Sulfidefluor 7 AM Interestingly, cells overexpressing DJ-1 attach more on collagen type IV, which is the major ECM component of basement membrane of most tissues and organs in humans. Recent reports have shown that inactivation of DJ-1 by RNAmediated interference resulted in inhibition of the proliferation in leukemia and laryngeal carcinoma cells. Therefore, we next determined whether DJ-1 regulates normal endometrial and endometriotic cell proliferation. Our result demonstrated that over-expression of DJ-1 significantly increases rate of cell proliferation in normal endometrial epithelial cells as well as in stromal cells. Further, inhibition of DJ-1 expression by siRNA resulted in decreased cell proliferation of endometriotic epithelial and stromal cells. Taken together, these results suggest that DJ-1 is also involved in regulation of endometrial and endometriotic cell proliferation. Endometriosis is characterized by migration and invasion of endometrial cells at ectopic sites. This led us to investigate the migration ability of normal endometrial and endometriotic cells. We observed that the endometriotic epithelial cells migrate faster than normal endometrial epithelial cells. On the contrary, no differences in rates of migration between normal endometrial and endometriotic stromal cells were observed. This difference HIOC mightbe due to the inherent nature of these cell types. Since the migration rates of normal endometrial and endometriotic cells are different, we next determined whether DJ-1 is associated with endometrial and endometriotic cell migration as well as invasion potential. Results indicated that overexpression of DJ-1 significantly increases the migrating and invading potential of normal endometrial epithelial cells. Further, inhibition of DJ-1 by siRNA significantly decreased the rate of migration and invasion in endometriotic epithelial cells. Interestingly, we observed that neither over-expression of DJ-1 nor inhibition of DJ-1 affects the migration potential of normal endometrial stromal cells and endometriotic stromal cells, respectively. But, overexpression of DJ-1 leads to an increase in the invading potential of normal endometrial stromal cells. Inhibition of DJ-1 resulted in decrease in invasion potential. These observations suggest that DJ-1 regulates migration and invasion in endometrial and endometriotic epithelial cells but only regulates the process of invasion in stromal cell type.