Takeuchi Susumu, Seike Masahiro, Noro Rintaro, Soeno Chie, Sugano Teppei, Zou Fenfei, Uesaka Haruka, Nishijima Nobuhiko, Matsumoto Masaru, Minegishi Yuji, Kubota Kaoru, Gemma Akihiko
Department of Pulmonary Medicine and Oncology, Graduate School of Medicine, Nippon Medical School, Tokyo 113-8603, Japan.
MediBIC Group, Tokyo 102-8578, Japan.
Int J Oncol. 2014 Jun;44(6):1886-94. doi: 10.3892/ijo.2014.2370. Epub 2014 Apr 7.
Pemetrexed (PEM) is currently recommended as one of the standard anticancer drugs for malignant pleural mesothelioma (MPM). However, the mechanism of the sensitivity of MPM to PEM remains unclear. We analyzed the antitumor effects of PEM in six MPM cell lines by MTS assay. To identify genes associated with drug sensitivity, we conducted gene expression profiling on the same set of cell lines using GeneChips and pathway analysis. Three cell lines were sensitive to PEM. A total fo 18 transcripts and 14 genes identified by GeneChips were significantly correlated with sensitivity to PEM. Pathway analysis revealed that osteopontin (SPP1/OPN) was an important target in PEM sensitivity. Overexpression of SPP1/OPN was observed in the sensitive cells by quantitative PCR and western blot analysis. Introduction of SPP1/OPN by lentiviral vector significantly enhanced the invasion activities of MPM cells. PEM treatment with SPP1/OPN knockdown inhibited the PEM-induced cell growth-inhibitory effect in PEM-sensitive cells. Expression of SPP1/OPN and AKT phosphorylation significantly decreased after PEM treatment of the PEM-sensitive cells. High immunohistochemical expression of SPP1/OPN was observed in two of three MPM patients who had a partial response to PEM-based chemotherapy. PEM has antitumor effects in MPM cells dependent on SPP1/OPN overexpression resulting in AKT activation. Our results suggest that SPP1 may be used as a single predictive biomarker of the effectiveness of PEM treatment in MPM.
培美曲塞（PEM）目前被推荐作为恶性胸膜间皮瘤（MPM）的标准抗癌药物之一。然而，MPM对PEM敏感的机制仍不清楚。我们通过MTS试验分析了PEM对六种MPM细胞系的抗肿瘤作用。为了鉴定与药物敏感性相关的基因，我们使用基因芯片对同一组细胞系进行了基因表达谱分析和通路分析。三个细胞系对PEM敏感。基因芯片鉴定出的总共18个转录本和14个基因与对PEM的敏感性显著相关。通路分析显示骨桥蛋白（SPP1/OPN）是PEM敏感性的一个重要靶点。通过定量PCR和蛋白质印迹分析在敏感细胞中观察到SPP1/OPN的过表达。通过慢病毒载体导入SPP1/OPN显著增强了MPM细胞的侵袭活性。在PEM敏感细胞中，用SPP1/OPN敲低进行PEM处理可抑制PEM诱导的细胞生长抑制作用。对PEM敏感细胞进行PEM处理后，SPP1/OPN的表达和AKT磷酸化显著降低。在三名对基于PEM的化疗有部分反应的MPM患者中，有两名观察到SPP1/OPN的高免疫组化表达。PEM在MPM细胞中具有抗肿瘤作用，依赖于SPP1/OPN的过表达导致AKT激活。我们的结果表明，SPP1可能用作MPM中PEM治疗有效性的单一预测生物标志物。
