Growth supressive effect of antisense-AKT2 constructs on proliferation and apoptosis in C6 gliomas : An in vitro and in vivo study

Objective To investigate the effect of anti-sense serine /threonine protein kinase 2 (AKT2) constructs on proliferation and apoptosis of glioma cells. Methods Rat C6 glioblastoma cells were transfected with AS-AKT2 constructs,the expression of AKT2 in cells were identified by in situ hybridization and Western blotting. Proliferative activitiy of glioma cell was evaluated by MTT method and PCNA positive rate, and apoptotic cells were detected by Apoptotic Index (AI) using TUNEL method. Parental C6 cells and C6 cells trasfected with AS-AKT2 cDNA were implanted stereotactically into the right caudate nucleus of SD rats as control and transfected group. Rats with well-established cerebral gliomas were treated with AS-AKT2 cDNA and LXSN empty vector as treated and LXSN group. The dynamic MRI and histopathological changes of the tumors and the expression of AKT2 and PCNA were investigated, apoptosis in glioma cells was examined as well. Results Over-expression of AKT2 were identified in mRNA and protein level in parental C6 cells. As compared with C6 cells and LXSN transfected cells, AKT2 expression was inhibited in AS-AKT2 transfected cell,proliferative activities and PCNA positive rate were decreased in AS-AKT2 cells. Nearly no apoptotic cell could be detected in patrental C6 and LXSN transfected cells, whereas AI increased in AS-AKT2. The survival time of rats in AS- AKT2 treated group and transfected group prolonged significantly than control and empty vector group.The expression of AKT2 and PCNA were inhibited in the tumor spacimens of rats in transfected and treated groups while apoptotic cells was increased. Conclusions AKT2 pathway may exert pivotal role in proliferation and anti-apoptosis in glioma cells, AS-AKT2 can prohibit tumor cell proliferation and induce apoptosis, and thus, it can be a good candidate for gene therapy of glioma.