Golestan Sajjad, Soltani Bahram M, Jafarzadeh Meisam, Ghaemi Zahra, Nafisi Nahid
Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University Tehran, Tehran, Iran.
Breast Department, Iran University of Medical Sciences, Tehran, Iran.
Funct Integr Genomics. 2023 Jan 17;23(1):40. doi: 10.1007/s10142-023-00965-w.
Identification of the genes and genetic networks involved in breast cancer development is a major need for prevention and therapy. LINC02381 (lncRNA) has already been introduced as a tumor suppressor in colorectal and gastric cancers. Here, we intended to investigate its potential functional effects on breast cancer. In the analysis performed on RNA-Seq and microarray data, the LINC02381 lncRNA was found to be significantly downregulated in the breast tumors and associated with poor survival of the patients. Then, the differential expression of LINC02381 was confirmed in breast tumor tissues and cancer cell lines using RT-qPCR. Overexpression of LINC02381 resulted in reduced IGF1R and p-AKT expression levels which indicates decreased PI3K pathway activity, detected by RT-qPCR and western blotting. At the cellular level, LINC02381 overexpression was followed by a decreased proliferation rate of transfected breast cell lines, detected by PI flow cytometry, RT-qPCR, colony formation, and MTT assays. Consistently, the results of Annexin-V/PI flow cytometry, RT-qPCR, caspase3/7 activity, and AO/EB-H33342/PI dual staining revealed that LINC02381 overexpression induced apoptosis and cell death. The reduced migration rate of these cells was also verified through wound healing assay and RT-qPCR against the EMT-involved genes. Our data show that LINC02381 exerts its tumor suppressor effect at least partly through attenuation of the IGF1R/PI3K/AKT signaling pathway, which originated from IGF1R downregulation.
识别参与乳腺癌发展的基因和基因网络是预防和治疗的一项主要需求。LINC02381（长链非编码RNA）已被引入作为结直肠癌和胃癌中的肿瘤抑制因子。在此，我们旨在研究其对乳腺癌的潜在功能影响。在对RNA测序和微阵列数据进行的分析中，发现LINC02381长链非编码RNA在乳腺肿瘤中显著下调，并与患者的不良生存相关。然后，使用逆转录定量聚合酶链反应（RT-qPCR）在乳腺肿瘤组织和癌细胞系中证实了LINC02381的差异表达。LINC02381的过表达导致胰岛素样生长因子1受体（IGF1R）和磷酸化AKT（p-AKT）表达水平降低，这表明通过RT-qPCR和蛋白质免疫印迹法检测到的磷脂酰肌醇-3激酶（PI3K）信号通路活性降低。在细胞水平上，通过碘化丙啶（PI）流式细胞术、RT-qPCR、集落形成和MTT试验检测到，LINC02381过表达后转染的乳腺细胞系增殖率降低。同样，膜联蛋白V/PI流式细胞术、RT-qPCR、半胱天冬酶3/7活性以及吖啶橙/溴化乙锭-H33342/PI双重染色的结果显示，LINC02381过表达诱导细胞凋亡和细胞死亡。这些细胞迁移率的降低也通过伤口愈合试验和针对上皮-间质转化（EMT）相关基因进行的RT-qPCR得到验证。我们的数据表明，LINC02381至少部分通过减弱源自IGF1R下调的IGF1R/PI3K/AKT信号通路发挥其肿瘤抑制作用。
