title: Enhanced tumor growth in the remaining lung after major lung resection.
abstract: BACKGROUND
  Pneumonectomy induces active growth of the remaining lung in order to compensate for lost lung tissue. We hypothesized that tumor progression is enhanced in the activated local environment.
  
  
  METHODS
  We examined the effects of mechanical strain on the activation of lung growth and tumor progression in mice. The mechanical strain imposed on the right lung after left pneumonectomy was neutralized by filling the empty space that remained after pneumonectomy with a polypropylene prosthesis.
  
  
  RESULTS
  The neutralization of the strain prevented active lung growth. According to an angiogenesis array, stronger monocyte chemoattractant protein-1 (MCP-1) expression was found in the strain-induced growing lung. The neutralization of the strain attenuated the release of MCP-1 from the lung cells. The intravenous injection of Lewis lung cancer cells resulted in the enhanced development of metastatic foci in the strain-induced growing lung, but the enhanced development was canceled by the neutralization of the strain. An immunohistochemical analysis revealed the prominent accumulation of tumor-associated macrophages in tumors arising in the strain-induced growing lung, and that there was a relationship between the accumulation and the MCP-1 expression status.
  
  
  CONCLUSIONS
  Our results suggested that mechanical lung strain, induced by pulmonary resection, triggers active lung growth, thereby creating a tumor-friendly environment. The modification of that environment, as well as the minimizing of surgical stress, may be a meaningful strategy to improve the therapeutic outcome after lung cancer surgery.
authors.affiliation: Department of Surgery and Clinical Science, Division of Chest Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors.forename: Fumiho
authors.initials: F
authors.lastname: Sano
authors.affiliation: Department of Surgery and Clinical Science, Division of Chest Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan. Electronic address: kaueda@c-able.ne.jp.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Ueda
authors.affiliation: Department of Surgery and Clinical Science, Division of Chest Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Murakami
authors.affiliation: Department of Surgery and Clinical Science, Division of Chest Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors.forename: Masataro
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Department of Surgery and Clinical Science, Division of Chest Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors.forename: Arata
authors.initials: A
authors.lastname: Nishimoto
authors.affiliation: Department of Surgery and Clinical Science, Division of Chest Surgery, Yamaguchi University Graduate School of Medicine, Ube, Yamaguchi, Japan.
authors.forename: Kimikazu
authors.initials: K
authors.lastname: Hamano
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism; D018827:Carcinoma, Lewis Lung / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D018932:Chemokine CCL2 / Q000378:metabolism; D008168:Lung / Q000254:growth & development / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011013:Pneumonectomy / Q000009:adverse effects* / Q000379:methods; D019736:Prostheses and Implants; D059016:Tumor Microenvironment
chemical_list: D014408:Biomarkers, Tumor; D018932:Chemokine CCL2
keywords: Compensatory lung growth; Lung cancer; Microenvironment; Monocyte chemoattractant protein-1; Pulmonary resection