BCL2 and glioblastoma: Furthermore, tetrandrine exhibits pro-apoptotic activity in various glioblastoma cell lines (U87, U251, and GBM 8401/luc2) by increasing the active forms of caspase-3, -8, and -9 [36,38], upregulating Bax, inducing PARP cleavage, and downregulating Bcl-2 [38].