|Description of the Variability of Drug Transporter Database (VARIDT)|
Drug transporters (DTs) are acknowledged as important determinants governing drug absorption, excretion, and, in many cases, extent of drug entry into target organs (Annu Rev Pharmacol Toxicol. 2012, 52: 249-73). The variability of DTs has thus attracted considerable attentions and broad interests (Nat Rev Drug Discov. 2015, 14: 29-44; Clin Pharmacol Ther. 2019, doi: 10.1002/cpt.1373; Ann Oncol. 2013, 24: 1513-25). There are three aspects of variability: (1) epigenetic regulations and genetic polymorphisms of DTs playing key role in drug resistance (Sci Transl Med. 2016, 8: 348ra97) and clinical treatment optimization (Adv Drug Deliv Rev. 2017, 116: 21-36); (2) species-, tissue-, and disease-specific abundances of DT proteins essential for bridging preclinical study with clinical trial (Mol Pharm. 2015, 12: 4259-69), balancing efficacy and safety (Sci Transl Med. 2016, 8: 352ra109), and predicting disease-drug interaction (Clin Pharmacol Ther. 2018, 104: 900-15), respectively; (3) exogenous factors modulating activity of DTs and leading to the altered disposition of natural substrates and the transported drugs (Adv Drug Deliv Rev. 2015, 86: 17-26; Clin Pharmacol Ther. 2016, 100: 259-67). These variability data are vital for the clinical studies, and the accumulation of such data can lay the foundation for big data-driven precision medicine.
Moreover, due to the extreme complexity of drug dispositions in living organisms, the interplays among different aspects of DT variability have recently emerged to be a new promising research direction of high-impact studies (Drug Resist Updat. 2017, 32: 23-46; Cancer Lett. 2016, 370: 153-64). Particularly, one of the common mechanisms of the cancer multidrug resistance (MDR) is the overexpression of the particular DTs in cancer cells (Cancer Lett. 2016, 370: 153-64), and the developments of exogenous chemical to inhibit the efflux of these DTs are successfully proposed to reverse caner MDR (Drug Resist Updat. 2017, 32: 23-46; Cancer Lett. 2016, 370: 153-64). These and other potential studies require the collectively analyses of multiple data among different aspects of DT variability. However, no database has been available so far to provide the comprehensive information of all aspects of DT variability.
Therefore, the Variability of Drug Transporter Database (VARIDT) was introduced. First, a comprehensive literature review on all drugs approved by U.S. FDA and >1,000 drugs in clinical trial or preclinical research was conducted. Different from the small amount of DTs (~20) well characterized in previous work (Nat Rev Drug Discov. 2010, 9: 215-36), 177 DTs were confirmed for the first time in VARIDT to transport approved drug(s) and 146 DTs were to transport the drug(s) in clinical/preclinical test. Second, for these hundreds of newly confirmed DTs, the VARIDT not only comprehensively provided all three aspect of their variability data but also allowed the mutual connection (interplay) between any two aspects. All in all, the VARIDT is UNIQUE in (1) covering the largest number of DTs confirmed by their corresponding drugs among available knowledge bases, (2) providing for the first time the comprehensive sets of DT variability data, and (3) allowing the interplay analysis among different aspects of DT variability. All diseases in VARIDT were standardized using the latest revision of International Classification of Diseases (ICD-11) to serve comprehensive health management, and the vast majority (~80%) of the confirmed DTs in VARIDT had the data from multiple aspects of variability, which allowed interplays among these aspects. All data are FULLY DOWNLOADABLE .