Birch M A, Carron J A, Scott M, Fraser W D, Gallagher J A
Department of Human Anatomy and Cell Biology, University of Liverpool, UK.
Br J Cancer. 1995 Jul;72(1):90-5. doi: 10.1038/bjc.1995.282.
Previous reports have shown the production of parathyroid hormone-related protein (PTHrP) by breast cancer cells in vivo and in vitro. We have investigated the expression of the PTH/PTHrP receptor by the human breast cancer cell lines MCF-7, ZR-75-1, T-47-D, SK-BR-3, Hs578T and MDA-MB231. Using reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analysis, we detected transcripts for the receptor in MCF-7, SK-BR-3 and MDA-MB231 cells. There was no evidence of receptor mRNA in ZR-75-1 and Hs578T cells. Furthermore, Northern blot analysis of mRNA from MCF-7 cells showed two transcripts of 1.5 and 2.4 kb which coded for the PTH/PTHrP receptor. Expression of PTH/PTHrP receptor mRNA by the breast cancer cell lines was also correlated with the detection of PTHrP transcripts. RT-PCR demonstrated PTHrP mRNA in MCF-7, ZR-75-1, T-47-D and Hs578T cells, but not in SK-BR-3 and MDA-MB231 cells. The detection of receptor transcripts was complemented by [3H]thymidine and bromodeoxyuridine incorporation studies, in which mitogenic responses to PTH and PTHrP were observed in MCF-7 cells but not in Hs578T cells. In response to both PTH(1-34) and PTHrP(1-34), quiescent MCF-7 cells proliferated in a similar dose-dependent manner (1.6-100 ng ml-1). No mitogenic effects of these peptides were observed with Hs578T cells. In addition, levels of intracellular cAMP were measured in MCF-7 and Hs578T cells in response to PTHrP(1-34). In MCF-7 cells there was a significant rise in cAMP with 100 ng ml-1 PTHrP(1-34). The expression of PTH/PTHrP receptor by breast cancer cells suggests that PTHrP may be a paracrine/autocrine regulator of breast carcinoma.
以往的报道显示，乳腺癌细胞在体内和体外均可产生甲状旁腺激素相关蛋白（PTHrP）。我们研究了人乳腺癌细胞系MCF-7、ZR-75-1、T-47-D、SK-BR-3、Hs578T和MDA-MB231中PTH/PTHrP受体的表达情况。利用逆转录-聚合酶链反应（RT-PCR）和Southern印迹分析，我们在MCF-7、SK-BR-3和MDA-MB231细胞中检测到了该受体的转录本。在ZR-75-1和Hs578T细胞中未发现受体mRNA的证据。此外，对MCF-7细胞mRNA的Northern印迹分析显示有1.5 kb和2.4 kb的两种转录本，它们编码PTH/PTHrP受体。乳腺癌细胞系中PTH/PTHrP受体mRNA的表达也与PTHrP转录本的检测相关。RT-PCR显示MCF-7、ZR-75-1、T-47-D和Hs578T细胞中有PTHrP mRNA，但SK-BR-3和MDA-MB231细胞中没有。[3H]胸腺嘧啶核苷和溴脱氧尿苷掺入研究补充了受体转录本的检测，其中在MCF-7细胞中观察到了对PTH和PTHrP的促有丝分裂反应，而在Hs578T细胞中未观察到。对PTH(1-34)和PTHrP(1-34)的反应中，静止的MCF-7细胞以类似的剂量依赖性方式增殖（1.6 - 100 ng/ml）。Hs578T细胞未观察到这些肽的促有丝分裂作用。此外，测定了MCF-7和Hs578T细胞对PTHrP(1-34)反应时细胞内cAMP的水平。在MCF-7细胞中，100 ng/ml PTHrP(1-34)可使cAMP显著升高。乳腺癌细胞中PTH/PTHrP受体的表达表明，PTHrP可能是乳腺癌的一种旁分泌/自分泌调节因子。
