胰腺癌Panc-1细胞TFPI-2基因甲基化状态与其体内体外侵袭能力的关系

目的:探讨甲基化酶抑制剂5-氮杂-2'-脱氧胞苷(5-aza-2-deoxycytidine,5-Aza-dC)对胰腺癌Panc-1细胞体内体外侵袭能力及裸鼠皮下移植肿瘤组织TFPI-2基因甲基化状态及表达的影响.方法:用不同浓度的5-Aza-dC处理胰腺癌Panc-1细胞.Transwell法测定各组Panc-1细胞的体外侵袭能力.将用药物处理过的各组Panc-1细胞分别接种于裸鼠皮下,观察各组成瘤率及肿瘤大小.用MSP及RT-PCR检测裸鼠移植瘤组织TFPI-2基因甲基化状态及TFPI-2基因mRNA表达情况.结果:与对照组相比,药物处理组Panc-1细胞体外侵袭能力明显下降,裸鼠成瘤率明显降低,第八周时,肿瘤体积明显低于对照组(P<0.05).与对照组相比,TFPI-2基因异常甲基化状态在药物处理组裸鼠移植瘤组织中得到逆转,药物处理组移植瘤TFPI-2基因mRNA重新表达,并呈剂量依赖性(P<0.05).结论:甲基化酶抑制剂5-氮杂-2'-脱氧胞苷可能在一定程度上抑制人胰腺癌Panc-1细胞系的体内体外侵袭和生长能力,其机制可能与逆转TFPI-2基因高甲基化状态从而恢复其表达有关.

Effect of 5-Aza-dC on the invasion of human pancreatic cancer cell line in vitro and in vivo and effect of 5-Aza-dC on the expression and methylation of TFPI-2 gene in Panc-1 cell line

Objective:To investigate the effects of 5-Aza-2-deoxycytidine(5-Aza-dC) on the invasion of human pancreatic cancer Panc-1 cell line in vitro and vivo,and investigate the effects on the expression and metheylation of TFPI-2 gene in nude mice which loaded human pancreatic cancer cells treated by 5-Aza-dC.Methods: Treated Panc-1 cell line with differernt dosages of 5-Aza-dC.Transwell Chamber method was used to detect the invasion behavior of Panc-1 cell line in vitro after treated with 5-Aza-dC.The Panc-1 cell line treated with different dosages of 5-Aza-dC were implanted into nude mice to observe its growth and metastasis in vivo.TFPI-2 gene DNA,mRNA of carcimoma tissues in nude mice were determined by MSP,RT-PCR.Results: The number of experiment groups to traverse a Matrigel-coated membrane was obviously decreased compared with control group,the invasion ability was lower than control group in vitro.The incidence rate of forming transplantable tumor in experiment group was lower than control group.In eight weeks,the bulk of transplantable tumor in experiment were smaller than control group.The TFPI-2 gene in nude mice carcimoma tissues hypermethylation effectively caused demethylation by 5-Aza-dC.The expression of TFPI-2 mRNA in carcinoma tissues treated with 5-Aza-dC was recovered.Conclusion: 5-Aza-dC could obviously inhibit the invasion ability of pancreatic cancer cells in vitro and in vivo,which may be because 5-Aza-dC reactivates tumor metastasis.