XBP1 Splicing Assay

RNA extraction and cDNA synthesis were performed as described in qRT-PCR. XBP1 cDNA was amplified by PCR with the PrimeSTAR GXL DNA Polymerase (Takara, Dalian, China). The primer set encompassing the spliced sequences of human XBP1 was as follows: sense primer, 5′-AAACAGAGTAGCAGCTCAGACTGC-3′; antisense primer, 5′-TCCTTCTGGGTAGACCTCTGGGAG-3′. The amplification products were further digested by PstI at 37 °C for 1h, and subsequently separated by DNA electrophoresis on a 2% agarose gel containing Gelred (Biotium Inc, Heyward, California, USA). The primer set for GAPDH amplification was described in qRT-PCR.