Figure 2.

DNA methylation is responsible for the upregulation of phosphatase and tensin homolog (PTEN). (A) Reverse transcription-quantitative polymerase chain reaction (qPCR) analysis was performed to determine the expression level of PTEN following transfection of miR-101 or miR-ctrl. (B) Methylation-specific PCR analysis of the PTEN CpG sites in A549 cells following transfection of miR-101 or miR-ctrl. H₂O was used as a negative control. Bands in the ‘M’ and ‘U’ lanes are PCR products obtained with methylation-specific and non-methylation-specific primers, respectively. (C) Western blot analysis was used to assay the expression of PTEN in A549 cells following transfection of miR-101 or its negative control. β-actin was used as a housekeeping control (**P<0.01, Student's t-test).