MiR-199a-5p loss up-regulated DDR1 aggravated colorectal cancer by activating epithelial-to-mesenchymal transition related signaling.
BACKGROUND
Discoidin domain receptors1 (DDR1) is associated with tumor progression, and its dysregulated expression has been observed in many cancers.


OBJECTIVE
We aim to explore molecular mechanism underlying the role of DDR1 in colorectal cancer development.


METHODS
Immunohistochemistry and Western blot were applied to examine the DDR1 expression. Real-time RT-PCR and Western blot were performed to determine the expression of miR-199a-5p and DDR1. Luciferase reporter assay was used to determine whether DDR1 was a target of miR-199a-5p. Effects of miR-199a-5p and DDR1 on colorectal cell proliferation, colony formation, cell cycle progression, invasion and migration were then investigated. Western blot was used to determine the relative signal pathways.


RESULTS
Increased DDR1 and decreased miR-199a-5p expression coexisted in CRC, knockdown of DDR1 or overexpression of miR-199a-5p both resulted in reduced colony formation, invasive and migratory capabilities of human CRC LOVE1 and LOVO cells. It was also found that overexpression of miR-199a-5p led to decreased DDR1, MMP2, N-cadherin and vimentin expression and increased E-cadherin expression in both CRC cell lines. However, down-regulation of miR-199a-5p resulted in the opposite effects. Dual luciferase reporter assay confirmed that miR-199a-5p could directly target DDR1 through binding to its 3'-UTR.


CONCLUSIONS
Our findings indicated that up-regulation of DDR1 induced by miR-199a-5p down-regulation may contribute to the development and progression of CRC, and this effect may be associated with increased invasiveness, at least in part, via activating the EMT-related signaling.
Department of Colorectal Surgery, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, 283 Tongzipo Road, Yuelu District, Changsha, 410013, Hunan, China, 787403663@qq.com.
Yingbin
Y
Hu
Jingshi
J
Liu
Bonian
B
Jiang
Juying
J
Chen
Zhongpin
Z
Fu
Fei
F
Bai
Jiarui
J
Jiang
Ziyuan
Z
Tang
D015820:Cadherins / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000070819:Discoidin Domain Receptor 1; D015536:Down-Regulation / Q000235:genetics; D004847:Epithelial Cells; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics / Q000502:physiology*; D005822:Genetic Vectors; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D014162:Transfection; D014410:Tumor Stem Cell Assay; D015854:Up-Regulation / Q000235:genetics; D014746:Vimentin / Q000378:metabolism
D015820:Cadherins; D035683:MicroRNAs; D012333:RNA, Messenger; D014746:Vimentin; C531408:mirn199 microRNA, human; C092030:DDR1 protein, human; D000070819:Discoidin Domain Receptor 1; D020794:Receptor Protein-Tyrosine Kinases; D020778:Matrix Metalloproteinase 2