The Anti-Proliferative Activity of the Hybrid TMS-TMF-4f Compound Against Human Cervical Cancer Involves Apoptosis Mediated by STAT3 Inactivation

Discovery of a stilbenoid-flavanone hybrid as an antitumor Wnt/β-catenin signaling pathway inhibitor

A series of designed stilbenoid-flavanone hybrids featuring sp3-hybridized C2 and C3 atoms of C-ring was evaluated against colorectal cancers presented compounds 4, 17, and 20 as the most potential compounds among explored compounds. Evaluation of the anticancer activity spectrum of compounds 4, 17, and 20 against diverse solid tumors presented compounds 17 and 20 with interesting anticancer spectrum. The potencies of compounds 17 and 20 were assessed in comparison with FDA-approved anticancer drugs. Compound 17 was the, in general, the most potent showing low micromolar GI50 values that were more potent than the standard FDA-approved drugs against several solid tumors including colon, brain, skin, renal, prostate and breast tumors. Compound 17 was subjected for evaluation against normal cell lines and was subjected to a mechanism study in HCT116 colon cancer cells which presented it as an inhibitor of Wnt signaling pathway triggering G2/M cell cycle arrest though activation of p53-p21 pathway as well as intrinsic and extrinsic apoptotic death of colon cancer cells. Compound 17 might be a candidate for further development against diverse solid tumors including colon cancer.

Repurposing Synthetic Congeners of a Natural Product Aurone Unveils a Lead Antitumor Agent Inhibiting Folded P-Loop Conformation of MET Receptor Tyrosine Kinase

A library of 24 congeners of the natural product sulfuretin were evaluated against nine panels representing nine cancer diseases. While sulfuretin elicited very weak activities at 10 µM concentration, congener 1t was identified as a potential compound triggering growth inhibition of diverse cell lines. Mechanistic studies in HCT116 colon cancer cells revealed that congener 1t dose-dependently increased levels of cleaved-caspases 8 and 9 and cleaved-PARP, while it concentration-dependently decreased levels of CDK4, CDK6, Cdc25A, and Cyclin D and E resulting in induction of cell cycle arrest and apoptosis in colon cancer HCT116 cells. Mechanistic study also presented MET receptor tyrosine kinase as the molecular target mediating the anticancer activity of compound 1t in HCT116 cells. In silico study predicted folded p-loop conformation as the form of MET receptor tyrosine kinase responsible for binding of compound 1t. Together, the current study presents compound 1t as an interesting anticancer lead for further development.

Design, synthesis, and evaluation of new anti-inflammatory natural products amide derivatives endowed with anti-blood cancer activity towards development of potential multifunctional agents against hematological cancers

New amide derivatives of the natural product 5,6,7-trimethoxyflavanone were designed as multifunctional antiproliferative molecules against blood cancer and the associated inflammatory conditions. The targeted compounds were synthesized efficiently in three linear steps employing known chalcone starting materials. Compounds 2h, 2i, 2l, 2t, 2v and 2x having bromo or nitro substituted-phenyl rings elicited potential inhibitory effects on macrophages production of nitric oxide, PGE₂ and TNF-α which are proinflammatory mediators involved in tumorigenesis and progression of blood cancer. Additionally, evaluation of direct inhibitory effects on the growth of diverse blood cancers including leukemia, lymphoma, and myeloma cell lines unveiled compound 2v as the most potential molecules eliciting at least five-folds the potency of the standard imatinib drug over the used diverse blood cancers. Furthermore, compound 2v showed good selectivity to blood cancer cells rather than normal MRC5 cells. Moreover, compound 2v triggered death of HL60 leukemia cells via apoptosis induction. In conclusion, the natural product-derived compound 2v might serve as a multifunctional lead compound for further development of agents for treatment of blood cancers.

Scaffold hopping of N-benzyl-3,4,5-trimethoxyaniline: 5,6,7-Trimethoxyflavan derivatives as novel potential anticancer agents modulating hippo signaling pathway

Scaffold hopping of N-benzyl-3,4,5-trimethoxyaniline afforded 5,6,7-trimethoxyflavan derivatives that were efficiently synthesized in four linear steps. As lung cancer is the most lethal cancer, twenty-three synthesized compounds were evaluated against a panel of lung cancer cells. Amongst, compounds 8q and 8e showed interesting activity. Hence, compounds 8q and 8e were evaluated against panels of diverse cancers. Compounds 8q and 8e showed broad spectrum anticancer activity. However, compound 8q was more effective and, hence, was advanced for potency evaluation and characterization. Compound 8q showed comparable potencies to gefitinib, and oxaliplatin against lung and colorectal cancers, respectively, and superior potencies to temozolomide, dacarbazine, cisplatin, enzalutamide, methotrexate, imatinib against brain, skin, ovary, prostate, breast, and blood cancers, respectively. Compound 8q increased cleaved PARP, caspase 3, and 7 inducing apoptosis. In addition, it inhibited cyclins A, B₁, H and cdc25c, and increased p53 triggering cell cycle arrest in G₂/M phase. Moreover, it decreased YAP and increased LATS1 and p-mob1/mob1 activating hippo signaling. Furthermore, it decreased p-PI3K/PI3k, p-mTOR/mTOR and p-P70S6K/P70S6K inhibiting PI3k pathway. Together, these findings present compound 8q as a potential anticancer lead compound for further development of potential agents.

Escaping ESKAPE resistance: in vitro and in silico studies of multifunctional carbamimidoyl-tethered indoles against antibiotic-resistant bacteria

Combining the hybridization and repurposing strategies, six compounds from our in-house library and having a designed hybrid structure of MBX-1162, pentamidine and MMV688271 were repurposed as potential antibacterial agents. Among, compounds 1a and 1d elicited potential sub-µg ml^-1 activity against the high-priority antibiotic-resistant Gram-positive members of ESKAPE bacteria as well as antibiotic-susceptible Gram-positive bacteria. Furthermore, they showed potential low µg ml^-1 activity against the explored critical-priority antibiotic-resistant Gram-negative members of ESKAPE bacteria. In time-kill assay, compound 1a has effective 0.5 and 0.25 µg ml^-1 antibacterial lethal concentrations against MRSA in exponential growth phase. In silico investigations predicted compounds 1a and 1d as inhibitors of the open conformation of undecaprenyl diphosphate synthase involved in bacterial isoprenoid synthesis. In addition, compounds 1a and 1d were predicted as inhibitors of NADPH-free but not NADPH-bound form of ketol-acid reductoisomerase and may also serve as potential B-DNA minor groove binders with possible differences in the molecular sequence recognition. Overall, compounds 1a and 1d are presented as multifunctional potential antibacterial agents for further development against high- and critical-priority Gram-positive and Gram-negative antibiotic-resistant ESKAPE bacterial pathogens as well as antibiotic-susceptible Gram-positive bacterial pathogens.

Bestatin analogs-4-quinolinone hybrids as antileishmanial hits: Design, repurposing rational, synthesis, in vitro and in silico studies

Amongst different forms of leishmaniasis, visceral leishmaniasis caused by L. donovani is highly mortal. Identification of new hit compounds might afford new starting points to develop novel therapeutics. In this lieu, a rationally designed small library of bestatin analogs-4-quinolone hybrids were prepared and evaluated. Analysis of SAR unveiled distinct profiles for hybrids type 1 and type 2, which might arise from their different molecular targets. Amongst type 1 bestatin analog-4-quinolone hybrids, hybrid 1e was identified as potential hit inhibiting growth of L. donovani promastigotes by 91 and 53% at 50 and 25 μM concentrations, respectively. Meanwhile, hybrid 2j was identified amongst type 2 bestatin analog-4-quinolone hybrids as potential hit compound inhibiting growth of L. donovani promastigotes by 50 and 38% at 50 and 25 μM concentrations, respectively. Preliminary safety evaluation of the promising hit compounds showed that they are 50-100 folds safer against human derived monocytic THP-1 cells relative to the drug erufosine. In silico study was conducted to predict the possible binding of hybrid 1e with methionine aminopeptidases 1 and 2 of L. donovani. Molecular dynamic simulations verified the predicted binding modes and provide more in depth understanding of the impact of hybrid 1e on LdMetAP-1 and LdMetAP-2.

AKF-D52, a Synthetic Phenoxypyrimidine-Urea Derivative, Triggers Extrinsic/Intrinsic Apoptosis and Cytoprotective Autophagy in Human Non-Small Cell Lung Cancer Cells

Simple Summary

We previously reported the antiproliferative effects of a phenoxypyridine urea derivative. In this study, we aimed to investigate the antiproliferative effects of 1-(3,5-dimethoxyphenyl)-3-(4-(3-methoxyphenoxy)-2-((4-morpholinophenyl)amino)pyrimidin-5-yl)urea (AKF-D52) in non-small cell lung cancer cells. We found that (i) AKF-D52 induces apoptosis in caspase-dependent and caspase-independent pathways; (ii) AKF-D52-induced apoptosis is caused by the clustering of a death-inducing signaling complex and mitochondrial-dependent signaling; (iii) AKF-D52 induces cytoprotective autophagy, and pre-treatment with an autophagy inhibitor enhances the apoptotic effect of AKF-D52; and (iv) AKF-D52-induced apoptosis and autophagy are attenuated by the reactive oxygen species (ROS) scavenger α-tocopherol. Furthermore, AKF-D52 suppressed tumor growth in a xenograft mouse model. Collectively, our findings regarding the efficacy and molecular mechanisms of AKF-D52 identify this compound as a potential therapeutic agent for the treatment of lung cancer.

Abstract

Previously, we discovered that 1-(3,5-dimethoxyphenyl)-3-(4-(3-methoxyphenoxy)-2-((4-morpholinophenyl)amino)pyrimidin-5-yl)urea (AKF-D52), a synthetic phenoxypyrimidine urea derivative, acts as a growth inhibitor of various cancer cell types. In this study, we elucidated the antiproliferative properties of AFK-D52 and underlying mechanisms in non-small cell lung cancer (NSCLC) cells and an A549 xenograft animal model. AKF-D52 was found to induce both caspase-dependent and -independent apoptotic cell death. Furthermore, the mitochondrial component of the AKF-D52-induced apoptosis mechanism involves a reduction in mitochondrial membrane potential and regulation in B cell lymphoma-2 family protein expression. Moreover, AKF-D52 activates the extrinsic pathway through up-regulated expression of death receptor 3 and Fas and then the formation of a death-inducing signaling complex. AKF-D52 also induced autophagy by increasing acidic vesicular organelle formation and microtubule-associated protein 1A/1B-light chain 3-II levels and reducing p62 levels. Notably, pretreatment with autophagy inhibitors enhanced AKF-D52-induced cell death, indicating that the induced autophagy is cytoprotective. AKF-D52 treatment also triggered reactive oxygen species (ROS) production in NSCLC cells, whereas the antioxidant α-tocopherol abolished AKF-D52-induced cell death. In a xenograft lung cancer mouse model, AKF-D52 administration attenuated tumor growth by inducing apoptosis and autophagy in tumor tissues. Collectively, our data indicate that AKF-D52-induced ROS production plays a role in mediating apoptosis and cytoprotective autophagy in NSCLC.

Regulation of ROS-Dependent JNK Pathway by 2'-Hydroxycinnamaldehyde Inducing Apoptosis in Human Promyelocytic HL-60 Leukemia Cells

The present study demonstrated that 2'-hydroxycinnamaldehyde (2'-HCA) induced apoptosis in human promyelocytic leukemia HL-60 cells through the activation of mitochondrial pathways including (1) translocation of Bim and Bax from the cytosol to mitochondria, (2) downregulation of Bcl-2 protein expression, (3) cytochrome c release into the cytosol, (4) loss of mitochondrial membrane potential (ΔΨ_m), and (5) caspase activation. 2'-HCA also induced the activation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase1/2 (ERK1/2) in HL-60 cells. The pharmacological and genetic inhibition of JNK effectively prevented 2'-HCA-induced apoptosis and activator protein-1 (AP-1)-DNA binding. In addition, 2'-HCA resulted in the accumulation of reactive oxygen species (ROS) and depletion of intracellular glutathione (GSH) and protein thiols (PSH) in HL-60 cells. NAC treatment abrogated 2'-HCA-induced JNK phosphorylation, AP-1-DNA binding, and Bim mitochondrial translocation, suggesting that oxidative stress may be required for 2'-HCA-induced intrinsic apoptosis. Xenograft mice inoculated with HL-60 leukemia cells demonstrated that the intraperitoneal administration of 2'-HCA inhibited tumor growth by increasing of TUNEL staining, the expression levels of nitrotyrosine and pro-apoptotic proteins, but reducing of PCNA protein expression. Taken together, our findings suggest that 2'-HCA induces apoptosis via the ROS-dependent JNK pathway and could be considered as a potential therapeutic agent for leukemia.

MiR-342 controls Mycobacterium tuberculosis susceptibility by modulating inflammation and cell death

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb) that places a heavy strain on public health. Host susceptibility to Mtb is modulated by macrophages, which regulate the balance between cell apoptosis and necrosis. However, the role of molecular switches that modulate apoptosis and necrosis during Mtb infection remains unclear. Here, we show that Mtb-susceptible mice and TB patients have relatively low miR-342-3p expression, while mice with miR-342-3p overexpression are more resistant to Mtb. We demonstrate that the miR-342-3p/SOCS6 axis regulates anti-Mtb immunity by increasing the production of inflammatory cytokines and chemokines. Most importantly, the miR-342-3p/SOCS6 axis participates in the switching between Mtb-induced apoptosis and necrosis through A20-mediated K48-linked ubiquitination and RIPK3 degradation. Our findings reveal several strategies by which the host innate immune system controls intracellular Mtb growth via the miRNA-mRNA network and pave the way for host-directed therapies targeting these pathways.

Effect of the dichloro-substitution on antiproliferative activity of phthalimide-thiazole derivatives. Rational design, synthesis, elastase, caspase 3/7, and EGFR tyrosine kinase activity and molecular modeling study

Phthalimide derivatives are a promising group of anticancer drugs, while aminothiazoles have great potential as elastase inhibitors. In these context fourteen phthalimido-thiazoles containing a dichloro-substituted phenyl ring with high antiproliferative activity against various cancer cell lines were designed and synthesized. Among the screened derivatives, compounds 5a-5e and 6a-6f showed high activity against human leukemia (MV4-11) cells with IC₅₀ values in the range of 5.56-16.10 µM. The phthalimide-thiazoles 5a, 5b and 5d showed the highest selectivity index (SI) relative to MV4-11 with 11.92, 10.80 and 8.21 values, respectively. The antiproliferative activity of compounds 5e, 5f and 6e, 6f against human lung carcinoma (A549) cells is also very high, with IC₅₀ values in the range of 6.69-10.41 µM. Lead compounds 6e and 6f showed elastase inhibition effect, with IC₅₀ values about 32 μM with mixed mechanism of action. The molecular modeling studies showed that the binding energies calculated for all set of compounds are strongly correlated with the experimentally determined values of IC₅₀. The lead compound 6e also increases almost 16 times caspase 3/7 activity in A549 cells compared to control. We have also demonstrated that compound 6f reduced EGFR tyrosine kinase levels in A549 cells by approximately 31%. These results clearly suggest that 3,4-dichloro-derivative 6e and 3,5-dichloro-derivative 6f could constitute lead dual-targeted anticancer drug candidates.

Design and synthesis of novel Flavone-based histone deacetylase inhibitors antagonizing activation of STAT3 in breast cancer

Histone deacetylases (HDACs) inhibitors have demonstrated a great clinical achievement in hematological malignancies. However, the efficacy of HDACs inhibitors in treating solid tumors remains limited due to the complicated tumor microenvironment. In this study, we designed and synthesized a class of novel HDACs inhibitors based on the structure of flavones and isoflavones, followed by biological evaluation. To be specific, a lead compound 15a was discovered with strong anti-proliferative effects on a variety of solid tumor cells, especially for breast cancer cells with resistance to SAHA. Studies demonstrated that 15a could significantly inhibit the activity of HDAC 1, 2, 3 (class I) and 6 (class IIB), leading to a dose-dependent accumulation of acetylated histones and α-Tubulin, cell cycle arrest (G1/S phase) and apoptosis in breast cancer cells. Furthermore, the lead compound 15a could also antagonize the activation of STAT3 induced by HDACs inhibition in some breast cancer cells, which further reduced the level of pro-survive proteins in tumor cells and enhanced anti-tumor activity regulated by STAT3 signaling in vivo. Overall, our findings demonstrated that the novel compound 15a might be a HDACs inhibitor candidate, which could be used as promising chemotherapeutic agent for breast cancer.

KCP10043F Represses the Proliferation of Human Non-Small Cell Lung Cancer Cells by Caspase-Mediated Apoptosis via STAT3 Inactivation

We previously reported that 4-(4-fluorobenzylcarbamoylmethyl)-3-(4-cyclohexylphenyl)-2-[3-(N,N-dimethylureido)-N'-methylpropylamino]-3,4-dihydroquinazoline (KCP10043F) can induce G₁-phase arrest and synergistic cell death in combination with etoposide in lung cancer cells. Here, we investigated the underlying mechanism by which KCP10043F induces cell death in non-small cell lung cancer (NSCLC). Propidium iodide (PI) and annexin V staining revealed that KCP10043F-induced cytotoxicity was caused by apoptosis. KCP10043F induced a series of intracellular events: (1) downregulation of Bcl-2 and Bcl-xL and upregulation of Bax and cleaved Bid; (2) loss of mitochondrial membrane potential; (3) increase of cytochrome c release; (4) cleavage of procaspase-8, procaspase-9, procaspase-3, and poly (ADP-ribose) polymerase (PARP). In addition, KCP10043F exhibited potent inhibitory effects on constitutive or interleukin-6 (IL-6)-induced signal transducer and activator of transcription (STAT3) phosphorylation and STAT3-regulated genes including survivin, Mcl-1, and cyclin D₁. Furthermore, STAT3 overexpression attenuated KCP10043F-induced apoptosis and the cleavage of caspase-9, caspase-3, and PARP. Docking analysis disclosed that KCP10043F could bind to a pocket in the SH2 domain of STAT3 and prevent STAT3 phosphorylation. The oral administration of KCP10043F decreased tumor growth in an A549 xenograft mouse model, as associated with the reduced phosphorylated STAT3, survivin, Mcl-1, and Bcl-2 expression and increased TUNEL staining and PARP cleavage in tumor tissues. Collectively, our data suggest that KCP10043F suppresses NSCLC cell growth through apoptosis induction via STAT3 inactivation.