RAD-140 (Testolone)

RAD-140 (Vosilasarm / Testolone) Research Standard

RAD-140, also indexed as vosilasarm and testolone (CAS 1182367-47-0), is a non-steroidal selective androgen receptor modulator (SARM) built on a benzonitrile / 1,3,4-oxadiazole scaffold rather than a steroid nucleus. It is supplied as a reference standard for laboratory work on androgen receptor (AR) pharmacology, tissue-selective nuclear receptor signalling, and analytical method development. Its value as a research tool is that it activates AR in a cell-context-dependent way, which makes it a workable probe for the question the SARM class exists to ask: how one receptor produces different transcriptional outputs in different tissues.^[1,2]

Mechanism of Action & Research Context

The molecular target is the androgen receptor (AR, NR3C4), a ligand-activated nuclear hormone receptor that functions as a transcription factor.

• Receptor binding and specificity. RAD-140 binds AR with high affinity, assayed against a panel of four nuclear receptors, and its downstream transcriptional output differs by cell type — activating AR in one carcinoma cell background while failing to do so in another. That divergence in a controlled in vitro comparison is the direct experimental basis for the word "selective" in the compound class name.^[2]

• Distinct genomic and non-genomic routes. Non-steroidal SARMs and the endogenous ligand DHT engage AR through different signalling arms and assemble different AR/cofactor complexes at androgen-responsive enhancers. The two ligand types are therefore not interchangeable in mechanistic experiments, which is the point of running both.^[4]

• Coregulator recruitment and dimerisation. In the wider class literature, a SARM can drive AR transcriptional activity while producing markedly less AR homodimerisation than DHT and recruiting only a restricted subset of cofactors — with p160 coactivators SRC1, TIF2 and NCoA3 notably absent in yeast two-hybrid interaction assays. Differential coregulator recruitment is the leading mechanistic account of tissue selectivity.^[5]

• MAPK/ERK signalling. In cultured rat hippocampal neurons, RAD-140 acts through AR with signalling dependent on the MAPK/ERK pathway: ERK phosphorylation increases, and the effect is blocked by the MEK inhibitor U0126. This gives a defined non-genomic readout in a non-reproductive tissue model.^[3]

Research Applications

Primary fields of in vitro and preclinical laboratory investigation include:

• AR binding and transactivation assays. Competitive ligand-binding measurements with nuclear-receptor counter-screens, paired with AR-driven reporter assays in transfected cell lines.^[1,2]

• Coregulator and dimerisation profiling. Yeast two-hybrid and peptide-interaction panels mapping which coactivators a given ligand does and does not recruit.^[4,5]

• Signalling pathway dissection. Phospho-ERK readouts with MEK inhibition to separate genomic from non-genomic AR signalling.^[3]

• Analytical and forensic method development. Reference material for chromatographic and mass-spectrometric identification, retention-time matching and metabolite characterisation, including liver-microsome incubations for phase I profiling.

Analytical Documentation

Purity and identity vary by manufacturing lot. Kimera Chems does not publish a single fixed purity figure for this item; refer to the batch-specific Certificate of Analysis (COA) issued for the lot received, which reflects third-party analytical testing for that lot.

References

1. Miller CP, Shomali M, Lyttle CR, et al. Design, synthesis, and preclinical characterization of the selective androgen receptor modulator (SARM) RAD140. ACS Med Chem Lett. 2011;2(2):124–129. doi:10.1021/ml1002508
2. Yu Z, He S, Wang D, et al. Selective androgen receptor modulator RAD140 inhibits the growth of androgen/estrogen receptor-positive breast cancer models with a distinct mechanism of action. Clin Cancer Res. 2017;23(24):7608–7620. doi:10.1158/1078-0432.CCR-17-0670
3. Jayaraman A, Christensen A, Moser VA, et al. Selective androgen receptor modulator RAD140 is neuroprotective in cultured neurons and kainate-lesioned male rats. Endocrinology. 2014;155(4):1398–1406. doi:10.1210/en.2013-1725
4. Narayanan R, Coss CC, Yepuru M, et al. Steroidal androgens and nonsteroidal, tissue-selective androgen receptor modulator, S-22, regulate androgen receptor function through distinct genomic and nongenomic signaling pathways. Mol Endocrinol. 2008;22(11):2448–2465. doi:10.1210/me.2008-0160
5. Furuya K, Yamamoto N, Ohyabu Y, et al. Mechanism of the tissue-specific action of the selective androgen receptor modulator S-101479. Biol Pharm Bull. 2013;36(3):442–451. doi:10.1248/bpb.b12-00885

Storage & Handling

Store at controlled room temperature. Keep tightly closed. Liquid formats: do not refrigerate or freeze. Cold storage may cause the solution to cloud or precipitate. If this occurs, return to room temperature and mix until clear.

Storage guidance is a house recommendation. Analytical documentation is per-lot release testing.

Related Research Compounds

• GSK-2881078
• LGD-2226
• OTR-AC
• MID-35

Research Use Only Disclaimer: This product is labeled and sold "For Research Use Only — NOT FOR HUMAN CONSUMPTION." It is not a drug, dietary supplement, food, cosmetic, or medical device, and it is not approved by the FDA or any other regulator for human or veterinary use. It is supplied to approved account holders as a research chemical for laboratory use and must be handled in accordance with applicable law.