Pyr3 Induces Apoptosis and Inhibits Migration in Human Glioblastoma Cells

Glioblastoma, also known as glioblastoma multiforme (GBM), is a fast-growing type of tumor that is the most aggressive brain malignancy in adults. According to GEO profile analysis, patients with high transient receptor potential canonical 3 (TRPC3) expression have poor survival rates. The aim of this study is to evaluate the effects of Ethyl-1-(4-(2,3,3-trichloroacrylamide)phenyl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate (Pyr3), a selective TRPC3 channel blocker, on the proliferation and migration of human glioblastoma cells.

We first analyzed the TRPC3 mRNA expression in Gene Expression Omnibus (GEO) database. Then, TRPC3 protein expression was analyzed by Western blotting in three human GBM cell lines. The survival rate was measured by sulforhodamine B. JC1 staining was used to analyze the mitochondria membrane potential by flow cytometric analysis. Besides, the migration and invasion were evaluated by wound healing and Transwell assays. Annexin V and 7-aminoactinomycin D staining was used to monitor the apoptosis by flow cytometric analysis. The expression of apoptotic-related and migration-related proteins after Pyr3 treatment was detected by Western blotting. In addition, an orthotropic xenograft mouse model was used to assay the effect of Pyr3 in the in vivo study.

Basis on the results of bioinformatics study, glioma patients with higher TRPC3 expression had a shorter survival time than those with lower TRPC3 expression. GBM cell proliferation was decreased by Pyr3 treatment. The migration and invasion abilities of glioma cells were also inhibited via focal adhesion kinase and myosin light chain dephosphorization after Pyr3 treatment. Moreover, Pyr3 induced caspase-dependent apoptosis and mitochondria membrane potential imbalance in the GBM cells. In a xenograft animal model, Pyr3 in combination with temozolomide (TMZ) inhibited GBM tumor growth.

Pyr3 inhibited GBM tumor growth in vitro and in vivo. Pyr3-TMZ combination therapy could be used to treat glioblastoma in the future.