We report that alternative RNA splicing of the histone demethylase BHC80 gene promotes prostate adenocarcinoma progression to treatment-induced neuroendocrine prostate cancer (t-NEPC). Functionally, reprogrammed RNA splice variant of BHC80-2 mediates nonepigenetic actions in cytoplasm, to stimulate multiple tumor-promoting cytokines for t-NEPC development androgen independently.