SYNTHESIS AND SECRETION OF PLATELET-DERIVED GROWTH-FACTOR BY HUMAN-BREAST CANCER CELL-LINES
SYNTHESIS AND SECRETION OF PLATELET-DERIVED GROWTH-FACTOR BY HUMAN-BREAST CANCER CELL-LINES
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DOI：
10.1073/pnas.84.16.5763
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发表时间：
1987-08-01
影响因子：
11.1
通讯作者：
LIPPMAN, ME
中科院分区：
文献类型：
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作者：
BRONZERT, DA;PANTAZIS, P;LIPPMAN, ME
我们报告说，人类乳腺癌细胞分泌一种在生物学和免疫学上与血小板衍生生长因子（PDGF）相似的生长因子。由雌激素非依赖性 MDA-MB-231 或雌激素依赖性 MCF-7 细胞条件化的无血清培养基含有促有丝分裂或“活性”活性，能够在贫血小板血浆存在的情况下诱导 [3H] 胸苷掺入静止的 Swiss 3T3 细胞中。此外，条件培养基含有与 125I 标记的 PDGF 竞争与正常人成纤维细胞上的 PDGF 受体结合的活性。激素应答细胞系MCF-7分泌PDGF样活性受到17β-雌二醇的刺激。与真正的 PDGF 一样，乳腺癌细胞产生的 PDGF 样活性在酸和热处理（95°C）后保持稳定，并被还原剂抑制。有丝分裂活性与.apprxeq的材料共迁移。 NaDodSO4/聚丙烯酰胺凝胶上为 30 kDa。使用 PDGF 抗血清对代谢标记的细胞裂解物和条件培养基中的蛋白质进行免疫沉淀，然后在非还原性 NaDodSO4/聚丙烯酰胺凝胶上进行分析，鉴定出 30 和 34 kDa 的蛋白质。还原后，30-和 34-kDa 带转化为 15-和 16-kDa 带，表明免疫沉淀蛋白由两个与 PDGF 类似的二硫键连接的多肽组成。使用 PDGF A 链和 PDGF/SIS B 链的 cDNA 探针进行杂交研究，鉴定出 MCF-7 和 MDA-MB-231 细胞中两条 PDGF 链的转录本。上面总结的数据为乳腺癌细胞合成和激素调节分泌PDGF样丝裂原提供了确凿的证据。乳腺癌细胞系产生的PDGF样生长因子对于介导肿瘤生长的旁分泌刺激可能很重要。
We report that human breast cancer cells secrete a growth factor that is biologically and immunologically similar to platelet-derived growth factor (PDGF). Serum-free medium conditioned by estrogen-independent MDA-MB-231 or estrogen-dependent MCF-7 cells contains a mitogenic or "competence" activity that is capable of inducing incorporation of [3H]thymidine into quiescent Swiss 3T3 cells in the presence of platelet-poor plasma. In addition, the conditioned medium contains an activity that competes with 125I-labeled PDGF for binding to PDGF receptors on normal human fibroblasts. The secretion of PDGF-like activity by the hormone-responsive cell line MCF-7 is stimulated by 17.beta.-estradiol. Like authentic PDGF, the PDGF-like activity produced by breast cancer cells is stable after acid and heat treatment (95.degree. C) and inhibited by reducing agents. The mitogenic activity comigrates with a material of .apprxeq. 30 kDa on NaDodSO4/polyacrylamide gels. Immunoprecipitation with PDGF antiserum of proteins from metabolically labeled cell lysates and conditioned medium followed by analysis on nonreducing NaDodSO4/polyacrylamide gels identified proteins of 30 and 34 kDa. Upon reduction, the 30- and 34-kDa bands were converted to 15- and 16-kDa bands suggesting that the immunoprecipitated proteins were made up of two disulfide-linked polypeptides similar to PDGF. Hybridization studies with cDNA probes for the A chain of PDGF and the B chain of PDGF/SIS identified transcripts for both PDGF chains in the MCF-7 and MDA-MB-231 cells. The data summarized above provide conclusive evidence for the synthesis and hormonally regulated secretion of a PDGF-like mitogen by breast carcinoma cells. Production of a PDGF-like growth factor by breast cancer cell lines may be important in mediating paracrine stimulation of tumor growth.