ErbBs in lung cancer

HER3 receptor and its role in the therapeutic management of metastatic breast cancer

Metastatic breast cancer (mBC) poses a significant threat to women's health and is a major cause of malignant neoplasms in women. Human epidermal growth factor receptor (HER)3, an integral member of the ErbB/HER receptor tyrosine kinase family, is a crucial activator of the phosphoinositide-3 kinase/protein kinase B signaling pathway. HER3 overexpression significantly contributes to the development of resistance to drugs targeting other HER receptors, such as HER2 and epidermal growth factor receptors, and plays a crucial role in the onset and progression of mBC. Recently, numerous HER3-targeted therapeutic agents, such as monoclonal antibodies (mAbs), bispecific antibodies (bAbs), and antibody-drug conjugates (ADCs), have emerged. However, the efficacy of HER3-targeted mAbs and bAbs is limited when used individually, and their combination may result in toxic adverse effects. On the other hand, ADCs are cytotoxic to cancer cells and can bind to target cells through antibodies, which highlights their use in targeted HER3 therapy for mBC. This review provides an overview of recent advancements in HER3 research, historical initiatives, and innovative approaches in targeted HER3 therapy for metastatic breast cancer. Evaluating the advantages and disadvantages of current methods may yield valuable insights and lessons.

To Investigate Growth Factor Receptor Targets and Generate Cancer Targeting Inhibitors

Receptor tyrosine kinase (RTK) regulates multiple pathways, including Mitogenactivated protein kinases (MAPKs), PI3/AKT, JAK/STAT pathway, etc. which has a significant role in the progression and metastasis of tumor. As RTK activation regulates numerous essential bodily processes, including cell proliferation and division, RTK dysregulation has been identified in many types of cancers. Targeting RTK is a significant challenge in cancer due to the abnormal upregulation and downregulation of RTK receptors subfamily EGFR, FGFR, PDGFR, VEGFR, and HGFR in the progression of cancer, which is governed by multiple RTK receptor signalling pathways and impacts treatment response and disease progression. In this review, an extensive focus has been carried out on the normal and abnormal signalling pathways of EGFR, FGFR, PDGFR, VEGFR, and HGFR and their association with cancer initiation and progression. These are explored as potential therapeutic cancer targets and therefore, the inhibitors were evaluated alone and merged with additional therapies in clinical trials aimed at combating global cancer.

The Role of ERBB Signaling Pathway-Related Genes in Kidney Renal Clear Cell Carcinoma and Establishing a Prognostic Risk Assessment Model for Patients

Objective: We aimed to investigate the potential role of ERBB signaling pathway–related genes in kidney renal clear cell carcinoma (KIRC) and establish a new predictive risk model using various bioinformatics methods.

Methods: We downloaded the KIRC dataset and clinicopathological information from The Cancer Genome Atlas database. Univariate Cox analysis was used to identify essential genes significantly associated with KIRC progression. Next, we used the STRING website to construct a protein–protein interaction network of ERBB signaling pathway–related molecules. We then used the least the absolute shrinkage and selection operator (LASSO) regression analysis to build a predictive risk model for KIRC patients. Next, we used multiple bioinformatics methods to analyze the copy number variation, single-nucleotide variation, and overall survival of these risk model genes in pan-cancer. At last, we used the Genomics of Drug Sensitivity in Cancer to investigate the correlation between the mRNA expression of genes associated with this risk model gene and drug sensitivity.

Results: Through the LASSO regression analysis, we constructed a novel KIRC prognosis–related risk model using 12 genes: SHC1, GAB1, SOS2, SRC, AKT3, EREG, EIF4EBP1, ERBB3, MAPK3, transforming growth factor-alpha, CDKN1A, and PIK3CD. Based on this risk model, the overall survival rate of KIRC patients in the low-risk group was significantly higher than that in the high-risk group (p = 1.221 × 10⁻¹⁵). Furthermore, this risk model was associated with cancer metastasis, tumor size, node, stage, grade, sex, and fustat in KIRC patients. The receiver operating characteristic curve results showed that the model had better prediction accuracy. Multivariate Cox regression analysis showed that the model’s risk score was an independent risk factor for KIRC. The Human Protein Atlas database was used to validate the protein expression of risk model–associated molecules in tumors and adjacent normal tissues. The validation results were consistent with our previous findings.

Conclusions: We successfully established a prognostic-related risk model for KIRC, which will provide clinicians with a helpful reference for future disease diagnosis and treatment.

The Role of EREG/EGFR Pathway in Tumor Progression

Aberrant activation of the epidermal growth factor receptor (EGFR/ERBB1) by erythroblastic leukemia viral oncogene homolog (ERBB) ligands contributes to various tumor malignancies, including lung cancer and colorectal cancer (CRC). Epiregulin (EREG) is one of the EGFR ligands and is low expressed in most normal tissues. Elevated EREG in various cancers mainly activates EGFR signaling pathways and promotes cancer progression. Notably, a higher EREG expression level in CRC with wild-type Kirsten rat sarcoma viral oncogene homolog (KRAS) is related to better efficacy of therapeutic treatment. By contrast, the resistance of anti-EGFR therapy in CRC was driven by low EREG expression, aberrant genetic mutation and signal pathway alterations. Additionally, EREG overexpression in non-small cell lung cancer (NSCLC) is anticipated to be a therapeutic target for EGFR-tyrosine kinase inhibitor (EGFR-TKI). However, recent findings indicate that EREG derived from macrophages promotes NSCLC cell resistance to EGFR-TKI treatment. The emerging events of EREG-mediated tumor promotion signals are generated by autocrine and paracrine loops that arise from tumor epithelial cells, fibroblasts, and macrophages in the tumor microenvironment (TME). The TME is a crucial element for the development of various cancer types and drug resistance. The regulation of EREG/EGFR pathways depends on distinct oncogenic driver mutations and cell contexts that allows specific pharmacological targeting alone or combinational treatment for tailored therapy. Novel strategies targeting EREG/EGFR, tumor-associated macrophages, and alternative activation oncoproteins are under development or undergoing clinical trials. In this review, we summarize the clinical outcomes of EREG expression and the interaction of this ligand in the TME. The EREG/EGFR pathway may be a potential target and may be combined with other driver mutation targets to combat specific cancers.

Conventional Transbronchial Needle Aspiration (cTBNA) and EBUS-Guided Transbronchial Needle Aspiration (EBUS-TBNA): A Retrospective Study on the Comparison of the Two Methods for Diagnostic Adequacy in Molecular Analysis

Introduction: In recent years, there has been a growing development of molecularly targeted therapies for various types of solid tumors—in particular, in non-small-cell lung cancer (NSCLC). This has required the need for greater quantities of tissue that is able to support ancillary studies, alongside cyto-histological diagnoses for the assessment of molecular targets. Conventional TBNA (cTBNA) and EBUS-guided TBNA (EBUS-TBNA) have shown a high diagnostic yield for malignant mediastinal and/or hilar lymph node enlargement and peribronchial masses; however, few studies have compared these two procedures. We retrospectively compared TBNA patients (EBUS-TBNA and cTBNA) in order to determine the diagnostic yield and material adequacy for subsequent ancillary analyses. Materials and Methods: We retrospectively evaluated 318 patients with clinical suspicion of lung cancer or with disease recurrence. All of the patients underwent TBNA (either EBUS-TBNA or cTBNA) on enlarged mediastinal and/or hilar lymph nodes and peribronchial masses between January 2017 and June 2021 at the University Hospital of Pisa, Italy. After a definitive diagnosis, molecular analyses and an evaluation of PD-L1 expression were performed in the cases of adenocarcinoma, squamous cell carcinoma, and NSCLC, not otherwise specified (NOS). Results: EBUS-TBNA was performed in 199 patients and cTBNA was performed in 119 patients with 374 and 142 lymph nodes, respectively. The overall diagnostic yield for positive diagnoses was 59% (diagnostic rate of 61% in EBUS-TBNA, and 55% in cTBNA). Adenocarcinoma (ADC) was the most frequent diagnosis in both methods. EBUS-TBNA diagnostic adequacy was 72% for molecular analysis, while it was 55.5% for cTBNA, showing a statistical trend (p = 0.08) towards the significance of EBUS. The average percentage of neoplastic cells was also statistically different between the two methods (p = 0.05), reaching 51.19 ± 22.14 in EBUS-TBNA and 45.25 ± 22.84 in cTBNA. With regard to the PD-L1 protein expression, the percentage of positivity was similar in both procedures (86% in EBUS-TBNA, 85% in cTBNA). Conclusions: Conventional TBNA (cTBNA) and EBUS-guided TBNA (EBUS-TBNA) are minimally invasive diagnostic methods that are associated with a high diagnostic yield. However, EBUS-TBNA has an improved diagnostic adequacy for molecular analysis compared to cTBNA, and is associated with a higher average percentage of neoplastic cells.

Antitumour immunity regulated by aberrant ERBB family signalling

Aberrant signalling of ERBB family members plays an important role in tumorigenesis and in the escape from antitumour immunity in multiple malignancies. Molecular-targeted agents against these signalling pathways exhibit robust clinical efficacy, but patients inevitably experience acquired resistance to these molecular-targeted therapies. Although cancer immunotherapies, including immune checkpoint inhibitors (ICIs), have shown durable antitumour response in a subset of the treated patients in multiple cancer types, clinical efficacy is limited in cancers harbouring activating gene alterations of ERBB family members. In particular, ICI treatment of patients with non-small cell lung cancers with epidermal growth factor receptor (EGFR) alterations and breast cancers with HER2 alterations failed to show clinical benefits, suggesting that EGFR and HER2 signalling may have an essential role in inhibiting antitumour immune responses. Here, we discuss the mechanisms by which the signalling of ERBB family members affects not only autonomous cancer hallmarks, such as uncontrolled cell proliferation, but also antitumour immune responses in the tumour microenvironment and the potential application of immune-genome precision medicine into immunotherapy and molecular-targeted therapy focusing on the signalling of ERBB family members.

Sialidase Attenuates Epidermal Growth Factor Response and Abolishes Antiproliferative Effects of Erlotinib in A549Alveolar Epithelial Cells

Erlotinib is a widely used, reversible tyrosine kinase inhibitor (TKI), targeting pro-proliferative signaling of epidermal growth factor receptor (EGFR). The drug is approved for the first-line treatment of patients with metastatic non-small cell lung cancer with EGFR mutations. Extracellular glycans can affect EGFR expression, dimerization, phosphorylation, and EGF binding. In this study we investigated the effects of EGF and erlotinib on the cell cycle of naive and sialidase (alpha-neuraminidase)-pretreated human A549 alveolar epithelial cells. A549 cells were labeled with propidium iodide, and fractions of cells in different phases of cycle were quantified by flow cytometry. We found that neither did desialilation nor EGF, as well as erlotinib treatment, increase the number of damaged cells (subG0/G1 cell fraction), while erlotinib did significantly increase the number of G0/G1 cells and decrease S + G2/M cell fractions. In naive cells, EGF increased proliferating cell numbers by more than 40%, and this effect was blocked by erlotinib. In desialylated cells, however, proliferation was significantly decreased by about 29%, and EGF and erlotinib did not exert significant effects. We conclude that changes in alveolar epithelial cell membrane glycosylation may affect function of growth-promoting receptors and erlotinib effectiveness.

A conformational sensor based on genetic code expansion reveals an autocatalytic component in EGFR activation

Epidermal growth factor receptor (EGFR) activation by growth factors (GFs) relies on dimerization and allosteric activation of its intrinsic kinase activity, resulting in trans-phosphorylation of tyrosines on its C-terminal tail. While structural and biochemical studies identified this EGF-induced allosteric activation, imaging collective EGFR activation in cells and molecular dynamics simulations pointed at additional catalytic EGFR activation mechanisms. To gain more insight into EGFR activation mechanisms in living cells, we develop a Förster resonance energy transfer (FRET)-based conformational EGFR indicator (CONEGI) using genetic code expansion that reports on conformational transitions in the EGFR activation loop. Comparing conformational transitions, self-association and auto-phosphorylation of CONEGI and its Y845F mutant reveals that Y₈₄₅ phosphorylation induces a catalytically active conformation in EGFR monomers. This conformational transition depends on EGFR kinase activity and auto-phosphorylation on its C-terminal tail, generating a looped causality that leads to autocatalytic amplification of EGFR phosphorylation at low EGF dose.

Upon ligand binding epidermal growth factor receptor (EGFR) dimerizes and activates its intrinsic kinase to auto-phosphorylate EGFR. Here, the authors engineer and image a FRET-based conformational EGFR indicator which reveals that activation loop phosphorylation induces a catalytically active conformation in EGFR monomers.

miR-152 is involved in the proliferation and metastasis of ovarian cancer through repression of ERBB3

MicroRNAs (miRNAs) participate in post-transcriptional regulation by targeting the 3' untranslated region of target genes that are involved in diverse biological processes. To the best of our knowledge, the association between miR‑152 and ERBB3 in ovarian cancer remains unclear. In the present study, a negative correlation between miR‑152 and ERBB3 in ovarian cancer was observed. The luciferase reporter gene assay results demonstrated that miR‑152 negatively regulated ERBB3 in SKOV3 and OVCAR3 ovarian cancer cells. Furthermore, our results revealed that miR‑152 suppressed the ability of ovarian cancer cell proliferation, migration and invasion, and promoted apoptosis through inhibiting ERBB3 in vitro. Therefore, in the present study, miR‑152 was found to be involved in the proliferation and metastasis of ovarian cancer cells through repression of ERBB3 expression. Therefore, miR‑152 may be a potential therapeutic target for the treatment of ovarian cancer.

Organotypic three-dimensional cancer cell cultures mirror drug responses in vivo: lessons learned from the inhibition of EGFR signaling

Complex three-dimensional (3D) in vitro models that recapitulate human tumor biology are essential to understand the pathophysiology of the disease and to aid in the discovery of novel anti-cancer therapies. 3D organotypic cultures exhibit intercellular communication, nutrient and oxygen gradients, and cell polarity that is lacking in two-dimensional (2D) monolayer cultures. In the present study, we demonstrate that 2D and 3D cancer models exhibit different drug sensitivities towards both targeted inhibitors of EGFR signaling and broad acting cytotoxic agents. Changes in the kinase activities of ErbB family members and differential expression of apoptosis- and survival-associated genes before and after drug treatment may account for the differential drug sensitivities. Importantly, EGFR oncoprotein addiction was evident only in the 3D cultures mirroring the effect of EGFR inhibition in the clinic. Furthermore, targeted drug efficacy was strongly increased when incorporating cancer-associated fibroblasts into the 3D cultures. Taken together, we provide conclusive evidence that complex 3D cultures are more predictive of the clinical outcome than their 2D counterparts. In the future, 3D cultures will be instrumental for understanding the mode of action of drugs, identifying genotype-drug response relationships and developing patient-specific and personalized cancer treatments.

Endobronchial ultrasound guided transbronchial needle aspiration combining with immunohistochemistry and genotype in lung cancer: A single-center, 55 cases retrospective study

OBJECTIVE

The purpose of this study was to evaluate the utility of EBUS-TNA for mediastinal mass or suspected lung cancer patients with mediastinal or hilar lymph node enlarged. Further to investigate the clinical value of EBUS-TBNA combining with immunohistochemistry and genotype in lung cancer.

METHODS

A total of 55 patients with mediastinal, and/or hilar lymphadenopathy, and/or mediastinal mass previously detected by CT or PET/CT scan and who underwent EBUS-TBNA. An additional immunohistological analysis was performed for establishing a reliable diagnosis and sub classification when necessary. Some samples were tested for the EGFR and/or ALK mutations to provide suitable mutational genotyping for adenocarcinoma by using the PCR assays.

RESULTS

Of the 55 patients, the sensitivity and diagnostic accuracy of EBUS-TBNA in the diagnosis of lung cancer were 92.5% (37/40) and 94.5% (52/55), respectively. 37 samples were further confirmed and obtained particular type by Immunohistochemistry. 6 cases of EBUS-TBNA samples from patients with lung adenocarcinoma referred for EGFR testing were analyzed, 4 patients were found to have EGFR gene mutations. The procedure was uneventful without any complications.

CONCLUSION

EBUS-TBNA is a safe and efficient method with high sensitivity and specificity in the diagnosis of lung cancer. Uniquely combining with Immunohistochemistry and molecular testing has significant clinical value in subtype diagnosis and guiding the treatment strategy in lung cancer.

ErbB Family Signalling: A Paradigm for Oncogene Addiction and Personalized Oncology

ErbB family members represent important biomarkers and drug targets for modern precision therapy. They have gained considerable importance as paradigms for oncoprotein addiction and personalized medicine. This review summarizes the current understanding of ErbB proteins in cell signalling and cancer and describes the molecular rationale of prominent cases of ErbB oncoprotein addiction in different cancer types. In addition, we have highlighted experimental technologies for the development of innovative cancer cell models that accurately predicted clinical ErbB drug efficacies. In the future, such cancer models might facilitate the identification and validation of physiologically relevant novel forms of oncoprotein and non-oncoprotein addiction or synthetic lethality. The identification of genotype-drug response relationships will further advance personalized oncology and improve drug efficacy in the clinic. Finally, we review the most important drugs targeting ErbB family members that are under investigation in clinical trials or that made their way already into clinical routine. Taken together, the functional characterization of ErbB oncoproteins have significantly increased our knowledge on predictive biomarkers, oncoprotein addiction and patient stratification and treatment.

Next-generation sequencing of non-small cell lung cancer using a customized, targeted sequencing panel: Emphasis on small biopsy and cytology

Background:

Next-generation sequencing (NGS) with a multi-gene panel is now available for patients with lung adenocarcinoma, but the performance characteristics and clinical utility of this testing are not well-described. We present the results of an extended 467 gene panel in a series of advanced, highly selected nonsmall cell lung cancer (NSCLC) patients using a range of specimens, including predominantly small biopsy and cytology specimens.

Materials and Methods:

A retrospective review of 22 NSCLC biopsies sent for NGS using an extended gene panel from January 2014 to July 2015. The customized NGS panel sequences 467 cancer-associated genes with exonic and intronic sequences obtained from purified tumor DNA. Genomic alterations, patient characteristics, and success of testing were determined.

Results:

The majority of samples tested were metastatic lung adenocarcinoma on final pathology. Of the 22 specimens tested, 5 (22.7%) were surgical resections and 17 (77.3%) were small biopsy and cytology specimens. Twenty-one (95%) of the specimens were adequate for full sequencing and yielded a total of 204 genomic alterations (average 8.9 per tumor), of which 17 (average 0.81 per tumor) were actionable and/or clinically relevant. Genomic alterations were found most commonly in the TP53, EGFR, EPHB1, MLL3, APC, SETD2, KRAS, DNMT3A, RB1, CDKN2A, ARID1A, EP300, KDM6B, RAD50, STK11, and BRCA2 genes.

Conclusions:

NGS using a comprehensive gene panel was performed successfully in 95% of all NSCLC cases in this series, including 94% small biopsy and cytology specimens and 100% surgical resections. This custom assay was performed on a range of tumor specimens and demonstrates that small specimens are able to provide a similar depth of information as larger ones. As many patients present at an advanced stage and only small specimens are obtained, the information these provide has the potential for guiding treatment in highly selected patients with advanced lung adenocarcinoma.

Identification of a novel HER3 activating mutation homologous to EGFR-L858R in lung cancer

Somatic mutations found within the tyrosine kinase domain (TKD) of the human epidermal growth factor (HER) family of receptors have been implicated in the development and progression of non-small cell lung cancer (NSCLC). However, no conclusive reports have described pathogenic mutations in kinase-impaired HER3. Here, we report a case of an advanced chemotherapy-resistant NSCLC, harboring a novel HER3^V855A somatic mutation homologous to the EGFR^L858Ractivating mutation. Co-expression of HER3^V855A and wild-type HER2 enhances ligand-induced transformation of murine and human cell lines, while HER-targeted inhibitors potently suppress mutant HER3 activity. Consistent with these observations, in silico computational modeling predicts that mutant V855A alters the kinase domain and c-terminal end of the HER3 protein. Taken together, these findings provide a basis for the clinical exploration of targeted therapies in HER3 mutant NSCLC and by extrapolation, in other cancers that more frequently carry somatic HER3 mutations.

A Histopathological Feature of EGFR-Mutated Lung Adenocarcinomas with Highly Malignant Potential - An Implication of Micropapillary Element

The purpose of this study was to define histological features determining the malignant potential of EGFR-mutated lung adenocarcinoma (LADC). Surgically resected tumors (EGFR-mutated LADCs with (21) and without (79) lymph node metastasis and EGFR wild-type LADCs with (26) and without (108) lymph node metastasis) and biopsy samples from inoperably advanced tumors (EGFR-mutated LADCs (78) and EGFR wild-type LADCs (99)) were examined. In surgically resected tumors, the EGFR-mutated LADCs with lymph node metastasis had the micropapillary element in a significantly greater proportion than others (Mann-Whitney tests P ≤0.026). The proportion of micropapillary element was higher in the EGFR-mutated LADC at the advanced stage (stage II, III, or IV) than in the tumor at the early stage (stage I) (Mann-Whitney test, P<0.0001). In the biopsy samples from inoperably advanced LADCs (177), EGFR-mutated tumors also had micropapillary element at a higher frequency than EGFR-wild type tumors (53/78 (68%), versus 30/99 (30%), Pearson x2 test, P<0.0001). In stage I EGFR-mutated LADCs (84), the tumors with the micropapillary element (34) exhibited a significantly higher recurrence rate than tumors without micropapillary element (50) (5-year Recurrence-free survival 64.4% versus 93.3%, log-rank test P = 0.028). The micropapillary element may be an exclusive determinant of malignant potential in EGFR-mutated LADC. It is suggested that EGFR-mutated LADC may develop through a distinct histogenesis, in which the micropapillary element is important for promoting progression.

Dual targeting of HER3 and MEK may overcome HER3-dependent drug-resistance of colon cancers

Although the medical treatment of colorectal cancer has evolved greatly in the last years, a significant portion of early-stage patients develops recurrence after therapies. The current clinical trials are directed to evaluate new drug combinations and treatment schedules.

By the use of patient-derived or established colon cancer cell lines, we found that the tyrosine kinase receptor HER3 is involved in the mechanisms of resistance to therapies. In agreement, the immunohistochemical analysis of total and phospho-HER3 expression in 185 colorectal cancer specimens revealed a significant correlation with lower disease-free survival.

Targeting HER3 by the use of the monoclonal antibody patritumab we found induction of growth arrest in all cell lines. Despite the high efficiency of patritumab in abrogating the HER3-dependent activation of PI3K pathway, the HER2 and EGFR-dependent MAPK pathway is activated as a compensatory mechanism. Interestingly, we found that the MEK-inhibitor trametinib inhibits, as expected, the MAPK pathway but induces the HER3-dependent activation of PI3K pathway. The combined treatment results in the abrogation of both PI3K and MAPK pathways and in a significant reduction of cell proliferation and survival.

These data suggest a new strategy of therapy for HER3-overexpressing colon cancers.

Yield and Clinical Utility of Next-Generation Sequencing in Selected Patients With Lung Adenocarcinoma

BACKGROUND

Next-generation sequencing is available for assessing genomic alterations in non-small-cell lung cancer (NSCLC), although the performance characteristics and clinical utility has not been well characterized. This technique can be used to sequence hundreds of known cancer-associated genes. Our aim was to investigate the diagnostic success and clinically relevant results of extensive sequencing in NSCLC patients.

PATIENTS AND METHODS

A case series of 49 NSCLC patients was used to determine the success of extended next-generation sequencing, record genomic alterations, and evaluate clinical utility. Data were collected in a retrospective review. Sequencing was performed using a hybridization capture of 3320 exons from 236 cancer-related genes and 47 introns of 19 genes applied to ≥50 ng of DNA and sequenced to high, uniform coverage of 622 times.

RESULTS

Sequencing was successful in 29 of 32 (91%) surgical/excisional specimens, and 12 of 17 (71%) nonsurgical specimens including an endoscopic forceps biopsy, core needle biopsies, fine-needle aspirates, and effusion cytologies. All 5 transthoracic core needle biopsies failed. A total of 179 genomic alterations (average 4.37 per tumor) were found. A total of 63 were clinically relevant (average 1.54 per tumor). The most frequently mutated genes were tumor protein p53, cyclin-dependent kinase inhibitor 2A, megalencephalic leukoencephalopathy with subcortical cysts 1, rapamycin-insensitive companion of mammalian target of rapamycin, epithelial growth factor receptor, SWI/SNF Related, Matrix Associated, Actin Dependent Regulator Of Chromatin, Subfamily A, Member 4, cyclin-dependent kinase inhibitor 2B, phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit α, Kirsten rat sarcoma viral oncogene homolog, Erb-B2 receptor tyrosine kinase 2, Serine/Threonine Kinase 11, and NK2 Homeobox 1. Sequencing results led to a change in management in 7 of 49 cases (14.3%).

CONCLUSION

Extended next-generation sequencing was performed successfully in 41 (83.7%) cases of NSCLC using a range of pathology specimens. Testing had the potential to affect treatment decisions in selected patients.

Comprehensive Genomic Profiling Facilitates Implementation of the National Comprehensive Cancer Network Guidelines for Lung Cancer Biomarker Testing and Identifies Patients Who May Benefit From Enrollment in Mechanism-Driven Clinical Trials

BACKGROUND

The National Comprehensive Cancer Network (NCCN) guidelines for patients with metastatic non-small cell lung cancer (NSCLC) recommend testing for EGFR, BRAF, ERBB2, and MET mutations; ALK, ROS1, and RET rearrangements; and MET amplification. We investigated the feasibility and utility of comprehensive genomic profiling (CGP), a hybrid capture-based next-generation sequencing (NGS) test, in clinical practice.

METHODS

CGP was performed to a mean coverage depth of 576× on 6,832 consecutive cases of NSCLC (2012-2015). Genomic alterations (GAs) (point mutations, small indels, copy number changes, and rearrangements) involving EGFR, ALK, BRAF, ERBB2, MET, ROS1, RET, and KRAS were recorded. We also evaluated lung adenocarcinoma (AD) cases without GAs, involving these eight genes.

RESULTS

The median age of the patients was 64 years (range: 13-88 years) and 53% were female. Among the patients studied, 4,876 (71%) harbored at least one GA involving EGFR (20%), ALK (4.1%), BRAF (5.7%), ERBB2 (6.0%), MET (5.6%), ROS1 (1.5%), RET (2.4%), or KRAS (32%). In the remaining cohort of lung AD without these known drivers, 273 cancer-related genes were altered in at least 0.1% of cases, including STK11 (21%), NF1 (13%), MYC (9.8%), RICTOR (6.4%), PIK3CA (5.4%), CDK4 (4.3%), CCND1 (4.0%), BRCA2 (2.5%), NRAS (2.3%), BRCA1 (1.7%), MAP2K1 (1.2%), HRAS (0.7%), NTRK1 (0.7%), and NTRK3 (0.2%).

CONCLUSION

CGP is practical and facilitates implementation of the NCCN guidelines for NSCLC by enabling simultaneous detection of GAs involving all seven driver oncogenes and KRAS. Furthermore, without additional tissue use or cost, CGP identifies patients with "pan-negative" lung AD who may benefit from enrollment in mechanism-driven clinical trials.

IMPLICATIONS FOR PRACTICE

National Comprehensive Cancer Network guidelines for patients with metastatic non-small cell lung cancer (NSCLC) recommend testing for several genomic alterations (GAs). The feasibility and utility of comprehensive genomic profiling were studied in NSCLC and in lung adenocarcinoma (AD) without GAs. Of patients with NSCLC, 71% harbored at least one GA to a gene listed in the guidelines or KRAS; 273 cancer-related genes were altered in at least 0.1% of the AD cases. Although logistical and administrative hurdles limit the widespread use of next-generation sequencing, the data confirm the feasibility and potential utility of comprehensive genomic profiling in clinical practice.

Fine-needle aspiration of small pulmonary nodules yields material for reliable molecular analysis of adenocarcinomas

INTRODUCTION

Early molecular characterization with Kirsten rat sarcoma factor, epidermal growth factor, and anaplastic lymphoma kinase are critical to manage pulmonary adenocarcinoma. Fine-needle aspiration (FNA) of lesions <2 cm are routine in our institution and are used in molecular analysis. We report our experience.

MATERIALS AND METHODS

We searched our databank for primary pulmonary adenocarcinomas diagnosed by FNA between January 2009 and April 2013. Size of the lesion aspirated, molecular results, and sample source (FNA versus surgical specimen) were recorded. We compared the frequency of mutations identified by FNA versus surgical specimens and the frequency of mutations in lesions by size (<1 cm, 1-2 cm, >2 cm).

RESULTS

We identified 397 primary pulmonary adenocarcinomas. Molecular studies were requested by the clinician in 89 (22%) of primary adenocarcinomas. FNAs were used in 55 cases; 51 (93%) yielded sufficient material for molecular studies; surgical tissue were used in 34 cases; 33 (97%) yielded sufficient material for molecular studies. The insufficient specimens came from 2 FNAs of 0.6 cm nodules, an FNA of a 2 cm nodule, and a core biopsy.

CONCLUSIONS

FNA was adequate for molecular analysis of small nodules. In nodules greater than 0.6 cm, the adequacy is comparable to surgical tissue. There was no statistically significant change in mutation rate by size (53%-58%). Importantly, FNA of small lesions for cytological diagnosis and molecular analysis is encouraged by our data and experience in order to provide early treatment.

Regulation of the ErbB network by the MIG6 feedback loop in physiology, tumor suppression and responses to oncogene-targeted therapeutics

The ErbB signaling network instructs the execution of key cellular programs, such as cell survival, proliferation and motility, through the generation of robust signals of defined strength and duration. In contrast, unabated ErbB signaling disrupts tissue homeostasis and leads to cell transformation. Cells oppose the threat inherent in excessive ErbB activity through several mechanisms of negative feedback regulation. Inducible feedback inhibitors (IFIs) are expressed in the context of transcriptional responses triggered by ErbB signaling, thus being uniquely suited to regulate ErbB activity during the execution of complex cellular programs. This review focuses on MIG6, an IFI that restrains ErbB signaling by mediating ErbB kinase suppression and receptor down-regulation. We will review key issues in MIG6 function, regulation and tumor suppressor activity. Subsequently, the role for MIG6 loss in the pathogenesis of tumors driven by ErbB oncogenes as well as in the generation of cellular addiction to ErbB signaling will be discussed. We will conclude by analyzing feedback inhibition by MIG6 in the context of therapies directed against ErbB and non-ErbB oncogenes.

Combined inhibition of rho-associated protein kinase and EGFR suppresses the invasive phenotype in EGFR-dependent lung cancer cells

INTRODUCTION

Lung cancer remains the leading cause of cancer-related mortality worldwide, with metastatic disease frequently a prominent feature at the time of diagnosis. The role of NSCLC-derived EGFR mutations in cancer cell proliferation and survival has been widely reported, but little is known about the function of these mutations in invasive growth and metastasis. In this study, we sought to evaluate the intrinsic invasive properties of NSCLC cells with differing EGFR status and examine possible therapeutic targets that can abrogate invasive growth.

MATERIALS AND METHODS

Collagen-based assays and 3D cell cultures were used to assess morphological features, actin cytoskeleton dynamics and the invasive capacity of NSCLC cell lines with differing EGFR status. The role of the RhoA/ROCK/MYPT1 and EGFR/HER pathways in NSCLC-related invasion was investigated by pharmacological inhibition and RNA interference techniques.

RESULTS

We demonstrate a positive correlation between EGFR mutational/amplification status and invasive capacity. Knockdown of wild-type and mutant EGFR leads to depletion of active and total MYPT1 levels. Combined pharmacological inhibition or genetic ablation of ROCK/EGFR suppresses the hallmarks of cancer cells and abrogates the invasive phenotype in EGFR-dependent NSCLC cells.

CONCLUSIONS

These observations suggest that combined targeting of the ROCK and EGFR/HER pathways may be a potential therapeutic approach in limiting invasive growth in NSCLC.

Effect of sialylation on EGFR phosphorylation and resistance to tyrosine kinase inhibition

Epidermal growth factor receptor (EGFR) is a heavily glycosylated transmembrane receptor tyrosine kinase. Upon EGF-binding, EGFR undergoes conformational changes to dimerize, resulting in kinase activation and autophosphorylation and downstream signaling. Tyrosine kinase inhibitors (TKIs) have been used to treat lung cancer by inhibiting EGFR phosphorylation. Previously, we demonstrated that EGFR sialylation suppresses its dimerization and phosphorylation. In this report, we further investigated the effect of sialylation on the phosphorylation profile of EGFR in TKI-sensitive and TKI-resistant cells. Sialylation was induced in cancer progression to inhibit the association of EGFR with EGF and the subsequent autophosphorylation. In the absence of EGF the TKI-resistant EGFR mutant (L858R/T790M) had a higher degree of sialylation and phosphorylation at Y1068, Y1086, and Y1173 than the TKI-sensitive EGFR. In addition, although sialylation in the TKI-resistant mutants suppresses EGFR tyrosine phosphorylation, with the most significant effect on the Y1173 site, the sialylation effect is not strong enough to stop cancer progression by inhibiting the phosphorylation of these three sites. These findings were supported further by the observation that the L858R/T790M EGFR mutant, when treated with sialidase or sialyltransferase inhibitor, showed an increase in tyrosine phosphorylation, and the sensitivity of the corresponding resistant lung cancer cells to gefitinib was reduced by desialylation and was enhanced by sialylation.

The diagnosis and treatment of brain metastases in EGFR mutant lung cancer

The epidemiology of non-small-cell lung cancer (NSCLC) has changed with a new pattern of disease emerging - a form of adenocarcinoma in mostly younger female patients, who are never or light smokers and more frequently in East Asian populations. Description of EGF receptor (EGFR) mutations has allowed new management strategies to evolve. Oral targeted therapies have broadened the treatment options in the advanced setting with the potential for periods of long term response. The brain is a common site of metastases with EGFR mutated lung cancer typically displaying asymptomatic, small volume, multiple lesions that respond to treatment. We explore the role of local and system therapies for brain metastases in this disease including the role of EGFR inhibitors.

Pharmacogenomics and targeted therapy of cancer: Focusing on non-small cell lung cancer

Recent studies have been established high degree of genetic diversity in solid organ tumors among individuals and even between individual tumor cells. This intratumor and intertumor genetic diversity results in a heterogeneous tumor with unique characteristics which potentially allows effective drug therapy. The goal of pharmacogenomics is to elucidate the genetic network(s) that underlie drug efficacy and drug resistance. Advances in targeted and personalized therapy play an increasingly important role in many common cancers, notably lung cancer, due to the high incidence, prevalence, mortality and the greater tendency towards drug resistance seen in these patients. Non-small cell lung cancer (NSCLC) is characterized by mutations in the epidermal growth factor receptor (EGFR) and or downstream kinase pathways. This has led to the development of highly selective monoclonal antibodies and EGFR tyrosine kinase inhibitors (EGFR-TKIs) to prevent cancer initiation, proliferation, differentiation, angiogenesis, survival, and invasion. However, resistance to many of these new treatments is induced and further pharmacogenomic analysis has revealed mutations associated with increased or reduced drug efficacy. Combinations of kinase inhibitors or potentially the targeting of cancer stem cells may further increase the success of pharmacogenomics in treating patients with lung cancer.

Met in lung cancer

Receptor tyrosine kinases play important roles in the biology of many tumor cell types. In approximately 10% of non-small cell lung cancer (NSCLC) patients mutational activation of the epidermal growth factor receptor (EGFR) results in tumor cells that are exquisitely addicted to signaling by this receptor.¹ Thus expression of mutant active EGFR but in general not wild-type EGFR predisposes NSCLC cells to inhibitors of EGFR/ErbB2. Use of EGFR inhibitory agents such as gefitinib for this subset of NSCLC patients causes tumor regression and disease stabilization for 12–18 mo, after which tumor cells become resistant to the drug.² Initial studies identified a second mutation within the EGFR, which results in the resistance of the tyrosine kinase to gefitinib, as a major cause of reduced tumor control.³ This has resulted in the development of newer EGFR inhibitors, e.g., afatinib, which inhibited double mutant EGFR.⁴ In a subset of these patients, however, resistance to gefitinib was not associated with EGFR mutations.⁵ Clearly, other mechanisms of gefitinib resistance must be at play.

Downregulation of both EGFR and ErbB3 improves the cellular response to pemetrexed in an established pemetrexed‑resistant lung adenocarcinoma A549 cell line

Epidermal growth factor receptor (EGFR) and ErbB3 (HER3) play important roles in the regulation of cell proliferation, differentiation, anti-apoptosis and chemoresistance; however, their dysregulation in pemetrexed (PEM) resistance remains unclear. The aim of the present study was to clarify the relationship between PEM resistance and gene expression of EGFR and ErbB3, by establishing the PEM-resistant lung adenocarcinoma A549 cell line, A549/PEM. Compared with A549 cells, the A549/PEM cells were significantly more resistant to PEM (P=0.0024). The downregulation of S phase and arrest at G1 stage were detected in the A549/PEM cell line when compared to the A549 cells (P<0.05). The apoptosis rate of A549/PEM cells was much lower than that of the A549 cells after a 24 h continuous exposure to PEM (P<0.001). Real-time PCR and western blotting demonstrated the overexpression of EGFR and ErbB3 in A549/PEM cells. However, downregulation of EGFR or ErbB3 by lentiviral delivered shRNAs in A549/PEM cells showed no significant correlation with PEM sensitivity while silencing both EGFR and ErbB3 increased the cellular response to PEM in the A549/PEM cells and significantly decreased phosphorylation of STAT3, AKT and ERK. Together, these data suggest that either high expression of EGFR or ErbB3 plays a critical role in the cellular response to PEM in human lung adenocarcinoma cells though EGFR/ErbB3-dependent pathways.

EV20, a Novel Anti-ErbB-3 Humanized Antibody, Promotes ErbB-3 Down-Regulation and Inhibits Tumor Growth In Vivo

ErbB-3 (HER-3) receptor is involved in tumor progression and resistance to therapy. Development of specific inhibitors impairing the activity of ErbB-3 is an attractive tool for cancer therapeutics. MP-RM-1, a murine monoclonal antibody targeting human ErbB-3, has shown anticancer activity in preclinical models. With the aim to provide novel candidates for clinical use, we have successfully generated a humanized version of MP-RM-1. The humanized antibody, named EV20, abrogates both ligand-dependent and ligand-independent receptor signaling of several tumor cell types, strongly promotes ErbB-3 down-regulation, and efficiently and rapidly internalizes into tumor cells. Furthermore, treatment with EV20 significantly inhibits growth of xenografts originating from prostatic, ovarian, and pancreatic cancers as well as melanoma in nude mice. In conclusion, we provide a novel candidate for ErbB-3-targeted cancer therapy.

Delphinidin reduces cell proliferation and induces apoptosis of non-small-cell lung cancer cells by targeting EGFR/VEGFR2 signaling pathways

Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor 2 (VEGFR2) have emerged as two effective clinical targets for non-small-cell lung cancer (NSCLC). In the present study, we found that delphinidin, an anthocyanidin, present in pigmented fruits and vegetables, is a potent inhibitor of both EGFR and VEGFR2 in NSCLC cells that overexpress EGFR/VEGFR2. Using these cells, we next determined the effects of delphinidin on cell growth and apoptosis in vitro and on tumor growth and angiogenesis in vivo. Delphinidin (5-60 µM) treatment of NSCLC cells inhibited the activation of PI3K, and phosphorylation of AKT and MAPKs. Additionally, treatment of NSCLC cells with delphinidin resulted in inhibition of cell growth without having significant toxic effects on normal human bronchial epithelial cells. Specifically, treatment of NCI-H441 and SK-MES-1 cells with delphindin (5-60 µM) resulted in (i) cleavage of PARP protein, (ii) activation of caspase-3 and -9, (iii) downregulation of anti-apoptotic proteins (Bcl2, Bcl-xL and Mcl-1), (iv) upregulation of pro-apoptotic proteins (Bax and Bak), and (v) decreased expression of PCNA and cyclin D1. Furthermore, in athymic nude mice subcutaneously implanted with human NSCLC cells, delphinidin treatment caused a (i) significant inhibition of tumor growth, (ii) decrease in the expression of markers for cell proliferation (Ki67 and PCNA) and angiogenesis (CD31 and VEGF), and (iii) induction of apoptosis, when compared with control mice. Based on these observations, we suggest that delphinidin, alone or as an adjuvant to current therapies, could be used for the management of NSCLC, especially those that overexpress EGFR and VEGFR2.

Network-based approaches for anticancer therapy (Review)

Cancer is a complex disease resulting from alterations of multiple signaling networks. Cancer networks have been identified as scale-free networks and may contain a functionally important key player called a hub that is linked to a large number of interactors. Since a hub can serve as a biological marker in a given network, targeting the hub could be an effective strategy for enhancing the efficacy of cancer treatment. Chemotherapies and radiotherapies are generally used to treat tumors not amenable to resection, and target single or multiple molecules associated with hubs. However, these therapies may unexpectedly induce the resistance of cancer cells to drugs and radiation. Cancer cells can overcome therapy-induced damage via the activation of back-up signaling pathways and flexible modulation of affected networks. These activities are considered to be the main reasons for chemoresistance and radioresistance, and subsequent failure of cancer therapies. Much effort is required to identify the key molecules that control the modulation of signaling networks in response to drugs and radiation. Network-based therapy that affects network flexibility, including rewired network structures and hub molecules in these networks, could minimize the occurrence of side-effects and be a promising strategy for enhancing the therapeutic efficacy of cancer treatments. This review is intended to offer an overview of current research efforts including ones focused on cancer-associated complex networks, their modulation in response to cancer therapy, and further strategies targeting networks that may improve cancer treatment efficacy.

The efficacy of EBUS-guided transbronchial needle aspiration for molecular testing in lung adenocarcinoma

BACKGROUND

The purpose of the study was to assess the efficacy of obtaining adequate cytologic specimens by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) for molecular testing of lung adenocarcinomas.

METHODS

This was an institutional review board-approved study of all patients who had undergone EBUS-TBNA from April 2010 through March 2012 for the diagnosis, staging, or both of lung cancer. Patients with a diagnosis of adenocarcinoma were reflexively tested for molecular markers by polymerase chain reaction, sequencing, and fluorescence in situ hybridization (FISH). All procedures were performed with patients under conscious sedation in the bronchoscopy suite.

RESULTS

Of 205 patients who underwent EBUS-TBNA, 56 patients (24 male, 32 female) had a diagnosis of adenocarcinoma warranting molecular analysis. Molecular analysis was available for epidermal growth factor receptor (EGFR), Kirsten rat sarcoma (Kras) mutation, and anaplastic lymphoma kinase (ALK) gene rearrangement. The institution's clinical protocol involved initial testing for EGFR mutation with a reflex Kras test if the EGFR test result was negative. ALK FISH molecular testing was completed if both EGFR and Kras test results were negative. A total of 52 of 56 (93%) patients had sufficient cytologic material for complete or partial molecular testing, whereas 46 of 56 (82%) patients had sufficient material for all clinically indicated testing. EGFR, Kras, and ALK analysis yielded positive results in 5 (10%), 10 (25%), and 5 (12%) tested specimens, respectively. No complications were associated with EBUS-TBNA.

CONCLUSIONS

EBUS-TBNA performed with the patient under moderate sedation can be expected to yield sufficient tissue for sequential molecular analysis in the majority of patients. In an era of targeted therapy for lung adenocarcinomas, EBUS-TBNA is effective in clinical practice for complete diagnosis, staging, and treatment planning in these patients.

Induction of apoptosis and the regulation of ErbB signaling by laminarin in HT-29 human colon cancer cells

Laminarin, found in marine brown algae, is used as a carbohydrate reserve for phytoplankton; however, it is also used in traditional Chinese medicine, and has been shown to have several biological activities, including anticancer activities. In this study, we examined the mechanisms through which laminarin from Laminaria digitata induces apoptosis in HT-29 colon cancer cells, as well as the involvement of the ErbB signaling pathway. Cell viability assay revealed that laminarin induced cell death in a dose-dependent manner. Cell cycle analysis revealed that laminarin increased the percentage of cells in the sub-G1 and G2-M phase. Western blot analysis demonstrated that laminarin inhibited the heregulin-stimulated phosphorylation of ErbB2. A decrease in cellular proliferation was also observed; this was found to be dependent on ErbB, which activates c-Jun N-terminal kinase. These findings demonstrate the important role of the epidermal growth factor receptor in colon cancer tumorigenesis, and suggest the potential of laminarin as a bio-functional food with anticancer effects on human colon cancer.

Independent of ErbB1 gene copy number, EGF stimulates migration but is not associated with cell proliferation in non-small cell lung cancer

Background

Lung cancer often exhibits molecular changes, such as the overexpression of the ErbB1 gene. ErbB1 encodes epidermal growth factor receptor (EGFR), a tyrosine kinase receptor, involved mainly in cell proliferation and survival. EGFR overexpression has been associated with more aggressive disease, poor prognosis, low survival rate and low response to therapy. ErbB1 amplification and mutation are associated with tumor development and are implicated in ineffective treatment. The aim of the present study was to investigate whether the ErbB1 copy number affects EGFR expression, cell proliferation or cell migration by comparing two different cell lines.

Methods

The copies of ErbB1 gene was evaluated by FISH. Immunofluorescence and Western blotting were performed to determine location and expression of proteins mentioned in the present study. Proliferation was studied by flow cytometry and cell migration by wound healing assay and time lapse.

Results

We investigated the activation and function of EGFR in the A549 and HK2 lung cancer cell lines, which contain 3 and 6 copies of ErbB1, respectively. The expression of EGFR was lower in the HK2 cell line. EGFR was activated after stimulation with EGF in both cell lines, but this activation did not promote differences in cellular proliferation when compared to control cells. Inhibiting EGFR with AG1478 did not modify cellular proliferation, confirming previous data. However, we observed morphological alterations, changes in microfilament organization and increased cell migration upon EGF stimulation. However, these effects did not seem to be consequence of an epithelial-mesenchymal transition.

Conclusion

EGFR expression did not appear to be associated to the ErbB1 gene copy number, and neither of these aspects appeared to affect cell proliferation. However, EGFR activation by EGF resulted in cell migration stimulation in both cell lines.

At the crossroads: EGFR and PTHrP signaling in cancer-mediated diseases of bone

The epidermal growth factor receptor is a well-established cancer therapeutic target due to its stimulation of proliferation, motility, and resistance to apoptosis. Recently, additional roles for the receptor have been identified in growth of metastases. Similar to development, metastatic spread requires signaling interactions between epithelial-derived tumor cells and mesenchymal derivatives of the microenvironment. This necessitates reactivation of developmental signaling molecules, including the hypercalcemia factor parathyroid hormone-related protein. This review covers the variations of epidermal growth factor receptor signaling in cancers that produce bone metastases, regulation of parathyroid hormone-related protein, and evidence that the two molecules drive cancer-mediated diseases of bone.

Elevated expression of Fn14 in non-small cell lung cancer correlates with activated EGFR and promotes tumor cell migration and invasion

Lung cancer is the leading cause of cancer deaths worldwide; approximately 85% of these cancers are non-small cell lung cancer (NSCLC). Patients with NSCLC frequently have tumors harboring somatic mutations in the epidermal growth factor receptor (EGFR) gene that cause constitutive receptor activation. These patients have the best clinical response to EGFR tyrosine kinase inhibitors (TKIs). Herein, we show that fibroblast growth factor-inducible 14 (Fn14; TNFRSF12A) is frequently overexpressed in NSCLC tumors, and Fn14 levels correlate with p-EGFR expression. We also report that NSCLC cell lines that contain EGFR-activating mutations show high levels of Fn14 protein expression. EGFR TKI treatment of EGFR-mutant HCC827 cells decreased Fn14 protein levels, whereas EGF stimulation of EGFR wild-type A549 cells transiently increased Fn14 expression. Furthermore, Fn14 is highly expressed in EGFR-mutant H1975 cells that also contain an EGFR TKI-resistance mutation, and high TKI doses are necessary to reduce Fn14 levels. Constructs encoding EGFRs with activating mutations induced Fn14 expression when expressed in rat lung epithelial cells. We also report that short hairpin RNA-mediated Fn14 knockdown reduced NSCLC cell migration and invasion in vitro. Finally, Fn14 overexpression enhanced NSCLC cell migration and invasion in vitro and increased experimental lung metastases in vivo. Thus, Fn14 may be a novel therapeutic target for patients with NSCLC, in particular for those with EGFR-driven tumors who have either primary or acquired resistance to EGFR TKIs.

Complexity in the signaling network: insights from the use of targeted inhibitors in cancer therapy

Cancer often arises when normal cellular growth goes awry due to defects in critical signal transduction pathways. A growing number of inhibitors that target specific components of these pathways are in clinical use, but the success of these agents has been limited by the resistance to inhibitor therapy that ultimately develops. Studies have now shown that cancer cells respond to chronic drug treatment by adapting their signaling circuitry, taking advantage of pathway redundancy and routes of feedback and cross-talk to maintain their function. This review focuses on the compensatory signaling mechanisms highlighted by the use of targeted inhibitors in cancer therapy.

NKX2-1/TITF1/TTF-1-Induced ROR1 is required to sustain EGFR survival signaling in lung adenocarcinoma

We and others previously identified NKX2-1, also known as TITF1 and TTF-1, as a lineage-survival oncogene in lung adenocarcinomas. Here we show that NKX2-1 induces the expression of the receptor tyrosine kinase-like orphan receptor 1 (ROR1), which in turn sustains a favorable balance between prosurvival PI3K-AKT and pro-apoptotic p38 signaling, in part through ROR1 kinase-dependent c-Src activation, as well as kinase activity-independent sustainment of the EGFR-ERBB3 association, ERBB3 phosphorylation, and consequential PI3K activation. Notably, ROR1 knockdown effectively inhibited lung adenocarcinoma cell lines, irrespective of their EGFR status, including those with resistance to the EGFR tyrosine kinase inhibitor gefitinib. Our findings thus identify ROR1 as an "Achilles' heel" in lung adenocarcinoma, warranting future development of therapeutic strategies for this devastating cancer.

Intact-cell-based surface plasmon resonance measurements for ligand affinity evaluation of a membrane receptor

Toward future applications to the discovery of drugs against membrane receptors on pathological cells, an intact-cell-based surface plasmon resonance (SPR) methodology has been developed. The injection of a suspension of epidermal carcinoma A431 cells (5×10(7)cells/ml), as an analyte, generated clear SPR responses to epidermal growth factor (EGF) immobilized on the sensor chip. Because the responses were competitively reduced by the free ligand EGF, added to the analyte cell suspension, they certainly reflect the specific interaction of the immobilized EGF with the extracellular region of its receptor, which is highly expressed on the surface of the A431 cells.

Genetic and epigenetic changes in lung carcinoma and their clinical implications

Lung cancer is the leading cause of cancer deaths worldwide. Recent advance in targeted therapy for lung cancer patients with epidermal growth factor receptor (EGFR) mutations has demonstrated a promising development toward personalized therapy for lung cancer patients. The development of lung cancer is a complex process, involving a series of genetic and epigenetic changes. Tobacco smoke is the predominant etiologic risk factor for lung cancer. However, some lung cancers, especially adenocarcinomas, arise in patients who have never smoked, suggesting the importance of host genetic/epigenetic susceptibility in the occurrence and development of lung cancer. Understanding of these genetic and epigenetic changes will further aid in the biomarker-driven personalized therapy for lung cancer patients. In this review, we summarize the genetic and epigenetic alterations observed in lung cancers, including chromosomal loss of heterozygosity, tumor-suppressor gene mutation, gene methylation, histone modification, and microRNA expression changes. Clinical and preclinical studies have implied specific genetic/epigenetic changes for clinical application in lung cancer patients. However, more efforts are required in validation of the identified molecular markers in lung cancer patients for early detections, assessment for treatment response, and survival predictions.

EGFR-mutated lung cancer: a paradigm of molecular oncology

The development of EGFR tyrosine kinase inhibitors for clinical use in non-small cell lung cancer and the subsequent discovery of activating EGFR mutations have led to an explosion of knowledge in the fields of EGFR biology, targeted therapeutics and lung cancer research. EGFR-mutated adenocarcinoma of the lung has clearly emerged as a unique clinical entity necessitating the routine introduction of molecular diagnostics into our current diagnostic algorithms and leading to the evidence-based preferential usage of EGFR-targeted agents for patients with EGFR-mutant lung cancers. This review will summarize our current understanding of the functional role of activating mutations, key downstream signaling pathways and regulatory mechanisms, pivotal primary and acquired resistance mechanisms, structure-function relationships and ultimately the incorporation of molecular diagnostics and small molecule EGFR tyrosine kinase inhibitors into our current treatment paradigms.

EGFR and KRAS mutations in lung carcinoma: molecular testing by using cytology specimens

BACKGROUND

The aim of this study was to validate clinical utilization of routinely prepared cytology specimens for molecular testing to detect EGFR or KRAS mutations in lung cancer.

METHODS

From September 2009 to April 2010, the authors collected 209 cytology specimens from patients with lung cancer at the MD Anderson Cancer Center Department of Pathology. The specimens included 99 cases of endobronchial ultrasound-guided (EBUS) fine-needle aspiration (FNA), 67 cases of computed tomography (CT)-guided FNA, 27 cases of body fluid, 10 cases of ultrasound-guided of superficial FNA, and 6 cases of other cytology specimens. DNA sequencing for EGFR exons 18-21 and KRAS codons 12, 13, and 61 was performed.

RESULTS

The overall specimen insufficiency rate was low (6.2%). EBUS (4%) and body-fluid cases (3.7%) showed lower insufficiency rates than the other cases. Similar insufficiency rates were observed in smears (6.1%) and cell-block sections (6.4%). EGFR mutations were detected in 19.4% (34 of 175) of nonsmall cell lung carcinoma (NSCLC) with a significantly higher frequency in adenocarcinoma (29%, 29 of 100) than in nonadenocarcinoma (7%, 5 of 75, P = .002). KRAS mutations were detected in 23.6% (41 of 174) of NSCLCs with no statistical differences between adenocarcinoma (26%, 26 of 102) and nonadenocarcinoma (21%, 17 of 72, P = .86). Higher frequencies of EGFR mutations in exons 19 and 21 (65%) than in exons 18 and 20 were detected.

CONCLUSIONS

Our findings support clinical utilization of routinely prepared cytology specimens, including EBUS, CT/US. FNAs and body fluid specimens, as a reliable source for molecular testing to detect EGFR or KRAS mutations in patients with NSCLC.

Cytohesins are cytoplasmic ErbB receptor activators

Signaling by ErbB receptors requires the activation of their cytoplasmic kinase domains, which is initiated by ligand binding to the receptor ectodomains. Cytoplasmic factors contributing to the activation are unknown. Here we identify members of the cytohesin protein family as such factors. Cytohesin inhibition decreased ErbB receptor autophosphorylation and signaling, whereas cytohesin overexpression stimulated receptor activation. Monitoring epidermal growth factor receptor (EGFR) conformation by anisotropy microscopy together with cell-free reconstitution of cytohesin-dependent receptor autophosphorylation indicate that cytohesins facilitate conformational rearrangements in the intracellular domains of dimerized receptors. Consistent with cytohesins playing a prominent role in ErbB receptor signaling, we found that cytohesin overexpression correlated with EGF signaling pathway activation in human lung adenocarcinomas. Chemical inhibition of cytohesins resulted in reduced proliferation of EGFR-dependent lung cancer cells in vitro and in vivo. Our results establish cytohesins as cytoplasmic conformational activators of ErbB receptors that are of pathophysiological relevance.

p130Cas promotes invasiveness of three-dimensional ErbB2-transformed mammary acinar structures by enhanced activation of mTOR/p70S6K and Rac1

ErbB2 over-expression is detected in approximately 25% of invasive breast cancers and is strongly associated with poor patient survival. We have previously demonstrated that p130Cas adaptor is a crucial mediator of ErbB2 transformation. Here, we analysed the molecular mechanisms through which p130Cas controls ErbB2-dependent invasion in three-dimensional cultures of mammary epithelial cells. Concomitant p130Cas over-expression and ErbB2 activation enhance PI3K/Akt and Erk1/2 MAPK signalling pathways and promote invasion of mammary acini. By using pharmacological inhibitors, we demonstrate that both signalling cascades are required for the invasive behaviour of p130Cas over-expressing and ErbB2 activated acini. Erk1/2 MAPK and PI3K/Akt signalling triggers invasion through distinct downstream effectors involving mTOR/p70S6K and Rac1 activation, respectively. Moreover, in silico analyses indicate that p130Cas expression in ErbB2 positive human breast cancers significantly correlates with higher risk to develop distant metastasis, thus underlying the value of the p130Cas/ErbB2 synergism in regulating breast cancer invasion. In conclusion, high levels of p130Cas favour progression of ErbB2-transformed cells towards an invasive phenotype.

Epidermal growth factor receptor in triple-negative and basal-like breast cancer: promising clinical target or only a marker?

Triple-negative breast cancers represent a subset of breast cancers with a particularly aggressive phenotype and poor clinical outcomes. Recent molecular profiling of these tumors has revealed a high frequency of epidermal growth factor receptor (EGFR) dysregulation, among other abnormalities. EGFR status correlates negatively with survival in patients with triple-negative breast cancers, and thus focus has turned on this receptor as a potential clinical target. Two classes of EGFR inhibitors are currently in clinical use: the monoclonal antibodies and the small molecule tyrosine kinase inhibitors. Trials of these drugs in breast cancer, however, have been largely disappointing. It remains to be seen whether advances in our understanding of the mechanisms of EGFR dysregulation and effects of multiple compensatory pathways in breast cancer, coupled with improved targeting to appropriate patient populations, will yield meaningful improvements in clinical outcomes.

Expression levels of some antioxidant and epidermal growth factor receptor genes in patients with early-stage non-small cell lung cancer

This study was aimed at: (i) investigating the expression profiles of some antioxidant and epidermal growth factor receptor genes in cancerous and unaffected tissues of patients undergoing lung resection for non-small cell lung cancer (NSCLC) (cross-sectional phase), (ii) evaluating if gene expression levels at the time of surgery may be associated to patients' survival (prospective phase). Antioxidant genes included heme oxygenase 1 (HO-1), superoxide dismutase-1 (SOD-1), and -2 (SOD-2), whereas epidermal growth factor receptor genes consisted of epidermal growth factor receptor (EGFR) and v-erb-b2 erythroblastic leukaemia viral oncogene homolog 2 (HER-2). Twenty-eight couples of lung biopsies were obtained and gene transcripts were quantified by Real Time RT-PCR. The average follow-up of patients lasted about 60 months. In the cancerous tissues, antioxidant genes were significantly hypo-expressed than in unaffected tissues. The HER-2 transcript levels prevailed in adenocarcinomas, whereas EGFR in squamocellular carcinomas. Patients overexpressing HER-2 in the cancerous tissues showed significantly lower 5-year survival than the others.

HER2 targeting as a two-sided strategy for breast cancer diagnosis and treatment: Outlook and recent implications in nanomedical approaches

At present, mammary carcinoma is the second most common type of malignant tumor in adult women after lung cancer, as more than one million women are diagnosed with breast cancer every year. Despite advances in diagnosis and treatment, which have resulted in a decrease in mortality in recent decades, breast cancer remains a major public health problem. One of the most significant unresolved clinical and scientific problems is the occurrence of resistance to clinical treatments and their toxicity (and how to predict, prevent and overcome them). However, the heterogeneity of human breast cancer in terms of genetic features, molecular profiles and clinical behavior represents a constraint obstructing the discovery of a solution to the disease. It is currently considered that the chances of success of therapy may increase if the tumor cells are selectively removed before they can evolve to their mature stages up to metastases production. Therefore, novel and more sensitive diagnostic tools are being developed, with the aim of improving the early and noninvasive detection of rising malignancies and the accuracy of tumor tissue localization. Meanwhile, there is an emerging use of targeted therapies in oncology, depending on the expression of specific proteins or genes present in tumor cells. Among the molecular targets considered for the treatment of breast cancer cells so far, we chose to focus on examples involving overexpression and/or gene amplification of "Human Epidermal growth factor Receptor 2" (HER2) protein. In current studies, various types of nanoparticles conjugated with the anti-HER2 monoclonal antibody, the so-called "trastuzumab", are investigated extensively due to promising results in biological and preclinical applications aimed at improving the treatment of breast cancer. In this paper, we present a critical review of the preparation and use of different kinds of trastuzumab-functionalized nanoparticles, with an emphasis on the therapeutic and diagnostic (theranostic) potential of this generation of hybrid nanoparticles, exploiting the multifaceted mechanisms of action of trastuzumab against malignant cells.

ErbB receptors and signaling pathways in cancer

The ErbB receptor tyrosine kinases play important roles in normal physiology and in cancer. Epidermal growth factor receptor (EGFR) and ErbB2 in particular are mutated in many epithelial tumors, and clinical studies suggest that they play roles in cancer development and progression. These receptors have been intensely studied, not only to understand the mechanisms underlying their oncogenic potential, but also to exploit them as therapeutic targets. ErbB receptors activate a multiplicity of intracellular pathways via their ability to interact with numerous signal transducers. Furthermore, there are now many ErbB-targeted inhibitors used in the clinic. In this review we will concentrate on breast tumors with ERBB2 gene amplification/receptor overexpression and non-small cell lung cancer (NSCLC) with activating EGFR mutations. We will discuss data showing the important role that the PI3K/Akt pathway plays, not only in cancer development, but also in response to targeted therapies. Finally, mechanisms contributing to resistance to ErbB-targeted therapeutics will also be discussed.