title: Down-regulation of miR-675-5p contributes to tumor progression and development by targeting pro-tumorigenic GPR55 in non-small cell lung cancer.
abstract: BACKGROUND
  microRNAs are small noncoding RNAs that modulate a variety of cellular processes by regulating multiple targets, which can promote or inhibit the development of malignant behaviors. Accumulating evidence suggests that miR-675-5p plays important roles in human carcinogenesis. However, its precise biological role remains largely elusive. This study examined the role of miR-675-5p in non- small cell lung cancer (NSCLC).
  
  
  METHODS
  The expression of miR-675-5p was analyzed by real-time quantitative PCR (qRT-PCR). The effect of miR-675-5p on proliferation was evaluated through MTT and colony formation assays, and cell migration and invasion were evaluated through transwell assays. The expression of target proteins and downstream molecules was analyzed by western blotting and immunohistochemical staining. The luciferase reporter assay was used to assess the target genes of miR-675-5p in non-small cell lung cancer cells.
  
  
  RESULTS
  The expression levels of miR-675-5p in NSCLC tissues were significantly reduced compared to those in adjacent non-cancerous tissues (P < 0.001). The expression of miR-675-5p in patients with non-small cell lung cancer had a negative correlation with lymph node metastasis (P < 0.01) and TNM stage (P < 0.05). Down-regulation of miR-675-5p promoted cell growth, proliferation, colony formation, invasion and migration, and promoted the tumorigenicity graft growth of nude mice in vivo (P < 0.01); whereas up-regulation of miR-675-5p had the contrary effects. The luciferase reporter assay showed that GPR55 was a direct target gene of miR-675-5p. Overexpression of miR-675-5p can lead to the down-regulation of GPR55 and its signaling pathway, whereas the effect can be reversed by down-regulation of miR-675-5p expression.
  
  
  CONCLUSIONS
  miR-675-5p functions as a novel tumor suppressor in NSCLC and the anti-oncogenic activity may involve its inhibition of the target gene GPR55. These findings suggest the possibility for miR-675-5p as a therapeutic target in NSCLC.
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. 714151179@qq.com.
authors.forename: Dan
authors.initials: D
authors.lastname: He
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. 768735234@qq.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. zcf6636169@sina.com.
authors.forename: Chunfang
authors.initials: C
authors.lastname: Zhang
authors.affiliation: College of Medical Sciences, Washington State University Spokane, 412 E.Spokane Falls Boulevard, Spokane, WA, 99202, USA. bin.shan@wsu.edu.
authors.forename: Bin
authors.initials: B
authors.lastname: Shan
authors.affiliation: Faculty of Basic Medical Sciences, College of Medicine, Hunan Normal University, Changsha, 410013, PR China. dengxiyunmed@hunnu.edu.cn.
authors.forename: Xiyun
authors.initials: X
authors.lastname: Deng
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. lb930336@163.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. zhouyanwudream@163.com.
authors.forename: Yanwu
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. 1375266291@qq.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. hongjidong1966@126.com.
authors.forename: Jidong
authors.initials: J
authors.lastname: Hong
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. gaoyang_george@sina.com.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. chenzhuchu@126.com.
authors.forename: Zhuchu
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Key Laboratory of Cancer Proteomics of Chinese Ministry of Health, Institute of Medical Sciences, Xiangya Hospital, Central South University, Xiangya Road 87th, Changsha, 410008, Hunan, PR China. duancjxy@126.com.
authors.forename: Chaojun
authors.initials: C
authors.lastname: Duan
mesh_terms: D000818:Animals; D063646:Carcinogenesis / Q000235:genetics* / Q000473:pathology; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation / Q000235:genetics; D018450:Disease Progression; D015536:Down-Regulation / Q000235:genetics*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D008207:Lymphatic Metastasis / Q000235:genetics / Q000473:pathology; D008297:Male; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D043882:Receptors, Cannabinoid; D043562:Receptors, G-Protein-Coupled / Q000235:genetics*; D015398:Signal Transduction / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics
chemical_list: C524885:GPR55 protein, human; C548379:MIRN675 microRNA, human; D035683:MicroRNAs; D043882:Receptors, Cannabinoid; D043562:Receptors, G-Protein-Coupled