Knudsen Kirsten Nguyen, Lindebjerg Jan, Nielsen Boye Schnack, Hansen Torben Frøstrup, Sørensen Flemming Brandt
Danish Colorectal Cancer Center South, Vejle Hospital, Part of Lillebaelt Hospital, Kabbeltoft 25, Vejle, Denmark.
Department of Clinical Pathology, Vejle Hospital, Part of Lillebaelt Hospital, Kabbeltoft 25, Vejle, Denmark.
PLoS One. 2017 May 26;12(5):e0178564. doi: 10.1371/journal.pone.0178564. eCollection 2017.
The microRNA-200 (miR-200) family acts as a major suppressor of epithelial-mesenchymal transition (EMT). Impaired miR-200 expression may lead to EMT initiation and eventually cancer dissemination. The presence of tumor budding cells (TBC) is associated with metastasis and poor prognosis, and molecular similarities to EMT indicate that these cells may reflect ongoing EMT. The aim of this study was to investigate the expression of miR-200b in budding cells of colon cancer and the relationship with the EMT-markers E-cadherin, β-catenin and laminin-5γ2.
MATERIAL & METHODS: MiR-200b was investigated by in situ hybridization in 58 cases of stage II (n = 36) and III colon (n = 22) cancers with tumor budding. Expression of E-cadherin, β-catenin and laminin-5γ2 was examined by immunohistochemistry. A multiplex fluorescence assay combining miR-200b with cytokeratin and laminin-5γ2 was employed on a subset of 16 samples.
MiR-200b was downregulated in the TBC at the invasive front of 41 out of 58 (71%) cases. The decline was present in both mismatch satellite stable and instable adenocarcinomas. The majority of cases also showed loss of membranous E-cadherin and increased nuclear β-catenin in the TBC, while laminin-5γ2 expression was upregulated at the invasive front and in the tumor buds of approximately half the adenocarcinomas. However, the miR-200b decline was not statistically associated with the expression of any of the EMT-markers. The miR-200b decline was also documented by multiplex fluorescence. Fourteen out of fifteen cases showed a decrease in miR-200b expression in the majority of the TBC, but no obvious relationship between miR-200b and laminin-5γ2 expression was observed. Conclusion: The findings support the assumption of a miR-200b related downregulation in colon cancer budding cells. Whether miR-200b expression may be of clinical significance awaits further studies.
微小RNA - 200(miR - 200)家族是上皮 - 间质转化(EMT)的主要抑制因子。miR - 200表达受损可能导致EMT启动并最终引发癌症扩散。肿瘤芽生细胞(TBC)的存在与转移及不良预后相关,且其与EMT的分子相似性表明这些细胞可能反映了正在进行的EMT过程。本研究旨在探讨miR - 200b在结肠癌芽生细胞中的表达及其与EMT标志物E - 钙黏蛋白、β - 连环蛋白和层粘连蛋白 - 5γ2的关系。
采用原位杂交技术对58例伴有肿瘤芽生的II期(n = 36)和III期结肠癌(n = 22)病例进行miR - 200b检测。通过免疫组织化学检测E - 钙黏蛋白、β - 连环蛋白和层粘连蛋白 - 5γ2的表达。对16个样本的子集采用将miR - 200b与细胞角蛋白和层粘连蛋白 - 5γ2相结合的多重荧光检测法。
在58例病例中的41例(71%)的侵袭前沿TBC中,miR - 200b表达下调。这种下调在错配卫星稳定型和不稳定型腺癌中均存在。大多数病例的TBC还表现为膜性E - 钙黏蛋白缺失和核内β - 连环蛋白增加,而在大约一半的腺癌中,层粘连蛋白 - 5γ2在侵袭前沿和肿瘤芽中表达上调。然而,miR - 200b的下调与任何EMT标志物的表达均无统计学关联。多重荧光检测也证实了miR - 200b的下调。15例病例中的14例在大多数TBC中miR - 200b表达降低,但未观察到miR - 200b与层粘连蛋白 - 5γ2表达之间存在明显关系。结论:这些发现支持结肠癌芽生细胞中存在与miR - 200b相关的下调这一假设。miR - 200b表达是否具有临床意义有待进一步研究。