miR-103/107 modulates multidrug resistance in human gastric carcinoma by downregulating Cav-1.

MicroRNAs (miRNAs) are a class of non-protein-coding small RNAs with the capacity to regulate fundamental biological processes essential for cancer initiation and progression. In the present study, we analyzed miRNA expression levels between multidrug-resistant gastric carcinoma cell line SGC7901/ADR and its parent cell line SGC7901 using a miRNA microarray. MiR-103/107 was downregulated compared with parental SGC7901 cells. Overexpression of miR-103/107 sensitized SGC7901/ADR cells to doxorubicin (DOX), as demonstrated by in vitro and in vivo drug sensitivity assay. We further confirmed that miR-103/107 inhibited P-gp function in gastric cancer SGC7901/ADR cells. Finally, we verified that caveolin-1 (Cav-1), a critical component of lipid rafts, was a target of miR-103/107.