Hu Weidong, Zhen Xinming, Xiong Bin, Wang Bicheng, Zhang Weibing, Zhou Wenhui
Department of Oncology, Zhongnan Hospital of Wuhan University, Wuhan 430071, China.
Cancer Sci. 2008 Jul;99(7):1362-9. doi: 10.1111/j.1349-7006.2008.00833.x. Epub 2008 Apr 29.
In spite of the clinical importance of prostate cancer (PCa) bone metastasis, the precise mechanisms for the directed migration of malignant cells remain unclear. In the present study, the expression of CXCR6 in human PCa and benign prostatic hyperplasia samples, and the expression of CXCL16 in human osseous tissues were determined by immunohistochemistry. It was found that the level of CXCR6 protein expression was elevated in human malignant prostate tumors, and CXCL16 was expressed positively by human osteocytes in vivo. The in vitro experiments further confirmed that the PCa cell lines PC3 and LNCap expressed CXCR6 at both the mRNA and protein levels, and exogenous CXCL16 has the potential to stimulate the invasion of PC3 and LNCap. To further elucidate the role of the CXCL16-CXCR6 axis in PCa progression, we compared the expression of CXCR6 and CXCR4 in human PCa tissues and the effects of CXCL16 and CXCL12 on the in vitro invasion of PC3 and LNCap cells. It was shown that CXCR6 and CXCR4 proteins were coexpressed and elevated in human PCa samples, and CXCL16 and CXCL12 promoted the invasion of PC3 and LNCap via their respective receptors. Furthermore, in contrast to CXCL12, which enhanced the activity of matrix metalloproteinase (MMP) 9 and MMP2 in PC3 and LNCap, CXCL16 ligation resulted in stronger MMP9 and MMP2 activity in LNCap but not in PC3. Our results suggest that besides CXCL12/CXCR4, CXCL16/CXCR6 might be another important factor involved in PCa bone metastasis.
尽管前列腺癌(PCa)骨转移具有临床重要性,但恶性细胞定向迁移的精确机制仍不清楚。在本研究中,通过免疫组织化学测定了人PCa和良性前列腺增生样本中CXCR6的表达,以及人骨组织中CXCL16的表达。结果发现,人恶性前列腺肿瘤中CXCR6蛋白表达水平升高,且CXCL16在体内由人骨细胞呈阳性表达。体外实验进一步证实,PCa细胞系PC3和LNCap在mRNA和蛋白水平均表达CXCR6,外源性CXCL16具有刺激PC3和LNCap侵袭的潜力。为了进一步阐明CXCL16 - CXCR6轴在PCa进展中的作用,我们比较了人PCa组织中CXCR6和CXCR4的表达,以及CXCL16和CXCL12对PC3和LNCap细胞体外侵袭的影响。结果表明,CXCR6和CXCR4蛋白在人PCa样本中共表达且升高,CXCL16和CXCL12通过各自的受体促进PC3和LNCap的侵袭。此外,与增强PC3和LNCap中基质金属蛋白酶(MMP)9和MMP2活性的CXCL12不同,CXCL16连接导致LNCap中MMP9和MMP2活性增强,但在PC3中未增强。我们的结果表明,除了CXCL12/CXCR4外,CXCL16/CXCR6可能是参与PCa骨转移的另一个重要因素。