Biomedical Research Center of the Slovak Academy of Sciences, Institute of Virology, Department of Tumor Biology, 84505 Bratislava, Slovakia.
Oncol Rep. 2023 Feb;49(2). doi: 10.3892/or.2022.8464. Epub 2022 Dec 16.
Carbonic anhydrase IX (CA IX) is a transmembrane enzyme participating in adaptive responses of tumors to hypoxia and acidosis. CA IX regulates pH, facilitates metabolic reprogramming, and supports migration, invasion and metastasis of cancer cells. Extracellular domain (ECD) of CA IX can be shed to medium and body fluids by a disintegrin and metalloproteinase (ADAM) 17. Here we show for the first time that CA IX ECD shedding can be also executed by ADAM10, a close relative of ADAM17, via an overlapping cleavage site in the stalk region of CA IX connecting its exofacial catalytic site with the transmembrane region. This finding is supported by biochemical evidence using recombinant human ADAM10 protein, colocalization of ADAM10 with CA IX, ectopic expression of a dominant‑negative mutant of ADAM10 and RNA interference‑mediated suppression of ADAM10. Induction of the CA IX ECD cleavage with ADAM17 and/or ADAM10 activators revealed their additive effect. Similarly, additive effect was observed with an ADAM17‑inhibiting antibody and an ADAM10‑preferential inhibitor GI254023X. These data indicated that ADAM10 is a CA IX sheddase acting on CA IX non‑redundantly to ADAM17.
碳酸酐酶 9（CA9）是一种参与肿瘤对缺氧和酸中毒的适应性反应的跨膜酶。CA9 调节 pH 值，促进代谢重编程，并支持癌细胞的迁移、侵袭和转移。CA9 的细胞外结构域（ECD）可通过解整合素金属蛋白酶 17（ADAM17）脱落到细胞外基质和体液中。我们首次表明，CA9 的 ECD 脱落也可以通过 ADAM10 执行，ADAM10 是 ADAM17 的密切相关蛋白，通过 CA9 连接其细胞外催化位点和跨膜区域的茎区的重叠裂解位点。这一发现得到了使用重组人 ADAM10 蛋白的生化证据、ADAM10 与 CA9 的共定位、ADAM10 显性负突变体的异位表达以及 ADAM10 的 RNA 干扰介导的抑制的支持。用 ADAM17 和/或 ADAM10 激活剂诱导 CA9 ECD 切割显示出它们的相加效应。同样，用 ADAM17 抑制抗体和 ADAM10 优先抑制剂 GI254023X 观察到了相加效应。这些数据表明，ADAM10 是一种 CA9 脱落酶，对 CA9 的作用与 ADAM17 不同。
