Bai Jinquan, Shi Zhenzhou, Wang Shuting, Pan Hong, Zhang Tong
Department of Radiology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, China.
Front Oncol. 2022 Sep 29;12:950043. doi: 10.3389/fonc.2022.950043. eCollection 2022.
Lung cancer occurs and develops as a result of a complicated process involving numerous genes; therefore, single-gene regulation has a limited therapeutic effect. We discovered that miR-21 expression was high in lung cancer tissues and cells, whereas let-7 expression was low, and it is unclear whether their combined regulation would be superior to therapy involving single regulation. The goal of our research was to investigate this situation and the regulatory mechanism that exists between these genes.
To regulate the levels of miR-21 and let-7 in these two types of lung cancer cells, we transfected miRNA mimics or inhibitors into A549 and H460 cells. Lung cancer cells were tested for proliferation, apoptosis, migration, and invasion. The results were verified using a Western blot and a qRT-PCR assay. Bioinformatics was used to investigate their potential regulatory pathways, and luciferase assays were used to confirm the binding sites.
The expression of miR-21 was increased and that of let-7 was decreased in lung cancer tissues and cells compared with paracancerous tissues and normal lung cells ( < 0.01). Tumor cells were inhibited by downregulation of miR-21 and upregulation of let-7, and cooperative regulation showed a better effect. Upregulation of miR-21 and downregulation of let-7 promoted tumor cells, and this tumor-promoting effect was amplified by cooperative regulation. MiR-21 regulated lung cancer cells directly the Wnt/-catenin pathway, and let-7 exerted its effects the PLAG1/GDH1 pathway. MiR-21 and let-7 cooperated to regulate lung cancer cells the K-ras pathway.
The effect of cooperative regulation of miR-21 and let-7 on lung cancer is greater than that of a single miRNA. MiR-21 and let-7 are important differentially expressed genes in lung cancer that are regulated by the K-ras pathway. As a result, for multigene lung cancer, the cooperative regulation of two miRNAs will provide a new target and direction for lung cancer treatment in the future.
肺癌的发生和发展是一个涉及众多基因的复杂过程；因此，单基因调控的治疗效果有限。我们发现miR-21在肺癌组织和细胞中表达较高，而let-7表达较低，尚不清楚它们的联合调控是否优于单基因调控治疗。我们研究的目的是调查这种情况以及这些基因之间存在的调控机制。
为了调节这两种肺癌细胞中miR-21和let-7的水平，我们将miRNA模拟物或抑制剂转染到A549和H460细胞中。检测肺癌细胞的增殖、凋亡、迁移和侵袭情况。结果通过蛋白质免疫印迹法和实时定量聚合酶链反应检测进行验证。利用生物信息学研究它们潜在的调控途径，并通过荧光素酶报告基因检测来确认结合位点。
与癌旁组织和正常肺细胞相比，肺癌组织和细胞中miR-21表达增加，let-7表达降低（<0.01）。下调miR-21和上调let-7可抑制肿瘤细胞，联合调控显示出更好的效果。上调miR-21和下调let-7可促进肿瘤细胞，这种促肿瘤作用通过联合调控而增强。MiR-21直接通过Wnt/β-连环蛋白途径调控肺癌细胞，let-7通过PLAG1/GDH1途径发挥作用。MiR-21和let-7通过K-ras途径协同调控肺癌细胞。
miR-21和let-7联合调控对肺癌的作用大于单一miRNA。MiR-21和let-7是肺癌中重要的差异表达基因，受K-ras途径调控。因此，对于多基因肺癌，两种miRNA的联合调控将为未来肺癌治疗提供新的靶点和方向。
