Kameyama S, Kawamata H, Pastan I, Oyasu R
Department of Pathology, Northwestern University Medical School, Chicago, Illinois 60611.
J Cancer Res Clin Oncol. 1994;120(9):507-12. doi: 10.1007/BF01221026.
A protein formed by fusion of transforming growth factor alpha with Pseudomonas exotoxin (TGF alpha-PE40) has been shown to have the ability to kill or inhibit the growth of several carcinoma cell lines. This study was designed to evaluate the in vitro cytotoxic effects of TGF alpha-PE40 on rat and human bladder carcinoma cell lines with different biological potential, and normal rat urothelial cells. The rat cell lines used were D44c, LMC19, and MYU3L, which were established in our laboratory. Human cell lines used were RT4, T24, and 253J. As a normal control, we used the first-passage culture of normal rat bladder urothelium (RU-P1). We examined the number and affinity of epidermal growth factor receptors (EGFR) in these cells, the ability of TGF alpha-PE40 to bind EGFR, and the cytotoxic effect of TGF alpha-PE40 and PE40. Rat cell lines, D44c, LMC19, and MYU3L (EGFR = 4.9 x 10(3)-11.4 x 10(3)/cell) had ED50 values (the concentration of TGF alpha-PE40 needed to reduce the viable cell population by 50%) of 180 pM, 540 pM and 6000 pM respectively; for cI (the concentration required to achieve complete inhibition of growth under continuous serum stimulation) TGF alpha-PE40 concentrations of 10(4) pM, 10(4) pM and higher than 10(4) pM respectively were required. Human cell lines, RT4, T24, and 253J (EGFR = 32 x 10(3)-126 x 10(3)/cell) had ED50 values of 20 pM, 66 pM, and 330 pM respectively and T24 showed cI values of 10(3) pM. RU-P1 (EGFR = 92.6 x 10(3)/cell) had the highest ED50 value of 8000 pM. These data indicate that the susceptibility to TGF alpha-PE40 does not always depend on the number of EGFR, that cells having a relatively small number of EGFR respond well to TGF alpha-PE40, and that normal urothelial cells are more resistant to TGF alpha-PE40 than are cancer cells. The differential effect of TGF alpha-PE40 on normal and neoplastic cells provides a rational basis for its use in vivo to control tumor growth.
一种由转化生长因子α与绿脓杆菌外毒素融合形成的蛋白质（TGFα-PE40）已被证明具有杀死或抑制多种癌细胞系生长的能力。本研究旨在评估TGFα-PE40对具有不同生物学潜能的大鼠和人膀胱癌细胞系以及正常大鼠尿路上皮细胞的体外细胞毒性作用。所用的大鼠细胞系为D44c、LMC19和MYU3L，它们是在我们实验室建立的。所用的人细胞系为RT4、T24和253J。作为正常对照，我们使用了正常大鼠膀胱尿路上皮的第一代培养物（RU-P1）。我们检测了这些细胞中表皮生长因子受体（EGFR）的数量和亲和力、TGFα-PE40与EGFR结合的能力以及TGFα-PE40和PE40的细胞毒性作用。大鼠细胞系D44c、LMC19和MYU3L（EGFR = 4.9×10³-11.4×10³/细胞）的ED50值（使活细胞数量减少50%所需的TGFα-PE40浓度）分别为180 pM、540 pM和6000 pM；对于cI（在持续血清刺激下实现完全生长抑制所需的浓度），分别需要10⁴ pM、10⁴ pM和高于10⁴ pM的TGFα-PE40浓度。人细胞系RT4、T24和253J（EGFR = 32×10³-126×10³/细胞）的ED50值分别为20 pM、66 pM和330 pM，T24的cI值为10³ pM。RU-P1（EGFR = 92.6×10³/细胞）的ED50值最高，为8000 pM。这些数据表明，对TGFα-PE40的敏感性并不总是取决于EGFR的数量，EGFR数量相对较少的细胞对TGFα-PE40反应良好，并且正常尿路上皮细胞比癌细胞对TGFα-PE40更具抗性。TGFα-PE40对正常细胞和肿瘤细胞的不同作用为其在体内用于控制肿瘤生长提供了合理依据。
