Restoration of mutant K-Ras repressed miR-199b inhibits K-Ras mutant non-small cell lung cancer progression

Hua Jin, Yoonjeong Jang, Nian Cheng, Qing Li, Peng Fei Cui, Zhi Wei Zhou, Hu Lin Jiang, Myung Haing Cho, Kenneth D Westover, Qun You Tan, Cheng Xiong Xu

Research output: Contribution to journalArticle

1 Scopus citations

Abstract

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.

Original languageEnglish (US)
Article number165
JournalJournal of Experimental and Clinical Cancer Research
Volume38
Issue number1
DOIs
StatePublished - Apr 15 2019

    Fingerprint

Keywords

  • K-Ras
  • miR-199b
  • Non-small cell lung cancer

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

Cite this