A novel antitumor peptide inhibits proliferation and migration and promotes apoptosis in glioma cells by regulating the MKK6/p38 signaling pathway.

Abstract

Protein- or peptide-based therapeutics have emerged as an innovative strategy for the treatment of cancer. Our previous research demonstrated that tripartite motif 9 short isoform (TRIM9s) is a tumor suppressor in glioma. In this report, we investigated whether a new peptide derived from TRIM9s, named T9sP, inhibits glioma progression and determined the possible molecular mechanism. The CCK-8 proliferation assay was performed in LN229 and U251 glioma cells. The scratch-wound assay was used to determine the migration of the cells. Apoptosis was assessed by flow cytometry using Annexin V-FITC/PI double staining method. The relative protein expression levels were detected by immunoblot analysis. The cell-penetrating peptide TAT was fused with T9sP to form TAT-T9sP. TAT-T9sP efficiently penetrated through the cell membrane of both LN229 and U251 cells. TAT-T9sP inhibited proliferation and migration and promoted apoptosis of glioma cells. TAT-T9sP activated p38 signaling by upregulating MKK6, and a p38 inhibitor, SB203580, reversed the inhibitory effects of TAT-T9sP on glioma cells. These results indicated the potential of TAT-T9sP for the development of a new anti-glioma medicine.