Is current therapy of malignant gliomas beneficial for patients? Proteomics evidence of shifts in glioma cells expression patterns under clinically relevant treatment conditions.

The most common human brain tumours - gliomas - have poor prognosis with and without treatment. The current therapy conditions act sub-lethally and cannot effectively suppress the proliferation of glioma cells. Here we show differential protein expression patterns in surviving human malignant U87-MG glioma cells under clinically relevant chemo/radiotherapy. In parallel experiments, the cells underwent either irradiation (2 Gy, 200 KV X-ray) or chemotreatment with 30 microg/mL of temozolomide in the cultivation medium or combined chemo/radiation treatment. The cell cultures were treated during 5 days from day 4 until day 9 of growth. Modulated expression patterns of vimentin and RhoA GTPase indicate a potentially increasing grade of malignancy in treated cell fractions correlating well with extremely aggressive tumour phenotypes observed clinically at recidivation of treated malignant gliomas.