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| Status |
Public on Sep 09, 2016 |
| Title |
MiR-196b is epigenetically silenced during the pre-malignant stage of lung carcinogenesis |
| Organism |
Homo sapiens |
| Experiment type |
Expression profiling by array
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| Summary |
MicroRNA silencing by promoter hypermethylation may represent a mechanism by which lung cancer develops and progresses, but the microRNAs involved during malignant transformation are unknown. We previously established a model of pre-malignant lung cancer wherein we treated human bronchial epithelial cells (HBEC) with low doses of tobacco carcinogens. Here, we demonstrate that next-generation sequencing of carcinogen-transformed HBECs treated with the demethylating agent 5-aza-2'deoxycytidine revealed miR-196b and miR-34c-5p to be epigenetic targets. Bisulfite sequencing confirmed dense promoter hypermethylation indicative of silencing in multiple malignant cell lines and primary tumors. Chromatin immunoprecipitation studies further demonstrated an enrichment in repressive histone marks on the miR-196b promoter during HBEC transformation. Restoration of miR-196b expression by transfecting transformed HBECs with specific mimics led to cell cycle arrest mediated in part through transcriptional regulation of the FOS oncogene, and miR-196b re-expression also significantly reduced the growth of tumor xenografts. Luciferase assays demonstrated that forced expression of miR-196b inhibited the FOS promoter and AP-1 reporter activity. Finally, a case-control study revealed that methylation of miR-196b in sputum was strongly associated with lung cancer (OR = 4.7, p<0.001). Collectively, these studies highlight miR-196b as a tumor suppressor whose silencing early in lung carcinogenesis may provide a selective growth advantage to pre-malignant cells. Targeted delivery of miR-196b could therefore serve as a preventive or therapeutic strategy for the management of lung cancer.
HBEC2MBT and H1975 were transiently transfected with a miR-196b mimic and subjected to array-based genome-wide gene expression profiling 48 hours post transfection.
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| Overall design |
Total RNA was isolated with TRIzol from transiently transfected cell lines 48 hours post transfection and subjected to bead array
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| Contributor(s) |
Tellez CS, Juri DE, Do K, Picchi MA, Wang T, Liu G, Spira A, Belinsky SA |
| Citation(s) |
27302168 |
| |
| Submission date |
Apr 06, 2016 |
| Last update date |
Sep 09, 2016 |
| Contact name |
Carmen Tellez |
| E-mail(s) |
ctellez@lrri.org
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| Phone |
505-348-9444
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| Organization name |
Lovelace Respiratory Research Institute
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| Street address |
2425 Ridgecrest Dr. SE
|
| City |
Albuquerque |
| State/province |
NM |
| ZIP/Postal code |
87108 |
| Country |
USA |
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| Platforms (1) |
| GPL10904 |
Illumina HumanHT-12 V4.0 expression beadchip (gene symbol) |
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| Samples (4)
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| Relations |
| BioProject |
PRJNA317578 |
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