Lin28B对三阴性乳腺癌侵袭转移的影响及机制

Effect of Lin28B on invasion and metastasis of triple-negative breast cancer and its mechanism

目的 探讨Lin28B对三阴性乳腺癌侵袭转移的影响并分析其潜在机制。方法 经病理证实的80例三阴性乳腺癌患者、手术治疗后获取癌组织及癌旁组织,采用免疫组织化学法检测癌组织、癌旁组织中Lin28B表达、采用实时荧光定量-PCR(RT-PCR)法检测Let-7家族成员微小RNAs(miRNA)相对表达量,并比较两项指标在不同浸润程度、转移情况癌组织中的表达水平。结果 乳腺癌组织中Lin28B阳性率高于癌旁组织(P <0.05);随着肿瘤浸润深度的增加,乳腺癌组织中Lin28B阳性率依次增加(52.17%、74.36%、88.89%,P <0.05);有远处转移乳腺癌患者的肿瘤组织中Lin28B蛋白阳性率高于无远处转移患者(P <0.05)、有淋巴结转移乳腺癌患者肿瘤组织中Lin28B蛋白阳性率高于无淋巴结转移患者(P <0.05);乳腺癌组织中Let-7家族各成员miRNA相对表达量均低于癌旁组织(P <0.05),随着浸润深度的增加,乳腺癌组织中Let-7家族成员miRNA相对表达量依次降低(P <0.05);乳腺癌有远处转移或淋巴结转移患者的Let-7家族成员miRNA相对表达量低于无转移患者(P <0.05)。结论 Lin28B与三阴性乳腺癌的侵袭及转移相关,其作用机制可能与过表达的Lin28B蛋白靶向调节(下调) Let-7家族成员表达水平有关。

Objective To investigate the effect of Lin28B on invasion and metastasis of triple negative breast cancer and its potential mechanism.Methods Breast cancer tissues and corresponding paracancerous tissues were obtained by surgery from 80 patients with pathologically verified triple-negative breast cancer.Immunohistochemistry(IHC)was used to detect Lin28B expression in cancer tissues and paracancerous tissues.Real-time fluorescent quantitative PCR(RT-qPCR)was applied to detect the relative expression levels of Let-7 miRNA family members.The levels of Lin28B and Let-7 miRNA family members were compared among breast cancer tissues with different degree of invasion and metastasis.Results Lin28B-positive rate in breast cancer tissues was higher than that in paracancerous tissues(P<0.05).Lin28B-positive rate in breast cancer tissues was increased with the depth of invasion(52.17%,74.36%,88.89%;P<0.05).Lin28B-positive rate was higher in breast cancer tissues with distant metastasis than that without distant metastasis(P<0.05),and it was higher in breast cancer tissues with lymph node metastasis than that without lymph node metastasis(P<0.05).The relative expression levels of Let-7 miRNA family members in breast cancer tissues were lower than those in paracancerous tissues(P<0.05).The relative expression levels of Let-7 miRNA family members in breast cancer tissue were decreased with the increase of invasion depth(P<0.05).The relative expression levels of Let-7 miRNA family members in patients with distant metastasis or lymph node metastasis of breast cancer were lower than that in patients without metastasis(P<0.05),Conclusion Lin28B is associated with invasion and metastasis of triple-negative breast cancer,and its mechanism may be related to Lin28B overexpression which downregulates the expression levels of Let-7 family members.