Epidermal growth factor receptor inhibition in lung cancer: the evolving role of individualized therapy

Involvement of HDAC2-mediated kcnq2/kcnq3 genes transcription repression activated by EREG/EGFR-ERK-Runx1 signaling in bone cancer pain

Bone cancer pain (BCP) represents a prevalent symptom among cancer patients with bone metastases, yet its underlying mechanisms remain elusive. This study investigated the transcriptional regulation mechanism of Kv7(KCNQ)/M potassium channels in DRG neurons and its involvement in the development of BCP in rats. We show that HDAC2-mediated transcriptional repression of kcnq2/kcnq3 genes, which encode Kv7(KCNQ)/M potassium channels in dorsal root ganglion (DRG), contributes to the sensitization of DRG neurons and the pathogenesis of BCP in rats. Also, HDAC2 requires the formation of a corepressor complex with MeCP2 and Sin3A to execute transcriptional regulation of kcnq2/kcnq3 genes. Moreover, EREG is identified as an upstream signal molecule for HDAC2-mediated kcnq2/kcnq3 genes transcription repression. Activation of EREG/EGFR-ERK-Runx1 signaling, followed by the induction of HDAC2-mediated transcriptional repression of kcnq2/kcnq3 genes in DRG neurons, leads to neuronal hyperexcitability and pain hypersensitivity in tumor-bearing rats. Consequently, the activation of EREG/EGFR-ERK-Runx1 signaling, along with the subsequent transcriptional repression of kcnq2/kcnq3 genes by HDAC2 in DRG neurons, underlies the sensitization of DRG neurons and the pathogenesis of BCP in rats. These findings uncover a potentially targetable mechanism contributing to bone metastasis-associated pain in cancer patients.

Deep Learning-Based H-Score Quantification of Immunohistochemistry-Stained Images

Immunohistochemistry (IHC) is a well-established and commonly used staining method for clinical diagnosis and biomedical research. In most IHC images, the target protein is conjugated with a specific antibody and stained using diaminobenzidine (DAB), resulting in a brown coloration, whereas hematoxylin serves as a blue counterstain for cell nuclei. The protein expression level is quantified through the H-score, calculated from DAB staining intensity within the target cell region. Traditionally, this process requires evaluation by 2 expert pathologists, which is both time consuming and subjective. To enhance the efficiency and accuracy of this process, we have developed an automatic algorithm for quantifying the H-score of IHC images. To characterize protein expression in specific cell regions, a deep learning model for region recognition was trained based on hematoxylin staining only, achieving pixel accuracy for each class ranging from 0.92 to 0.99. Within the desired area, the algorithm categorizes DAB intensity of each pixel as negative, weak, moderate, or strong staining and calculates the final H-score based on the percentage of each intensity category. Overall, this algorithm takes an IHC image as input and directly outputs the H-score within a few seconds, significantly enhancing the speed of IHC image analysis. This automated tool provides H-score quantification with precision and consistency comparable to experienced pathologists but at a significantly reduced cost during IHC diagnostic workups. It holds significant potential to advance biomedical research reliant on IHC staining for protein expression quantification.

Conversion from Positive to Negative EGFR Mutation due to Clonal Selection during Long-Term Treatment with Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors: A Case Report

A 77-year-old woman with postoperative recurrent non-small cell lung adenocarcinoma, which exhibited an epidermal growth factor receptor (EGFR) L858R mutation, was treated with gefitinib and erlotinib. Seven years after the start of treatment, the patient experienced a recurrence of malignant pleural effusion. However, 3 different genetic tests revealed that the lung adenocarcinoma cells in the pleural effusion had lost EGFR L858R mutation, suggesting that long-term treatment with EGFR-tyrosine kinase inhibitors (TKIs) converted EGFR mutation from positive to negative. The negative conversion of EGFR mutation as a mechanism of acquired resistance to EGFR-TKIs is considered rare and needs to be further investigated.

A novel EGFR inhibitor suppresses survivin expression and tumor growth in human gefitinib-resistant EGFR-wild type and -T790M non-small cell lung cancer

Tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) are currently used therapy for non-small cell lung cancer (NSCLC) patients; however, drug resistance during cancer treatment is a critical problem. Survivin is an anti-apoptosis protein, which promotes cell proliferation and tumor growth that highly expressed in various human cancers. Here, we show a novel synthetic compound derived from gefitinib, do-decyl-4-(4-(3-(4-(3-chloro-4-fluorophenylamino)-7-methoxyquinazolin-6-yloxy)propyl) piper-azin-1-yl)-4-oxobutanoate, which is named as SP101 that inhibits survivin expression and tumor growth in both the EGFR-wild type and -T790M of NSCLC. SP101 blocked EGFR kinase activity and induced apoptosis in the A549 (EGFR-wild type) and H1975 (EGFR-T790M) lung cancer cells. SP101 reduced survivin proteins and increased active caspase 3 for inducing apoptosis. Ectopic expression of survivin by a survivin-expressed vector attenuated the SP101-induced cell death in lung cancer cells. Moreover, SP101 inhibited the gefitinib-resistant tumor growth in the xenograft human H1975 lung tumors of nude mice. SP101 substantially reduced survivin proteins but conversely elicited active caspase 3 proteins in tumor tissues. Besides, SP101 exerted anticancer abilities in the gefitinib resistant cancer cells separated from pleural effusion of a clinical lung cancer patient. Consistently, SP101 decreased the survivin proteins and the patient-derived xenografted lung tumor growth in nude mice. Anti-tumor ability of SP101 was also confirmed in the murine lung cancer model harboring EGFR T790M-L858R. Together, SP101 is a new EGFR inhibitor with inhibiting survivin that can be developed for treating EGFR wild-type and EGFR-mutational gefitinib-resistance in human lung cancers.

Nanotechnology Assisted Chemotherapy for Targeted Cancer Treatment: Recent Advances and Clinical Perspectives

Nanotechnology has recently provided exciting platforms in the field of anticancer research with promising potentials for improving drug delivery efficacy and treatment outcomes. Nanoparticles (NPs) possess different advantages over the micro and bulk therapeutic agents, including their capability to carry high payloads of drugs, with prolonged half-life, reduced toxicity of the drugs, and increased targeting efficiency. The wide variety of nanovectors, coupled with different conjugation and encapsulation methods available for different theranostic agents provide promising opportunities to fine-tune the pharmacological properties of these agents for more effective cancer treatment methods. This review discusses applications of NPs-assisted chemotherapy in preclinical and clinical settings and recent advances in design and synthesis of different nanocarriers for chemotherapeutic agents. Moreover, physicochemical properties of different nanocarriers, their impacts on different tumor targeting strategies and effective parameters for efficient targeted drug delivery are discussed. Finally, the current approved NPs-assisted chemotherapeutic agents for clinical applications and under different phases of clinical trials are discussed.

Evaluation of molecular subtypes and clonal selection during establishment of patient-derived tumor xenografts from gastric adenocarcinoma

Patient-derived xenografts (PDX) have emerged as an important translational research tool for understanding tumor biology and enabling drug efficacy testing. They are established by transfer of patient tumor into immune compromised mice with the intent of using them as Avatars; operating under the assumption that they closely resemble patient tumors. In this study, we established 27 PDX from 100 resected gastric cancers and studied their fidelity in histological and molecular subtypes. We show that the established PDX preserved histology and molecular subtypes of parental tumors. However, in depth investigation of the entire cohort revealed that not all histological and molecular subtypes are established. Also, for the established PDX models, genetic changes are selected at early passages and rare subclones can emerge in PDX. This study highlights the importance of considering the molecular and evolutionary characteristics of PDX for a proper use of such models, particularly for Avatar trials.

Expression of female sex hormone receptors and its relation to clinicopathological characteristics and prognosis of lung adenocarcinoma

BACKGROUND

Adenocarcinoma (ADC) of the lung exhibits different clinicopathological characteristics in men and women. Recent studies have suggested that these differences originate from the expression of female sex hormone receptors in tumor cells. The aim of the present study was to evaluate the immunohistochemical expression of female sex hormone receptors in lung ADC and determine the expression patterns in patients with different clinicopathological characteristics.

METHODS

A total of 84 patients with lung ADC who underwent surgical resection and/or core biopsy were recruited for the present study. Immunohistochemical staining was performed for estrogen receptor α (ERα), estrogen receptor β (ERβ), progesterone receptor (PR), epidermal growth factor receptor (EGFR), EGFR E746- A750 del, and EGFR L858R using tissue microarray.

RESULTS

A total of 39 (46.4%) ERα-positive, 71 (84.5%) ERβ-positive, and 46 (54.8%) PR-positive lung ADCs were identified. In addition, there were 81 (96.4%) EGFR-positive, 14 (16.7%) EGFR E746-A750 del-positive, and 34 (40.5%) EGFR L858R-positive cases. The expression of female sex hormone receptors was not significantly different in clinicopathologically different subsets of lung ADC.

CONCLUSIONS

Expression of female sex hormone receptors is not associated with the prognosis and clinicopathological characteristics of patients with lung ADC.

[Second- or third-line treatment with erlotinib in EGFR wild-type non-small cell lung cancer: Real-life data]

INTRODUCTION

The benefit of tyrosine kinase inhibitors for patients with an EGFR wild-type non-small cell lung cancer (NSCLC) remains controversial.

METHODS

The survival of patients with an EGFR wild-type NSCLC who received second- or third-line erlotinib treatment was assessed using real-life data that had been collected in a prospective, national, multicenter, non-interventional cohort study.

RESULTS

Data from 274 patients were analysed, 185 (68%) treated with erlotinib and 89 (32%) treated with supportive care only. The median overall survival was 4.2months (95% CI [3.5; 5.4]) with erlotinib, and 1.3months (95% CI [1.0; 1.8]) with supportive care. Survival rate at 3, 6, and 12months was 62%, 37%, and 17%, respectively, with erlotinib, versus 20%, 8%, et 3%, with exclusive supportive care. Significant predictive factors for longer overall survival were the presence of adenocarcinoma, and use of 1st line chemotherapy including either taxanes, pemetrexed or vinorelbine (P<0.05).

CONCLUSION

Erlotinib remains a valuable therapeutic option to treat inoperable locally advanced or metastatic NSCLC after failure of at least one prior chemotherapy regimen in fragile patients who are not eligible for chemotherapy.

Pathways regulating the expression of the immunomodulatory protein glycodelin in non‑small cell lung cancer

Glycodelin [gene name, progesterone associated endometrial protein (PAEP)] was initially described as an immune system modulator in reproduction. Today, it is also known to be expressed in several types of cancer, including non‑small cell lung cancer (NSCLC). In this cancer type, the feasibility of its usage as a follow‑up biomarker and its potential role as an immune system modulator were described. It is assumed that NSCLC tumours secrete glycodelin to overcome immune surveillance. Therefore, targeting glycodelin might be a future approach with which to weaken the immune system defence of NSCLC tumours. In this context, it is important to understand the regulatory pathways of PAEP/glycodelin expression, as these are mostly unknown so far. In this study, we analysed the influence of several inducers and of their downstream pathways on PAEP/glycodelin expression in a human lung adenocarcinoma carcinoma (ADC; H1975) and a human lung squamous cell carcinoma (SQCC) cell line (2106T). PAEP/glycodelin expression was notably stimulated by the canonical transforming growth factor (TGF)‑β pathway in SQCC cells and the PKC signalling cascade in both cell lines. The PI3K/AKT pathway inhibited PAEP/glycodelin expression in the ADC cells and an antagonizing role towards the other investigated signalling cascades is suggested herein. Furthermore, the mitogen‑activated protein kinase kinase (MEK)/extracellular‑signal regulated kinases (ERK) pathway was, to a lesser extent, found to be associated with increased PAEP/glycodelin amounts. The phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT), MEK/ERK pathway and TGF‑β are targets of NSCLC drugs that are already approved or are currently under investigation. On the whole, the findings of this study provide evidence that inhibiting these targets affects the expression of glycodelin and its immunosuppressive effect in NSCLC tumours. Moreover, understanding the regulation of glycodelin expression may lead to the development of novel therapeutic approaches with which to weaken the immune system defence of NSCLC tumours in the future.

LncRNA DUXAP9-206 directly binds with Cbl-b to augment EGFR signaling and promotes non-small cell lung cancer progression

Long noncoding RNAs (lncRNAs) are involved in the pathology of various tumours, including non‐small cell lung cancer (NSCLC). However, the underlying molecular mechanisms of their specific association with NSCLC have not been fully elucidated. Here, we report that a cytoplasmic lncRNA, DUXAP9‐206 is overexpressed in NSCLC cells and closely related to NSCLC clinical features and poor patient survival. We reveal that DUXAP9‐206 induced NSCLC cell proliferation and metastasis by directly interacting with Cbl‐b, an E3 ubiquitin ligase, and reducing the degradation of epidermal growth factor receptor (EGFR) and thereby augmenting EGFR signaling in NSCLC. Notably, correlations between DUXAP9‐206 and activated EGFR signaling were also validated in NSCLC patient specimens. Collectively, our findings reveal the novel molecular mechanisms of DUXAP9‐206 in mediating the progression of NSCLC and DUXAP9‐206 may serve as a potential target for NSCLC therapy.

Significant Improvement in Detecting BRAF, KRAS, and EGFR Mutations Using Next-Generation Sequencing as Compared with FDA-Cleared Kits

Introduction

We compared mutations detected in EGFR, KRAS, and BRAF genes using next-generation sequencing (NGS) and confirmed by Sanger sequencing with mutations that could be detected by FDA-cleared testing kits.

Methods

Paraffin-embedded tissue from 822 patients was tested for mutations in EGFR, KRAS, and BRAF by NGS. Sanger sequencing of hot spots was used with locked nucleic acid to increase sensitivity for specific hot-spot mutations. This included 442 (54%) lung cancers, 168 (20%) colorectal cancers, 29 (4%) brain tumors, 33 (4%) melanomas, 14 (2%) thyroid cancers, and 16% others (pancreas, head and neck, and cancer of unknown origin). Results were compared with the approved list of detectable mutations in FDA kits for EGFR, KRAS, and BRAF.

Results

Of the 101 patients with EGFR abnormalities as detected by NGS, only 58 (57%) were detectable by cobas v2 and only 35 (35%) by therascreen. Therefore, 42 and 65%, respectively, more mutations were detected by NGS, including two patients with EGFR amplification. Of the 117 patients with BRAF mutation detected by NGS, 62 (53%) mutations were within codon 600, detectable by commercial kits, but 55 (47%) of the mutations were outside codon V600, detected by NGS only. Of the 321 patients with mutations in KRAS detected by NGS, 284 (88.5%) had mutations detectable by therascreen and 300 (93.5%) had mutations detectable by cobas. Therefore, 11.5 and 6.5% additional KRAS mutations were detected by NGS, respectively.

Conclusion

NGS provides significantly more comprehensive testing for mutations as compared with FDA-cleared kits currently available commercially.

COPB2 promotes cell proliferation and tumorigenesis through up-regulating YAP1 expression in lung adenocarcinoma cells

Lung adenocarcinoma is the most common subtype of non-small cell lung cancer and responsible for more than 500,000 deaths per year worldwide. In this study, we aimed to explore the effects of COPB2 in the progression of lung adenocarcinoma and its underlying mechanism. The mRNA and protein levels of COPB2 in tumor tissues and cell lines were determined by qRT-PCR and western blotting analysis. siRNAs and over-expressed vector targeting COPB2 were used to down-regulate and up-regulate COPB2 expression in lung adenocarcinoma cell lines H1975. Cell apoptosis rate, proliferation and tumorigenesis of H1975 cells were determined by flow cytometry analysis, MTT assay and in vivo xenotransplantation assay, respectively. Western blotting and immunofluorescence assays were performed to evaluate the effects of COPB on the expression and subcellular location of YAP. Results showed COPB2 was significantly up-regulated in lung adenocarcinoma tissues and cell lines, which showed a close correlation with advanced clinical symptoms, such as tumor differentiation, TNM stage and the occurrence of lymph node metastasis and distance metastasis. Besides, the overall survival time of patients with high expression of COPB2 was shorter than that of patients with low COPB2 expression. After knockdown of COPB2, cell apoptosis rate was increased, whereas cell proliferation was decreased. Compared with that in the normal lung cell line H1688 cells, YAP1 expression was obviously increased in H1975, and over-expression of COPB2 translocated YAP1 from cytoplasm to nuclear, whereas knockdown of COPB2 showed the opposite effect. Overexpression of COPB2 enhanced cell proliferation, tumorigenesis and inhibited cell apoptosis. However, these effects were abolished when down-regulated YAP1 expression on the base of COPB2 over-expression. In conclusion, the increased expression of COPB2 was significantly correlated with the progression of lung adenocarcinoma. Up-regulation of COPB2 inhibited cell apoptosis and promoted cell growth and tumorigenesis through up-regulating YAP1 expression in lung adenocarcinoma.

Mistletoe (Viscum album) extract targets Axl to suppress cell proliferation and overcome cisplatin- and erlotinib-resistance in non-small cell lung cancer cells

BACKGROUND

Mistletoe extract of Visucm album extract (VAE) contains many biologically active components and has been reported to be not only a complementary and alternative medicine, but also a potent therapeutic agent for many types of cancer.

PURPOSE

In this study, we examined the effect of VAE on expression and activation of Axl and scrutinized the involvement of Axl in the anti-cancer activity of VAE in parental and chemo-resistant non-small cell lung cancer (NSCLC) cells.

METHODS

The levels of Axl protein and mRNA were determined by Western blot analysis and RT-PCR, respectively. Phosphorylation of Axl upon Gas6 stimulation was observed by Western blot analysis. For ectopic expression or gene silencing of Axl, the recombinant plasmid, pcDNA3-Axl, or specific siRNA targeting Axl were transfected into A549 and H460 cells using Lipofectamine 2000, respectively. The anti-cancer activity of mistletoe extract was examined against the parental cells and each of their cisplatin- or erlotinib-resistant cells using trypan blue exclusion assays and colony formation assay.

RESULTS

The levels of Axl mRNA were also reduced by VAE treatment, implying the transcriptional downregulation of Axl expression by VAE. In addition, the phosphorylation of Axl protein upon its ligand, Gas6, stimulation was found to be abrogated by VAE. We next found cytotoxic effect of VAE on both the parental NSCLC cells and their variants which are resistant to cisplatin (A549/CisR and H460/CisR) or erlotinib (H460/ER and H1975/ER). Treatment of these cells with VAE caused a dose-dependent decrease of cell viability and clonogenicity. This anti-proliferative effect of VAE was attenuated in Axl-overexpressing cells, while it was augmented in cells transfected Axl specific siRNA. Next, we also found that in cisplatin-resistant cells and erlotinib-resistant cells, VAE treatment decreased Axl protein level, colonogenicity. The levels of several cell cycle regulator, p21 and apoptosis related protein, X-linked inhibitor of apoptosis, was found to be induced and reduced by VAE treatment, respectively.

CONCLUSION

Taken together, our data provide that VAE targets Axl to suppress cell proliferation and to circumvent cisplatin- and erlotinib-resistance in NSCLC cells.

Advances in targeting the transforming growth factor β1 signaling pathway in lung cancer radiotherapy

Lung cancer was demonstrated to be the most lethal type of malignant tumor amongst humans in the global cancer statistics of 2012. As one of the primary treatments, radiotherapy has been reported to induce remission in, and even cure, patients with lung cancer. However, the side effects of radiotherapy may prove lethal in certain patients. In past decades, the transforming growth factor β1 (TGFB1) signaling pathway has been revealed to serve multiple functions in the control of lung cancer progression and the radiotherapy response. In mammals, this signaling pathway is initiated through activation of the TGFB1 receptor complex, which signals via cytoplasmic SMAD proteins or other downstream signaling pathways. Multiple studies have demonstrated that TGFB1 serves important functions in lung cancer radiotherapy. The present study summarized and reviewed recent progress in elucidating the function of the TGFB1 signaling pathway in predicting radiation pneumonitis, as well as current strategies for targeting the TGFB1 signaling pathway in lung cancer radiotherapy, which may provide potential targets for lung cancer therapy.

Polymorphisms in genes related to epithelial-mesenchymal transition and risk of non-small cell lung cancer

The epithelial-mesenchymal transition (EMT) process is a crucial step for tumor invasion and metastasis. Previous research investigating EMT has mostly focused on its role in cancer progression. Recent studies showed that EMT and EMT-driving transcription factor (EMT-TF) expression are early events in lung cancer pathogenesis, implying a potential association between EMT and lung cancer risk. In this study, we examined whether genetic variants in EMT-related genes are associated with risk of non-small cell lung cancer (NSCLC). We used data from a genome-wide association study of 1482 NSCLC cases and 1544 healthy controls as the discovery phase, in which we analyzed 1602 single-nucleotide polymorphisms (SNPs) within 159 EMT-related genes. We then validated the significant SNPs in another 5699 cases and 5815 controls from the National Cancer Institute lung cancer genome-wide association study. Cumulative effects were evaluated for validated SNPs, and a gene-based test was performed to explore gene-level association with disease risk. In the discovery phase, 174 SNPs demonstrated significant associations with NSCLC risk. In the validation phase, seven SNPs mapped to EGFR, NOTCH3, ADGRF1 and SMAD3 were confirmed. Cumulative effect analysis of the significant SNPs demonstrated increasing risk with the number of unfavorable genotypes in the discovery and validation datasets. Gene-based analysis implicated ADGRF1, NOTCH3 and CDH1 as significant for NSCLC risk. Functional prediction revealed several potential mechanisms underlying these associations. Our results suggest that EMT-related gene variants may be involved in susceptibility to NSCLC; if confirmed, they might help identify higher-risk individuals.

Intrapleural targeted therapies (anti-VEGF and anti-EGFR) in the model of malignant pleural effusion

Rationale

Malignant pleural effusion has few options of treatment and drugs administrated by different routes can lead to a less permissive microenvironment for the development of malignant pleural disease.

Objectives

To analyze therapies administered intrapleurally in malignant pleural disease and to study EGFR and KRAS mutations in adenocarcinoma.

Methods

Mice received LLC cells and were treated intrapleurally with anti-VEGF, anti-EGFR, anti-VEGF+anti-EGFR or saline. Animal survival, weight and mobility, volume, biochemistry and immunology of fluid, gene expression, KRAS and EGFR mutation were evaluated.

Results

All animals developed malignant effusion and presented progressive weight loss without difference between groups; however, groups treated with anti-EGFR were more active. No difference in mortality was observed. Temporal increase of volume and inflammatory markers was observed mainly in the untreated group. Gene expression in tumors was overexpressed in VEGF, EGFR and KRAS compared with normal tissue. Mutation in exon 2 of the KRAS gene was observed.

Conclusions

Intrapleural Anti-VEGF and/or anti-EGFR reduced volume and inflammatory mediators in pleural fluid. Anti-EGFR and anti-VEGF+anti-EGFR decreased morbidity although without impact on survival. LLC tumors presented KRAS mutation, this could have influenced the action of these therapies.

Randomized Phase II Study of Afatinib Plus Simvastatin Versus Afatinib Alone in Previously Treated Patients with Advanced Nonadenocarcinomatous Non-small Cell Lung Cancer

PURPOSE

This phase II study examined whether the addition of simvastatin to afatinib provides a clinical benefit compared with afatinib monotherapy in previously treated patients with nonadenocarcinomatous non-small cell lung cancer (NA-NSCLC).

MATERIALS AND METHODS

Patients with advanced NA-NSCLC who progressed after one or two chemotherapy regimens were randomly assigned to a simvastatin (40 mg/day) plus afatinib (40 mg/day) (AS) arm or to an afatinib (A) arm. The primary endpoint was response rate (RR).

RESULTS

Sixty-eight patients were enrolled (36 in the AS arm and 32 in the A arm). The RR was 5.7% (95% confidence interval [CI], 0.7 to 19.2) for AS and 9.4% (95% CI, 2.0 to 25.0) for A (p=0.440). In arms AS and A, the median progression-free survival (PFS) was 1.0 versus 3.6 months (p=0.240) and the overall survival was 10.0 months versus 7.0 months (p=0.930), respectively. Skin rash, stomatitis, and diarrhea were the most common adverse events in both arms. More grade 3 or 4 diarrhea was observed in arm A (18.8% vs. 5.6% in arm AS). In all patients, the median PFS for treatment including afatinib was not correlated with the status of epidermal growth factor receptor (EGFR) mutation (p=0.122), EGFR fluorescence in situ hybridization (p=0.944), or EGFR immunohistochemistry (p=0.976). However, skin rash severity was significantly related to the risk of progression for afatinib (hazard ratio for skin rash grade ≥ 2 vs. grade < 2, 0.44; 95% CI, 0.25 to 0.78; p=0.005).

CONCLUSION

There were no significant differences in the efficacy between AS and A arms in patients with NA-NSCLC.

Reproducibility of the EGFR immunohistochemistry scores for tumor samples from patients with advanced non-small cell lung cancer

Epidermal growth factor receptor (EGFR) is overexpressed in >60% of non-small cell lung cancer (NSCLC) cases. In combination with radiotherapy or chemotherapy, first-line treatments with antibodies against EGFR, including cetuximab and necitumumab, have demonstrated benefits by increasing overall survival (OS), particularly in patients who overexpress EGFR. The present study evaluated the interobserver agreement among three senior pathologists, who were blinded to the clinical outcomes and assessed tumor samples from 85 patients with NSCLC using the H-score method. EGFR immunohistochemistry was performed using a qualitative immunohistochemical kit. The reported (mean ± standard deviation) H-scores from each pathologist were 111±102, 127±103 and 128.53±104.03. The patients with average H-scores ≥1, ≥100, ≥200 and between 250-300 were 85.9, 54.1, 28.2 and 12.9, respectively. Patients who had an average H-score >100 had a shorter OS time compared with those with lower scores. Furthermore, patients with EGFR mutations who were treated with EGFR-tyrosine kinase inhibitors (TKIs) and had an average H-score >100 had a longer OS time compared with those with an average H-score <100. The interobserver concordance for the total H-scores were 0.982, 0.980 and 0.988, and for a positive H-score ≥200, the interobserver concordance was 0.773, 0.710 and 0.675, respectively. The determination of EGFR expression by the H-score method is highly reproducible among pathologists and is a prognostic factor associated with a poor OS in all patients. Additionally, the results of the present study suggest that patients with EGFR mutations that are treated with EGFR-TKIs and present with a high H-score have a longer OS time.

HBx sensitizes hepatocellular carcinoma cells to lapatinib by up-regulating ErbB3

Poor prognosis of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HCC) involves HBV X protein (HBx)-induced tumor progression. HBx also contributes to chemo-resistance via inducing the expressions of anti-apoptosis and multiple drug resistance genes. However, the impact of HBx expression on the therapeutic efficacy of various receptor tyrosine kinase inhibitors remains unknown. In this study, our data showed that HBx overexpression did not alter the cellular sensitivity of HCC cell lines to sorafenib but unexpectedly enhanced the cell death induced by EGFR family inhibitors, including gefitinib, erlotinib, and lapatinib due to ErbB3 up-regulation. Mechanistically, HBx transcriptionally up-regulates ErbB3 expression in a NF-κB dependent manner. In addition, HBx also physically interacts with ErbB2 and ErbB3 proteins and enhances the formation of ErbB2/ErbB3 heterodimeric complex. The cell viability of HBx-overexpressing cells was decreased by silencing ErbB3 expression, further revealing the pivotal role of ErbB3 in HBx-mediated cell survival. Our data suggest that HBx shifts the oncogenic addiction of HCC cells to ErbB2/ErbB3 signaling pathway via inducing ErbB3 expression and thereby enhances their sensitivity to EGFR/ErbB2 inhibitors.

Spotlight on afatinib and its potential in the treatment of squamous cell lung cancer: the evidence so far

Compared to adenocarcinoma, fewer effective treatment options are available for advanced or metastatic squamous cell carcinoma (SCC) of the lung. Afatinib is an orally administered, irreversible EGFR antagonist. As a second-generation tyrosine kinase inhibitor, it has been applied in the treatment of patients with EGFR-mutant non-small-cell lung cancer. Recently, several clinical trials have shown that afatinib leads to a significant improvement in progression-free survival and overall survival of patients with SCC. Moving forward, afatinib should be one of the options among tyrosine kinase inhibitors, monoclonal antibodies, and cytotoxicity chemotherapy drugs for SCC.

MLK3 Signaling in Cancer Invasion

Mixed-lineage kinase 3 (MLK3) was first cloned in 1994; however, only in the past decade has MLK3 become recognized as a player in oncogenic signaling. MLK3 is a mitogen-activated protein kinase kinase kinase (MAP3K) that mediates signals from several cell surface receptors including receptor tyrosine kinases (RTKs), chemokine receptors, and cytokine receptors. Once activated, MLK3 transduces signals to multiple downstream pathways, primarily to c-Jun terminal kinase (JNK) MAPK, as well as to extracellular-signal-regulated kinase (ERK) MAPK, P38 MAPK, and NF-κB, resulting in both transcriptional and post-translational regulation of multiple effector proteins. In several types of cancer, MLK3 signaling is implicated in promoting cell proliferation, as well as driving cell migration, invasion and metastasis.

Epidermal growth factor receptor tyrosine kinase inhibitors in previously treated advanced non-small-cell lung cancer with wild-type EGFR

INTRODUCTION

While epidermal growth factor receptor (EGFR) - tyrosine kinase inhibitors (TKIs) lead to longer progression-free survival (PFS) when compared with conventional chemotherapy in non-small-cell lung cancer (NSCLC) harboring activating EGFR mutations, the role of EGFR-TKI remains unclear in EGFR-wild-type (WT) NSCLC.

AREAS COVERED

This article reviews selected data from randomized trials regarding the use of TKIs in EGFR-WT NSCLC. Nine randomized phase III trials have compared EGFR-TKI with chemotherapy in NSCLC patients in a second or later line setting. Two of these trials, TAILOR and DELTA, which were designed to investigate treatment benefits according to EGFR genotype, demonstrated that docetaxel chemotherapy displayed significantly better in progression-free survival (PFS) when compared with the EGFR-TKI erlotinib. Biomarkers to predict clinical benefits of the drug against EGFR WT tumor, and the efficacy of combination regimens using erlotinib or single-use afatinib against tumors are also covered in this article.

EXPERT OPINION

Considering the modest benefits of erlotinib for EGFR-WT tumors, future studies are warranted, including the exploration of useful biomarkers and new treatment strategies for EGFT-TKI use, as well as the development of more sensitive EGFR mutation tests.

Development of gelatin nanoparticles conjugated with phytohemagglutinin erythroagglutinating loaded with gemcitabine for inducing apoptosis in non-small cell lung cancer cells

Fluorescent gelatin nanoparticles (GNPs) conjugated with PHA-E and carried gemcitabine were synthesized by nanoprecipitation for targeting and treatment of NSCLC cells.

EGFR/HER2 inhibitors effectively reduce the malignant potential of MDR breast cancer evoked by P-gp substrates in vitro and in vivo

Multidrug resistance (MDR) induced by chemotherapy in breast cancer frequently leads to tumor invasion, metastasis and poor clinical outcome. We preliminarily found that the epidermal growth factor receptor (EGFR) is involved in enhancing the malignant potential of MDR breast cancer cells, but the mechanism remains unclear. In the present study, we demonstrated in vitro and in vivo that EGFR/HER2 promote the invasive and metastatic abilities of MDR breast cancer. More importantly, a new function of EGFR/HER2 inhibitors was revealed for the first time, which could improve the treatment efficacy of breast cancer by reversing the MDR process rather than by inhibiting tumor growth. Firstly, using quantitative real‑time PCR and western blot analysis, we found that overexpression of EGFR/HER2 in MCF7/Adr cells upregulated CD147 and MMP2/9 at both the transcription and protein expression levels, which promoted tumor cell migration, as determined using an in vitro invasion assay. Secondly, the upregulated levels of CD147 and MMP2/9 were decreased when EGFR/HER2 activity was inhibited, and therefore tumor invasion was also significantly inhibited. These phenomena were also demonstrated in nude mouse assays. Additionally, in MDR breast cancer patients, we found that overexpression of EGFR and P‑gp levels led to shorter overall survival (OS) and disease‑free survival (DFS) by IHC assays and Kaplan‑Meier survival analysis. In conclusion, EGFR/HER2 play a crucial role in enhancing CD147 and MMP expression to establish favorable conditions for invasion/metastasis in MDR breast cancer. The scope of application of EGFR/HER2 inhibitors may be expanded in EGFR/HER2‑positive patients. We suggest that MDR breast cancer patients may benefit from novel therapies targeting EGFR/HER2.

Tyr1068-phosphorylated epidermal growth factor receptor (EGFR) predicts cancer stem cell targeting by erlotinib in preclinical models of wild-type EGFR lung cancer

Tyrosine kinase inhibitors (TKIs) have shown strong activity against non-small-cell lung cancer (NSCLC) patients harboring activating epidermal growth factor receptor (EGFR) mutations. However, a fraction of EGFR wild-type (WT) patients may have an improvement in terms of response rate and progression-free survival when treated with erlotinib, suggesting that factors other than EGFR mutation may lead to TKI sensitivity. However, at present, no sufficiently robust clinical or biological parameters have been defined to identify WT-EGFR patients with greater chances of response. Therapeutics validation has necessarily to focus on lung cancer stem cells (LCSCs) as they are more difficult to eradicate and represent the tumor-maintaining cell population. Here, we investigated erlotinib response of lung CSCs with WT-EGFR and identified EGFR phosphorylation at tyrosine1068 (EGFRtyr1068) as a powerful biomarker associated with erlotinib sensitivity both in vitro and in preclinical CSC-generated xenografts. In contrast to the preferential cytotoxicity of chemotherapy against the more differentiated cells, in EGFRtyr1068 cells, erlotinib was even more active against the LCSCs compared with their differentiated counterpart, acquiring potential value as CSC-directed therapeutics in the context of WT-EGFR lung cancer. Although tumor growth was inhibited to a similar extent during erlotinib or chemotherapy administration to responsive tumors, erlotinib proved superior to chemotherapy in terms of higher tolerability and reduced tumor aggressiveness after treatment suspension, substantiating the possibility of preferential LCSC targeting, both in adenocarcinoma (ADC) and squamous cell carcinoma (SCC) tumors. We conclude that EGFRtyr1068 may represent a potential candidate biomarker predicting erlotinib response at CSC-level in EGFR-WT lung cancer patients. Finally, besides its invariable association with erlotinib sensitivity in EGFR-WT lung CSCs, EGFRtyr1068 was associated with EGFR-sensitizing mutations in cell lines and patient tumors, with relevant diagnostic, clinical and therapeutic implications.

Cortactin promotes colon cancer progression by regulating ERK pathway

Cortactin is upregulated in various cancers including breast cancer, head and neck squamous cell carcinoma and gastric cancer. However, the role of cortactin in the pathogenesis of colon cancer remains unclear. mRNA expression of cortactin in colon cancer samples and cell lines was detected by quantitative real-time PCR (qRT-PCR), while protein expression of cortactin in colon cancer tissues and adjacent non-cancer tissues was assessed by immunohistochemistry. The role of cortactin in regulation of the proliferation of colon cancer derived cells were investigated both in vitro and in vivo. In the total of 60 paired colon cancer specimens, compared with the adjacent non-cancer tissues, the expression of cortactin mRNA was upregulated in 45 (75.0%). Immunohistochemical analysis showed significantly increased cortactin expression in colon cancer (42/60, 70.0%) compared to control tissues (18/60, 30.0%). Overexpression of cortactin promoted HCT116 cellular colony formation and tumor growth. Conversely, cortactin knockdown inhibited these effects in SW480 cells. Mechanistic analyses indicated that cortactin was able to activate the EGFR-ERK signaling pathway. Additionally, cortactin expression was associated with tumor size, tumor stages and lymphatic invasion, increased cortactin expression predicts poor prognosis in patients with colon cancer. In summary, cortactin demonstrated the promotive effect in human colon cancer cell growth and tumorigenicity. These results indicated that cortactin may serve as an effective target for gene therapy.

Afatinib: A first-line treatment for selected patients with metastatic non-small-cell lung cancer

PURPOSE

The pharmacology, pharmacokinetics, clinical efficacy, safety, adverse effects, dosage and administration, and role in therapy of afatinib in the management of non-small-cell lung cancer (NSCLC) are reviewed.

SUMMARY

Afatinib (Gilotrif, Boehringer Ingelheim) is a novel oral tyrosine kinase inhibitor (TKI) recently approved for the first-line treatment of patients with NSCLC whose tumors are driven by activating mutations of genes coding for epidermal growth factor receptor (EGFR). Afatinib is also an inhibitor of a specific EGFR mutation (T790M) that causes resistance to first-generation EGFR-targeted TKIs in about half of patients receiving those drugs. The recommended dosage is 40 mg once daily. In a Phase III trial completed last year, patients with EGFR-mutated NSCLC who were treated with afatinib had a twofold higher response rate than those receiving standard combination chemotherapy (56% versus 23%) and significantly longer progression-free survival (11.0 months versus 5.6 months). Other studies indicated that afatinib may offer advantages over standard chemotherapy for NSCLC in terms of enhanced symptom control and quality of life and is modestly effective in cases involving EGFRT790M-related acquired resistance to the TKIs erlotinib and gefitinib. Among clinical trial participants, afatinib was generally well tolerated, with the most common grade I or II adverse events being diarrhea and rash or acne; grade III or IV events were infrequent.

CONCLUSION

Afatinib is a novel TKI that is efficacious and well tolerated in patients with NSCLC associated with activating EGFR mutations, including cases involving the T790M resistance mutation. It has possible applications in other EGFR mutation- positive cancers.

A novel approach to detect KRAS/BRAF mutation for colon cancer: Highly sensitive simultaneous detection of mutations and simple pre-treatment without DNA extraction

It has been reported that colon cancer patients with KRAS and BRAF mutations that lie downstream of epidermal growth factor receptor (EGFR) acquire resistance against therapy with anti-EGFR antibodies, cetuximab and panitumumab. On the other hand, some reports say KRAS codon 13 mutation (p.G13D) has lower resistance against anti-EGFR antibodies, thus there is a substantial need for detection of specific KRAS mutations. We have established a state-of-theart measurement system using QProbe (QP) method that allows simultaneous measurement of KRAS codon 12/13, p.G13D and BRAF mutation, and compared this method against Direct Sequencing (DS) using 182 specimens from colon cancer patients. In addition, 32 biopsy specimens were processed with a novel pre-treatment method without DNA purification in order to detect KRAS/BRAF. As a result of KRAS mutation measurement, concordance rate between the QP method and DS method was 81.4% (144/177) except for the 5 specimens that were undeterminable. Among them, 29 specimens became positive with QP method and negative with DS method. BRAF was measured with QP method only, and the mutation detection rate was 3.9% (6/153). KRAS measurement using a simple new pre-treatment method without DNA extraction resulted in 31 good results out of 32, all of them matching with the DS method. We have established a simple but highly sensitive simultaneous detection system for KRAS/BRAF. Moreover, introduction of the novel pre-treatment technology eliminated the inconvenient DNA extraction process. From this research achievement, we not only anticipate quick and accurate results returned in the clinical field but also contribution in improving the test quality and work efficiency.

Downregulation of ubiquitin inhibits the proliferation and radioresistance of non-small cell lung cancer cells in vitro and in vivo

Radioresistance has been an important factor in restricting efficacy of radiotherapy for non-small cell lung cancer (NSCLC) patients and new approaches to inhibit cancer growth and sensitize irradiation were warranted. Despite the important role of ubiquitin/proteasome system (UPS) during cancer progression and treatment, the expression and biological role of ubiquitin (Ub) in human NSCLC has not been characterized. In this study, we found that ubiquitin was significantly overexpressed in 75 NSCLC tissues, compared to their respective benign tissues by immunohistochemistry (P < 0.0001). Knock-down of ubiquitin by mixed shRNAs targeting its coding genes ubiquitin B (UBB) and ubiquitin C (UBC) suppressed the growth and increased the radiosensitivity in NSCLC H1299 cells. Apoptosis and γ H2AX foci induced by X-ray irradiation were enhanced by knock-down of ubiquitin. Western blot and immunostaining showed that knock-down of ubiquitin decreased the expression and translocation of NF-κB to the nucleus by reduced phospho-IκBα after irradiation. Suppression of ubiquitin decreased the proliferation and radioresistance of H1299 transplanted xenografts in nude mice by promoting apoptosis. Taken together, our results demonstrate the critical role of ubiquitin in NSCLC proliferation and radiosensitivity. Targeting ubiquitin may serve as a potentially important and novel approach for NSCLC prevention and therapy.

Anti-epidermal-growth-factor-receptor agents and complete responses in the treatment of advanced non-small-cell lung cancer: a meta-analysis of 17 phase III randomized controlled trials

PURPOSE

Currently, the anti-epidermal-growth-factor-receptor (EGFR) agents have shown encouraging treatment benefits in patients with various types of solid tumors including non-small-cell lung cancer (NSCLC). Despite these advances, radiological complete response to these therapies is rare. We meta-analyze the incidence of complete response (CR) in advanced NSCLC patients treated with anti-EGFR agents and controls in randomized controlled trials (RCTs).

METHODS

PubMed, Web of Science, Embase and Cochrane library databases were reviewed for phase III RCTs with EGFR-targeted agents vs. non-EGFR-targeted agents in patients with advanced NSCLC. We calculated the odds ratio of CR in patients assigned to anti-EGFR agents compared to controls.

RESULTS

A total of 11,568 patients from 17 RCTs were included for analysis. The incidence of CR in patients treated with anti-EGFR agents was 1.1% (95% CI, 0.7-1.7%) compared to 0.6% (95% CI, 0.4-0.9%) in control arms. Comparing the different types of anti-EGFR agents, the incidence of CR was 1.9% for gefitinib (95% CI: 1.4-2.6%), 1.4% for cetuximab (95% CI: 0.8-2.7%) and 0.9% for erlotinib (95% CI: 0.6-1.5%), respectively. The use of anti-EGFR agents significantly increased the odds ratio of obtaining a CR (OR 2.12, 95% CI: 1.28-3.49, p = 0.003) compared to controls. This was found to be higher in treatment arms involving more than 50% of: female patients, patients who had never smoked tobacco, patients of Asian descent or patients with adenocarcinoma or EGFR mutation. No significant differences in ORs were observed in any prespecified sub-groups.

CONCLUSION

Although a CR is rare in advanced NSCLC patients receiving anti-EGFR agents, these drugs significantly increase the OR of a CR compared to controls, especially for patients with EGFR mutations. Further studies are needed to investigate whether the increase of CR with anti-EGFR therapy would be translated into survival benefits.

Secretory phospholipase A2-IIa upregulates HER/HER2-elicited signaling in lung cancer cells

Lung cancer is the leading cause of cancer death worldwide. There is an urgent need for early diagnostic tools and novel therapies in order to increase lung cancer survival. Secretory phospholipase A2 group IIa (sPLA2-IIa) is involved in inflammation, tumorigenesis and metastasis. We were the first to uncover that cancer cells secrete sPLA2‑IIa. sPLA2‑IIa is overexpressed in almost all specimens of human lung cancers examined and is significantly elevated in the plasma of lung cancer patients. High levels of plasma sPLA2-IIa are significantly associated with advanced stage and decreased overall cancer survival. In this study, we further showed that elevated HER/HER2‑PI3K-Akt-NF-κB signaling contributes to sPLA2-IIa overexpression in lung cancer cells. sPLA2-IIa in turn phosphorylates and activates HER2 and HER3 in a time- and dose‑dependent manner in lung cancer cells. The structure and sequence‑based docking analysis revealed that sPLA2-IIa β hairpin shares structural similarity with the corresponding EGF hairpin. sPLA2-IIa forms an extensive interface with EGFR and brings the two lobes of EGFR into an active conformation. sPLA2-IIa also enhances the NF-κB promoter activity. Anti-sPLA2-IIa antibody, but not the small molecule sPLA2-IIa inhibitor LY315920, significantly inhibits sPLA2‑IIa-induced activation of NF-κB promoter. Our findings support the notion that sPLA2-IIa functions as a ligand for the EGFR family of receptors leading to an elevated HER/HER2-elicited signaling. Plasma sPLA2-IIa can potentially serve as lung cancer biomarker and sPLA2‑IIa is a potential therapeutic target against lung cancer.

Everolimus prolonged survival in transgenic mice with EGFR-driven lung tumors

Everolimus is an orally administered mTOR inhibitor. The effect, and mechanism of action, of everolimus on lung cancers with an epidermal growth factor receptor (EGFR) mutation remain unclear. Four gefitinib-sensitive and -resistant cell lines were used in the present work. Growth inhibition was determined using the MTT assay. Transgenic mice carrying the EGFR L858R mutation were treated with everolimus (10 mg/kg/day), or vehicle alone, from 5 to 20 weeks of age, and were then sacrificed. To evaluate the efficacy of everolimus in prolonging survival, everolimus (10 mg/kg/day) or vehicle was administered from 5 weeks of age. The four cell lines were similarly sensitive to everolimus. Expression of phosphorylated (p) mTOR and pS6 were suppressed upon treatment with everolimus in vitro, whereas the pAKT level increased. The numbers of lung tumors with a long axis exceeding 1mm in the everolimus-treated and control groups were 1.9 ± 0.9 and 9.4 ± 3.2 (t-test, p<0.001), respectively. pS6 was suppressed during eve r olimus treatment. Although apoptosis and autophagy were not induced in everolimus-treated EGFR transgenic mice, angiogenesis was suppressed. The median survival time in the everolimus-treated group (58.0 weeks) was significantly longer than that in the control group (31.2 weeks) (logrank test, p<0.001). These findings suggest that everolimus had an indirect effect on tumor formation by inhibiting angiogenesis and might be effective to treat lung tumors induced by an activating EGFR gene mutation.

Cortactin expression confers a more malignant phenotype to gastric cancer SGC-7901 cells

AIM: To study the effects of cortactin on the tumor biology of SGC-7901 cells and identify the mechanism involved in the process.

METHODS: Cell lines in which cortactin was stably overexpressed or knocked down as well as the respective control cell lines were established by standard molecular methods. The effects of cortactin on the proliferation, migration and invasion capacity of SGC-7901 cells were assessed by the MTT assay, colony formation, flow cytometry, transwell migration and matrigel invasion. Nude mouse models were also used to assess the role of cortactin in the growth and metastasis of SGC-7901 cells in vivo. Western blotting analysis was performed to detect the expression of epidermal growth factor receptor (EGFR) and downstream molecules.

RESULTS: Cell lines in which cortactin was stably overexpressed or knocked down as well as control cell lines were successfully established and designated as LV5-cortactin-SGC, LV5-SGC, LV3-shRNA-SGC and LV3-SGC. Cortactin overexpression promoted SGC-7901 cell migration (340.7 ±12.6 vs 229.1 ± 23.2, P < 0.01) and invasion (71.6 ± 5.2 vs 48.4 ± 3.6, P < 0.01). Cortactin downregulation impaired SGC-7901 cell migration (136.2 ± 19.8 vs 225 ± 17) and invasion (29.2 ± 5.2 vs 49.6 ± 3.8, P < 0.01). The results from the MTT and colony formation assays results indicated increased LV5-cortactin-SGC cell proliferation and decreased LV3-shRNA-SGC cell proliferation compared to the control cells. Flow cytometry analysis demonstrated that cortactin overexpression promoted the proliferation index of SGC-7901 cells, and the results were reversed when cortactin was downregulated. Mouse tumor models confirmed that cortactin expression increased SGC-7901 cell proliferation and metastasis in vivo. Western blotting analysis revealed that cortactin elevated EGFR expression and activated the downstream molecules.

CONCLUSION: Cortactin expression promoted the migration, invasion and proliferation of SGC-7901 cells both in vivo and in vitro. The EGFR signaling pathway is mechanistically involved.

High-density lipoprotein cholesterol is a favorable prognostic factor and negatively correlated with C-reactive protein level in non-small cell lung carcinoma

Background

Although the alterations of lipid profile in lung cancer have been documented, the prognostic value of serum HDL-C level and its correlation with inflammation in NSCLC remain unknown.

Subjects and Methods

Levels of preoperative serum lipid concentrations (including HDL-C, LDL-C, TC, and TG) and the inflammatory biomarker C-reactive protein level (CRP) were retrospectively analyzed in 228 patients with NSCLC and in 300 healthy controls. The serum lipid levels in these two populations were compared. Univariate and multivariate cox hazards analyses were performed to investigate the prognostic value of serum lipid levels in NSCLC. The correlation between CRP and lipid profile were also analyzed.

Results

Compared with those in normal controls, the serum HDL-C, LDL-C, and TC levels were statistically decreased and the TG levels were significantly increased in 228 NSCLC patients. The patients with decreased levels of HDL-C had significantly lower 5-year survival rates than those with normal HDL-C, not only in the whole NSCLC cohort but also in the subgroups stratified according to the disease T, N classifications, and metastasis, whereas the other lipid components were not independent prognostic factors for NSCLC. Of the lipid components, a lower HDL-C level was observed more often in patients with a high CRP level than in those with a normal CRP level. Spearman’s rank correlation analysis revealed that the HDL-C level presented a negative correlation with the CRP level (r = −0.360, p<0.001).

Conclusions

A decreased level of preoperative HDL-C was found to be associated with poor survival in patients with NSCLC. Serum HDL-C level may be a clinical prognosis factor for NSCLC patients. In addition, a negative correlation was present between the levels of HDL-C and CRP, the well-known inflammation biomarker.

Potential clinical predictors of outcome after postoperative radiotherapy of non-small cell lung cancer

AIM

The aim of this analysis was to investigate the impact of tumour-, treatment- and patient-related cofactors on local control and survival after postoperative adjuvant radiotherapy in patients with non-small cell lung cancer (NSCLC), with special focus on waiting and overall treatment times.

PATIENTS AND METHODS

For 100 NSCLC patients who had received postoperative radiotherapy, overall, relapse-free and metastases-free survival was retrospectively analysed using Kaplan-Meier methods. The impact of tumour-, treatment- and patient-related cofactors on treatment outcome was evaluated in uni- and multivariate Cox regression analysis.

RESULTS

No statistically significant difference between the survival curves of the groups with a short versus a long time interval between surgery and radiotherapy could be shown in uni- or multivariate analysis. Multivariate analysis revealed a significant decrease in overall survival times for patients with prolonged overall radiotherapy treatment times exceeding 42 days (16 vs. 36 months) and for patients with radiation-induced pneumonitis (8 vs. 29 months).

CONCLUSION

Radiation-induced pneumonitis and prolonged radiation treatment times significantly reduced overall survival after adjuvant radiotherapy in NSCLC patients. The negative impact of a longer radiotherapy treatment time could be shown for the first time in an adjuvant setting. The hypothesis of a negative impact of longer waiting times prior to commencement of adjuvant radiotherapy could not be confirmed.

Sex disparities in the association of lung adenocarcinoma with colorectal cancer

Background: Most cancers share common risk factors. It might provide evidence of shared risk factors with cancers by investigating cross-country and cross-township comparisons.

Methods: The data were obtained from International Association of Cancer Registries/World Health Organization and the National Cancer Registration Program of Taiwan. Age standardized incidence rates were calculated among gastric cancer, colorectal cancer and lung adenocarcinoma in 19 countries from 1995 to 1998. The Pearson correlations were also compared among 3 types of cancers for both sexes.

Results: The incidence rates of gastric and colorectal cancer throughout different countries show male dominance with a male-to-female sex ratio of around 2 and 1.5, respectively. Significant cross-country correlations in colorectal cancer (r=0.918, p<0.001), gastric cancer (r=0.985, p<0.001) and lung adenocarcinoma (r=0.685, p=0.001) were observed between men and women. There was a significant international correlation between colorectal cancer and lung adenocarcinoma in men (r=0.526, p=0.021), but not in women. In cross-township comparisons of Taiwan, there were significant correlations in colorectal cancer (r=0.451, p<0.001), gastric cancer (r=0.486, p<0.001), and lung adenocarcinoma (r=0.217, p<0.001) between men and women. There were links of lung adenocarcinoma and gastric cancer (r=0.122, p=0.024) and colorectal cancer (r=0.128, p=0.018) in women, and lung adenocarcinoma and colorectal cancer in men (r=0.276, p<0.001).

Conclusions: There were associations between lung adenocarcinoma and colorectal cancer between and in both sexes in Taiwan, but not in cross-country comparisons. The results suggest that some factor, like genes, may be important as determinants for the association between lung adenocarcinoma and colorectal cancer.

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.

The role of PTPN13 in invasion and metastasis of lung squamous cell carcinoma

OBJECTIVES

PTPN13 is a new candidate tumor-suppressing gene. To investigate the PTPN13 expression and its potential function in the invasion and metastasis of lung squamous cell carcinoma (LSCC), we performed this study in 91 primary LSCC tissues and the adjacent non-cancerous tissues.

METHODS

The mRNA expression of PTPN13 and FAK was quantitated by reverse transcription polymerase chain reaction. The protein expression of PTPN13, focal adhesion kinase (FAK) and phosphorylated FAK (P-FAK) was evaluated using immunohistochemical staining and western blotting. The association among PTPN13 expression, FAK expression and the clinicopathological parameters were analyzed.

RESULTS

PTPN13 expression was down-regulated in LSCC, and was negatively correlated with the cancer grade and stage. FAK mRNA, as well as FAK protein level was elevated in LSCC tissues. P-FAK level, also found increased, had no association with FAK mRNA and FAK protein expression, but had a negative correlation with the PTPN13 expression. P-FAK level had a significant positive correlation with the TNM classification.

CONCLUSION

The over-expression of FAK and increased FAK phosphorylation plays an important role in the invasion and metastasis of LSCC.

Targeted genetic dependency screen facilitates identification of actionable mutations in FGFR4, MAP3K9, and PAK5 in lung cancer

Approximately 70% of patients with non-small-cell lung cancer present with late-stage disease and have limited treatment options, so there is a pressing need to develop efficacious targeted therapies for these patients. This remains a major challenge as the underlying genetic causes of ~50% of non-small-cell lung cancers remain unknown. Here we demonstrate that a targeted genetic dependency screen is an efficient approach to identify somatic cancer alterations that are functionally important. By using this approach, we have identified three kinases with gain-of-function mutations in lung cancer, namely FGFR4, MAP3K9, and PAK5. Mutations in these kinases are activating toward the ERK pathway, and targeted depletion of the mutated kinases inhibits proliferation, suppresses constitutive activation of downstream signaling pathways, and results in specific killing of the lung cancer cells. Genomic profiling of patients with lung cancer is ushering in an era of personalized medicine; however, lack of actionable mutations presents a significant hurdle. Our study indicates that targeted genetic dependency screens will be an effective strategy to elucidate somatic variants that are essential for lung cancer cell viability.

Synergistic anticancer activity of arsenic trioxide with erlotinib is based on inhibition of EGFR-mediated DNA double-strand break repair

Arsenic trioxide (ATO), one of the oldest remedies used in traditional medicine, was recently rediscovered as an anticancer drug and approved for treatment of relapsed acute promyelocytic leukemia. However, its activity against nonhematologic cancers is rather limited so far. Here, we show that inhibition of ATO-mediated EGF receptor (EGFR) activation can be used to potently sensitize diverse solid cancer types against ATO. Thus, combination of ATO and the EGFR inhibitor erlotinib exerted synergistic activity against multiple cancer cell lines. Subsequent analyses revealed that this effect was based on the blockade of ATO-induced EGFR phosphorylation leading to more pronounced G2-M arrest as well as enhanced and more rapid induction of apoptosis. Comparable ATO-sensitizing effects were also found with PI3K/AKT and mitogen-activated protein/extracellular signal-regulated kinase (MEK) inhibitors, suggesting an essential role of the EGFR-mediated downstream signaling pathway in cancer cell protection against ATO. H2AX staining and comet assay revealed that erlotinib significantly increases ATO-induced DNA double-strand breaks (DSB) well in accordance with a role of the EGFR signaling axis in DNA damage repair. Indeed, EGFR inhibition led to downregulation of several DNA DSB repair proteins such as Rad51 and Rad50 as well as reduced phosphorylation of BRCA1. Finally, the combination treatment of ATO and erlotinib was also distinctly superior to both monotreatments against the notoriously therapy-resistant human A549 lung cancer and the orthotopic p31 mesothelioma xenograft model in vivo. In conclusion, this study suggests that combination of ATO and EGFR inhibitors is a promising therapeutic strategy against various solid tumors harboring wild-type EGFR.

A novel imidazopyridine PI3K inhibitor with anticancer activity in non-small cell lung cancer cells

Lung cancer is the leading cause of cancer-related mortality in the world, and non-small cell lung cancer (NSCLC) accounts for approximately 85% of all cases. Since more than 60% of NSCLC cases express the epidermal growth factor receptor (EGFR), EGFR tyrosine kinase inhibitors are used to treat NSCLC. However, due to the acquired resistance associated with EGFR-targeted therapy, other strategies for the treatment of NSCLC are urgently needed. Therefore, we investigated the anticancer effects of a novel phosphatidylinositol 3-kinase α (PI3Kα) inhibitor, HS-173, in human NSCLC cell lines. HS-173 demonstrated anti-proliferative effects in NSCLC cells and effectively inhibited the PI3K signaling pathway in a dose‑dependent manner. In addition, it induced cell cycle arrest at G2/M phase as well as apoptosis. Taken together, our results demonstrate that HS-173 exhibits anticancer activities, including the induction of apoptosis, by blocking the PI3K/Akt/mTOR pathway in human NSCLC cell lines. We, therefore, suggest that this novel drug could potentially be used for targeted NSCLC therapy.

Role of Epidermal Growth Factor Receptor Inhibitors in Epidermal Growth Factor Receptor Wild-Type Non–Small-Cell Lung Cancer

Worldwide, the majority of patients with advanced non–small-cell lung cancer (NSCLC) do not have activating mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR). These wild-type patients comprise a significant proportion of those treated with inhibitors of this pathway, and data from randomized trials suggest that some of these wild-type patients will derive a modest benefit from these agents. Although the detection of an activating mutation predicts for a greater likelihood of response and longer progression-free survival from an EGFR tyrosine kinase inhibitor, currently there are no biomarkers that consistently and reproducibly predict for lack of benefit in wild-type patients. Several strategies to increase the efficacy of these inhibitors in wild-type NSCLC are the subject of ongoing investigations.

Pathology and personalized medicine in lung cancer

SUMMARY Personalized medicine for patients with non-small-cell lung cancer is a reality now and its use will only increase in the future. Pathology is key in supporting this approach to treatment decision-making, by performing the most complete and accurate histological subtyping of tumors possible, supported by predictive immunohistochemistry and the assessment of relevant biomarkers. The need for these extra diagnostic steps emphasizes the importance of maximizing tissue yields from biopsy procedures. Although multiplex approaches may allow simultaneous assessment of several biomarkers, there will remain a need for different types of test (e.g., immunohistochemistry, as well as mutation testing). Next-generation technologies for DNA sequencing are a great hope for extensive genetic analysis of single samples, provided various technical and logistical problems can be solved. All such laboratory activity must be supported by high-quality internal procedures and external quality-assurance schemes.

The evolving role of the pathologist in the management of lung cancer

Major advances in pathology, molecular biology, patient diagnosis and care, as well as the advent of personalized therapy, have resulted in a greatly increased role for the pathologist, who has emerged as a key member of the lung cancer management team. A new multidisciplinary, clinically relevant classification of pulmonary adenocarcinoma has resulted in a paradigm shift in how we view and practice lung cancer pathology. In the future, the role of the pathologist will continue to grow and become fully integrated with clinical care.

Phosphorylated EGFR expression may predict outcome of EGFR-TKIs therapy for the advanced NSCLC patients with wild-type EGFR

Background

EGFR mutation is a strong predictive factor of EGFR-TKIs therapy. However, at least 10% of patients with EGFR wild-type are responsive to TKIs, suggesting that other determinants of outcome besides EGFR mutation might exist. We hypothesized that activation of phosphorylated EGFR could be a potential predictive biomarker to EGFR-TKIs treatment among patients in wild-type EGFR.

Method

Total of 205 stage IIIb and IV NSCLC patients, tissue samples of whom were available for molecular analysis, were enrolled in this study. The phosphorylation of EGFR at tyrosine 1068 (pTyr1068) and 1173 (pTyr1173) were assessed by immunohistochemistry, and EGFR mutations were detected by denaturing high performance liquid chromatograph (DHPLC).

Results

Among 205 patients assessable for EGFR mutation and phosphorylation analysis, 92 (44.9%) were EGFR mutant and 165 patients (57.6%) had pTyr1173 expression. Superior progression-free survival (PFS) was seen after EGFR-TKIs therapy in patients with pTyr1068 expression compared to pTyr1068 negative ones (median PFS 7.0 months vs. 1.2 months, P < 0.001). Inversely, patients with pTyr1173 had a shorter PFS (4.8 months VS. 7.7 months, P = 0.016). In subgroup of patients with wild-type EGFR, pTyr1068 expression positive ones had a significantly prolonged PFS (4.2 months vs.1.2 months P < 0.001) compared with those without pTyr1068 expression. Sixteen patients with both wild-type EGFR and pTyr1068 who responded to EGFR-TKIs had median PFS of 15.6 months (95%CI: 7.28-23.9).

Conclusion

pTyr1068 may be a predictive biomarker for screening the population for clinical response to EGFR-TKIs treatment; especially for patients with wild-type EGFR.

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.

PTRF/cavin-1 and MIF proteins are identified as non-small cell lung cancer biomarkers by label-free proteomics

With the completion of the human genome sequence, biomedical sciences have entered in the “omics” era, mainly due to high-throughput genomics techniques and the recent application of mass spectrometry to proteomics analyses. However, there is still a time lag between these technological advances and their application in the clinical setting. Our work is designed to build bridges between high-performance proteomics and clinical routine. Protein extracts were obtained from fresh frozen normal lung and non-small cell lung cancer samples. We applied a phosphopeptide enrichment followed by LC-MS/MS. Subsequent label-free quantification and bioinformatics analyses were performed. We assessed protein patterns on these samples, showing dozens of differential markers between normal and tumor tissue. Gene ontology and interactome analyses identified signaling pathways altered on tumor tissue. We have identified two proteins, PTRF/cavin-1 and MIF, which are differentially expressed between normal lung and non-small cell lung cancer. These potential biomarkers were validated using western blot and immunohistochemistry. The application of discovery-based proteomics analyses in clinical samples allowed us to identify new potential biomarkers and therapeutic targets in non-small cell lung cancer.