Differential microRNA expression profiles in HCT116 colorectal cancer cell lines located in the lung and colon.

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. The majority of mortalities caused by colorectal cancer are due to metastatic disease. As numerous CRC patients experience metastasis to the liver or lung and fail to respond to curative therapies, intensive research efforts have sought to identify the molecular changes or regulatory mechanisms underlying CRC metastasis. In the present study, a stable CRC cell line, HCT16, overexpressing firefly luciferase was constructed and an in vivo metastasis model was established via intravenous injection of this cell line. Using an imaging system, tumor tissue located in the lung and colon was separated and cells were prepared. The microRNA (miRNA) expression profiles of these lung homing or colon homing cells were assessed and compared. A total of 38 differentially expressed miRNAs were selected and confirmed our previous results; several of these have been reported to be involved in the regulation of cancer progression. However, the remaining miRNAs require further investigation. The present profiling may be the first step toward delineating the differential expression of miRNAs in the CRC cells located in the colon and the lung, enabling the elucidation of the regulation associated with miRNAs in colorectal lung metastases. These miRNAs require further validation and functional analysis to evaluate whether they are important in the pathogenesis of colorectal lung metastases or are adopted as markers to predict colorectal metastasis.