U87MG and U251MG glioblastoma cells are sensitive to TMZ induced senescence.

<p>T98G, U118MG, U251MG and U87MG cells were treated with TMZ [100μM] for 3 h, and then cultured in medium containing 10% FCS. The cells were subsequently subjected to a time-course cell senescence assay. The cells were fixed every 24 h and the cell senescence rate was analyzed by beta-gal assay. U87MG cells were observed to be the most sensitive cell line to TMZ, as the percentage of senescence increased already 24 h after TMZ treatment. The U251MG cells responded more slowly, and started to undergo senescence about 48 h after the treatment. In contrast, the T98G and U118MG cells were insensitive to TMZ induced senescence (A). The expression of MGMT in the four glioblastoma cell lines was determined by using both Q-RT-PCR and Western blotting. MGMT was highly expressed in T98G and U118 cells, but undetectable in U251MG and U87MG cells (B, C). On the basis of 425 primary GBM tumors from TCGA, we calculated the Pearson product-moment correlation coefficient. Bioinformatics analysis revealed that the expression of MGMT does not correlate with the expression of either NTN4 (r value=0.041) or ITGB4 (r value=0.043) (D). Mean ± SE, <i>n</i> ≥ 3.