title: Loss of SMAD4 Promotes Lung Metastasis of Colorectal Cancer by Accumulation of CCR1+ Tumor-Associated Neutrophils through CCL15-CCR1 Axis.
abstract: OBJECTIVE
  We have reported loss of SMAD4 promotes expression of CCL15 from colorectal cancer to recruit CCR1+myeloid cells through the CCL15-CCR1 axis, which contributes to invasion and liver metastasis. However, the molecular mechanism of lung metastasis is yet to be elucidated. Our purpose is to determine whether similar mechanism is involved in the lung metastasis of colorectal cancer.
  
  
  METHODS
  In a mouse model, we examined whether SMAD4 could affect the metastatic activity of colorectal cancer cells to the lung through the CCL15-CCR1 axis. We immunohistochemically analyzed expression of SMAD4, CCL15, and CCR1 with 107 clinical specimens of colorectal cancer lung metastases. We also characterized the CCR1+myeloid cells using several cell-type-specific markers.
  
  
  RESULTS
  In a mouse model, CCL15 secreted from SMAD4-deficient colorectal cancer cells recruited CCR1+cells, promoting their metastatic activities to the lung. Immunohistochemical analysis of lung metastases from colorectal cancer patients revealed that CCL15 expression was significantly correlated with loss of SMAD4, and that CCL15-positive metastases recruited approximately 1.9 times more numbers of CCR1+cells than CCL15-negative metastases. Importantly, patients with CCL15-positive metastases showed a significantly shorter relapse-free survival (RFS) than those with CCL15-negative metastases, and multivariate analysis indicated that CCL15 expression was an independent predictor of shorter RFS. Immunofluorescent staining showed that most CCR1+cells around lung metastases were tumor-associated neutrophil, although a minor fraction was granulocytic myeloid-derived suppressor cell.
  
  
  CONCLUSIONS
  CCL15-CCR1 axis may be a therapeutic target to prevent colorectal cancer lung metastasis. CCL15 can be a biomarker indicating poor prognosis of colorectal cancer patients with lung metastases. Clin Cancer Res; 23(3); 833-44. ©2016 AACR.
authors: Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Takamasa
authors: T
authors: Yamamoto
authors: Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan. kkawada@kuhp.kyoto-u.ac.jp.
authors: Kenji
authors: K
authors: Kawada
authors: Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.|Department of Pharmacology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.|Moores UCSD Cancer Center, University of California, San Diego, La Jolla, California.
authors: Yoshiro
authors: Y
authors: Itatani
authors: Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Susumu
authors: S
authors: Inamoto
authors: Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Ryosuke
authors: R
authors: Okamura
authors: Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Masayoshi
authors: M
authors: Iwamoto
authors: Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Ei
authors: E
authors: Miyamoto
authors: Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Toyofumi F
authors: TF
authors: Chen-Yoshikawa
authors: Department of Transfusion Medicine and Cell Therapy, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Hideyo
authors: H
authors: Hirai
authors: Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Suguru
authors: S
authors: Hasegawa
authors: Department of Thoracic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Hiroshi
authors: H
authors: Date
authors: Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.|Department of Pharmacology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Makoto M
authors: MM
authors: Taketo
authors: Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors: Yoshiharu
authors: Y
authors: Sakai
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement; D019742:Chemokines, CC / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D064593:Heterografts; D006801:Humans; D008175:Lung Neoplasms / Q000276:immunology / Q000378:metabolism / Q000556:secondary*; D019402:Macrophage Inflammatory Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008819:Mice, Nude; D016513:Mice, SCID; D022423:Myeloid Cells / Q000378:metabolism; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D020556:Neutrophil Infiltration; D011379:Prognosis; D016016:Proportional Hazards Models; D054389:Receptors, CCR1 / Q000502:physiology*; D051901:Smad4 Protein / Q000172:deficiency* / Q000502:physiology
chemical_list: C108814:CCL15 protein, human; C515300:CCR1 protein, human; D019742:Chemokines, CC; D019402:Macrophage Inflammatory Proteins; D009363:Neoplasm Proteins; D054389:Receptors, CCR1; C497796:SMAD4 protein, human; D051901:Smad4 Protein