Anti-SULT1C2 monoclonal antibody, clone 3G6

Cytosolic sulfotransferase 1C2 (SULT1C2) is expressed in the kidney, stomach, and liver of rats; however, the mechanisms regulating expression of this enzyme are not known. We evaluated transcriptional regulation of SULT1C2 by mevalonate (MVA)-derived intermediates in primary cultured rat hepatocytes using several cholesterol synthesis inhibitors. Blocking production of mevalonate with the 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor pravastatin (30 mu M), reduced SULT1C2 mRNA content by similar to 40% whereas the squalene synthase inhibitor squalestatin (SQ1, 0.1 mM), which causes accumulation of nonsterol isoprenoids, increased mRNA content by 4-fold. Treatment with MVA (10 mM) strongly induced SULT1C2 mRNA by 12-fold, and this effect was blocked by inhibiting squalene epoxidase but not by more distal cholesterol inhibitors, indicating the effects of MVA are mediated by postsqualene metabolites. Using rapid amplification of cDNA ends (RACE), we characterized the 59 end of SULT1C2 mRNA and used this information to generate constructs for promoter analysis. SQ1 and MVA increased reporter activity by similar to 1.6- and 3-fold, respectively, from a construct beginning 49 base pairs (bp) upstream from the longest 5'-RACE product (-3140:-49). Sequence deletions from this construct revealed a hepatocyte nuclear factor 1 (HNF1) element (-2558), and mutation of this element reduced basal (75%) and MVA-induced (30%) reporter activity and attenuated promoter activation following overexpression of HNF1 alpha or 1 beta. However, the effects of SQ1 were localized to a more proximal promoter region (-281:-49). Collectively, our findings demonstrate that cholesterol biosynthetic intermediates influence SULT1C2 expression in rat primary hepatocytes. Further, HNF1 appears to play an important role in mediating basal and MVA-induced SULT1C2 transcription.

The anticancer agent docetaxel shows significant inter-individual variation in its pharmacokinetic and toxicity profile. Thalidomide is an active anticancer agent and also shows wide pharmacological variation. Past pharmacogenetic research has not explained this variation. Patients with prostate cancer enrolled in a randomized phase II trial using docetaxel and thalidomide versus docetaxel alone were genotyped using the Affymetrix DMET 1.0 platform, which tests for 1256 genetic variations in 170 drug disposition genes. Genetic polymorphisms were analyzed for associations with clinical response and toxicity. In all, 10 single-nucleotide polymorphisms (SNPs) in three genes were potentially associated with response to therapy: peroxisome proliferator-activated receptor-delta (PPAR-delta), sulfotransferase family, cytosolic, 1C, member 2 (SULT1C2) and carbohydrate (chondroitin 6) sulfotransferase 3 (CHST3). In addition, 11 SNPs in eight genes were associated with toxicities to treatment: spastic paraplegia 7 (pure and complicated autosomal recessive) (SPG7), CHST3, cytochrome P450, family 2, subfamily D, polypeptide 6 (CYP2D6), N-acetyltransferase 2 (arylamine N-acetyltransferase) (NAT2), ATP-binding cassette, sub-family C (CFTR/MRP), member 6 (ABCC6), ATPase, Cu + + transporting, alpha polypeptide (ATP7A), cytochrome P450, family 4, subfamily B, polypeptide 1 (CYP4B1) and solute carrier family 10 (sodium/bile acid cotransporter family), member 2 (SLC10A2). Genotyping results between drug metabolizing enzymes and transporters (DMET) and direct sequencing showed >96% of concordance. These findings highlight the role that non-CYP450 metabolizing enzymes and transporters may have in the pharmacology of docetaxel and thalidomide. The Pharmacogenomics Journal (2010) 10, 191-199; doi:10.1038/tpj.2009.57; published online 29 December 2009