Introduction
Breast carcinoma is the most frequent malignancy occurring in women of Western developed countries (Bray et al. 2004). There are numerous genes that have been demonstrated to have a role in breast cancer. However, more genes need to be assessed in order to determine which genes have the greatest impact on this cancer.
The genes neuropilin-1 (NRP-1) and CC3/TIP30 were examined in this study to see if their expression levels varied between the breast cancer cell lines Sk-Br-3 and T-47D. NRP-1 is a 130 to 140 kDa single spanning transmembrane glycoprotein originally described as a receptor for both semaphorin and vascular endothelial growth factor (Fujiswasa et al. 1995). NRP-1 is up-regulated in a variety of aggressive human cancers including pancreatic (Parirkh et al. 2003) and colon cancer (Parirkh et al. 2004). Therefore, NRP-1 may also be up-regulated in aggressive invasive breast cancer cell lines. While there are some reports of NRP-1 expression in breast cancer, those results differ in the pattern of its expression and have only been tested in a few breast cancer cell lines (Baba et al. 2007).
The human CC3/TIP30 gene is a putative metastasis suppressor gene, based on the results of experimental studies using lung and colon cancer cell lines (Shtivelman 1997). There are at least two mechanisms by which CC3/TIP30 exerts this metastasis suppressing effect. One mechanism that as been shown is that CC3/TIP30 induces apoptosis in v-SCLC cells deprived of growth factors (Shtivelman 1997). Secondly, CC3/TIP30 has been shown to have an angiogenesis-inhibiting effect, since it reduces the expression of certain angiogenic modulators in various tumor cell lines (NicAmhlaoibh and Shtivelman 2001). Due to the ability of CC3/TIP30 to act as a metastasis suppressor it may have a role in the invasiveness of certain cancers, especially breast cancer. However, there are a only a few reports of CC3/TIP30 expression in breast cancer cells (Zhang et al. 2003a, Zhang et al. 2003b), and these studies assess a limited number of breast cancer cell lines.
In this study, I sought to investigate the expression pattern of NRP-1 and CC3/TIP30 in an invasive and noninvasive breast cancer cell line. The two cell lines used in this study were Sk-Br-3 and T-47D. Sk-Br-3 is an invasive breast cancer cell line (Trempe and Fogh 1973) and T-47D is a noninvasive breast cancer cell line. (Keydar et al. 1979). The goal of this study was to examine gene expression of NRP-1 and CC3/TIP30 in the Sk-Br-3 and T-47D cell lines to determine if expression patterns correlated with a particular cell line.
