These results suggested that reduced E-cadherin expression combined with higher S100A4 expression is related to a poor prognosis through hematogenous metastasis in pulmonary adenocarcinoma.
S100A4, a small calcium-binding protein belonging to the S100 protein family, is commonly overexpressed in a variety of tumor types and is widely accepted to associate with metastasis by regulating the motility and invasiveness of cancer cells.
The primary tumours arising from the S100A4-expressing cells contained high levels of immunocytochemically-detected S100A4 and this high level of S100A4 and the metastatic potential were maintained when cells from a metastasis were re-injected into syngeneic rats.
These results suggested that reduced E-cadherin expression combined with higher S100A4 expression is related to a poor prognosis through hematogenous metastasis in pulmonary adenocarcinoma.
In a previously published report we characterized the expression of the metastasis-associated proteins S100A4, osteopontin (OPN) and ephrin-A1 in a prospectively collected panel of non-small cell lung cancer (NSCLC) tumors.
Using immunohistochemistry, we found that high levels of S100A4 were detected in 24 of 28 (86%) PTC specimens and their local regional lymph node or distant metastases.
Further multivariate analysis suggested that depth of invasion, lymph node and distant metastases, tumor-node-metastasis (TNM) stage, and upregulation of S100A4 were independent prognostic indicators for the disease.
Furthermore, S100A4 levels were determined because recent reports have suggested a possible association between MMPs, TIMPs, and the metastasis-associated gene S100A4.
High levels of S100A4 were found to significantly correlate with histological grade (P=0.030) and loss of oestrogen receptor (P=0.046), but not to the time interval between surgery and development of distant metastasis (P=0.51) or to patient survival (P=0.89).
We then knocked down of S100A4 expression by RNA interference (S100A4 siRNA) and investigated its effects on growth and metastasis in two human ATC cell lines 8505C (BRAFV600E) and Cal-62 (BRAFwt) in vitro and in vivo.
In metastatic breast cancers, NFAT5 promotes epithelial-mesenchymal transition (EMT) and invasion of cells by switching on the expression of the calcium binding protein S100A4, and facilitates the angiogenesis of breast epithelial cells and thus the development of metastases by transcriptionally activating vascular endothelial growth factor C (VEGF-C).
In addition, the expression of the metastasis-associated gene 18A2/mts1 as well as the tissue inhibitor of metalloproteinases-2 (TIMP-2) was analysed in each of the glioma-derived cell lines.
We found the mRNA and protein levels of S100A4 expression in ESCCs was significantly upregulated, and more importantly, that expression of S100A4 and E cadherin are strongly negatively correlated in patients who had metastasis.
Immune-histochemical analysis of 239 patient tissue samples revealed a correlation of higher CYR61 and S100A4 expression with invasive breast cancer and metastasis.
Using immunohistochemistry, we found that high levels of S100A4 were detected in 24 of 28 (86%) PTC specimens and their local regional lymph node or distant metastases.
S100A4 protein belongs to the S100 subfamily, which has grown to be one of the large subfamilies of the EF-hand Ca(2+)-binding proteins, and overexpression of S100A4 is suggested to associate with cell proliferation, invasion, and metastasis.
Using a panel of genes identified by suppression subtractive hybridization of cDNAs from individual primary tumours and a metastasis, some cDNAs were found to exhibit a differential pattern of expression associated with the expression of S100A4 protein (including osteopontin, S100A9, claudin 2 and several Expressed Sequence Tags sequences).