Expression of Progesterone Receptor Membrane Component 1 (PGRMC1), Progestin and AdipoQ Receptor 7 (PAQPR7), and Plasminogen Activator Inhibitor 1 RNA-Binding Protein (PAIRBP1) in Glioma Spheroids In Vitro.

Juraj Hlavaty,Ingrid Miller,Reinhard Ertl,Cordula Gabriel

doi:10.1155/2016/8065830

Abstract

Objective. Some effects of progesterone on glioma cells can be explained through the slow, genomic mediated response via nuclear receptors; the other effects suggest potential role of a fast, nongenomic action mediated by membrane-associated progesterone receptors. Methods. The effects of progesterone treatment on the expression levels of progesterone receptor membrane component 1 (PGRMC1), plasminogen activator inhibitor 1 RNA-binding protein (PAIRBP1), and progestin and adipoQ receptor 7 (PAQR7) on both mRNA and protein levels were investigated in spheroids derived from human glioma cell lines U-87 MG and LN-229. Results. The only significant alteration at the transcript level was the decrease in PGRMC1 mRNA observed in LN-229 spheroids treated with 30 ng/mL of progesterone. No visible alterations at the protein levels were observed using immunohistochemical analysis. Stimulation of U-87 MG spheroids resulted in an increase of PGRMC1 but a decrease of PAIRBP1 protein. Double immunofluorescent detection of PGRMC1 and PAIRBP1 identified the two proteins to be partially colocalized in the cells. Western blot analysis revealed the expected bands for PGRMC1 and PAIRBP1, whereas two bands were detected for PAQR7. Conclusion. The progesterone action is supposed to be mediated via membrane-associated progesterone receptors as the nuclear progesterone receptor was absent in tested spheroids.

Highlights

Glioblastoma multiforme (GBM, grade IV astrocytoma) is the most common and most aggressive malignant primary brain tumor in adults [1]
The morphological analysis revealed differences in spheroid size, with spheroids grown from U-87 MG cells being 2.6–4.2-fold larger than those from LN-229 cells (Figures 1(a) and 1(c))
In the U-87 MG spheroids positive cells were counted in the periphery and an increased number of proliferative active cells were determined in the core of these spheroids after stimulation with 3 ng/mL P

Summary

Introduction

Glioblastoma multiforme (GBM, grade IV astrocytoma) is the most common and most aggressive malignant primary brain tumor in adults [1]. In 2015, Atif et al identified the steroid hormone progesterone as potential promising therapeutic agent in GBM [8]. Progesterone was already known to have beneficial effects on the outcome of brain injuries accompanied with cerebral edema and inflammation [9] and known to feature dose-dependent antiproliferative and proapoptotic effects in other tumors including breast, ovarian, and endometrial cancer [10, 11]. These effects were observed and documented, the background of progesterone

Methods

Results

Discussion

Conclusion