Okumura Tomoyuki, Shimada Yutaka, Moriyama Makoto, Takei Yoshinori, Omura Tetsuya, Sekine Shinichi, Nagata Takuya, Shimizu Kazuharu, Tsukada Kazuhiro
Department of Surgery and Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan.
Department of Nanobio Drug Discovery, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-Ku, Kyoto 606-8501, Japan.
Int J Oncol. 2014 Jun;44(6):1923-32. doi: 10.3892/ijo.2014.2365. Epub 2014 Apr 2.
MicroRNA (miR)-203 has been shown to induce squamous differentiation of epidermal stem cells through the suppression of p63. The aim of this study was to assess the tumor suppressor effect of miR-203 in esophageal squamous cell carcinoma (ESCC) with focus on the regulation of the cell fate decisions and organization of tumor tissue architecture in vivo. Our investigation establishing stable clones from ESCC cell lines with induced miR-203 expression resulted in significant growth inhibition in a mouse xenograft model. Small foci were observed in xenograft tumors with stratified squamous differentiation in conjunction with restored baso-apical polarity. The expression of the basement membrane protein laminine was localized at the center of the foci and the basal cell marker p75NTR was expressed in the innermost layer. The expression of ki67 and p63 was co-localized at the center layers, while involucrin was expressed in the outer layers. Flow cytometry revealed that the p75NTR-positive cells expressing p63 and Bmi1 were well maintained, while the expression of p63 was suppressed in the p75NTR-negative cells. Our cDNA microarray analysis demonstrated the upregulation of genes involved in regulating tissue architecture, such as BMP-4 and ZO-1 in the mir-203 transfectant. Investigation using surgically removed ESCC specimens revealed that the expression of miR-203 significantly correlated with a favorable prognosis. These results demonstrated that miR-203 regulated both basal and supra-basal cell components to induce differentiation with restored epithelial tissue architecture, leading to significant tumor growth inhibition in vivo. Those results suggest the use of miR-203 as a novel therapeutic and diagnostic target in patients with ESCC.
微小RNA（miR）-203已被证明可通过抑制p63诱导表皮干细胞的鳞状分化。本研究的目的是评估miR-203在食管鳞状细胞癌（ESCC）中的肿瘤抑制作用，重点关注体内细胞命运决定的调控和肿瘤组织结构的组织。我们从诱导miR-203表达的ESCC细胞系建立稳定克隆的研究结果显示，在小鼠异种移植模型中显著抑制生长。在异种移植肿瘤中观察到小病灶，伴有分层鳞状分化以及恢复的基底-顶端极性。基底膜蛋白层粘连蛋白的表达定位于病灶中心，基底细胞标志物p75NTR在内层表达。ki67和p63的表达在中间层共定位，而兜甲蛋白在外层表达。流式细胞术显示，表达p63和Bmi1的p75NTR阳性细胞得到良好维持，而p63的表达在p75NTR阴性细胞中受到抑制。我们的cDNA微阵列分析表明，在mir-203转染细胞中，参与调节组织结构的基因如BMP-4和ZO-1上调。使用手术切除的ESCC标本进行的研究表明，miR-203的表达与良好预后显著相关。这些结果表明，miR-203调节基底和基底上层细胞成分以诱导分化并恢复上皮组织结构，从而在体内显著抑制肿瘤生长。这些结果提示miR-203可作为ESCC患者的新型治疗和诊断靶点。
