A benzimidazole derivative exhibiting antitumor activity blocks EGFR and HER2 activity and upregulates DR5 in breast cancer cells

Albendazole inhibits colon cancer progression and therapy resistance by targeting ubiquitin ligase RNF20

BACKGROUND

The repurposing of FDA-approved drugs for anti-cancer therapies is appealing due to their established safety profiles and pharmacokinetic properties and can be quickly moved into clinical trials. Cancer progression and resistance to conventional chemotherapy remain the key hurdles in improving the clinical management of colon cancer patients and associated mortality.

METHODS

High-throughput screening (HTS) was performed using an annotated library of 1,600 FDA-approved drugs to identify drugs with strong anti-CRC properties. The candidate drug exhibiting most promising inhibitory effects in in-vitro studies was tested for its efficacy using in-vivo models of CRC progression and chemoresistance and patient derived organoids (PTDOs).

RESULTS

Albendazole, an anti-helminth drug, demonstrated the strongest inhibitory effects on the tumorigenic potentials of CRC cells, xenograft tumor growth and organoids from mice. Also, albendazole sensitized the chemoresistant CRC cells to 5-fluorouracil (5-FU) and oxaliplatin suggesting potential to treat chemoresistant CRC. Mechanistically, Albendazole treatment modulated the expression of RNF20, to promote apoptosis in CRC cells by delaying the G2/M phase and suppressing anti-apoptotic-Bcl2 family transcription.

CONCLUSIONS

Albendazole, an FDA approved drug, carries strong therapeutic potential to treat colon cancers which are aggressive and potentially resistant to conventional chemotherapeutic agents. Our findings also lay the groundwork for further clinical testing.

Synthesis, Anticancer Activity, and In Silico Modeling of Alkylsulfonyl Benzimidazole Derivatives: Unveiling Potent Bcl-2 Inhibitors for Breast Cancer

A series of alkylsulfonyl 1H-benzo[d]imidazole derivatives were synthesized and evaluated for anticancer activity against human breast cancer cells, MCF-7 in vitro. The cytotoxic potential was determined using the xCELLigence real-time cell analysis, and expression levels of genes related to microtubule organization, tumor suppression, apoptosis, cell cycle, and proliferation were examined by quantitative real-time polymerase chain reaction. Molecular docking against Bcl-2 was carried out using AutoDock Vina, while ADME studies were performed to predict the physicochemical and drug-likeness properties of the synthesized compounds. The results revealed that compounds 23 and 27 were the most potent cytotoxic derivatives against MCF-7 cells. Gene expression analysis showed that BCL-2 was the most prominent gene studied. Treatment of MCF-7 cells with compounds 23 and 27 resulted in significant downregulation of the BCL-2 gene, with fold changes of 128 and 256, respectively. Docking analysis predicted a strong interaction between the compounds and the target protein. Interestingly, all of the compounds exhibit a higher binding affinity toward Bcl-2 than the standard drug (compound 27 vina score = -9.6 kcal/mol, vincristine = -6.7 kcal/mol). Molecular dynamics simulations of compounds 23 and 27 showed a permanent stabilization in the binding site of Bcl-2 for 200 ns. Based on Lipinski and Veber's filters, all synthesized compounds displayed drug-like characteristics. These findings suggest that compounds 23 and 27 were the most promising cytotoxic compounds and downregulated the expression of the BCL-2 gene. These derivatives could be further explored as potential candidates for the treatment of breast cancer.

Mechanochemistry Frees Thiourea Dioxide (TDO) from the 'Veils' of Solvent, Exposing All Its Reactivity

The synthesis of nitrogen-based heterocycles has always been considered essential in developing pharmaceuticals in medicine and agriculture. This explains why various synthetic approaches have been proposed in recent decades. However performing as methods, they often imply harsh conditions or the employment of toxic solvents and dangerous reagents. Mechanochemistry is undoubtedly one of the most promising technologies currently used for reducing any possible environmental impact, addressing the worldwide interest in counteracting environmental pollution. Following this line, we propose a new mechanochemical protocol for synthesizing various heterocyclic classes by exploiting thiourea dioxide (TDO)'s reducing proprieties and electrophilic nature. Simultaneously exploiting the low cost of a component of the textile industry such as TDO and all the advantages brought by a green technique such as mechanochemistry, we plot a route towards a more sustainable and eco-friendly methodology for preparing heterocyclic moieties.

Novel 1,2,5-Trisubstituted Benzimidazoles Potentiate Apoptosis by Mitochondrial Dysfunction in Panel of Cancer Cells

Synthetic small molecules have been very effective in decimating cancer cells by targeting various aberrantly overexpressed oncogenic proteins. These small molecules target proteins involved in cell cycle regulation, cell division, migration, invasion, angiogenesis, and other regulatory proteins to induce apoptosis in cancer cells. In this study, we have synthesized a novel 1,2,5-trisubstituted benzimidazole chemical library of small molecules and unveiled their anticancer potential against a panel of cancer cell lines such as Jurkat, K-562, MOLT-4, HeLa, HCT116, and MIA PaCa-2 cancer cells. The MTT assay and Trypan blue dye exclusion assay clearly unveiled the cytotoxic effect of methyl 1-benzyl-2-(4-fluoro-3-nitrophenyl)-1H-benzo[d]imidazole-5-carboxylate (TJ08) and its potential to induce apoptosis with effective IC₅₀ of 1.88 ± 0.51, 1.89 ± 0.55, 2.05 ± 0.72, 2.11 ± 0.62, 3.04 ± 0.8, and 3.82 ± 0.25 μM against Jurkat, K562, MOLT-4, HeLa, HCT116, and MIA PaCa-2 cancer cell lines, respectively. Altered mitochondrial membrane potential was observed in HeLa, HCT116, and Jurkat cells due to TJ08 treatment, which was unveiled by JC10 staining. Induction of early and late apoptosis by TJ08 treatment was also unveiled by apoptotic analysis and immunofluorescence imaging. Cell cycle analysis distribution confirms the accumulation of cells in the S-phase in a dose-dependent manner.

Insights into the structure and drug design of benzimidazole derivatives targeting the epidermal growth factor receptor (EGFR)

Tyrosine kinase overexpression could result in an unfavourable consequence of cancer progression in the body. A number of kinase inhibitor drugs targeting various cancer-related protein kinases have been developed and proven successful in clinical therapy. Benzimidazole is one of the most studied scaffolds in the search for effective anticancer drugs. The association of various functional groups and the structural design of the compounds may influence the binding towards the receptor. Despite numerous publications on the design, synthesis and biological assays of benzimidazole derivatives, their inhibitory activities against epidermal growth factor receptor (EGFR), a receptor tyrosine kinase (RTK), have not been specifically analysed. This review covers recent research reports on the anticancer activity of benzimidazole derivatives focusing on EGFR expression cell lines, based on their structure-activity relationship study. We believe it would aid researchers to envision the challenges and explore benzimidazole's potentials as tyrosine kinase inhibitors.

Benzimidazole-Based Protein Kinase Inhibitors: Current Perspectives in Targeted Cancer Therapy

Targeted therapy has emerged to be the cornerstone of advanced cancer treatment, allowing for more selectivity and avoiding the common drug toxicity and resistance. Identification of potential targets having vital role in growth and survival of cancer cells got much easier with the aid of the recent advances in high throughput screening approaches. Various protein kinases came into focus as valuable targets in cancer therapy. Meanwhile, benzimidazole-based scaffolds have gained significant attention as promising protein kinase inhibitors with high potency and varied selectivity. Great diversity of these scaffolds has inspired the medicinal chemists to inspect the effect of structural changes upon inhibitory activity on the molecular level through modeling studies. The present review gathers all the considerable attempts to develop benzimidazole-based compounds; designed as protein kinase inhibitors with anticancer activity since 2015; that target aurora kinase, CDK, CK2, EGFR, FGFR, and VEGFR-2; to allow further development and progression regarding benzimidazoles.

Anti-Angiogenetic and Anti-Lymphangiogenic Effects of a Novel 2-Aminobenzimidazole Derivative, MFB

Background and Purpose

Benzimidazoles have attracted much attention over the last few decades due to their broad-spectrum pharmacological properties. Increasing evidence is showing the potential use of benzimidazoles as anti-angiogenic agents, although the mechanisms that impact angiogenesis remain to be fully defined. In this study, we aim to investigate the anti-angiogenic mechanisms of MFB, a novel 2-aminobenzimidazole derivative, to develop a novel angiogenesis inhibitor.

Experimental Approach

MTT, BrdU, migration and invasion assays, and immunoblotting were employed to examine MFB’s effects on vascular endothelial growth factor (VEGF)-induced endothelial cell proliferation, migration, invasion, as well as signaling molecules activation. The anti-angiogenic effects of MFB were analyzed by tube formation, aorta ring sprouting, and matrigel plug assays. We also used a mouse model of lung metastasis to determine the MFB’s anti-metastatic effects.

Key Results

MFB suppressed cell proliferation, migration, invasion, and endothelial tube formation of VEGF-A-stimulated human umbilical vascular endothelial cells (HUVECs) or VEGF-C-stimulated lymphatic endothelial cells (LECs). MFB suppressed VEGF-A and VEGF-C signaling in HUVECs or LECs. In addition, MFB reduced VEGF-A- or tumor cells-induced neovascularization in vivo. MFB also diminished B16F10 melanoma lung metastasis. The molecular docking results further showed that MFB may bind to VEGFR-2 rather than VEGF-A with high affinity.

Conclusions and Implications

These observations indicated that MFB may target VEGF/VEGFR signaling to suppress angiogenesis and lymphangiogenesis. It also supports the role of MFB as a potential lead in developing novel agents for the treatment of angiogenesis- or lymphangiogenesis-associated diseases and cancer.

Deep exploration of immune function in EGFR wild-type and mutated lung adenocarcinomas by gene expression profiling: role of TRAIL-R2 (TNFRSF10B) in patient treatment and outcome

The tumor microenvironment is important in the initiation and progression of lung adenocarcinoma (LUAD). In this study, we aim to analyze the expression profile of immune-related genes in LUADs, examine the differential expression of immune-related genes in epidermal growth factor receptor (EGFR) wild-type and mutant LUADs, and the clinicopathologic significance of these differentially expressed genes. We used the NanoString PanCancer Immune Profiling Panel to examine 34 cases of LUADs (18 EGFR wild-type, 16 EGFR mutant). In EGFR wild-type LUADs, the macrophage and neutrophil signatures are significantly higher, and significantly higher expression of chemokines, interleukins, leukocyte, macrophage, natural killer cell, pathogen defense, Tumor necrosis factor superfamily, and transporter function signatures are also observed. TNFRSF10B mRNA was preferentially expressed in EGFR wild-type LUADs (p = 6.15e-6^, adjusted p = 0.0244). Immunohistochemical staining for TRAIL-R2 (encoded by TNFRSF10B) on 134 tissue microarray LUAD cases demonstrated strong, moderate, and weak staining in 75 (56.0%), 46 (34.3%), and 13 (9.7%) cases, respectively. Strong TRAIL-R2 expression was significantly associated with poor overall survival (OS) in all stages and EGFR wild-type LUADs, but not in EGFR-mutant tumors. Furthermore, strong TRAIL-R2 expression (p = 0.004) was an independent risk factor for poor OS. In summary, TNFRSF10B mRNA revealed significantly higher expression in EGFR wild-type LUADs, and strong TRAIL-R2 expression predicts an unfavorable prognosis for these tumors. These patients may benefit from additional treatment with TRAIL-R2 targeted therapies.

Benzimidazoles Against Certain Breast Cancer Drug Targets: A Review

BACKGROUND

Benzimidazoles are widely used scaffolds against various types of cancer including breast cancer. To this end, anticancer agents must be developed using the knowledge of the specific targets of BC.

OBJECTIVE

In this study, we aim to review the compounds used against some of the biomolecular targets of breast cancer. To this end, we present information about the various targets, with their latest innovative studies.

CONCLUSION

Benzimidazole ring is an important building block that can target diverse cancer scenarios since it can structurally mimic biomolecules in the human body. Additionally, many studies imply the involvement of this moiety on a plethora of pathways and enzymes related to BC. Herein, our target-based collection of benzimidazole derivatives strongly suggests the utilization of benzimidazole derivatives against BC.

Fenbendazole Suppresses Growth and Induces Apoptosis of Actively Growing H4IIE Hepatocellular Carcinoma Cells via p21-Mediated Cell-Cycle Arrest

Bendimidazole anthelmintics (BAs) have gained interest for their anticancer activity. The anticancer activity is mediated via multiple intracellular changes, which are not consistent under different conditions even in the same cells. We investigated the anticancer activity of fenbendazole (FZ, one of BAs) under two different growth conditions. The growth rate of H4IIE cells was dose-dependently decreased by FZ only in actively growing cells but not in fully confluent quiescent cells. Apoptosis-associated changes were also induced by FZ in actively growing cells. Markers of autophagy were not changed by FZ. The number of cells was markedly increased in sub-G1 phase but decreased in S- and G2/M phases by FZ. FZ up-regulated p21 (an inhibitor of cyclin-CDK) but suppressed the expression of cell cycle-promoting proteins (cyclin D1 and cyclin B1). FZ did not affect integrin αV or n-cadherin expression as well as cell migration. Glycolytic changes (glucose consumption and lactate production) and the generation of reactive oxygen species (ROS) were not affected by FZ. Although the activity of mitogen-activated protein kinases (MAPKs) was altered by FZ, the inhibition of MAPKs did not affect the pro-apoptotic activity of FZ. Taken together, FZ selectively suppressed the growth of cells via p21-mediated cell cycle arrest at G1/S and G2/M, and resulted in apoptosis only in actively growing cells but not in quiescent cells. Glucose metabolism, ROS generation, and MAPKs are unlikely targets of FZ at least in H4IIE rat hepatocellular carcinoma cells used in this study.

Cytotoxic Ruthenium(II) Complexes of Pyrazolylbenzimidazole Ligands That Inhibit VEGFR2 Phosphorylation

Eight new ruthenium(II) complexes of N,N-chelating pyrazolylbenzimidazole ligands of the general formula [Ru^II(p-cym)(L)X]⁺ [where the ligand L is 2-(1H-pyrazol-1-yl)-1H-benzo[d]imidazole (L1) substituted at the 4 position of the pyrazole ring by Cl (L2), Br (L3), or I (L4) and X = Cl^- and I^-] were synthesized and characterized using various analytical techniques. Complexes 1 and 3 were also characterized by single-crystal X-ray crystallography, and they crystallized as a monoclinic crystal system in space groups P2₁/n and P2₁/c, respectively. The complexes display good solution stability at physiological pH 7.4. The iodido-coordinated pyrazolylbenzimidazole ruthenium(II) p-cymene complexes (2, 4, 6, and 8) are more resistant toward hydrolysis and have less tendency to form monoaquated complexes in comparison to their chlorido analogues (1, 3, 5, and 7). The halido-substituted 2-(1H-pyrazol-1-yl)-1H-benzo[d]imidazole ligands, designed as organic-directing molecules, inhibit vascular endothelial growth factor receptor 2 (VEGFR2) phosphorylation. In addition, the ruthenium(II) complexes display a potential to bind to DNA bases. The cytotoxicity profile of the complexes (IC₅₀ ca. 9-12 μM for 4-8) against the triple-negative breast cancer cells (MDA-MB-231) show that most of the complexes are efficient. The lipophilicity and cellular accumulation data of the complexes show a good correlation with the cytotoxicity profile of 1-8. The representative complexes 3 and 7 demonstrate the capability of arresting the cell cycle in the G2/M phase and induce apoptosis. The inhibition of VEGFR2 phosphorylation with the representative ligands L2 and L4 and the corresponding metal complexes 3 and 7 in vitro shows that the organic-directing ligands and their complexes inhibit VEGFR2 phosphorylation. Besides, L2, L4, 3, and 7 inhibit the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and proto-oncogene tyrosine-protein kinase (Src), capable of acting downstream of VEGFR2 as well as independently. Compounds L2, L4, 3, and 7 have a lesser effect on ERK1/2 and more prominently affect Src phosphorylation. We extended the study for L2 and 3 in the Tg(fli1:gfp) zebrafish model and found that L2 is more effective in vivo compared to 3 in inhibiting angiogenesis.

Design and synthesis of novel N-[3-(benzimidazol-2-ylamino)phenyl]amine and N-[3-(benzoxazol-2-ylamino)phenyl]amine derivatives as potential anticancer agents

In this contribution, we report the design, synthesis and cytotoxicity studies of a series of N-[3-(benzimidazol-2-yl-amino)phenyl]amine and N-[3-(benzoxazol-2-ylamino)phenyl]amine derivatives. In vitro cytotoxicity assay of 26 selected compounds was carried out at National Cancer Institute (NCI), USA. Out of them, compounds 10e (NSC D-762842/1) and 11s (NSC D-764942/1) have shown remarkable cytotoxicity with GI₅₀ values ranging between "0.589-14.3 µM" and "0.276-12.3 µM," respectively, in the representative nine subpanels of human tumor cell lines. Further, flow cytometry analysis demonstrated that compound 10e exerted cell cycle arrest at G2/M phase and showed dose-dependent enhancement in apoptosis in K-562 leukemia cancer cells.

New C2- and N3-Modified Thieno[2,3-d]Pyrimidine Conjugates with Cytotoxicity in the Nanomolar Range

AIMS

The aim of the current study was to develop and explore a series of new cytotoxic agents based on the conjugation between the thieno[2,3-d]pyrimidine moiety and a second pharmacophore at the C2 or N3 position.

BACKGROUND

As the thieno[2,3-d]pyrimidine core is a bioisostere of the 4-anilinoquinazoline, various new thienopyrimidine derivatives were synthesized by modifying the structure of the clinically used anticancer quinazoline EGFR inhibitors of the first generation - gefitinib, and second generation - dacomitinib and canertinib. It was reported that some thieno[2,3-d]pyrimidine derivatives showed improved EGFR inhibitory activity. On the other hand, the benzimidazole heterocycle is present as a pharmacophore unit in the structure of many clinically used chemotherapeutic agents. Some 2-aminobenzimidazole derivatives, possessing anticancer activity, demonstrated EGFR inhibition and the benzimidazole derivative EGF816 is currently in the second phase of clinical trials.

OBJECTIVE

The objectives of the study were design of a novel series thieno[2,3-d]pyrimidines, synthesis of the compounds and investigation of their effects towards human cancer HT-29, MDA-MB-231, HeLa, HepG2 and to normal human Lep3 cell lines. (American Type Culture Collection, ATCC, Rockville, MD, USA) Methods: The synthetic protocol implemented cyclocondensation of 2-amino-thiophenes and nitriles in inert medium, aza-Michael addition to benzimidazole derivatives and nucleophylic substitution at the N3 place. MTS test was used in order to establish the cytotoxicity of the tested compounds. SAR analysis and in silico assessment of the inhibitory potential towards human oncogenic V^599EB-Raf were performed using Molinspiration tool and Molecular Operating environment software.

RESULTS

The MTS test data showed that almost all studied thieno[2,3-d]pyirimidines (9-13, 21-22 and 25) manifest high inhibiting effect on the cell proliferation at nanomolar concentrations, whereat compounds 9 (IC₅₀ = 130 nM) and 10 (IC₅₀ = 261 nM) containing amino acid moiety, and 21 (IC₅₀ = 108 nM) possesing two thienopyrimidine moieties attached to a 1,3-disubstituted benzimidazole linker, revealed many times lower toxicity against Lep3 cells compared to the cancer cells. Thienopyrimidines 11-13 possessed high selectivity against HeLa cells. Compound 13 showed high inhibitory activity against MDA-MB-231 and HepG2, with IC50 1.44 nM and 1.11 nM respectively. To outline the possible biological target of the studied coumpounds, their potential to interact with human oncogenic V^599EB-Raf was explored by a docking study. As a result, it was suggested that the benzimidazolyl and glycyl fragments could enhance the binding ability of the new compounds by increasing the number of hydrogen bond acceptors and by stabilizing the inactive form of the enzyme.

CONCLUSION

The thienopyrimidines tested in vitro towards human cancer HT-29, MDA-MB-231, HeLa, HepG2 and normal human Lep3 cell lines demonstrated cytotoxicity in nanomolar range. It was established that compounds 9, 10 and 21 showed many times lower toxicity against normal Lep3 cells that can provide a high selectivity towards all four cancer cell lines at small concentrations. Based on the analysis of the structure-activity relationship, the observed trends in the cytotoxicity could be related to the lipophilicity and the topological polar surface area of the tested compounds. The docking study on the potential of the new thieno[2,3-d]pyrimidine-4-ones to interact with mutant V^599EB-Raf showed that the compounds might be able to stabilize the enzyme in its inactive form.

Pyronaridine induces apoptosis in non-small cell lung cancer cells by upregulating death receptor 5 expression and inhibiting epidermal growth factor receptor

Lung cancer is the leading cause of cancer death. Pyronaridine, a synthetic drug of artemisinin, has been used in China for over 30 years for the treatment of malaria, but its effect on non-small cell lung cancer (NSCLC) cells is rarely reported. In this study, we determined the efficacy of pyronaridine in four different NSCLC cell lines and explored its mechanism in H1975. The data showed that pyronaridine could upregulate the expression of TNF-related apoptosis-inducing ligand (TRAIL)-mediated death receptor 5 to promote cellular apoptosis. Meanwhile, the JNK (c-Jun N-terminal kinase) level was detected to be significantly increased after treating with pyronaridine. We used JNK inhibitor and found that it could partially inhibit cell apoptosis. The results showed that epidermal growth factor receptor (EGFR), PI3K, and AKT were downregulated after the treatment of pyronaridine. In summary, pyronaridine can selectively kill NSCLC by regulating TRAIL-mediated apoptosis and downregulating the protein level of EGFR. It is a promising anticancer drug for NSCLC.

Thieno[2,3-d]pyrimidin-4(3H)-one Derivatives of Benzimidazole as Potential Anti- Breast Cancer (MDA-MB-231, MCF-7) Agents

AIMS

The purpose of this study was the synthesis of some new thienopyrimidine derivatives of 1,3-disubstituted benzimidazoles and the evaluation of their cytotoxicity against MDA-MB-231, MCF-7, and 3T3 cells lines.

BACKGROUND

An overexpression or mutational activation of TK receptors EGFR and HER2/neu is characteristic of tumors. It has been found that some thieno[2,3-d]pyrimidines exhibited better inhibitory activity against Epidermal Growth Factor Receptor (EGFR/ErbB-2) tyrosine kinase in comparison to aminoquinazolines. Breast cancer activity towards MDA-MB-231 and MCF-7 cell lines by inhibiting EGFR was revealed by a novel 2-arylbenzimidazole. This motivated the synthesis of new thienopyrimidines possessing benzimidazole fragments in order to evaluate their cytotoxicity to the above-mentioned cell lines.

OBJECTIVE

The objectives of the study were to design and synthesize a novel series of thieno[2,3-d]pyrimidines bearing biologically active moieties, such as 1,3-disubstituted-benzimidazole heterocycle, structurally similar to diaryl ureas in order to evaluate their cytotoxicity against MDA-MB-231, and MCF-7 breast cancer cell lines.

METHODS

N,N-disubstituted benzimidazole-2-one carbonitriles were synthesized by Aza-Michael addition and used as precursors to generate some of the new thieno[2,3-d]pyrimidines in acidic medium The interaction of chloroethyl-2-thienopyrimidines, 2-amino-benzimidazole and benzimidazol-2-one nitriles under solid-liquid transfer catalysis conditions led to new thienopyrimidines. MTT assay for cell survival was performed in order to evaluate the cytotoxicity of the tested compounds. A fluorescence study was conducted to elucidate some aspects of the mechanism of action.

RESULTS

The effects of nine synthesized compounds were investigated towards MDA-MB-231, MCF-7 and 3T3 cell lines. Thieno[2,3-d]pyirimidine-4-one 16 (IC₅₀ - 0.058μM) and 21 (IC₅₀ - 0.029μM) possess high cytotoxicity against MDA-MB-231 cells after 24h. The most cytotoxic compounds against breast cancer MCF-7 cells was compound 21 (IC₅₀ - 0.074μM), revealing lower cytotoxicity against mouse fibroblast 3T3 cells with IC₅₀ - 0.20μM. SAR analysis was performed. Fluorescence study of the treatment of MDA-MB cells with compound 21 was carried out in order to clarify some aspects of the mechanism of action.

CONCLUSION

The relationship between cytotoxicity of compounds 14 and 20 against MCF-7 and 3T3 cells can suggest a similar mechanism of action. The antitumor potential of the tested compounds proves the necessity for further investigation to estimate the exact inhibition pathway in the cellular processes. The fluorescence study of the treatment of MDA-MB cells with compound 21 showed a rapid process of apoptosis.

Design, synthesis and evaluation of novel ErbB/HDAC multitargeted inhibitors with selectivity in EGFRT790M mutant cell lines

Acquired resistance leads to the failure of EGFR TKIs in NSCLC treatment. A novel series of hydroxamic acid-containing 4-aminoquinazoline derivatives as irreversible ErbB/HDAC multitargeted inhibitors for NSCLC therapy had been designed and synthesized, which displayed weak anti-proliferative activity in several EGFR wild-type cancer cell lines (NCI-H838, SK-BR-3, A549, A431) yet retained moderate activity to EGFR^T790M resistance mutation harboring NCI-H1975 cells. The mechanistic studies revealed that the representative compound 11e was able to inhibit the phosphorylation of EGFR, up-regulate hyperacetylation of histone H3 and even reduce the expression of EGFR and Akt in NCI-H1975 cells. In further assays, compound 11e also showed moderate anti-proliferative activity in other EGFR^T790M harboring tumor cell lines (NCI-H820, Ba/F3_EGFR_Del19-T790M-C797S) and low toxicities in normal cell lines (HL-7702, FHC). This selectivity of designed multitargeted compounds could serve as a potential strategy to circumvent multiple mechanisms of acquired resistance to EGFR-targeted therapy without severe toxicities and side effects resulting from broad inhibition.

Accelerated microdroplet synthesis of benzimidazoles by nucleophilic addition to protonated carboxylic acids

We report a metal-free novel route for the accelerated synthesis of benzimidazole and its derivatives in the ambient atmosphere. The synthetic procedure involves 1,2-aromatic diamines and alkyl or aryl carboxylic acids reacting in electrostatically charged microdroplets generated using a nano-electrospray (nESI) ion source. The reactions are accelerated by orders of magnitude in comparison to the bulk. No other acid, base or catalyst is used. Online analysis of the microdroplet accelerated reaction products is performed by mass spectrometry. We provide evidence for an acid catalyzed reaction mechanism based on identification of the intermediate arylamides. Their dehydration to give benzimidazoles occurs in a subsequent thermally enhanced step. It is suggested that the extraordinary acidity at the droplet surface allows the carboxylic acid to function as a C-centered electrophile. Comparisons of this methodology with data from thin film and bulk synthesis lead to the proposal of three key steps in the reaction: (i) formation of an unusual reagent (protonated carboxylic acid) because of the extraordinary conditions at the droplet interface, (ii) accelerated bimolecular reaction because of limited solvation at the interface and (iii) thermally assisted elimination of water. Eleven examples are shown as evidence of the scope of this chemistry. The accelerated synthesis has been scaled-up to establish the substituent-dependence and to isolate products for NMR characterization.

Treatment with a new benzimidazole derivative bearing a pyrrolidine side chain overcomes sorafenib resistance in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. Currently, sorafenib is the standard first-line drug for patients with advanced HCC. However, long-term exposure to sorafenib often results in reduced sensitivity of tumour cells to the drug, leading to acquired resistance. Therefore, developing new compounds to treat sorafenib resistance is urgently needed. Although benzimidazole and its derivatives have been reported to exert antimicrobial and antitumour effects, the anti-drug resistance potential of these molecules is still unknown. In this study, we established sorafenib-resistant (SR) cell lines and an acquired sorafenib resistance xenograft model. We showed that treatment with a benzimidazole derivative bearing a pyrrolidine side chain (compound 9a) inhibited the proliferation of SR cells by blocking the phosphorylation of AKT, p70S6 and the downstream molecule RPS6. In addition, caspase 3/PARP-dependent apoptotic signals were induced in 9a-treated cells. Regarding epithelial-mesenchymal transition (EMT) activities, 9a treatment significantly suppressed the migration of SR cells. In particular, the levels of EMT-related transcription factors (snail, slug and twist) and mesenchymal markers (vimentin and N-cadherin) were downregulated. In the acquired sorafenib resistance xenograft model, compound 9a administration decreased the growth of tumours with acquired sorafenib resistance and the expression of the HCC markers α-fetoprotein, glypican 3 and survivin. In conclusion, treatment with this compound may be a novel therapeutic strategy for patients with sorafenib resistance.

A novel 2-aminobenzimidazole-based compound Jzu 17 exhibits anti-angiogenesis effects by targeting VEGFR-2 signalling

BACKGROUND AND PURPOSE

Recent development in drug discovery have shown benzimidazole to be an important pharmacophore,. Benzimidazole derivatives exhibit broad-spectrum pharmacological properties including anti-microbial, anti-diabetic and anti-tumour activity. However, whether benzimidazole derivatives are effective in suppressing angiogenesis and its underlying mechanisms remain incompletely understood. In this study, we aim to characterize the anti-angiogenic mechanisms of a novel 2-aminobenzimidazole-based compound, Jzu 17, in an effort to develop novel angiogenesis inhibitor.

EXPERIMENTAL APPROACH

Effects of Jzu 17 on endothelial cell proliferation, migration, invasion, and activation of signalling molecules induced by VEGF-A, were analysed by immunoblotting, MTT, BrdU, migration, and invasion assays. We performed tube formation assay, aorta ring sprouting assay, matrigel plug assay, and a mouse model of metastasis to evaluate ex vivo and in vivo anti-angiogenic effects of Jzu 17.

KEY RESULTS

Jzu 17 inhibited VEGF-A-induced cell proliferation, migration, invasion, and endothelial tube formation of HUVECs. Jzu 17 suppressed VEGF-A-induced microvessel sprouting ex vivo and attenuated VEGF-A- or tumour cell-induced neovascularization in vivo. Jzu 17 also reduced B16F10 melanoma lung metastasis. In addition, Jzu 17 inhibited the phosphorylation of VEGFR-2 and its downstream signalling molecules in VEGF-A-stimulated HUVECs. Results from computer modelling further showed that Jzu 17 binds to VEGFR-2 with high affinity.

CONCLUSIONS AND IMPLICATIONS

Jzu 17 may inhibit endothelial remodelling and suppress angiogenesis through targeting VEGF-A-VEGFR-2 signalling. These results also suggest Jzu 17 as a potential lead compound and warrant the clinical development of similar agents in the treatment of cancer and angiogenesis-related diseases.

High-Throughput Phosphotyrosine Protein Complexes Screening by Photoaffinity-Engineered Protein Scaffold-Based Forward-Phase Protein Array

Low-abundance phosphotyrosine (pTyr)-mediated signaling protein complexes play critical roles in cancer signaling. The precise and comprehensive profiling of these pTyr-mediated protein complexes remains challenging because of their dynamic nature and weak binding affinity. Taking advantage of the SH2 domains modified with trifunctional chemical probes and genetic mutations (termed Photo-pTyr-scaffold), we developed a Photo-pTyr-scaffold-based forward-phase protein array that can be used to specifically capture complexes by developing an engineered SH2 domain, photoaffinity cross-linking, and antibody-based measuring weak pTyr-mediated protein complexes from complex biological samples in a 96-well microplate format. This platform demonstrated good precision for quantitation (R² = 0.99) and high sensitivity by which only 5 μg of whole cell lysates is needed. We successfully applied the technology for profiling the dynamic EGF-stimulation-dependent EGFR signaling protein complexes across four different time courses (i.e., 0, 2, 5, 10, and 30 min) in a high-throughput manner. We further evaluated the modulation of EGFR-GRB2-SHC1 protein complexes by FDA-approved EGFR kinase inhibitor erlotinib, demonstrating the feasibility of this approach for high-throughput drug screening. The Photo-pTyr-scaffold-based forward-phase protein array could be generically applicable for exploring the dynamic pTyr signaling complexes in various biological systems and screening for related drugs in a high-throughput manner.

Design and Synthesis of 2-(5-Phenylindol-3-yl)benzimidazole Derivatives with Antiproliferative Effects towards Triple-Negative Breast Cancer Cells by Activation of ROS-Mediated Mitochondria Dysfunction

Benzimidazole derivatives are widely studied because of their broad-spectrum biological activity, such as antitumor properties and excellent fluorescence performance. Herein, two types of 2-(5-phenylindol-3-yl)benzimidazole derivatives (1 a-1 h and 2 a-2 e) were rationally designed and synthesized. When these compounds were investigated in vitro anti-screening assays, we found that all of them possessed antitumor effect, in particular compound 1 b, which showed an outstanding antiproliferative effect on MDA-MB-231 cells (IC₅₀ ≈2.6 μm). A study of the drug action mechanisms in cells showed that the antitumor activity of the compounds is proportional to their lipophilicity and cellular uptake; the tested compounds all entered the lysosome of MDA-MB-231 cells and caused changes in the levels of reactive oxygen species (ROS), and then caused mitochondrial damage. Apparent differences in the ROS levels for each compound suggest that the lethality of these compounds towards MDA-MB-231 cells is closely related to the ROS levels. Taken together, this study not only provides a theoretical basis for 2-(5-phenylindol-3-yl)benzimidazole anticarcinogens but also offers new thinking on the rational design of next-generation antitumor benzimidazole derivatives.

Development of a versatile DNMT and HDAC inhibitor C02S modulating multiple cancer hallmarks for breast cancer therapy

DNMT and HDAC are closely related to each other and involved in various human diseases especially cancer. These two enzymes have been widely recognized as antitumor targets for drug discovery. Besides, research has indicated that combination therapy consisting of DNMT and HDAC inhibitors exhibited therapeutic advantages. We have reported a DNMT and HDAC dual inhibitor 15a of which the DNMT enzymatic inhibitory potency needs to be improved. Herein we reported the development of a novel dual DNMT and HDAC inhibitor C02S which showed potent enzymatic inhibitory activities against DNMT1, DNMT3A, DNMT3B and HDAC1 with IC50 values of 2.05, 0.93, 1.32, and 4.16 µM, respectively. Further evaluations indicated that C02S could inhibit DNMT and HDAC at cellular levels, thereby inversing mutated methylation and acetylation and increasing expression of tumor suppressor proteins. Moreover, C02S regulated multiple biological processes including inducing apoptosis and G0/G1 cell cycle arrest, inhibiting angiogenesis, blocking migration and invasion, and finally suppressing tumor cells proliferation in vitro and tumor growth in vivo.

Drug library screen reveals benzimidazole derivatives as selective cytotoxic agents for KRAS-mutant lung cancer

KRAS is one of the most frequently mutated oncogenes in human non-small cell lung cancer (NSCLC). Mutations in KRAS are detected in 30% of NSCLC cases, with most of them occurring in codons 12 and 13 and less commonly in others. Despite intense efforts to develop drugs targeting mutant KRAS, no effective therapeutic strategies have been successfully tested in clinical trials. Here, we investigated molecular targets for KRAS-activated lung cancer cells using a drug library. A total of 1271 small molecules were screened in KRAS-mutant and wild-type lung cancer cell lines. The screening identified the cytotoxic effects of benzimidazole derivatives on KRAS-mutant lung cancer cells. Treatments with two benzimidazole derivatives, methiazole and fenbendazole-both of which are structurally specific-yielded significant suppression of the RAS-related signaling pathways in KRAS-mutated cells. Moreover, combinatorial therapy with methiazole and trametinib, a MEK inhibitor, induced synergistic effects in KRAS-mutant lung cancer cells. Our study demonstrates that these benzimidazole derivatives play an important role in suppressing KRAS-mutant lung cancer cells, thus offering a novel combinatorial therapeutic approach against such cancer cells.

Photoaffinity-engineered protein scaffold for systematically exploring native phosphotyrosine signaling complexes in tumor samples

Phosphotyrosine (pTyr)-regulated protein complexes play critical roles in cancer signaling. The systematic characterization of these protein complexes in tumor samples remains a challenge due to their limited access and the transient nature of pTyr-mediated interactions. We developed a hybrid chemical proteomics approach, termed Photo-pTyr-scaffold, by engineering Src homology 2 (SH2) domains, which specifically bind pTyr proteins, with both trifunctional chemical probes and genetic mutations to overcome these challenges. Dynamic SH2 domain-scaffolding protein complexes were efficiently cross-linked under mild UV light, captured by biotin tag, and identified by mass spectrometry. This approach was successfully used to profile native pTyr protein complexes from breast cancer tissue samples on a proteome scale with high selectivity, achieving about 100 times higher sensitivity for detecting pTyr signaling proteins than that afforded by traditional immunohistochemical methods. Among more than 1,000 identified pTyr proteins, receptor tyrosine kinase PDGFRB expressed on cancer-associated fibroblasts was validated as an important intercellular signaling regulator with poor expression correlation to ERBB2, and blockade of PDGFRB signaling could efficiently suppress tumor growth. The Photo-pTyr-scaffold approach may become a generic tool for readily profiling dynamic pTyr signaling complexes in clinically relevant samples.

Anticancer activities of a benzimidazole compound through sirtuin inhibition in colorectal cancer

Aim: This study aims to investigate the mode of action of a novel sirtuin inhibitor (BZD9L1) and its associated molecular pathways in colorectal cancer (CRC) cells. Materials & methods: BZD9L1 was tested against metastatic CRC cell lines to evaluate cytotoxicity, cell cycle and apoptosis, senescence, apoptosis related genes and protein expressions, as well as effect against major cancer signaling pathways. Results & conclusion: BZD9L1 reduced the viability, cell migration and colony forming ability of both HCT 116 and HT-29 metastatic CRC cell lines through apoptosis. BZD9L1 regulated major cancer pathways differently in CRC with different mutation profiles. BZD9L1 exhibited anticancer activities as a cytotoxic drug in CRC and as a promising therapeutic strategy in CRC treatment.

DNA physical interaction mediated b-lymphoma treatment offered by tetra benzimidazole-substituted zinc (ii) phthalocyanine derivative

Role of heterocyclic compounds with nitrogen substitution in therapeutic frontiers is well established. The efforts made in this study are directed to dissect the biological significance of benzimidazole-substituted zinc phthalocyanine derivative. Its capacity to act as an anticancer agent against the 2 B-lymphoma cell lines (low-grade and high-grade malignancy) was found out by recording florescence using Alamar blue dye. Further cytotoxic effect at the DNA level was analyzed by performing agarose gel electrophoresis. Molecular docking studies made mechanistic details crystal clear by showing potential dual binding modes employed for interaction with DNA that include minor groove binding and intercalation between bases. This advocates this derivative as potential anticancer agent and deserves further rounds of mechanistic study for its final journey to serve as a marketed drug.

Preferential Inhibition of Wnt/β-Catenin Signaling by Novel Benzimidazole Compounds in Triple-Negative Breast Cancer

Wnt/β-catenin signaling is upregulated in triple-negative breast cancer (TNBC) compared to other breast cancer subtypes and normal tissues. Current Wnt/β-catenin inhibitors, such as niclosamide, target the pathway nonspecifically and exhibit poor pharmacokinetics/pharmacodynamics in vivo. Niclosamide targets other pathways, including mTOR, STAT3 and Notch. Novel benzimidazoles have been developed to inhibit Wnt/β-catenin signaling with greater specificity. The compounds SRI33576 and SRI35889 were discovered to produce more cytotoxicity in TNBC cell lines than in noncancerous cells. The agents also downregulated Wnt/β-catenin signaling mediators LRP6, cyclin D1, survivin and nuclear active β-catenin. In addition, SRI33576 did not affect mTOR, STAT3 and Notch signaling in TNBC and noncancerous cells. SRI35889 inhibited mTOR signaling less in noncancerous than in cancerous cells, while not affecting STAT3 and Notch pathways. Compounds SRI32529, SRI35357 and SRI35361 were not selectively cytotoxic against TNBC cell lines compared to MCF10A cells. While SRI32529 inhibited Wnt/β-catenin signaling, the compound also mitigated mTOR, STAT3 and Notch signaling. SRI33576 and SRI35889 were identified as cytotoxic and selective inhibitors of Wnt/β-catenin signaling with therapeutic potential to treat TNBC in vivo.

Utility of patient-derived lymphoblastoid cell lines as an ex vivo capecitabine sensitivity prediction model for breast cancer patients

Capecitabine is commonly used in treating breast cancer; however, therapeutic response varies among patients and there is no clinically validated model to predict individual outcomes. Here, we investigated whether drug sensitivity quantified in ex vivo patients' blood-derived cell lines can predict response to capecitabine in vivo. Lymphoblastoid cell lines (LCLs) were established from a cohort of metastatic breast cancer patients (n = 53) who were prospectively monitored during treatment with single agent capecitabine at 2000 mg/m²/day. LCLs were treated with increasing concentrations of 5′-DFUR, a major capecitabine metabolite, to assess patients' ex vivo sensitivity to this drug. Subsequently, ex vivo phenotype was compared to observed patient disease response and drug induced-toxicities. We acquired an independent cohort of breast cancer cell lines and LCLs derived from the same donors from ATCC, compared their sensitivity to 5′-DFUR. As seen in the patient population, we observed large inter-individual variability in response to 5′-DFUR treatment in patient-derived LCLs. Patients whose LCLs were more sensitive to 5′-DFUR had a significantly longer median progression free survival (9-month vs 6-month, log rank p-value = 0.017). In addition, this significant positive correlation for 5′-DFUR sensitivity was replicated in an independent cohort of 8 breast cancer cell lines and LCLs derived from the same donor. Our data suggests that at least a portion of the individual sensitivity to capecitabine is shared between germline tissue and tumor tissue. It also supports the utility of patient-derived LCLs as a predictive model for capecitabine treatment efficacy in breast cancer patients.

Design, synthesis and biological evaluation of novel benzimidazole amidines as potent multi-target inhibitors for the treatment of non-small cell lung cancer

A series of novel amidino 2-substituted benzimidazoles linked to 1,4-disubstituted 1,2,3-triazoles were synthesized by implementation of microwave and ultrasound irradiation in click reaction and subsequent condensation of thus obtained 4-(1,2,3-triazol-1-yl)benzaldehyde with o-phenylenediamines. In vitro antiproliferative screening of compounds performed on human cancer cell lines revealed that p-chlorophenyl-substituted 1,2,3-triazolyl N-isopropylamidine 10c and benzyl-substituted 1,2,3-triazolyl imidazoline 11f benzimidazoles had selective and potent cytostatic activities in the low nM range against non-small cell lung cancer cell line A549, which could be attributed to induction of apoptosis and primary necrosis. Additional Western blot analyses showed different mechanisms of cytostatic activity between compounds 10c and 11f that could be associated with the nature of aromatic substituent at 1-(1,2,3-triazolyl) and amidino moiety at C-5 position of benzimidazole ring. Specifically, compound 11f abrogated the activity of several protein kinases including TGM2, CDK9, SK1 and p38 MAPK, whereas compound 10c did not have profound effect on the activities of CDK9 and TGM2, but instead showed moderate downregulation of SK1 activity concomitant with a significant reduction in p38 MAPK. Further in silico structural analysis demonstrated that compound 11f bound slightly better to the ATP binding site of p38 MAPK compared to 10c, which correlated well with observed stronger decrement in the expression level of phospho-p38 MAPK elicited by 11f in comparison with 10c.

PLOD2 regulated by transcription factor FOXA1 promotes metastasis in NSCLC

In multiple types of tumors, fibrotic collagen is regarded as the 'highway' for cancer cell migration, which is mainly modified by lysyl hydroxylase 2 (PLOD2). The previous findings have demonstrated that the expression of PLOD2 was regulated by multiple factors, including HIF-1α, TGF-β and microRNA-26a/b. Although PLOD2 was confirmed to be related to poor prognosis in lung adenocarcinoma, the regulatory mechanism and function of PLOD2 in human lung adenocarcinoma is poorly understood. On the other hand, upregulation or hyperactivation of epidermal growth factor receptor is considered as a prognostic marker in many cancers, especially in non-small-cell lung cancer (NSCLC). In this study, we found that PLOD2 was elevated in NSCLC specimens and positively links to NSCLC poor prognosis. Gain- and loss-of-function studies and orthotopic implantation metastasis model pinpointed that PLOD2 promotes NSCLC metastasis directly by enhancing migration and indirectly by inducing collagen reorganization. In addition, we revealed that PLOD2 was regulated by PI3K/AKT-FOXA1 axis. The transcription factor FOXA1 directly bound to the PLOD2 promoter, and turned on PLOD2 transcription. In summary, our findings revealed a regulatory mechanism of NSCLC metastasis through EGFR-PI3K/AKT-FOXA1-PLOD2 pathway, and provided PLOD2 as a therapeutic target for NSCLC treatment.

Discovery of 1-(3-aryl-4-chlorophenyl)-3-(p-aryl)urea derivatives against breast cancer by inhibiting PI3K/Akt/mTOR and Hedgehog signalings

PI3K/Akt/mTOR and hedgehog (Hh) signalings are two important pathways in breast cancer, which are usually connected with the drug resistance and cancer migration. Many studies indicated that PI3K/Akt/mTOR inhibitors and Hh inhibitors displayed synergistic effects, and the combination of the two signaling drugs could delay drug resistance and inhibit cancer migration in breast cancer. Therefore, the development of molecules simultaneously inhibiting these two pathways is urgent needed. Based on the structures of PI3K inhibitor buparlisib and Hh inhibitor vismodegib, a series of hybrid structures were designed and synthesized utilizing rational drug design and computer-based drug design. Several compounds displayed excellent antiproliferative activities against several breast cancer cell lines, including triple-negative breast cancer (TNBC) MDA-MB-231 cell. Further mechanistic studies demonstrated that the representative compound 9i could inhibit both PI3K/Akt/mTOR and hedgehog (Hh) signalings by inhibiting the phosphorylation of S6K and Akt as well as decreasing the SAG elevated expression of Gli1. Compound 9i could also induce apoptosis remarkably in T47D and MDA-MB-231 cells. In the transwell assay, 9i showed significant inhibition on the migration of MDA-MB-231.