miR-29a在宫颈癌组织中的表达及其上调后对宫颈癌细胞恶性生物学行为的影响

Expression of miR-29a in cervical cancer and effect of miR-29a up-regulation on malignant biologic behaviors of cervical cancer cells

摘要:

目的检测微小RNA（miR）-29a 在宫颈癌组织和不同种类宫颈癌细胞系中的表达情况及其上调后对宫颈癌SiHa细胞增殖、凋亡、侵袭及迁移等恶性生物学行为的影响。方法①组织标本检测：收集2014 年7 月-2016 年7 月西南医科大学附属医院活检或手术切除的宫颈组织标本160 例，采用实时荧光定量聚合酶链反应（qRT-PCR）检测miR-29a 的表达情况，并分析宫颈癌组织中miR-29a 的表达与临床病理特征的关系。②细胞学实验：采用qRT-PCR检测miR-29a在不同种类的人宫颈癌细胞系（SiHa、HeLa、Caski及C33a）和人正常宫颈细胞系Ect1/E6E7中的表达水平，选取miR-29a表达最低的宫颈癌细胞系SiHa进行后续研究，使用miR-29a mimics转染SiHa细胞，qRT-PCR检测转染后细胞miR-29a 的表达变化，CCK-8 法检测转染后细胞增殖活力的变化，流式细胞仪检测转染后细胞凋亡率的变化，Transwell实验检测转染后细胞迁移和侵袭能力的变化。结果宫颈鳞癌组织中miR-29a 表达低于HSIL、LSIL及正常宫颈组织（p <0.05）；HSIL组织中miR-29a表达低于LSIL及正常宫颈组织（p <0.05），LSIL与正常宫颈组织间miR-29a的表达差异无统计学意义（p >0.05）。宫颈鳞癌组织中miR-29a的表达与患者临床分期和淋巴结转移密切相关（p <0.05）。miR-29a在人宫颈癌细胞系（SiHa、HeLa、Caski和C33a）中的表达低于人正常宫颈细胞系Ect1/E6E7（p <0.05）。SiHa细胞转染miR-29a mimics后，miR-29a表达水平增高（p <0.05），细胞增殖活力降低（p <0.05），细胞凋亡率增高（p <0.05），细胞迁移和侵袭能力下降（p <0.05）。结论miR-29a在宫颈癌组织和细胞中均呈低表达，上调miR-29a的表达能够抑制宫颈癌SiHa细胞的增殖及侵袭迁移能力，促进细胞的凋亡。

Abstract:

Objective To investigate the expression of miR-29a in specimens and cells of cervical cancer and explore the effect of up -regulafion of miR -29a expression on proliferation, apoptosis, invasion and migration of cervical cancer cells further. Methods Totally 160 cases of biopsy or surgical specimens were collected in the Affiliated Hospital of Southwest Medical University from July 2014 to July 2016, including 80 cases of cervical cancer, 40 cases of high-grade squamous intraepithelial lesion (HSIL), 20 cases of low-grade squamous intraepithelial lesion (LSIL) and 20 cases of normal cenix. The expression levels of miR-29a indifferent cervical tissues were examined by qRT -PCR. The correlations of miR -29a expression with the clinicopathological parameters of patients were analyzed. The expressions of miR-29a in four cervical cancer cell lines (SiHa, HeLa, Caski, C33a) and one normal cervical cell line Ect1/E6E7 were also examined by qRT-PCR. SiHa cells with the lowest expression of miR-29a were selected in the follow-up studies. SiHa cells were transfected with miR-29a mimics, and the expression of miR-29a in transfected cells was detected by qRT-PCR. CCK-8 assay, flowcytometry and Transwell assay were used to analyze the effect of miR-29a mimics on the proliferation, apoptosis, invasion and migration of SiHa cells. Results The expression of miR-29a in cervical squamous cancer was lower than that in HSIL, LSIL and normal cervical tissue (p < 0.05), and the expression of miR-29a in HSIL was lower than that in LSIL and normal cervical tissue (p < 0.05), while there was no significant difference between LSIL and normal cervical tissues (p > 0.05). The expression level of miR-29a in cervical squamous cancer was correlated with clinical stage and lymph node metastasis (p <0.05). The expression of miR-29a in cervical cancer cell lines was lower than that in normal cervical cell line (p < 0.05). After transfection with miR-29a mimics, the expression of miR-29a was significantly increased(p < 0.05), the proliferation activity was significantly decreased (p < 0.05), the apoptosis rate was significantly increased (p < 0.05), and the cell migration and invasion abilities in SiHa cells were significantly decreased (p <0.05). Conclusions The expression of miR-29a significantly decreases in cervical cancer tissues and cells.Up-regulation of miR-29a can inhibit proliferation, migration and invasion, and promote apoptosis in SiHa cells.