Published online May 7, 2009. doi: 10.3748/wjg.15.2089
Revised: February 19, 2009
Accepted: February 26, 2009
Published online: May 7, 2009
AIM: To analyze the relevance of the microRNA miR-196a for colorectal oncogenesis.
METHODS: The impact of miR-196a on the restriction targets HoxA7, HoxB8, HoxC8 and HoxD8 was analyzed by reverse transcription polymerase chain reaction (RT-PCR) after transient transfection of SW480 cancer cells. The miR-196a transcription profile in colorectal cancer samples, mucosa samples and diverse cancer cell lines was quantified by RT-PCR. Transiently miR-196a-transfected colorectal cancer cells were used for diverse functional assays in vitro and for a xenograft lung metastasis model in vivo.
RESULTS: HoxA7, HoxB8, HoxC8 and HoxD8 were restricted by miR-196a in a dose-dependent and gene-specific manner. High levels of miR-196a activated the AKT signaling pathway as indicated by increased phosphorylation of AKT. In addition, high levels of miR-196a promoted cancer cell detachment, migration, invasion and chemosensitivity towards platin derivatives but did not impact on proliferation or apoptosis. Furthermore, miR-196a increased the development of lung metastases in mice after tail vein injection.
CONCLUSION: miR-196a exerts a pro-oncogenic influence in colorectal cancer.