title: Inhibition of miR-191 contributes to radiation-resistance of two lung cancer cell lines by altering autophagy activity.
abstract: BACKGROUND
  Lung cancer is the leading cause of cancer-related morbidity and mortality all over the world. Surgery resection, radiotherapy, chemotherapy, immunotherapy and combined treatments have been discovered and well established for treatments. However, low survival rate of five years after clinical treatments mainly due to recurrence of stress-resistant cancer cells calls for better understanding and new ideas. Our project aimed to understand the forming process of stress resistant lung cancer cells after radiotherapy.
  
  
  METHODS
  Two classic non-small cell lung cancer (NSCLC) cell lines A549 and H1299 initially were radiated with a (137)Cs gamma-ray source with doses ranging from 0 to 12 Gy to generate radiation-resistant cancer cells. 8 Gy of radiation was regard as a standard dosage since it provides effective killing as well as good amount of survivals. The expression levels of autophagy-related proteins including Beclin-1, LC3-II and p62 were studied and measured by both western blot and quantitative real-time polymerase chain reaction (real-time RT-PCR).
  
  
  RESULTS
  Increased Beclin-1, LC3-II and decreased p62 have been observed in radiation-resistant cells indicating elevated autophagy level. Decreased miR-191 in radiation-resistant cells performed by Taqman qRT-PCR also has been seen. Two binding sites between Beclin-1 and miR-191 suggest potential association between.
  
  
  CONCLUSIONS
  It is reasonable to speculate that inhibition of miR-191 expression in lung cancer cells would contribute to the establishment of radiation-resistant cells via mediating cellular autophagy. Therefore, miR-191 is a potential target for therapy in treating radiation-resistant lung cancer.
authors: Department of Respiratory, Tianjin Fifth Central Hospital, 41 Zhejiang Road, Tianjin, China.
authors: Zhenkuan
authors: Z
authors: Liu
authors: Department of Respiratory, Tianjin Fifth Central Hospital, 41 Zhejiang Road, Tianjin, China.
authors: Shaoxiang
authors: S
authors: Huang
keywords: Autophagy; Lung cancer; Radiation-resistant; miR-191