Objective To study the mechanism that glial cell line-derived neurotrophic factor (GDNF)promotes human glio-ma cells proliferation.Methods We divided glioma samples into two groups,including low-grade glioma group and high-grade glio-ma group,while cerebral contusion patients were treated as the control group,12 cases in each group.C6 glioma cell lines were di-vided into three groups,such as GDNF group,BSA(bovine serum albumin)group and control group.CCK-8 (cell counting kit-8) was used to detect the cell proliferation,while Western blot was used to detect the expression of AKT,p-AKT,β-catenin and p-β-catenin in each group.Results Comparing with the control group,the expression levels of AKT,p-AKT,β-catenin and p-β-catenin in glioma group had a significantly increased (P <0.05).Meanwhile,the high-grade gliomas group also had a significant increase in those more than low-grade gliomas group (P <0.05).CCK-8 test showed that the cell proliferation in GDNF group was significant-ly higher than the control group (P <0.05),and the expression levels of p-AKT,β-catenin and p-β-catenin proteins all had a signifi-cant increase (P <0.05).However,the expression level of AKT had no obvious difference.Conclusion GDNF might promote the proliferation of glioma cells by up-regulating the expression of p-AKT,β-catenin and p-β-catenin.

Objective To observe the expression pattern of caspase-3 and HCLS1-associated protein X-1 (HAX-1) at different time after cerebral contusion in rat, and explore the new method for estimating the injury interval. Methods The cerebral contusion model was established using adult SD male rats. Then the rats were randomly allocated into 8 groups: 2 h, 6 h, 12 h, 1 d, 3 d, and 7 d after cerebral con-tusion, sham-operation and normal control. Expression of caspase-3 and HAX-1 protein after cerebral contusion in rat was detected by Western blotting. Laser scanning confocal microscope was used to ob-serve the number of HAX-1 positive cells and TUNEL-stained cells after cerebral contusion. Results The expression of caspase-3 increased parallelly with the time after cerebral contusion and reached the peak value on 3 d. The expression of caspase-3 decreased gradually and still maintained a high level expression on 7 d (P<0.05). The expression of HAX-1 positive cell went up after injury, and reached the peak value at 6 h (P<0.05), then turned down gradually after 12 h and went out of detection after 3 d. The number of TUNEL-stained cells increased obviously at 2 h and reached the peak value on 3 d. The number of TUNEL-stained apoptotic cells decreased gradually and still maintained a high level expres-sion on 7 d (P<0.05). Conclusion The expression of caspase-3 and HAX-1 after cerebral contusion has time sequential regularity, which may provide new evidence for forensic diagnosis of cerebral contusion interval.

Objective To evaluate the effect of ultra short-term low-dose gamma knife radiation on invasive properties of glioma cells at the genetic level.Methods Malignant glioma cell lines U87 and U251 were treated with gamma knife radiation,respectively,with a marginal doses of 0,4,6,8 and 10 Gy (all to the 80％ isodose line).Real time-PCR was used to measure the mRNA expressions of AKT-1,AKT-2,β-catenin and TCF-4 at 30 min after radiation.Results The expressions of AKT-1,AKT-2,β-catenin,TCF-4 in glioma cell lines after low-dose gamma knife radiation with a marginal dose of 6-8 Gy were significantly increased as compared with those after 0 Gy (P＜0.05); reduced expressions ofAKT-1,AKT-2,β-catenin and TCF-4 after a marginal dose of 10 Gy were found as compared with those after 0 Gy (P＜0.05); the β-catenin and AKT-1 mRNA expressions in U87 cells and TCF-4,AKT-1 and AKT-2 mRNA expressions in U251 cells enjoyed the most obvious increase at a marginal dose of 6 Gy; the TCF-4 and AKT-2 mRNA expressions in U87 cells and β-catenin mRNA expression in U251 cells enjoyed the most obvious increase at a marginal dose of 8 Gy.Conclusion Low-dose gamma knife radiation (6-8 Gy) could increase the β-catenin,TCF-4,AKT-1 and AKT-2 expressions,while high dose (10 Gy) could inhibit these effects in a short time period of 30 min.