Vaday Gayle G, Hua Shao-Bing, Peehl Donna M, Pauling Michelle H, Lin Yu-Huei, Zhu Li, Lawrence Diana M, Foda Hussein D, Zucker Stanley
Department of Research, Veterans Affairs Medical Center, Northport, New York 11768, USA.
Clin Cancer Res. 2004 Aug 15;10(16):5630-9. doi: 10.1158/1078-0432.CCR-03-0633.
Metastasis is a major cause of morbidity in prostate cancer (PCa). Several studies have shown that the chemokine receptor CXCR4 and its ligand, CXCL12 (stromal cell-derived factor-1), regulate tumor cell metastasis to specific organs. Recently, it was demonstrated that CXCL12 enhances PCa cell adhesion, migration, and invasion, implicating CXCR4 in PCa metastasis. In this study, we examined the inhibitory effects of anti-CXCR4 antibodies on CXCL12-mediated PCa cell activities.
We developed fully human single chain Fv antibodies (scFv), Ab124 and Ab125, against CXCR4 using the yeast two-hybrid system. We performed immunofluorescent staining, flow cytometry, and ELISA-binding assays to measure scFv binding to PCa cells. We also examined the effects of scFv on CXCL12-mediated calcium mobilization, cell migration, and invasion.
Our results confirmed that PCa cell lines express cell-surface CXCR4. Real-time quantitative reverse transcription-PCR and immunohistochemical staining also verified that CXCR4 is expressed in primary cultures of prostate epithelial cells from adenocarcinomas and in human prostate tissues. Ab124 and Ab125 demonstrated specific binding to PCa cell lines by flow cytometry and in binding assays. Preincubation with scFv resulted in significant reduction of CXCL12-induced calcium mobilization in PC-3 and LNCaP cells. Ab124 and Ab125 also inhibited PCa cell migration toward CXCL12, as well as invasion through extracellular matrix gels.
Ab124 and Ab125 inhibit CXCL12-mediated cellular activities by binding the receptor CXCR4. Recombinant scFv are an efficient mode of targeting tumor antigens. Considering the high incidence of PCa, the development of fully human scFv may be a useful therapeutic approach in the prevention and treatment of PCa metastasis.
转移是前列腺癌（PCa）发病的主要原因。多项研究表明，趋化因子受体CXCR4及其配体CXCL12（基质细胞衍生因子-1）调节肿瘤细胞向特定器官的转移。最近，有研究表明CXCL12可增强PCa细胞的黏附、迁移和侵袭能力，这表明CXCR4参与了PCa的转移过程。在本研究中，我们检测了抗CXCR4抗体对CXCL12介导的PCa细胞活性的抑制作用。
我们利用酵母双杂交系统开发了针对CXCR4的完全人源单链Fv抗体（scFv），即Ab124和Ab125。我们进行了免疫荧光染色、流式细胞术和ELISA结合试验，以检测scFv与PCa细胞的结合情况。我们还研究了scFv对CXCL12介导的钙动员、细胞迁移和侵袭的影响。
我们的结果证实PCa细胞系表达细胞表面CXCR4。实时定量逆转录PCR和免疫组化染色也证实CXCR4在腺癌前列腺上皮细胞的原代培养物和人前列腺组织中表达。通过流式细胞术和结合试验，Ab124和Ab125显示出与PCa细胞系的特异性结合。与scFv预孵育可显著降低PC-3和LNCaP细胞中CXCL12诱导的钙动员。Ab124和Ab125还抑制了PCa细胞向CXCL12的迁移以及穿过细胞外基质凝胶的侵袭。
Ab124和Ab125通过结合受体CXCR4抑制CXCL12介导的细胞活性。重组scFv是靶向肿瘤抗原的有效方式。鉴于PCa的高发病率，开发完全人源scFv可能是预防和治疗PCa转移的一种有用的治疗方法。
