Department of Surgery, Division of Cardiothoracic Surgery, University of Colorado at Denver and Health Sciences Center, Aurora, Colorado 80045, USA.
Ann Thorac Surg. 2011 May;91(5):1539-45. doi: 10.1016/j.athoracsur.2011.01.017. Epub 2011 Mar 10.
Esophageal adenocarcinoma is an aggressive malignancy, with most patients succumbing to metastatic disease. The presence of intercellular adhesion molecule-1 (ICAM-1) in these cancer cells contributes to their metastatic potential. The ICAM-1 production in other cell types is stimulated by the actions of phospholipase enzymes. We hypothesize that inhibition of the enzyme secretory phospholipase A2 (sPLA2), which contributes to the growth potential of normal esophageal mucosa and esophageal cancer cells, may attenuate ICAM-1 production and nuclear factor-kappa beta activation in human esophageal adenocarcinoma cells.
The FLO-1 verified human esophageal adenocarcinoma cells were treated with 5-(4-benzyloxyphenyl)-4S-(7-phenylheptanoylamino) pentanoic acid, a specific inhibitor of group IIa sPLA2 (5 μM, 10 μM, and 15 μM doses), followed by tumor necrosis factor-alpha stimulation (20 ng/mL). Cells and medium were collected and analyzed by immunoblotting, flow cytometry, and enzyme-linked immunosorbent assay. Statistical analysis was performed using analysis of variance with the Fisher's least significant difference post-hoc test.
Treatment with sPLA2 inhibitor attenuated total cellular ICAM-1 expression in a dose-dependent manner (p<0.005). Cell-surface and secreted ICAM-1 expression decreased significantly with sPLA2 inhibitor treatment (p<0.001 and p<0.05, respectively). sPLA2 inhibition attenuated nuclear factor-kappa beta activation dose-dependently (p<0.05).
Esophageal adenocarcinoma has significant metastatic potential, and inhibiting its metastasis would significantly advance the treatment of this disease. We demonstrate here that treatment of human esophageal adenocarcinoma cells with sPLA2 inhibitor attenuates the expression of ICAM-1, a marker of metastatic potential, and nuclear factor-kappa beta activation, suggesting a common pathway between the two. These findings identify inhibition of sPLA2 as a potential therapeutic target for esophageal adenocarcinoma.
食管腺癌是一种侵袭性恶性肿瘤，大多数患者死于转移性疾病。这些癌细胞中细胞间黏附分子-1（ICAM-1）的存在促进了其转移潜能。其他细胞类型中 ICAM-1 的产生受到磷脂酶酶作用的刺激。我们假设抑制分泌型磷脂酶 A2（sPLA2）的活性，该酶有助于正常食管黏膜和食管癌细胞的生长潜能，可能会减弱人食管腺癌细胞中 ICAM-1 的产生和核因子-κB 的激活。
使用特定的 IIa 组 sPLA2 抑制剂 5-(4-苄氧基苯基）-4S-(7-苯庚酰氨基）戊酸（5 μM、10 μM 和 15 μM 剂量）处理 FLO-1 验证的人食管腺癌细胞，然后用肿瘤坏死因子-α刺激（20ng/mL）。收集细胞和培养基，通过免疫印迹、流式细胞术和酶联免疫吸附试验进行分析。使用方差分析和 Fisher 最小显著差异事后检验进行统计分析。
sPLA2 抑制剂处理以剂量依赖性方式减弱总细胞 ICAM-1 的表达（p<0.005）。细胞表面和分泌的 ICAM-1 表达随着 sPLA2 抑制剂的处理而显著下降（分别为 p<0.001 和 p<0.05）。sPLA2 抑制以剂量依赖性方式减弱核因子-κB 的激活（p<0.05）。
食管腺癌具有显著的转移潜能，抑制其转移将显著推进该疾病的治疗。我们在此证明，用 sPLA2 抑制剂处理人食管腺癌细胞可减弱 ICAM-1 的表达，ICAM-1 是转移潜能的标志物，以及核因子-κB 的激活，表明两者之间存在共同途径。这些发现确定了抑制 sPLA2 作为食管腺癌的潜在治疗靶点。
