Design, synthesis, and antitumor efficacy of novel 5-deazaflavin derivatives backed by kinase screening, docking, and ADME studies.

Novel 5-deazaflavins were designed as potential anticancer candidates. Compounds 4j, 4k, 5b, 5i, and 9f demonstrated high cytotoxicity against MCF-7 cell line with IC50 of 0.5-190nM. Compounds 8c and 9g showed preferential activity against Hela cells (IC50: 1.69 and 1.52 µM respectively). However, compound 5d showed notable potency against MCF-7 and Hela cell lines of 0.1 nM and 1.26 µM respectively. Kinase profiling for 4e showed the highest inhibition against a 20 kinase panel. Additionally, ADME prediction studies exhibited that compounds 4j, 5d, 5f, and 9f have drug-likeness criteria to be considered promising antitumor agents deserving of further investigation. SAR study showed that substitutions with 2-benzylidene hydra zino have a better fitting into PTK with enhanced antiproliferative potency. Noteworthy, the incorporation of hydrazino or ethanolamine moieties at position 2 along with small alkyl or phenyl at N-10, respectively revealed an extraordinary potency against MCF-7 cells with IC50 values in the nanomolar range.

Antitumor and multikinase inhibition activities of some synthesized coumarin and benzofuran derivatives.

Two new series of coumarin and benzofuran derivatives were designed, synthesized, and assessed for their in vitro and in vivo antitumor activities against breast cancer. Compounds 8, 9, 14, 15, and 17 exhibited the best antiproliferative activities (IC50 : 0.07-2.94 µM) against the MCF-7 cell line, compared with lapatinib (IC50 : 4.69 µM). Compound 14, with the most potent cytotoxic activity against MCF-7 cells, was capable of enhancing preG1 apoptosis and triggering cell cycle arrest at the G2/M phase. The kinase inhibitory activity of compound 14 against a panel of 22 kinases was examined to reveal multikinase inhibition within -39% to -97%. Furthermore, compound 14 exhibited potent in vivo Ehrlich (mammary adenocarcinoma) tumor regression, positive caspase-3, and negative EGFR immunoreaction, and was capable of elevating the catalase level. The physicochemical properties and pharmacokinetic parameters of compound 14 were investigated in silico for its druglikeness.

Design, Synthesis, Antitumor Activity and Molecular Docking Study of Novel 5-Deazaalloxazine Analogs.

Protein tyrosine kinases (PTKs) are the most potential therapeutic targets for cancer. Herein, we present a sound rationale for synthesis of a series of novel 2-(methylthio), 2-(substituted alkylamino), 2-(heterocyclic substituted), 2-amino, 2,4-dioxo and 2-deoxo-5-deazaalloxazine derivatives by applying structure-based drug design (SBDD) using AutoDock 4.2. Their antitumor activities against human CCRF-HSB-2, KB, MCF-7 and HeLa have been investigated in vitro. Many 5-deazaalloxazine analogs revealed high selective activities against MCF-7 tumor cell lines (IC50: 0.17-2.17 µM) over HeLa tumor cell lines (IC50 > 100 µM). Protein kinase profiling revealed that compound 3h induced multi- targets kinase inhibition including -43% against (FAK), -40% against (CDKI) and -36% against (SCR). Moreover, the Annexin-V/PI apoptotic assay elucidate that compound 3h showed 33% and potentially 140% increase in early and late apoptosis to MCF-7 cells respectively, compared to the control. The structure-activity relationship (SAR) and molecular docking study using PTK as a target enzyme for the synthesized 7-deazaalloaxazine derivatives were investigated as potential antitumor agents. The AutoDock binding affinities of the 5-deazaalloxazine analogs into c-kit PTK (PDB code: 1t46) revealed reasonable correlations between their AutoDock binding free energy and IC50.

Design and molecular modeling of novel P38α MAPK inhibitors targeting breast cancer, synthesized from oxygen heterocyclic natural compounds.

Two new series of furochromone and benzofuran derivatives were designed, synthesized and evaluated for their in vitro anticancer activity against MCF-7 and MDA231 breast cancer cell lines. Compounds 5, 6, 7, 9, 15a, 16, 17a and 18 exhibited the best antiproliferative activities with IC50 values ranging from 1.19 to 2.78 µM against MCF-7 superior to lapatinib as reference standard (IC50; 4.69 µM). Compounds 15a and 18 revealed significant cytotoxic activity against MCF-7 and MDA231, therefore their inhibitory potencies against p38α MAP kinase were evaluated. Remarkably they exhibited significant IC50 of 0.04 µM comparable to SB203580 (IC50; 0.50 µM) as a reference standard. These promising results of cytotoxic activity and significant inhibition of p38α MAP kinase, were confirmed by exploring the effect of benzofuran derivative (18) on the apoptotic induction and cell cycle progression of MCF-7 cell line. Compound 18 induced preG1 apoptosis and cell growth arrest at G2/M phase preventing the mitotic cycle. Moreover it activated the caspase-7 which executes apoptosis. Molecular docking study was carried out using GOLD program to predict the mode of binding interaction of the synthesized compounds into the target p38α MAPK. Additionally, the physicochemical properties and ADME parameters of compound 18 were examined in silico to investigate its drug-likeness.

Synthesis and molecular docking study of new benzofuran and furo[3,2-g]chromone-based cytotoxic agents against breast cancer and p38α MAP kinase inhibitors.

This study deals with synthesis of a new set of benzofuran and 5H-furo[3,2-g]chromone linked various heterocyclic functionalities using concise synthetic approaches aiming to gain new antiproliferative candidates against MCF-7 breast cancer cells of p38α MAP kinase inhibiting activity. The biological data proved the significant sensitivity of breast cancer cell lines MCF-7 towards most of the prepared compounds in comparison with doxorubicin. In addition, compounds IIa,b, Va,b, VIa,b, VIIa,b, VIIIa,b, XIc showed significant in vitro p38α MAPK inhibiting potency comparable to the reference standard SB203580. Cell cycle analysis and apoptosis detection data demonstrated that compound VIa induced G2/M phase arrest and apoptosis in MCF-7 cancer cells, in addition to its activation of the caspases-9 and -3. Gold molecular docking studies rationalized the highly acceptable correlation between the calculated docking scores of fitness and the biological data of p38α MAP kinase inhibition. The newly prepared benzofuran and 5H-furo[3,2-g]chromone derivatives might be considered as new promising nuclei in anti-breast cancer chemotherapeutics for further functionalization, optimization and in-depth biological studies.

Pyrrolizines: Design, synthesis, anticancer evaluation and investigation of the potential mechanism of action.

A novel set of pyrrolizine-5-carboxamides has been synthesized and evaluated for their anticancer potential against human breast MCF-7, lung carcinoma A549 and hepatoma Hep3B cancer cell lines. Compound 10c was the most active against MCF-7 with IC50 value of 4.72µM, while compound 12b was the most active against A549 and Hep3B cell lines. Moreover, kinases/COXs inhibition and apoptosis induction were suggested as potential molecular mechanisms for the anticancer activity of the novel pyrrolizines based on their structural features. The new compounds significantly inhibited COX-1 and COX-2 with IC50 values in the ranges of 5.78-11.96µM and 0.1-0.78µM, respectively with high COX-2 selectivity over COX-1. Interestingly, the most potent compound in MTT assay, compound 12b, exhibited high inhibitory activity against COX-2 with selectivity index (COX-1/COX-2)>100. Meanwhile, compound 12b displayed weak to moderate inhibition of six kinases with inhibition% (7-20%) compared to imatinib (inhibition%=1-38%). The results of cell cycle analysis, annexin V PI/FITC apoptosis assay and caspase-3/7 assay revealed that compound 12b has the ability to induce apoptosis. The docking results of compound 12b into the active sites of COXs, ALK1 and Aurora kinases indicated that it fits nicely inside their active sites. Overall, the current study highlighted the significant anticancer activity of the newly synthesized pyrrolizines with a potential multi-targeted mechanism which could serve as a base for future studies and further structural optimization into potential anticancer agents.

Synthesis and molecular docking studies of new furochromone derivatives as p38α MAPK inhibitors targeting human breast cancer MCF-7 cells.

Based on the reported high expression of p38α MAP kinase in invasive breast cancers and the activity of different functionalized chromone derivatives as p38α inhibitors, a new set of 4,9-dimethoxy/4-methoxy-7-methyl-5-oxo-5H-furo[3,2-g]chromone derivatives were efficiently synthesized aiming to introduce new p38α MAP kinase suppressors as new anti-breast cancer tools. Using GOLD program, molecular docking study of the target compounds into p38α MAP kinase binding pocket was performed to highlight their scores, mode of binding and the important interactions to the amino acid residues of the enzyme. MTT assay investigated that fifteen target compounds produced marked cytotoxic potency higher than that obtained by Doxorubicin against MCF-7 cancer cells of IC50 values ranging from 0.007 to 0.17µM vs IC50; 0.62µM of doxorubicin. Eleven selected compounds were evaluated for their inhibitory potency against p38α MAPK kinase. The derivatives IVa, Va,b, VIa, IXb and XIIIa represented significant activity (IC50; 0.19-0.67µM) comparing to the reference drug SB203580 (IC50; 0.50µM). In virtue of its promising cytotoxic and p38α MAP kinase inhibition potency, the furochromone derivative IXb was selected as a representative example to investigate its mechanistic effects on cell cycle progression and induction of apoptosis in MCF-7 cell lines. The results showed that the compound IXb induced cell cycle cessation at G2/M phase preventing its mitotic cycle, alongside its noteworthy activation of caspases-9 and -3 which might mediate the apoptosis of MCF-7 cells.

Design, Synthesis, and Biological Evaluation of Some Novel Pyrrolizine Derivatives as COX Inhibitors with Anti-Inflammatory/Analgesic Activities and Low Ulcerogenic Liability.

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most commonly prescribed anti-inflammatory and pain relief medications. However, their use is associated with many drawbacks, including mainly serious gastric and renal complications. In an attempt to circumvent these risks, a set of N-(4-bromophenyl)-7-cyano-6-substituted-H-pyrrolizine-5-carboxamide derivatives were designed, synthesized and evaluated as dual COX/5-LOX inhibitors. The structural elucidation, in vivo anti-inflammatory and analgesic activities using a carrageenan-induced rat paw edema model and hot plate assay, were performed, respectively. From the results obtained, it was found that the newly synthesized pyrrolizines exhibited IC50 values in the range of 2.45-5.69 µM and 0.85-3.44 µM for COX-1 and COX-2, respectively. Interestingly, compounds 12, 13, 16 and 17 showed higher anti-inflammatory and analgesic activities compared to ibuprofen. Among these derivatives, compounds 16 and 19 displayed better safety profile than ibuprofen in acute ulcerogenicity and histopathological studies. Furthermore, the docking studies revealed that compound 17 fits nicely into COX-1 and COX-2 binding sites with the highest binding affinity, while compound 16 exerted the highest binding affinity for 5-LOX. In light of these findings, these novel pyrrolizine-5-carboxamide derivatives represent a promising scaffold for further development into potential dual COX/5-LOX inhibitors with safer gastric profile.

Synthesis, biological evaluation, and docking studies of new 2-furylbenzimidazoles as anti-angiogenic agents: part II.

The 2-(5-methyl-2-furyl)-1H-benzimidazole moiety has shown promising activity against vascular endothelial growth factor (VEGF)-induced angiogenesis. In part I of this study, we have synthesized new analogs and tested their anti-angiogenic potentials. Here, we continue our previous study with different new analogs. Some compounds show promising cytotoxic activity against the human breast cancer cell line MCF-7, with IC50 in the range of 7.80-13.90 µg/mL, and exhibited remarkable in vitro inhibition against VEGF in the MCF-7 cancer cell line, with 95-98% of inhibition in comparison to tamoxifen as reference (IC50: 8.00 µg/mL, % of inhibition = 98%). Additionally, a molecular docking study was carried out to gain insight into plausible binding modes and to understand the structure-activity relationships of the synthesized compounds.

Synthesis, docking and biological activities of novel hybrids celecoxib and anthraquinone analogs as potent cytotoxic agents.

Herein, novel hybrid compounds of celecoxib and 2-aminoanthraquinone derivatives have been synthesized using condensation reactions of celecoxib with 2-aminoanthraquinone derivatives or 2-aminoanthraquinon with celecoxib derivatives. Celecoxib was reacted with different acid chlorides, 2-chloroethylisocyanate and bis (2-chloroethyl) amine hydrochloride. These intermediates were then reacted with 2-aminoanthraquinone. Also the same different acid chlorides and 2-chloroethylisocyanate were reacted with 2-aminoanthraquinone and the resulting intermediates were reacted with celecoxib to give isomers for the previous compounds. The antitumor activities against hepatic carcinoma tumor cell line (HEPG2) have been investigated in vitro, and all these compounds showed promising activities, especially compound 3c, 7, and 12. Flexible docking studies involving AutoDock 4.2 was investigated to identify the potential binding affinities and the mode of interaction of the hybrid compounds into two protein tyrosine kinases namely, SRC (Pp60v-src) and platelet-derived growth factor receptor, PDGFR (c-Kit). The compounds in this study have a preferential affinity for the c-Kit PDGFR PTK over the non-receptor tyrosine kinase SRC (Pp60v-src).

Design, synthesis, biological evaluation, and comparative Cox1 and Cox2 docking of p-substituted benzylidenamino phenyl esters of ibuprofenic and mefenamic acids.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently associated with gastric mucosal and renal adverse reactions, related to inhibition of cyclooxygenase1 (Cox1) in tissues where prostaglandins exert physiological effects. This led us to develop a set of ibuprofenic acid and mefenamic acid esters, namely: 4-((4-substituted benzylidene)amino)phenyl 2-(4-isobutylphenyl)propanoate and 4-((4-substituted benzylidene)amino)phenyl 2-((2,4-dimethylphenyl)amino)benzoate analogs, which were synthesized by condensation of the corresponding acids with Schiff's bases [4-(4-substituted benzylideneamino)phenols] involving dicyclohexyl carbodiimmide (DCC) as mild dehydrating agent. The main objective is to reduce the GIT toxicity associated with acute and chronic NSAIDs use. Anti-inflammatory, analgesic as well as ulcerogenic activities of the prepared esters were evaluated in vivo and compared with that of ibuprofen as reference standard in all screenings, involving the carrageenan induced paw oedema model and hot plate method. Most of the synthesized esters showed remarkable analgesic and anti-inflammatory activities. Interestingly, all of the compounds were found to be non-ulcerogenic under the tested conditions. This evidence have suggested that modification of the carboxyl function of representative NSAIDs results in retained or enhanced anti-inflammatory and analgesic activities with reduced ulcerogenic potential. Additionally, a comparative AutoDock study into Cox 1 and Cox2 has been done involving both of rigid and flexible docking for potential selectivity of our compounds within different Cox enzymes and to find out the binding orientation of these novel esters into their binding site. Some of the newly prepared aforementioned compounds showed considerable more Cox2 over Cox1 binding affinities by flexible docking better than rigid one.

In-use stability assessment of FDA approved metformin immediate release and extended release products for N-Nitrosodimethylamine and dissolution quality attributes.

Metformin is a widely used first-line oral antidiabetic agent. TheFood and Drug Administration (FDA) confirmed the presence of the ofN-nitrosodimethylamine (NDMA) impurity, a carcinogenic, above the acceptable daily intake (ADI, 96 ng/day) in certain metformin products. The objective of the present study was to assess in-use stability of commercial metformin products for NDMA and dissolution quality attributes. Four immediate-release (M1-M4) and six extended-rerelease (M5-M10) metformin products were evaluated in the stability testing. All products were repacked in pharmacy vials and stored at 30 °C/75% RH for 12 weeks. Five products (M2, M3, M5, M7 and M10) had NDMA level above ADI limit (96 ng/day) before in-use stability exposure. NDMA in M2 (1164 ± 52.9 ng/tablet) and M3 (3776 ± 351.9 ng/tablet) products were 12 and 39 folds of ADI, respectively. Similarly, ER products, M5 (191 ± 94.1 ng/tablet), M7 (1473 ± 47.3 ng/tablet) and M10 (423 ± 55.8 ng/tablet) exhibited NDMA of 1.9, 15.3 and 4.4 folds of ADI, respectively. The impurity level significantly (p < 0.05) increased after 12-week stability exposure to 2.72, 2.47, 2.23 and 2.78 folds of initial values in M2, M3, M7 and M10. In summary, these findings suggested that carcinogenic impurity generation was affected by in-use stability condition exposure and it is expected that several more products currently in the market may also be recalled soon.

In-Situ Implant Formulation of Laurate and Myristate Prodrugs of Dolutegravir for Ultra-Long Delivery.

The focus of present work was to synthesize prodrugs of dolutegravir (DTG) for ultra-long delivery purpose. The prodrug was synthesized by esterification of hydroxyl group with carboxyl group of fatty acid (lauric or myristic acid). The prodrugs were characterized by differential scanning calorimetry, X-ray powder diffraction, nuclear magnetic resonance, Fourier transformed infrared, near infrared-chemical imaging, pH-solubility, partition coefficient, and stability (solid and liquid). Stability studies were performed by exposing the powder drugs to 40°C/75% RH for three months and buffer solutions at room temperature for 72 h. The prodrugs and drug were formulated into in-situ implant using biodegradable polymer. Thermal, spectral, and diffractometric data indicated formation of new chemical and solid forms. Formation of prodrugs resulted in lowering of melting point of DTG from 191.1°C to 163.7 and 140.7°C for DTG-Laurate and DTG-Myristate prodrugs, respectively. A decrease in solubility of 18.2-115.9 and 124.5-1594.9 folds was observed for DTG-Laurate and DTG-Myristate, respectively compared to DTG. Similarly, the prodrugs were highly lipophilic compared to DTG. Solid-state and pH-stability profiles of DTG and prodrugs were comparable. Implant formulation released 60.1% in 77 days compared to 95.6% in 35 days in the case of DTG-Myristate and DTG, respectively. In summary, combining prodrug and drug delivery approaches can be utilized for delivering drug for ultra-long period.

Design and Synthesis of 4-O-Podophyllotoxin Sulfamate Derivatives as Potential Cytotoxic Agents.

4-O-Podophyllotoxin sulfamate derivatives were prepared using the natural lignan podophyllotoxin. The prepared compounds were afforded by reacting O-sulfonyl chloride podophyllotoxin with ammonia or aminoaryl/heteroaryl motif. Biological evaluation was performed in human breast cancer (MCF7), ovarian cancer (A2780), colon adenocarcinoma (HT29), and normal lung fibroblast (MRC5) cell lines. Compound 3 exhibited potent inhibitory activity and good selectivity margin. Compounds 2, 3, and 7 exerted apoptotic effect in MCF7 cells in a dose-dependent manner. The cytotoxicity of the verified compounds was inferior to that of podophyllotoxin.

A comparative study of AutoDock and PMF scoring performances, and SAR of 2-substituted pyrazolotriazolopyrimidines and 4-substituted pyrazolopyrimidines as potent xanthine oxidase inhibitors.

4-Alkylidenehydrazino-1H-pyrazolo[3,4-d]pyrimidines, 4-arylmethylidenehydrazino-1H-pyrazolo[3,4-d]pyrimidines, and 2-substituted 7H-pyrazolo[4,3-e]-1,2,4-triazolo-[1,5-c]-pyrimidines as potential xanthine oxidase inhibitors were docked into the active site of the bovine milk xanthine dehydrogenase using two scoring functions involved in AutoDock 3.05 and the CAChe 6.1.10. The correlation coefficiency obtained between the AutoDock binding energy and IC(50) of the inhibitors was better than that obtained by the CAChe-PMF docking score. Many ligands exhibited one to four hydrogen bonds within the active site, where the detected hydrogen bonds by CAChe was identified quantitatively in the docked conformation by using MOPAC 2002. These ligands were docked into a long, narrow channel of the enzyme leading to the molybdopterin active moiety, with hydrogen bonding and electrostatic interaction between the planar aromatic moiety of the ligand and the enzyme. Furthermore, SAR among inhibitors was investigated, which revealed that the oxo group of pyrazolopyrimidine analogs is essential for its activity and the tricyclic derivatives are shown to be more potent than bicyclic ones. The mode of interaction of the docked inhibitors was described in details.

Dual Targeting of VEGFR2 and C-Met Kinases via the Design and Synthesis of Substituted 3-(Triazolo-thiadiazin-3-yl)indolin-2-one Derivatives as Angiogenesis Inhibitors.

The vascular endothelial growth factor receptor 2 (VEGFR2) and c-mesenchymal epithelial transition factor (c-Met) are members of receptor tyrosine kinases which have a crucial role in the process of angiogenesis. Isatin moiety is a versatile group that is shared in many compounds targeting both c-Met and VEGFR2 kinases. In this study, we designed and synthesized different derivatives of substituted 3-(triazolo-thiadiazin-3-yl)indolin-2-one derivatives (6a-y) as dual inhibitors for c-Met and VEGFR2 enzymes. Eight compounds 6a, 6b, 6e, 6l, 6n, 6r, 6v, and 6y were assessed for their anticancer activities against a panel of 58 cancer cell lines according to the US-NCI protocol. Compound 6b revealed the most effective antiproliferative potency (GI %), with broad-spectrum activity against different subpanels of the most NCI 58 tumor cell lines. An in vivo hen's egg-chorioallantoic membrane (HET-CAM) angiogenic study was carried out for 21 compounds 6a, b, d, f, h, i, k-o, t, and 6x to check their mortality and toxicity. At 100 µM concentration, all compounds produced 100% mortality of the chick embryos. At 40 µM concentration, 13 compounds did not exhibit any detectable mortality (nontoxic) and revealed a potent antiangiogenic effect. Seven compounds 6b, 6d, 6f, 6n, 6o, 6t, and 6x significantly decreased the number of blood vessels, and compound 6b was the most effective antiangiogenic agent comparable to dexamethasone. Molecular docking studies were conducted for compound 6b to investigate its mode of interaction within the binding site of both c-Met and VEGFR2 kinases.

Exosomes are the Driving Force in Preparing the Soil for the Metastatic Seeds: Lessons from the Prostate Cancer.

Exosomes are nano-membrane vesicles that various cell types secrete during physiological and pathophysiological conditions. By shuttling bioactive molecules such as nucleic acids, proteins, and lipids to target cells, exosomes serve as key regulators for multiple cellular processes, including cancer metastasis. Recently, microvesicles have emerged as a challenge in the treatment of prostate cancer (PCa), encountered either when the number of vesicles increases or when the vesicles move into circulation, potentially with an ability to induce drug resistance, angiogenesis, and metastasis. Notably, the exosomal cargo can induce the desmoplastic response of PCa-associated cells in a tumor microenvironment (TME) to promote PCa metastasis. However, the crosstalk between PCa-derived exosomes and the TME remains only partially understood. In this review, we provide new insights into the metabolic and molecular signatures of PCa-associated exosomes in reprogramming the TME, and the subsequent promotion of aggressive phenotypes of PCa cells. Elucidating the molecular mechanisms of TME reprogramming by exosomes draws more practical and universal conclusions for the development of new therapeutic interventions when considering TME in the treatment of PCa patients.

Exosomes-Mediated Transfer of Itga2 Promotes Migration and Invasion of Prostate Cancer Cells by Inducing Epithelial-Mesenchymal Transition.

Although integrin alpha 2 subunit (ITGA2) mediates cancer progression and metastasis, its transfer by exosomes has not been investigated in prostate cancer (PCa). We aimed to determine the role of exosomal ITGA2 derived from castration-resistant PCa (CRPC) cells in promoting aggressive phenotypes in androgen receptor (AR)-positive cells. Exosomes were co-incubated with recipient cells and tested for different cellular assays. ITGA2 was enriched in exosomes derived from CRPC cells. Co-culture of AR-positive cells with CRPC-derived exosomes increased their proliferation, migration, and invasion by promoting epithelial-mesenchymal transition, which was reversed via ITGA2 knockdown or inhibition of exosomal uptake by methyl-ß-cyclodextrin (MßCD). Ectopic expression of ITGA2 reproduced the effect of exosomal ITGA2 in PCa cells. ITGA2 transferred by exosomes exerted its effect within a shorter time compared to that triggered by its endogenous expression. The difference of ITGA2 protein expression in localized tumors and those with lymph node metastatic tissues was indistinguishable. Nevertheless, its abundance was higher in circulating exosomes collected from PCa patients when compared with normal subjects. Our findings indicate the possible role of the exosomal-ITGA2 transfer in altering the phenotype of AR-positive cells towards more aggressive phenotype. Thus, interfering with exosomal cargo transfer may inhibit the development of aggressive phenotype in PCa cells.

HER2 Kinase-Targeted Breast Cancer Therapy: Design, Synthesis, and In Vitro and In Vivo Evaluation of Novel Lapatinib Congeners as Selective and Potent HER2 Inhibitors with Favorable Metabolic Stability.

HER2 kinase as a well-established target for breast cancer (BC) therapy is associated with aggressive clinical outcomes; thus, herein we present structural optimization for HER2-selective targeting. HER2 profiling of the developed derivatives demonstrated potent and selective inhibitions (IC50: 5.4-12 nM) compared to lapatinib (IC50: 95.5 nM). Favorably, 17d exhibited minimum off-target kinase activation. NCI-5-dose screening revealed broad-spectrum activities (GI50: 1.43-2.09 µM) and 17d had a remarkable selectivity toward BC. Our compounds revealed significant selective and potent antiproliferative activities (∼20-fold) against HER2+ (AU565, BT474) compared to HER2(-) cells. At 0.1 IC50, 15i, 17d, and 25b inhibited pERK1/2 and pAkt by immunoblotting. Furthermore, 17d demonstrated potent in vivo tumor regression against the BT474 xenograft model. Notably, a metastasis case was observed in the vehicle but not in the test mice groups. CD-1 mice metabolic stability assay revealed high stability and low intrinsic clearance of 17d (T1/2 > 145 min and CLint(mic) < 9.6 mL/min/kg).

Targeting CDC7 sensitizes resistance melanoma cells to BRAFV600E-specific inhibitor by blocking the CDC7/MCM2-7 pathway.

Although the utilization of selective BRAFV600E inhibitors is associated with improved overall survival in patients with metastatic melanoma, a growing challenge of drug resistance has  emerged. CDC7 has been shown to be overexpressed and associated with poor prognosis in various cancers including melanoma. Thus, we aimed to elucidate the biological role of CDC7 in promoting Vemurafenib resistance and the anticipated benefits of dual targeting of BRAFV600E and CDC7 in melanoma cells. We performed exosomes-associated microRNA profiling and functional assays to determine the role of CDC7 in drug resistance using Vemurafenib-sensitive and resistant melanoma cells. Our results demonstrated that Vemurafenib-resistant cells exhibited a persistent expression of CDC7 in addition to prolonged activity of MCM2 compared to drug-sensitive cells. Reconstitution of miR-3613-3p in resistant cells downregulated CDC7 expression and reduced the number of colonies. Treatment of cells with low concentrations of CDC7 inhibitor TAK-931 sensitized resistant cells to Vemurafenib and reduced the number of cell colonies. Taken together, CDC7 overexpression and downregulation of miR-3613-3p were associated with Vemurafenib resistance in BRAFV600E- bearing melanoma cells. Dual targeting of CDC7 and BRAFV600E reduced the development of resistance against Vemurafenib. Further studies are warranted to investigate the clinical effect of targeting CDC7 in metastatic melanoma.