Synthesis, antitumour and antioxidant activities of novel α,β-unsaturated ketones and related heterocyclic analogues: EGFR inhibition and molecular modelling study

Design, synthesis and biological evaluation of a new series of imidazothiazole-hydrazone hybrids as dual EGFR and Akt inhibitors for NSCLC therapy

In search of small molecules for targeted therapy of non-small cell lung carcinoma (NSCLC), an efficient four-step synthetic route was followed for the synthesis of new imidazothiazole-hydrazone hybrids, which were assessed for their cytotoxic effects on human lung adenocarcinoma (A549) and human lung fibroblast (CCD-19Lu) cells. Among them, compounds 4, 6, 13, 16, 17 and 21 exhibited selective cytotoxic activity against A549 cell line. In vitro mechanistic studies were performed to assess their effects on apoptosis, caspase-3, cell cycle, EGFR and Akt in A549 cells. Compounds 6, 16, 17 and 21 promoted apoptotic cell death more than erlotinib. According to the in vitro data, it is quite clear that compound 6 promotes apoptosis through caspase-3 activation and arrests the cell cycle at the G0/G1 phase in A549 cells. Compounds 16 and 17 arrested the cell cycle at the S phase, whereas compounds 4, 13 and 21 caused the cell cycle arrest at the G2/M phase. The most effective EGFR inhibitor in this series was found as compound 13, followed by compounds 17 and 16. Furthermore, Akt inhibitory effects of compounds 16 and 17 in A549 cells were close to that of GSK690693. In particular, it can be concluded that the cytotoxic and apoptotic effects of compounds 16 and 17 are associated with their inhibitory effects on both EGFR and Akt. Molecular docking studies suggest that compounds 16 and 17 interact with crucial amino acid residues in the binding sites of human EGFR (PDB ID: 1M17) and Akt2 (PDB ID: 3D0E). Based on the in silico data, both compounds are predicted to possess favorable oral bioavailability and drug-likeness. Further studies are required to benefit from these compounds as anticancer agents for targeted therapy of NSCLC.

Synthesis, enzyme inhibition assay, and molecular modeling study of novel pyrazolines linked to 4-methylsulfonylphenyl scaffold: antitumor activity and cell cycle analysis

Antitumor activity using 59 cancer cell lines and enzyme inhibitory activity of a newly synthesized pyrazoline-linked 4-methylsulfonylphenyl scaffold (compounds 18a-q) were measured and compared with those of standard drugs. Pyrazolines 18b, 18c, 18f, 18g, 18h, and 18n possessed significant antitumor activity, with a positive cytotoxic effect (PCE) of 22/59, 21/59, 21/59, 48/59, 51/59, and 20/59, respectively. The cancer cell lines HL60, MCF-7, and MDA-MB-231 were used to measure the IC50 values of derivatives 18c, 18g, and 18hvia the MTT assay method, and the results were compared with those of reference drugs. Derivatives 18g and 18h showed potent and broad-spectrum antitumor activities against HL60 (IC50 of 10.43, 8.99 μM, respectively), MCF-7 (IC50 of 11.7 and 12.4 μM, respectively), and MDA-MB-231 (IC50 of 4.07 and 7.18 μM, respectively). Compound 18c exhibited strong antitumor activity against HL60 and MDA-MB-231 cell lines with IC50 values of 8.43 and 12.54 μM, respectively, and moderate antitumor activity against MCF-7 cell lines with an IC50 value of 16.20 μM. Compounds 18c, 18g, and 18h remarkably inhibited VEGFR2 kinase (IC50 = 0.218, 0.168, and 0.135 μM, respectively) compared with the reference drug sorafenib (IC50 = 0.041 μM). Compounds 18g and 18h effectively inhibited HER2 kinase (IC50 = 0.496 and 0.253 μM, respectively) compared with erlotinib (IC50 = 0.085 μM). Compound 18h inhibited EGFR kinase (IC50 = 0.574 μM) with a potency comparable with that of the reference drug erlotinib (IC50 = 0.105 μM). Pyrazolines 18c, 18f, and 18h arrested the S/G2 phase of the cell cycle in HL-60 cells. In addition, derivatives 18c, 18f, and 18h revealed lower Bcl-2 protein expression anti-apoptotic levels and higher Bax, caspase-3, and caspase-9 expression levels. Molecular docking studies of derivative 18h into the binding sites of EGFR, HER2, and VEGFR2 kinases explored the interaction mode of these pyrazoline derivatives and their structural requirements for antitumor activity.

Identification of 3-(5-cyano-6-oxo-pyridin-2-yl)benzenesulfonamides as novel anticancer agents endowed with EGFR inhibitory activity

New 5-cyano-6-oxo-pyridine-based sulfonamides (6a-m and 8a-d) were designed and synthesized to potentially inhibit both the epidermal growth factor receptor (EGFR) and carbonic anhydrase (CA), with anticancer properties. First, the in vitro anticancer activity of each target substance was tested using Henrietta Lacks cancer cell line and M.D. anderson metastasis breast cancer cell line cells. Then, the possible CA inhibition against the human CA isoforms I, II, and IX was investigated, together with the EGFR inhibitory activity, with the most powerful derivatives. The neighboring methoxy group may have had a steric effect on the target sulfonamides, which prevented them from effectively inhibiting the CA isoforms while effectively inhibiting the EGFR. The effects of the 5-cyanopyridine derivatives 6e and 6l on cell-cycle disruption and the apoptotic potential were then investigated. To investigate the binding mechanism and stability of the target molecules, thorough molecular modeling assessments, including docking and dynamic simulation, were performed.

Novel 4-(2-arylidenehydrazineyl)thienopyrimidine derivatives as anticancer EGFR inhibitors: Design, synthesis, biological evaluation, kinome selectivity and in silico insights

The current study discovered fifteen new thieno[2,3-d]pyrimidine derivatives with potential anticancer action, including 5a-l, 6, and 7a-b. Results from the NCI screening revealed that compounds 5f-i and 7a significantly inhibited the proliferation of MDA-MB-468 cells at mean GI% and GI50 levels. Compared to staurosporine, these compounds (5f-i and 7a) demonstrated better safety towards typical WI-38 cells. Compounds 5g and 7a demonstrated the highest inhibition (two-digit nanomolar) when compared to erlotinib when their potency was tested on EGFR kinase. Considering the outcomes above, 5g was examined for its ability to disrupt the cell cycle with trigger apoptosis in breast cancer MDA-MB-468 cell lines. The apoptosis markers Bax, Bcl-2, Caspase-8, and Caspase-9, were detected. In silico molecular docking and dynamic simulation were used to explainthe biological activities of the most potent compound.

Discovery of novel thiazolyl-pyrazolines as dual EGFR and VEGFR-2 inhibitors endowed with in vitro antitumor activity towards non-small lung cancer

New series of thiazolyl-pyrazoline derivatives (7a–7d, 10a–10d and 13a–13f) have been synthesised and assessed for their potential EGFR and VEGFR-2 inhibitory activities. Compounds 10b and 10d exerted potent and selective inhibitory activity towards the two receptor tyrosine kinases; EGFR (IC₅₀ = 40.7 ± 1.0 and 32.5 ± 2.2 nM, respectively) and VEGFR-2 (IC₅₀ = 78.4 ± 1.5 and 43.0 ± 2.4 nM, respectively). The best anti-proliferative activity for the examined thiazolyl-pyrazolines was observed against the non-small lung cancer cells (NSCLC). Compounds 10b and 10d displayed pronounced efficacy against A549 (IC₅₀ = 4.2 and 2.9 µM, respectively) and H441 cell lines (IC₅₀ = 4.8 and 3.8 µM, respectively). Moreover, our results indicated that 10b and 10d were much more effective towards EGFR-mutated NSCLC cell lines (NCI-H1650 and NCI-H1975 cells) than gefitinib. Finally, compounds 10b and 10d induce G2/M cell cycle arrest and apoptosis and inhibit migration in A549 cancerous cells.

Synthesis and Evaluation of Some New 4H-Pyran Derivatives as Antioxidant, Antibacterial and Anti-HCT-116 Cells of CRC, with Molecular Docking, Antiproliferative, Apoptotic and ADME Investigations

Colorectal cancer oncogenesis is linked to dysbiosis, oxidative stress and overexpression of CDK2. The 4H-pyran scaffold is considered an antitumoral, antibacterial and antioxidant lead as well as a CDK2 inhibitor. Herein, certain 4H-pyran derivatives were evaluated as antibacterial, antioxidant and cytotoxic agents against HCT-116 cells. Derivatives 4g and 4j inhibited all the tested Gram-positive isolates, except for B. cereus (ATCC 14579), with lower IC₅₀ values (µM) than ampicillin. In addition, 4g and 4j demonstrated the strongest DPPH scavenging and reducing potencies, with 4j being more efficient than BHT. In cell viability assays, 4d and 4k suppressed the proliferation of HCT-116 cells, with the lowest IC₅₀ values being 75.1 and 85.88 µM, respectively. The results of molecular docking simulations of 4d and 4k, inhibitory kinase assays against CDK2, along with determination of CDK2 protein concentration and the expression level of CDK2 gene in the lysates of HCT-116 treated cells, suggested that these analogues blocked the proliferation of HCT-116 cells by inhibiting kinase activity and downregulating expression levels of CDK2 protein and gene. Moreover, 4d and 4k were found to induce apoptosis in HCT-116 cells via activation of the caspase-3 gene. Lastly, compounds 4g, 4j, 4d and 4k were predicted to comply with Lipinski’s rule of five, and they are expected to possess excellent physiochemical and pharmacokinetic properties suitable for in vivo bioavailability, as predicted by the SwissADME web tool.

Synthesis of Benzalacetophenone Based Isoxazoline and Isoxazole Derivatives

Abstract:

The demand for natural product based drugs with less cost and efficient procedures has become a challenge to researchers. Benzalacetophenone is a natural product based species that is modified into numerous heterocyclic compounds including isoxazoline and isoxazole derivatives. The utility of isoxazoline and oxazole derivatives has been increased for the synthesis of the new and effective chemical entities to serve medicinal chemistry in the past few years. Isoxazoline and isoxazole are fascinating classes of heterocyclic compounds, which belong to N- and O-heterocycles, and are widely used as precursors for the development of drugs. This review highlights the recent work for the synthesis of mono and bis isoxazoline and isoxazole derivatives using stable benzalacetophenone and functionalization of isoxazoline and isoxazole, along with the prevailing biological properties.

A novel biphenyl diester derivative, AB38b, inhibits glioblastoma cell growth via the ROS-AKT/mTOR pathway

AB38b is a novel biphenyl diester derivative synthesized in our laboratory, and it has been shown to improve the pathology of nephropathy and encephalopathy in diabetic mice. Glioblastoma (GBM) is the most lethal brain tumor, without effective drugs to date. The present study aims at investigating the role of AB38b in GBM growth and revealing the underlying molecular mechanisms. We found that AB38b administration showed a dose- and time-dependent inhibition on cell proliferation in multiple immortalized and primary GBM cell lines, but it had no significant effects on human astrocyte cell line. More importantly, AB38b blocked cell cycle progression, induced early apoptosis, decreased the activity of AKT/mTOR pathway, and increased the generation of reactive oxygen species (ROS) in GBM cells. Interestingly, antioxidant treatments could reverse the AB38b-mediated abovementioned effects; overexpression of constitutively active AKT could partially rescue the suppressive effects of Ab38b on GBM cell proliferation. In addition, AB38b administration inhibited the tumor growth, decreased the activity of AKT/mTOR pathway, and prolonged the survival time in GBM animal models, without any adverse influences on the important organs. These findings suggest that AB38b exerts anti-glioma activity via elevating the ROS generation followed by inhibiting the activity of AKT/mTOR pathway.

Synthesis, potential antitumor activity, cell cycle analysis, and multitarget mechanisms of novel hydrazones incorporating a 4-methylsulfonylbenzene scaffold: a molecular docking study

Hydrazone is a bioactive pharmacophore that can be used to design antitumor agents. We synthesised a series of hydrazones (compounds 4–24) incorporating a 4-methylsulfonylbenzene scaffold and analysed their potential antitumor activity. Compounds 6, 9, 16, and 20 had the most antitumor activity with a positive cytotoxic effect (PCE) of 52/59, 27/59, 59/59, and 59/59, respectively, while compounds 5, 10, 14, 15, 18, and 19 had a moderate antitumor activity with a PCE of 11/59–14/59. Compound 20 was the most active and had a mean 50% cell growth inhibition (GI₅₀) of 0.26 µM. Compounds 9 and 20 showed the highest inhibitory activity against COX-2, with a half-maximal inhibitory concentration (IC₅₀) of 2.97 and 6.94 μM, respectively. Compounds 16 and 20 significantly inhibited EGFR (IC₅₀ = 0.2 and 0.19 μM, respectively) and HER2 (IC₅₀ = 0.13 and 0.07 μM, respectively). Molecular docking studies of derivatives 9, 16, and 20 into the binding sites of COX-2, EGFR, and HER2 were carried out to explore the interaction mode and the structural requirements for antitumor activity.

Design, synthesis, and analysis of antiproliferative and apoptosis-inducing activities of nitrile derivatives containing a benzofuran scaffold: EGFR inhibition assay and molecular modelling study

New cyanobenzofurans derivatives 2-12 were synthesised, and their antiproliferative activity was examined compared to doxorubicin and Afatinib (IC₅₀ = 4.17-8.87 and 5.5-11.2 µM, respectively). Compounds 2 and 8 exhibited broad-spectrum activity against HePG2 (IC₅₀ = 16.08-23.67 µM), HCT-116 (IC₅₀ = 8.81-13.85 µM), and MCF-7 (IC₅₀ = 8.36-17.28 µM) cell lines. Compounds 2, 3, 8, 10, and 11 were tested as EGFR-TK inhibitors to demonstrate their possible anti-tumour mechanism compared to gefitinib (IC₅₀ = 0.90 µM). Compounds 2, 3, 10, and 11 displayed significant EGFR TK inhibitory activity with IC₅₀ of 0.81-1.12 µM. Compounds 3 and 11 induced apoptosis at the Pre-G phase and cell cycle arrest at the G2/M phase. They also increased the level of caspase-3 by 5.7- and 7.3-fold, respectively. The molecular docking analysis of compounds 2, 3, 10, and 11 indicated that they could bind to the active site of EGFR TK.

Synthesis and Characterization of Some New Quinoxalin-2(1H)one and 2-Methyl-3H-quinazolin-4-one Derivatives Targeting the Onset and Progression of CRC with SRA, Molecular Docking, and ADMET Analyses

The pathogenesis of colorectal cancer is a multifactorial process. Dysbiosis and the overexpression of COX-2 and LDHA are important effectors in the initiation and development of the disease through chromosomal instability, PGE2 biosynthesis, and induction of the Warburg effect, respectively. Herein, we report the in vitro testing of some new quinoxalinone and quinazolinone Schiff’s bases as: antibacterial, COX-2 and LDHA inhibitors, and anticolorectal agents on HCT-116 and LoVo cells. Moreover, molecular docking and SAR analyses were performed to identify the structural features contributing to the biological activities. Among the synthesized molecules, the most active cytotoxic agent, (6d) was also a COX-2 inhibitor. In silico ADMET studies predicted that (6d) would have high Caco-2 permeability, and %HIA (99.58%), with low BBB permeability, zero hepatotoxicity, and zero risk of sudden cardiac arrest, or mutagenicity. Further, (6d) is not a potential P-gp substrate, instead, it is a possible P-gpI and II inhibitor, therefore, it can prevent or reverse the multidrug resistance of the anticancer drugs. Collectively, (6d) can be considered as a promising lead suitable for further optimization to develop anti-CRC agents or glycoproteins inhibitors.

EGFR/VEGFR-2 dual inhibitor and apoptotic inducer: Design, synthesis, anticancer activity and docking study of new 2-thioxoimidazolidin-4one derivatives

AIMS

EGFR and VEGFR-2 have emerged as promising targets for cancer management as they play a crucial role in tumor growth, angiogenesis and metastasis. A novel series of 2-thioxoimidazolidin-4-one derivatives were synthesized and evaluated as apoptotic inducers and EGFR/VEGFR-2 dual inhibitors.

MAIN METHODS

The cytotoxic activities of all synthesized compounds were tested against MCF-7, HepG2 and A549 cell lines. The molecular mechanism of the most promising cytotoxic compounds was investigated via a series of assays including in vitro EGFR and VEGFR-2 inhibitory activity in MCF-7 cell line. Additionally, levels of p53, Bax, Bcl-2, caspase 7, 9 as well as cell cycle analysis were assessed in MCF-7 cell line to gain better understanding of their apoptotic activity. Molecular docking study was carried out to predict binding pattern of these compounds with EGFR and VEGFR-2 active sites. Finally, in silico ADME and drug-likeness profiling were calculated.

KEY FINDINGS

Compounds 6 and 8a exhibited superior cytotoxic activity compared to sorafenib and erlotinib, against the three tested cell lines. In the same context, 6 and 8a showed better EGFR and VEGFR-2 inhibitory activity compared to the reference compounds. The later effect was further supported by the docking study. Furthermore, these compounds displayed potent apoptotic activity as evident by cell accumulation at pre-G1 phase and cell cycle arrest at G2/M phase together with increased p53, caspae-7 and caspase-9 levels and Bax/Bcl-2 ratio. Finally, synthesized compounds have acceptable drug likeness.

SIGNIFICANCE

Compounds 6 and 8a act as potent dual EGFR/VEGFR-2 inhibitors with evident apoptotic activity.

Isatin-Hydrazones with Multiple Receptor Tyrosine Kinases (RTKs) Inhibitory Activity and In-Silico Binding Mechanism

Recently, we have reported a series of isatin hydrazone, two of them, namely, 3-((2,6-dichlorobenzylidene)hydrazono)indolin-2-one (1) and 3-((2-chloro-6-fluorobenzylidene)hydrazono)indolin-2-one (2) having potent cytotoxicity, showing cyclin-dependent kinases (CDK2) inhibitory activity and bearing recommended drug likeness properties. Since both compounds (1 and 2) showed inhibitory activity against CDK2, we assumed it would also have multiple receptor tyrosine kinases (RTKs) inhibitory activity. Considering those points, here, above-mentioned two isatin hydrazone 1 and 2 were synthesized using previously reported method for further investigation of their potency on RTKs (EGFR, VEGFR-2 and FLT-3) inhibitory activity. As expected, Compound 1 exhibited excellent inhibitory activity against epidermal growth factor receptor (EGFR, IC50 = 0.269 µM), vascular epidermal growth factor receptor 2 (VEGFR-2, IC50 = 0.232 µM) and FMS-like tyrosine kinase-3 (FLT-3, IC50 = 1.535 µM) tyrosine kinases. On the other hand, Compound 2 also exhibited excellent inhibitory activity against EGFR (IC50 = 0.369 µM), VEGFR-2 (IC50 = 0.266 µM) and FLT-3 (IC50 = 0.546 µM) tyrosine kinases. A molecular docking study with EGFR, VEGFR-2 and FLT-3 kinase suggested that both compounds act as type I ATP competitive inhibitors against EGFR and VEGFR-2, and type II ATP non-competitive inhibitors against FLT-3.

Bioactive compounds, antioxidant capacity and antitumoral activity of ethanolic extracts from fruits and seeds of Eugenia involucrata DC

Eugenia involucrata DC. (Myrtaceae) is a native tree species from Brazil that has been scarcely studied. We investigated the phenolic composition, the antioxidant capacity and the antitumoral activity of ethanolic extracts from fruits (FE) and seeds (SE) of E. involucrata. Six anthocyanins were identified by UPLC-PDA/MS/MS in FE, being four derived from cyanidin, and the other ones derived from delphinidin and pelargonidin. Using HPLC-PDA, FE presented a larger number of phenolic compounds (epicatechin, catechin, rutin, ellagic acid, myricetin and quercetin) than SE, which did not show myricetin and quercetin. However, SE showed higher total phenolic content and generally stronger in vitro antioxidant capacity than FE, except that only FE exhibited superoxide radical scavenging activity, which may be attributed to the anthocyanins present in fruits. Additionally, only SE exhibited antitumoral activity in a pancreatic cancer cell line (PANC-1). The antitumoral mechanisms involved imbalance of antioxidant status, alteration of mitochondrial membrane potential, cytoskeleton disassembly and induction of cell death by apoptosis and necrosis. Compared to the standard antitumoral drug gemcitabine, SE exhibited higher antitumoral efficacy and selectivity index. The highest concentration of total phenolics and of specific phenolic compounds bearing antitumoral properties may be related to the antitumoral activity of SE. Our results corroborate previous data of E. involucrata as an important source of bioactive compounds and provide, for the first time, evidences of in vitro antitumoral potential of its seeds on pancreatic cancer cell line.

Design, synthesis, and antitumor activity of novel compounds based on 1,2,4-triazolophthalazine scaffold: Apoptosis-inductive and PCAF-inhibitory effects

The antitumor activity of newly synthesised triazolophthalazines (L-45 analogues) 10-32 was evaluated in human hepatocellular carcinoma (HePG-2), breast cancer (MCF-7), prostate cancer (PC3), and colorectal carcinoma (HCT-116) cells. Compounds 17, 18, 25, and 32 showed potent antitumor activity (IC₅₀, 2.83-13.97 μM), similar to doxorubicin (IC₅₀, 4.17-8.87 μM) and afatinib (IC₅₀, 5.4-11.4 μM). HePG2 was inhibited by compounds 10, 17, 18, 25, 26, and 32 (IC₅₀, 3.06-10.5 μM), similar to doxorubicin (IC₅₀, 4.50 μM) and afatinib (IC₅₀, 5.4 μM). HCT-116 and MCF-7 were susceptible to compounds 10, 17, 18, 25, and 32 (IC₅₀, 2.83-10.36 and 5.69-11.36 μM, respectively), similar to doxorubicin and afatinib (IC₅₀ = 5.23 and 4.17, and 11.4 and 7.1 μM, respectively). Compounds 17, 25, and 32 exerted potent activities against PC3 (IC₅₀, 7.56-12.28 μM) compared with doxorubicin (IC₅₀, 8.87 µM) and afatinib (IC₅₀ 7.7 μM). Compounds 17 and 32 were the strongest PCAF inhibitors (IC₅₀, 5.31 and 10.30 μM, respectively) and compounds 18 and 25 exhibited modest IC₅₀ values (17.09 and 32.96 μM, respectively) compared with bromosporine (IC₅₀, 5.00 μM). Compound 17 was cytotoxic to HePG2 cells (IC₅₀, 3.06 μM), inducing apoptosis in the pre-G phase and arresting the cell cycle in the G2/M phase. Molecular docking for the most active PCAF inhibitors (17 and 32) was performed.

Synthesis, antitumor activity, and molecular docking study of 2-cyclopentyloxyanisole derivatives: mechanistic study of enzyme inhibition

A series of 24 compounds was synthesised based on a 2-cyclopentyloxyanisole scaffold 3–14 and their in vitro antitumor activity was evaluated. Compounds 4a, 4b, 6b, 7b, 13, and 14 had the most potent antitumor activity (IC₅₀ range: 5.13–17.95 μM), compared to those of the reference drugs celecoxib, afatinib, and doxorubicin. The most active derivatives 4a, 4b, 7b, and 13 were evaluated for their inhibitory activity against COX-2, PDE4B, and TNF-α. Compounds 4a and 13 potently inhibited TNF-α (IC₅₀ values: 2.01 and 6.72 μM, respectively) compared with celecoxib (IC₅₀=6.44 μM). Compounds 4b and 13 potently inhibited COX-2 (IC₅₀ values: 1.08 and 1.88 μM, respectively) comparable to that of celecoxib (IC₅₀=0.68 μM). Compounds 4a, 7b, and 13 inhibited PDE4B (IC₅₀ values: 5.62, 5.65, and 3.98 μM, respectively) compared with the reference drug roflumilast (IC₅₀=1.55 μM). The molecular docking of compounds 4b and 13 with the COX-2 and PDE4B binding pockets was studied.

Highlights

Antitumor activity of new synthesized cyclopentyloxyanisole scaffold was evaluated.

The powerful antitumor 4a, 4b, 6b, 7b & 13 were assessed as COX-2, PDE4B & TNF-α inhibitors.

Compounds 4a, 7b, and 13 exhibited COX-2, PDE4B, and TNF-α inhibition.

Compounds 4b and 13 showed strong interactions at the COX-2 and PDE4B binding pockets.

New chalcone-type compounds and 2-pyrazoline derivatives: synthesis and caspase-dependent anticancer activity

Aim: There is a continuous and urgent need for new anticancer agents with novel structures and target selectivity. Methods & results: The anticancer activity of the prepared compounds was assessed against human lung (A549) and stomach (AGS) cancer cell lines and evaluated in the noncancer human lung fibroblast (MRC-5) cell line. 2-Pyrazolines were devoid of toxicity in all cell lines used, chalcones bearing a β-(benz)imidazole moiety being toxic toward AGS cell line. Mechanistic studies showed that these compounds trigger loss of cell viability and mitochondrial membrane potential, while eliciting morphological traits compatible with regulated cell death, which was ultimately shown to derive from caspase activation, specifically caspase-3. Conclusion: Chalcones 1-3 have been identified as new and promising anticancer agents toward the AGS cell line.

Evolution in medicinal chemistry of sorafenib derivatives for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Traditional chemotherapy drugs are hard to reach a satisfactory therapeutic effect since advanced HCC is highly chemo-resistant. Sorafenib is an oral multikinase inhibitor that can suppress tumor cell proliferation, angiogenesis and induce cancer cell apoptosis. However, the poor solubility, rapid metabolism and low bioavailability of sorafenib greatly restricted its further clinical application. During the past decade, numerous sorafenib derivatives have been designed and synthesized to overcome its disadvantages and improve its clinical performance. This article focuses on the therapeutic effects and mechanisms of various sorafenib derivatives with modifications on the N-methylpicolinamide group, urea group, central aromatic ring or others. More importantly, this review summarizes the current status of the structure-activity relationship (SAR) of reported sorafenib derivatives, which can provide some detailed information of future directions for further structural modifications of sorafenib to discovery new anti-tumor drugs with improved clinical performance.

Synthesis, anticancer, apoptosis-inducing activities and EGFR and VEGFR2 assay mechanistic studies of 5,5-diphenylimidazolidine-2,4-dione derivatives: Molecular docking studies

A new series of 5,5-diphenylhydantoin derivatives containing benzylidene or isatin (4–19) was synthesized. Their anticancer activity against HeLa, a cervical cancer cell line, A549, a lung cancer cell line, and MDA-MB-231, a breast cancer cell line, was evaluated. Compounds 13, 16, 17 and 18 exhibited potent anticancer activity with average IC₅₀ values against the tested cell lines of 109, 59, 81 and 113 μM, respectively. Compound 16 showed potent EGFR and VEGFR2 inhibitory activity with IC₅₀ values of 6.17 and 0.09 μM, respectively. In addition, compound 16 induced caspase-dependent apoptosis and reactive oxygen species (ROS) production at 5 and 10 μM. Moreover, a molecular docking simulation was performed for compound 16 and sunitinib to predict the protein-ligand interactions with the active site of VEGFR2.

Design, Synthesis and Docking Studies of Novel Macrocyclic Pentapeptides as Anticancer Multi-Targeted Kinase Inhibitors

A series of macrocyclic pyrido-pentapeptide candidates 2–6 were synthesized by using N,N-bis-[1-carboxy-2-(benzyl)]-2,6-(diaminocarbonyl)pyridine 1a,b as starting material. Structures of the newly synthesized compounds were established by IR, ¹H and ¹³C-NMR, and MS spectral data and elemental analysis. The in-vitro cytotoxicity activity was investigated for all compounds against MCF-7 and HepG-2 cell lines and the majority of the compounds showed potent anticancer activity against the tested cell lines in comparison with the reference drugs. Out of the macrocyclic pyrido-pentapeptide based compounds, 5c showed encouraging inhibitory activity on MCF-7 and HepG-2 cell lines with IC₅₀ values 9.41 ± 1.25 and 7.53 ± 1.33 μM, respectively. Interestingly, 5c also demonstrated multitarget profile and excellent inhibitory activity towards VEGFR-2, CDK-2 and PDGFRβ kinases. Furthermore, molecular modeling studies of the compound 5c revealed its possible binding modes into the active sites of those kinases.

Sorafenib suppresses TGF-β responses by inducing caveolae/lipid raft-mediated internalization/degradation of cell-surface type II TGF-β receptors: Implications in development of effective adjunctive therapy for hepatocellular carcinoma

Sorafenib is the only FDA approved drug for the treatment of advanced hepatocellular carcinoma (HCC) and other malignancies. Studies indicate that TGF-β signalling is associated with tumour progression in HCC. Autocrine and paracrine TGF-β promotes tumour growth and malignancy by inducing epithelial-mesenchymal transition (EMT). Sorafenib is believed to antagonize tumour progression by inhibiting TGF-β-induced EMT. It improves survival of patients but HCC later develops resistance and relapses. The underlying mechanism of resistance is unknown. Understanding of the molecular mechanism of sorafenib inhibition of TGF-β-induced signalling or responses in HCC may lead to development of adjunctive effective therapy for HCC. In this study, we demonstrate that sorafenib suppresses TGF-β responsiveness in hepatoma cells, hepatocytes, and animal liver, mainly by downregulating cell-surface type II TGF-β receptors (TβRII) localized in caveolae/lipid rafts and non-lipid raft microdomains via caveolae/lipid rafts-mediated internalization and degradation. Furthermore, sorafenib-induced downregulation and degradation of cell-surface TβRII is prevented by simultaneous treatment with a caveolae disruptor or lysosomal inhibitors. On the other hand, sorafenib only downregulates cell-surface TβRII localized in caveolae/lipid rafts but not localized in non-lipid raft microdomains in hepatic stellate cells. These results suggest that sorafenib inhibits TGF-β signalling mainly by inducing caveolae/lipid raft-mediated internalization and degradation of cell-surface TβR-II in target cells. They may also imply that treatment with agents which promote formation of caveolae/lipid rafts, TGF-β receptor kinase inhibitors (e.g., LY2157299) or TGF-β peptide antagonists (by liver-targeting delivery) may be considered as effective adjunct therapy with sorafenib for HCC.