Reduction in miR‐141 is Induced by Leukemia Inhibitory Factor and Inhibits Proliferation in Choriocarcinoma Cell Line JEG‐3

PROBLEM: Starting from the peri-implantation period, leukemia inhibitory factor (LIF) is a major regulator of trophoblast functions. Micro-RNAs (miRNA) are short non-coding RNA sequences, which regulate expression of genes at post-transcriptional level. The influence of LIF on miRNA expression in trophoblastic cells has not yet been analyzed and was focus of this investigation. METHOD OF STUDY: JEG-3 choriocarcinoma cells have been stimulated with LIF for 1, 2, 4, 6, and 24 hr. The expression of miR-9, miR-141, miR-21, miR-93, and let-7 g has been analyzed by real-time PCR. Subsequently, miR-141 has been silenced and over-expressed to test its role in the proliferation of JEG-3 cells after 24 and 48 hr. RESULTS: MiR-141 has been significantly downregulated by more than 50% after LIF stimulation, while miR-21 and miR-93 expression has been significantly upregulated. Silencing of miR-141 completely inhibited the proliferation of JEG-3 cells, while over-expression had no effect. CONCLUSION: LIF regulates expression of miRNA in trophoblastic cells, which may be responsible for several functional effects induced by LIF.