BZD9L1 sirtuin inhibitor as a potential adjuvant for sensitization of colorectal cancer cells to 5-fluorouracil

Transcriptome analysis displays new molecular insights into the mechanisms of action of Mebendazole in gastric cancer cells

Gastric cancer (GC) is a common cancer worldwide. Therefore, searching for effective treatments is essential, and drug repositioning can be a promising strategy to find new potential drugs for GC therapy. For the first time, we sought to identify molecular alterations and validate new mechanisms related to Mebendazole (MBZ) treatment in GC cells through transcriptome analysis using microarray technology. Data revealed 1066 differentially expressed genes (DEGs), of which 345 (2.41 %) genes were upregulated, 721 (5.04 %) genes were downregulated, and 13,231 (92.54 %) genes remained unaltered after MBZ exposure. The overexpressed genes identified were CCL2, IL1A, and CDKN1A. In contrast, the H3C7, H3C11, and H1-5 were the top 3 underexpressed genes. Gene set enrichment analysis (GSEA) identified 8 pathways significantly overexpressed in the treated group (p < 0.05 and FDR<0.25). The validation of the expression of top desregulated genes by RT-qPCR confirmed the transcriptome results, where MBZ increased the CCL2, IL1A, and CDKN1A and reduced the H3C7, H3C11, and H1-5 transcript levels. Expression analysis in samples from TCGA databases correlated that the lower ILI1A and higher H3C11 and H1-5 gene expression are associated with decreased overall survival rates in patients with GC, indicating that MBZ treatment can improve the prognosis of patients. Thus, the data demonstrated that the drug MBZ alters the transcriptome of the AGP-01 lineage, mainly modulating the expression of histone proteins and inflammatory cytokines, indicating a possible epigenetic and immunological effect on tumor cells, these findings highlight new mechanisms of action related to MBZ treatment. Additional studies are still needed to better clarify the epigenetic and immune mechanism of MBZ in the therapy of GC.

Molecular Docking, Synthesis and Biological Evaluation of New Benzimidazole‐Pyridine Derivatives as Potential Aromatase Inhibitor for the Treatment of Cancer

This study describes the synthesis of N5‐(4‐(1H‐benzo[d]imidazol‐2‐yl)phenyl)‐N2‐phenylpyridine‐2,5‐diamine derivatives from Orthophenylenediamine (1) and 4‐aminobenzoic acid (2) and all the synthesized chemical moieties screened against a panel of cancer cell lines resulted in the identification compound 6 a with good anti‐cancer potential and a GI50 of 2.95 μM, 3.35 μM, 2.27 μM, 8.46 nM and 1.56 μM against MDAMB‐231, MCF‐7, A‐549, NCI‐H23 and A‐498 respectively. As the second greatest cause of death globally, cancer continues to pose a serious threat to public health. An essential enzyme called aromatase catalyses the last, rate‐limiting step in the production of oestrogens. As a well‐researched endocrine therapeutic strategy, aromatase inhibitors (AIs) efficiently block the production of oestrogen, which is necessary for aromatase activity.

SIRT1: a novel regulator in colorectal cancer

The class-III histone deacetylase SIRT1 is the most extensively investigated sirtuin deacetylase. It is resistant to the broad deacetylase inhibitor trichostatin A and depends on oxidized nicotinamide adenine nucleotide (NAD+). SIRT1 plays a crucial role in the tumorigenesis of numerous types of cancers, including colorectal cancer (CRC). Accumulating evidence indicates that SIRT1 is a therapeutic target for CRC; however, the function and underlying mechanism of SIRT1 in CRC still need to be elucidated. Herein, we provide a detailed and updated review to illustrate that SIRT1 regulates many processes that go awry in CRC cells, such as apoptosis, autophagy, proliferation, migration, invasion, metastasis, oxidative stress, resistance to chemo-radio therapy, immune evasion, and metabolic reprogramming. Moreover, we closely link our review to the clinical practice of CRC treatment, summarizing the mechanisms and prospects of SIRT1 inhibitors in CRC therapy. SIRT1 inhibitors as monotherapy in CRC or in combination with chemotherapy, radiotherapy, and immune therapies are comprehensively discussed. From epigenetic regulation to its potential therapeutic effect, we hope to offer novel insights and a comprehensive understanding of SIRT1's role in CRC.

The rational modulation of autophagy sensitizes colorectal cancer cells to 5-fluouracil and oxaliplatin

Colorectal cancer (CRC) is the third most common and deadliest cancer globally. Regimens using 5-fluorouracil (5FU) and Oxaliplatin (OXA) are the first-line treatment for CRC, but tumor recurrence is frequent. It is plausible to hypothesize that differential cellular responses are triggered after treatments depending on the genetic background of CRC cells and that the rational modulation of cell tolerance mechanisms like autophagy may reduce the regrowth of CRC cells. This study proposes investigating the cellular mechanisms triggered by CRC cells exposed to 5FU and OXA using a preclinical experimental design mimicking one cycle of the clinical regimen (i.e., 48 h of treatment repeated every 2 weeks). To test this, we treated CRC human cell lines HCT116 and HT29 with the 5FU and OXA, combined or not, for 48 h, followed by analysis for two additional weeks. Compared to single-drug treatments, the co-treatment reduced tumor cell regrowth, clonogenicity and stemness, phenotypes associated with tumor aggressiveness and poor prognosis in clinics. This effect was exerted by the induction of apoptosis and senescence only in the co-treatment. However, a week after treatment, cells that tolerated the treatment had high levels of autophagy features and restored the proliferative phenotype, resembling tumor recurrence. The pharmacologic suppression of early autophagy during its peak of occurrence, but not concomitant with chemotherapeutics, strongly reduced cell regrowth. Overall, our experimental model provides new insights into the cellular mechanisms that underlie the response and tolerance of CRC cells to 5FU and OXA, suggesting optimized, time-specific autophagy inhibition as a new avenue for improving the efficacy of current treatments.

Benzimidazole-Based Derivatives as Apoptotic Antiproliferative Agents: Design, Synthesis, Docking, and Mechanistic Studies

A new class of benzimidazole-based derivatives (4a-j, 5, and 6) with potential dual inhibition of EGFR and BRAFV600E has been developed. The newly synthesized compounds were submitted for testing for antiproliferative activity against the NCI-60 cell line. All newly synthesized compounds 4a-j, 5, and 6 were selected for testing against a panel of sixty cancer cell lines at a single concentration of 10 µM. Some compounds tested demonstrated remarkable antiproliferative activity against the cell lines tested. Compounds 4c, 4e, and 4g were chosen for five-dose testing against 60 human tumor cell lines. Compound 4c demonstrated strong selectivity against the leukemia subpanel, with a selectivity ratio of 5.96 at the GI50 level. The most effective in vitro anti-cancer assay derivatives (4c, 4d, 4e, 4g, and 4h) were tested for EGFR and BRAFV600E inhibition as potential targets for antiproliferative action. The results revealed that compounds 4c and 4e have significant antiproliferative activity as dual EGFR/BRAFV600E inhibitors. Compounds 4c and 4e induced apoptosis by increasing caspase-3, caspase-8, and Bax levels while decreasing the anti-apoptotic Bcl2 protein. Moreover, molecular docking studies confirmed the potential of compounds 4c and 4e to act as dual EGFR/BRAFV600E inhibitors.

BZD9L1 Differentially Regulates Sirtuins in Liver-Derived Cells by Inducing Reactive Oxygen Species

Growing evidence has highlighted that mitochondrial dysfunction contributes to drug-induced toxicities and leads to drug attrition and post-market withdrawals. The acetylation or deacetylation of mitochondrial proteins can affect mitochondrial functions as the cells adapt to various cellular stresses and other metabolic challenges. SIRTs act as critical deacetylases in modulating mitochondrial function in response to drug toxicity, oxidative stress, reactive oxygen species (ROS), and energy metabolism. We previously showed that a recently characterised SIRT inhibitor (BZD9L1) is non-toxic in rodents in a short-term toxicity evaluation. However, the impact of BZD9L1 on mitochondrial function is unknown. This work aims to determine the effects of BZD9L1 on mitochondrial function in human normal liver and kidney-derived cell lines using the Agilent Seahorse Cell Mito Stress Test to complement our short-term toxicity evaluations in vivo. The Mito Stress assay revealed that BZD9L1 could potentially trigger oxidative stress by inducing ROS, which promotes proton leak and reduces coupling efficiency in liver-derived THLE cells. However, the same was not observed in human kidney-derived HEK293 cells. Interestingly, BZD9L1 had no impact on SIRT3 protein expression in both cell lines but affected SOD2 and its acetylated form at 72 h in THLE cells, indicating that BZD9L1 exerted its effect through SIRT3 activity rather than protein expression. In contrast, BZD9L1 reduced SIRT1 protein expression and impacted the p53 protein differently in both cell lines. Although BZD9L1 did not affect the spare respiratory capacity in vitro, these findings call for further validation of mitochondrial function through assessment of other mitochondrial parameters to evaluate the safety of BZD9L1.

Synthesis, characterization, antiproliferative activity, docking, and molecular dynamics simulation of new 1,3-dihydro-2H-benzimidazol-2-one derivatives

Cancer is a global public health problem that affects millions each year. Novel anticancer drug candidates are in need to treat various cancers and to overcome the resistance that exists against drugs in use. Benzimidazole derivatives have been reported as anticancer agents. These lead us to synthesize similar benzimidazole derivatives and investigate their anticancer activity. In this study, six new 1,3-dihydro-2H-benzimidazol-2-one-based molecules (2a-f) were synthesized. The structures of these molecules were verified by spectroscopic methods. The antiproliferative activities of molecules 2a-f were screened against a panel of human cancer cell lines, including the liver, colon, lung, and breast. The molecules were also tested towards normal human lung cell line to determine their selectivity. The results demonstrated that compound 2d had the highest cytotoxic effect compared to compounds 2a-c, 2e, and 2f against DLD-1 and MDA-MB-231 cell lines. The binding potential of the relatively active compound, 2d, with three targets was investigated through molecular docking. The stability of target-compound complexes procured from the docking was explored through molecular dynamics (MD) simulation. The docking and MD simulation studies revealed that compound 2d had the highest potential to bind to GALR3 among the targets. Furthermore, the computational pharmacokinetic study demonstrated that the synthesized compounds had drug-like properties.Communicated by Ramaswamy H. Sarma.

BZD9L1 benzimidazole analogue hampers colorectal tumor progression by impeding angiogenesis

BACKGROUND

The development of new vasculatures (angiogenesis) is indispensable in supplying oxygen and nutrients to fuel tumor growth. Epigenetic dysregulation in the tumor vasculature is critical to colorectal cancer (CRC) progression. Sirtuin (SIRT) enzymes are highly expressed in blood vessels. BZD9L1 benzimidazole analogue is a SIRT 1 and 2 inhibitor with reported anticancer activities in CRC. However, its role has yet to be explored in CRC tumor angiogenesis.

AIM

To investigate the anti-angiogenic potential of BZD9L1 on endothelial cells (EC) in vitro, ex vivo and in HCT116 CRC xenograft in vivo models.

METHODS

EA.hy926 EC were treated with half inhibitory concentration (IC₅₀) (2.5 μM), IC₅₀ (5.0 μM), and double IC₅₀ (10.0 μM) of BZD9L1 and assessed for cell proliferation, adhesion and SIRT 1 and 2 protein expression. Next, 2.5 μM and 5.0 μM of BZD9L1 were employed in downstream in vitro assays, including cell cycle, cell death and sprouting in EC. The effect of BZD9L1 on cell adhesion molecules and SIRT 1 and 2 were assessed via real-time quantitative polymerase chain reaction (qPCR). The growth factors secreted by EC post-treatment were evaluated using the Quantibody Human Angiogenesis Array. Indirect co-culture with HCT116 CRC cells was performed to investigate the impact of growth factors modulated by BZD9L1-treated EC on CRC. The effect of BZD9L1 on sprouting impediment and vessel regression was determined using mouse choroids. HCT116 cells were also injected subcutaneously into nude mice and analyzed for the outcome of BZD9L1 on tumor necrosis, Ki67 protein expression indicative of proliferation, cluster of differentiation 31 (CD31) and CD34 EC markers, and SIRT 1 and 2 genes via hematoxylin and eosin, immunohistochemistry and qPCR, respectively.

RESULTS

BZD9L1 impeded EC proliferation, adhesion, and spheroid sprouting through the downregulation of intercellular adhesion molecule 1, vascular endothelial cadherin, integrin-alpha V, SIRT1 and SIRT2 genes. The compound also arrested the cells at G1 phase and induced apoptosis in the EC. In mouse choroids, BZD9L1 inhibited sprouting and regressed sprouting vessels compared to the negative control. Compared to the negative control, the compound also reduced the protein levels of angiogenin, basic fibroblast growth factor, platelet-derived growth factor and placental growth factor, which then inhibited HCT116 CRC spheroid invasion in co-culture. In addition, a significant reduction in CRC tumor growth was noted alongside the downregulation of human SIRT1 (hSIRT1), hSIRT2, CD31, and CD34 EC markers and murine SIRT2 gene, while the murine SIRT1 gene remained unaffected, compared to vehicle control. Histology analyses revealed that BZD9L1 at low (50 mg/kg) and high (250 mg/kg) doses reduced Ki-67 protein expression, while BZD9L1 at the high dose diminished tumor necrosis compared to vehicle control.

CONCLUSION

These results highlighted the anti-angiogenic potential of BZD9L1 to reduce CRC tumor progression. Furthermore, together with previous anticancer findings, this study provides valuable insights into the potential of BZD9L1 to co-target CRC tumor vasculatures and cancer cells via SIRT1 and/or SIRT2 down-regulation to improve the therapeutic outcome.

Benzimidazole and its derivatives as cancer therapeutics: The potential role from traditional to precision medicine

Cancer is the second leading cause of mortality globally which remains a continuing threat to human health today. Drug insensitivity and resistance are critical hurdles in cancer treatment; therefore, the development of new entities targeting malignant cells is considered a high priority. Targeted therapy is the cornerstone of precision medicine. The synthesis of benzimidazole has garnered the attention of medicinal chemists and biologists due to its remarkable medicinal and pharmacological properties. Benzimidazole has a heterocyclic pharmacophore, which is an essential scaffold in drug and pharmaceutical development. Multiple studies have demonstrated the bioactivities of benzimidazole and its derivatives as potential anticancer therapeutics, either through targeting specific molecules or non-gene-specific strategies. This review provides an update on the mechanism of actions of various benzimidazole derivatives and the structure‒activity relationship from conventional anticancer to precision healthcare and from bench to clinics.

An Individualized EMT-Related Gene Signature to Predict Recurrence-Free Survival in Stage II/III Colorectal Cancer Patients

BACKGROUND

Approximately 30% of stage II and 50-60% of stage III colorectal cancer (CRC) patients who have undergone surgery will develop recurrence within 5 years. Thus, more reliable prognostic biomarkers are urgently needed to identify the high-risk subset of patients who will benefit from postoperative adjuvant therapy.

METHODS

We retrospectively analyzed 911 stage II/III CRC patients in multiple cohorts. Using a series of bioinformatic and statistical approaches, an individualized prognostic signature was established in the training cohort and validated in four other independent cohorts. An integrated decision tree was generated to improve risk stratification, and a nomogram was built to quantify risk assessment for individual patients.

RESULTS

Epithelial-mesenchymal transition (EMT) was identified as a dominant risk factor for recurrence-free survival (RFS) in stage II/III CRC patients. The EMT-related gene signature could discriminate high-risk subsets in a training cohort and four independent validation cohorts (with 473, 89, 130, 74 and 145 patients, respectively). Survival analyses demonstrated that the EMT-related gene signature served as an independent risk factor for RFS in different subgroups. The decision tree could optimize the risk stratification, and the nomogram could predict the 5-year RFS probability accurately.

CONCLUSION

The proposed EMT-related prognostic signature is a useful biomarker to predict RFS and identify the high-risk subset in stage II/III CRC patients.

Antibiotic heliomycin and its water-soluble 4-aminomethylated derivative provoke cell death in T24 bladder cancer cells by targeting sirtuin 1 (SIRT1)

Bladder cancer is one of the most frequent cancers among males, and a poor survival rate reflects problems with aggressiveness and chemo-resistance. Accumulating evidence indicates that SIRT1 is involved in bladder cancer tumorigenesis and is positively associated with chemo-resistance and poor prognosis. We recently synthesized water-soluble chemical derivatives of heliomycin, an antibiotic from Streptomyces resistomycificus, and demonstrated that they possess anticancer properties. In this present study, we used the cellular thermal shift assay (CETSA) in T24 bladder cancer cells to show that heliomycin (designated compound (H1)) and its 4-(tert-butylamino)methyl derivative (HD2) directly engaged with SIRT1 in the native cellular environment, whereas another derivative (HD3) did not. Upon binding, heliomycin downregulated SIRT1 protein expression without altering its transcript level, and subsequently induced autophagy. Interestingly, the derivative (HD2) triggered apoptosis. The interaction between SIRT1 protein and heliomycin or its derivatives was also speculated by a molecular docking simulation, suggesting heliomycin (H1) and derivative (HD2) acting with the different binding modes to SIRT1. Given the increased water-solubility, hydrogen bonds were found on Ala262 and Ile347 residues in the docked complex of derivative (HD2) to produce more steady interaction and initiate signaling pathways that were not observed in the case of heliomycin. Meanwhile, it is evident that derivative (HD3) did not engage with SIRT1 by CETSA or molecular docking studies, nor did it downregulate SIRT1 expression. Taken together, these findings clearly show that SIRT1 is targeted and downregulated by heliomycin and its water-soluble 4-aminomethylated derivative (HD2) possibly through autophagic and/or proteasomal degradation, leading to cell death and growth suppression of T24 bladder cancer cells.

Correlation Analysis of Protein Expression of 10 HDAC/Sirtuin Isoenzymes with Sensitivities of 23 Anticancer Drugs in 17 Cancer Cell Lines and Potentiation of Drug Activity by Co-Treatment with HDAC Inhibitors

Simple Summary

Protein expression profiles of 10 HDAC/Sirtuin isoenzymes in two panels of human cancer cell lines were compared with each other and with the potencies of various anticancer drugs by Pearson and Spearman correlation analysis to identify patterns of enzyme expression and anticancer activity. Furthermore, the NCI COMPARE database was used to identify possible correlations between the mRNA expression in a 60 cancer cell panel and the potency of the same anticancer drugs. While several interesting correlations were found within both data sets, none of these correlations were identical in the two sets of data, suggesting that protein and mRNA expression profiles are not comparable. Combination treatments with several HDAC inhibitors with a number of the anticancer drugs revealed interesting synergistic effects that were in keeping with some of the correlations predicted by our protein expression analysis.

Abstract

Inhibiting the activity of histone deacetylase (HDAC) is an ongoing strategy in anticancer therapy. However, to our knowledge, the relationships between the expression of HDAC proteins and the antitumor drug sensitivity of cancer cells have not been studied until now. In the current work, we investigated the relative expression profiles of 10 HDAC isoenzymes comprising the classes I–III (HDAC1/2/4/6; Sirt1/2/3/5/6/7) in a panel of 17 cancer cell lines, including the breast, cervix, oesophageal, lung, oral squamous, pancreas, as well as urinary bladder carcinoma cells. Correlations between the data of mRNA expression for these enzymes obtained from the National Cancer Institute (NCI) 60 cancer cell line program were also examined. Next, we performed univariate analysis between the expression patterns of HDAC/Sirt isoenzymes with the sensitivity of a 16 cell panel of cancer cell lines towards several antitumor drugs. In a univariate correlation analysis, we found a strong relation between Sirt2 expression and cytotoxicity caused by busulfan, etoposide, and hydroxyurea. Moreover, it was identified that Sirt5 correlates with the effects exerted by oxaliplatin or topotecan, as well as between HDAC4 expression and these two drugs. Correlations between the data of mRNA expression for enzymes with the potencies of the same anticancer agents obtained from the NCI 60 cancer cell line program were also found, but none were the same as those we found with our protein expression data. Additionally, we report here the effects upon combination of the approved HDAC inhibitor vorinostat and one other known inhibitor trichostatin A as well as newer hetero-stilbene and diazeno based sirtuin inhibitors on the potency of cisplatin, lomustine, and topotecan. For these three anticancer drugs, we found a significantly enhanced cytotoxicity when co-incubated with HDAC inhibitors, demonstrating a potentially beneficial influence of HDAC inhibition on anticancer drug treatment.

Sirtuin Modulators in Cellular and Animal Models of Human Diseases

Sirtuins use NAD⁺ to remove various acyl groups from protein lysine residues. Through working on different substrate proteins, they display many biological functions, including regulation of cell proliferation, genome stability, metabolism, and cell migration. There are seven sirtuins in humans, SIRT1-7, each with unique enzymatic activities, regulatory mechanisms, subcellular localizations, and substrate scopes. They have been indicated in many human diseases, including cancer, neurodegeneration, microbial infection, metabolic and autoimmune diseases. Consequently, interests in development of sirtuin modulators have increased in the past decade. In this brief review, we specifically summarize genetic and pharmacological modulations of sirtuins in cancer, neurological, and cardiovascular diseases. We further anticipate this review will be helpful for scrutinizing the significance of sirtuins in the studied diseases.

BZD9L1 sirtuin inhibitor: Identification of key molecular targets and their biological functions in HCT 116 colorectal cancer cells

BZD9L1 was previously described as a SIRT1/2 inhibitor with anti-cancer activities in colorectal cancer (CRC), either as a standalone chemotherapy or in combination with 5-fluorouracil. BZD9L1 was reported to induce apoptosis in CRC cells; however, the network of intracellular pathways and crosstalk between molecular players mediated by BZD9L1 is not fully understood. This study aimed to uncover the mechanisms involved in BZD9L1-mediated cytotoxicity based on previous and new findings for the prediction and identification of related pathways and key molecular players. BZD9L1-regulated candidate targets (RCTs) were identified using a range of molecular, cell-based and biochemical techniques on the HCT 116 cell line. BZD9L1 regulated major cancer pathways including Notch, p53, cell cycle, NFκB, Myc/MAX, and MAPK/ERK signalling pathways. BZD9L1 also induced reactive oxygen species (ROS), regulated apoptosis-related proteins, and altered cell polarity and adhesion profiles. In silico analyses revealed that most RCTs were interconnected, and were involved in the modulation of catalytic activity, metabolism and transcription regulation, response to cytokines, and apoptosis signalling pathways. These RCTs were implicated in p53-dependent apoptosis pathway. This study provides the first assessment of possible associations of molecular players underlying the cytotoxic activity of BZD9L1, and establishes the links between RCTs and apoptosis through the p53 pathway.

MicroRNA-199b Downregulation Confers Resistance to 5-Fluorouracil Treatment and Predicts Poor Outcome and Response to Neoadjuvant Chemoradiotherapy in Locally Advanced Rectal Cancer Patients

Neoadjuvant 5-fluorouracil (5-FU)-based chemoradiotherapy followed by mesorectal excision is the current standard treatment in locally advanced rectal cancer (LARC) and the lack of complete response represents a major problem that compromises long-term patient survival. However, there is a lack of robust established markers predictive of response to this preoperative treatment available in the clinical routine. The tumor suppressor microRNA (miR)-199b directly targets the PP2A inhibitor SET, which has been involved in 5-FU resistance, and its downregulation has been found to correlate with poor outcome in metastatic colorectal cancer. Here, we studied the functional effects of miR-199b on 5-FU sensitivity after its ectopic modulation, and its expression was quantified by real-time-PCR in a cohort of 110 LARC patients to evaluate its potential clinical significance. Interestingly, our findings demonstrate that miR-199b enhances the sensitivity of colorectal cancer cells to 5-FU in a SET-dependent manner, and that both miR-199b overexpression and SET inhibition are able to overcome resistance to this drug using an acquired 5-FU-resistant model. MiR-199b was found downregulated in 26.4% of cases and was associated with positive lymph node levels after chemoradiotherapy (CRT, p = 0.007) and high pathological stage (p = 0.029). Moreover, miR-199b downregulation determined shorter overall (p = 0.003) and event-free survival (p = 0.005), and was an independent predictor of poor response to preoperative CRT (p = 0.004). In conclusion, our findings highlight the clinical impact of miR-199b downregulation predicting poor outcome and pathological response in LARC, and suggest the miR-199b/SET signaling axis as a novel molecular target to prevent the development of resistance to 5-FU treatment.