Department of Gastroenterology, Ditmanson Medical Foundation Chiayi Christian Hospital, Chiayi, Taiwan.
Department of Pharmacy, College of Pharmacy, China Medical University, Taichung 404, Taiwan.
Anal Cell Pathol (Amst). 2018 Aug 1;2018:8623937. doi: 10.1155/2018/8623937. eCollection 2018.
Human colorectal cancer (CRC) is the third most common cancer; patients with metastatic colorectal cancer (mCRC) show poor prognosis than those with CRC cases. There are no reliable molecular biomarkers for the diagnosis of CRC prognosis except with pathological features. Therefore, it is urgent to develop a biomarker for diagnosis and/or prediction of human CRC. In addition, capping actin protein (CapG) belongs to the gelsolin family and has been reported to contribute on tumor invasion/metastasis in multiple human cancers. Here, we are the first to evaluate the expression of CapG in human CRCs.
To investigate the expression levels of CapG in human tissue array by immunohistochemistry (IHC) staining. Moreover, the mRNA and protein levels were also confirmed in four CRC cell lines and determined using real-time RT-PCR and Western blotting. Finally, a Matrigel transwell invasion assay was used to evaluate the invasion ability in CapG high or low expression cells.
We demonstrated that CapG could be determined in the normal colon tissue and human CRC specimens. However, CapG was significantly overexpressed in the mCRC specimens compared with that in CRC specimens and normal cases. It was also detectable in the four CRC cell lines including mRNA and protein levels. We also found that knockdown of the expression of CapG reduced tumor migration.
In this study, we suggested that CapG could be used as a biomarker for metastatic CRC in the clinical specimens. Moreover, our study demonstrated that CapG might contribute on tumor metastasis in human CRCs.
人类结直肠癌（CRC）是第三大常见癌症；转移性结直肠癌（mCRC）患者的预后比 CRC 患者差。除了病理特征外，目前尚无可靠的分子生物标志物用于 CRC 预后的诊断。因此，迫切需要开发用于诊断和/或预测人 CRC 的生物标志物。此外，帽状肌动蛋白（CapG）属于凝胶蛋白家族，据报道其在多种人类癌症中促进肿瘤侵袭/转移。在这里，我们是第一个评估 CapG 在人类 CRC 中的表达的。
通过免疫组织化学（IHC）染色研究 CapG 在人组织阵列中的表达水平。此外，还通过实时 RT-PCR 和 Western blotting 在四个 CRC 细胞系中证实了 mRNA 和蛋白水平，并进行了测定。最后，使用 Matrigel 转染侵袭测定法评估 CapG 高或低表达细胞的侵袭能力。
我们证明 CapG 可以在正常结肠组织和人类 CRC 标本中确定。然而，CapG 在 mCRC 标本中的表达明显高于 CRC 标本和正常病例。在包括 mRNA 和蛋白水平在内的四个 CRC 细胞系中也可以检测到它。我们还发现 CapG 表达的下调降低了肿瘤迁移。
在这项研究中，我们提出 CapG 可以作为临床标本中转移性 CRC 的生物标志物。此外，我们的研究表明 CapG 可能在人类 CRC 中的肿瘤转移中起作用。
