Calpain 2 is required for the invasion of glioblastoma cells in the zebrafish brain microenvironment.

TitleCalpain 2 is required for the invasion of glioblastoma cells in the zebrafish brain microenvironment.
Publication TypeJournal Article
Year of Publication2012
AuthorsLal, S, La Du, J, Tanguay, RL, Greenwood, JA
JournalJ Neurosci Res
Date Published2012 Apr
KeywordsAnimals, Animals, Genetically Modified, Brain Neoplasms, Calpain, Cell Line, Tumor, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Gene Knockdown Techniques, Glioblastoma, Green Fluorescent Proteins, Humans, In Vitro Techniques, Neoplasm Transplantation, Neovascularization, Pathologic, Oligonucleotide Array Sequence Analysis, Proto-Oncogene Protein c-fli-1, RNA, Small Interfering, Tumor Cells, Cultured, Zebrafish

Glioblastoma is an aggressive primary brain tumor with a 5-year survival rate of less than 5%. The ability of glioblastoma cells to invade surrounding brain tissue presents the primary challenge for the success of focal therapeutic approaches. We previously reported that the calcium-activated protease calpain 2 is critical for glioblastoma cell invasion in vitro. Here, we show that expression of calpain 2 is required for the dispersal of glioblastoma cells in a living brain microenvironment. Knockdown of calpain 2 resulted in a 2.9-fold decrease in the invasion of human glioblastoma cells in zebrafish brain. Control cells diffusely migrated up to 450 μm from the site of injection, whereas knockdown cells remained confined in clusters. The invasion study was repeated in organotypic mouse brain tissues, and calpain 2 knockdown cells demonstrated a 2.3-fold lower area of dispersal compared with control cells. In zebrafish brain, glioblastoma cells appeared to migrate in part along the blood vessels of the host. Furthermore, angiogenesis was detected in 27% of zebrafish injected with control cells, whereas only 12.5% of fish receiving knockdown cells showed the formation of new vessels, suggesting a role for calpain 2 in tumor cell angiogenesis. Consistent with the progression of glioblastoma in humans, transplanted tumor cells were not observed to metastasize outside the brain of zebrafish. This study demonstrates that calpain 2 expression is required for the dispersal of glioblastoma cells within the dynamic microenvironment of the brain, identifying zebrafish as a valuable orthotopic system for studying glioblastoma cell invasion.

Alternate JournalJ. Neurosci. Res.
PubMed ID22183788
PubMed Central IDPMC3274595
Grant ListP30 ES000210 / ES / NIEHS NIH HHS / United States
P30 ES000210-38 / ES / NIEHS NIH HHS / United States
R01 GM063711 / GM / NIGMS NIH HHS / United States
P30 ES00210 / ES / NIEHS NIH HHS / United States