RNA-seq was performed in NC, si-TCF12 and overexpression of miR-208b C2C12 cells in triplicate.

C2C12 were cultured in DMEM (Invitrogen) supplemented with 10% FBS (Gibco), 1% Penicillin-Streptomycin (Invitrogen) .C2C12 cells transfected with miR-208b mimic, si-TCF12, or NC were collected for cell cycle analysis 24 hours after transfection.Total RNA from cultured cells was extracted using TRIzol reagent (Invitrogen): Illumina TruSeq RNA Sample Prep Kit (Cat # FC- 122-1001) was used with 1 ug of total RNA for the construction of sequencing libraries. Libraries were prepared according to Illumina's instructions accompanying the DNA Sample Kit (Part # 0801-0303). Briefly, DNA was end-repaired using a combination of T4 DNA polymerase, E. coli DNA Pol I large fragment (Klenow polymerase) and T4 polynucleotide kinase. The blunt, phosphorylated ends were treated with Klenow fragment (32 to 52 exo minus) and dATP to yield a protruding 3- 'A' base for ligation of Illumina's adapters which have a si ngle 'T' base overhang at the 3 'end. After adapter ligation DNA was PCR amplified with Illumina primers for 15 cycles and library fragments of ~ 250 bp (insert plus adaptor and PCR primer sequences) were band isolated from an agarose gel. The purified DNA was captured on an Illumina flow cell for cluster generation. Libraries were sequenced on the Genome Analyzer following the manufacturer's protocols.