Exiqon A/S, Diagnostic Product Development, Skelstedet 16, 2950 Vedbaek, Denmark.
Clin Exp Metastasis. 2011 Jan;28(1):27-38. doi: 10.1007/s10585-010-9355-7. Epub 2010 Oct 31.
Approximately 25% of all patients with stage II colorectal cancer will experience recurrent disease and subsequently die within 5 years. MicroRNA-21 (miR-21) is upregulated in several cancer types and has been associated with survival in colon cancer. In the present study we developed a robust in situ hybridization assay using high-affinity Locked Nucleic Acid (LNA) probes that specifically detect miR-21 in formalin-fixed paraffin embedded (FFPE) tissue samples. The expression of miR-21 was analyzed by in situ hybridization on 130 stage II colon and 67 stage II rectal cancer specimens. The miR-21 signal was revealed as a blue chromogenic reaction, predominantly observed in fibroblast-like cells located in the stromal compartment of the tumors. The expression levels were measured using image analysis. The miR-21 signal was determined as the total blue area (TB), or the area fraction relative to the nuclear density (TBR) obtained using a red nuclear stain. High TBR (and TB) estimates of miR-21 expression correlated significantly with shorter disease-free survival (p = 0.004, HR = 1.28, 95% CI: 1.06-1.55) in the stage II colon cancer patient group, whereas no significant correlation with disease-free survival was observed in the stage II rectal cancer group. In multivariate analysis both TB and TBR estimates were independent of other clinical parameters (age, gender, total leukocyte count, K-RAS mutational status and MSI). We conclude that miR-21 is primarily a stromal microRNA, which when measured by image analysis identifies a subgroup of stage II colon cancer patients with short disease-free survival.
大约 25%的 II 期结直肠癌患者会出现疾病复发，并在 5 年内死亡。microRNA-21（miR-21）在多种癌症中上调，并与结肠癌的生存相关。在本研究中，我们使用高亲和力的锁核酸（LNA）探针开发了一种稳健的原位杂交检测方法，该方法可特异性检测福尔马林固定石蜡包埋（FFPE）组织样本中的 miR-21。通过原位杂交分析了 130 例 II 期结肠癌和 67 例 II 期直肠癌标本中的 miR-21 表达。miR-21 信号通过纤维母细胞样细胞在肿瘤基质区的蓝色显色反应显示，这些细胞主要位于肿瘤的基质区。使用图像分析测量表达水平。miR-21 信号通过总蓝色面积（TB）或相对核密度（TBR）表示，TBR 通过红色核染色获得。miR-21 表达的高 TBR（和 TB）估计值与 II 期结肠癌患者无病生存率显著相关（p=0.004，HR=1.28，95%CI：1.06-1.55），而在 II 期直肠癌患者中则无显著相关性。在多变量分析中，TB 和 TBR 估计值独立于其他临床参数（年龄、性别、白细胞总数、K-RAS 突变状态和 MSI）。我们得出结论，miR-21 主要是一种基质 microRNA，通过图像分析测量时，可以识别无病生存率较短的 II 期结肠癌患者亚组。
