8-Chloroadenosine 3',5'-Cyclic Monophosphate sodium salt is a site-selective cAMP analog that inhibits various cancer cell lines such as HT29 colorectal cells and ZR-75-1 breast carcinoma, which is due to selective activation of PKA (protein kinase A) isoenzymes. Studies show that 8-Chloroadenosine 3',5'-Cyclic Monophosphate down-regulates the RI α subunit and up-regulates the RII β subunit of cAMP-dependent protein kinases leading to type II holoenzyme-dependent growth inhibition of caner cells such as HL-60. In addition, it is suggested that 8-Chloroadenosine 3',5'-Cyclic Monophosphate can possibly stimulate the antitumor effect of taxanes at micromolar concentrations. Further studies show that mdr-1 mRNA expression is reduced greatly in the presence of 8-Chloroadenosine 3',5'-Cyclic Monophosphate.
