Novel spiroindoline quinazolinedione derivatives as anticancer agents and potential FLT3 kinase inhibitors

Combination of chemotherapy and c-MET inhibitors has synergistic effects in c-MET overexpressing pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) remains as one of the most lethal malignancies. c-MET is an important oncogenic kinase involved in PDAC progression. We determined the anticancer effect of c-MET inhibitors, crizotinib and cabozantinib, combined with chemotherapeutic agents, doxorubicin, oxaliplatin and gemcitabine, against different PDAC and a lung adenocarcinoma cell line expressing different levels of c-MET. MTT assay was performed to assess cell growth inhibition. Synergistic combinations were evaluated in spheroid cultures, while apoptosis was determined through Hoechst33258 staining. The effect of drug combinations on cell cycle and apoptosis induction was examined by RNase/PI flow cytometric assay. We also evaluated reactive oxygen species (ROS) levels using 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assay to explore the possible mechanisms contributing to synergism. Combination of crizotinib or cabozantinib with doxorubicin exhibited synergistic effects in c-MET overexpressing cells. Conversely, combinations of c-MET inhibitors with other agents were additive or even antagonistic. Combination index (CI) values calculated with Calcusyn software were 0.631-0.730 for crizotinib and 0.542-0.746 for cabozantinib co-administered with doxorubicin. These synergistic combinations showed significant spheroid growth inhibition and apoptosis induction in Suit-2, c-MET dependent PDAC cells. These combinations also significantly increased the number of cells in both apoptotic sub-G1 phase and the G2/M phase compared to single-drug treatment. Increased ROS production seemed to be a possible mechanism underlying synergism. In conclusion, c-MET inhibitors synergize with DNA damaging agent, doxorubicin, in cancer cells with c-MET overexpression, indicating that these combination therapies may be a promising cancer therapeutic strategy.

Development of indole hybrids for potential lung cancer treatment-part I: nitrogen-containing six-membered aromatic heterocycles

Lung cancer is the most prevalent invasive malignancy and the leading cause of cancer-related death. Chemotherapy is vital for lung cancer therapy, but multidrug resistance is responsible for the majority of lung cancer fatalities, creating an imperative demand to develop novel chemotherapeutics. Indole is a valuable anti-lung cancer pharmacophore since its derivatives could act on lung cancer cells through various mechanisms. Notably, indole hybrids could inhibit multiple targets simultaneously and have the potential to overcome the shortcomings of traditional chemotherapeutics. Moreover, many indole hybrids such as the indole-pyrimidine hybrid osimertinib and the indole-hydroxamic acid hybrid panobinostat, are either under clinical evaluations or have already been approved for lung cancer therapy. This indicates that the rational design of indole hybrids represents a highly prospective approach for the development of new anti-lung cancer chemotherapeutic agents. This review focuses on exploring the anti-lung cancer therapeutic potential of indole hybrids and delves into their action mechanisms as well as structure-activity correlations, covering articles published between 2021 and present. The ultimate goal is to offer a foundation for the rational design of indole hybrids in the future.

Spiroindoline quinazolinedione derivatives as inhibitors of P-glycoprotein: potential agents for overcoming multidrug resistance in cancer therapy

Multidrug resistance (MDR) presents a major challenge for effectiveness of chemotherapy. This study investigates the effectiveness of spiroindoline quinazolinediones in reversing MDR mediated by P-glycoprotein (P-gp) overexpression in cancer cells. A series of synthesized hybrid spiro[indoline-3,2'-quinazoline]-2,4'(3'H)-dione derivatives (compounds 5a-5l) were analyzed for their ability to enhance rhodamine 123 (Rhd123) accumulation in the MES-SA/DX5 cell line using flow cytometry. The MTT assay was also employed to evaluate the compounds' effectiveness in reversing drug resistance. Additionally, docking studies and molecular dynamics simulations were conducted to investigate the interaction of these compounds with the P-gp transporter. The Rhd123 accumulation assay in MDR cancer cells revealed that most compounds, in particular 5f, 5g, 5h, 5i, 5j, 5k, and 5l, exhibited significant potential as P-gp inhibitors. Among the tested derivatives, compounds 5g and 5l demonstrated the best effects, and increased Rhd123 accumulation up to 12.9 times compared to untreated cells. Additionally, compounds 5f through 5 l bearing methylbenzyl (5f), benzyl (5g), pentyl (5 ), p-bromobenzyl (5i), p-chlorobenzyl (5j), dichlorobenzyl (5k), and tert-butylbenzyl (5l) substituents on the isatin ring effectively restored sensitivity to doxorubicin at their non-toxic concentrations in resistant MES-SA/DX5 cells. Among these, compound 5l at 5 μM exhibited the highest inhibitory potential, and lowered doxorubicin's IC50 value 10.1 times compared to control. Moreover, in silico investigation identified the potential interactions of test compounds with critical residues of P-gp involved in its efflux function. Our study suggests that the synthesized spiroindoline quinazolinediones may have high potentials as agents capable of reversing MDR in cancer cells.

Design, synthesis and pharmacological evaluation of 1,4-naphthoquinone- 1,2,3-triazole hybrids as new anticancer agents with multi-kinase inhibitory activity

Targeting important oncogenic kinases that contribute to hallmarks of cancer has revolutionized cancer therapy. Ten 1,4-naphthoquinone derivatives linked to 1,2,3-triazole (4a-4j) were designed and synthesized as kinase inhibitors especially aimed at blocking CDK2, a validated and important cancer target. Assessment of the antiproliferative activity of the synthesized compounds against lung (EBC-1), pancreatic ductal adenocarcinoma (PDAC, AsPC-1 and Mia-Paca-2), colorectal (HT-29), and breast cancer (MCF-7) cells revealed that most of the derivatives possess considerable antiproliferative potential, with IC50 values as low as 0.3 µM. In contrast, the compounds relatively spared NIH3T3 non-cancer cell line. The kinase inhibitory effect of the best compounds was examined against a panel of 30 important oncogenic kinases. Derivatives 4a (bearing a benzyl ring) and 4i (bearing a p-methyl benzyl ring) inhibited CDK2, FLT4 (VEGFR3) and PDGFRA kinases with IC50 values in the range of 0.55-1.67 and 0.22-11.32 µM, respectively. These compounds also caused S phase arrest and induced characteristic features of apoptosis in PDAC cells. Molecular modeling simulation validated the binding interactions between the synthesized derivatives and the active sites of the 3 target kinases. Finally, the compounds also possessed drug-like features as examined by in silico studies. The results of this study indicate that 1,4-naphthoquinone derivatives could have promising anticancer potential as multi-kinase inhibitors.

Synthesis of C-N or C-C Spiroindolines via Rearrangement Coupling Reaction

Herein, we report a general approach to effectively construct C-N or C-C spiroindolines using tetrahydro-β-carbolines as starting materials via a rearrangement coupling reaction. This method is characterized by its operational simplicity and mild conditions. Notably, a wide range of anilines and indoles are suitable for this intermolecular coupling, yielding the corresponding C-N or C-C spiroindolines in good to excellent yields.

Expeditious Synthesis of Spiroindoline Derivatives via Tandem C(sp2)-H and C(sp3)-H Bond Functionalization of N-Methyl-N-nitrosoanilines

Presented herein is a novel synthesis of pharmaceutically privileged spiroindoline derivatives via cascade reactions of N-methyl-N-nitrosoanilines with diazo homophthalimides. A group of mechanistic studies disclosed that the formation of product involves an unusual reaction mode of N-methyl-N-nitrosoaniline featuring an initial C(sp2)-H bond activation/alkylation followed by a C(sp3)-H bond activation/spiroannulation. To our knowledge, this is the first example in which N-methyl-N-nitrosoaniline acts as a C3N1 synthon to accomplish formal [4+1] spiroannulation with the participation of the N-methyl unit rather than the previously reported C2N1 synthon to undergo formal [3+2] annulation without the participation of the N-methyl unit. In general, this newly developed synthetic protocol features simple and readily accessible starting materials, valuable products, unique reaction mechanism, high efficiency and atom-economy, excellent compatibility with diverse functional groups, and ready scalability.

Design, synthesis and antitumor activity of 2-substituted quinazoline-4-amine derivatives

Werner (WRN) syndrome protein is a multifunctional enzyme with helicase, ATPase, and exonuclease activities that are necessary for numerous DNA-related transactions in the human cell. Recent studies identified WRN as a synthetic lethal target in cancers. In this study, a series of new N-arylquinazoline-4-amine analogs were designed and synthesized based on structure optimization of quinazoline. The structures of the thirty-two newly synthesized compounds were confirmed by 1H NMR, 13C NMR and ESI-MS. The anticancer activity in vitro against chronic myeloid leukemia cells (K562), non-small cell lung cancer cells (A549), human prostate cancer cells (PC3), and cervical cancer cells (HeLa) of the target compounds was evaluated. Among them, the inhibition ratio of compounds 17d, 18a, 18b, 11 and 23a against four cancer cells at 5 μM concentration were more than 50 %. The IC50 values of compounds 18a and 18b were 0.3 ± 0.01 μM and 0.05 ± 0.02 μM in K562 cells respectively, compared with HeLa and A549 cells, 18a and 18b were more sensitive to K562 cells. In addition, the PC3 cells with WRN overexpression (PC3-WRN) was constructed, 18a and 18b and 23a were more sensitive to PC3-WRN cells compared with the control group cells (PC3-NC). Then, the cell viability of the novel WRN inhibitors were further assessed by colony formation assay. Compared with PC3-NC cells, 18b and 23a had obvious inhibitory effect on PC3-WRN cell at 1000 nM. In summary, these results indicated that the compounds 18b and 23a could be WRN protein inhibitor with potent anticancer properties in vitro.