title: TIM-4 promotes the growth of non-small-cell lung cancer in a RGD motif-dependent manner.
abstract: BACKGROUND
  T-cell immunoglobulin domain and mucin domain 4 (TIM-4) is exclusively expressed in antigen-presenting cells and involved in immune regulation. However, the role of TIM-4 expressed in tumour cells remains completely unknown.
  
  
  METHODS
  Immunohistochemistry staining was used to examine TIM-4 or Ki-67 expression in tumour tissues. Real-time PCR or RT-PCR was performed to detect TIM-4 mRNA expression. Lung cancer cell growth and proliferation were conducted by CCK-8 assay and EdU staining. Cell cycle progression was analysed by flow cytometry. The PCNA and cell cycle-related proteins were verified by western blot. Co-IP assay was used to identify the interaction of TIM-4 and integrin αvβ3. The efficacy of TIM-4 in vivo was evaluated using xenograft tumour model.
  
  
  RESULTS
  The expression of TIM-4 in non-small-cell lung cancer (NSCLC) tissues was significantly higher than that of the adjacent tissues. Enhanced TIM-4 expression was negatively correlated with histological differentiation of lung carcinoma and lifespan of patients. Overexpression of TIM-4 promoted lung cancer cell growth and proliferation, and upregulated the expression of PCNA, cyclin A, cyclin B1 and cyclin D1, accompanied by accumulation of lung cancer cells in S phase. Interestingly, Arg-Gly-Asp (RGD) motif mutation abolished the effect of TIM-4 on lung cancer cells, which was further verified by tumour xenografts in mice. Furthermore, we found that TIM-4 interacted with αvβ3 integrin through RGD motif.
  
  
  CONCLUSIONS
  This finding suggests that TIM-4 might be a potential biomarker for NSCLC that promotes lung cancer progression by RGD motif.
authors.affiliation: Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, People's Republic of China.|Institute of Cardiovascular Disease, General Hospital of Ji'nan Military Region, 8 Lashan Road, Ji'nan, Shandong 250022, People's Republic of China.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, People's Republic of China.
authors.forename: Hongxing
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, People's Republic of China.|Department of Packaging, Jinan Blood Centre, 127 Jing Qi Road, Jinan, Shandong 250021, People's Republic of China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, People's Republic of China.
authors.forename: Bing
authors.initials: B
authors.lastname: Liu
authors.affiliation: Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.affiliation: Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, People's Republic of China.
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.affiliation: Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, People's Republic of China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, People's Republic of China.
authors.forename: Chunhong
authors.initials: C
authors.lastname: Ma
authors.affiliation: Department of Immunology, Key Laboratory for Experimental Teratology of Ministry of Education, Shandong Provincial Key Laboratory of Infection & Immunology, Shandong University School of Medicine, 44 Wenhua Xi Road, Jinan, Shandong 250012, People's Republic of China.
authors.forename: Lifen
authors.initials: L
authors.lastname: Gao
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001665:Binding Sites; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000378:metabolism*; D019394:Ki-67 Antigen / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008875:Middle Aged; D009368:Neoplasm Transplantation; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism
chemical_list: D039302:Integrin alphaVbeta3; D019394:Ki-67 Antigen; D008565:Membrane Proteins; D018809:Proliferating Cell Nuclear Antigen; C512411:TIMD4 protein, human