BTB/POZ zinc finger protein ZBTB16 inhibits breast cancer proliferation and metastasis through upregulating ZBTB28 and antagonizing BCL6/ZBTB27
BTB/POZ zinc finger protein ZBTB16 inhibits breast cancer proliferation and metastasis through upregulating ZBTB28 and antagonizing BCL6/ZBTB27
复制标题
BTB/POZ锌指蛋白ZBTB16通过上调ZBTB28、拮抗BCL6/ZBTB27抑制乳腺癌增殖和转移
DOI：
10.1186/s13148-020-00867-9
复制
发表时间：
2020-06-09
影响因子：
5.7
通讯作者：
Xiang, Tingxiu
中科院分区：
文献类型：
--
作者：
He, Jin;Wu, Mingjun;Xiang, Tingxiu
背景乳腺癌仍然迫切需要可靠的诊断和预后标志物。锌指蛋白和含BTB/POZ结构域的家族蛋白（ZBTB）是重要的转录因子，具有癌基因或肿瘤抑制基因的功能。ZBTB 16在乳腺癌中的作用和调节仍有待确定。方法应用逆转录聚合酶链反应（RT-PCR）和甲基化特异性聚合酶链反应（methylation-specific PCR）检测ZBTB 16在乳腺癌细胞系和组织中的表达和甲基化情况。通过细胞活力、CCK 8、Transwell、集落形成和流式细胞术测定来检查ZBTB 16在乳腺癌细胞中的作用。进行异种移植和免疫组织化学分析以确定ZBTB 16对体内肿瘤发生的影响。采用Western blot、qRT-PCR、荧光素酶试验和co-IP进一步研究ZBTB 16的特异性机制。结果ZBTB 16基因在乳腺癌细胞系中表达下调，且与其启动子区CpG甲基化状态相关。ZBTB 16表达的恢复导致诱导G2/M期阻滞和凋亡，抑制迁移和侵袭，逆转EMT，并抑制细胞增殖，在体外和体内。此外，异位表达的ZBTB 16与ZBTB 28或BCL 6/ZBTB 27形成异源二聚体，并通过上调ZBTB 28和拮抗BCL 6的活性来发挥肿瘤抑制作用。结论ZBTB 16基因的低表达与其启动子甲基化有关，恢复ZBTB 16基因的表达可抑制肿瘤的发生。ZBTB 16通过上调ZBTB 28和拮抗BCL 6发挥肿瘤抑制剂的作用。我们的研究结果也支持ZBTB 16作为乳腺癌预后生物标志物的可能性。
Background Breast cancer remains in urgent need of reliable diagnostic and prognostic markers. Zinc finger and BTB/POZ domain-containing family proteins (ZBTBs) are important transcription factors functioning as oncogenes or tumor suppressors. The role and regulation of ZBTB16 in breast cancer remain to be established. Methods Reverse-transcription PCR and methylation-specific PCR were applied to detect expression and methylation ofZBTB16in breast cancer cell lines and tissues. The effects of ZBTB16 in breast cancer cells were examined via cell viability, CCK8, Transwell, colony formation, and flow cytometric assays. Xenografts and immunohistochemistry analyses were conducted to determine the effects of ZBTB16 on tumorigenesis in vivo. The specific mechanisms of ZBTB16 were further investigated using Western blot, qRT-PCR, luciferase assay, and co-IP. Results ZBTB16was frequently downregulated in breast cancer cell lines in correlation with its promoter CpG methylation status. Restoration of ZBTB16 expression led to induction of G2/M phase arrest and apoptosis, inhibition of migration and invasion, reversal of EMT, and suppression of cell proliferation, both in vitro and in vivo. Furthermore, ectopically expressed ZBTB16 formed heterodimers with ZBTB28 or BCL6/ZBTB27 and exerted tumor suppressor effects through upregulation of ZBTB28 and antagonistic activity on BCL6. Conclusions Low expression ofZBTB16is associated with its promoter hypermethylation and restoration of ZBTB16 inhibits tumorigenesis. ZBTB16 functions as a tumor suppressor through upregulating ZBTB28 and antagonizing BCL6. Our findings also support the possibility of ZBTB16 being a prognostic biomarker for breast cancer.