Spectroscopic, biochemical and computational studies of bioactive DNA minor groove binders targeting 5'-WGWWCW-3' motif.

Spectroscopic, biochemical, and computational modelling studies have been used to assess the binding capability of a set of minor groove binding (MGB) ligands against the self-complementary DNA sequences 5'-d(CGCACTAGTGCG)-3' and 5'-d(CGCAGTACTGCG)-3'. The ligands were carefully designed to target the DNA response element, 5'-WGWWCW-3', the binding site for several nuclear receptors. Basic 1D 1H NMR spectra of the DNA samples prepared with three MGB ligands show subtle variations suggestive of how each ligand associates with the double helical structure of both DNA sequences. The variations among the investigated ligands were reflected in the line shape and intensity of 1D 1H and 31P-{1H} NMR spectra. Rapid visual inspection of these 1D NMR spectra proves to be beneficial in providing valuable insights on MGB binding molecules. The NMR results were consistent with the findings from both UV DNA denaturation and molecular modelling studies. Both the NMR spectroscopic and computational analyses indicate that the investigated ligands bind to the minor grooves as antiparallel side-by-side dimers in a head-to-tail fashion. Moreover, comparisons with results from biochemical studies offered valuable insights into the mechanism of action, and antitumor activity of MGBs in relation to their structures, essential pre-requisites for future optimization of MGBs as therapeutic agents.

The design, synthesis, biological evaluation, and molecular docking of new 5-aminosalicylamide-4-thiazolinone hybrids as anticancer agents.

New 5-aminosalicylamide-4-thiazolinone hybrids (27) were efficiently synthesized, characterized, and evaluated to explore their structure-activity relationship as anticancer agents. The antiproliferative activities of the new hybrids were evaluated against eight cancer cell lines using the sulforhodamine B assay. The most potent compound (24b) possessed high selectivity on the tested cell lines in the low micromolar range, with much lower effects on normal fibroblast cells (IC50 > 50 µM). The cell lines derived from leukemia (Jurkat), cervix (HeLa), and colon (HCT116) cancers appeared to be the most sensitive, with IC50 of 2 µM. 24b is the N-ethylamide derivative with p-dimethylaminobenzylidene at position 5 of the 4-thiazolinone moiety. Other N-substituents or arylidene derivatives showed lower activity. Hybrids with salicylamides showed lower activity than with methyl salicylate. The results clearly show that the modifications of the carboxy group and arylidene moiety greatly affect the activity. Investigating the possible molecular mechanisms of these hybrids revealed that they act through cell-cycle arrest and induction of apoptosis and epidermal growth factor receptor (EGFR) inhibition. Molecular docking studies rationalize the molecular interactions of 24b with EGFR. This work expands our knowledge of the structural requirements to improve the anticancer activity of 5-aminosalicylic-thiazolinone hybrids and pave the way toward multitarget anticancer salicylates.

The Role of HDACs in the Response of Cancer Cells to Cellular Stress and the Potential for Therapeutic Intervention.

Throughout the process of carcinogenesis, cancer cells develop intricate networks to adapt to a variety of stressful conditions including DNA damage, nutrient deprivation, and hypoxia. These molecular networks encounter genomic instability and mutations coupled with changes in the gene expression programs due to genetic and epigenetic alterations. Histone deacetylases (HDACs) are important modulators of the epigenetic constitution of cancer cells. It has become increasingly known that HDACs have the capacity to regulate various cellular systems through the deacetylation of histone and bounteous nonhistone proteins that are rooted in complex pathways in cancer cells to evade death pathways and immune surveillance. Elucidation of the signaling pathways involved in the adaptive responses to cellular stress and the role of HDACs may lead to the development of novel therapeutic agents. In this article, we overview the dominant stress types including metabolic, oxidative, genotoxic, and proteotoxic stress imposed on cancer cells in the context of HDACs, which guide stress adaptation responses. Next, we expose a closer view on the therapeutic interventions and clinical trials that involve HDACs inhibitors, in addition to highlighting the impact of using HDAC inhibitors in combination with stress-inducing agents for the management of cancer and to overcome the resistance to current cancer therapy.

Metabolomics Analysis Revealed Significant Metabolic Changes in Brain Cancer Cells Treated with Paclitaxel and/or Etoposide.

Cancer of the central nervous system (CNS) is ranked as the 19th most prevalent form of the disease in 2020. This study aims to identify candidate biomarkers and metabolic pathways affected by paclitaxel and etoposide, which serve as potential treatments for glioblastoma, and are linked to the pathogenesis of glioblastoma. We utilized an untargeted metabolomics approach using the highly sensitive ultra-high-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC-ESI-QTOF-MS) for identification. In this study, 92 and 94 metabolites in U87 and U373 cell lines were profiled, respectively. The produced metabolites were then analyzed utilizing t-tests, volcano plots, and enrichment analysis modules. Our analysis revealed distinct metabolites to be significantly dysregulated (nutriacholic acid, L-phenylalanine, L-arginine, guanosine, ADP, hypoxanthine, and guanine), and to a lesser extent, mevalonic acid in paclitaxel and/or etoposide treated cells. Furthermore, both urea and citric acid cycles, and metabolism of polyamines and amino acids (aspartate, arginine, and proline) were significantly enriched. These findings can be used to create a map that can be utilized to assess the antitumor effect of paclitaxel and/or etoposide within the studied cancer cells.

Discovery of novel class of histone deacetylase inhibitors as potential anticancer agents.

Selective inhibition of histone deacetylases (HDACs) is an important strategy in the field of anticancer drug discovery. However, lack of inhibitors that possess high selectivity toward certain HDACs isozymes is associated with adverse side effects that limits their clinical applications. We have initiated a collaborative initiatives between multi-institutions aimed at the discovery of novel and selective HDACs inhibitors. To this end, a phenotypic screening of an in-house pilot library of about 70 small molecules against various HDAC isozymes led to the discovery of five compounds that displayed varying degrees of HDAC isozyme selectivity. The anticancer activities of these molecules were validated using various biological assays including transcriptomic studies. Compounds 15, 14, and 19 possessed selective inhibitory activity against HDAC5, while 28 displayed selective inhibition of HDAC1 and HDAC2. Compound 22 was found to be a selective inhibitor for HDAC3 and HDAC9. Importantly, we discovered a none-hydroxamate based HDAC inhibitor, compound 28, representing a distinct chemical probe of HDAC inhibitors. It contains a trifluoromethyloxadiazolyl moiety (TFMO) as a non-chelating metal-binding group. The new compounds showed potent anti-proliferative activity when tested against MCF7 breast cancer cell line, as well as increased acetylation of histones and induce cells apoptosis. The new compounds apoptotic effects were validated through the upregulation of proapoptotic proteins caspases3 and 7 and downregulation of the antiapoptotic biomarkers C-MYC, BCL2, BCL3 and NFĸB genes. Furthermore, the new compounds arrested cell cycle at different phases, which was confirmed through downregulation of the CDK1, 2, 4, 6, E2F1 and RB1 proteins. Taken together, our findings provide the foundation for the development of new chemical probes as potential lead drug candidates for the treatment of cancer.

Health benefits of cyanidin-3-glucoside as a potent modulator of Nrf2-mediated oxidative stress.

Berries are natural sources of anthocyanins, especially cyanidin-3-glucoside (C3G), and exhibit significant antioxidant, antidiabetic, anti-inflammatory, and cytoprotective effects against various oxidative stress-induced disorders. C3G and its metabolites possess higher absorption and bioavailability, and interaction with gut microbiota may enhance their health benefits. Various in vitro studies have shown the reactive oxygen species (ROS)-mitigating potential of C3G. However, in in vivo models, C3G exerts its cytoprotective properties by regulating the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant-responsive element (ARE) pathway. Despite existing reports stating various health benefits of C3G, its antioxidant potential by modulating the Nrf2 pathway remains less identified. This review discusses the Nrf2-mediated antioxidant response of C3G in modulating oxidative stress against DNA damage, apoptosis, carcinogen toxicity, and inflammatory conditions. Furthermore, we have reviewed the recent clinical trial data to establish cross talk between a berry-rich diet and disease prevention.

Potential Therapeutic Strategies for Lung and Breast Cancers through Understanding the Anti-Angiogenesis Resistance Mechanisms.

Breast and lung cancers are among the top cancer types in terms of incidence and mortality burden worldwide. One of the challenges in the treatment of breast and lung cancers is their resistance to administered drugs, as observed with angiogenesis inhibitors. Based on clinical and pre-clinical findings, these two types of cancers have gained the ability to resist angiogenesis inhibitors through several mechanisms that rely on cellular and extracellular factors. This resistance is mediated through angiogenesis-independent vascularization, and it is related to cancer cells and their microenvironment. The mechanisms that cancer cells utilize include metabolic symbiosis and invasion, and they also take advantage of neighboring cells like macrophages, endothelial cells, myeloid and adipose cells. Overcoming resistance is of great interest, and researchers are investigating possible strategies to enhance sensitivity towards angiogenesis inhibitors. These strategies involved targeting multiple players in angiogenesis, epigenetics, hypoxia, cellular metabolism and the immune system. This review aims to discuss the mechanisms of resistance to angiogenesis inhibitors and to highlight recently developed approaches to overcome this resistance.

Possible combined effect of perindopril and Azilsartan in an experimental model of dementia in rats.

Renin-angiotensin system exerted deleterious effects on learning and cognitive functions through different mechanisms. The present study has been designed to evaluate the protective effect of perindopril and azilsartan as monotherapy or in combination on aluminum chloride (AlCl3) induced neurobehavioral and pathological changes in Alzheimeric rats. Male Wistar rats were divided into nine groups (n = 6); negative control, AlCl3 treated, vehicle, AlCl3 and Azilsartan (3.5 mg/kg, 7 mg/kg) co-treated, AlCl3 and perindopril (0.5 mg/kg, 1 mg/kg) co-treated, AlCl3 and (Azilsartan 3.5 mg/kg + perindopril 0.5 mg/kg), and AlCl3 and (Azilsartan 7 mg/kg + perindopril 1 mg/kg), all groups were treated for consecutive 60 days. Then, memory function was evaluated by the Y- maze test. Amyloid Peptide - 42 (Aß-42), Acetylcholinesterase (AChE), Malondialdehyde (MDA), Tumor necrosis factor (TNF-α) and Nitric Oxide (NO) levels in the hippocampus were assessed with (ELISA) kits. The histopathological studies of the hippocampal dentate gyrus (DG) and Cornu Ammonis-3 (CA3) were also performed. Oral administration of either azilsartan and perindopril alone or in combined for 60 days have shown; improvement of cognitive function, significant reduction in the hippocampal levels of Aß-42, Acetylcholinesterase, Malondialdehyde (MDA), Tumor necrosis factor (TNF-α) and reserved most of histopathological changes in dentate gyrus (DG) and Cornu Ammonis-3 (CA3) that mediated by Alcl3. Our behavioral, biochemical, and histopathological studies indicate that perindopril and azilsartan have neuroprotective effects on the AD model of rats induced by AlCl3, suggesting that perindopril and azilsartan may be a candidate drugs for the treatment of AD.

Modulation of doxorubicin-induced expression of the multidrug resistance gene in breast cancer cells by diltiazem and protection against cardiotoxicity in experimental animals.

BACKGROUND: Doxorubicin (DOX) is one of the most important anticancer agents used in treating breast cancer. However, chronic cardiotoxicity and multidrug resistance limit the chemotherapeutic use of DOX. METHODS: This study aimed to evaluate the capability of calcium channel blocker diltiazem (DIL) to reverse DOX resistance in breast cancer MCF-7 cells and to confer protection against DOX-induced cardiotoxicity in Wistar rats. For this purpose, we explored the effects of DOX on cell cycle phase distribution and expression of ABCB1, FOXO3a, and p53 genes in the presence and absence of DIL (20 µg/ml) and studied the ability of DIL to prevent DOX-induced cardiotoxicity after a single injection of DOX (15 mg/kg) in male Wister rats. RESULTS: We found that compared with DOX alone treatment, DIL + DOX treatment down regulated the ABCB1 gene expression by > fourfold but up regulated the FOXO3a and p53 genes expression by 1.5 fold. DIL treatment conferred protection against DOX-induced cardiotoxicity, as indicated by a decrease in the levels of the cardiac enzyme creatine kinase MB and malondialdehyde and an increase in the total antioxidant capacity and glutathione peroxidase levels. These biochemical results were further confirmed by the histopathological investigation of cardiac cells, which showed normal cardiac cells with central vesicular nuclei and prevention of DOX-induced disruption of normal cardiac architecture in the DIL to DOX group. CONCLUSIONS: Taken together, our results indicate that DIL treatment can reverse the resistance of breast cancer cells to the therapeutic effects of DOX and can protect against DOX-induced cardiotoxicity in rats.

Correction to: Chemosensitizing and nephroprotective effect of resveratrol in cisplatin-treated animals.

[This corrects the article DOI: 10.1186/s12935-014-0152-2.].

Role of flavonoids in thrombotic, cardiovascular, and inflammatory diseases.

The failure of mechanisms of natural anti-coagulation either due to genetic impairment or due to severe external injuries may result in a condition called thrombosis. This is believed to be the primary cause for a variety of life-threatening conditions such as: heart attack, stroke, pulmonary embolism, thrombophlebitis, and deep venous thrombosis (DVT). The growing number of these incidents requires an alternative anti-coagulant or anti-thrombotic agent that has minimal side effects and improved efficiency. For decades, plant polyphenols, especially flavonoids, were known for their vital role in preventing various diseases such as cancer. Mitigating excessive oxidative stress caused by reactive oxygen species (ROS) with anti-oxidant-rich flavonoids may reduce the risk of hyper-activation of platelets, cardiovascular diseases (CVD), pain, and thrombosis. Furthermore, flavonoids may mitigate endothelial dysfunction (ED), which generally correlates to the development of coronary artery and vascular diseases. Flavonoids also reduce the risk of atherosclerosis and atherothrombotic disease by inhibiting excessive tissue factor (TF) availability in the endothelium. Although the role of flavonoids in CVD is widely discussed, to the best of our knowledge, their role as anti-thrombotic lead has not been discussed. This review aims to focus on the biological uses of dietary flavonoids and their role in the treatment of various coagulation disorders, and may provide some potential lead to the drug discovery process in this area.

Dimethylsulfoxide excerbates cisplatin-induced cytotoxicity in Ehrlich ascites carcinoma cells.

BACKGROUND: Cisplatin (CIS) is a potent antineoplastic agent with high therapeutic efficacy against many kinds of tumors. Its use is limited by its nephrotoxicity. The aim of this work was to minimize cisplatin effective dose and the possible reduction of its severe side effects. The present study was designed to assess the role of sulfur containing agent dimethyl sulfoxide (DMSO) on sensitization of mammary carcinoma, Ehrlich ascites carcinoma (EAC), to the action of cisplatin and at the same time the possible protective effect against cisplatin induced nephrotoxicity in experimental animals. METHODS: To evaluate these effects we have explored the cisplatin effect on the survival time of tumor-bearing animals, tumor weight, cisplatin cellular uptake, apoptosis induction and cell cycle distribution and renal function in presence and absence of DMSO. RESULTS: Cisplatin at dose of 4.5 mg/kg increased the mean survival time of tumor bearing mice to 37 days compared with tumor bearing control mice. Pretreatment of tumor bearing mice with DMSO 50 % (2 ml/kg equal to 1 gm/kg) 2 h. before cisplatin showed a significant increase in their mean survival time 43 days compared to cisplatin treated animals. DMSO pretreatment retained rat's serum urea and creatinine levels to normal compared to animals treated with cisplatin alone. CONCLUSION: DMSO pretreatment enhanced the cytotoxic activity of cisplatin against the growth of EAC in vivo and showed protective effects against cisplatin-induce nephrotoxicity.

Chemosensitizing and nephroprotective effect of resveratrol in cisplatin -treated animals.

BACKGROUND: Cisplatin (CIS) is one of the most effective anticancer drug used in the treatment of several solid tumors .Its use is limited by its nephrotoxicity. The present study was designed to assess the role of a natural product resveratrol (RSVL) on sensitization of mammary carcinoma (Ehrlich ascites carcinoma) to the action of CIS and the possible protective effect against CIS-induced nephrotoxicity in rats. METHODS: The percent survival of female tumor bearing mice was used for determination the cytotoxic activity of CIS in the presence or the absence of RSVL. Uptake and cell cycle effect, serum creatinine (CREA), blood urea nitrogen (BUN), Reduced Glutathione (GSH) and histopatholgical examination of kidney tissues after CIS and/or RSVL therapy were also investigated. RESULTS: RSVL increased the intracellular level of CIS in EAC cells and there was a strong correlation between the high cellular level of CIS and its cytotoxicity. CIS at a dose level of 5 mg/kg increased the mean survival time of female tumor bearing mice to 25 days compared with 17 days for tumor-bearing control mice. Administration of RSVL at a dose level of 25 mg/kg simultaneously with CIS increased the mean survival time to 48 days with 60% survival of the tumor-bearing animals. Cell cycle analysis of tumor cells showed that CIS treatment decreases the proliferation index of tumor cells while in presence of RSVL there was more significant inhibitions. Also, CIS treatment caused increase in level of creatinine and blood urea with significant decrease in the GSH level. While, in the presence of RSVL, level of creatinine and blood urea restored to control level. CONCLUSION: This study suggests that RSVL could increase the cytotoxic activity of CIS and protect against its nephrotoxicity.

Deciphering the interplay of histone post-translational modifications in cancer: Co-targeting histone modulators for precision therapy.

Chromatin undergoes dynamic regulation through reversible histone post-translational modifications (PTMs), orchestrated by "writers," "erasers," and "readers" enzymes. Dysregulation of these histone modulators is well implicated in shaping the cancer epigenome and providing avenues for precision therapies. The approval of six drugs for cancer therapy targeting histone modulators, along with the ongoing clinical trials of numerous candidates, represents a significant advancement in the field of precision medicine. Recently, it became apparent that histone PTMs act together in a coordinated manner to control gene expression. The intricate crosstalk of histone PTMs has been reported to be dysregulated in cancer, thus emerging as a critical factor in the complex landscape of cancer development. This formed the foundation of the swift emergence of co-targeting different histone modulators as a new strategy in cancer therapy. This review dissects how histone PTMs, encompassing acetylation, phosphorylation, methylation, SUMOylation and ubiquitination, collaboratively influence the chromatin states and impact cellular processes. Furthermore, we explore the significance of histone modification crosstalk in cancer and discuss the potential of targeting histone modification crosstalk in cancer management. Moreover, we underscore the significant strides made in developing dual epigenetic inhibitors, which hold promise as emerging candidates for effective cancer therapy.

Decoding cell death signalling: Impact on the response of breast cancer cells to approved therapies.

Breast cancer is a principal cause of cancer-related mortality in female worldwide. While many approved therapies have shown promising outcomes in treating breast cancer, understanding the intricate signalling pathways controlling cell death is crucial for optimizing the treatment outcome. A growing body of evidence has unveiled the aberrations in multiple cell death pathways across diverse cancer types, highlighting these pathways as appealing targets for therapeutic interventions. In this review, we provide a comprehensive overview of the current state of knowledge on the cell death signalling mechanisms with a particular focus on their impact on the response of breast cancer cells to approved therapies. Additionally, we discuss the potentials of combination therapies that exploit the synergy between approved drugs and therapeutic agents targeting modulators of cell death pathways.

Design, synthesis and mechanistic anticancer activity of new acetylated 5-aminosalicylate-thiazolinone hybrid derivatives.

The development of hybrid compounds has been widely considered as a promising strategy to circumvent the difficulties that emerge in cancer treatment. The well-established strategy of adding acetyl groups to certain drugs has been demonstrated to enhance their therapeutic efficacy. Based on our previous work, an approach of accommodating two chemical entities into a single structure was implemented to synthesize new acetylated hybrids (HH32 and HH33) from 5-aminosalicylic acid and 4-thiazolinone derivatives. These acetylated hybrids showed potential anticancer activities and distinct metabolomic profile with antiproliferative properties. The in-silico molecular docking predicts a strong binding of HH32 and HH33 to cell cycle regulators, and transcriptomic analysis revealed DNA repair and cell cycle as the main targets of HH33 compounds. These findings were validated using in vitro models. In conclusion, the pleiotropic biological effects of HH32 and HH33 compounds on cancer cells demonstrated a new avenue to develop more potent cancer therapies.

Chemosensetizing and cardioprotective effects of resveratrol in doxorubicin- treated animals.

BACKGROUND: Doxorubicin (DOX), an anthracycline antibiotic is one of the most effective anticancer drug used in the treatment of variety of cancers .Its use is limited by its cardiotoxicity. The present study was designed to assess the role of a natural product resveratrol (RSVL) on sensitization of mammary carcinoma (Ehrlich ascites carcinoma) to the action of DOX and at the same time its protective effect against DOX-induced cardiotoxicity in rats. METHODS: Ehrlich ascites carcinoma bearing mice were used in this study. Percent survival of tumor bearing mice was used for determination of the Cytotoxic activity of DOX in presence and absence of RSVL. Uptake and cell cycle effect of DOX in tumor cells in the presence of RSVL was also determined. Histopatholgical examination of heart tissues after DOX and/or RSVL therapy was also investigated. RESULTS: DOX at a dose level of 15 mg/kg increased the mean survival time of tumor bearing mice to 21 days compared with 15 days for non tumor-bearing control mice. Administration of RSVL at a dose level of 10 mg/kg simultaneously with DOX increased the mean survival time to 30 days with 70% survival of the tumor-bearing animals. RSVL increased the intracellular level of DOX and there was a strong correlation between the high cellular level of DOX and its cytotoxic activity. Moreover, RSVL treatment showed 4.8 fold inhibition in proliferation index of cells treated with DOX. Histopathological analysis of rat heart tissue after a single dose of DOX (20 mg/kg) showed myocytolysis with congestion of blood vessels, cytoplasmic vacuolization and fragmentation. Concomitant treatment with RSVL, fragmentation of the muscle fiber revealed normal muscle fiber. CONCLUSION: This study suggests that RSVL could increase the cytotoxic activity of DOX and at the same time protect against its cardiotoxicity.

Epigenetic modulations in cancer: predictive biomarkers and potential targets for overcoming the resistance to topoisomerase I inhibitors.

INTRODUCTION: Altered epigenetic map is frequently observed in cancer and recent investigations have demonstrated a pertinent role of epigenetic modifications in the response to many anticancer drugs including the DNA damaging agents. Topoisomerase I (Top I) is a well-known nuclear enzyme that is critical for DNA function and cell survival and its inhibition causes DNA strand breaks and cell cycle arrest. Inhibitors of human Top I have proven to be a prosperous chemotherapeutic treatment for a vast number of cancer patients. While the treatment is efficacious in many cases, resistance and altered cellular response remain major therapeutic issues. AREAS COVERED: This review highlights the evidence available till date on the influence of different epigenetic modifications on the response to Top I inhibitors as well as the implications of targeting epigenetic alterations for improving the efficacy and safety of Top I inhibitors. EXPERT OPINION: The field of epigenetic research is steadily growing. With its assistance, we could gain better understanding on how drug response and resistance work. Epigenetics can evolve as possible biomarkers and predictors of response to many medications including Top I inhibitors, and could have significant clinical implications that necessitate deeper attention.HIGHLIGHTSEpigenetic alterations, including DNA methylation and histone modifications, play a pertinent role in the response to several anticancer treatments, including DNA damaging agents like Top I inhibitors.Although camptothecin derivatives are used clinically as Top I inhibitors for management of cancer, certain types of cancer have inherent and or acquired resistance that limit the curative potential of them.Epigenetic modifications like DNA hypomethylation can either increase or decrease sensitivity to Top I inhibitors by different mechanisms.The combination of Top I inhibitors with the inhibitors of histone modifying enzymes can result in enhanced cytotoxic effects and sensitization of resistant cells to Top I inhibitors.MicroRNAs were found to directly influence the expression of Top I and other proteins in cancer cells resulting in positive or negative alteration of the response to Top I inhibitors.lncRNAs and their genetic polymorphisms have been found to be associated with Top I function and the response to its inhibitors.Clinical trials of epigenetic drugs in combination with Top I inhibitors are plentiful and some of them showed potentially promising outcomes.

Modulation of the Tumor Microenvironment by Ellagic Acid in Rat Model for Hepatocellular Carcinoma: A Potential Target against Hepatic Cancer Stem Cells.

The resistance to therapy and relapse in hepatocellular carcinoma (HCC) is highly attributed to hepatic cancer stem cells (HCSCs). HCSCs are under microenvironment control. This work aimed to assess the systemic effect of ellagic acid (EA) on the HCC microenvironment to decline HCSCs. Fifty Wistar rats were divided into six groups: negative control (CON), groups 2 and 3 for solvents (DMSO), and (OVO). Group 4 was administered EA only. The (HCC-M) group, utilized as an HCC model, administered CCL4 (0.5 mL/kg in OVO) 1:1 v/v, i.p) for 16 weeks. HCC-M rats were treated orally with EA (EA + HCC) 50 mg/kg bw for five weeks. Biochemical, morphological, histopathological, and immunohistochemical studies, and gene analysis using qRT-PCR were applied. Results revealed elevated liver injury biomarkers ALT, AST, ALP, and tumor biomarkers AFP and GGT, and marked nodularity of livers of HCC-M. EA effectively reduced the biomarkers and restored the altered structure of the livers. At the mRNA level, EA downregulated the expression of TGF-α, TGF-ß, and VEGF, and restored p53 expression. This induced an increase in apoptotic cells immunostained with caspase3 and decreased the CD44 immunostained HCSCs. EA could modulate the tumor microenvironment in the HCC rat model and ultimately target the HCSCs.

Interaction of an anticancer benzopyrane derivative with DNA: Biophysical, biochemical, and molecular modeling studies.

BACKGROUND: SIMR1281 is a potent anticancer lead candidate with multi- target activity against several proteins; however, its mechanism of action at the molecular level is not fully understood. Revealing the mechanism and the origin of multitarget activity is important for the rational identification and optimization of multitarget drugs. METHODS: We have used a variety of biophysical (circular dichroism, isothermal titration calorimetry, viscosity, and UV DNA melting), biochemical (topoisomerase I & II assays) and computational (molecular docking and MD simulations) methods to study the interaction of SIMR1281 with duplex DNA structures. RESULTS: The biophysical results revealed that SIMR1281 binds to dsDNA via an intercalation-binding mode with an average binding constant of 3.1 × 106 M-1. This binding mode was confirmed by the topoisomerases' inhibition assays and molecular modeling simulations, which showed the intercalation of the benzopyrane moiety between DNA base pairs, while the remaining moieties (thiazole and phenyl rings) sit in the minor groove and interact with the flanking base pairs adjacent to the intercalation site. CONCLUSIONS: The DNA binding characteristics of SIMR1281, which can disrupt/inhibit DNA function as confirmed by the topoisomerases' inhibition assays, indicate that the observed multi-target activity might originate from ligand intervention at nucleic acids level rather than due to direct interactions with multiple biological targets at the protein level. GENERAL SIGNIFICANCE: The findings of this study could be helpful to guide future optimization of benzopyrane-based ligands for therapeutic purposes.