miR-145-5p inhibits tumor occurrence and metastasis through the NF-κB signaling pathway by targeting TLR4 in malignant melanoma

Canhui Jin; Aihong Wang; Linbo Liu; Gongping Wang; Guangshuai Li; Zhaofeng Han

doi:10.1002/jcb.28388

miR-145-5p inhibits tumor occurrence and metastasis through the NF-κB signaling pathway by targeting TLR4 in malignant melanoma

J Cell Biochem. 2019 Jul;120(7):11115-11126. doi: 10.1002/jcb.28388. Epub 2019 Jan 30.

Authors

Canhui Jin¹, Aihong Wang², Linbo Liu¹, Gongping Wang³, Guangshuai Li¹, Zhaofeng Han¹

Affiliations

¹ Department of Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
² Department of Gynecologic Oncology, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, Henan, China.
³ Department of Gastrointestinal Tumor Surgery, The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, Henan, China.

PMID: 30701576
DOI: 10.1002/jcb.28388

Abstract

Compelling evidence shows that deregulated microRNAs (miRNAs) are important regulators in the progression of melanoma. miR-145-5p has been suggested to exhibit antitumorigenic activity in melanoma. However, the molecular mechanism underlying the biological activity of miR-145-5p in melanoma remains to be further understood. Herein, quantitative real-time polymerase chain reaction was used to examine the miR-145-5p expression in malignant melanoma tissues and cells. The interaction between miR-145-5p and toll-like receptor 4 (TLR4) was explored by bioinformatics analyses, luciferase reporter assay, and Western blot. The effects of miR-145-5p or combined with TLR4 on cell proliferation, colony formation, migration, and invasion abilities were investigated by (4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, colony formation, wound healing, and transwell assays, respectively. The melanoma xenograft tumor models were established to determine the biological activity of miR-145-5p in melanoma in vivo. In addition, the changes of the nuclear factor kappa B (NF-κB) pathway were analyzed by detecting the NF-κB activity and the NF-κB p65 protein level. We observed that the miR-145-5p expression was underexpressed in melanoma tissues and cells. miR-145-5p suppressed the TLR4 expression by binding to its 3'untranslated region in melanoma cells. Moreover, TLR4 overexpression abolished the inhibition of cell proliferation, colony formation, migration, and invasion abilities induced by miR-145-5p in melanoma cells. Meanwhile, miR-145-5p was confirmed to restrain melanoma tumor growth in vivo by targeting TLR4. Furthermore, miR-145-5p overexpression inactivated the NF-κB pathway in melanoma in vitro and in vivo, which was reversed by TLR4 overexpression. We concluded that miR-145-5p hindered the occurrence and metastasis of melanoma cells in vitro and in vivo by targeting TLR4 via inactivation of the NF-κB pathway.

Keywords: melanoma; miR-145-5p; the nuclear factor kappa B (NF-κB) pathway; toll-like receptor 4 (TLR4).