Provided are small molecule inhibitors of ubiquitin specific protease 2, 8 and 12 (USP2 and USP8 and USP12) activity and methods for their use in treating cancers. The small molecule inhibitors of the invention are particularly useful in the treatment of non-small cell lung cancers that are resistant to tyrosine kinase inhibitors and in the treatment of prostate cancer that is resistant to AR inhibitor therapy.