Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA.
Toxicology Program, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA.
Int J Mol Sci. 2022 Mar 8;23(6):2926. doi: 10.3390/ijms23062926.
African American (AA) men exhibit 1.6-fold higher prostate cancer (PCa) incidence and 2.4-fold higher mortality rates compared to European American (EA) men. In addition to socioeconomic factors, emerging evidence suggests that intrinsic biological differences may explain part of PCa disparities. In this study, we applied microRNA (miRNA)-driven bioinformatics to evaluate whether differential miRNA-mRNA regulatory networks play a role in promoting the AA PCa disparities. 10 differentially expressed miRNAs were imported to mirPath V.3 algorithm, leading to identification of 58 signaling pathways differentially regulated in AA PCa versus EA PCa. Among these pathways, we particularly focused on mTOR and VEGF signaling, where we identified 5 reciprocal miRNA-mRNA pairings: miR-34a-5p/ miR-34a-5p/, miR-34a-5p/, miR-99b-5p/ and miR-96-5p/ in AA PCa versus EA PCa. RT-qPCR validation confirmed that miR-34a-5p, miR-99b-5p and were downregulated, while miR-96-5p, , , and were upregulated in AA PCa versus EA PCa cells. Transfection of miRNA mimics/antagomir followed by RT-qPCR and Western blot analysis further verified that , and are negatively regulated by miR-34a-5p, whereas and are negatively regulated by miR-99b-5p and miR-96-5p, respectively, at mRNA and protein levels. Targeting reciprocal pairings by miR-34a-5p mimic, miR-99b-5p mimic or miR-96-5p antagomir downregulates HIF1α, PI3Kβ, mTOR, IGFBP2 but upregulates MAPKAPK2, subsequently reducing cell proliferation and sensitizing docetaxel-induced cytotoxicity in PCa cells. These results suggest that miRNA-mRNA regulatory network plays a critical role in AA PCa disparities, and targeting these core miRNA-mRNA pairings may reduce PCa aggressiveness and overcome the chemoresistance in AA patients.
非裔美国人（AA）男性患前列腺癌（PCa）的发病率比欧洲裔美国人（EA）男性高 1.6 倍，死亡率高 2.4 倍。除了社会经济因素外，新出现的证据表明，内在的生物学差异可能部分解释了 PCa 的差异。在这项研究中，我们应用 miRNA 驱动的生物信息学来评估差异 miRNA-mRNA 调控网络是否在促进 AA PCa 差异中发挥作用。10 个差异表达的 miRNA 被导入 mirPath V.3 算法，导致鉴定出 58 个在 AA PCa 与 EA PCa 中差异调节的信号通路。在这些通路中，我们特别关注 mTOR 和 VEGF 信号通路，在那里我们确定了 5 个相互的 miRNA-mRNA 配对：miR-34a-5p/miR-34a-5p/miR-34a-5p/miR-99b-5p/和 miR-96-5p/在 AA PCa 与 EA PCa 中。RT-qPCR 验证证实，miR-34a-5p、miR-99b-5p 和 在 AA PCa 与 EA PCa 细胞中下调，而 miR-96-5p、、、和 上调。转染 miRNA 模拟物/反义寡核苷酸后进行 RT-qPCR 和 Western blot 分析进一步证实，和 受 miR-34a-5p 负调控，而 和 分别受 miR-99b-5p 和 miR-96-5p 负调控，在 mRNA 和蛋白质水平上。miR-34a-5p 模拟物、miR-99b-5p 模拟物或 miR-96-5p 反义寡核苷酸靶向相互配对可下调 HIF1α、PI3Kβ、mTOR、IGFBP2，但上调 MAPKAPK2，从而降低 PCa 细胞的增殖并敏化多西他赛诱导的细胞毒性。这些结果表明，miRNA-mRNA 调控网络在 AA PCa 差异中起关键作用，靶向这些核心 miRNA-mRNA 配对可能降低 PCa 的侵袭性并克服 AA 患者的化疗耐药性。
