Inhibition of TRPM7 by carvacrol suppresses glioblastoma cell proliferation, migration and invasion.

Wen-Liang Chen,Marielle Deurloo,Ekaterina Turlova,James T Rutka,Hong-Shuo Sun,Burton B Yang,Zhong-Ping Feng,Andrew Barszczyk,Baosong Liu

doi:10.18632/oncotarget.3872

Abstract

Glioblastomas are progressive brain tumors with devastating proliferative and invasive characteristics. Ion channels are the second largest target class for drug development. In this study, we investigated the effects of the TRPM7 inhibitor carvacrol on the viability, resistance to apoptosis, migration, and invasiveness of the human U87 glioblastoma cell line.The expression levels of TRPM7 mRNA and protein in U87 cells were detected by RT-PCR, western blotting and immunofluorescence. TRPM7 currents were recorded using whole-cell patch-clamp techniques. An MTT assay was used to assess cell viability and proliferation. Wound healing and transwell experiments were used to evaluate cell migration and invasion. Protein levels of p-Akt/t-Akt, p-ERK1/2/t-ERK1/2, cleaved caspase-3, MMP-2 and phosphorylated cofilin were also detected.TRPM7 mRNA and protein expression in U87 cells is higher than in normal human astrocytes. Whole-cell patch-clamp recording showed that carvacrol blocks recombinant TRPM7 current in HEK293 cells and endogenous TRPM7-like current in U87 cells. Carvacrol treatment reduced the viability, migration and invasion of U87 cells. Carvacrol also decreased MMP-2 protein expression and promoted the phosphorylation of cofilin. Furthermore, carvacrol inhibited the Ras/MEK/MAPK and PI3K/Akt signaling pathways.Therefore, carvacrol may have therapeutic potential for the treatment of glioblastomas through its inhibition of TRPM7 channels.

Highlights

GBM (Glioblastoma Multiforme) is a common primary brain tumor with aggressive proliferative and invasive characteristics; it has a 5-year survival rate of 9.8% in adults that undergo a combination of chemotherapy and radiotherapy [1]
It is for this reason that novel compounds targeting receptor tyrosine kinases (RTKs), vascular endothelial growth factor (VEGF) receptors, the PI3k/Akt/mTOR signaling pathway, and the MAPK signaling pathway are currently being evaluated in clinical trials [7]
Our results provide the first evidence that TRPM7 channels are highly expressed in U87 cells

Summary

Introduction

GBM (Glioblastoma Multiforme) is a common primary brain tumor with aggressive proliferative and invasive characteristics; it has a 5-year survival rate of 9.8% in adults that undergo a combination of chemotherapy and radiotherapy [1]. The median overall survival is only 14.6 months after surgical resection, chemotherapy and radiation, which is due to the rapid proliferation and unrestricted migration of glioblastomas [1]. Genetic abnormalities that enhance receptor tyrosine kinase (RTK)-mediated constitutive activation of Ras/MEK/MAPK and PI3K/Akt signaling pathways have been identified in human glioblastomas [5, 6]. It is for this reason that novel compounds targeting receptor tyrosine kinases (RTKs), vascular endothelial growth factor (VEGF) receptors, the PI3k/Akt/mTOR signaling pathway, and the MAPK signaling pathway are currently being evaluated in clinical trials [7]

Methods

Results

Conclusion