Transforming growth factor-beta1 is a mediator of androgen-regulated growth arrest in an androgen-responsive prostatic cancer cell line, LNCaP.
Transforming growth factor-beta1 is a mediator of androgen-regulated growth arrest in an androgen-responsive prostatic cancer cell line, LNCaP.
复制标题
DOI：
10.1210/endo.137.3.8603613
复制
发表时间：
1996-03
期刊：
影响因子：
4.8
通讯作者：
Isaac Y. Kim;J. H. Kim;D. Zelner;H. Ahn;H. Ahn;J. Sensibar;Chung Lee
中科院分区：
文献类型：
--
作者：
Isaac Y. Kim;J. H. Kim;D. Zelner;H. Ahn;H. Ahn;J. Sensibar;Chung Lee
LNCaP 是一种雄激素反应性前列腺癌细胞系，对培养物中二氢睾酮 (DHT) 剂量的增加表现出钟形生长反应。尽管对雄激素刺激产生这种生长反应的确切机制尚不清楚，但许多研究表明雄激素调节各种生长因子的水平。在本研究中，研究了转化生长因子-β (TGF-β) 在介导雄激素调节的 LNCaP 细胞生长停滞中的作用。使用以下浓度的 DHT：0、10(-12)、10(-10) 和 10(-7) M。选择这些浓度是因为它们分别代表零 DHT 对照、低增殖剂量、高增殖剂量和生长停滞剂量。 RT-PCR结果显示LNCaP细胞表达TGF-β1，但不表达-β2和-β3信使RNA。竞争性定量RT-PCR表明，当细胞用10(-7) M DHT处理时，TGF-β1信使RNA的水平增加了约7倍。蛋白质印迹分析结果显示，随着 DHT 浓度的增加，细胞裂解物中潜在的 TGF-β1 蛋白水平显着增加。此外，TGF-β1 酶联免疫吸附测定结果表明，用 DHT 处理 LNCaP 细胞会导致条件培养基中总 TGF-β1 和生物活性 TGF-β1 呈剂量依赖性增加。为了确定 TGF-β1 在调节 LNCaP 增殖中的作用，通过两种不同但互补的方法阻断 TGF-β1 的作用。首先，将TGF-β1中和抗体添加到含有不同浓度DHT的培养基中。其次，以类似的方式将 6-磷酸甘露糖添加到培养物中，该物质已被证明可以抑制潜在 TGF-β1 的激活。结果表明，随着DHT高剂量下观察到的生长抑制被消除，用增加剂量的DHT处理后的特征性钟形生长反应转变为线性剂量反应曲线。这些观察结果综合起来表明，TGF-β1 至少部分介导了 LNCaP 细胞中在高浓度 DHT 下观察到的生长停滞。
LNCaP is an androgen-responsive prostatic cancer cell line that exhibits a bell-shaped growth response to increasing doses of dihydrotestosterone (DHT) in culture. Although the precise mechanism responsible for this growth response to androgen stimulation remains unclear, many studies have suggested that androgen modulates the level of various growth factors. In the present study, the role of transforming growth factor-beta (TGF-beta) in mediating the androgen-regulated growth arrest of LNCaP cells was investigated. The following concentrations of DHT were used: 0, 10(-12), 10(-10), and 10 (-7) M. These concentrations were selected because they represent the zero DHT control, the low-proliferative dose, the high-proliferative dose, and the growth arrest dose, respectively. Results of RT-PCR showed that LNCaP cells express TGF-beta1 but not -beta2 and -beta3 messenger RNA. Competitive quantitative RT-PCR demonstrated that the level of TGF-beta1 messenger RNA increased approximately 7-fold when cells were treated with 10(-7) M DHT. Results of Western blot analysis showed a dramatic increase in the level of latent TGF-beta1 protein in cell lysates with increasing concentrations of DHT. In addition, results of enzyme-linked immunoadsorbent assay for TGF-beta1 indicated that treatment of LNCaP cells with DHT led to a dose-dependent increase in both total and biologically active TGF-beta1 in the conditioned media. To determine the role of TGF-beta1 in regulating LNCaP proliferation, the action of TGF-beta1 was blocked by two different but complementary approaches. First, TGF-beta1 neutralizing antibody was added to the culture medium with varying concentrations of DHT. Second, mannose-6-phosphate, which has been demonstrated to inhibit the activation of latent TGF-beta1, was added in a similar manner to the culture. Results demonstrated that the characteristic bell- shaped growth response following treatment with increasing doses of DHT was converted to a linear dose-response curve as the growth of inhibition seen at the high dose by DHT was abolished. These observations, taken together, indicate that TGF-beta1 mediates at least in part the growth arrest observed at the high concentration of DHT in LNCaP cells.