Abstract：
ADAM10 acts upstream of Notch signaling and plays oncogenic roles in various cancers. Tetraspanin family proteins regulate ADAM10 trafficking and activity. Here, we aimed to investigate whether and how tetraspanin-29 modulates ADAM10 in colorectal cancer (CRC). We found that ADAM10 expression was upregulated in CRC tissues and this was cross-validated in the TCGA COAD data set. The ADAM10 protein level and its α-secretase activity were enhanced in CRC cell lines compared with control cell lines. Co-immunoprecipitation showed ADAM10 interacted with tetraspanin-29 in the LoVo cell line. Tetraspanin-29 knockdown reduced the cell surface trafficking and α-secretase activity of ADAM10. In addition, tetraspanin-29 knockdown inhibited Notch activity in a luciferase reporter assay and reduced the levels of cleaved Notch1 and Notch target genes such as HES2, c-MYC, and cyclin D3. Consistently, tetraspanin-29 overexpression increased cleaved Notch1 and this effect was blocked by ADAM10 inhibitors. The TCGA COAD data set confirmed the positive correlations of tetraspanin-29 with HES2, c-MYC, and cyclin D3. Thus, the tetraspanin-29/ADAM10/Notch pathway plays an important role in CRC.
摘要：
ADAM10在Notch信号传导的上游起作用，并在各种癌症中发挥致癌作用。Tetraspanin家族蛋白调节ADAM10的运输和活性。这里,我们旨在研究tetraspanin-29是否以及如何在结直肠癌(CRC)中调节ADAM10.我们发现ADAM10表达在CRC组织中上调，这在TCGACOAD数据集中得到了交叉验证。与对照细胞系相比，CRC细胞系中的ADAM10蛋白水平及其α-分泌酶活性得到增强。免疫共沉淀显示，在LoVo细胞系中，ADAM10与tetraspanin-29相互作用。Tetraspanin-29敲低降低了ADAM10的细胞表面运输和α-分泌酶活性。此外,tetraspanin-29敲低在荧光素酶报告基因测定中抑制Notch活性，并降低切割的Notch1和Notch靶基因的水平，例如HES2，c-MYC，和细胞周期蛋白D3。始终如一，tetraspanin-29过表达增加了切割的Notch1，并且这种作用被ADAM10抑制剂阻断。TCGACOAD数据集证实了tetraspanin-29与HES2，c-MYC，和细胞周期蛋白D3。因此，tetraspanin-29/ADAM10/Notch通路在CRC中发挥重要作用。
