New imidazole-2-ones and their 2-thione analogues as anticancer agents and CAIX inhibitors: Synthesis, in silico ADME and molecular modeling studies

Column Chromatography-Free Synthesis of Spirooxindole and Spiroindanone-Based Naphthalimides as Potent c-MYC G4 Stabilizers and HSA Binders for Elevating Anticancer Potential

G-quadruplex (G4) DNA plays a pivotal regulatory role in fundamental biological processes, integral for governing cellular functions such as replication, transcription, and repair in living cells. Within cancer cells, G4 DNA exerts an impact on the expression of crucial genes such as c-MYC, effectively repressing its activity when structured within its promoter region. Therefore, employing molecular scaffolds to target these structures offers an attractive strategy for altering their functions. In our pursuit of potent and selective G-quadruplex binders, herein we report a series of spironaphthalimide-pyrrolidine analogues that demonstrate the ability to stabilize c-MYC G4 formation and subsequently inhibit c-MYC expression. These analogues are evaluated for their anticancer activity against 60 human cancer cell lines at 10 μM. The most potent analogues 8j and 21c underwent additional testing at five dose concentrations (10-4-10-8 M) where low MG-MID GI50 values are observed for both the analogues 8j (9.98 μM) and 21c (2.49 μM). To correlate with the antiproliferative activity, the mechanism is explored in vitro by performing Pu27 DNA binding studies through multispectroscopic techniques, and the results are compared with Pu22, human telomere, and calf thymus DNA. Additionally, insights from molecular docking suggested stacking over the G-tetrad of G4 structures of both analogues, with quantum mechanical studies further reinforcing the rationale for the stability of this quadruplex secondary structure. The analogues are also evaluated for their binding affinity to human serum albumin, revealing their robust capability to effectively bind and potentially facilitate targeted delivery to specific sites. Amidst the abundance of G4s across the human genome, the above findings underscore the significance of spiro analogues, with potent multitargeting anticancer attributes, marking a transformative leap forward in G4-ligand innovation, promising frontiers in the quest for effective anticancer modalities.

Design, Synthesis, Anticancer Screening, and Mechanistic Study of Spiro-N-(4-sulfamoyl-phenyl)-1,3,4-thiadiazole-2-carboxamide Derivatives

The present study aims to create spiro-N-(4-sulfamoyl-phenyl)-1,3,4-thiadiazole-2-carboxamide derivatives with anticancer activities. The in vitro anticancer evaluation showed that only the novel spiro-acenaphthylene tethered-[1,3,4]-thiadiazole (compound 1) exhibited significant anticancer efficacy as a selective inhibitor of tumor-associated isoforms of carbonic anhydrase. Compound 1 demonstrated considerable efficacy against the renal RXF393, colon HT29, and melanoma LOX IMVI cancer cell lines, with IC50 values of 7.01 ± 0.39, 24.3 ± 1.29, and 9.55 ± 0.51 µM, respectively. In comparison, doxorubicin exhibited IC50 values of 13.54 ± 0.82, 13.50 ± 0.71, and 6.08 ± 0.32 µM for the corresponding cell lines. Importantly, compound 1 exhibited lower toxicity to the normal WI 38 cell line than doxorubicin, with IC50 values of 46.20 ± 2.59 and 18.13 ± 0.93 µM, respectively, indicating greater selectivity of the target compound compared to the standard anticancer agent doxorubicin. Also, mechanistic experiments demonstrated that compound 1 exhibits inhibitory activity against human carbonic anhydrase hCA IX and XII, with IC50 values of 0.477 ± 0.03 and 1.933 ± 0.11 μM, respectively, indicating enhanced selectivity for cancer-associated isoforms over cytosolic isoforms hCA I and II, with IC50 values of 7.353 ± 0.36 and 12.560 ± 0.74 μM, respectively. Cell cycle studies revealed that compound 1 caused G1 phase arrest in RXF393 cells, and apoptosis experiments verified a substantial induction of apoptosis with significant levels of early and late apoptosis, as well as necrosis (11.69%, 19.78%, and 3.66%, respectively), comparable to those induced by the conventional cytotoxic agent doxorubicin, at 9.91%, 23.37%, and 6.16%, respectively. Molecular docking experiments confirmed the strong binding affinity of compound 1 to the active sites of hCA IX and XII, highlighting significant interactions with zinc-binding groups and hydrophobic residues. These findings underscore the target compound's potential as a viable anticancer agent via targeting CA.

Synthesis and effect of 4-acetylphenylamine-based imidazole derivatives on migration and growth of 3D cultures of breast, prostate and brain cancer cells

In this study, we have synthesized novel 4-acetophenone moiety-bearing functionalized imidazole derivatives containing S-, and N-ethyl substituents and evaluated their anticancer activity. Their anticancer activity was studied against human breast carcinoma (MDA-MB-231), human prostate carcinoma (PPC-1), and human glioblastoma (U-87). Compounds 4, 9, 14, and 22 were identified as the most promising anticancer agents from a series of imidazole derivatives. They showed the highest cytotoxicity by MTT assay against MDA-MB-231, PPC-1 and U-87 cell lines. Compounds 14 and 22 were most selective against PPC-1 and U-87 cell lines, and their EC50 values against these cell lines ranged from 3.1 to 47.2 µM. Most tested compounds showed lower activity against the triple-negative breast cancer MDA-MB-231 cell line. None of the imidazole derivatives possessed an inhibiting effect on the migration of PPC-1 and U-87 cells by 'wound' healing assay. In spheroid assay, the most promising were compounds 14 and 22, especially in PPC-1 3D cultures. They efficiently reduced both the size and the viability of PPC-1 spheroid cells.

Novel imidazolone derivatives as potential dual inhibitors of checkpoint kinases 1 and 2: Design, synthesis, cytotoxicity evaluation, and mechanistic insights

Applying various drug design strategies including ring variation, substituents variation, and ring fusion, two series of 2-(alkylthio)-5-(arylidene/heteroarylidene)imidazolones and imidazo[1,2-a]thieno[2,3-d]pyrimidines were designed and prepared as dual potential Chk1 and Chk2 inhibitors. The newly synthesized hybrids were screened in NCI 60 cell line panel where the most active derivatives 4b, d-f, and 6a were further estimated for their five dose antiproliferative activity against the most sensitive tumor cells including breast MCF-7 and MDA-MB-468 and non-small cell lung cancer EKVX as well as normal WI-38 cell. Noticeably, increasing the carbon chain attached to thiol moiety at C-2 of imidazolone scaffold elevated the cytotoxic activity. Hence, compounds 4e and 4f, containing S-butyl fragment, exhibited the most antiproliferative activity against the tested cells where 4f showed extremely potent selectivity toward them. As well, compound 6a, containing imidazothienopyrimidine core, exerted significant cytotoxic activity and selectivity toward the examined cells. The mechanistic investigation of the most active cytotoxic analogs was achieved through the evaluation of their inhibitory activity against Chk1 and Chk2. Results revealed that 4f displayed potent dual inhibition of both Chk1 and Chk2 with IC50 equal 0.137 and 0.25 μM, respectively. It also promoted its antiproliferative and Chk suppression activity via EKVX cell cycle arrest at S phase through stimulating the apoptotic approach. The apoptosis induction was also emphasized by elevating the expression of Caspase-3 and Bax, that are accompanied by Bcl-2 diminution. The in silico molecular docking and ADMET profiles of the most active analogs have been carried out to evaluate their potential as significant anticancer drug candidates.

In-silico design of novel potential HDAC inhibitors from indazole derivatives targeting breast cancer through QSAR, molecular docking and pharmacokinetics studies

Latest studies confirmed that abnormal function of histone deacetylase (HDAC) plays a pivotal role in formation of tumors and is a potential therapeutic target for treating breast cancer. In this research, in-silico drug discovery approaches via quantitative structure activity relationship (QSAR) and molecular docking simulations were adapted to 43 compounds of indazole derivatives with HDAC inhibition for anticancer activity against breast cancer. The QSAR models were built from multiple linear regression (MLR), and models predictability was cross-validated by leave-one-out (LOO) method. Based on these results, compounds C32, C26 and C31 from model 3 showed superior inhibitory activity with pIC50 of 9.30103, 9.1549 and 9.1549. We designed 10 novel compounds with molecular docking scores ranging from -7.9 to -9.3 kcal/mol. The molecular docking simulation results reveal that amino acid residues ILE1122 and PRO1123 play a significant role in bonding with 6CE6 protein. Furthermore, newly designed compounds P5, P2 and P7 with high docking scores of -9.3 kcal/mol, -8.9 kcal/mol and -8.8 kcal/mol than FDA-approved drug Raloxifene (-8.5 kcal/mol) and aid in establishment of potential drug candidate for HDAC inhibitors. The in-silico ADME functionality is used in the final phase to evaluate newly designed inhibitors as potential drug candidates. The results suggest that newly designed compounds P5, P2 and P7 can be used as a potential anti-breast cancer drug candidate.