title: [An experimental research on inhibitory action of skeletal muscle conditioned medium on metastases of lung carcinomas].
abstract: OBJECTIVE
  Malignant tumors spread and metastasize in the majority of the organs, but are very rare in skeletal muscles. This study was conducted to explore the effect of organic microenvironment of skeletal muscles on the proliferation of pulmonary large cell carcinomas with different metastatic potential and to investigate the mechanism of the rarity of metastases in skeletal muscles.
  
  
  METHODS
  Primary culture of newborn Wistar rat skeletal muscle cells was established, and the murine skeletal muscle conditioned medium(MMCM)was prepared to test its effect in vitro on pulmonary large cell carcinomas with different metastatic potential (PLA-801C with lower potential and PLA-801D with relatively higher potential) by MTT assay. Adriamycin was used as positive control for MMCM; murine benign renal cells BHK-21 were used as negative control for lung carcinoma cells.
  
  
  RESULTS
  Proliferation of tumor cell lines of both PLA-801C and PLA-801D was significantly restrained when cultured with MMCM, while BHK-21 cells were not affected(P< 0.05). Compared with PLA-801C (significant only in primary MMCM), PLA-801D showed significantly decreased proliferation even when cultured in higher reciprocal of MMCM dilution(1/16 of primary MMCM).
  
  
  CONCLUSIONS
  Skeletal muscle cells could selectively inhibit the proliferation of cancerous cells in vitro while benign cells are not affected. Tumor cells with higher metastatic potential are more sensitive to this effect.
authors.affiliation: Department of Thoracic Surgery, General Hospital of PLA, Beijing, 100853, P.R. China.
authors.forename: Nai-Kang
authors.initials: NK
authors.lastname: Zhou
authors.forename: Meng-Li
authors.initials: ML
authors.lastname: Zheng
authors.forename: Cheng-Hua
authors.initials: CH
authors.lastname: Luo
authors.forename: Chao-Yang
authors.initials: CY
authors.lastname: Liang
authors.forename: Xi
authors.initials: X
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Liu
authors.forename: Yu-E
authors.initials: YE
authors.lastname: Sun
mesh_terms: D000818:Animals; D018287:Carcinoma, Large Cell / Q000473:pathology*; D002455:Cell Division / Q000187:drug effects; D002457:Cell Extracts / Q000494:pharmacology; D017077:Culture Media, Conditioned / Q000494:pharmacology*; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D051379:Mice; D018482:Muscle, Skeletal / Q000737:chemistry*; D009362:Neoplasm Metastasis; D051381:Rats; D017208:Rats, Wistar; D014407:Tumor Cells, Cultured
chemical_list: D002457:Cell Extracts; D017077:Culture Media, Conditioned