show that activated fibroblasts also stimulate the formation of metastases independently of S100A4 expression during organ colonization. To identify genes that could potentially interfere with fibroblast-driven metastasis, we used gene expression profiling of S100A4-deficient fibroblasts treated with and without tumor cell-conditioned media. Five differentially expressed genes encoding cell surface and secreted proteins with potential metastasis-modulating activity were selected. expression of lymphocyte antigen 6 complex (Ly6c) and matrix metalloproteinase 3 (Mmp3) was upregulated in fibroblasts in response to tumor-conditioned medium, whereas expression of cadherin-16 (Cdh16), Ccn2, and fibulin-5 (Fbln5) was downregulated. Further analysis showed that Fibulin-5 is able to suppress the metastatic colonization of lungs and liver. Additional studies suggest a mechanism in which Fibulin-5 suppresses metastasis formation by inhibiting production of matrix metalloproteinase 9 (MMP9) and reducing the invasive behavior of fibroblasts. Together our data are consistent with the notion that tumors secrete factors that downregulate expression of Fbln5 in fibroblasts at sites of metastatic colonization, in turn upregulating Mmp9 expression and stimulating metastatic organ colonization.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is known for its high metastatic potential and locoregional recurrence, although the molecular alterations that are driving NPC metastasis remain unclear at this time. This study aimed to examine the expression of fibulin-5 in NPC, correlate the results with clinicopathological variables and survival, and to investigate the role of fibulin-5 in human NPC cell lines. MATERIAL AND METHODS: Standard semi-quantitative-RT-PCR, quantitative-RT-PCR, immunoblotting, and immunohistochemistry were used to investigate the mRNA and protein expression profiles of fibulin-5 in normal and NPC tissues. Immunohistochemistry of fibulin-5 was correlated with clinicopathological characteristics by univariate analyses. NPC cells overexpressing fibulin-5 or fibulin-5-siRNA cells were generated by stable transfection to characterize the molecular mechanisms of fibulin-5-elicited cell growth and metastasis. RESULTS: Our results demonstrated that fibulin-5 overexpression in NPC specimens and significantly correlated with advanced tumor metastasis indicating a poor 5-year overall survival. Fibulin-5 was mainly expressed in the nucleus in human NPC specimens and cell lines. Functionally, fibulin-5 overexpression yielded fast growth in NPC cells. In addition, fibulin-5 promotes cell metastasis in NPC cells through increased FLJ10540 and phosphor-AKT activity. In contrast, siRNA depletion of fibulin-5 suppressed FLJ10540 expression and phosphor-AKT activity. Suppression of either fibulin-5 or FLJ10540 can cause significant inhibition with regards to cell motility in NPC cells. Finally, immunohistochemical analysis of human aggressive NPC specimens showed a significant and positive correlation between fibulin-5 and FLJ10540 expression. CONCLUSION: Higher fibulin-5 expression is not only an important indicator of poor survival, but also contributes to the development of new therapeutic strategies in the FLJ10540/AKT pathway for NPC treatment.

OBJECTIVE: To investigate the expression of EVEC in ovarian carcinoma and explore its biological significance. METHODS: The expression of EVEC in 22 specimens of normal ovarian tissues and 63 specimens of ovarian cancers was detected by RT-PCR and Western blotting analysis, respectively. RESULTS: RT-PCR showed that the expression level of EVEC in stage I-II ovarian cancer (0.199 +/- 0.014) was significantly higher than that in stage III-IV ovarian cancer (0.155 +/- 0.015, P < 0.05), and significantly lower than that in normal ovarian tissues (0.415 +/- 0.055, P < 0.05). There was no significant difference between the expression levels of EVEC in primary sites and that in corresponding metastatic sites of ovarian cancer (P > 0.05). Furthermore, the results of Western blot also showed that the protein expression level of EVEC in stage I-II ovarian cancer was also significantly lower than that in normal ovarian tissues (0.179 +/- 0.026 vs. 0.543 +/- 0.032, P < 0.05), and higher than that in stage III-IV ovarian cancer (0.179 +/- 0.026 vs. 0.115 +/- 0.023, P < 0.05). The EVEC expression level in the epiploic metastasis of stage I-II ovarian cancer was significantly higher than that of stage III-IV ovarian cancer (0.201 +/- 0.028 vs. 0.101 +/- 0.037, P < 0.05). The expression of EVEC in ovarian carcinoma had no correlation with age, pathologic classification and histological grade (P > 0.05). CONCLUSIONS: EVEC is closely related with carcinoma metastasis. The expression of EVEC in ovarian cancer and its metastatic sites was remarkably decreased. EVEC may play a negative role in the development and metastasis of ovarian cancer and may be a valuable marker in estimation of the prognosis for patients.