微小RNA-34b及c-Myc在膀胱癌中的作用及验证两者相互作用关系

Role of microRNA-34b and c-Myc in bladder cancer and their interaction

目的分析微小RNA(miR)-34b及c-Myc在膀胱癌中的作用,并验证两者相互作用关系。方法 107例膀胱癌患者,全部患者均行手术治疗,取病理组织及瘤旁组织样本,比较miR-34b及c-Myc在膀胱癌和瘤旁组织、肌层浸润和肌层非浸润及的各病理分级的表达水平,采用荧光素酶法及生物信息学软件分析miR-34b与c-Myc的相互作用关系。结果 miR-34b在膀胱癌中的相对表达水平为(0.0213±0.0061),与瘤旁组织的(0.0563±0.0089)对比差异有统计学意义(P<0.05);c-Myc在膀胱癌中的相对表达水平为(0.484±0.063),与瘤旁组织的(0.216±0.045)对比差异有统计学意义(P<0.05)。miR-34b在45例肌层浸润性膀胱癌中的相对表达水平为(0.0234±0.0026),与62例肌层非浸润性膀胱癌中的(0.0496±0.0075)对比差异有统计学意义(P<0.05);c-Myc在45例肌层浸润性膀胱癌中的相对表达水平为(0.5180±0.0826),与62例肌层非浸润性膀胱癌中的(0.3140±0.0753)对比差异有统计学意义(P<0.05)。miR-34b在低度恶性倾向、低分级、高分级病例的表达水平依次为(0.0364±0.0047)、(0.0219±0.0034)和(0.0102±0.0028),其表达水平随病理分级升高呈现降低趋势,组间对比差异有统计学意义(F=386.732, P<0.05);c-Myc在低度恶性倾向、低分级、高分级病例的表达水平依次为(0.083±0.013)、(0.236±0.032)和(0.571±0.058),其表达水平随病理分级升高呈现上升趋势,组间对比差异有统计学意义(F=106.964, P<0.05)。经生物信息学软件检验发现, c-Myc是miR-34b的直接靶基因,采用荧光素酶法进一步检测后证实,共转染miR-34b的荧光强度(1.035±0.024)au明显低于共转染的c-Myc强度(3.572±0.068)au (P<0.05)。结论 c-Myc是miR-34b的直接靶基因,二者存在密切的相关性,可通过下调c-Myc水平提升miR-34b表达,抑制膀胱细胞癌增殖。

Objective To analyze the role of microRNA-34b(miR) and c-Myc in bladder cancer and their interaction. Methods All 107 patients with bladder cancer were treated with surgery. Pathological and paraneoplastic tissue samples were taken to compare the expression levels of microRNA-34 b and c-Myc in bladder cancer and paraneoplastic tissues, muscular and non-muscular infiltration, and pathological grades. The interaction between miR-34 b and c-Myc was analyzed by luciferase assay and bioinformatics software. Results The relative expression level of microRNA-34 b in bladder cancer was(0.0213±0.0061), which was significantly different from(0.0563±0.0089) in paraneoplastic tissues(P<0.05). The relative expression level of microRNA-34 b in bladder cancer was(0.484±0.063), which was significantly different from(0.216±0.045) in paraneoplastic tissues(P<0.05). The relative expression level of miR-34 b in 45 cases of myometrial invasive bladder cancer was(0.0234±0.0026), and it was significantly different from(0.0496±0.0075) in 62 cases of non-invasive bladder cancer(P<0.05). The relative expression level of c-Myc in 45 cases of myometrial invasive bladder cancer was(0.5180±0.0826), which was statistically significant(0.3140±0.0753) in 62 cases of noninvasive bladder cancer(P<0.05). The expression levels of miR-34 b in low-grade, low-grade, high-grade cases were(0.0364±0.0047),(0.0219±0.0034), and(0.0102±0.0028), and the expression level of the miR-34 b decreased with the increase of pathological grade. Their difference was statistically significant(F=386.732, P<0.05). The expression levels of c-Myc in low-grade, low-grade, high-grade cases were(0.083±0.013),(0.236±0.032), and(0.571±0.058), and their expression levels increased with pathological grade. Their difference between the groups was statistically significant(F=106.964, P<0.05). Bioinformatics software found that c-Myc is a direct target gene of miR-34 b. Further detection by luciferase assay confirmed that the fluorescence intensity(1.035±0.024) au of co-transfected miR-34 b was significantly lower than that of(3.572±0.068) in aucotransfected c-Myc(P<0.05).Conclusion c-Myc is a direct target gene of miR-34 b, and there is a close correlation between them. It can increase the expression of miR-34 b and down-regulate the proliferation of bladder cell carcinoma by down-regulating c-Myc level.