Jorge A. Ascacio-Martínez

A pharmacogenetic pilot study reveals MTHFR, DRD3, and MDR1 polymorphisms as biomarker candidates for slow atorvastatin metabolizers

BackgroundThe genetic variation underlying atorvastatin (ATV) pharmacokinetics was evaluated in a Mexican population. Aims of this study were: 1) to reveal the frequency of 87 polymorphisms in 36 genes related to drug metabolism in healthy Mexican volunteers, 2) to evaluate the impact of these polymorphisms on ATV pharmacokinetics, 3) to classify the ATV metabolic phenotypes of healthy volunteers, and 4) to investigate a possible association between genotypes and metabolizer phenotypes.MethodsA pharmacokinetic study of ATV (single 80-mg dose) was conducted in 60 healthy male volunteers. ATV plasma concentrations were measured by high-performance liquid chromatography mass spectrometry. Pharmacokinetic parameters were calculated by the non-compartmental method. The polymorphisms were determined with the PHARMAchip® microarray and the TaqMan® probes genotyping assay.ResultsThree metabolic phenotypes were found in our population: slow, normal, and rapid. Six gene polymorphisms were found to have a significant effect on ATV pharmacokinetics: MTHFR (rs1801133), DRD3 (rs6280), GSTM3 (rs1799735), TNFα (rs1800629), MDR1 (rs1045642), and SLCO1B1 (rs4149056). The combination of MTHFR, DRD3 and MDR1 polymorphisms associated with a slow ATV metabolizer phenotype.ConclusionFurther studies using a genetic preselection method and a larger population are needed to confirm these polymorphisms as predictive biomarkers for ATV slow metabolizers.Trial registrationAustralian New Zealand Clinical Trials Registry: ACTRN12614000851662, date registered: August 8, 2014.

Production of Recombinant Human Placental Variant Growth Hormone in Pichia Pastoris

AbstractcDNA encoding mature human placental variant growth hormone (HGH-V) was synthesized by retro-transcription polymerase chain reaction (RT-PCR) from total RNA recovered from human term-placenta and cloned in pBluescript plasmid (pBS) in Escherichia coli. cDNA was subcloned into pPIC9, fusing it to the flanking regulatory sequences of the Pichia pastoris alcohol oxidase 1 gene (AOX1) and finally introduced into the genome of this yeast by homologous recombination. The resulting new recombinant strain produced and secreted, towards the culture medium, mature HGH-V, whose activity was demonstrated in cell culture by the Nb2 proliferation assay.