Cell and Matrix Research Institute, School of Medicine, Kyungpook National University, Daegu, South Korea.
Biostatistics, Medical Research Collaboration Center in Kyungpook National University Hospital and School of Medicine, Kyungpook National University, Daegu, South Korea.
Thorac Cancer. 2023 Apr;14(11):1012-1020. doi: 10.1111/1759-7714.14838. Epub 2023 Mar 4.
Despite therapeutic advances, lung cancer prognosis remains poor. Loss of heterozygosity (LOH) in the 3p21 region is well documented in lung cancer, but the specific causative genes have not been identified.
Here, we aimed to examine the clinical impact of miR-135a, located in the 3p21 region, in lung cancer. miR-135a expression was assessed using quantitative real-time polymerase chain reaction. LOH was analyzed at microsatellite loci D3S1076 and D3S1478, and promoter methylation status was determined by pyrosequencing of resected samples of primary non-small-cell lung cancer (NSCLC). The regulation of telomerase reverse transcriptase (TERT) was evaluated in lung cancer cells H1299 by luciferase report assays after treatment with miR-135a mimics.
miR-135a was significantly downregulated in squamous cell cancer (SCC) tumor tissues compared to normal tissues (p = 0.001). Low miR-135a expression was more frequent in patients with SCC (p = 2.9 × 10 ) and smokers (p = 0.01). LOH and hypermethylation were detected in 27.8% (37/133) and 17.3% (23/133) of the tumors, respectively. Overall, 36.8% (49/133) of the NSCLC cases harbored either miR-135a LOH or promoter hypermethylation. The frequencies of LOH and hypermethylation were significantly associated with SCCs (p = 2 × 10 ) and late-stage (p = 0.04), respectively. MiR-135a inhibited the relative luciferase activity of psiCHECK2-TERT-3'UTR.
These results suggest that miR-135a may act as a tumor suppressor to play an important role in lung cancer carcinogenesis, which will provide a new insight into the translational value of miR-135a. Further large-scale studies are required to confirm these findings.
尽管治疗取得了进展，但肺癌的预后仍然很差。3p21 区域的杂合性丢失（LOH）在肺癌中已有充分记载，但具体的致病基因尚未确定。
在这里，我们旨在研究位于 3p21 区域的 miR-135a 对肺癌的临床影响。使用定量实时聚合酶链反应评估 miR-135a 的表达。在微卫星位点 D3S1076 和 D3S1478 上分析 LOH，并通过对原发性非小细胞肺癌（NSCLC）的切除样本进行焦磷酸测序来确定启动子甲基化状态。在用 miR-135a 模拟物处理后，通过荧光素酶报告测定评估 miR-135a 对肺癌细胞 H1299 中端粒酶逆转录酶（TERT）的调节。
与正常组织相比，miR-135a 在鳞状细胞癌（SCC）肿瘤组织中显着下调（p=0.001）。在 SCC 患者（p=2.9×10）和吸烟者（p=0.01）中，miR-135a 低表达更为常见。在 27.8%（37/133）和 17.3%（23/133）的肿瘤中分别检测到 LOH 和高甲基化。总体而言，133 例 NSCLC 病例中有 36.8%（49/133）存在 miR-135a LOH 或启动子高甲基化。LOH 和高甲基化的频率与 SCC（p=2×10）和晚期（p=0.04）显着相关。miR-135a 抑制 psiCHECK2-TERT-3'UTR 的相对荧光素酶活性。
这些结果表明，miR-135a 可能作为肿瘤抑制因子发挥作用，在肺癌发生发展中发挥重要作用，这将为 miR-135a 的转化价值提供新的见解。需要进一步的大规模研究来证实这些发现。
