TGF-β_1对BCG抗膀胱癌作用的研究

Transforming growth factor β 1 and BCG antitumor mechanism

为了解转化生长因子β１（ＴＧＦβ１）在膀胱癌中的作用机制，采用体外粘附及生长抑制试验观察ＴＧＦβ１通过增加纤维粘连蛋白（ＦＮ）的表达介导ＢＣＧ与肿瘤细胞的粘附及抗肿瘤作用。结果表明：ＴＧＦβ１仅可增加ＢＣＧ对低表达ＦＮ的２５３Ｊ细胞的粘附及细胞毒性作用，而对高表达ＦＮ的６４７Ｖ细胞无明显影响，这一结果与其调节ＦＮ表达相一致。结果提示：ＴＧＦβ１可能通过增加ＦＮ的表达对ＢＣＧ的抗肿瘤作用产生潜在的影响。

As the binding of BCG to fibronectin(FN) is a necessary step in the development of an antitumor response after the intravesical instillation of BCG for bladder cancer, FN expression of tumor cells, TGF β, might be involved in BCG attachment to tumor cells and its antitumor activity. In the present study, we used two transitional carcinoma cell lines with different FN expression and compared BCG/ 3H thymidene labelled BCG adherence and its cytotoxity to the two lines in vitro prior to and after TGF β 1 induction of FN expression. We also observed the changes of tumor cells by electron microscopy. TGF β 1 induction demonstrated dose dependent effect on BCG adherence and cytotoxity to 253J cells only. The maximal effect was observed at 5ng/ml TGF β 1 which is in agreement with FN expression induced by TGF β 1 in prior studies. These findings suggested that TGF β 1 may potentiate BCG antitumor efficacy by promoting FN expression.