Department of Urology, Nihon University School of Medicine, Itabashi-ku, Tokyo 173-8610, Japan.
Int J Oncol. 2013 Nov;43(5):1441-6. doi: 10.3892/ijo.2013.2073. Epub 2013 Aug 21.
We investigated the clinical significance of the expression levels of matrix metalloproteinase 9 (MMP-9) in renal cell carcinoma (RCC). In addition, we validated the efficacy of pyrrole imidazole polyamide (PIP) targeting MMP-9 on inhibiting proliferation and invasion of RCC. We evaluated the expression levels of MMP-9 in 249 RCC specimens by immunostaining and analyzed the association between MMP-9 expression levels and cancer-specific survival. Furthermore, in a human RCC cell line, Caki-2, we tested the effect of a couple of PIPs targeting MMP-9 one recognizing an NF-κB binding site (MMP-9-NF-κB PIP) and another for the AP-1 binding site (MMP-9-AP-1 PIP) in the MMP-9 promoter. The expression levels of MMP-9, proliferative activity and invasive capability were tested by quantitative PCR, WST8 assay and Matrigel invasion assay, respectively. By immunostaining of the clinical specimens, strong MMP-9 staining was proven to be a significant predictor of poor prognosis for cancer-specific survival (P<0.01). In Caki-2 cells, MMP-9-NF-κB PIP significantly reduced the expression levels of MMP-9 mRNA and inhibited cell invasion, but did not affect the cell proliferation activity. On the other hand, no effect was found in MMP-9-AP-1 PIP on MMP-9 mRNA expression, cell proliferation and invasion. We confirmed the inhibitory effects of MMP-9-NF-κB PIP on the expression of MMP-9 and subsequent invasion of Caki-2 cells. Since it was clearly shown that high MMP-9 expression levels were associated with poor prognosis of RCC, MMP-9 is a potential candidate target for RCC treatment. Transcription therapy using a minor groove binder, such as NF-κB PIP, may be a potential therapeutic agent for RCC, although further investigation is required.
我们研究了基质金属蛋白酶 9（MMP-9）在肾细胞癌（RCC）中的表达水平的临床意义。此外，我们验证了靶向 MMP-9 的吡咯并咪唑聚酰胺（PIP）抑制 RCC 增殖和侵袭的疗效。我们通过免疫染色评估了 249 例 RCC 标本中 MMP-9 的表达水平，并分析了 MMP-9 表达水平与癌症特异性生存之间的关系。此外，在人 RCC 细胞系 Caki-2 中，我们测试了靶向 MMP-9 的一对 PIP 的作用，一个识别 NF-κB 结合位点（MMP-9-NF-κB PIP），另一个识别 AP-1 结合位点（MMP-9-AP-1 PIP）在 MMP-9 启动子中。通过定量 PCR、WST8 测定和 Matrigel 侵袭测定分别检测 MMP-9 的表达水平、增殖活性和侵袭能力。通过对临床标本的免疫染色，强烈的 MMP-9 染色被证明是癌症特异性生存不良预后的显著预测因子（P<0.01）。在 Caki-2 细胞中，MMP-9-NF-κB PIP 显著降低 MMP-9 mRNA 的表达水平并抑制细胞侵袭，但不影响细胞增殖活性。另一方面，MMP-9-AP-1 PIP 对 MMP-9 mRNA 表达、细胞增殖和侵袭均无影响。我们证实了 MMP-9-NF-κB PIP 对 Caki-2 细胞 MMP-9 表达和随后侵袭的抑制作用。由于高 MMP-9 表达水平与 RCC 的不良预后相关，因此 MMP-9 是 RCC 治疗的潜在候选靶点。使用小沟结合物（如 NF-κB PIP）进行转录治疗可能是 RCC 的一种潜在治疗剂，尽管需要进一步研究。
