(02-10-2014, 03:48 AM)Lotus Wrote: Sorry people, I have to share this rather unique way to box out DHT, I stumbled across it when I was collecting some research, please follow along (my apologies for the technical crap explanation) I'll try to keep it in the ball park.
The problem with DHT is when it enters into receptors it locks it up, and thereby making Aromatase an after thought, Aromatase is enzyme that converts free T to estrogen. (Aka boob growth), here I suggest a novel (well, at least for BN) called "Androgen Decoy's".
http://www.ncbi.nlm.nih.gov/core/lw/2.0/html/tileshop_pmc/tileshop_pmc_inline.html?title=Click%20on%20image%20to%20zoom&p=PMC3&id=3132148_nihms255516f1.jpg
A transcriptional factor decoy strategy is the use of short double-stranded oligodeoxynucleotides containing a high-affinity binding site for specific transcription factors as a decoy DNA to be transfected into target cells [12–16]. Inside the cells, the decoy DNA competes with the endogenous high-affinity binding site of the target genes for binding to specific transcription factors, and consequently inhibits activated AR function [16]. Decoy DNA has potential for treatment of cardiovascular disease [12]. It also induces apoptosis in certain cell lines [13].
Androgen receptor decoy molecules block the growth of prostate cancer
http://www.pnas.org/content/104/4/1331.abstract
Androgen receptor: structure, role in prostate cancer and drug discovery
Androgens and androgen receptors (AR) play a pivotal role in expression of the male phenotype. Several diseases, such as androgen insensitivity syndrome (AIS) and prostate cancer, are associated with alterations in AR functions. Indeed, androgen blockade by drugs that prevent the production of androgens and/or block the action of the AR inhibits prostate cancer growth. However, resistance to these drugs often occurs after 2–3 years as the patients develop castration-resistant prostate cancer (CRPC). In CRPC, a functional AR remains a key regulator. Early studies focused on the functional domains of the AR and its crucial role in the pathology. The elucidation of the structures of the AR DNA binding domain (DBD) and ligand binding domain (LBD) provides a new framework for understanding the functions of this receptor and leads to the development of rational drug design for the treatment of prostate cancer. An overview of androgen receptor structure and activity, its actions in prostate cancer, and how structural information and high-throughput screening have been or can be used for drug discovery are provided herei
http://www.nature.com/aps/journal/vaop/n....html#fig1
The mechanism of action of testosterone.
Testosterone enters the cell by passive diffusion and is converted to DHT and estradiol. Testosterone and DHT bind to the androgen receptor located in the cytoplasm attached to heat-shock proteins (not shown). Upon binding of testosterone and DHT to androgen receptor, heat-shock protein is released and the receptor dimerizes. Estradiol binds to the estrogen receptors ERα, ERβ
Androgen and AR action. Genome organization of the human androgen receptor gene and the functional domain structure of the androgen receptor protein. (A) Androgen and AR signaling in prostate cells. After testicular synthesis, testosterone is transported to target tissues such as the prostate and becomes converted to dihydrotestosterone (DHT) by 5-α-reductase. DHT binds to the ligand-binding pocket and promotes the dissociation of heat-shock proteins (HSPs) from the AR. The AR then translocates into the nucleus, dimerizes and binds to the androgen response element (ARE) in the promoter region of target genes such as prostate-specific antigen (PSA) and TMPRSS2. At the promoter, the AR is able to recruit members of the basal transcription machinery [such as TATA-box-binding protein (TBP) and transcription factor IIF (TFIIF)] in addition to other coregulators such as members of the p160 family of coactivators and cAMP-response element-binding protein (CREB)-binding protein (CBP). SHBG: serum sex hormone-binding globulin. (B) The androgen receptor gene has been mapped to the long arm of the X-chromosome (locus: Xq11-q12). It contains eight exons interrupted by introns of varying lengths (0.7–2.6 kb) and codes for a protein of 919 amino acids consisting of several functional domains (N-terminal domain (NTD), DNA binding domain (DBD) and ligand binding domain (LBD); amino acid residue numbers are indicated above the AR protein domain map). Exon 1 codes for the NTD, exons 2 and 3 encode the DBD, and exons 4 to 8 encode both the hinge and LBD.
Comparison of crystal structures of human androgen receptor ligand-binding domain complexed with various agonists reveals molecular determinants responsible for binding affinity.
Abstract
Androgens exert their effects by binding to the highly specific androgen receptor (AR). In addition to natural potent androgens, AR binds a variety of synthetic agonist or antagonist molecules with different affinities. To identify molecular determinants responsible for this selectivity, we have determined the crystal structure of the human androgen receptor ligand-binding domain (hARLBD) in complex with two natural androgens, testosterone (Testo) and dihydrotestosterone (DHT), and with an androgenic steroid used in sport doping, tetrahydrogestrinone (THG), at 1.64, 1.90, and 1.75 A resolution, respectively. Comparison of these structures first highlights the flexibility of several residues buried in the ligand-binding pocket that can accommodate a variety of ligand structures. As expected, the ligand structure itself (dimension, presence, and position of unsaturated bonds that influence the geometry of the steroidal nucleus or the electronic properties of the neighboring atoms, etc.) determines the number of interactions it can make with the hARLBD. Indeed, THG--which possesses the highest affinity--establishes more van der Waals contacts with the receptor than the other steroids, whereas the geometry of the atoms forming electrostatic interactions at both extremities of the steroid nucleus seems mainly responsible for the higher affinity measured experimentally for DHT over Testo. Moreover, estimation of the ligand-receptor interaction energy through modeling confirms that even minor modifications in ligand structure have a great impact on the strength of these interactions. Our crystallographic data combined with those obtained by modeling will be helpful in the design of novel molecules with stronger affinity for the AR.
http://www.ncbi.nlm.nih.gov/pubmed/16641486?dopt=Abstract&holding=npg
stupid auto correct!
