Method of molecular docking in the design of new progesterone analogues

The aim of this study is to carry out the molecular docking of gestagenic preparations and structurally related compounds to the isoform A of human progesterone receptor and to assess the applicability of this method for the active progestins search. Docking was done (using Autodock 4.2) of progesterone and 13 compounds with different gestagenic/antigestagenic activity (megestrol acetate; (3)-3-Hydroxy-6-methyl-20-oxopregna-4,6-dien-17-yl acetate (AMOL); Medroxyprogesterone-17-acetate; Levonorgestrel; Dydrogesterone; RU-486; Ulipristal acetate; (3)-17-Acetoxy-6-methyl-20-oxopregna-4,6-dien-3-yl butyrate; 16,17-Cyclohexanoprogesterone; 6-Methyl-16,17-cyclohexanoprogesterone; Proligestone; 16,17-Cyclopentanoprogesterone; 16,17-Cyclohex-3-enoprogesterone). Calculations of theoretical dissociation constants (Kd) of ligand-progesterone receptor complexes showed that it is possible to evaluate the probability of activity of a candidate compound using the Autodock 4.2 program, but it requires caution, taking into account the lack of the link between Kd and gestagen activity. In addition, the method allows to identify compounds that change the position of amino acid residues in the ligand-binding domain of PR-A after binding (that is possibly have a different mechanism of action), as well as substances that do not interact with the agonistic form of the receptor due to other causes.

Prediction of Progestin Affinity for the Human Progesterone Receptor Based on Corrected RBA Data

The modeling of complexes of 3 sets of steroid and nonsteroidal progestins with the ligand-binding domain of the nuclear progesterone receptor was performed. Molecular docking procedure, long-term simulation of molecular dynamics and subsequent analysis by MM-PBSA (MM-GBSA) were used to model the complexes. Using the characteristics obtained by the MM-PBSA method two data sets of steroid compounds obtained in different scientific groups a prediction equation for the value of relative binding activity (RBA) was constructed. The RBA value was adjusted so that in all samples the actual activity was compared with the progesterone activity. The third data set of nonsteroidal compounds was used as a test. The resulted equation showed that the prediction results could be applied to both steroid molecules and nonsteroidal progestins.

KCNH1 potassium channels are expressed in cervical cytologies from pregnant patients and are regulated by progesterone

Potassium voltage-gated channel, subfamily H (eag-related), member 1 (KCNH1) potassium channels are potential tumour markers and cancer therapeutic targets and are up-regulated by oestrogens and human papilloma virus (HPV) oncogenes. However, the role of KCNH1 in normal tissues is poorly understood, and its expression in pregnancy is unknown. We wondered whether KCNH1 channels are expressed in cervical cells from pregnant patients and whether progesterone (P4) regulates KCNH1. The association with HPV was also investigated. KCNH1 protein expression was studied by immunocytochemistry in liquid-based cervical cytologies; 93 samples were obtained from pregnant patients at different trimesters, and 15 samples were obtained from non-pregnant women (controls). The presence ofHPVwas studied by PCR with direct sequencing and nested multiplex PCR. HeLa cervical cancer cells were transfected with human progesterone receptor-B (PR-B) and treated with P4.KCNH1mRNA expression in these cultures was studied by real-time PCR. KCNH1 protein was detected in 100% of the pregnancy samples and in 26% of the controls. We found 18 pregnant patients infected with HPV and detected 14 types ofHPV. There was no association between the percentage of cells expressing KCNH1 and either the presence or type of HPV. P4induced KCNH1 mRNA and protein expression in cells transfected with human PR-B. No regulation of KCNH1 by P4was observed in non-transfected cells. We show for the first time the expression of an ion channel during human pregnancy at different trimesters and KCNH1 regulation by P4in human cells. These data raise a new research field for KCNH1 channels in human tissues.