Increased insulin-like growth factor 1 activity can rescue KLE endometrial-like cells from apoptosis

Background: The peritoneal fluid (PF) of women with endometriosis contains protease(s) activity able to hydrolyze insulin-like growth factor-binding p rotein 3 (IGFBP-3), increasing the bioavailability of insulin-like growth f actor-1 (IGF-1) locally. Therefore, we characterized the effects of IGF-1 o n KLE endometrial-like cells in vitro. Materials and Methods: The mitogenic effect of IGF-1 was assessed by the an alysis of the DNA content and cell count. Apoptosis was triggered experimen tally by the 48 hr exposure of KLE cells to 100 nM of adriamycin in the pre sence and absence of IGF-1 (50 ng/ml). Adriamycin apoptosis of KLE cells wa s determined by the number of dead KLE cells using trypan blue exclusion an d by the DNA fragmentation on simple agarose gel and flow cytometry of prop idium iodide and HOECHST 33342-stained KLE cells using an EPICS 753 pulse c ytometer. Results: ICE-I stimulated the growth of KLE cells in a dose-dependent manne r (optimal dose of 50 ng/ml) and protected I(LE cells from adriamycin (100 nM)-induced apoptosis. Conclusions: These data suggest that IGF-I is a survival factor for I(LE ce lls. Conceivably, increased IGF-1 activity in the PF can optimize both the survival and ectopic growth of endometrial cells in the peritoneal cavity.