A Customisable Cell Line Model of Glioblastoma

Glioblastoma is an extremely malignant brain tumour with one of the lowest survival rates of all cancers. Current treatments do very little to alter this prognosis. Research into new therapies and the biology of glioblastoma has made scarce progress over the past decades. This is partly due to the combination of the tumour’s heterogeneity, and the inability of the current animal models to accurately depict this. This project was a pilot study into the development and characterisation of a novel cell line model of glioblastoma, which could be transplanted into immune competent mice, in order to study the disease.

An immortalised C57BL/6 astrocyte cell line, with an EGFP transgene, was used as the base to add glioblastoma specific mutations. To produce a ‘classical-like’ glioblastoma model, a knockout in Pten was induced, onto which two separate lines the human oncogenes, EGFRVIII and RAS V12, were stably expressed. ‘Secondary-like’ models were created with a knockout of P53, and the stable transfection of IDH1R132H.

The ‘classical-like’ cell lines were assessed for how well they mimicked a classical glioblastoma. The Pten knockout cell line showed an increased proliferative and metabolic rate compared with the astrocytes and a significant increase in clonogenicity. The addition of RAS V12 to the cells showed an increased migratory capacity; and the Pten + EGFRVIII cell line had a tendency towards an increased proliferation. The ‘secondary-like’ cell lines were assessed for their survival-related phenotypes. The P53 cell line showed a decreased proliferative rate, but with an increased metabolic rate and clonogenic ability. The introduction of the IDH1 mutant protein resulted in a decreased rate of G2 arrest in response to ionising radiation.

These cell lines recapitulated what is seen in human glioblastoma tumours and show potential as a transplantation model. Future research will investigate the tumorigenicity of these cell lines.