The epidermal growth factor receptor-tyrosine kinase: a promising therapeutic target in solid tumors

Ensartinib for EML4-ALK-positive lung adenocarcinoma with comorbid mutations in TP53, EGFR, and ERBB2: a case report

Background

In non-small cell lung cancer (NSCLC), anaplastic lymphoma kinase (ALK) gene rearrangements are commonly detected in lung adenocarcinoma. ALK-positive (ALK+) patients may occasionally exhibit concurrent genetic alterations that potentially impact prognosis. New therapeutic strategies are needed for ALK+ NSCLC patients with multiple simultaneous gene mutations.

Case presentation

A 58-year-old man was diagnosed with lung adenocarcinoma (stage IVB, T4N3M1c) with an echinoderm microtubule-associated protein-like 4-ALK+ (EML4-ALK+) rearrangement, harboring tumor protein 53 (TP53), epidermal growth factor receptor (EGFR), and receptor tyrosine-protein kinase erbB-2 (ERBB2) mutations. After three cycles of chemotherapy, the patient developed intolerance. Subsequently, ensartinib (225 mg daily) was administered orally on April 14, 2021. After 3 months of ensartinib treatment, the patient achieved a partial response and reached stable disease at six months, which sustained for 30 months till April 8, 2024, with grade 1 rash and no brain metastases. Currently, the patient remains on ensartinib treatment, without disease progression.

Conclusion

This case demonstrates the potential for ensartinib in the treatment of EML4-ALK+ lung adenocarcinoma with multiple gene mutations. Further investigation through clinical trials is needed to evaluate the safety and efficacy of this targeted therapy.

Unraveling the mechanism of microRNA-134 in colon cancer progression: Targeting KRAS and PIK3CA for cell cycle control and histone deacetylase regulation

Colon cancer is the leading cause of cancer-related deaths worldwide. MicroRNAs (miRNAs) are key regulators of gene expression, often dysregulated in colon cancer. This study aims to elucidate the therapeutic role of miR-134-5p as a tumor suppressor miRNA in colon cancer cells. We analyzed miRNA expression profiles in primary and metastatic colon cancer cells. The clinical significance of miR-134-5p was evaluated using the TCGA database. Bioinformatics tools (HADDOCK) predicted miRNA-mRNA interactions and the molecular docking of miRNA-mRNA-AGO2 complexes. Luciferase reporter assays, cell proliferation, immunofluorescence, colony forming unit assays, and qRT-PCR analysis assessed miR-134-5p effects on KRAS, PIK3CA, and downstream signaling pathways in primary and metastatic colon cancer cells. miR-134-5p was downregulated in colon cancer cells. Bioinformatics analysis suggested KRAS, PIK3CA, EGFR, and HDAC5 as potential targets. HADDOCK analysis revealed strong binding affinity and structural stability between KRAS, PIK3CA, miR-134-5p, and AGO2. Gene-reporter assays confirmed miR-134-5p-mediated degradation of KRAS and PIK3CA. miR-134-5p transfection reduced KRAS and PI3K protein levels, suppressed EGFR/RTK signaling and its downstream targets, and inhibited HDAC expression, ultimately reducing colon cancer cell proliferation. The results of this study confirm that miR-134-5p acts as a potential tumor suppressor miRNA in colon cancer cells by inhibiting KRAS and PI3K expression through AGO2-mediated gene silencing. It deregulates downstream EGFR signaling and HDACs, thereby reducing colon cancer cell proliferation. These findings highlight miR-134-5p as a promising therapeutic target for miRNA-mediated anticancer therapy.

Recent Developments in Nanotechnology and Immunotherapy for the Diagnosis and Treatment of Pancreatic Cancer

Pancreatic cancer kills millions of people worldwide each year and is one of the most prevalent causes of mortality that requires prompt therapy. A large number of people suffering from pancreatic cancer are detected at an advanced stage, with incurable and drug-resistant tumor, hence the overall survival rate of pancreatic cancer is less. The advance phase of this cancer is generated because of expression of the cancer-causing gene, inactivation of the tumorsuppressing gene, and deregulation of molecules in different cellular signalling pathways. The prompt diagnosis through the biomarkers significantly evades the progress and accelerates the survival rates. The overexpression of Mesothelin, Urokinase plasminogen activator, IGFR, Epidermal growth factor receptor, Plectin-1, Mucin-1 and Zinc transporter 4 were recognized in the diagnosis of pancreatic cancer. Nanotechnology has led to the development of nanocarriersbased formulations (lipid, polymer, inorganic, carbon based and advanced nanocarriers) which overcome the hurdles of conventional therapy, chemotherapy and radiotherapy which causes toxicity to adjacent healthy tissues. The biocompatibility, toxicity and large-scale manufacturing are the hurdles associated with the nanocarriers-based approaches. Currently, Immunotherapybased techniques emerged as an efficient therapeutic alternative for the prevention of cancer. Immunological checkpoint targeting techniques have demonstrated significant efficacy in human cancers. Recent advancements in checkpoint inhibitors, adoptive T cell therapies, and cancer vaccines have shown potential in overcoming the immune evasion mechanisms of pancreatic cancer cells. Combining these immunotherapeutic approaches with nanocarriers holds great promise in enhancing the antitumor response and improving patient survival.

Identification of novel c-Kit inhibitors from natural sources using virtual screening and molecular dynamics simulations

The Mast/Stem cell growth factor receptor Kit (c-Kit), a Proto-oncogene c-Kit, is a tyrosine-protein kinase involved in cell differentiation, proliferation, migration, and survival. Its role in developing certain cancers, particularly gastrointestinal stromal tumors (GISTs) and acute myeloid leukemia (AML), makes it an attractive therapeutic target. Several small molecule inhibitors targeting c-Kit have been developed and approved for clinical use. Recent studies have focused on identifying and optimizing natural compounds as c-Kit inhibitors employing virtual screening. Still, drug resistance, off-target side effects, and variability in patient response remain significant challenges. From this perspective, phytochemicals could be an important resource for discovering novel c-Kit inhibitors with less toxicity, improved efficacy, and high specificity. This study aimed to uncover possible c-Kit inhibitors by utilizing a structure-based virtual screening of active phytoconstituents from Indian medicinal plants. Through the screening stages, two promising candidates, Anilinonaphthalene and Licoflavonol, were chosen based on their drug-like features and ability to bind to c-Kit. These chosen candidates were subjected to all-atom molecular dynamics (MD) simulations to evaluate their stability and interaction with c-Kit. The selected compounds Anilinonaphthalene from Daucus carota and Licoflavonol from Glycyrrhiza glabra showed their potential to act as selective binding partners of c-Kit. Our results suggest that the identified phytoconstituents could serve as a starting point to develop novel c-Kit inhibitors for developing new and effective therapies against multiple cancers, including GISTs and AML. The use of virtual screening and MD simulations provides a rational approach to discovering potential drug candidates from natural sources.Communicated by Ramaswamy H. Sarma.

Leveraging Bulk and Single-Cell RNA Sequencing Data of NSCLC Tumor Microenvironment and Therapeutic Potential of NLOC-15A, A Novel Multi-Target Small Molecule

Lung cancer poses a serious threat to human health and has recently been tagged the most common malignant disease with the highest incidence and mortality rate. Although epidermal growth factor (EGFR)-tyrosine kinase inhibitors (TKIs) have significantly improved the prognosis of advanced non-small cell lung cancer (NSCLC) patients with EGFR mutations, patients often develop resistance to these drugs. There is therefore a need to identify new drug candidates with multitarget potential for treating NSCLC. We hereby provide preclinical evidence of the therapeutic efficacy of NLOC-015A a multitarget small-molecule inhibitor of EGFR/mitogen-activated protein (MAP) kinase kinase 1 (MAP2K1)/mammalian target of rapamycin (mTOR)/yes-associated protein 1 (YAP1) for the treatment NSCLC. Our multi-omics analysis of clinical data from cohorts of NSCLC revealed that dysregulation of EGFR/MAP2K1/mTOR/YAP1 signaling pathways was associated with the progression, therapeutic resistance, immune-invasive phenotypes, and worse prognoses of NSCLC patients. Analysis of single-cell RNA sequencing datasets revealed that MAP2K1, mTOR, YAP1 and EGFR were predominantly located on monocytes/macrophages, Treg and exhaustive CD8 T cell, and are involved in M2 polarization within the TME of patients with primary and metastatic NSCLC which further implied gene’s role in remodeling the tumor immune microenvironment. A molecular-docking analysis revealed that NLOC-015A bound to YAP1, EGFR, MAP kinase/extracellular signal-related kinase kinase 1 (MEK1), and mTOR with strong binding efficacies ranging –8.4 to –9.50 kcal/mol. Interestingly, compared to osimertinib, NLOC-015 bound with higher efficacy to the tyrosine kinase (TK) domains of both T790M and T790M/C797S mutant-bearing EGFR. Our in vitro studies and sequencing analysis revealed that NLOC-015A inhibited the proliferation and oncogenic phenotypes of NSCLC cell lines with concomitant downregulation of expression levels of mTOR, EGFR, YAP1, and MEK1 signaling network. We, therefore, suggest that NLOC-015A might represent a new candidate for treating NSCLC via acting as a multitarget inhibitor of EGFR, mTOR/NF-κB, YAP1, MEK1 in NSCLC.

Dissecting miRNA–Gene Networks to Map Clinical Utility Roads of Pharmacogenomics-Guided Therapeutic Decisions in Cardiovascular Precision Medicine

MicroRNAs (miRNAs) create systems networks and gene-expression circuits through molecular signaling and cell interactions that contribute to health imbalance and the emergence of cardiovascular disorders (CVDs). Because the clinical phenotypes of CVD patients present a diversity in their pathophysiology and heterogeneity at the molecular level, it is essential to establish genomic signatures to delineate multifactorial correlations, and to unveil the variability seen in therapeutic intervention outcomes. The clinically validated miRNA biomarkers, along with the relevant SNPs identified, have to be suitably implemented in the clinical setting in order to enhance patient stratification capacity, to contribute to a better understanding of the underlying pathophysiological mechanisms, to guide the selection of innovative therapeutic schemes, and to identify innovative drugs and delivery systems. In this article, the miRNA–gene networks and the genomic signatures resulting from the SNPs will be analyzed as a method of highlighting specific gene-signaling circuits as sources of molecular knowledge which is relevant to CVDs. In concordance with this concept, and as a case study, the design of the clinical trial GESS (NCT03150680) is referenced. The latter is presented in a manner to provide a direction for the improvement of the implementation of pharmacogenomics and precision cardiovascular medicine trials.

Musarin, a novel protein with tyrosine kinase inhibitory activity from Trametes versicolor, inhibits colorectal cancer stem cell growth

Colorectal cancer is the second deadly cancer in the world. Trametes versicolor is a traditional Chinese medicinal mushroom with a long history of being used to regulate immunity and prevent cancer. Trametes versicolor mushroom extract demonstrates strongly cell growth inhibitory activity on human colorectal tumor cells. In this study, we characterized a novel 12-kDa protein that named musarin, which was purified from Trametes versicolor mushroom extract and showed significant growth inhibition on multiple human colorectal cancer cell lines in vitro. The protein sequence of musarin was determined through enzyme digestion and MS/MS analysis. Furthermore, Musarin, in particular, strongly inhibits aggressive human colorectal cancer stem cell-like CD24+CD44+ HT29 proliferation in vitro and in a NOD/SCID murine xenograft model. Through whole transcription profile and gene enrichment analysis of musarin-treated CSCs-like cells, major signaling pathways and network modulated by musarin have been enriched, including the bioprocess of the Epithelial-Mesenchymal Transition, the EGFR-Ras signaling pathway and enzyme inhibitor activity. Musarin demonstrated tyrosine kinase inhibitory activity in vitro. Musarin strongly attenuated EGFR expression and down-regulated phosphorylation level, thereby slowing cancer cells proliferation. In addition, oral ingestion of musarin significantly inhibited CD24+CD44+ HT29 generated tumor development in SCID/NOD mice with less side effects in microgram doses. Targeting self-renewal aggressive stem-cell like cancer cell proliferation, with higher water solubility and lower cytotoxicity, musarin has shown strong potence to be developed as a promising novel therapeutic drug candidate against colorectal cancers, especially those that acquire chemo-resistance.

Complementarity principle in terms of electron density for the study of EGFR complexes

The complementarity principle is a well-established concept in the field of chemistry and biology. This concept is widely studied as the lock-and-key relationship between two structures, such as enzyme and ligand interactions. These interactions are based on the overlap of electron clouds between two structures. In this study, a mathematical relation determining complementarity of intermolecular contacts in terms of overlaps of electron clouds was examined using a quantum orbital-free AlteQ method developed in-house for 64 EGFR-ligand complexes with experimentally measured binding affinity data. A very high correlation was found between the overlap of ligand and enzyme electron clouds and the calculated terms, providing a good basis for prognosis of bioactivity and for molecular docking studies.

The Effect of the EGFR - Targeting Compound 3-[(4-Phenylpyrimidin-2-yl) Amino] Benzene-1-Sulfonamide (13f) against Cholangiocarcinoma Cell Lines

OBJECTIVE

Cholangiocarcinoma (CCA) is a noxious malignancy of epithelium of the bile duct with a low response rate to chemotherapy. The epidermal growth factor receptor (EGFR) signaling pathway is implicated in the development of cancerous cells, especially CCA. In this study, we report detailed biological profiling of 13f identified from our earlier hit expansion studies. The aim of this work was to expand our understanding of 13f via more detailed investigations of its mechanism of action against KKU-100, KKU-452 and KKU-M156 CCA cells, as well as in comparison to the EGFR inhibitor Gefitinib and non-specific chemotherapeutic agents such as Cisplatin.

METHODS

Inhibiting EGFR-Kinase, cytotoxicity, clonogenic assay, wound healing and apoptosis were performed. Levels of total expression of EGFR and EGFR phosphorylation proteins were detected.

RESULTS

13f was confirmed as an inhibitor of EGFR with an IC50 value against the tyrosine kinase of EGFR of 22 nM and IC50 values for 48 h incubation period were 1.3 ± 1.9, 1.5 ± 0.4 and 1.7 ± 1.1 µM of KKU-100, KKU-452 and KKU-M156, respectively through dose- and time-dependent induction of early apoptosis of CCA cells. The compound also suppressed the clonogenic ability of KKU-100 and KKU-M156 cells stronger than Gefitinib, while potently inhibiting EGF-stimulated CCA cell migratory activity in KKU-452 cells. It was observed that under normal conditions EGFR was activated in CCA cells. EGF-stimulated basal expression of EGFR in KKU-452 cells was suppressed following 13f treatment, which was significantly greater than that of the marketed EGFR inhibitor Gefitinib.

CONCLUSION

In summary, our study showed that 13f has potent anti-cancer activities including antiproliferation, clonogenic ability and migration through the modulation of EGFR signaling pathway in CCA for the first time. The compound represents an interesting starting point as a potential chemotherapeutic agent in ongoing efforts to improve response rate in CCA patients.
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Effect of Combining EGFR Tyrosine Kinase Inhibitors and Cytotoxic Agents on Cholangiocarcinoma Cells

Purpose

The potential of members of the epidermal growth factor receptor (ErbB) family as drug targets in cholangiocarcinoma (CCA) has not been extensively addressed. Although phase III clinical trials showed no survival benefits of erlotinib in patients with advanced CCA, the outcome of the standard-of-care chemotherapy treatment for CCA, gemcitabine/cisplatin, is discouraging so we determined the effect of other ErbB receptor inhibitors alone or in conjunction with chemotherapy in CCA cells.

Materials and Methods

ErbB receptor expression was determined in CCA patient tissues by immunohistochemistry and digital-droplet polymerase chain reaction, and in primary cells and cell lines by immunoblot. Effects on cell viability and cell cycle distribution of combination therapy using ErbB inhibitors with chemotherapeutic drugs was carried out in CCA cell lines. 3D culture of primary CCA cells was then adopted to evaluate the drug effect in a setting that more closely resembles in vivo cell environments.

Results

CCA tumors showed higher expression of all ErbB receptors compared with resection margins. Primary and CCA cell lines had variable expression of erbB receptors. CCA cell lines showed decreased cell viability when treated with chemotherapeutic drugs (gemcitabine and 5-fluorouracil) but also with ErbB inhibitors, particularly afatinib, and with a combination. Sequential treatment of gemcitabine with afatinib was particularly effective. Co-culture of CCA primary cells with cancer-associated fibroblasts decreased sensitivity to chemotherapies, but sensitized to afatinib.

Conclusion

Afatinib is a potential epidermal growth factor receptor targeted drug for CCA treatment and sequential treatment schedule of gemcitabine and afatinib could be explored in CCA patients.

Classical and Non-Classical Progesterone Signaling in Breast Cancers

Much emphasis is placed on estrogen (E2) and estrogen receptor (ER) signaling as most research is focused on understanding E2 and ER’s ability to enhance proliferative signals in breast cancers. Progesterone (P4) is important for normal mammary gland development, function and menstrual control. However, P4 and its receptors (PRs) in breast cancer etiology continue to be understudied and its role in breast cancer remains controversial. The Women’s Health Initiative (WHI) clinical trial clearly demonstrated the importance of progestogens in breast cancer development. P4 has historically been associated with classical-signaling through nuclear receptors, however non-classical P4 signaling via membrane receptors has been described. Progestogens have the ability to bind to nuclear and membrane receptors and studies have demonstrated that both can promote breast cancer cell proliferation and breast tumor growth. In this review, we attempt to understand the classical and non-classical signaling role of P4 in breast cancers because both nuclear and membrane receptors could become viable therapeutic options for breast cancer patients.

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.

Prognostic value of TP53 concurrent mutations for EGFR- TKIs and ALK-TKIs based targeted therapy in advanced non-small cell lung cancer: a meta-analysis

Background

The prognostic significance of TP53 concurrent mutations in patients with epidermal growth factor receptor (EGFR)- or anaplastic lymphoma kinase (ALK)- mutated advanced non–small-cell lung cancer (NSCLC) who received EGFR-tyrosine kinase inhibitors (TKIs) or ALK-TKIs based targeted therapy remains controversial. Therefore, the present meta-analysis was performed to investigate the association between TP53 concurrent mutations and prognosis of patients with advanced NSCLC undergoing EGFR-TKIs or ALK-TKIs treatments.

Methods

Eligible studies were identified by searching the online databases PubMed, Embase, Medline, The Cochrane library and Web of Science. Hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to clarify the correlation between TP53 mutation status and prognosis of patients. This meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

In total, 15 studies with 1342 patients were included for final analysis. Overall, concurrent TP53 mutation was associated with unfavorable progression-free survival (PFS) (HR = 1.88, 95%CI: 1.59–2.23, p < 0.001, I² = 0.0%, P = 0.792) and overall survival (OS) (HR = 1.92, 95%CI: 1.55–2.38, p < 0.001, I² = 0.0%, P = 0.515). Subgroup analysis based on type of targeted therapy (EGFR-TKIs or ALK-TKIs, pathological type of cancer (adenocarcinoma only or all NSCLC subtypes) and line of treatment (first-line only or all lines) all showed that TP53 mutations was associated with shorter survivals of patients with EGFR-TKIs or ALK-TKIs treatments. Particularly, in patients with first-line EGFR-TKIs treatment, significantly poorer prognosis was observed in patients with TP53 concurrent mutations (pooled HR for PFS: 1.69, 95% CI 1.25–2.27, P < 0.001, I² = 0.0%, P = 0.473; pooled HR for OS: 1.94, 95% CI 1.36–2.76, P < 0.001, I² = 0.0%, P = 0.484). Begg’s funnel plots and Egger’s tests indicated no significant publication bias in this study.

Conclusions

This meta-analysis indicated that concurrent TP53 mutations was a negative prognostic factor and associated with poorer outcomes of patients with EGFR-TKIs or ALK-TKIs treatments in advanced NSCLC. In addition, our study provided evidence that TP53 mutations might be involved in primary resistance to EGFR-TKIs treatments in patients with sensitive EGFR mutations in advanced NSCLC.

A Retrospective Look at Anti-EGFR Agents in Pancreatic Cancer Therapy

BACKGROUND

The introduction of Monoclonal Antibodies (mAbs) and small-molecule Tyrosine Kinase Inhibitors (TKIs) that target the Epidermal Growth Factor Receptor (EGFR), marks a huge step forward in the Pancreatic Cancer (PC) therapy. However, anti-EGFR therapy is found to be successful only in a fraction of patients. Although anti-EGFR agents have shown considerable clinical promise, a serious adverse event associated with anti- EGFR therapy has been challenging. At this juncture, there is still more to be done in the search for effective predictive markers with therapeutic applicability.

METHODS

A focused literature search was conducted to summarize the existing evidence on anti-EGFR agents in pancreatic cancer therapy.

RESULTS

This review discusses various anti-EGFR agents currently in use for PC therapy and potential adverse effects associated with it. Existing evidence on EGFR TKIs demonstrated better tolerant effects and outcomes with multiple toxic regimens. Anti-EGFR therapy in combination with chemotherapy is necessary to achieve the best clinical outcomes.

CONCLUSION

Future prospective studies on the identification of additional biological agents and novel anti-EGFR agents are warranted.

miR-133b inhibits cell proliferation, migration and invasion of esophageal squamous cell carcinoma by targeting EGFR

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is an aggressive tumor entity characterized by early metastasis and late diagnosis. MicroRNA-133b (miR-133b) has been considered as a tumor suppressor in many human cancers by regulating epidermal growth factor receptor (EGFR). However, the specific effects of miR-133b and EGFR on ESCC remain unclear.

METHODS

qRT-PCR and western blotting were applied for measuring expression of mRNA and protein. Flow cytometry was used for detecting cell cycle and apoptosis. Cell proliferation, migration and invasion were detected by colony formation and transwell assays. Luciferase reporter assay was used to confirm the interaction between miR-133b and EGFR.

RESULTS

Low expression of miR-133b and high expression of EGFR were identified in ESCC cells and tissues. Overexpression of miR-133b or knockdown of EGFR suppressed the cell proliferation, migration, and invasion of ESCC cells, and raised the percentage of G1 phase cells. The apoptosis of ESCC cells were promoted by increasing miR-133b and decreasing EGFR expression. Luciferase reporter assay confirmed EGFR as the target of miR-133b in ESCC cells. Overexpression of miR-133b significantly decreased the phosphorylation of PI3K, ERK and AKT by directly down-regulating EGFR. Higher expression of E-cadherin and CK-18 and lower expression of Vimentin and N-cadherin were observed after the transfection of miR-133b mimics or shEGFR.

CONCLUSION

Overexpression of miR-133b could suppress proliferation, migration and invasion of ESCC cells by inhibiting MAPK/ERK and PI3K/AKT signaling pathways through targeting EGFR, indicating that miR-133b might be a potential therapeutic target for the treatment of ESCC.

The E3 ubiquitin ligase NEDD4 mediates cell migration signaling of EGFR in lung cancer cells

BACKGROUND

EGFR-dependent cell migration plays an important role in lung cancer progression. Our previous study observed that the HECT E3 ubiquitin ligase NEDD4 is significantly correlated with tumor metastasis and required for migration and invasion signaling of EGFR in gastric cancer cells. However, how NEDD4 promotes the EGFR-dependent lung cancer cell migration is unknown. This study is to elucidate the mechanism by which NEDD4 mediates the EGFR lung cancer migration signaling.

METHODS

Lentiviral vector-loaded NEDD4 shRNA was used to deplete endogenous NEDD4 in lung cancer cell lines. Effects of the NEDD4 knockdown on the EGFR-dependent or independent lung cancer cell migration were determined using the wound-healing and transwell assays. Association of NEDD4 with activated EGFR was assayed by co-immunoprecipitation. Co-expression of NEDD4 with EGFR or PTEN was determined by immunohistochemical (IHC) staining in 63 lung adenocarcinoma tissue samples. Effects of NEDD4 ectopic expression or knockdown on PTEN ubiquitination and down-regulation, AKT activation and lysosomal secretion were examined using the GST-Uba pulldown assay, immunoblotting, immunofluorescent staining and a human cathepsin B ELISA assay respectively. The specific cathepsin B inhibitor CA-074Me was used for assessing the role of cathepsin B in lung cancer cell migration.

RESULTS

Knockdown of NEDD4 significantly reduced EGF-stimulated cell migration in non-small cell lung carcinoma (NSCLC) cells. Co-immunoprecipitation assay found that NEDD4 is associated with EGFR complex upon EGF stimulation, and IHC staining indicates that NEDD4 is co-expressed with EGFR in lung adenocarcinoma tumor tissues, suggesting that NEDD4 might mediate lung cancer cell migration by interaction with the EGFR signaling complex. Interestingly, NEDD4 promotes the EGF-induced cathepsin B secretion, possibly through lysosomal exocytosis, as overexpression of the ligase-dead mutant of NEDD4 impedes lysosomal secretion, and knockdown of NEDD4 significantly reduced extracellular amount of cathepsin B induced by EGF. Consistent with the role of NEDD4, cathepsin B is pivotal for both basal and the EGF-stimulated lung cancer cell migration. Our studies propose a novel mechanism underlying the EGFR-promoted lung cancer cell migration that is mediated by NEDD4 through regulation of cathepsin B secretion.

CONCLUSION

NEDD4 mediates the EGFR lung cancer cell migration signaling through promoting lysosomal secretion of cathepsin B.

The Future of Anti-EGFR Therapy

We report here on the state of our knowledge of the target - namely, the epidermal growth factor (EGF) and its receptor - and the challenges related to the methods of determination of the epidermal growth factor receptor (EGFR) and associated molecular pathways. A critical review of the anti-EGFR therapeutic strategies is also outlined. The chimeric anti-EGFR monoclonal antibody cetuximab has been approved for EGFR-expressing colorectal tumors in patients who progress after irinotecan-based chemotherapy in combination with irinotecan and in squamous cell head and neck carcinomas for patients with locally advanced disease in combination with radiation therapy or after failure of platinum-based chemotherapy in recurrent or metastatic disease (FDA). Cetuximab has the potential to provide an improvement of clinical outcome also in other indications and tumor types, particularly when used as first-line therapy combined with standard chemotherapy for metastatic disease or in the adjuvant setting. Possible strategies to improve the effectiveness of anti-EGFR agents are suggested and include (i) the use of predictive tools capable of making a more rational selection of patients; (ii) the development of standardized predictive biomarkers as surrogates for early monitoring of drug efficacy; and (iii) adequate study design, statistical analysis and proper end points of efficacy to be applied in future prospective trials.

NRF2 Regulates HER1 Signaling Pathway to Modulate the Sensitivity of Ovarian Cancer Cells to Lapatinib and Erlotinib

NF-E2-related factor 2 (NRF2) regulates the transcription of a battery of metabolic and cytoprotective genes. NRF2 and epidermal growth factor receptors (EGFRs/HERs) are regulators of cellular proliferation and determinants of cancer initiation and progression. NRF2 and HERs confer cancers with resistance to several therapeutic agents. Nevertheless, there is limited understanding of the regulation of HER expression and activation and the link between NRF2 and HER signalling pathways. We show that NRF2 regulates both basal and inducible expression of HER1, as treatment of ovarian cancer cells (PEO1, OVCAR3, and SKOV3) with NRF2 activator tBHQ inducing HER1, while inhibition of NRF2 by siRNA knockdown or with retinoid represses HER1. Furthermore, treatment of cells with tBHQ increased total and phosphorylated NRF2, HER1, and AKT levels and compromised the cytotoxic effect of lapatinib or erlotinib. Treatment with siRNA or retinoid antagonised the effect of tBHQ on NRF2 and HER1 levels and enhanced the sensitivity of ovarian cancer cells to lapatinib or erlotinib. Pharmacological or genetic inhibition of NRF2 and/or treatment with lapatinib or erlotinib elevated cellular ROS and depleted glutathione. This extends the understanding of NRF2 and its regulation of HER family receptors and opens a strategic target for improving cancer therapy.

Migration of oral squamous cell carcinoma cells are induced by HGF/c-Met signalling via lamellipodia and filopodia formation

The activation of receptor tyrosine kinases (RTKs) results in cellular effects including cell proliferation, survival, migration and invasion; RTKs also play an important role in tumourigenesis. It has been reported that EGFR signalling controls the migration of oral squamous cell carcinoma (OSCC) SAS and HSC3 cells but not of HSC4 cells, although the proliferation of HSC4 cells is regulated by EGF/EGFR. In the present study, we investigated the roles of EGFR and the c-Met signalling pathway in cell migration via filopodia and lamellipodia formation, which may be prerequisites for migration. To explore the role of c-Met in cell migration, we inhibited c-Met RTK activity using the c-Met inhibitor SU11274 and activated c-Met using hepatocyte growth factor (HGF) in three OSCC cell lines HSC4, SAS and Ca9-22 and investigated migration potency using a wound healing assay. We showed that inhibition of c-Met significantly suppressed, and activation of c-Met significantly promoted, the migration of OSCC cells. Additionally, the migration of SAS and Ca9-22 cells was inhibited by the EGFR inhibitors AG1478 and cetuximab and promoted by EGF treatment. Moreover, migration potency was correlated with lamellipodia formation. Furthermore, western blot analyses demonstrated that SU11274 decreased and HGF increased lamellipodin protein levels as well as phosphorylated c-Met levels. Collectively, we demonstrated that c-Met signalling induced lamellipodia formation by upregulating lamellipodin, thereby promoting the migration of OSCC cells.

A unique microRNA profile in end-stage heart failure indicates alterations in specific cardiovascular signaling networks

It is well established that the gene expression patterns are substantially altered in cardiac hypertrophy and heart failure, however, less is known about the reasons behind such global differences. MicroRNAs (miRNAs) are short non-coding RNAs that can target multiple molecules to regulate wide array of proteins in diverse pathways. The goal of the study was to profile alterations in miRNA expression using end-stage human heart failure samples with an aim to build signaling network pathways using predicted targets for the altered miRNA and to determine nodal molecules regulating individual networks. Profiling of miRNAs using custom designed microarray and validation with an independent set of samples identified eight miRNAs that are altered in human heart failure including one novel miRNA yet to be implicated in cardiac pathology. To gain an unbiased perspective on global regulation by top eight altered miRNAs, functional relationship of predicted targets for these eight miRNAs were examined by network analysis. Ingenuity Pathways Analysis network algorithm was used to build global signaling networks based on the targets of altered miRNAs which allowed us to identify participating networks and nodal molecules that could contribute to cardiac pathophysiology. Majority of the nodal molecules identified in our analysis are targets of altered miRNAs and known regulators of cardiovascular signaling. Cardio-genomics heart failure gene expression public data base was used to analyze trends in expression pattern for target nodal molecules and indeed changes in expression of nodal molecules inversely correlated to miRNA alterations. We have used NF kappa B network as an example to show that targeting other molecules in the network could alter the nodal NF kappa B despite not being a miRNA target suggesting an integrated network response. Thus, using network analysis we show that altering key functional target proteins may regulate expression of the myriad signaling pathways underlying the cardiac pathology.

Current status of biomarker and targeted nanoparticle development: The precision oncology approach for pancreatic cancer therapy

Pancreatic cancer remains one of the major causes of cancer-related mortality. The majority of pancreatic cancer patients are diagnosed at the advanced stage with unresectable and drug resistant tumors. The new treatments with the combination of chemotherapy, molecular targeted therapy, and immunotherapy have shown modest effects on therapeutic efficacy and survival of the patients. Therefore, there is an urgent need to develop effective therapeutic approaches targeting highly heterogeneous pancreatic cancer cells and tumor microenvironments. Recent advances in biomarker targeted cancer therapy and image-guided drug delivery and monitoring treatment response using multifunctional nanoparticles, also referred to as theranostic nanoparticles, offer a new opportunity of effective detection and treatment of pancreatic cancer. Increasing evidence from preclinical studies has shown the potential of applications of theranostic nanoparticles for designing precision oncology approaches for pancreatic cancer therapy. In this review, we provide an update on the current understanding and strategies for the development of targeted therapy for pancreatic cancer using nanoparticle drug carriers. We address issues concerning drug delivery barriers in stroma rich pancreatic cancer and the potential approaches to improve drug delivery efficiency, therapeutic responses and tumor imaging. Research results presented in this review suggest the development of an integrated therapy protocol through image-guided and targeted drug delivery and therapeutic effect monitoring as a promising precision oncology strategy for pancreatic cancer treatment.

Population pharmacokinetics of HM781-36 (poziotinib), pan-human EGF receptor (HER) inhibitor, and its two metabolites in patients with advanced solid malignancies

PURPOSE

To develop a population pharmacokinetic (PK) model for HM781-36 (poziotinib) and its metabolites in cancer patients.

METHODS

Blood samples were collected from three phase I studies in which fifty-two patients received oral HM781-36B tablets (0.5-32 mg) once daily for 2 weeks, and another 20 patients received oral HM781-36B tablets (12, 16, 18, 24 mg) in fasting (12 patients) or fed (eight patients) state once daily for 4 weeks. Nonlinear mixed effect modeling was employed to develop the population pharmacokinetic model.

RESULTS

HM781-36 PK was ascribed to a two-compartment model and HM781-36-M1/-M2 PK to one-compartment model. HM781-36 oral absorption was characterized by first-order input (absorption rate constant: 1.45 ± 0.23 h⁻¹). The central volume of distribution (185 ± 12.7 L) was influenced significantly by body weight. The absorption rate constant was influenced by food. The typical HM781-36 apparent clearance was 34.5 L/h (29.4 %CV), with an apparent peripheral volume of distribution of 164 L (53.5 %CV). Other covariates did not significantly further explain the PKs of HM781-36.

CONCLUSIONS

The proposed model suggests that HM781-36 PKs are consistent across most solid tumor types, and that the absorption process of HM781-36 is affected by the fed state before dosing. HM781-36 PKs are not complicated by patient factors, other than body weight.

Chronopharmacology and mechanism of antitumor effect of erlotinib in Lewis tumor-bearing mice

The epidermal growth factor receptor (EGFR), a ubiquitously expressed receptor tyrosine kinase, is recognized as a key mediator of tumorigenesis in many human epithelial tumors. Erlotinib is tyrosine kinase inhibitor approved by FDA for use in oncology. It inhibits the intracellular phosphorylation of tyrosine kinase associated with the EGFR to restrain the development of the tumor. To investigate the antitumor effect of erlotinib at different dosing times and the underlying molecular mechanism via the PI3K/AKT pathway, we established a mouse model of Lewis lung cancer xenografts. The tumor-bearing mice were housed four or five per cage under standardized light-dark cycle conditions (light on at 7:00 AM, 500 Lux, off at 7:00 PM, 0 Lux) with food and water provided ad libitum. The mice were observed for quality of life, their body weight and tumor volume measured, and the tumor growth curves drawn. After being bled, the mice were sacrificed by cervical dislocation. The tumor masses were removed at different time points and weighed. The mRNA expression of EGFR, AKT, Cyclin D1 and CDK-4 were assayed by quantitative real-time PCR (qRT-PCR). Protein expression levels of AKT, P-AKT and Cyclin D1 were determined by Western blot analysis. The results suggest that erlotinib has a significant antitumor effect on xenografts of non-small cell lung cancer in mice, and its efficacy and toxicity is dependent on the time of day of administration. Its molecular mechanism of action might be related to the EGFR-AKT-Cyclin D1-CDK-4 pathway which plays a crucial role in the development of pathology. Therefore, our findings suggest that the time of day of administration of Erlotinib may be a clinically important variable.

Ligand-conjugated mesoporous silica nanorattles based on enzyme targeted prodrug delivery system for effective lung cancer therapy

Epidermal growth factor receptor antibody (EGFRAb) conjugated silica nanorattles (SNs) were synthesized and used to develop receptor mediated endocytosis for targeted drug delivery strategies for cancer therapy. The present study determined that the rate of internalization of silica nanorattles was found to be high in lung cancer cells when compared with the normal lung cells. EGFRAb can specifically bind to EGFR, a receptor that is highly expressed in lung cancer cells, but is expressed at low levels in other normal cells. Furthermore, in vitro studies clearly substantiated that the cPLA2α activity, arachidonic acid release and cell proliferation were considerably reduced by pyrrolidine-2 loaded EGFRAb-SN in H460 cells. The cytotoxicity, cell cycle arrest and apoptosis were significantly induced by the treatment of pyrrolidine-2 loaded EGFRAb-SN when compared with free pyrrolidine-2 and pyrrolidine-2 loaded SNs in human non-small cell lung cancer cells. An in vivo toxicity assessment showed that silica nanorattles and EGFRAb-SN-pyrrolidine-2 exhibited low systemic toxicity in healthy Balb/c mice. The EGFRAb-SN-pyrrolidine-2 showed a much better antitumor activity (38%) with enhanced tumor inhibition rate than the pyrrolidine-2 on the non-small cell lung carcinoma subcutaneous model. Thus, the present findings validated the low toxicity and high therapeutic potentials of EGFRAb-SN-pyrrolidine-2, which may provide a convincing evidence of the silica nanorattles as new potential carriers for targeted drug delivery systems.

Management of dermatologic toxicities associated with monoclonal antibody epidermal growth factor receptor inhibitors: A case review

INTRODUCTION

The epidermal growth factor receptor inhibitors (EGFRIs), cetuximab and panitumumab, represent an effective treatment option for patients affected by metastatic colorectal cancer (mCRC); furthermore, they are relatively devoid of systemic toxicities, which are commonly observed with standard cytotoxic chemotherapy. However, the majority of patients treated with these monoclonal antibodies (mAbs), will experience dermatologic toxicities, most notably the papulopustular skin rash, which can impact quality-of-life and affect adherence to therapy. This paper reviews the most recent practices in the management of skin rash related to anti-epidermal growth factor receptor (EGFR) mAbs, cetuximab and panitumumab, in the treatment of mCRC.

MATERIALS AND METHODS

We reviewed relevant literature regarding dermatologic toxicities associated with anti-EGFR mAbs in order to give important indications about prevention and reactive treatment of skin rash.

RESULTS

Two case reports were presented to show how skin rash could hamper mAb EGFRIs use in clinical practice, underscoring the need of implementing a comprehensive management strategy of skin toxicity in order to promote patients' compliance with anti-EGFR therapy and maintain quality-of-life. Based on randomized data, recent guidelines established by the Multinational Association for Supportive Care in Cancer Skin Toxicity Study Group suggest that prophylactic use of oral doxycycline or minocycline reduces the risk and severity of skin rash, improving clinical outcomes.

CONCLUSIONS

At the start of treatment with cetuximab and panitumumab, the proper patient education about the skin rash associated with these mAbs and the implementation of a pre-emptive, comprehensive skin toxicity program significantly contribute to improve adherence to therapy, optimize anti-EGFR therapy and maintain quality-of-life.

Autotaxin and lysophosphatidic acid signalling in lung pathophysiology

Autotaxin (ATX or ENPP2) is a secreted glycoprotein widely present in biological fluids. ATX primarily functions as a plasma lysophospholipase D and is largely responsible for the bulk of lysophosphatidic acid (LPA) production in the plasma and at inflamed and/or malignant sites. LPA is a phospholipid mediator produced in various conditions both in cells and in biological fluids, and it evokes growth-factor-like responses, including cell growth, survival, differentiation and motility, in almost all cell types. The large variety of LPA effector functions is attributed to at least six G-protein coupled LPA receptors (LPARs) with overlapping specificities and widespread distribution. Increased ATX/LPA/LPAR levels have been detected in a large variety of cancers and transformed cell lines, as well as in non-malignant inflamed tissues, suggesting a possible involvement of ATX in chronic inflammatory disorders and cancer. In this review, we focus exclusively on the role of the ATX/LPA axis in pulmonary pathophysiology, analysing the effects of ATX/LPA on pulmonary cells and leukocytes in vitro and in the context of pulmonary pathophysiological situations in vivo and in human diseases.

Interrogating tumor metabolism and tumor microenvironments using molecular positron emission tomography imaging. Theranostic approaches to improve therapeutics

Positron emission tomography (PET) is a noninvasive molecular imaging technology that is becoming increasingly important for the measurement of physiologic, biochemical, and pharmacological functions at cellular and molecular levels in patients with cancer. Formation, development, and aggressiveness of tumor involve a number of molecular pathways, including intrinsic tumor cell mutations and extrinsic interaction between tumor cells and the microenvironment. Currently, evaluation of these processes is mainly through biopsy, which is invasive and limited to the site of biopsy. Ongoing research on specific target molecules of the tumor and its microenvironment for PET imaging is showing great potential. To date, the use of PET for diagnosing local recurrence and metastatic sites of various cancers and evaluation of treatment response is mainly based on [(18)F]fluorodeoxyglucose ([(18)F]FDG), which measures glucose metabolism. However, [(18)F]FDG is not a target-specific PET tracer and does not give enough insight into tumor biology and/or its vulnerability to potential treatments. Hence, there is an increasing need for the development of selective biologic radiotracers that will yield specific biochemical information and allow for noninvasive molecular imaging. The possibility of cancer-associated targets for imaging will provide the opportunity to use PET for diagnosis and therapy response monitoring (theranostics) and thus personalized medicine. This article will focus on the review of non-[(18)F]FDG PET tracers for specific tumor biology processes and their preclinical and clinical applications.

Gene expression profiles can predict panitumumab monotherapy responsiveness in human tumor xenograft models

BACKGROUND

Epidermal growth factor receptor (EGFR)-targeted agents have demonstrated clinical benefit in patients with cancer. Identifying tissue-of-origin-independent predictive biomarkers is important to optimally treat patients. We sought to identify a gene array profile that could predict responsiveness to panitumumab, a fully human EGFR-binding antibody, using preclinical models of human cancer.

METHODS

Mice bearing 25 different xenograft models were treated twice weekly with panitumumab or immunoglobulin G2 control to determine their responsiveness to panitumumab. Samples from these xenografts and untreated xenografts were arrayed on the Affymetrix human U133A gene chip to identify gene sets predicting responsiveness to panitumumab using univariate and multivariate analyses. The predictive models were validated using the leave-one-group-out (LOO) method.

RESULTS

Of the 25 xenograft models tested, 12 were responsive and 13 were resistant to panitumumab. Unsupervised analysis demonstrated that the xenograft models clustered by tissue type rather than responsiveness to panitumumab. After normalizing for tissue effects, samples clustered by responsiveness using an unsupervised multidimensional scaling. A multivariate selection algorithm was used to select 13 genes that could stratify xenograft models based on responsiveness after adjustment for tissue effects. The method was validated using the LOO method on a training set of 22 models and confirmed independently on three new models. In contrast, a univariate gene selection method resulted in higher misclassification rates.

CONCLUSION

A model was constructed from microarray data that prospectively predict responsiveness to panitumumab in xenograft models. This approach may help identify patients, independent of disease origin, likely to benefit from panitumumab.

Cetuximab response of lung cancer-derived EGF receptor mutants is associated with asymmetric dimerization

Kinase domain mutations of the EGF receptor (EGFR) are common oncogenic events in lung adenocarcinoma. Here, we explore the dependency upon asymmetric dimerization of the kinase domain for activation of lung cancer-derived EGFR mutants. We show that whereas wild-type EGFR and the L858R mutant require dimerization for activation and oncogenic transformation, the exon 19 deletion, exon 20 insertion, and L858R/T790M EGFR mutants do not require dimerization. In addition, treatment with the monoclonal antibody, cetuximab, shrinks mouse lung tumors induced by the dimerization-dependent L858R mutant, but exerts only a modest effect on tumors driven by dimerization-independent EGFR mutants. These data imply that different EGFR mutants show differential requirements for dimerization and that disruption of dimerization may be among the antitumor mechanisms of cetuximab.

Pharmacokinetics, pharmacodynamics and physiologically-based pharmacokinetic modelling of monoclonal antibodies

Development of monoclonal antibodies (mAbs) and their functional derivatives represents a growing segment of the development pipeline in the pharmaceutical industry. More than 25 mAbs and derivatives have been approved for a variety of therapeutic applications. In addition, around 500 mAbs and derivatives are currently in different stages of development. mAbs are considered to be large molecule therapeutics (in general, they are 2-3 orders of magnitude larger than small chemical molecule therapeutics), but they are not just big chemicals. These compounds demonstrate much more complex pharmacokinetic and pharmacodynamic behaviour than small molecules. Because of their large size and relatively poor membrane permeability and instability in the conditions of the gastrointestinal tract, parenteral administration is the most usual route of administration. The rate and extent of mAb distribution is very slow and depends on extravasation in tissue, distribution within the particular tissue, and degradation. Elimination primarily happens via catabolism to peptides and amino acids. Although not definitive, work has been published to define the human tissues mainly involved in the elimination of mAbs, and it seems that many cells throughout the body are involved. mAbs can be targeted against many soluble or membrane-bound targets, thus these compounds may act by a variety of mechanisms to achieve their pharmacological effect. mAbs targeting soluble antigen generally exhibit linear elimination, whereas those targeting membrane-bound antigen often exhibit non-linear elimination, mainly due to target-mediated drug disposition (TMDD). The high-affinity interaction of mAbs and their derivatives with the pharmacological target can often result in non-linear pharmacokinetics. Because of species differences (particularly due to differences in target affinity and abundance) in the pharmacokinetics and pharmacodynamics of mAbs, pharmacokinetic/pharmacodynamic modelling of mAbs has been used routinely to expedite the development of mAbs and their derivatives and has been utilized to help in the selection of appropriate dose regimens. Although modelling approaches have helped to explain variability in both pharmacokinetic and pharmacodynamic properties of these drugs, there is a clear need for more complex models to improve understanding of pharmacokinetic processes and pharmacodynamic interactions of mAbs with the immune system. There are different approaches applied to physiologically based pharmacokinetic (PBPK) modelling of mAbs and important differences between the models developed. Some key additional features that need to be accounted for in PBPK models of mAbs are neonatal Fc receptor (FcRn; an important salvage mechanism for antibodies) binding, TMDD and lymph flow. Several models have been described incorporating some or all of these features and the use of PBPK models are expected to expand over the next few years.

EGFR inhibitors sensitize non-small cell lung cancer cells to TRAIL-induced apoptosis

Apoptosis induced by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can be regulated by the epidermal growth factor (EGF) signaling pathway. In this study, recombinant adenoviral vectors that encode TRAIL gene from the hTERT/RGD promoter (AdTRAIL) was combined with drugs including gefitinib, elotinib, and cetuximab that inhibit EGFR and the EGF signaling pathway in non–small cell lung cancer (NSCLC) cell lines to investigate their antitumor activity. In vitro, compared to single reagent, AdTRAIL combined with EGFR inhibitors reduced proliferation and enhanced apoptosis in H460, A549, and SW1573 cell lines. Western blot results suggested that these effects were relative to upregulation of pro-apoptosis protein BAX and down-regulation of p-AKT. In vivo, AdTRAIL combined with cetuximab resulted in a significant growth reduction in H460 xenografts without damage to the main organs of nude mice. Histological examination and TUNEL analyses of xenografts showed that cetuximab enhanced cell apoptosis induced by AdTRAIL. These results indicate that EGFR inhibitors enhanced AdTRAIL anti-tumor activity in NSCLC cell lines and that inhibiting the AKT pathway played an important role in this enhancement.

Hepatic arterial infusion but not systemic application of cetuximab in combination with oxaliplatin significantly reduces growth of CC531 colorectal rat liver metastases

PURPOSE

Systemic chemotherapy still represents the gold standard in the treatment of irresectable colorectal liver metastases. Modern anticancer agents like the monoclonal antibody cetuximab have improved the outcome of patients in clinical studies. As hepatic arterial infusion (HAI) is capable to potentially increase the anticancer effect of cytostatics, we herein studied whether HAI of cetuximab (CE) as a single agent or in combination with oxaliplatin (OX) exerts increased anticancer effects compared to the systemic application (SYS) of the drugs.

METHODS

WAG/Rij rats were randomized to eight groups and underwent 10 days after subcapsular hepatic tumor implantation either HAI or SYS of CE, OX, or the combination of both agents (CE + OX). Saline-treated animals served as controls. Tumor volume was measured at days 10 and 13 using three-dimensional ultrasound. On day 13, liver and tumor tissue was sampled for histological and immunohistochemical analysis.

RESULTS

In controls, the tumor volume significantly increased from day 10 to 13. Application of OX alone via HAI or SYS did not inhibit tumor growth compared to controls. SYS of CE or CE + OX did also not reduce tumor growth. In contrast, HAI of CE and CE + OX significantly inhibited tumor growth. HAI of CE significantly reduced tumor vascularization as measured by the number of platelet endothelial cell adhesion molecule-1-positive cells and significantly increased the number of apoptotic tumor cells as measured by the cellular caspase-3 expression.

CONCLUSION

HAI of CE and CE + OX reduces tumor growth of colorectal rat liver metastases involving the inhibition of angiogenesis and induction of tumor cell apoptosis.

The role of MMP-1 in breast cancer growth and metastasis to the brain in a xenograft model

Background

Brain metastasis is an increasingly common complication for breast cancer patients; approximately 15– 30% of breast cancer patients develop brain metastasis. However, relatively little is known about how these metastases form, and what phenotypes are characteristic of cells with brain metastasizing potential. In this study, we show that the targeted knockdown of MMP-1 in breast cancer cells with enhanced brain metastatic ability not only reduced primary tumor growth, but also significantly inhibited brain metastasis.

Methods

Two variants of the MDA-MB-231 human breast cancer cell line selected for enhanced ability to form brain metastases in nude mice (231-BR and 231-BR3 cells) were found to express high levels of matrix metalloproteinase-1 (MMP-1). Short hairpin RNA-mediated stable knockdown of MMP-1 in 231-BR and 231-BR3 cells were established to analyze tumorigenic ability and metastatic ability.

Results

Short hairpin RNA-mediated stable knockdown of MMP-1 inhibited the invasive ability of MDA-MB 231 variant cells in vitro, and inhibited breast cancer growth when the cells were injected into the mammary fat pad of nude mice. Reduction of MMP-1 expression significantly attenuated brain metastasis and lung metastasis formation following injection of cells into the left ventricle of the heart and tail vein, respectively. There were significantly fewer proliferating cells in brain metastases of cells with reduced MMP-1 expression. Furthermore, reduced MMP-1 expression was associated with decreased TGFα release and phospho-EGFR expression in 231-BR and BR3 cells.

Conclusions

Our results show that elevated expression of MMP-1 can promote the local growth and the formation of brain metastases by breast cancer cells.

MicroRNA-133 inhibits cell proliferation, migration and invasion by targeting epidermal growth factor receptor and its downstream effector proteins in bladder cancer

OBJECTIVE

MicroRNA-133a (miR-133a) and microRNA-133b (miR-133b) are located on chromosome 18 in the same bicistronic unit. Recently, they have been commonly identified as being down-regulated in various human malignancies, such as bladder cancer, pancreatic ductal adenocarcinoma, oesophageal squamous cell carcinoma of the tongue, and hepatocellular and lung carcinomas. The present study examined the effects of miR-133a and miR-133b in bladder cancer T24 and EJ cells.

MATERIAL AND METHODS

After transfection of miR-133a and miR-133b, the expression of miR-133a/b was assessed, and a cell viability assay, cell migration assay, cell invasion assay, luciferase assay and Western blot were conducted in bladder cancer T24 and EJ cells.

RESULTS

Both miR-133a and miR-133b were found to inhibit cell proliferation, migration and invasion in T24 and EJ cells. The first evidence was provided that miR-133a and miR-133b may directly target the epidermal growth factor receptor in bladder cancer.

CONCLUSIONS

This study provided the first glimpse of the functional role of miR-133 in bladder cancer T24 and EJ cells. The results may increase our knowledge on the molecular basis of progression and provide potential therapy for bladder cancer.

Liver-directed chemotherapy of cetuximab and bevacizumab in combination with oxaliplatin is more effective to inhibit tumor growth of CC531 colorectal rat liver metastases than systemic chemotherapy

Colorectal carcinoma is, through to its high rate of liver metastasis (mCRC), the second most cause of cancer death worldwide. Tumor resection represents the only potential cure. In cases of unresectable disease systemic chemotherapy (sCHT) remains the therapy of choice. Modern sCHT regimens including biological agents can induce tumor response that leads to curative surgery of initially unresectable mCRC. However, liver-directed therapy via hepatic arterial infusion (HAI) may produce higher response rates than sCHT. Herein we studied whether a HAI of cetuximab (CE) plus bevacizumab (BE) with or without oxaliplatin (OX) can inhibit tumor growth in a rat model. WAG/Rij rats underwent subcapsular hepatic tumor implantation. After 10 days animals received either HAI or sCHT of CE plus BE, OX or all three drugs. Saline-treated animals served as controls. Tumor growth was estimated at day 10 and 13. On day 13 liver and tumor tissue was studied histologically and immunohistochemically. In controls the tumors grew about 50 %. OX alone was not capable of inhibiting tumor growth. In contrast, CE plus BE given as HAI significantly reduced tumor growth compared to sCHT (p < 0.05). HAI of CE plus BE combined with OX yielded an even more pronounced inhibition of tumor growth. Immunohistochemistry revealed a decreased tumor cell proliferation and tumor vascularization. The present study demonstrates that HAI of CE plus BE is effective to inhibit tumor growth. This effect is even more pronounced in combination with OX. Systemic application of these agents cannot achieve comparable effects.

An overview of phenylcyclopropylamine derivatives: biochemical and biological significance and recent developments

trans-2-Phencylcyclopropylamine (2-PCPA), a potent, clinically used antidepressant, affects monoamine neurotransmitter levels by inhibiting the main metabolizing enzymes, monoamine oxidases (MAOs). However, the antidepressant action of this compound was not fully explained by its effects on MAOs due to its wide variety of biological effects. 2-PCPA also affects depression-associated pathophysiological pathways, and linked with increased levels of trace amines in brain, upregulation of GABAB receptors (where GABA is gamma amino butyric acid), modulation of phospholipid metabolism, and interference with various cytochrome P450 (CYP) enzymes. Consequently, despite its adverse effects and limited clinical applicability, 2-PCPA has attracted interest as a structural scaffold for the development of mechanism-based inhibitors of various enzymes, including lysine-specific demethylase 1 (LSD1), which is a possible target for cancer chemotherapy. In the recent years, many reports have appeared in the literature based on 2-PCPA scaffold and their potential medicinal implications. This review mainly focuses on the medicinal chemistry aspects including drug design, structure-activity relationships (SAR), biological and biochemical properties, and mechanism of actions of 2-PCPA and its derivatives. Furthermore, we also highlight recent advance in this area and discuss their future applications for beneficial therapeutic effects.

Tumor penetration and epidermal growth factor receptor saturation by panitumumab correlate with antitumor activity in a preclinical model of human cancer

Background

Successful treatment of solid tumors relies on the ability of drugs to penetrate into the tumor tissue.

Methods

We examined the correlation of panitumumab (an anti-epidermal growth factor [EGFR] antibody) tumor penetration and EGFR saturation, a potential obstacle in large molecule drug delivery, using pharmacokinetics, pharmacodynamics, and tumor growth rate in an A431 epidermoid carcinoma xenograft model of human cancer. To determine receptor saturation, receptor occupancy, and levels of proliferation markers, immunohistochemical and flow cytometric methods were used. Pharmacokinetic data and modeling were used to calculate growth characteristics of panitumumab-treated tumors.

Results

Treatment with panitumumab in vivo inhibited pEGFR, Ki67 and pMAPK levels vs control. Tumor penetration and receptor saturation were dose- and time-dependent, reaching 100% and 78%, respectively. Significant tumor inhibition and eradication (p < 0.05) were observed; plasma concentration associated with tumor eradication was estimated to be 0.2 μg/ml. The tumor inhibition model was able to describe the mean tumor growth and death rates.

Conclusions

These data demonstrate that the antitumor activity of panitumumab correlates with its ability to penetrate into tumor tissue, occupy and inhibit activation of EGFR, and inhibit markers of proliferation and MAPK signaling.

A critical review of lipid-based nanoparticles for taxane delivery

Nano-based delivery systems have attracted a great deal of attention in the past two decades as a strategy to overcome the low therapeutic index of conventional anticancer drugs and delivery barriers in solid tumors. Myriads of preclinical studies have been focused on developing nano-based formulations to effectively deliver taxanes, one of the most important and most prescribed anticancer drug types in the clinic. Given the hydrophobic property of taxanes, lipid-based NPs, serve as a viable alternative delivery system. This critical review will provide an overview and perspective of the advancement of lipid-based nanoparticles for taxane delivery. Currently available formulations of taxanes and their drawbacks as well as criteria for idea taxane delivery system will be discussed.

EGFR overexpression relates to triple negative profile and poor prognosis in breast cancer patients in Tunisia

BACKGROUND

The prognosis of breast carcinoma is related to a large variety of clinical and pathological factors. Currently, only oestrogen (ER) and progesterone (PR) receptors and human epidermal growth factor receptor 2 (HER2) are used in routine pathological assessment as biomarkers. The aim of this study was to evaluate the prognostic impact of epidermal growth factor receptor (EGFR) expression individually and in combination to classical biomarkers (HER2, ER, and PR), and its relation to tumors with triple negative profile in Tunisian breast carcinoma.

METHODS

Immunohistochemistry was used to estimate the rate expression of these receptors. Univariate and multivariate analyses were used to explore the prognostic significance of EGFR in this study.

RESULTS

The expression rate of EGFR was 28.6%. EGFR expression was inversely correlated to that of ER (P < 0.001). Significant correlations between the expression of EGFR and the high histological Scarff-Bloom-Richardson (SBR) grade (P = 0.038) and also with tumors size (P = 0.041) were observed. The triple negative profile (TN: ER-/PR-/HER2-) was present in 17.3% of cases. EGFR overexpression was positively associated with this clinical aggressive profile (P < 0.001). Survival analysis showed that EGFR expression was associated with poor survival of patients (P = 0.004). In multivariate analysis, EGFR expression (P = 0.035) was found to be independent prognostic factors (significantly correlated to survival).

CONCLUSION

EGFR overexpression was observed in 28.6% of Tunisian breast carcinoma, associated with unfavorable prognosis and with triple negative tumors. Systemically evaluation of EGFR in breast carcinoma could benefit especially to TN subgroup from EGFR targeting agents.

Continuous inhibition of epidermal growth factor receptor phosphorylation by erlotinib enhances antitumor activity of chemotherapy in erlotinib-resistant tumor xenografts

Erlotinib, an epidermal growth factor receptor tyrosine kinase inhibitor, has been shown to have benefits for non-small cell lung cancer and pancreatic cancer patients; however, almost all patients develop progressive disease during the therapy. On the other hand, it has been reported that a tumor continues to express epidermal growth factor receptor even after developing progressive disease. To demonstrate the clinical relevance of erlotinib treatment after progressive disease, we investigated whether continuous administration of erlotinib in combination with chemotherapy has a useful effect on progressive disease development during erlotinib treatment. For this purpose, we examined the antitumor effect of a combination therapy of a chemotherapeutic agent with erlotinib using two types of erlotinib-resistant tumor xenograft models: a non-small cell lung cancer model, in which EBC-1, H1975 and HCC827TR3 tumors were implanted, and an HPAC pancreatic cancer cell xenograft which generates erlotinib-resistant tumors in vivo. As a result, the combination therapy showed a significantly higher antitumor activity compared with chemomonotherapy in all xenograft models except the H1975 xenografts. Furthermore, erlotinib alone suppressed the phosphorylation of epidermal growth factor receptor in HPAC tumors and the two non-small cell lung cancer cell lines other than H1975. Therefore, combination therapy which uses erlotinib can be considered effective if epidermal growth factor receptor phosphorylation is inhibited by erlotinib, even in erlotinib-resistant tumor xenograft models. Our results suggest that the continuous inhibition of epidermal growth factor receptor phosphorylation by erlotinib after progressive disease enhances the antitumor activity of chemotherapy.

MK-2206, a novel allosteric inhibitor of Akt, synergizes with gefitinib against malignant glioma via modulating both autophagy and apoptosis

Gefitinib, a small molecule inhibitor of the epidermal growth factor receptor tyrosine kinase, has been shown to induce autophagy as well as apoptosis in tumor cells. Yet, how to use autophagy and apoptosis to improve therapeutic efficacy of this drug against cancer remains to be explored. We reported here that MK-2206, a potent allosteric Akt inhibitor currently in phase I trials in patients with solid tumors, could reinforce the cytocidal effect of gefitinib against glioma. We found that cotreatment with gefitinib and MK-2206 increased the cytotoxicity of this growth factor receptor inhibitor in the glioma cells, and the CompuSyn synergism/antagonism analysis showed that MK-2206 acted synergistically with gefitinib. The benefit of the combinatorial treatment was also shown in an intracranial glioma mouse model. In the presence of MK-2206, there was a significant increase in apoptosis in glioma cells treated with gefitinib. MK-2206 also augmented the autophagy-inducing effect of gefitinib, as evidenced by increased levels of the autophagy marker, LC3-II. Inhibition of autophagy by silencing of the key autophagy gene, beclin 1 or 3-MA, further increased the cytotoxicity of this combinatorial treatment, suggesting that autophagy induced by these agents plays a cytoprotective role. Notably, at 48 hours following the combinatorial treatment, the level of LC3-II began to decrease but Bim was significantly elevated, suggesting a switch from autophagy to apoptosis. On the basis of the synergistic effect of MK-2206 on gefitinib observed in this study, the combination of these two drugs may be utilized as a new therapeutic regimen for malignant glioma.

[Targeted therapies and radiation therapy in non-small cell lung cancer]

Lung cancer is the leading cause of cancer-related death. Between 80-85% of lung cancers are non-small cell lung carcinomas. One third of the patients are diagnosed with locally advanced stage. In this condition, concomitant radio-chemotherapy is the standard treatment for patients with good performance status. Despite important improvements in the last years, non-small cell lung carcinoma prognosis remains poor, with high rates of both local recurrences and metastases. The heterogeneity of molecular characteristics of non-small cell lung carcinoma cells and a better knowledge of potential targets offer promising developments for new pharmacologic agents. Hereafter we will review the currently most studied pathways and the most promising ones for the treatment of locally advanced unresectable non-small cell lung carcinoma. Two of the most attractive pathways where new agents have been developed and assessed in combination with thoracic radiotherapy or radiochemotherapy are the EGFR pathway (either with the use of monoclonal antibodies or tyrosine kinase inhibitors) and the angiogenesis inhibition. The development of targeted agents could lead to individualized therapeutic combinations taking into account the intrinsic characteristics of tumor cells. Pharmacological modulation of tumour cells radiosensitivity by targeted therapies is only starting, but yet offers promising perspectives.

HGF-independent potentiation of EGFR action by c-Met

The c-Met receptor is a potential therapeutic target for non-small cell lung cancer (NSCLC). Signaling interactions between c-Met and the mutant epidermal growth factor receptor (EGFR) have been studied extensively, but signaling intermediates and biological consequences of lateral signaling to c-Met in EGFR wild-type tumors are minimally understood. Our observations indicate that delayed c-Met activation in NSCLC cell lines is initiated by wild-type EGFR, the receptor most often found in NSCLC tumors. EGFR ligands induce accumulation of activated c-Met, which begins at 8 h and continues for 48 h. This effect is accompanied by an increase in c-Met expression and phosphorylation of critical c-Met tyrosine residues without activation of mitogen-activated protein kinase (MAPK) or Akt. Gene transcription is required for delayed c-Met activation; however, phosphorylation of c-Met by EGFR occurs without production of hepatocyte growth factor (HGF) or another secreted factor, supporting a ligand-independent mechanism. Lateral signaling is blocked by two selective c-Met tyrosine kinase inhibitors (TKIs), PF2341066 and SU11274, or with gefitinib, an EGFR TKI, suggesting kinase activity of both receptors is required for this effect. Prolonged c-Src phosphorylation is observed, and c-Src pathway is essential for EGFR to c-Met communication. Pretreatment with pan-Src family kinase inhibitors, PP2 and dasatinib, abolishes delayed c-Met phosphorylation. A c-Src dominant-negative construct reduces EGF-induced c-Met phosphorylation compared with control, further confirming a c-Src requirement. Inhibition of c-Met with PF2341066 and siRNA decreases EGF-induced phenotypes of invasion by ~86% and motility by ~81%, suggesting that a novel form of c-Met activation is utilized by EGFR to maximize these biological effects. Combined targeting of c-Met and EGFR leads to increased xenograft antitumor activity, demonstrating that inhibition of downstream and lateral signaling from the EGFR-c-Src-c-Met axis might be effective in treatment of NSCLC.

Metabolic stability of 6,7-dialkoxy-4-(2-, 3- and 4-[18F]fluoroanilino)quinazolines, potential EGFR imaging probes

Epidermal growth factor receptors (EGFR), upregulated in many tumor types, have been a target for therapeutic development and molecular imaging. The objective of this study was to evaluate the distribution and metabolic characteristics of fluorine-18 labeled anilinoquinazolines as potential imaging agents for EGFR tyrosine kinase expression. Fluorine-18 labeled fluoronitrobenzenes were prepared by reaction of potassium cryptand [(18)F]fluoride with 1,2- and 1,4-dinitrobenzenes, and 3-nitro-N,N,N-trimethylanilinium triflate in 5min. Decay-corrected radiochemical yields of [(18)F]fluoride incorporation into the nitro-aromatic compounds were 81±2%, 44±4% and 77±5% (n=3-5) for the 2-, 3- and 4-fluoro isomers, respectively. Sodium borohydride reduction to the corresponding [(18)F]fluoroanilines was achieved with greater than 80% conversion in 5min. Coupling of [(18)F]fluoroaniline-hydrochlorides to 6,7-dimethoxy-4-chloro-quinazoline gave the corresponding 6,7-dimethoxy-4-(2-, 3- and 4-[(18)F]fluoroanilino)quinazolines in 31±5%, 17±2% and 55±2% radiochemical yield, respectively, while coupling to the 6,7-diethoxy-4-chloro-quinazoline produced 6,7-diethoxy-4-(2-, 3- and 4-[(18)F]fluoroanilino)quinazolines in 19±6%, 9±3% and 36±6% radiochemical yield, respectively, in 90min to end of synthesis from [(18)F]fluoride. Biodistribution of 2- and 4-[(18)F]fluoroanilinoquinazolines was conducted in tumor-bearing mice (MDA-MB-435 and MDA-MB-468 xenografts). Low tumor uptake (<1% injected dose per gram (ID/g) of tissue up to 3h postinjection of the radiotracers) was observed. High bone uptake (5-15% ID/g) was noted with the 4-[(18)F]fluoroanilinoquinazolines. The metabolic stabilities of radiolabeled quinazolines were further evaluated by incubation with human female cryopreserved isolated hepatocytes. Rapid degeneration of the 4-fluoro-substituted compounds to baseline polar metabolites was observed by radio-TLC, whereas, the 2- and 3-[(18)F]fluoroaniline derivatives were significantly more stable, up to 2h, corroborating the in vivo biodistribution studies. para-Substituted [(18)F]fluoroanilines, a common structural motif in radiopharmaceuticals, are highly susceptible to metabolic degradation.

HDAC inhibition decreases the expression of EGFR in colorectal cancer cells

Epidermal growth factor receptor (EGFR), a receptor tyrosine kinase which promotes cell proliferation and survival, is abnormally overexpressed in numerous tumors of epithelial origin, including colorectal cancer (CRC). EGFR monoclonal antibodies have been shown to increase the median survival and are approved for the treatment of colorectal cancer. Histone deacetylases (HDACs), frequently overexpressed in colorectal cancer and several malignancies, are another attractive targets for cancer therapy. Several inhibitors of HDACs (HDACi) are developed and exhibit powerful antitumor abilities. In this study, human colorectal cancer cells treated with HDACi exhibited reduced EGFR expression, thereby disturbed EGF-induced ERK and Akt phosphorylation. HDACi also decreased the expression of SGLT1, an active glucose transporter found to be stabilized by EGFR, and suppressed the glucose uptake of cancer cells. HDACi suppressed the transcription of EGFR and class I HDACs were proved to be involved in this event. Chromatin immunoprecipitation analysis showed that HDACi caused the dissociation of SP1, HDAC3 and CBP from EGFR promoter. Our data suggested that HDACi could serve as a single agent to block both EGFR and HDAC, and may bring more benefits to the development of CRC therapy.

Combination of radiotherapy and targeted therapies in the treatment of locally advanced non-small cell lung cancer

Lung cancer is the most common cancer in the world. One third of patients with non-small cell lung cancer (NSCLC) are diagnosed with locally or regionally advanced unresectable disease at presentation. Currently, in this stage of disease, a combination of chemotherapy and radiotherapy is the standard treatment approach for patients with good performance status, and concomitant chemo-radiotherapy has demonstrated to be the best therapeutic approach. However, despite improvements in treatment, local tumor control remains suboptimal and distant metastases remain the major site of failure. The diversity of molecular abnormalities in NSCLC may partly contribute to its resistance to therapy. It is therefore widely accepted that one approach to improve the efficacy of cancer therapy is the development of rational combinations of anticancer agents that may exhibit synergistic interactions. The introduction of several biologic agents represents an important advance in the management of NSCLC and some of them have shown to have a synergistic effect when given in combination with radiotherapy and chemotherapy in preclinical and in clinical models. In the present review we discuss the rationale and the feasibility of these combinations and the first results available from clinical trials.

MicroRNA regulation of growth factor receptor signaling in human cancer cells

Aberrant expression of the epidermal growth factor receptor (EGFR) and/or human epidermal growth factor receptor 2 (HER2) is a feature of many human tumors and is associated with disease progression, treatment resistance, and poor prognosis. Protein kinase B/Akt, an important downstream effector of these receptor tyrosine kinases, induces signaling pathways that control cancer cell proliferation, invasion, angiogenesis, and apoptosis resistance. MicroRNAs (miRNAs), small noncoding RNAs that bind to the 3'-untranslated region of target mRNAs, are now recognized to play key roles in the regulation of gene expression, particularly in tumor development and metastasis. We have shown that miRNA-7 (miR-7) and miRNA-331-3p (miR-331-3p) directly regulate expression of EGFR and HER2, respectively, in glioblastoma and prostate cancer cell lines. As a consequence, miR-7 and miR-331-3p reduce Akt activity and thus have the capacity to regulate a signaling pathway critical to the development and progression of glioblastoma and prostate cancer. This chapter provides a detailed approach outlining how to confirm that a putative target of a miRNA is a direct target, and subsequent assessment of downstream signaling mediators.

Targeting epidermal growth factor receptor in the treatment of non-small-cell lung cancer

IMPORTANCE OF THE FIELD

The management of non-small-cell lung cancer (NSCLC) has undergone a paradigm shift in the last decade, with the survival advantage demonstrated by the incorporation of anti-epidermal growth factor receptor (EGFR) agents to the standard treatment of advanced/metastatic NSCLC.

AREAS COVERED IN THIS REVIEW

We review the existing data regarding the distinct anti-EGFR agents in the NSCLC treatment and the potential role of the investigated biomarkers in the clinical outcome.

WHAT THE READER WILL GAIN

Tyrosine kinase inhibitors have been used in first-line, second-line and more settings with extremely good results in a subgroup of patients. Cetuximab remains the only anti-EGFR monoclonal antibody to show survival benefit when combined with a cytotoxic agent in the front-line setting. Anti-EGFR treatment is associated with a dramatic clinical benefit in a subgroup of patients, emphasizing the importance of customizing treatment. Several biomarkers have been investigated for their predictive or prognostic value. Validation of identification of biomarkers remains a focus of intense research that may ultimately guide therapeutic decision making, as none of these is considered ideal to discriminate responding from non-responding patients. However, the current evidence of the EGFR mutation analysis from a recent randomised trial suggests that EGFR mutation analysis is quite a good predictive marker for responsiveness to anti-EGFR TKIs. Moreover, the identification of surrogate markers to indicate optimal activity of the anti-EGFR agent is also needed. This review article provides data from large clinical trials using anti-EGFR agents and correlates these results with the tested biomarkers.

TAKE HOME MESSAGE

EGFR inhibition has shown very encouraging results and has improved the outcome of the NSCLC treatment. However, a plateau of significant clinical benefit seems to have been reached and we believe that the time to move away from the traditional treatment approach to more individualizing therapies has come.