Asakuma Junichi, Sumitomo Makoto, Asano Takako, Asano Tomohiko, Hayakawa Masamichi
Department of Urology, National Defense Medical College, Tokorozawa, Saitama, Japan.
J Urol. 2004 Feb;171(2 Pt 1):897-902. doi: 10.1097/01.ju.0000095445.79222.ff.
ZD1839 or Iressa (AstraZeneca, Macclesfield, United Kingdom) is an orally active, selective epidermal growth factor receptor tyrosine kinase inhibitor. We evaluated the antitumor activity of ZD1839 in human renal cell carcinomas (RCC).
Six established human RCC lines and surgical specimens from 10 patients with RCC were used. Protein expression was detected by Western blotting and/or immunohistochemistry. The concentrations of vascular endothelial growth factor and interleukin-8 in the supernatants were measured by enzyme-linked immunosorbent assay. Cell cycle progression and the apoptotic ratio were evaluated by flow cytometry. In vitro angiogenesis was measured using human umbilical vascular endothelial cells by capillary-like network formation analysis. In vivo SKRC-49 cells injected subcutaneously into athymic nude mice were treated with various doses of ZD1839 orally. The effect of ZD1839 on tumor xenografts angiogenesis was evaluated by immunohistochemistry using CD34 Ab.
Epidermal growth factor receptor was activated in all RCC lines and over expressed in 7 of 10 RCC specimens (70%) compared with adjacent normal renal tissues. Treatment of SKRC-49 cells with ZD1839 (0.1 to 10 microM) for 48 hours resulted in the accumulation of cells in the G1 phase and a 30% to 50% decrease in cellular proliferation compared with untreated controls (p <0.01). The tumor xenograft study confirmed that ZD1839 (50 to 100 mg/kg daily) significantly inhibited SKRC-49 tumor growth compared with controls within 3 weeks after treatment (p <0.01). Vascular endothelial growth factor and interleukin-8 production was significantly decreased in ZD1839 treated SKRC-49 cells compared with untreated controls (p <0.01). Treatment of human umbilical vascular endothelial cells with SKRC-49 supernatants treated with ZD1839 for 11 days resulted in an approximate 80% decrease in tubule formation compared with untreated controls (p <0.01). Immunohistochemical assays showed that ZD1839 treatment resulted in a significant decrease in CD34 positive neovessels compared with controls in SKRC-49 xenografts.
These results suggest that the antitumor activity of ZD1839 appears to derive not only from direct inhibition of cell proliferation, but also from the inhibition of tumor angiogenesis in RCC.
ZD1839（易瑞沙，阿斯利康公司，英国麦克尔斯菲尔德）是一种口服活性、选择性表皮生长因子受体酪氨酸激酶抑制剂。我们评估了ZD1839对人肾细胞癌（RCC）的抗肿瘤活性。
使用6种已建立的人RCC细胞系以及10例RCC患者的手术标本。通过蛋白质印迹法和/或免疫组织化学检测蛋白质表达。采用酶联免疫吸附测定法测量上清液中血管内皮生长因子和白细胞介素8的浓度。通过流式细胞术评估细胞周期进程和凋亡率。使用人脐静脉血管内皮细胞通过类毛细血管网络形成分析来测量体外血管生成。将SKRC - 49细胞皮下注射到无胸腺裸鼠体内，然后口服给予不同剂量的ZD1839进行治疗。使用CD34抗体通过免疫组织化学评估ZD1839对肿瘤异种移植物血管生成的影响。
在所有RCC细胞系中表皮生长因子受体均被激活，与相邻正常肾组织相比，10例RCC标本中有7例（70%）过表达。用ZD1839（0.1至10 microM）处理SKRC - 49细胞48小时，导致细胞在G1期积累，与未处理的对照相比，细胞增殖降低30%至50%（p<0.01）。肿瘤异种移植研究证实，与对照相比，ZD1839（每日50至100 mg/kg）在治疗后3周内显著抑制SKRC - 49肿瘤生长（p<0.01）。与未处理的对照相比，用ZD1839处理的SKRC - 49细胞中血管内皮生长因子和白细胞介素8的产生显著降低（p<0.01）。用ZD1839处理11天的SKRC - 49上清液处理人脐静脉血管内皮细胞，与未处理的对照相比，小管形成减少约80%（p<0.01）。免疫组织化学分析表明，与SKRC - 49异种移植物中的对照相比，ZD1839治疗导致CD34阳性新生血管显著减少。
这些结果表明，ZD1839的抗肿瘤活性似乎不仅源于对细胞增殖的直接抑制，还源于对RCC肿瘤血管生成的抑制。
