摘要
目的ＴＮＦ存在两种形式，目前研究集中于分泌型ＴＮＦ（ｓ－ＴＮＦ），对跨膜型ＴＮＦ（ＴＭ－ＴＮＦ）的研究很少，但仅有的资料表明，ＴＭ－ＴＮＦ较ｓ－ＴＮＦ有更广的杀瘤谱，故本实验拟初步探讨两型ＴＮＦ杀瘤效应的差异。方法应用生物活性测定法检测两型ＴＮＦ的胞毒作用，ＲＴ－ＰＣＲ检测靶细胞ＴＮＦＲｍＲＮＡ表达水平，ＤＮＡ梯带、ＴＵＮＥＬ和Ｓｕｂ－Ｇ１峰检测细胞凋亡，所得结果全部采用ｔ检验。结果ＴＭ－ＴＮＦ不仅能杀伤ｓ－ＴＮＦ敏感细胞株，而且能有效杀伤ｓ－ＴＮＦ耐受细胞（ＨＬ－６０，Ｋ５６２，ＨｅｐＧ２，Ｒａｊｉ）（Ｐ＜０．０１）；ＲＴ－ＰＣＲ检测试验所用的６株靶细胞，其中３株为ＴＮＦＲⅠ单表达（Ｌ９２９，ＭＣＦ－７和ＨｅｐＧ２），２株为ＴＮＦＲ双表达（ＨＬ－６０和Ｋ５６２），１株为ＴＮＦＲⅡ单表达（Ｒａｊｉ）；ｓ－ＴＮＦ敏感细胞单表达ＴＮＦＲⅠ，ＴＭ－ＴＮＦ可杀伤表达任何类型ＴＮＦＲ的细胞；ＴＭ－ＴＮＦ以诱导细胞凋亡为主（Ｐ＞０．０１），ｓ－ＴＮＦ以诱导坏死为主（Ｐ＜０．０１）。结论两型ＴＮＦ的胞毒作用存在显著性差异，由于ＴＭ－ＴＮＦ在局部发挥作用且以诱导凋亡为主，杀瘤谱较ｓ－ＴＮＦ更广，故在肿瘤治疗中可能优于ｓ－Ｔ?
Objective There are two forms of TNF alpha,mainly secreted TNF (s TNF) and transmembrane TNF alpha(TM TNF).It has been shown that TM TNF has a broader cytotoxic spectrum than s TNF.So this study is decided to find the mechanism responsible for this difference. Methods The cytotoxic effect of these two forms of TNF alphas were compared by bioassay. The expression of TNFR mRNA is detected by RT PCR.Differentiation of cell death modes is by DNA ladder,TUNEL and FACS. Results The s TNF alpha has been shown to kill only two of the cell lines while TM TNF alpha has been found to efficiently exert its cytotoxic activity on all of the tested cell lines.3 of 6 cell lines expressed TNFRⅠmRNA alone(L929,MCF 7 and HepG2),2 of 6 cell lines expressed both of TNFRⅠ/Ⅱ(HL 60 and K562),the remaining one expressed TNFRⅡ alone (Raji).s TNF sensitive cell lines expressed TNFRⅠ,while TM TNF can kill target cell lines disregarding which type of surface TNFR was expressed.It was revealed that TNF α could induce both apoptic and necrotic forms of cell death.TM TNF α did result in mainly apoptosis,but sTNF α mostly necrosis. Conclusion There are differnces between these the cytotoxic effects induced by the two forms of TNF alpha.Since TM TNF has a broader cytocidal spectrum, induced apoptosis chiefly and shown effect locally,it may be used better and broaderly than s TNF in the field of tumor therapy.
出处
《中华微生物学和免疫学杂志》
CAS
CSCD
北大核心
1998年第6期499-504,共6页
Chinese Journal of Microbiology and Immunology
基金
国家自然科学基金
