p27kip1 overexpression regulates VEGF expression, cell proliferation and apoptosis in cell culture from eutopic endometrium of women with endometriosis

We hypothesized that p27kip1 overexpression can regulate endometriosis cell proliferation, apoptosis and vascular endothelial growth factor (VEGF) expression in the endometrium. The overexpression of p27kip1 was obtained by transduction of p27kip1 in primary cultures of endometrium obtained from women with endometriosis tissue with gene therapy technology. First generation bicistronic adenovirus: AdCMVhp27IRESEGFP (Adp27) and AdCMVNull (AdNull) were engineered in order to induce p27kip1 expression in endometrial cells primary culture. The effect of p27kip1 overexpression was elucidated through the cell proliferation evaluation and the expression of the cell cycle-related proteins p16, p21, p27, and p53. Cell cycle and apoptosis in endometrial cells from women with and without endometriosis were also evaluated. The VEGF levels were evaluated 1 and 7 days after transduction. The experiments were performed using Immunofluorescence stainings and flow cytometry technique. The cell proliferation statistically diminished markedly following p27kip1 overexpression in the endometriosis group. This process was accompanied, however, by a statistically significant modulation of the cell cycle-related proteins p16, p21, p27 and p53 markedly increase following p27kip1 overexpression in the endometriosis group (p < 0.001) and an increase in apoptotic cells was observed. In the endometriosis group, significant downregulation of VEGF expression was observed 7 days after p27kip1 overexpression, attaining levels strikingly similar to those observed in the control endometrial cells. The findings of this study showed a link between the cell cycle control protein (p27kip1) and angiogenesis (VEGF). Our results, also reinforces the background of endometrial dysfunction as part of the origin of endometriosis. We believe that better knowledge of endometrium milieu and the establishment of the link between different, previously describe, altered pathways in this tissue can facilitate future genetic cell therapy.