Ali Mansoor, Singh Navneendra, Yadav Monika, Nayak Satyabrata, Bamezai Rameshwar N K, Singh Rana P
Cancer Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
Cancer Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India; Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India.
Biochem Biophys Res Commun. 2025 Aug 15;775:152182. doi: 10.1016/j.bbrc.2025.152182. Epub 2025 Jun 9.
Breast cancer is one of the most common types of cancer in the world, and triple-negative breast cancer (TNBC) is an extremely aggressive subtype. This study aimed to investigate the efficacy and mechanisms of miR-24-2 against TNBC.
MDA-MB-231 (TNBC), HEK293T and HEK293 cells were used for various assays including cell viability and proliferation, cell migration, and invasion. RT-PCR, immunoblotting, acridine orange-ethidium bromide and DCFDA assays, tumour xenograft, H&E and IHC methods were employed in the study.
miR-24-2 overexpression induced cell death and inhibited clonogenic potential. It also reduced the expression of Slug, Twist1, and Vimentin and inhibited cell invasion and migration. miR-24-2 enhanced apoptosis, ROS production, and expression of pH2A.X (S139) while decreased Chk1, Chk2, and Rad51. miR-24-2 inhibited survival signaling by downregulating Akt, Erk1/2, Bcl-2, and cytochrome c (mitochondrial), and enhancing Bax, cytochrome c (cytosolic), and cleaved-caspase 3. miR-24-2 binds to the coding sequence (CDS) of Akt which was validated at mRNA and protein expression levels. Further, miR-24-2 strongly reduced TNBC tumour volume (58 %, p < 0.01) and weight (54 %, p < 0.001) during 20 days. Tumour immunohistochemistry showed that miR-24-2 decreased proliferation and increased apoptosis. Moreover, increased Bax/Bcl-2 ratio and decreased expression of Akt, PCNA, Chk1, Chk2, and Rad51 by miR-24-2 were found in tumours, validating the findings of in vitro and in vivo tumour models.
Overall, this study finds that miR-24-2 directly targets Akt and plays a significant role in TNBC as a key mechanism for its growth, survival, and progression.
乳腺癌是全球最常见的癌症类型之一，三阴性乳腺癌（TNBC）是一种极具侵袭性的亚型。本研究旨在探讨miR-24-2对TNBC的疗效及作用机制。
使用MDA-MB-231（TNBC）、HEK293T和HEK293细胞进行多种检测，包括细胞活力与增殖、细胞迁移和侵袭。本研究采用了RT-PCR、免疫印迹、吖啶橙-溴化乙锭和DCFDA检测、肿瘤异种移植、苏木精-伊红染色和免疫组化方法。
miR-24-2过表达诱导细胞死亡并抑制克隆形成潜力。它还降低了Slug、Twist1和波形蛋白的表达，并抑制细胞侵袭和迁移。miR-24-2增强了细胞凋亡、活性氧生成以及pH2A.X（S139）的表达，同时降低了Chk1、Chk2和Rad51的表达。miR-24-2通过下调Akt、Erk1/2、Bcl-2和细胞色素c（线粒体）并增强Bax、细胞色素c（胞质）和裂解的半胱天冬酶3来抑制生存信号。miR-24-2与Akt的编码序列（CDS）结合，这在mRNA和蛋白质表达水平上得到了验证。此外，在20天内，miR-24-2使TNBC肿瘤体积显著减小（58%，p<0.01），重量显著减轻（54%，p<0.001）。肿瘤免疫组化显示，miR-24-2降低了增殖并增加了凋亡。此外，在肿瘤中发现miR-24-2使Bax/Bcl-2比值升高，并降低了Akt、PCNA、Chk1、Chk2和Rad51的表达，证实了体外和体内肿瘤模型的研究结果。
总体而言，本研究发现miR-24-2直接靶向Akt，并在TNBC的生长、生存和进展中作为关键机制发挥重要作用。
