Apoptosis Of Lung Cancer Cell Induced By Survivin T34A Mutant In Vitro And Experimental Targeting Therapy In Vivo

Part I Apoptosis of lung cancer cell induced by Survivin T34Amutant in vitroOBJECTIVE To study the apoptosis of lung cancer A549 cells inducedby survivin Thr³⁴→ Ala in vitro.METHOD We constructed the 3.1a-Survivin-WT and 3.1a-SurvivinThr³⁴→Ala mutant. We transfected the 3.1a-Survivin-WT (WT),3.1a-Survivin Thr³⁴→Ala (T34A) and 3.1a plasmid into A549 cells throughliposome respectively. Cells were cultured for 72 hours and then weredetected for apoptosis rate through flow cytometry (FCM).RESULTS The apoptosis rate for 3.1a , 3.1a-Survivin-WT, and3.1a-Survivin Thr³⁴→Ala induced cells was 6±2.2%, 14±3.9% and38±7.4% (p<0.01) respectively.CONCLUSION 3.1a-Survivin Thr³⁴→Ala might increase the apoptosisrate in A549 cells. It might have a latent target therapeutic effect for lungcancer.Part II Experimental targeting therapy of lung cancer in vivo usingsurvivin T34A mutantOBJECTIVE To study the therapeutic effect of Survivin Thr³⁴→Ala on solid lung cancer in nude mice.METHOD We set up a nude mice model carring A549 cells. When the tumor grew up to 5 mm in diameter, we selected 40 mice and randomized them into 4 groups with 10 mice in each group. We injected 3.1a, 3.1a-Survivin-WT (WT), 3.1a-Survivin Thr³⁴→Ala (T34A) plasmid or cisplatin into the tumor respectively. We measured the tumor on the day of administration and every 5 days later till the 15^th day. We drew the growth curve of the tumor and compared among the groups. All the nude mice were killed with tumors resected on the 15^th day. Routine pathological section and immunohistochemistry staining as well as TUNEL staining were performed for every specimen. We accounted the positive cells and compared the difference among the groups. RESULTS Compared with control groups, tumors in survivin T34A and cisplatin groups grew more slowly and had a statistically significance (p<0.05). Under survivin immunohistochemistry stanining, the positive cells rate in WT group was highly statistically more than blank group(p<0.001), while T34A group statistically more than blank group(p=0.001). Under TUNEL staining, no statistically significance was seen between WT and blank group(p=0.445). There was statistically significance between T34A and blank group(p=0.026). There was also significance between cisplatin and blank group (p=0.013). CONCLUSION Survivin T34A might inhibit A549 tumors growing invivo. Survivin WT and Survivin T34A could obviously express in A549 tumors after transfected with liposome. Survivin T34A might induce apoptosis in A549 cells in vivo with the effect no inferior to cisplatin.