The HDM2 (MDM2) Inhibitor NVP-CGM097 Inhibits Tumor Cell Proliferation and Shows Additive Effects with 5-Fluorouracil on the p53-p21-Rb-E2F1 Cascade in the p53wild type Neuroendocrine Tumor Cell Line GOT1.

Neuroendocrinology 2018 21;106(1):1-19. Epub 2016 Nov 21.

Department of Internal Medicine II, Campus Grosshadern, University Hospital, Ludwig Maximilian University of Munich, Munich, Germany.

Background/aims: The tumor suppressor p53 is depleted in many tumor cells by the E3 ubiquitin ligase mouse double minute 2 homolog (MDM2) through MDM2/p53 interaction. A novel target for inhibiting p53 degradation and for causing reexpression of p53wild type is inhibition of MDM2. The small molecule NVP-CGM097 is a novel MDM2 inhibitor. We investigated MDM2 inhibition as a target in neuroendocrine tumor cells in vitro.

Methods: Human neuroendocrine tumor cell lines from the pancreas (BON1), lung (NCI-H727), and midgut (GOT1) were incubated with the MDM2 inhibitor NVP-CGM097 (Novartis) at concentrations from 4 to 2,500 nM.

Results: While p53wild type GOT1 cells were sensitive to NVP-CGM097, p53mutated BON1 and p53mutated NCI-H727 cells were resistant to NVP-CGM097. Incubation of GOT1 cells with NVP-CGM097 at 100, 500, and 2,500 nM for 96 h caused a significant decline in cell viability to 84.9 ± 9.2% (p < 0.05), 77.4 ± 6.6% (p < 0.01), and 47.7 ± 9.2% (p < 0.01). In a Western blot analysis of GOT1 cells, NVP-CGM097 caused a dose-dependent increase in the expression of p53 and p21 tumor suppressor proteins and a decrease in phospho-Rb and E2F1. Experiments of co-incubation of NVP-CGM097 with 5-fluorouracil, temozolomide, or everolimus each showed additive antiproliferative effects in GOT1 cells. NVP-CGM097 and 5-fluorouracil increased p53 and p21 expression in an additive manner.

Conclusions: MDM2 inhibition seems a promising novel therapeutic target in neuroendocrine tumors harboring p53wild type. Further investigations should examine the potential role of MDM2 inhibitors in neuroendocrine tumor treatment.

Download full-text PDF

Source
http://dx.doi.org/10.1159/000453369DOI Listing
January 2019
33 Reads

Publication Analysis

Top Keywords

got1 cells
16
neuroendocrine tumor
16
p53wild type
16
cells nvp-cgm097
12
tumor cell
12
mdm2 inhibitor
12
nvp-cgm097
9
mdm2 inhibition
8
tumor suppressor
8
target neuroendocrine
8
tumor
8
inhibitor nvp-cgm097
8
p53 p21
8
nvp-cgm097 5-fluorouracil
8
tumor cells
8
mdm2
7
cells
7
got1
6
neuroendocrine
5
decline cell
4

Similar Publications