Acidic extracellular pH promotes experimental metastasis of human melanoma cells in athymic nude mice
Acidic extracellular pH promotes experimental metastasis of human melanoma cells in athymic nude mice
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DOI：
10.1158/0008-5472.can-06-0983
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发表时间：
2006-07-01
期刊：
影响因子：
11.2
通讯作者：
Galappathi, Kanthi
中科院分区：
文献类型：
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作者：
Rofstad, Einar K.;Mathiesen, Berit;Galappathi, Kanthi
许多肿瘤中的细胞外 pH (pH(e)) 低于相应的正常组织。这。本工作研究了酸性 pH(e) 在转移性疾病发展中的重要性。人黑色素瘤细胞（A-07、D-12 和 T-22）在 pH(e) 6.8 或 7.4（对照）下体外培养，然后接种到 BALB/c nu/nu 小鼠的尾静脉中形成实验性肺转移。使用基质胶侵袭室在体外研究细胞侵袭性，并使用皮内测定在体内研究血管生成。通过 ELISA 和免疫捕获测定法测量蛋白质分泌。在酸性 pH(e) 下培养的细胞表现出蛋白酶和促血管生成因子分泌增加、侵袭和血管生成潜力增强以及发生实验性转移的潜力增强。使用通用基质金属蛋白酶 (MMP) 抑制剂 GM6001、通用半胱氨酸蛋白酶抑制剂 E-64 或针对血管内皮生长因子-A (VEGF-A) 或 interleakin-8 (IL-8) 的封闭抗体治疗可抑制酸度诱导的转移。我们的研究表明，酸性 pH(e) 通过一种常见机制促进 A-07、D-12 和 T-22 人黑色素瘤细胞的实验性肺转移，该机制涉及酸性诱导的蛋白水解酶 MMP-2、MMP-9、组织蛋白酶 B 和组织蛋白酶 L 的上调以及酸性诱导的促血管生成因子 VEGF-A 和 IL-8 的上调。这一观察结果的一个结果是，应避免涉及故意肿瘤酸化以提高化疗、光动力疗法和热疗疗效的治疗策略。此外，原发肿瘤的 pH(e) 可能是黑色素瘤患者重要的预后参数，这一可能性值得临床研究。
Extracellular pH (pH(e)) is lower in many tumors than in the corresponding normal tissue. The. significance of acidic pH(e) in the development of metastatic disease was investigated in the present work. Human melanoma cells (A-07, D-12, and T-22) were cultured in vitro at pH(e) 6.8 or 7.4 (control) before being inoculated into the tail vein of BALB/c nu/nu mice for formation of experimental pulmonary metastases. Cell invasiveness was studied in vitro by using Matrigel invasion chambers and angiogenesis was studied in vivo by using an intradermal assay. Protein secretion was measured by ELISA and immunocapture assays. Cells cultured at acidic pH(e) showed increased secretion of proteinases and proangiogenic factors, enhanced invasive and angiogenic potential, and enhanced potential to develop experimental metastases. Acidity-induced metastasis was inhibited by treatment with the general matrix metalloproteinase (MMP) inhibitor GM6001, the general cysteine proteinase inhibitor E-64, or blocking antibody against vascular endothelial growth factor-A (VEGF-A) or interleakin-8 (IL-8). Our study indicates that acidic pH(e) promotes experimental pulmonary metastasis in A-07, D-12, and T-22 human melanoma cells by a common mechanism involving acidity-induced up-regulation of the proteolytic enzymes MMP-2, MMP-9, cathepsin B, and cathepsin L and acidity-induced up-regulation of the proangiogenic factors VEGF-A and IL-8. One consequence of this observation is that treatment strategies involving deliberate tumor acidification to improve the efficacy of chemotherapy, photodynamic therapy, and hyperthermia should be avoided. Moreover, the possibility that the pH(e) of the primary tumor may be an important prognostic parameter for melanoma patients merits clinical investigation.