Inhibition of the mTOR pathway and reprogramming of protein synthesis by MDM4 reduce ovarian cancer metastatic properties

Abstract

Epithelial ovarian cancer (EOC) is a highly heterogeneous disease with a high death rate mainly due to the metastatic spread. The expression of MDM4, a well-known p53-inhibitor, is positively associated with chemotherapy response and overall survival (OS) in EOC. However, the basis of this association remains elusive. We show that in vivo MDM4 reduces intraperitoneal dissemination of EOC cells, independently of p53 and an immune-competent background. By 2D and 3D assays, MDM4 impairs the early steps of the metastatic process. A 3D-bioprinting system, ad hoc developed by co-culturing EOC spheroids and endothelial cells, showed reduced dissemination and intravasation into vessel-like structures of MDM4-expressing cells. Consistent with these data, high MDM4 levels protect mice from ovarian cancer-related death and, importantly, correlate with increased 15 y OS probability in large data set analysis of 1656 patients. Proteomic analysis of EOC 3D-spheroids revealed decreased protein synthesis and mTOR signaling, upon MDM4 expression. Accordingly, MDM4 does not further inhibit cell migration when its activity towards mTOR is blocked by genetic or pharmacological approaches. Importantly, high levels of MDM4 reduced the efficacy of mTOR inhibitors in constraining cell migration. Overall, these data demonstrate that MDM4 impairs EOC metastatic process by inhibiting mTOR activity and suggest the usefulness of MDM4 assessment for the tailored application of mTOR-targeted therapy.

Characterization of Glioblastoma Cells Response to Regorafenib

“…For collagen-embedded spheroids, 2 × 10 3 A172 or 10 3 U87, GSC#1, and GSC#83 were suspended in 20% methylcellulose solution and plated on ULA plates. After 48 h, the spheroids were embedded into collagen matrix as indicated in [ 19 ]. Spheroid area, diameters, and migration distance were measured by ImageJ software.…”

Characterisation of 3D Bioprinted Human Breast Cancer Model for In Vitro Drug and Metabolic Targeting

“…Rapamycin and doxycycline have metabolic rewiring effects; therefore, their effects could be altered completely in 3D structures, where the metabolic activity is known to be variable [74,75]. Other results and studies call for using 3D culturing or in vivo systems to analyse the mTOR inhibitory or other regulatory effects on cellular metabolism [76,77]. In our presented quantitative comparative protein expression analyses, some similarities in cellular metabolic protein expressions in 2D cultures and 3D spheroids were underlined by Wes TM Simple.…”