Lin Tsang-Chi, Lin Po-Lin, Cheng Ya-Wen, Wu Tzu-Chin, Chou Ming-Chih, Chen Chih-Yi, Lee Huei
Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan ROC.
Graduate Institute of Cancer Biology and Drug Discovery, Taipei Medical University, Taipei, Taiwan ROC.
Ann Surg Oncol. 2015 Dec;22 Suppl 3:S1532-9. doi: 10.1245/s10434-015-4595-z. Epub 2015 May 20.
MicroRNA (miR)-184 has been reported to have a dual role in human cancers. However, the role of miR-184 in non-small cell lung cancer (NSCLC) remains unclear.
Wild-type or mutant CDC25A promoters were constructed by PCR and site-directed mutagenesis to verify whether miR-184 could inhibit CDC25A expression at post-transcription level. Boyden chamber assay was used to assess whether miR-184 could modulate cell invasiveness via targeting CDC25A and c-Myc. We utilized 124 tumors from NSCLC patients to determine miR-184, miR-21, PDCD4 mRNA, c-Myc mRNA, and CDC25A mRNA expression levels by means of real-time PCR analysis. The prognostic value of CDC25A, c-Myc, and miR-184 on overall survival (OS) and relapse-free survival (RFS) was evaluated by Kaplan-Meier and Cox regression analysis.
MiR-184 suppressed CDC25A expression by enhancing the instability of its mRNA as a result of miR-184 binding to its coding region. An increase in CDC25A expression by means of a reduction in miR-184 promotes cell invasiveness. Moreover, a concomitant increase in CDC25A and c-Myc expression as a result of decreased miR-184 via the miR-21-mediated PDCD4 reduction is responsible for cell invasiveness. Among patients, miR-184 expression in lung tumors was found to correlate negatively with CDC25A mRNA, c-Myc mRNA, and miR-21 expression, but was positively related to PDCD4 mRNA expression. High-miR-184, High-CDC25A, or high-c-Myc mRNA tumors exhibited shorter OS and RFS periods than their counterparts. The worst OS and RFS were observed in low-miR-184/high-CDC25A/high-c-Myc tumors, followed by low-miR-184 /high-CDC25A, low-miR-184/high-c-Myc, high-c-Myc, and high-CDC25A tumors.
MiR-184 as a tumor suppressor miR inhibits cell proliferation and invasion capability via targeting CDC25A and c-Myc. Low miR-184 level may predict worse prognosis in NSCLC patients.
据报道，微小RNA（miR）-184在人类癌症中具有双重作用。然而，miR-184在非小细胞肺癌（NSCLC）中的作用仍不清楚。
通过聚合酶链反应（PCR）和定点诱变构建野生型或突变型细胞分裂周期蛋白25A（CDC25A）启动子，以验证miR-184是否能在转录后水平抑制CDC25A表达。采用博伊登小室试验评估miR-184是否可通过靶向CDC25A和原癌基因c-Myc调节细胞侵袭性。我们利用124例NSCLC患者的肿瘤，通过实时荧光定量PCR分析来确定miR-184、miR-21、程序性细胞死亡蛋白4（PDCD4）信使核糖核酸（mRNA）、c-Myc mRNA和CDC25A mRNA的表达水平。通过Kaplan-Meier法和Cox回归分析评估CDC25A、c-Myc和miR-184对总生存期（OS）和无复发生存期（RFS）的预后价值。
miR-184通过与CDC25A编码区结合，增强其mRNA的不稳定性，从而抑制CDC25A表达。通过降低miR-184水平使CDC25A表达增加可促进细胞侵袭性。此外，miR-184水平降低通过miR-21介导的PDCD4减少导致CDC25A和c-Myc表达同时增加，这与细胞侵袭性有关。在患者中，发现肺肿瘤中miR-184表达与CDC25A mRNA、c-Myc mRNA和miR-21表达呈负相关，但与PDCD4 mRNA表达呈正相关。高miR-184、高CDC25A或高c-Myc mRNA的肿瘤比其对应肿瘤的OS和RFS期更短。在低miR-184/高CDC25A/高c-Myc肿瘤中观察到最差的OS和RFS，其次是低miR-184/高CDC25A、低miR-184/高c-Myc、高c-Myc和高CDC25A肿瘤。
miR-184作为一种肿瘤抑制性miR，通过靶向CDC25A和c-Myc抑制细胞增殖和侵袭能力。低miR-184水平可能预示NSCLC患者预后较差。
