Investigation of the regulatory effects of synthesized antisense oligonucleotides on androgen receptor (AR) exon 3 splicing in prostate cancer cells

•SR proteins are validated as key splicing factors promoting exon 3a inclusion.•The recognition of the original 3′ splice site of exon 3 is crucial for modulating AR exon 3/3a splicing.•The polypyrimidine tract region of exon 3a is a potential target for splice-switching therapy.•Antisense oligonucleotide candidate drugs significantly increasing AR23 has been designed and tested in 22Rv1 cells.