The S100A4 protein as well as the matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are associated with diseases such as arthritis and cancer. This mini review focuses on in vitro and in vivo studies indicating S100A4 involvement in regulation of MMPs and TIMPs, and the biological and pathobiological consequences of this regulation.

The aim of this study was to explore the impact of tumor stroma on invasiveness and expression of gelatinases in xenograft carcinomas. Xenograft tumors of various human carcinoma cells were established either in the tongue or the skin of BALB/c Nude mice. Cell lines originating from oral and skin SCCs were used, as well as a cell line foreign to both organs. Gelatinolytic activity in the tumors was investigated by a novel in situ zymography technique which enables high image resolution. In vivo and in vitro expression of various proteolytic enzymes were analyzed at transcriptional and protein level using RT-qPCR, immunohistochemistry, Western blotting and SDS-PAGE substrate zymography. Tongue tumors showed an invasive growth pattern, whereas the skin tumors established from the same cell lines were non-invasive. Although the repertoire of proteolytic enzymes differed between the cell lines, the tongue tumors of all cell lines showed strong gelatinolytic activity, especially at the invasive front. In contrast, the skin tumors showed only weak gelatinolytic activity. Our results suggest that invasiveness as well as activity of proteolytic enzymes in the tumors is more dependent on the tumor microenvironment than on inherent properties of the cancer cells. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 543.