Mice
Total RNA used for RNA-seq assays were extracted from frozen tumor samples using TRIzol RNA kit according to its manufacturers instructions. The quality and concentration of extracted RNA was determined using the 2100 RNA Nano 6000 Assay Kit (Agilent Technologies, CA, USA) and a NanoDrop spectrophotometer, respectively. The cDNA libraries for sequencing were purified through the AMPure XP system and prepared by PCR amplification, then the library quality was evaluated by using the Agilent 2100 system. Finally, the library sequencing was performed with a DNBSEQ instrument by Shenzhen BGI Co. LTD (Shenzhen, China).