Department of Colorectal Surgery, the First Affiliated Hospital, College of Medicine, Zhejiang University, No. 79, Qingchun Road, Xiacheng District, Hangzhou City, 310003, Zhejiang Province, China.
World J Surg Oncol. 2020 Dec 10;18(1):328. doi: 10.1186/s12957-020-02106-0.
The alkB homolog 2, alpha-ketoglutarate-dependent dioxygenase (ALKBH2) gene is involved in DNA repair and is expressed in different types of malignancies. However, the role of ALKBH2 in colorectal carcinoma (CRC) remains unclear. This study aimed to explore the potential mechanism of ALKBH2 and its function in CRC.
The expression levels of ALKBH2 in CRC tissues and cells were determined by qRT-PCR. Following that, the role of ALKBH2 in cell proliferation, invasion, and epithelial-mesenchymal transition (EMT) in CRC cells (Caco-2 and LOVO) were assessed by Cell Counting Kit-8 (CCK-8), transwell assays, and Western blotting, respectively. The effect of ALKBH2 on B cell-specific Moloney murine leukemia virus integration site 1 (BMI1) and downstream NF-κB pathway was determined by Western blotting and luciferase reporter assay.
The expression of ALKBH2 was significantly upregulated both in CRC tissues and cells. Further experiments demonstrated that reduction of ALKBH2 suppressed Caco-2 and LOVO cell proliferation and invasion. Moreover, ALKBH2 knockdown also suppressed EMT, which increased E-cadherin expression and reduced N-cadherin expression. Besides, ALKBH2 silencing inhibited BMI1 expression and reduced nuclear accumulation of the NF-κB p65 protein, as well as the luciferase activity of NF-κB p65. Upregulation of BMI1 reversed the effect of ALKBH2 knockdown on the proliferation and invasion in CRC cells.
Our findings suggest that suppression of ALKBH2 alleviates malignancy in CRC by regulating BMI1-mediated activation of NF-κB pathway. ALKBH2 may serve as a potential treatment target for human CRC.
α-酮戊二酸依赖的双加氧酶（ALKBH2）基因的 alkB 同源物参与 DNA 修复，并在不同类型的恶性肿瘤中表达。然而，ALKBH2 在结直肠癌（CRC）中的作用尚不清楚。本研究旨在探讨 ALKBH2 的潜在机制及其在 CRC 中的功能。
通过 qRT-PCR 测定 CRC 组织和细胞中 ALKBH2 的表达水平。然后，通过细胞计数试剂盒-8（CCK-8）、Transwell 测定和 Western blot 分别评估 ALKBH2 对 CRC 细胞（Caco-2 和 LOVO）增殖、侵袭和上皮间质转化（EMT）的作用。通过 Western blot 和荧光素酶报告基因测定确定 ALKBH2 对 B 细胞特异性 Moloney 鼠白血病病毒整合位点 1（BMI1）和下游 NF-κB 通路的影响。
ALKBH2 的表达在 CRC 组织和细胞中均显著上调。进一步的实验表明，降低 ALKBH2 抑制了 Caco-2 和 LOVO 细胞的增殖和侵袭。此外，ALKBH2 敲低还抑制了 EMT，增加了 E-钙粘蛋白的表达，降低了 N-钙粘蛋白的表达。此外，ALKBH2 沉默抑制了 BMI1 的表达，并减少了 NF-κB p65 蛋白的核积累，以及 NF-κB p65 的荧光素酶活性。BMI1 的上调逆转了 ALKBH2 敲低对 CRC 细胞增殖和侵袭的影响。
我们的研究结果表明，抑制 ALKBH2 通过调节 BMI1 介导的 NF-κB 通路的激活来减轻 CRC 的恶性程度。ALKBH2 可能成为人类 CRC 的潜在治疗靶点。
