The novel indomethacin derivative CZ-212-3 exerts antitumor effects on castration-resistant prostate cancer by degrading androgen receptor and its variants

Quantitative Structure-activity Relationship (QSAR) Modelling of Indomethacin Derivatives using Regression Analysis

BACKGROUND

Indomethacin is a non-steroidal anti-inflammatory drug (NSAID) used for medication to reduce fever, spondylitis, or shoulder pain. It mainly works by the inhibition of prostaglandins, the endogenous signaling molecules.

METHODS

Fifteen indomethacin derivatives have been analyzed in relation to their physicochemical and molecular properties. Two-dimensional (2D) structures of fifteen indomethacin derivatives were drawn using the ACD Lab Chem Sketch version. Most of the topological parameters, such as wiener index (W), mean wiener index (Wa), Balaban indices (J), Balaban centric index (BAC), and molecular connectivity (χ), were calculated by using E Dragon software. The most common molecular file formats accepted in EDragon software were SMILES notations created online by Babel software and 2D structures of various derivatives, which were converted into 3D optimized structures using online CORINA, provided by Molecular Networks GMBH. 3D structures of compounds were also drawn on Gauss View software for calculations of various density functional theory (DFT) based quantum chemical descriptors, such as total energy (TE), softness (S), hardness (η), chemical potential (μ), highest occupied molecular orbital energy (HOMO), and lowest unoccupied molecular orbital energy (LUMO). All species were fully optimized in the gas phase with a 6-31+G* basis set. The harmonic vibrational frequency calculations were used to confirm that the optimized structures were minima, as characterized by positive vibrational frequencies.

RESULTS

Combinations of various descriptors, such as D, ID, IOR, Log P, Mr, Mv, Mw, Pc, BAC, Pz, St, W, Wa, 0χ, 1χ, 2χ,3χ,4χ, 5χ, and Xeq have been found to be significant for modeling of activity. QSAR model no. 2: pIC50= -20.605 (±6.600) IOR - 0.747 (±0.454) I1 -5.083 (±3.478) Xeq + 51.647 optimized with empirical parameters with high statistical quality (R= 0.921, R2=0.848) was found to be the best model obtained.

CONCLUSION

The QSAR model obtained suggests that substituents with a lesser value of the index of refraction and less electronegative groups were favourable for the activity, whereas indomethacin derivatives with a CH2CH2NHCONH(CH2)3ONO2 group at R1 position were unfavourable for the activity. The results were critically discussed based on regression data and cross-validation techniques. Pogliani factor Q and the results of the LOO (leave-one-out) method confirmed the reliability and predictability of the proposed models that could be highly beneficial for the future designing of new analogues with higher potency.

A Comprehensive Overview of Small-Molecule Androgen Receptor Degraders: Recent Progress and Future Perspectives

Prostate cancer (PC), the second most prevalent malignancy in men worldwide, has been proven to depend on the aberrant activation of androgen receptor (AR) signaling. Long-term androgen deprivation for the treatment of PC inevitably leads to castration-resistant prostate cancer (CRPC) in which AR remains a crucial oncogenic driver. Thus, there is an urgent need to develop new strategies to address this unmet medical need. Targeting AR for degradation has recently been in a vigorous development stage, and accumulating clinical studies have highlighted the benefits of AR degraders in CRPC patients. Herein, we provide a comprehensive summary of small-molecule AR degraders with diverse mechanisms of action including proteolysis-targeting chimeras (PROTACs), selective AR degraders (SARDs), hydrophobic tags (HyT), and other AR degraders with distinct mechanisms. Accordingly, their structure-activity relationships, biomedical applications, and therapeutic values are also dissected to provide insights into the future development of promising AR degradation-based therapeutics for CRPC.

Crotonianoids A-C, Three Unusual Tigliane Diterpenoids from the Seeds of Croton tiglium and Their Anti-Prostate Cancer Activity

Crotonianoids A-C (1-3), three unusual tigliane diterpenoids, were isolated from the seeds of Croton tiglium. Compound 1 is a 13,14:13,15-diseco-tigliane featuring a unique spiro[bicyclo[5.3.0]decane-2,5'-2'(3'H,4'H)-furanone] core; 2 is a 13,15-seco-tigliane incorporating a rare peroxide bridge between C-13 and C-15; and 3 is the first example of a phorbol ester with a 10R-configuration. Their structures were determined by spectroscopic, computational, and X-ray diffraction methods. Compounds 1 and 2 markedly inhibited the growth and survival of prostate cancer cell C4-2B at micromolar concentrations and induced cell apoptosis. Mechanistic study revealed that 1 and 2 could suppress androgen receptor (AR) signaling pathway by promoting the degradation of AR protein.