Tacrolimus prevents the dephosphorylation of NF-AT

f DCA’s target enzyme PDHK, the combination of DCA and cisplatin showed evidence of synergy in two of the evaluated cell lines, A427 and HCC-827. The combination of DCA and cisplatin in SKLU-1 and A549 did not show evidence of synergy at relevant doses. Experiments combining DCA and docetaxel did not demonstrate a synergistic effect. Discussion Several preclinical studies and one recent clinical trial have suggested that DCA holds promise as a novel anti-cancer agent. DCA has also received a fair amount of attention in the lay press. Its relatively favorable side effects and low cost make DCA an attractive consideration for patients, though definitive clinical data is lacking. Therefore, we designed this phase II trial to determine the response rate, safety, and tolerability of oral DCA in patients with metastatic breast cancer and advanced stage NSCLC. Our study demonstrated no clinical improvement in 7 subjects with advanced stage cancers treated with DCA. The study was modified to address safety concerns at multiple time points, including amendments to include only patients with baseline ECOG 0 or 1, require a baseline MRI of the brain, and add an additional blood draw. The lack of a control arm makes it difficult to assess the expected frequency of AEs. However, the JCCC DSMB felt that the expected rate was exceeded and they terminated the study. The rate of AEs also exceeded what has been seen in our studies of similar populations. J Cancer Res Clin Oncol. Author manuscript; available in PMC 2015 March 01. Garon et al. Page 7 Oral DCA is rapidly and completely absorbed, but it is also rapidly cleared from the plasma, and repeated dosing is required to obtain sustained plasma levels. The pharmacokinetic clearance of DCA increases as a function of DCA exposure in 20 healthy subjects. This pharmacokinetic profile may be in part due to DCA-mediated inhibition and decrease in expression of GSTz1, the enzyme PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19844694 responsible for dehalogenation of DCA, an important step for its metabolism and excretion. Michelakis et. al. examined activity of DCA in five glioblastoma patients, initially managed with surgery, radiation, and temozolomide, after 15 181223-80-3 price months of DCA therapy and demonstrated radiographic evidence of tumor regression in three of four patients. In the three responsive patients, tissue samples before and after DCA therapy all demonstrated decreased cell proliferation, increased apoptosis, and increased PDH activity. However, therapeutic trough DCA levels were only achieved after several months of consistent dosing. Thus, therapeutic DCA levels may not have been achieved in our patient population in time to prevent disease progression, suggesting that DCA may not be an ideal drug for cancers at risk of rapid progression. In our in vitro analysis of the effect of DCA on NSCLC, significantly enhanced oxygen consumption was observed with 5 mM DCA in the A427 cell line. With respect to the antiproliferative activity of DCA, no significant single agent inhibition or synergistic activity with docetaxel or cisplatin under normoxic conditions was observed. However, we observed a trend towards enhanced growth inhibition when DCA was combined with cisplatin in two of four evaluated cell lines in hypoxic conditions, suggesting that DCA may be an effective agent when given with cisplatin under hypoxic conditions. Similar results have been seen when lung carcinoid cell lines are treated with platinum-based chemotherapy and DCA. A novel chimeric drug g