There are 4 parts to this study: Part A, monotherapy dose escalation, Part B, monotherapy expansion cohort(s) in PTEN deficient patients at the monotherapy intended therapeutic dose(s) and schedule(s), Part C, AZD8186 added to abiraterone accetate (with prednisone) treatment - dose/ schedule finding followed by expansion phase in PTEN-deficient/mutated or PIK3CB mutated mCRPC and Part D, AZD8186 in combination with AZD2014 (a novel dual mTORC1/2 inibitor) dose/schedule finding followed by expansion phase in PTEN-deficient/mutated or PIK3CB mutated TNBC.