Rivas C I, Vera J C, Delgado-López F, Heaney M L, Guaiquil V H, Zhang R H, Scher H I, Concha I I, Nualart F, Cordon-Cardo C, Golde D W
Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Blood. 1998 Feb 1;91(3):1037-43.
We studied the expression and function of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor in the human prostate carcinoma cell line LNCaP and looked for its presence in normal and neoplastic human prostatic tissue. The GM-CSF receptor is composed of two subunits, alpha and beta. While the isolated alpha subunit binds GM-CSF at low-affinity, the isolated beta subunit does not bind GM-CSF by itself; but complexes with the alpha subunit to form a high-affinity receptor. Quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) showed expression of mRNAs encoding the alpha and beta subunits of the GM-CSF receptor in LNCaP cells, and the presence of the alpha and beta proteins was confirmed by immunolocalization with anti-alpha and anti-beta antibodies. Receptor binding studies using radiolabeled GM-CSF showed that LNCaP cells have about 150 high-affinity sites with a kd of 40 pmol/L and approximately 750 low-affinity sites with a kd of 2 nmol/L. GM-CSF signaled, in a time- and dose-dependent manner, for protein tyrosine phosphorylation and induced the proliferation of the LNCaP cells. Immunolocalization studies showed low level expression of GM-CSF alpha and beta subunits in normal prostate tissue, with substantial expression in benign prostatic hyperplasia and prominent expression in neoplastic prostate tissue. Maximal expression of both subunits was observed in prostatic carcinomas metastatic to lymph node and bone. Tumor cells that stained positively with anti-alpha subunit antibodies were also reactive with anti-beta subunit antibodies, indicating that they express high-affinity GM-CSF receptors. Our data show that the LNCaP cells express functional GM-CSF receptors and that prostatic carcinomas have prominent GM-CSF receptor expression. These findings imply that both hyperplastic and neoplastic prostatic tissues may be responsive to GM-CSF.
我们研究了粒细胞-巨噬细胞集落刺激因子（GM-CSF）受体在人前列腺癌细胞系LNCaP中的表达及功能，并探寻其在正常和肿瘤性人前列腺组织中的存在情况。GM-CSF受体由α和β两个亚基组成。虽然分离出的α亚基以低亲和力结合GM-CSF，但分离出的β亚基自身并不结合GM-CSF；而是与α亚基形成复合物以形成高亲和力受体。定量逆转录聚合酶链反应（RT-PCR）显示LNCaP细胞中编码GM-CSF受体α和β亚基的mRNA有表达，并且通过用抗α和抗β抗体进行免疫定位证实了α和β蛋白的存在。使用放射性标记的GM-CSF进行的受体结合研究表明，LNCaP细胞有大约150个kd为40 pmol/L的高亲和力位点和约750个kd为2 nmol/L的低亲和力位点。GM-CSF以时间和剂量依赖性方式引发蛋白酪氨酸磷酸化，并诱导LNCaP细胞增殖。免疫定位研究显示GM-CSFα和β亚基在正常前列腺组织中低水平表达，在良性前列腺增生中大量表达，在肿瘤性前列腺组织中显著表达。在转移至淋巴结和骨的前列腺癌中观察到两个亚基的最大表达。用抗α亚基抗体染色呈阳性的肿瘤细胞也与抗β亚基抗体反应，表明它们表达高亲和力GM-CSF受体。我们的数据表明LNCaP细胞表达功能性GM-CSF受体，并且前列腺癌有显著的GM-CSF受体表达。这些发现意味着增生性和肿瘤性前列腺组织可能对GM-CSF有反应。
