Modulation of steroid sulfation by celecoxib-like drugs

描述（由申请人提供）： 越来越多的证据表明，环加氧酶（考克斯）2抑制剂塞来昔布（一种广泛用于治疗骨关节炎和炎性关节炎的药物）对乳腺癌、结肠癌和肺癌具有化学预防和化学治疗作用。除了抑制考克斯-2外，塞来昔布还与磺基转移酶（SULT）相互作用。塞来昔布可刺激人肝胞液和表达的重组人磺基转移酶2A 1（hSULT 2A 1）催化的雌二醇17-硫酸化并抑制其3-硫酸化。刺激雌二醇和相关雌激素的17-硫酸化（通常是次要途径）与抑制3-硫酸化（通常是主要途径）相结合，应导致乳腺可用的活性雌激素量减少。雌二醇-3-硫酸盐（而不是17-硫酸盐）是雌二醇的一种转运形式，被乳腺吸收，在乳腺中水解为雌二醇。这种效果应该是有益的雌激素敏感的乳腺癌通过减少摄取雌激素进入乳房。本研究的长期目标是确定塞来昔布在调节硫酸盐化作用方面的抗癌活性的意义。这可能导致开发用于预防或治疗癌症的新治疗剂。这一小笔赠款申请的重点是定义效果和确定机制。第一个具体目的是检查hSULT 2A 1底物、雌激素、雄激素和胆汁酸的结构特征，这些结构特征使它们对塞来昔布对硫酸盐结合的影响敏感。与hSULT 2A 1一样，将研究塞来昔布对人肝胞质溶胶和表达的重组hSULT 1A 1和1 E1活性的影响。第二个具体目的是研究在存在和不存在雌二醇和塞来昔布的情况下hSULT 2A 1的蛋白质晶体学，以确定底物（雌二醇）和调节剂（塞来昔布）与hSULT 2A 1的分子相互作用，目的是获得有关诱导hSULT 2A 1活性变化的塞来昔布结构特征的信息。未来的研究将确定这种体外确定的效应是否发生在人类志愿者中，并检查塞来昔布相关分子与hSULT 2A 1的相互作用

DESCRIPTION (provided by applicant): Evidence is mounting that the cyclo-oxygenase (COX) 2 inhibitor, celecoxib, a drug that is widely used to treat osteoarthritis and inflammatory arthritis, has chemo-preventive and chemo-therapeutic effects against breast cancer, colon cancer and lung cancer. As well as inhibiting COX-2, celecoxib interacts with sulfotransferases (SULT). Celecoxib stimulates the 17-sulfation and inhibits the 3-sulfation of estradiol catalyzed by human liver cytosol and by expressed recombinant human sulfotransferase 2A1 (hSULT2A1). Stimulation of 17-sulfation (normally a minor pathway) combined with inhibition of 3-sulfation (normally the major pathway) of estradiol and related estrogens should result in a reduction in the amount of active estrogen available to the breast. Estradiol-3-sulfate, but not 17-sulfate, is a transport form of estradiol that is taken up by the breast where it is hydrolyzed to estradiol. This effect should be beneficial for estrogen- sensitive breast cancers by reducing the uptake of estrogen into the breast. The long-term objective of this research is to ascertain the significance of the effect of celecoxib in modulating sulfation, with respect to its anticarcinogenic activity. This could lead to the development of new therapeutic agents for prevention or treatment of cancer. This small grant application is focused on defining the effect and determining the mechanism. The first specific aim is to examine the structural features of hSULT2A1 substrates, estrogens, androgens and bile acids that make them susceptible to the effect of celecoxib on sulfate conjugation. As well as hSULT2A1, human liver cytosol and expressed recombinant hSULT1A1 and 1E1 will be studied for the effect of celecoxib on their activity. The second specific aim is to study the protein crystallography of hSULT2A1 in the presence and absence of estradiol and celecoxib, so as to ascertain the molecular interaction of the substrate (estradiol) and modulator (celecoxib) with hSULT2A1, with the objective of gaining information on the structural features of celecoxib that induce this change in hSULT2A1 activity. Future research will determine if this in vitro defined effect occurs in human volunteers, and examine molecules related to celecoxib for their interaction with hSULT2A1