PO.MCB10.01 · 分子与细胞生物学
褪黑素和雌二醇对三阴性乳腺癌细胞中let-7家族成员的作用
Melatonin and estradiol action on let-7 family members in triple-negative breast cancer cells
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
let-7家族广受研究的抑癌miRNA通过调控多条信号通路参与众多细胞过程。它们具有相同的种子序列，而茎环区各不相同。let-7家族调控细胞中关键的生理功能。然而，其低表达常被发现，并与三阴性乳腺癌（BC）中的细胞增殖、迁移和转移相关。尽管MDA-MB231 BC细胞系为三阴性，但已证实其表达雌激素受体β。Let-7与雌激素存在调控关系，作为雌激素受体的负调控因子。let-7表达的恢复或重建似乎是预防乳腺癌生长和发展的关键。在此背景下，褪黑素（Mel）因其拮抗肿瘤特征的多样且重要的机制而受到关注，这些机制涉及对差异miRNA表达的调控。研究表明，Mel在某些情境下可改变let-7家族部分成员的表达。目的：我们旨在展示Mel和17β-雌二醇（E2）处理对三阴性BC增殖的影响，并评估let-7家族六个成员（let-7a/b/c/g/i/f）的表达谱。方法：用3 mM Mel和100 nM E2处理MDA-MB231细胞，并联合两种药物（ME2），每日更换，最长至96h。评估处理细胞的增殖情况。提取RNA并进行逆转录。开展RT-PCR以检测选定的let-7家族成员。结果：我们的初步结果显示，在Mel和ME2处理后，该细胞系的增殖实验中出现显著下降。细胞在Mel和ME2处理72h时呈现较低的增殖率。Mel处理导致let-7c/g/f表达轻度且显著上升（倍数分别为1.939、1.132、1.624），且let-7c/g在ME2相关处理下也显示更高表达。与CC和E2相比，ME2处理的细胞显示let-7b/i/f显著上升（倍数分别为1.112、1.123、1.506）。与CC相比，let-7c（倍数：0.879）呈现显著下降。此外，在E2处理的细胞中观察到let-7a/b/g/i的较低表达（倍数分别为0.707、0.823、0.662、0.759）。结论：我们的结果表明，Mel可通过调控特定miRNA最小化E2的作用并抑制三阴性BC细胞的增殖。它似乎能恢复三阴性BC中let-7家族抑癌miRNA的表达。资助方：FAPESP 2025/08621-1、2022/04174-2和2018/24224-9，以及CNPq 444345/2024-8。
查看英文原文 English abstract
The widely studied tumor suppressor miRNAs of the let-7 family are involved in many cellular processes through the regulation of several signaling pathways. They shared identical seed sequences and have variable stem-loop regions. The let-7 family regulates crucial physiological functions in cells. However, low expression is frequently found, and it was associated with cell proliferation, migration, and metastasis in triple-negative breast cancer (BC). Although the MDA-MB231 BC cell line is triple-negative, it has been shown to express estrogen receptor beta. Let-7 has a regulatory relationship with estrogen, acting as a negative regulator of estrogen receptors. The recovery or restoration of let-7 expression seems to be a key point to prevent breast cancer growth and development. In this context, melatonin (Mel) has gained notoriety due to its versatile and essential mechanisms for antagonizing tumor features, which involve modulation of differential miRNA expression. Studies have demonstrated that Mel can alter the expression of some members of the let-7 family in some contexts. Objective: We aimed to demonstrate the effects of Mel and 17beta-estradiol (E2) treatments on the proliferation of triple-negative BC and assess the expression profile of six let-7 family members (let-7a/b/c/g/i/f). Methods: MDA-MB231 cells were treated with 3 mM Mel and 100 nM E2, and the two drugs were combined (ME2) and were replaced daily for up to 96h. Cell proliferation was evaluated in treated cells. RNAs were extracted, and reverse transcription was performed. RT-PCR was carried out for the detection of selected let-7 family members. Results: Our preliminary results showed a significant decrease in the proliferation assay in the cell line after Mel and ME2 treatments. Cells presented a lower rate of proliferation at 72h of Mel and ME2 treatments. Mel treatment leads to slightly and significantly increased expression of let-7c/g/f (Fold:1.939; 1.132; 1.624, respectively), and the let-7c/g also showed higher expression related to ME2. Cells treated with ME2 showed a significant increase of let-7b/i/f (Fold:1.112; 1.123; 1.506, respectively) compared to CC and E2. Let-7c (Fold: 0.879) presented a significant decrease compared to CC. Additionally, lower expression of let-7a/b/g/i (Fold: 0.707; 0.823; 0.662; 0.759, respectively) was observed in cells treated with E2. Conclusion: Our results indicate that Mel can minimize E2 effects and inhibit the proliferation of triple-negative BC cells through the regulation of specific miRNAs. It seems to recover the expression of tumor suppressor miRNAs of the let-7 family in triple-negative BC. Supported by: FAPESP 2025/08621-1, 2022/04174-2, and 2018/24224-9, and CNPq 444345/2024-8.
利益披露 Disclosure
B. C. De Almeida,
FAPESP 2025/08621-1 ).
FAPESP 2022/04174-2 ).
FAPESP 2018/24224-9 ).
CNPq 444345/2024-8 ).
K. P. Ferreira, None.
J. Soares-Júnior,
FAPESP 2018/24224-9 ).
K. Candido Carvalho, None.
E. Chada Baracat,
CNPq 444345/2024-8 ).