Lapatinib inhibits meiotic maturation of porcine oocyte-cumulus complexes cultured in vitro in gonadotropin-supplemented medium.

Objective: To determine whether inhibition of epidermal growth factor (EGF) receptor tyrosine kinase with lapatinib affects oocyte maturation, expression of the cumulus expansion-associated genes such as tumor necrosis factor alpha-induced protein 6 (TNFAIP6) and prostaglandin-endoperoxide synthase 2 (PTGS2), and synthesis of hyaluronan (HA) and progesterone (P) by porcine oocyte cumulus complexes (OCC).

Design: Our work focuses on lapatinib, an orally active small molecule that selectively inhibits the tyrosine kinase domain of both EGF receptor and human EGF receptor 2, and downstream signaling.

Setting: A reproductive biology laboratory.

Patient(s): Not applicable.

Intervention(s): Porcine OCC were cultured in vitro in a medium with FSH/LH in the presence/absence of lapatinib.

Main Outcome Measure(s): Methods performed: real-time reverse transcriptase-polymerase chain reaction (PCR), immunofluorescence, RIA.

Result(s): In FSH/LH-stimulated and expanded cumulus oophorus extracellular matrix, HA was detected with biotinylated HA-binding proteins. However, weaker HA- and weaker cytoplasmic TNFAIP6 were detected were detected in lapatinib-pretreated OCC. The expression of the two cumulus expansion-associated gene transcripts was significantly decreased and synthesis of HA by cumulus cells was reduced. Lapatinib (10 μM) inhibited FSH/LH-induced oocyte meiotic maturation. Progesterone production increased after OCC stimulation with FSH/LH and was significantly decreased by lapatinib (10 μM).

Conclusion(s): Lapatinib inhibits oocyte maturation and reduces expression of cumulus expansion-associated transcripts, and synthesis of HA and P in OCC cultured in vitro in FSH/LH-supplemented medium.