Shielding against breast tumor relapse with an autologous chemo-photo-immune active Nano-Micro-Sera based fibrin implant.

Local recurrence post-surgery in early-stage triple-negative breast cancer is a major challenge. To control the regrowth of a residual tumor, we have developed an autologous therapeutic hybrid fibrin glue for intra-operative implantation. Using autologous serum proteins as stabilizers, we have optimized high drug-loaded lapatinib-NanoSera (Lap-NS; ∼66% L.C.) and imiquimod-MicroSera (IMQ-MS; ∼92% L.C). Additionally, plasmonic nanosera (PNS) with an ∼67% photothermal conversion efficiency under 980 nm laser irradiation was also developed. While localized monotherapy with either Lap-NS or PNS reduced the tumor regrowth rate, their combination with IMQ-MS amplified the effect of immunogenic cell death with a high level of tumor infiltration by immune cells at the surgical site. The localized combination immunotherapy with a Nano-MicroSera based hybrid fibrin implant showed superior tumor inhibition and survival with significant promise for clinical translation.

Tocopherol-human serum albumin nanoparticles enhance lapatinib delivery and overcome doxorubicin resistance in breast cancer.

Introduction: HER2, a tyrosine kinase receptor, is amplified in HER2-positive breast cancer, driving cell signaling and growth. Aim: This study aimed to combat multidrug resistance in Dox-insensitive breast adenocarcinoma by creating a nanoformulation therapy with a tyrosine kinase inhibitor. Methodology: Human serum albumin (HSA) was conjugated with α-D-tocopherol succinate to form nanoaggregates loaded with lapatinib (Lapa). Results: The resulting Lapa@HSA(VE) NPs were 117.2 nm in size and demonstrated IC50 values of 10.25 µg/ml on MCF7 (S) and 8.02 µg/ml on MCF7 (R) cell lines. Conclusion: Lapa@HSA(VE) NPs showed no hepatotoxicity, unlike free Lapa, as seen in acute toxicity studies in rats.

[Box: see text].

A Lipophilic Salt Form to Enhance the Lipid Solubility and Certain Biopharmaceutical Properties of Lapatinib.

Lapatinib (LTP) commercially available as lapatinib ditosylate (LTP-DTS) salt is the only drug approved for the treatment of HER-positive metastatic breast cancer. A low and pH-dependent solubility results in poor and variable oral bioavailability, thus driving significant interest in molecular modification and formulation strategies of the drug. Furthermore, due to very high crystallinity, LTP and LTP-DTS have low solubility in lipid excipients, making it difficult to be delivered by lipid-based carrier systems. Thus, the present work reports a new salt form of LTP with a docusate counterion to enhance the pharmaceutical properties of the drug (LTP-DOC). NMR spectra showed a downfield shift of the methylene singlet proton from 3.83 and 4.41 ppm, indicating a lowering of electron density on the adjacent nitrogen atom and confirming the formation of amine-sulfonyl salt through the specified basic nitrogen center located adjacent to the furan ring. PXRD diffractograms of LTP-DOC indicated a reduced crystallinity of the prepared salt. The dissolution, equilibrium solubility, lipid excipient solubility, partitioning coefficient, distribution coefficient, tabletability, and in vitro cytotoxicity of the lipophilic salt of LTP were investigated. The equilibrium solubility data showed that LTP-DOC possesses a pH-independent solubility profile in the pH range of 3.5 to 7.4 with a 3.14 times higher permeability coefficient than commercial ditosylate salt. Furthermore, the prepared LTP-DOC salts showed twice higher log P than the free base and 8 times higher than LTP-DTS. The prepared LTP-DOC was found to have 4- to 9-fold higher solubility in lipid excipients like Capmul MCM C8 and Maisine CC compared to the ditosylate salt. The LTP-DOC salt was tabletable and showed approximately 1.2 times lower dissolution than commercial ditosylate salt, indicating extended-release behavior. A cytotoxicity study of LTP-DOC salt showed an approximately 2.5 times lower IC50 value than the LTP-free base and 1.7 times lower than commercial ditosylate salt with an approximately 3 times higher selectivity index. The investigations strongly indicate a high translational potential of the prepared salt form in maintaining solubility-lipophilicity interplay, enhancing the drug's bioavailability, and developing lipidic formulations.

pH-responsive drug-loaded peptides enhance drug accumulation and promote apoptosis in tumor cells.

The efficacy of chemotherapeutic drugs in tumor treatment is limited by their toxicity and side effects due to their inability to selectively accumulate in tumor tissue. In addition, chemotherapeutic agents are easily pumped out of tumor cells, resulting in their inadequate accumulation. To overcome these challenges, a drug delivery system utilizing the amphiphilic peptide Pep1 was designed. Pep1 can self-assemble into spherical nanoparticles (PL/Pep1) and encapsulate paclitaxel (PTX) and lapatinib (LAP). PL/Pep1 transformed into nanofibers in an acidic environment, resulting in longer drug retention and higher drug concentrations within tumor cells. Ultimately, PL/Pep1 inhibited tumor angiogenesis and enhanced tumor cell apoptosis. The use of shape-changing peptides as drug carriers to enhance cancer cell apoptosis is promising.

A pH-sensitive T7 peptide-decorated liposome system for HER2 inhibitor extracellular delivery: an application for the efficient suppression of HER2+ breast cancer.

HER2+ breast cancer is highly aggressive and proliferative even after multiple chemotherapy regimens. At present, the available clinical treatment duration of chemotherapeutic agents is limited by severe toxicity to noncancerous tissues, which are attributed to insufficient targeting. Here, we designed an active-targeted and pH-responsive liposome to improve the treatment. The ideas were as follows: (1) using liposome as a nano-delivery system for HER2 inhibitor (lapatinib; LAP) to reduce the toxicity; (2) modifying the capsule with T7 peptide for specific targeted delivery to the tumor cells, and (3) enabling the capsule with the pH-sensitive ability and triggering sustained drug release at extracellular weakly acidic microenvironment to emerge toxicity in tumors and to improve curative effects. It was found that T7 peptide-modified pH-sensitive liposome (T7-LP) was more effective and safer than free drug and unmodified liposome, and reduced drug-induced side effects and noncancerous toxicity. These results support the application potential of T7-LP in improving the efficacy of LAP in HER2+ breast cancer treatment. It might be a novel LAP formulation as a clinical agent.

Conjugates Derived from Lapatinib Derivatives with Cancer Cell Stemness Inhibitors Effectively Reversed Drug Resistance in Triple-Negative Breast Cancer.

Increasing evidence indicates that the cancer stem cell (CSC) subpopulation contributes to the therapeutic resistance and metastasis of tumors, leading to patient recurrence and death. Herein, we designed and synthesized several compounds by conjugating lapatinib derivatives with different CSC inhibitors to treat with lapatinib-induced MDA-MB-231 drug-resistant cells. In vitro biological studies indicated that 3a showed strong cytotoxicity and EGFR enzyme inhibitory activity and effectively reversed lapatinib-mediated resistance of MDA-MB-231 cells via inhibiting triple-negative breast cancer (TNBC) cell stemness and the AKT/ERK signaling pathway. In addition, 3a was capable of strongly suppressing the invasion and migration of TNBC cells by inhibiting the Wnt/ß-catenin signaling pathway and MMP-2 and MMP-9 protein expression. In vivo tumorigenicity tests showed that 3a could inhibit the occurrence of TNBC by inhibiting BCSCs, proving 3a is a potential EGFR and CSC dual inhibitor for TNBC treatment.

Molecular recognition of tak-285 and lapatinib by inactive, active, and middle active-inactive HER2.

Experimental and theoretical studies have provided structural information regarding the shift from inactive to active EGFR, throughout which both conformations are linked via binding to specific tyrosine kinase inhibitors. For HER2, an intermediate active-inactive receptor conformation is present in the PDB, which has been co-crystallized with tak-285. The affinity of HER2 in monomeric state to tak-285 has been previously reported. However, the lack of structural knowledge of HER2 limits our capacity to understand whether tak-285, or other known HER2 inhibitors, selectively bind active, inactive, or intermediate forms of HER2. To elucidate mechanisms by which tak-285 binds to HER2, we first obtained information regarding the structural features of the active state of HER2 via microsecond MD simulations from the crystallized intermediate structure previously determined. Based on these HER2 conformers, together with the inactive HER2 conformer obtained in a previous study, we used docking and MD simulations coupled to MMGBSA approach to assess binding of tak-285 and lapatinib, known HER2/EGFR dual inhibitors, to HER2. Structural and energetic studies revealed that tak-285 binds with a greater affinity than lapatinib to active and intermediate active-inactive forms of HER2. This is in accordance with experimental findings that showed the tak-285 inhibitor has increased activity relative to lapatinib in breast cancer cell lines.

Development of a Pediatric Mini-Tablet Formulation for Expedited Preclinical Studies.

Multiple considerations are essential to address the main challenges of dose flexibility and patient adherence in pediatric drug development, particularly for oncology. Mini-tablets, 2 mm in diameter, were manufactured using a rotary tablet press at a set weight and compression force level. The physical characteristics were consistent for mini-tablets throughout multiple batches. Polymeric amorphous solid dispersion (ASD) was used as a solubility enhancing technique to increase solubility and exposure of lapatinib. The effects of the polymeric excipient and disintegrant on drug release properties were investigated. While having a lower apparent solubility and shorter storage stability, hydroxypropyl methylcellulose E3 (HPMCE3) formulation provided a higher percentage of drug release compared to hydroxypropyl methylcellulose phthalate (HPMCP). The intermolecular interaction within the ASD system plays a role in the level of apparent solubility, physical stability, and concentration of free drug available in an aqueous environment. Juvenile porcine models at two different weight groups (10 and 20 kg) were used to obtain the pharmacokinetic parameters of lapatinib. While the dose-normalized exposure of drug was found to be lower in the pig study, the dose flexibility of mini-tablets enabled a constant dose level to be administered to achieve equivalent plasma concentration-time profiles between the two groups. This linear scaling in the amount of drug in pediatric and adult population has also been observed in human clinical studies.

Recent Advances on Epidermal Growth Factor Receptor as a Molecular Target for Breast Cancer Therapeutics.

Epidermal Growth Factor Receptor (EGFR), a type-I transmembrane protein with intrinsic tyrosine kinase activity, is activated by peptide growth factors such as EGF, epigen, amphiregulin, etc. EGFR plays a vital role in regulating cell growth, migration, and differentiation in various tissue-specific cancers. It has been reported to be overexpressed in lung, head, and neck, colon, brain, pancreatic, and breast cancer that triggers tumor progression and drug resistance. EGFR overexpression alters the signaling pathway and induces cell division, invasion, and cell survival. Our prior studies demonstrated that EGFR inhibition modulates chemosensitivity in breast cancer stem cells, thereby serving as a potential drug target for breast cancer mitigation. Tyrosine kinase inhibitors (Lapatinib, Neratinib) and monoclonal antibodies (Trastuzumab) targeting EGFR have been developed and approved by the US FDA for clinical use against breast cancer. This review highlights the critical role of EGFR in breast cancer progression and enumerates the various approaches being undertaken to inhibit aggressive breast cancers by suppressing the downstream pathways. Furthermore, the mechanisms of action of potential molecules at various stages of drug development, as well as clinically approved drugs for breast cancer treatment, are illustrated.

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).

Reversing P-Glycoprotein-Associated Multidrug Resistance of Breast Cancer by Targeted Acid-Cleavable Polysaccharide Nanoparticles with Lapatinib Sensitization.

For reversing the treatment failure in P-glycoprotein (P-gp)-associated MDR (multidrug resistance) of breast cancer, a high dose of Lapatinib (Lap), a substrate of breast cancer-resistant protein, was encapsulated into safe and effective acid-cleavable polysaccharide-doxorubicin (Dox) conjugates to form targeted HPP-Dox/Lap nanoparticles with an optimal drug ratio and appropriate nanosize decorated with oligomeric hyaluronic acid (HA) for specially targeting overexpressed CD44 receptors of MCF-7/ADR. The markedly increased cellular uptake and the strongest synergetic cytotoxicity revealed the enhanced reversal efficiency of HPP-Dox/Lap nanoparticles with reversal multiples at 29.83. This was also verified by the enhanced penetrating capacity in multicellular tumor spheroids. The reinforced Dox retention and substantial down-regulation of P-gp expression implied the possible mechanism of MDR reversal. Furthermore, the efficient ex vivo accumulation and distribution of nanoparticles in the tumor site and the high tumor growth inhibition (93%) even at a lower dosage (1 mg/kg) as well as lung metastasis inhibition in vivo with negligible side effects revealed the overwhelming advantages of targeted polysaccharide nanoparticles and Lap-sensitizing effect against drug-resistant tumor. The development of an efficient and nontoxic-targeted polysaccharide delivery system for reversing MDR by synergistic therapy might provide a potential clinical application value.

Evaluation of aminolevulinic acid-mediated protoporphyrin IX fluorescence and enhancement by ABCG2 inhibitors in renal cell carcinoma cells.

Aminolevulinic acid (ALA) has been approved as an intraoperative molecular imaging probe for protoporphyrin IX (PpIX) fluorescence-guided resection of glioma. Here we explored its potential application for renal cell carcinoma (RCC) that is showing increased incidence in recent years. ALA-mediated PpIX in cell lysates (intracellular) and culture medium was measured in five human RCC cell lines (786-O, 769-P, A-704, Caki-1, Caki-2) and a non-tumor human kidney epithelial cell line HK-2 by spectrofluorometry and flow cytometry. The activity of PpIX bioconversion enzyme ferrochelatase (FECH) and PpIX efflux transporter ABCG2 was determined to correlate with the PpIX level. We found that ALA-PpIX fluorescence was highly variable among RCC cell lines and A-704 was the only RCC cell line exhibiting significantly higher intracellular PpIX than HK-2 cells. Neither the intracellular PpIX level nor the total amount of PpIX (including PpIX in cell lysates and the medium) had significant correlation with the activity of FECH or ABCG2. To enhance the intracellular PpIX, cells were treated with Ko143, a pharmacological inhibitor of ABCG2. Ko143 significantly increased the intracellular PpIX in cell lines with ABCG2 activity, but not in cell lines with little ABCG2 activity. In fact, there was a positive correlation between the ABCG2 activity and Ko143-induced PpIX enhancement across kidney cell lines. To identify clinically relevant ABCG2 inhibitors, small molecule inhibitors targeting various cell signaling pathways, some of which are known to inhibit ABCG2, were evaluated for the enhancement of ALA-PpIX in Caki-2 cells that had the highest ABCG2 activity in the RCC cell panel. Our screening led to the identification of several clinically available inhibitors that significantly increased the intracellular PpIX. Particularly, kinase inhibitor lapatinib exhibited the strongest enhancement effect. These clinical inhibitors can be used for the enhancement of ALA-PpIX fluorescence in tumors with elevated ABCG2 activity.

Imidazolium-based ionic liquid functionalized mesoporous silica nanoparticles as a promising nano-carrier: response surface strategy to investigate and optimize loading and release process for Lapatinib delivery.

Imidazolium-based ionic liquid functionalized PEGylated mesoporous silica nanoparticles MCM-41 (denoted as [ImIL-PEGylated@MCM-41] NPs) is synthesized and evaluated as an efficient and reliable pH-sensitive nano-carrier for controlled release of cationic Lapatinib (Lap) drug. This nano-DDS was fully characterized by dynamic light scattering, scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, N2 adsorption-desorption measurement, and differential scanning calorimeter. Furthermore, the drug loading content and in-vitro drug release profile were studied. The entrapment and loading efficiency of the optimized formulation for Lap were 91 ± 2.0% and 32.21 ± 2.70%, respectively. The results of cytotoxicity assay demonstrated that ImIL-PEG@MCM-41 has no significant toxicity on both cancerous and normal cell lines and the anticancer activity of Lap@ImIL-PEG@MCM-41 was comparable to free drug in case of human breast cells (SKBR3) and human embryonic kidney 293 cells (HEK-293). Meanwhile, three-dimensional (3D) cell culture was performed by multicellular tumor spheroids for understanding of cell response to drugs in physiologically 3D microenvironments. The results of Lap@ImIL-PEG@MCM-41 uptake during 48 hours showed a gradual release of the Lap through the multicellular tumor spheroids. This showed that the pH-responsive controlled release of Lapatinib leads to the satisfactory results in the in vitro breast cancer therapy.

Interaction of the small-molecule kinase inhibitors tofacitinib and lapatinib with membranes.

Lapatinib and tofacitinib are small-molecule kinase inhibitors approved for the treatment of advanced or metastatic breast cancer and rheumatoid arthritis, respectively. So far, the mechanisms which are responsible for their activities are not entirely understood. Here, we focus on the interaction of these drug molecules with phospholipid membranes, which has not yet been investigated before in molecular detail. Owing to their lipophilic characteristics, quantitatively reflected by large differences of the partition equilibrium between water and octanol phases (expressed by logP values), rather drastic differences in the membrane interaction of both molecules have to be expected. Applying experimental (nuclear magnetic resonance, fluorescence and ESR spectroscopy) and theoretical (molecular dynamics simulations) approaches, we found that lapatinib and tofacitinib bind to lipid membranes and insert into the lipid-water interface of the bilayer. For lapatinib, a deeper embedding into the membrane bilayer was observed than for tofacitinib implying different impacts of the molecules on the bilayer structure. While for tofacitinib, no influence to the membrane structure was found, lapatinib causes a membrane disturbance, as concluded from an increased permeability of the membrane for polar molecules. These data may contribute to a better understanding of the cellular uptake mechanism(s) and the side effects of the drugs.

Characterization of Locally Excited and Charge-Transfer States of the Anticancer Drug Lapatinib by Ultrafast Spectroscopy and Computational Studies.

Lapatinib (LAP) is an anticancer drug, which is metabolized to the N- and O-dealkylated products (N-LAP and O-LAP, respectively). In view of the photosensitizing potential of related drugs, a complete experimental and theoretical study has been performed on LAP, N-LAP and O-LAP, both in solution and upon complexation with human serum albumin (HSA). In organic solvents, coplanar locally excited (LE) emissive states are generated; they rapidly evolve towards twisted intramolecular charge-transfer (ICT) states. By contrast, within HSA only LE states are detected. Accordingly, femtosecond transient absorption reveals a very fast switching (ca. 2 ps) from LE (λmax =550 nm) to ICT states (λmax =480 nm) in solution, whereas within HSA the LE species become stabilized and live much longer (up to the ns scale). Interestingly, molecular dynamics simulation studies confirm that the coplanar orientation is preferred for LAP (or to a lesser extent N-LAP) within HSA, explaining the experimental results.

Closo-Carboranyl- and Metallacarboranyl [1,2,3]triazolyl-Decorated Lapatinib-Scaffold for Cancer Therapy Combining Tyrosine Kinase Inhibition and Boron Neutron Capture Therapy.

One of the driving forces of carcinogenesis in humans is the aberrant activation of receptors; consequently, one of the most promising mechanisms for cancer treatment is receptor inhibition by chemotherapy. Although a variety of cancers are initially susceptible to chemotherapy, they eventually develop multi-drug resistance. Anti-tumor agents overcoming resistance and acting through two or more ways offer greater therapeutic benefits over single-mechanism entities. In this study, we report on a new family of bifunctional compounds that, offering the possibility of dual action (drug + radiotherapy combinations), may result in significant clinical benefits. This new family of compounds combines two fragments: the drug fragment is a lapatinib group, which inhibits the tyrosine kinase receptor activity, and an icosahedral boron cluster used as agents for neutron capture therapy (BNCT). The developed compounds were evaluated in vitro against different tyrosine kinase receptors (TKRs)-expressing tumoral cells, and in vitro-BNCT experiments were performed for two of the most promising hybrids, 19 and 22. We identified hybrid 19 with excellent selectivity to inhibit cell proliferation and ability to induce necrosis/apoptosis of glioblastoma U87 MG cell line. Furthermore, derivative 22, bearing a water-solubility-enhancing moiety, showed moderate inhibition of cell proliferation in both U87 MG and colorectal HT-29 cell lines. Additionally, the HT-29 cells accumulated adequate levels of boron after hybrids 19 and 22 incubations rendering, and after neutron irradiation, higher BNCT-effects than BPA. The attractive profile of developed hybrids makes them interesting agents for combined therapy.

Lapatinib, Nilotinib and Lomitapide Inhibit Haemozoin Formation in Malaria Parasites.

With the continued loss of antimalarials to resistance, drug repositioning may have a role in maximising efficiency and accelerating the discovery of new antimalarial drugs. Bayesian statistics was previously used as a tool to virtually screen USFDA approved drugs for predicted ß-haematin (synthetic haemozoin) inhibition and in vitro antimalarial activity. Here, we report the experimental evaluation of nine of the highest ranked drugs, confirming the accuracy of the model by showing an overall 93% hit rate. Lapatinib, nilotinib, and lomitapide showed the best activity for inhibition of ß-haematin formation and parasite growth and were found to inhibit haemozoin formation in the parasite, providing mechanistic insights into their mode of antimalarial action. We then screened the USFDA approved drugs for binding to the ß-haematin crystal, applying a docking method in order to evaluate its performance. The docking method correctly identified imatinib, lapatinib, nilotinib, and lomitapide. Experimental evaluation of 22 of the highest ranked purchasable drugs showed a 24% hit rate. Lapatinib and nilotinib were chosen as templates for shape and electrostatic similarity screening for lead hopping using the in-stock ChemDiv compound catalogue. The actives were novel structures worthy of future investigation. This study presents a comparison of different in silico methods to identify new haemozoin-inhibiting chemotherapeutic alternatives for malaria that proved to be useful in different ways when taking into consideration their strengths and limitations.

Metabolic Stability Assessment of New PARP Inhibitor Talazoparib Using Validated LC-MS/MS Methodology: In silico Metabolic Vulnerability and Toxicity Studies.

BACKGROUND: Talazoparib (BMN673) is a new poly(ADP-ribose) polymerase inhibitor that has been FDA approved for patients suffering from metastatic breast cancer with germline BRCA mutations. METHOD AND RESULTS: In the current study, an accurate and efficient liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytical methodology was developed for TZB estimation in addition to its metabolic stability assessment. TZB and lapatinib (LAP) (which is chosen as an internal standard; IS) were separated using reversed phase elution system (Hypersil C18 column) with an isocratic mobile phase. The linearity range of the established method was 5-500 ng/mL (r2 ≥ 0.999) in the human liver microsomes (HLMs) matrix. Different parameters were calculated to confirm the method sensitivity (limit of quantification was 2.0 ng/mL), and reproducibility (intra- and inter-day precision and accuracy were below 3.1%) of our methodology. For evaluation of TZB metabolic stability in HLM matrix, intrinsic clearance (9.59 µL/min/mg) and in vitro half-life (72.7 mins) were calculated. TZB treatment discontinuations were reported due to adverse events and dose accumulation, so in silico metabolic vulnerability (experimental and in silico) and toxicity assessment (in silico) of TZB were performed utilizing P450 Metabolism and DEREK modules of StarDrop software. CONCLUSION: TZB is slowly metabolized by the liver. TZB was reported to be minimally metabolized by the liver that approved our outcomes. We do recommend that plasma levels be monitored in cases when talazoparib is used for a long period of time, since it is possible for TZB to bioaccumulate after multiple doses to toxic levels. According to our knowledge, the current method is considered the first LC-MS/MS methodology for evaluating TZB metabolic stability. Further drug discovery studies can be done depending on this concept allowing the designing of new series of compounds with more safety profile through reducing side effects and improving metabolic behavior.

Dissecting the molecular recognition of dual lapatinib derivatives for EGFR/HER2.

Abnormalities in the expression levels of EGFR/HER2 are found in many different types of human cancer; therefore, the design of dual inhibitors of EGFR/HER2 is a recognized anti-cancer strategy. Some lapatinib derivatives have been previously synthesized by modification at the methylsulfonylethylaminomethylfuryl group and biologically evaluated, demonstrating that the 2i compound shows potent inhibitory activity against EGFR/HER2-overexpressing cancer cells. In the present study, we explored the structural and energetic features that guide the molecular recognition of 2i using various EGFR/HER2 states. Molecular dynamics (MD) simulation with an MMPB(GB)SA approach was used to generate the inactive EGFR/HER2-ligand complexes. Our results corroborate that slight modification of lapatinib contributes to an increase in the affinity of the 2i compound for inactive EGFR/HER2 as compared with lapatinib compound, which is in accordance with experimental results. Comparison with previous results reveals that lapatinib and its derivative bind more strongly to the inactive than the intermediate active-inactive HER2 state. Principal component analysis allowed the observation that coupling of 2i to EGFR/HER2 is linked to a reduction in the conformational mobility, which may also contribute to the improvement in affinity observed for this compound as compared with lapatinib.

Comparative anti-proliferative effects of potential HER2 inhibitors on a panel of breast cancer cell lines.

BACKGROUND: Breast cancer is one of the most lethal types of cancer in women worldwide. The human epidermal growth factor receptor 2 (HER2) is considered as a validated target in breast cancer therapy. Previously, we have used quantitative structure activity relationship QSAR equations and their associated pharmacophore models to screen for new promising HER2 structurally diverse inhibitory leads which were tested against HER2-overexpressing SKOV3 ovarian cancer cell line. OBJECTIVE: In this study, we sought to explore the effect of most active ligands against different normal and breast cancer cell lines that represent different breast cancer subtypes with distinguished expression levels in HER2 and HER1. METHODS: We have tested the promising compounds against SKBR3, MDA-MB-231, MCF7, human fibroblast, and MCF10 cell lines. To understand the inhibitory effects of the active ligands against HER2 over expressed breast cancer cell lines, all inhibitors and the control compound, lapatinib, were docked into the active site of HER2 enzyme performed using Ligand Fit docking engine and PMF scoring function. RESULTS: Five ligands exhibited promising results with relatively low IC50 values on cells that amplify HER2 and high IC50 on those that do not express such a receptor. The most potent compound (compound 13) showed an IC50 of 0.046 µM. To test their toxicity against normal cells, the active compounds were tested against both normal fibroblast and normal breast cancer cell MCF-10 and relatively high IC50 values were scored. The IC50 values on HER2 over-expressed breast cancer and normal fibroblast cells provided a promising safety index. Docking results showed the highest similarity in the binding site between the most active ligand and the lapatinib. CONCLUSION: Our pharmacophore model resulted in a high potent ligand that shows high potency against HER2 positive breast cancer and relatively low toxicity towards the normal human cells.