Uterine leiomyosarcoma is a severe neoplasia resistant to conventional therapies. In previous studies, we have shown that human SK-UT-1 (ATCC HTB114) uterine leiomyosarcoma cell line secretes nerve growth factor (NGF) and expresses its receptors tyrosine kinase A receptor (TrKA) and low affinity nerve growth factor receptor (p75NTR). Furthermore, we have demonstrated that direct chemical inhibition or IgG neutralization of TrKA receptor induce apoptosis through p75NTR. In the present study, HTB114 cells were exposed to the phosphoinositide 3-kinase (PI3K) inhibitor LY294002 with and without β-NGF: apoptosis, cell cycle, activation of caspase-3 and protein kinase B (AKT) and TrKA/p75NTR phenotypic expression were evaluated. According to the type of exposure, LY294002 not only induced a relevant increase in apoptosis, but also produced a novel and unexpected phenotypic modulation of the NGF receptors with a downregulation of TrKA and an upregulation of p75NTR. This latter increase enhanced HTB114 apoptosis. Our study confirms that the interference on NGF transduction is a promising therapeutical approach in uterine leiomyosarcoma.
Keywords: HTB114; LY294002; PI3K; nerve growth factor; p75NTR; tyrosine kinase A receptor.