Overexpression of both HER2 and WASF3 in non-metastatic MCF7 breast cancer cells promotes invasion and metastasis more significantly than either gene alone.
In our survey of breast cancer cells, we now demonstrate that exposure to hypoxic conditions increases WASF3 expression levels in MDA231, SKBR3 and MCF7 cells.
An inverse correlation was demonstrated between expression levels of WAVE3 and miR-31 in invasive versus noninvasive breast cancer cell lines. miR-31 directly targeted the 3'-UTR of the WAVE3 mRNA and inhibited its expression in the invasive cancer cells, i.e., miR-31-mediated down-regulation of WAVE3 resulted in a significant reduction in the invasive phenotype of cancer cells.
The high incidence of allelic losses at the D13S263 microsatellite, located distal to both the BRCA2 and the Brush-1 loci but proximal to the retinoblastoma gene, possibly indicates the presence of an additional tumour suppressor gene which may be involved in male breast carcinomas.
This differential loss of Brush-1 mRNA expression for both primary tumors and breast cancer cell lines is the expected pattern for a breast tumor suppressor gene.