Antiproliferative Aspect of Benzimidazole Derivatives' Activity and Their Impact on NF-κB Expression

Benzimidazole scaffold as a potent anticancer agent with different mechanisms of action (2016-2023)

Benzimidazole scaffolds have potent anticancer activity due to their structure similarity to nucleoside. In addition, benzimidazoles could function as hydrogen donors or acceptors and bind to different drug targets that participate in cancer progression. The literature had many anticancer agents containing benzimidazole cores that gained much interest. Provoked by our endless interest in benzimidazoles as anticancer agents, we summarized the successful trials of the benzimidazole scaffolds in this concern. Moreover, we discuss the substantial opportunities in cancer treatment using benzimidazole-based drugs that may direct medicinal chemists for a compelling future design of more active chemotherapeutic agents with potential clinical applications. The uniqueness of this work lies in the highlighted benzimidazole scaffold hybridization with different molecules and benzimidazole-metal complexes, detailed mechanisms of action, and the IC50 of the developed compounds determined by different laboratories after 2015.

Activation of p53 signaling and regression of breast and prostate carcinoma cells by spirooxindole-benzimidazole small molecules

This study discusses the synthesis and use of a new library of spirooxindole-benzimidazole compounds as inhibitors of the signal transducer and activator of p53, a protein involved in regulating cell growth and cancer prevention. The text includes the scientific details of the [3 + 2] cycloaddition (32CA) reaction between azomethine ylide 7a and ethylene 3a within the framework of Molecular Electron Density Theory. The mechanism of the 32CA reaction proceeds through a two-stage one-step process, with emphasis on the highly asynchronous transition state structure. The anti-cancer properties of the synthesized compounds, particularly 6a and 6d, were evaluated. The inhibitory effects of these compounds on the growth of tumor cells (MDA-MB 231 and PC-3) were quantified using IC50 values. This study highlights activation of the p53 pathway by compounds 6a and 6d, leading to upregulation of p53 expression and downregulation of cyclin D and NF-κB in treated cells. Additionally, we explored the binding affinity of spirooxindole analogs, particularly compound 6d, to MDM2, a protein involved in regulation of p53. The binding mode and position of compound 6d were compared with those of a co-crystallized standard ligand, suggesting its potential as a lead compound for further preclinical research.

Reinvestigation of Passerini and Ugi scaffolds as multistep apoptotic inducers via dual modulation of caspase 3/7 and P53-MDM2 signaling for halting breast cancer

Selective induction of breast cancer apoptosis is viewed as the mainstay of various ongoing oncology drug discovery programs. Passerini scaffolds have been recently exploited as selective apoptosis inducers via a caspase 3/7 dependent pathway. Herein, the optimized Passerini caspase activators were manipulated to synergistically induce P53-dependent apoptosis via modulating the closely related P53-MDM2 signaling axis. The adopted design rationale and synthetic routes relied on mimicking the general thematic features of lead MDM2 inhibitors incorporating multiple aromatic rings. Accordingly, the cyclization of representative Passerini derivatives and related Ugi compounds into the corresponding diphenylimidazolidine and spiro derivative was performed, resembling the nutlin-based and spiro MDM-2 inhibitors, respectively. The study was also extended to explore the apoptotic induction capacity of the scaffold after simplification and modifications. MTT assay on MCF-7 and MDA-MB231 breast cancer cells compared to normal fibroblasts (WI-38) revealed their promising cytotoxic activities. The flexible Ugi derivatives 3 and 4, cyclic analog 8, Passerini adduct 12, and the thiosemicarbazide derivative 17 were identified as the study hits regarding cytotoxic potency and selectivity, being over 10-folds more potent (IC50 = 0.065-0.096 μM) and safer (SI = 4.4-18.7) than doxorubicin (IC50 = 0.478 μM, SI = 0.569) on MCF-7 cells. They promoted apoptosis induction via caspase 3/7 activation (3.1-4.1 folds) and P53 induction (up to 4 folds). Further apoptosis studies revealed that these compounds enhanced gene expression of BAX by 2 folds and suppressed Bcl-2 expression by 4.29-7.75 folds in the treated MCF-7 cells. Docking simulations displayed their plausible binding modes with the molecular targets and highlighted their structural determinants of activities for further optimization studies. Finally, in silico prediction of the entire library was computationally performed, showing that most of them could be envisioned as drug-like candidates.

Anthelmintic Drugs as Emerging Immune Modulators in Cancer

Despite recent advances in treatment approaches, cancer is still one of the leading causes of death worldwide. Restoration of tumor immune surveillance represents a valid strategy to overcome the acquired resistance and cytotoxicity of conventional therapies in oncology and immunotherapeutic drugs, such as immune checkpoint inhibitors and immunogenic cell death inducers, and has substantially progressed the treatment of several malignancies and improved the clinical management of advanced disease. Unfortunately, because of tumor-intrinsic and/or -extrinsic mechanisms for escaping immune surveillance, only a fraction of patients clinically respond to and benefit from cancer immunotherapy. Accumulating evidence derived from studies of drug repositioning, that is, the strategy to identify new uses for approved or investigational drugs that are outside the scope of the original medical indication, has suggested that some anthelmintic drugs, in addition to their antineoplastic effects, exert important immunomodulatory actions on specific subsets of immune cell and related pathways. In this review, we report and discuss current knowledge on the impact of anthelmintic drugs on host immunity and their potential implication in cancer immunotherapy.

Rational Design, Synthesis, Separation, and Characterization of New Spiroxindoles Combined with Benzimidazole Scaffold as an MDM2 Inhibitor

Rational design for a new spiroxindoles, combined with a benzimidazole scaffold to identify a new murine double minute two (MDM2) inhibitor was synthesized and characterized. The desired spiroxindoles were achieved via a [3+2] cycloaddition reaction approach which afforded the cycloadducts with four asymmetric centers separated in an excellent regioselective and diastereoselective compound. The separated spiroxindoles were subjected to a set of biochemical assays including an NCI cell panel assay, MTT assay, and MDM2 binding analysis by a microscale thermophoresis assay. The anticancer reactivity for the tested compounds showed IC50 (µM) in the range between 3.797–6.879 µM, and compound 7d with IC50 = 3.797 ± 0.205 µM was the most active candidate between the series. The results showed promising results that identified that compound 7a could be inhibited the MDM2 with KD = 2.38 μm. Compound 7a developed a network of interactions with the MDM2 receptor studied in silico by molecular docking.

Novel spirooxindole based benzimidazole scaffold: In vitro, nanoformulation and in vivo studies on anticancer and antimetastatic activity of breast adenocarcinoma

The present work provided in vitro anticancer investigation of novel spirooxindole based benzimidazole scaffold SP1 and its nanoformulation with in vivo evaluation of anticancer and antimetastatic activity as potential drug for breast adenocarcinoma. The synthesized compound SP1 exhibited potent growth inhibitory efficacy against four types of human cancer (breast, prostate, colon and lung) cell lines with IC₅₀ = 2.4, 3.4, 7.24 and 7.81 µM and selectivity index 5.79, 4.08, 1.93 and 1.78 respectively. Flow cytometric analysis illustrated that SP1 exhibited high apoptotic effect on all tested cancer cell lines (38.22-52.3 %). The mode of action of this promising compound was declared by its ability to upregulate the gene expression of p21 (2.29-3.91 folds) with suppressing cyclin D (1.9-8.93 folds) and NF-κB (1.26-1.44 fold) in the treated cancer cells. Also, it enhanced the protein expression of apoptotic marker p53 and moderate binding affinity for MDM2 (K_D;7.94 μM). Notwithstanding these promising impressive findings, its selectivity against cancer cell lines and safety on normal cells were improved by nanoformulation. Therefore, SP1 was formulated as ultra-flexible niosomal nanovesicles (transethoniosomes). The ultra-deformability is attributable to the synergism between ethanol and edge activators in improving the flexibility of the nanovesicular membrane. F8 exhibited high deformability index (DI) of (23.48 ± 1.4). It was found that % SP1 released from the optimized transethoniosomal formula (F8) after 12 h (Q_12h) was 84.17 ± 1.29 % and its entrapment efficiency (%EE) was 76.48 ± 1.44 %. Based upon the very encouraging and promising in vitro results, an in vivo study was carried out in female Balb/c mice weighing (15-25 g). SP1 did halt the proliferation of breast cancer cells as well as suppressed the metastasis in other organs like liver, lung and heart.

Attenuation of Rat Colon Carcinogenesis by Styela plicata Aqueous Extract. Modulation of NF-κB Pathway and Cytoplasmic Sod1 Gene Expression

OBJECTIVE

In search for a unique natural combination of highly active biological components for treatment against colon cancer, we used aqueous extract of Ascidia, Styela plicata (ASCex), a marine invertebrate depending on its richness of high levels of biologically active components as indicated in our previous studies, against rat colon cancer, exploring its underlying mechanisms.

METHODS

Rats chemically initiated for colon cancer were either non-treated or post-treated with highly saturated ASCex for 32 weeks after initiation, other groups of rats were administered ASCex without cancer initiation or served as normal controls.

RESULTS

Rats treated with ASCex alone did not show any signs of non-favored health conditions. Treatment with ASCex after cancer initiation has significantly reduced the average incidences, multiplicities and volumes of colon tumors (adenomas and adenocarcinomas) as compared with the non-treated cancer group. ASCex has also significantly reduced the total numbers of aberrant crypt foci (ACF), surrogate biomarkers for colon cancer as compared with the non-treated cancer group. Moreover, anti-proliferative celluar nucular antigen (PCNA) immunohistochemical staining revealed that ASCex exerted significant antiproliferative characteristics in the carcinogen-treated colonic mucosa as compared with its corresponding control. Also, treatment with ASCex has markedly down-regulated the mRNA expression levels of Nuclear Factor-kappa B (NF-κB), a nuclear transcriptional activator as well as the mRNA expression of the cytoplasmic SOD1 gene which encodes Cu/Zn SOD, the first line defense against superoxide radicals.

CONCLUSION

Collectively, ASCex could act as a potent chemotherapeutic drug against colon cancer, likely through the influence of its rich active metabolites which interfere with various biological pathways including inhibition of protein synthesis during cellular growth and marked induction of antioxidative capacity in the colonic mucosa. This role has been extensively discussed herein.

New Selective Progesterone Receptor Modulators and Their Impact on the RANK/RANKL Complex Activity

Breast cancer depends on women’s age. Its chemotherapy and hormone therapy lead to the loss of bone density and disruption of the skeleton. The proteins RANK and RANKL play a pivotal role in the formation of osteoclasts. It is also well established that the same proteins (RANK and RANKL) are the main molecules that play an important role in mammary stem cell biology. Mammary stem cells guarantee differentiation of the epithelial mammary cells, the growth of which is regulated by the progesterone-induced RANKL signaling pathway. The crosstalk between progesterone receptor, stimulated by progesterone and its analogues results in RANKL to RANK binding and activation of cell proliferation and subsequently unlimited expansion of the breast cancer cells. Therefore downstream regulation of this signaling pathway is desirable. To meet this need, a new class of selective estrogen receptor modulators (SPRMs) with anti- and mesoprogestin function were tested as potential anti-RANK agents. To establish the new feature of SPRMs, the impact of tested SPRMs on RANK-RANKL proteins interaction was tested. Furthermore, the cells proliferation upon RANKL stimulation, as well as NFkB and cyclin D1 expression, induced by tested SPRMs were analyzed. Conducted experiments proved NFkB expression inhibition as well as cyclin D1 expression limitation under asoprisnil and ulipristal treatment. The established paracrine anti-proliferative activity of antiprogestins together with competitive interaction with RANK make this class of compounds attractive for further study in order to deliver more evidence of their anti-RANK activity and potential application in the breast cancer therapy together with its accompanied osteoporosis.