Down-regulation of micro-RNA-1 (miR-1) in lung cancer: Suppression of tumorigenic property of lung cancer cells and their sensitization to doxorubicin-induced apoptosis by miR-1

Mohd W. Nasser, Jharna Datta, Gerard Nuovo, Huban Kutay, Tasneem Motiwala, Sarmila Majumder, Bo Wang, Saul Suster, Samson T. Jacob, Kalpana Ghoshal

Research output: Contribution to journalArticle

316 Scopus citations


Micro-RNAs are ∼21-25-nucleotide-long noncoding RNAs that regulate gene expression primarily at the post-transcriptional level in animals. Here, we report that micro-RNA-1 (miR-1), abundant in the cardiac and smooth muscles, is expressed in the lung and is down-regulated in human primary lung cancer tissues and cell lines. In situ hybridization demonstrated localization of miR-1 in bronchial epithelial cells. The tumor suppressor C/EBPα, frequently suppressed in lung cancer, reactivated miR-1 expression in the lung cancer cells. Repressed miR-1 was also activated in lung cancer cells upon treatment with a histone deacetylase inhibitor. These observations led us to examine the antitumorigenic potential of miR-1 in lung cancer cells. Expression of miR-1 in nonexpressing A549 and H1299 cells reversed their tumorigenic properties, such as growth, replication potential, motility/migration, clonogenic survival, and tumor formation in nude mice. Exogenous miR-1 significantly reduced expression of oncogenic targets, such as MET, a receptor tyrosine kinase, and Pim-1, a Ser/Thr kinase, frequently up-regulated in lung cancer. Similarly, the levels of two additional targets, FoxP1, a transcription factor with oncogeneic property, and HDAC4 that represses differentiation-promoting genes, were reduced in miR-1-expressing cells. Conversely, depletion of miR-1 facilitated N417 cell growth with concomitant elevation of these targets. Further, ectopic miR-1 induced apoptosis in A549 cells in response to the potent anticancer drug doxorubicin. Enhanced activation of caspases 3 and 7, cleavage of their substrate PARP-1, and depletion of anti-apoptotic Mcl-1 contributed to the sensitivity of miR-1-expressing cells to doxorubicin. Thus, miR-1 has potential therapeutic application against lung cancers.

Original languageEnglish (US)
Pages (from-to)33394-33405
Number of pages12
JournalJournal of Biological Chemistry
Issue number48
StatePublished - Nov 28 2008


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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