S-Space College of Veterinary Medicine (수의과대학) Dept. of Veterinary Medicine (수의학과) Journal Papers (저널논문_수의학과)
Restoration of mutant K-Ras repressed miR-199b inhibits K-Ras mutant non-small cell lung cancer progression
- Jin, Hua; Jang, Yoonjeong; Cheng, Nian; Li, Qing; Cui, Peng-Fei; Zhou, Zhi-Wei; Jiang, Hu-Lin; Cho, Myung-Haing; Westover, Kenneth D.; Tan, Qun-You; Xu, Cheng-Xiong
- Issue Date
- BioMed Central
- Journal of Experimental & Clinical Cancer Research, Vol.38, p. 165
- Background: miRNAs play crucial role in the progression of K-Ras-mutated nonsmall cell lung cancer (NSCLC). However, most studies have focused on miRNAs that target K-Ras. Here, we investigated miRNAs regulated by mutant K-Ras and their functions. Methods: miRNAs regulated by mutant K-Ras were screened using miRNA arrays. miR-199b expression levels were measured by qRT-PCR. The protein expression levels were measured using Western blot and immunohistochemistry. The effects of miR-199b on NSCLC were examined both in vitro and in vivo by overexpressing or inhibiting miR-199b. DNA methylation was measured by bisulfite sequencing. Results: An inverse correlation was observed between K-Ras mutation status and miR-199b levels in NSCLC specimens and cell lines. The inhibition of miR-199b stimulated NSCLC growth and metastasis, while restoration of miR-199b suppressed K-Ras mutation-driven lung tumorigenesis as well as K-Ras-mutated NSCLC growth and metastasis. miR-199b inactivated ERK and Akt pathways by targeting K-Ras, KSR2, PIK3R1, Akt1, and Rheb1. Furthermore, we determined that mutant K-Ras inhibits miR-199b expression by increasing miR-199b promoter methylation. Conclusion: Our findings suggest that mutant K-Ras plays an oncogenic role through downregulating miR-199b in NSCLC and that overexpression of miR-199b is a novel strategy for the treatment of K-Ras-mutated NSCLC.