Hypoxia-induced downregulation of microRNA-186-5p in endothelial cells promotes non-small cell lung cancer angiogenesis by upregulating protein kinase C alpha

Vivien Becker; Xu Yuan; Anne S Boewe; Emmanuel Ampofo; Elke Ebert; Johannes Hohneck; Rainer M Bohle; Eckart Meese; Yingjun Zhao; Michael D Menger; Matthias W Laschke; Yuan Gu

doi:10.1016/j.omtn.2023.01.015

Hypoxia-induced downregulation of microRNA-186-5p in endothelial cells promotes non-small cell lung cancer angiogenesis by upregulating protein kinase C alpha

Mol Ther Nucleic Acids. 2023 Jan 27:31:421-436. doi: 10.1016/j.omtn.2023.01.015. eCollection 2023 Mar 14.

Authors

Affiliations

¹ Institute for Clinical & Experimental Surgery, Saarland University, 66421 Homburg/Saar, Germany.
² Fudan University Shanghai Cancer Center and Institutes of Biomedical Sciences, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
³ Institute of Pathology, Medical Center, Saarland University, 66421 Homburg/Saar, Germany.
⁴ Institute of Human Genetics, Saarland University, 66421 Homburg/Saar, Germany.

Abstract

The tumor microenvironment stimulates the angiogenic activity of endothelial cells (ECs) to facilitate tumor vascularization, growth, and metastasis. The involvement of microRNA-186-5p (miR-186) in regulating the aberrant activity of tumor-associated ECs has so far not been clarified. In the present study, we demonstrated that miR-186 is significantly downregulated in ECs microdissected from human non-small cell lung cancer (NSCLC) tissues compared with matched non-malignant lung tissues. In vitro analyses of primary human dermal microvascular ECs (HDMECs) exposed to different stimuli indicated that this miR-186 downregulation is triggered by hypoxia via activation of hypoxia-inducible factor 1 alpha (HIF1α). Transfection of HDMECs with miR-186 mimic (miR-186m) significantly inhibited their proliferation, migration, tube formation, and spheroid sprouting. In contrast, miR-186 inhibitor (miR-186i) exerted pro-angiogenic effects. In vivo, endothelial miR-186 overexpression inhibited the vascularization of Matrigel plugs and the initial growth of tumors composed of NSCLC cells (NCI-H460) and HDMECs. Mechanistic analyses revealed that the gene encoding for protein kinase C alpha (PKCα) is a bona fide target of miR-186. Activation of this kinase significantly reversed the miR-186m-repressed angiogenic activity of HDMECs. These findings indicate that downregulation of miR-186 in ECs mediates hypoxia-stimulated NSCLC angiogenesis by upregulating PKCα.

Keywords: ERK; MT: non-coding RNAs; NSCLC angiogenesis; PKCα; endothelial cell; hypoxia; miR-186.