Background

B7 homolog 3 (B7-H3), a member of the immunoregulatory ligand B7 family, is pivotal in T-cell-mediated immune response. It is widely expressed in diverse human tumors and its high expression indicates the poor prognosis of the patients. Nonetheless, B7-H3’s role in colorectal cancer (CRC) needs to be further explored.

Methods

Western blot and immunohistochemistry were employed for detecting B7-H3 protein expression in CRC tissues and cell lines, respectively. Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized for detecting B7-H3 mRNA and miR-128 expression levels. CRC cell lines SW620 and HT29 were used to construct B7-H3 overexpression or knockdown cell models, respectively. Cell counting kit-8 (CCK-8), 5-bromo-2′-deoxyuridine (BrdU), and scratch wound healing assays were employed for evaluating the effects of B7-H3 on CRC cell multiplication and migration. Besides, the regulatory relationship between miR-128 and B7-H3 was validated through dual-luciferase reporter gene assay, qRT-PCR, and western blotting.

Results

B7-H3 expression level was remarkably elevated in CRC tissues and cell lines, and its high expression level was associated with increased tumor size, positive lymph node metastasis, and increased T stage. In CRC cells, B7-H3 overexpression significantly facilitated the cell multiplication and migration, while B7-H3 knockdown worked oppositely. Moreover, B7-H3 was identified as a target of miR-128, and miR-128 negatively regulated B7-H3 expression in CRC cells.

Conclusion

B7-H3 expression is upregulated in CRC tissues and cell lines, and B7-H3 participates in promoting the proliferation and migration of CRC cells. Besides, B7-H3 expression is negatively regulated by miR-128 in CRC.

中文翻译：

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B7-H3，由 miR-128 负调控，促进结直肠癌细胞增殖和迁移

背景

B7 同源物 3 (B7-H3) 是免疫调节配体 B7 家族的成员，在 T 细胞介导的免疫反应中起关键作用。它在多种人类肿瘤中广泛表达，其高表达表明患者预后不良。尽管如此，B7-H3 在结直肠癌 (CRC) 中的作用仍需进一步探索。

方法

Western印迹和免疫组织化学分别用于检测CRC组织和细胞系中B7-H3蛋白的表达。定量实时聚合酶链反应 (qRT-PCR) 用于检测 B7-H3 mRNA 和 miR-128 表达水平。CRC细胞系SW620和HT29分别用于构建B7-H3过表达或敲低细胞模型。细胞计数 kit-8 (CCK-8)、5-bromo-2'-deoxyuridine (BrdU) 和划痕伤口愈合试验用于评估 B7-H3 对 CRC 细胞增殖和迁移的影响。此外，通过双荧光素酶报告基因检测、qRT-PCR和蛋白质印迹验证了miR-128和B7-H3之间的调控关系。

结果

B7-H3在CRC组织和细胞系中的表达水平显着升高，其高表达水平与肿瘤大小增加、淋巴结阳性转移和T分期增加有关。在 CRC 细胞中，B7-H3 过表达显着促进细胞增殖和迁移，而 B7-H3 敲低则相反。此外，B7-H3 被鉴定为 miR-128 的靶标，而 miR-128 在 CRC 细胞中负调控 B7-H3 的表达。

结论

B7-H3在CRC组织和细胞系中表达上调，B7-H3参与促进CRC细胞的增殖和迁移。此外，B7-H3 表达在 CRC 中受到 miR-128 的负调控。