Paradigm of kinase-driven pathway downstream of epidermal growth factor receptor/Akt in human lung carcinomas

The potential role of circular RNAs -regulated PI3K signaling in non-small cell lung cancer: Molecular insights and clinical perspective

Non-small cell lung cancer (NSCLC), accounting for more than 80% of all cases, is the predominant form of lung cancer and the leading cause of cancer-related deaths worldwide. Significant progress has been made in diagnostic techniques, surgical interventions, chemotherapy protocols, and targeted therapies at the molecular level, leading to enhanced treatment outcomes in patients with NSCLC. Extensive evidence supports the use of circular RNAs (circRNAs), a specific category of naturally occurring non-coding small RNAs (ncRNAs), for the diagnosis, monitoring of treatment efficacy, and assessment of survival in NSCLC. CircRNAs have been identified to play significant roles in various aspects of cancer formation, either as tumor suppressors or tumor promoters, contributing to cancer development through several signaling pathways, including the phosphoinositide 3-kinases (PI3Ks) pathway. This pathway is well-established because of its regulatory role in essential cellular processes. CircRNAs regulate the PI3K/AKT pathway by targeting diverse cellular elements. This review aims to provide insight into the involvement of several circRNAs linked to the PI3K/AKT pathway in NSCLC.

Molecular Targeting of the Phosphoinositide-3-Protein Kinase (PI3K) Pathway across Various Cancers

The dysregulation of the phosphatidylinositol-3-kinase (PI3K) pathway can lead to uncontrolled cellular growth and tumorigenesis. Targeting PI3K and its downstream substrates has been shown to be effective in preclinical studies and phase III trials with the approval of several PI3K pathway inhibitors by the Food and Drug Administration (FDA) over the past decade. However, the limited clinical efficacy of these inhibitors, intolerable toxicities, and acquired resistances limit the clinical application of PI3K inhibitors. This review discusses the PI3K signaling pathway, alterations in the PI3K pathway causing carcinogenesis, current and novel PI3K pathway inhibitors, adverse effects, resistance mechanisms, challenging issues, and future directions of PI3K pathway inhibitors.

KCNAB2 overexpression inhibits human non-small-cell lung cancer cell growth in vitro and in vivo

Non-small-cell lung cancer (NSCLC) accounts for approximately 85% of all lung cancer cases. NSCLC patients often have poor prognosis demanding urgent identification of novel biomarkers and potential therapeutic targets. KCNAB2 (regulatory beta subunit2 of voltage-gated potassium channel), encoding aldosterone reductase, plays a pivotal role in regulating potassium channel activity. In this research, we tested the expression of KCNAB2 as well as its potential functions in human NSCLC. Bioinformatics analysis shows that expression of KCNAB2 mRNA is significantly downregulated in human NSCLC, correlating with poor overall survival. In addition, decreased KCNAB2 expression was detected in different NSCLC cell lines and local human NSCLC tissues. Exogenous overexpression of KCNAB2 potently suppressed growth, proliferation and motility of established human NSCLC cells and promoted NSCLC cells apoptosis. In contrast, CRISPR/Cas9-induced KCNAB2 knockout further promoted the malignant biological behaviors of NSCLC cells. Protein chip analysis in the KCNAB2-overexpressed NSCLC cells revealed that KCNAB2 plays a possible role in AKT-mTOR cascade activation. Indeed, AKT-mTOR signaling activation was potently inhibited following KCNAB2 overexpression in NSCLC cells. It was however augmented by KCNAB2 knockout. In vivo, the growth of subcutaneous KCNAB2-overexpressed A549 xenografts was significantly inhibited. Collectively, KCNAB2 could be a novel effective gene for prognosis prediction of NSCLC. Targeting KCNAB2 may lead to the development of advanced therapies.

Implication of mTOR Signaling in NSCLC: Mechanisms and Therapeutic Perspectives

Mechanistic target of the rapamycin (mTOR) signaling pathway represents a central cellular kinase that controls cell survival and metabolism. Increased mTOR activation, along with upregulation of respective upstream and downstream signaling components, have been established as oncogenic features in cancer cells in various tumor types. Nevertheless, mTOR pathway therapeutic targeting has been proven to be quite challenging in various clinical settings. Non-small cell lung cancer (NSCLC) is a frequent type of solid tumor in both genders, where aberrant regulation of the mTOR pathway contributes to the development of oncogenesis, apoptosis resistance, angiogenesis, cancer progression, and metastasis. In this context, the outcome of mTOR pathway targeting in clinical trials still demonstrates unsatisfactory results. Herewith, we discuss recent findings regarding the mechanisms and therapeutic targeting of mTOR signaling networks in NSCLC, as well as future perspectives for the efficient application of treatments against mTOR and related protein molecules.

FERM domain-containing protein FRMD6 activates the mTOR signaling pathway and promotes lung cancer progression

FRMD6, a member of the 4.1 ezrin-radixin-moesin domain-containing protein family, has been reported to inhibit tumor progression in multiple cancers. Here, we demonstrate the involvement of FRMD6 in lung cancer progression. We find that FRMD6 is overexpressed in lung cancer tissues relative to in normal lung tissues. In addition, the enhanced expression of FRMD6 is associated with poor outcomes in patients with lung squamous cell carcinoma (n = 75, P = 0.0054) and lung adenocarcinoma (n = 94, P = 0.0330). Cell migration and proliferation in vitro and tumor formation in vivo are promoted by FRMD6 but are suppressed by the depletion of FRMD6. Mechanistically, FRMD6 interacts and colocalizes with mTOR and S6K, which are the key molecules of the mTOR signaling pathway. FRMD6 markedly enhances the interaction between mTOR and S6K, subsequently increasing the levels of endogenous pS6K and downstream pS6 in lung cancer cells. Furthermore, knocking out FRMD6 inhibits the activation of the mTOR signaling pathway in Frmd6-/- gene KO MEFs and mice. Altogether, our results show that FRMD6 contributes to lung cancer progression by activating the mTOR signaling pathway.

mTOR Inhibition Is Effective against Growth, Survival and Migration, but Not against Microglia Activation in Preclinical Glioma Models

Initially introduced in therapy as immunosuppressants, the selective inhibitors of mTORC1 have been approved for the treatment of solid tumors. Novel non-selective inhibitors of mTOR are currently under preclinical and clinical developments in oncology, attempting to overcome some limitations associated with selective inhibitors, such as the development of tumor resistance. Looking at the possible clinical exploitation in the treatment of glioblastoma multiforme, in this study we used the human glioblastoma cell lines U87MG, T98G and microglia (CHME-5) to compare the effects of a non-selective mTOR inhibitor, sapanisertib, with those of rapamycin in a large array of experimental paradigms, including (i) the expression of factors involved in the mTOR signaling cascade, (ii) cell viability and mortality, (iii) cell migration and autophagy, and (iv) the profile of activation in tumor-associated microglia. We could distinguish between effects of the two compounds that were overlapping or similar, although with differences in potency and or/time-course, and effects that were diverging or even opposite. Among the latter, especially relevant is the difference in the profile of microglia activation, with rapamycin being an overall inhibitor of microglia activation, whereas sapanisertib was found to induce an M2-profile, which is usually associated with poor clinical outcomes.

The clinicopathological and prognostic significance of mTOR and p-mTOR expression in patients with non-small cell lung cancer: A meta-analysis

BACKGROUND

The mammalian target of rapamycin (mTOR) has a crucial role in carcinogenesis, angiogenesis, cellular proliferation, and metastasis; however, its significance in non-small cell lung cancer (NSCLC) remains contentious. Consequently, this study aims to assess the clinicopathological and prognostic importance of mTOR/p-mTOR expression in NSCLC.

METHODS

Literature retrieval was undertaken by searching English databases PubMed, EMBASE, Web of Science, and Cochrane Library as well as Chinese databases CNKI, Wan Fang, and VIP for full-text publications that satisfied our eligibility criteria up to November 2021. STATA 12.0 was used to conduct statistical analysis (STATA Corporation, College Station, TX).

RESULTS

This meta-analysis includes a total of 4683 patients from 28 primary publications. mTOR/p-mTOR expression was associated with sex (OR = 0.608, 95% CI: 0.442-0.836), lymph node metastasis (OR = 2.084, 95% CI: 1.437-3.182), and CEA (OR = 1.584, 95% CI: 1.135-2.209), but not with age, histological type, depth of tumor invasion, distant metastasis, TNM stage, differentiation degree, tumor size, or smoking. In addition, the expression of mTOR/p-mTOR is related to shorter overall survival in NSCLC patients (HR = 1.415, 95% CI: 1.051-1.905).

CONCLUSION

Positive mTOR/p-mTOR expression was substantially correlated with unfavorable conditions on the sex, lymph node metastases, and CEA levels. mTOR/p-mTOR may indicate a bad prognosis for NSCLC. The current findings must be confirmed and changed by other high-quality research employing a multivariate analysis on bigger sample size.

[Research Progress on Pathogenic Mechanism and Potential Therapeutic Drugs of Idiopathic Pulmonary Fibrosis Complicated with Non-small Cell Lung Cancer]

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive fibrous interstitial lung disease of unknown etiology. IPF is also considered to be among the independent risk factors for lung cancer, increasing the risk of lung cancer by 7% and 20%. The incidence of IPF complicated with lung cancer, especially non-small cell lung cancer (NSCLC), is increasing gradually, but there is no consensus on unified management and treatment. IPF and NSCLC have similar pathological features. Both appear in the surrounding area of the lung. In pathients with IPF complicated with NSCLC, NSCLC often develops from the honeycomb region of IPF, but the mechanism of NSCLC induced by IPF remains unclear. In addition, IPF and NSCLC have similar genetic, molecular and cellular processes and common signal transduction pathways. The universal signal pathways targeting IPF and NSCLC will become potential therapeutic drugs for IPF complicated with NSCLC. This article examines the main molecular mechanisms involved in IPF and NSCLC and the research progress of drugs under development targeting these signal pathways.
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Cathepsin K: A Versatile Potential Biomarker and Therapeutic Target for Various Cancers

Cancer, a common malignant disease, is one of the predominant causes of diseases that lead to death. Additionally, cancer is often detected in advanced stages and cannot be radically cured. Consequently, there is an urgent need for reliable and easily detectable markers to identify and monitor cancer onset and progression as early as possible. Our aim was to systematically review the relevant roles of cathepsin K (CTSK) in various possible cancers in existing studies. CTSK, a well-known key enzyme in the bone resorption process and most studied for its roles in the effective degradation of the bone extracellular matrix, is expressed in various organs. Nowadays, CTSK has been involved in various cancers such as prostate cancer, breast cancer, bone cancer, renal carcinoma, lung cancer and other cancers. In addition, CTSK can promote tumor cells proliferation, invasion and migration, and its mechanism may be related to RANK/RANKL, TGF-β, mTOR and the Wnt/β-catenin signaling pathway. Clinically, some progress has been made with the use of cathepsin K inhibitors in the treatment of certain cancers. This paper reviewed our current understanding of the possible roles of CTSK in various cancers and discussed its potential as a biomarker and/or novel molecular target for various cancers.

Targeting sphingosine kinase 1/2 by a novel dual inhibitor SKI-349 suppresses non-small cell lung cancer cell growth

Sphingosine kinase 1 (SphK1) and sphingosine kinase (SphK2) are both important therapeutic targets of non-small cell lung cancer (NSCLC). SKI-349 is a novel, highly efficient and small molecular SphK1/2 dual inhibitor. Here in primary human NSCLC cells and immortalized cell lines, SKI-349 potently inhibited cell proliferation, cell cycle progression, migration and viability. The dual inhibitor induced mitochondrial depolarization and apoptosis activation in NSCLC cells, but it was non-cytotoxic to human lung epithelial cells. SKI-349 inhibited SphK activity and induced ceramide accumulation in primary NSCLC cells, without affecting SphK1/2 expression. SKI-349-induced NSCLC cell death was attenuated by sphingosine-1-phosphate and by the SphK activator K6PC-5, but was potentiated by the short-chain ceramide C6. Moreover, SKI-349 induced Akt-mTOR inactivation, JNK activation, and oxidative injury in primary NSCLC cells. In addition, SKI-349 decreased bromodomain-containing protein 4 (BRD4) expression and downregulated BRD4-dependent genes (Myc, cyclin D1 and Klf4) in primary NSCLC cells. At last, SKI-349 (10 mg/kg) administration inhibited NSCLC xenograft growth in nude mice. Akt-mTOR inhibition, JNK activation, oxidative injury and BRD4 downregulation were detected in SKI-349-treated NSCLC xenograft tissues. Taken together, targeting SphK1/2 by SKI-349 potently inhibits NSCLC cell growth in vitro and in vivo.

Urinary exosomal long noncoding RNAs serve as biomarkers for early detection of non-small cell lung cancer

Objective: Increasing the efficiency of early diagnosis using noninvasive biomarkers is crucial for enhancing the survival rate of lung cancer patients. We explore the differential expression of non-small cell lung cancer (NSCLC)-related long noncoding RNAs (lncRNAs) in urinary exosomes in NSCLC patients and normal controls to diagnose lung cancer.

Methods: A differential expression analysis between NSCLC patients and healthy controls was performed using microarrays. Gene ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to predict potential functions of lncRNAs in NSCLC. quantitative real-time PCR (QT-PCR) was used to verify microarray results.

Results: A total of 640 lncRNAs (70 up- and 570 down-regulated) were differentially expressed in NSCLC patients in comparison to healthy controls. Six lncRNAs were detected by QT-PCR. GO term and KEGG pathway analyses showed that differential lncRNAs were enriched in cellular component organization or biogenesis, as well as other biological processes and signaling pathways, such as the PI3K-AKT, FOXO, p53, and fatty acid biosynthesis.

Conclusions: The differential lncRNAs in urinary exosomes are potential diagnostic biomarkers of NSCLC. The lncRNAs enriched in specific pathways may be associated with tumor cell proliferation, tumor cell apoptosis, and the cell cycle involved in the pathogenesis of NSCLC.

The Anti-Non-Small Cell Lung Cancer Cell Activity by a mTOR Kinase Inhibitor PQR620

In non-small-cell lung carcinoma (NSCLC), aberrant activation of mammalian target of rapamycin (mTOR) contributes to tumorigenesis and cancer progression. PQR620 is a novel and highly-potent mTOR kinase inhibitor. We here tested its potential activity in NSCLC cells. In primary human NSCLC cells and established cell lines (A549 and NCI-H1944), PQR620 inhibited cell growth, proliferation, and cell cycle progression, as well as cell migration and invasion, while inducing significant apoptosis activation. PQR620 disrupted assembles of mTOR complex 1 (mTOR-Raptor) and mTOR complex 2 (mTOR-Rictor-Sin1), and blocked Akt, S6K1, and S6 phosphorylations in NSCLC cells. Restoring Akt-mTOR activation by a constitutively-active Akt1 (S473D) only partially inhibited PQR620-induced cytotoxicity in NSCLC cells. PQR620 was yet cytotoxic in Akt1/2-silenced NSCLC cells, supporting the existence of Akt-mTOR-independent mechanisms. Indeed, PQR620 induced sphingosine kinase 1 (SphK1) inhibition, ceramide production and oxidative stress in primary NSCLC cells. In vivo studies demonstrated that daily oral administration of a single dose of PQR620 potently inhibited primary NSCLC xenograft growth in severe combined immune deficient mice. In PQR620-treated xenograft tissues, Akt-mTOR inactivation, apoptosis induction, SphK1 inhibition and oxidative stress were detected. In conclusion, PQR620 exerted potent anti-NSCLC cell activity via mTOR-dependent and -independent mechanisms.

Baicalein suppresses growth of non-small cell lung carcinoma by targeting MAP4K3

Exploring key genes associated with non-small cell lung carcinoma (NSCLC) may lead to targeted therapies for NSCLC patients. The protein kinase MAP4K3 has been established as an important modulator of cell growth and autophagy in mammals. Herein, we investigated the somatic mutations and the expression pattern of MAP4K3 detected in NSCLC patients based on the TCGA database. Abnormal MAP4K3 expression and its somatic mutations are associated with the carcinogenesis and thereby becoming an attractive therapeutic target. Baicalein, a natural product, was determined to be the first-reported MAP4K3 binding ligand with its KD values of 6.47 μM measured by microscale thermophoresis. Subsequent in silico docking and mutation studies demonstrated that baicalein directly binds to MAP4K3, presumably to the substrate-binding pocket of this kinase domain, causing inactivity of MAP4K3. We further showed that baicalein could induce degradation of MAP4K3 through decreasing its stability and promoting the ubiquitin proteasome pathway. Degradation of MAP4K3 could cause dissociation of the transcription factor EB and 14-3-3 complex, enhance rapid transport of TFEB to the nucleus and trigger TFEB-dependent autophagy, resulting in lung cancer cells proliferation arrest. Knockdown of MAP4K3 expression by siRNA was sufficient to mimic baicalein-induced autophagy. Ectopic expression of the MAP4K3 protein resulted in significant resistance to baicalein-induced autophagy. Baicalein exhibited good tumor growth inhibition in a nude mouse model for human H1299 xenografts, which might be tightly related to its binding to MAP4K3 and degradation of MAP4K3. Our data provide novel mechanistic insights of baicalein/ MAP4K3/ mTORC1/ TFEB axis in regulating baicalein-induced autophagy in NSCLC, suggesting potential therapies for treatment of NSCLC.

Effects of hyperinsulinemia on acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitor via the PI3K/AKT pathway in non-small cell lung cancer cells in vitro

Patients with lung cancer harboring activating epidermal growth factor (EGFR) mutations and pre-existing diabetes have been demonstrated to exhibit poor responses to first-line EGFR-tyrosine kinase inhibitor (TKI) therapy. Strategies for the management of acquired resistance to EGFR-TKIs in patients with advanced non-small cell lung cancer (NSCLC) are urgently required. Only a limited number of studies have been published to date on the effects of insulin on EGFR-TKI resistance in NSCLC. Hence, the aim of the present study was to investigate the roles of hyperinsulinemia and hyperglycemia in mediating gefitinib resistance in NSCLC cells with activating EGFR mutations. In the present study, the HCC4006 cell line, which harbors EGFR mutations, was co-treated with gefitinib and long-acting insulin glargine. Whether hyperinsulinemia is able to mediate EGFR-TKI resistance in the NSCLC cell line harboring activating EGFR mutations was also investigated, and the possible underlying mechanisms responsible for these actions were explored. The inhibition of cell proliferation, and the potential mechanism of gefitinib resistance, were examined using an MTS proliferation assay and western blot analysis, and through the transfection of siRNAs. Whether the inhibition of AKT is able to overcome EGFR-TKI resistance induced by long-acting insulin was also investigated. The results obtained suggested that hyperinsulinemia induced by glargine upregulated NSCLC cell proliferation and survival, and induced gefitinib resistance. By contrast, the morphology and proliferation of the cells in a medium containing a 2-fold concentration of glucose were not significantly affected. Gefitinib resistance induced by hyperinsulinemia may have been mediated via the phosphoinositide 3-kinase (PI3K)/AKT pathway rather than the mitogen-activated protein kinase extracellular signal regulated kinase (MAPK/ERK) pathway. AKT serine/threonine kinase 1 knockdown by siRNA rescued the gefitinib resistance that was induced by hyperinsulinemia. In conclusion, hyperinsulinemia, but not hyperglycemia, was identified to cause the development of gefitinib resistance in NSCLC cells with activating EGFR mutations. However, additional studies are required to investigate strategies, such as co targeting hyperinsulinemia and the PI3K/AKT pathway, for overcoming EGFR-TKI resistance in patients with NSCLC.

EGFR/c-Met and mTOR signaling are predictors of survival in non-small cell lung cancer

BACKGROUND

EGFR/c-Met activation/amplification and co-expression, mTOR upregulation/activation, and Akt/Wnt signaling upregulation have been individually associated with more aggressive disease and characterized as potential prognostic markers for lung cancer patients.

METHODS

Tumors obtained from 109 participants with stage I-IV non-small cell lung cancer (NSCLC) were studied for EGFR/c-Met co-localization as well as for total and active forms of EGFR, c-Met, mTOR, S6K, beta-catenin, and Axin2. Slides were graded by two independent blinded pathologists using a validated scoring system. Protein expression profile correlations were assessed using Pearson correlation and Spearman's rho. Prognosis was assessed using Kaplan-Meier analysis.

RESULTS

Protein expression profile analysis revealed significant correlations between EGFR/p-EGFR (p = 0.0412) and p-mTOR/S6K (p = 0.0044). Co-localization of p-EGFR/p-c-Met was associated with increased p-mTOR (p = 0.0006), S6K (p = 0.0018), and p-S6K (p < 0.0001) expression. In contrast, active beta-catenin was not positively correlated with EGFR/c-Met nor any activated proteins. Axin2, a negative regulator of the Wnt pathway, was correlated with EGFR, p-EGFR, p-mTOR, p-S6K, EGFR/c-Met co-localization, and p-EGFR/p-c-Met co-localization (all p-values <0.03). Kaplan-Meier analysis revealed shorter median survival in participants with high expression of Axin2, total beta-catenin, total/p-S6K, total/p-mTOR, EGFR, and EGFR/c-Met co-localization compared with low expression. After controlling for stage of disease at diagnosis, subjects with late-stage disease demonstrated shorter median survival when exhibiting high co-expression of EGFR/c-Met (8.1 month versus 22.3 month, p = 0.050), mTOR (6.7 month versus 22.3 month, p = 0.002), and p-mTOR (8.1 month versus 25.4 month, p = 0.004) compared with low levels.

CONCLUSIONS

These findings suggest that increased EGFR/c-Met signaling is correlated with upregulated mTOR/S6K signaling, which may in turn be associated with shorter median survival in late-stage NSCLC.

The Potential Role of Cathepsin K in Non-Small Cell Lung Cancer

(1) Background: Cathepsin K has been found overexpressed in several malignant tumors. However, there is little information regarding the involvement of Cathepsin K in non-small cell lung cancer (NSCLC). (2) Methods: Cathepsin K expression was tested in human NSCLC cell lines A549 and human embryo lung fibroblast MRC-5 cells using Western blot and immunofluorescence assay. Cathepsin K was transiently overexpressed or knocked down using transfection with a recombinant plasmid and siRNA, respectively, to test the effects on cell proliferation, migration, invasion, and on the mammalian target of rapamycin (mTOR) signaling pathway. (3) Results: Expression of Cathepsin K was increased significantly in A549 cells and diffused within the cytoplasm compared to the MRC-5 cells used as control. Cathepsin K overexpression promoted the proliferation, migration, and invasion of A549 cells, accompanied by mTOR activation. Cathepsin K knockdown reversed the above malignant behavior and inhibited the mTOR signaling activation, suggesting that Cathepsin K may promote the progression of NSCLC by activating the mTOR signaling pathway. (4) Conclusion: Cathepsin K may potentially represent a viable drug target for NSCLC treatment.

Targeting the PI3K/Akt/mTOR pathway in non-small cell lung cancer (NSCLC)

The traditional classification of lung cancer into small cell lung cancer and non‐small cell lung cancer (NSCLC) has been transformed with the increased understanding of the molecular alterations and genomic biomarkers that drive the development of lung cancer. Increased activation of the phosphatidylinositol 3‐kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) pathway leads to numerous hallmarks of cancer and this pathway represents an attractive target for novel anticancer therapies. In NSCLC, the PI3K/Akt/mTOR pathway has been heavily implicated in both tumorigenesis and the progression of disease. A number of specific inhibitors of PI3K, Akt and mTOR are currently under development and in various stages of preclinical investigation and in early phase clinical trials for NSCLC. Early evidence has yielded disappointing results. Clinical trials, however, have been performed on predominantly molecularly unselected populations, and patient enrichment strategies using high‐precision predictive biomarkers in future trials will increase the likelihood of success. A greater understanding of the underlying molecular biology including epigenetic alterations is also crucial to allow for the detection of appropriate biomarkers and guide combination approaches.

A clinicopathological study of parotid carcinoma: 18-year review of 171 patients at a single institution

BACKGROUND

This study investigated the clinical outcomes of patients with parotid carcinoma at a single institution during an 18-year period, with the focus on diagnosis, treatment, and survival.

METHODS

The subjects were 171 patients with parotid carcinoma treated at our department during the 18-year period from September 1999 to August 2017. There were 19 patients in stage I, 65 patients in stage II, 22 patients in stage III, and 65 patients in stage IV. The symptoms, preoperative diagnosis, node metastasis, survival rate, prognostic factors, and immunohistological findings were investigated.

RESULTS

Preoperative diagnosis of the histological grade by fine-needle aspiration cytology was only possible in 34% of the patients, while the histological grade was correctly determined by frozen section biopsy in 72%. The overall frequency of lymph node metastasis was 29%, with 59% in patients with high-grade carcinoma and only 6% in those with low-/intermediate-grade tumors. The disease-specific 5-year survival rate was 100% for patients in stage I, 95.2% in stage II, 70.4% in stage III, and 45.1% in stage IV. Multivariate analysis showed that the pathological grade was the most important prognostic factor. Immunohistological investigation showed patients with HER-2 or androgen receptor-positive tumors had a significantly worse prognosis.

CONCLUSIONS

Although a high-grade tumor is the most important prognostic factor, preoperative diagnosis of the grade was not always accurate. Since advanced cancer has a poor prognosis with a limited response to surgery and radiation therapy, development of new treatment strategies, such as molecular-targeting therapies directed against HER-2 and AR, is required.

Expression of mTORC1/2-related proteins in primary and brain metastatic lung adenocarcinoma

Brain metastases (BMs) are common complications of adenocarcinomas (ADCs) of the lung and are associated with a poor prognosis. Although an increasing amount of data indicates that dysregulated activity of mammalian target of rapamycin (mTOR) can influence the metastatic potential of various tumors, the role of mTOR complexes in the development of BMs from ADCs of the lung is largely unknown. To estimate mTOR activity, we studied the expression of mTOR-related proteins (mTORC1: p-mTOR, p-S6; mTORC2: p-mTOR, Rictor) in primary (n=67) and brain metastatic (n=67) lung ADCs, including 15 paired tissue samples, using immunohistochemistry and tissue microarrays. Correlation with clinicopathological parameters was also analyzed. Increased p-mTOR, p-S6, and Rictor expressions were observed in 34%, 33%, and 37% of primary ADCs and in 79%, 70%, and 66% of BMs, respectively. Expression of these markers was significantly higher in BMs as compared with primary carcinomas (P<.0001, P<.0001, P<.001). Rictor expression was significantly higher in primary ADCs of the paired cases with BMs as compared with primary ADCs without BMs (67% versus 28%; P<.01). No other statistically significant correlations were found between mTOR activity and clinicopathological parameters. The increased mTORC1/C2 activity in a subset of pulmonary ADCs and the higher incidence of increased mTORC1/C2 activity in BMs suggest that the immunohistochemistry panel for characterizing mTOR activity and its potential predictive and prognostic role warrants further investigations.

Expression profiling of receptor tyrosine kinases in high-grade neuroendocrine carcinoma of the lung: a comparative analysis with adenocarcinoma and squamous cell carcinoma

Background

As the comprehensive genomic analysis of small cell lung cancer (SCLC) progresses, novel treatments for this disease need to be explored. With attention to the direct connection between the receptor tyrosine kinases (RTKs) of tumor cells and the pharmacological effects of specific inhibitors, we systematically assessed the RTK expressions of high-grade neuroendocrine carcinomas of the lung [HGNECs, including SCLC and large cell neuroendocrine carcinoma (LCNEC)].

Patients and methods

Fifty-one LCNEC and 61 SCLC patients who underwent surgical resection were enrolled in this research. As a control group, 202 patients with adenocarcinomas (ADCs) and 122 patients with squamous cell carcinomas (SQCCs) were also analyzed. All the tumors were stained with antibodies for 10 RTKs: c-Kit, EGFR, IGF1R, KDR, ERBB2, FGFR1, c-Met, ALK, RET, and ROS1.

Results

The LCNEC and SCLC patients exhibited similar clinicopathological characteristics. The IHC scores for each RTK were almost equivalent between the LCNEC and SCLC groups, but they were significantly different from those of the ADC or SQCC groups. In particular, c-Kit was the only RTK that was remarkably expressed in both LCNECs and SCLCs. On the other hand, about 20 % of the HGNEC tumors exhibited strongly positive RTK expression, and this rate was similar to those for the ADC and SQCC tumors. Intriguingly, strongly positive RTKs were almost mutually exclusive in individual tumors.

Conclusions

Compared with ADC or SQCC, LCNEC and SCLC had similar expression profiles for the major RTKs. The exclusive c-Kit positivity observed among HGNECs suggests that c-Kit might be a distinctive RTK in HGNEC.

Electronic supplementary material

The online version of this article (doi:10.1007/s00432-015-1989-z) contains supplementary material, which is available to authorized users.

Diverse involvement of isoforms and gene aberrations of Akt in human lung carcinomas

Emerging evidence confirms a central role of Akt in cancer. To evaluate the relative contribution of deregulated Akt and their clinicopathological significance in lung carcinomas, overexpression, activation of Akt and AKT gene increases were investigated. Immunohistochemical staining for 108 cases revealed overexpression of total Akt, Akt1, Akt2 and Akt3 in 61.1, 47.2, 40.7 and 23.1%, respectively, and phosphorylated Akt in 42.6% of cases. Expression of total Akt, Akt2 and Akt3 were frequently observed in small cell carcinoma, but phosphorylated Akt and Akt1 were more frequently observed in squamous cell carcinoma. FISH analysis to evaluate gene increases of AKT1-3 revealed amplification of AKT1 in 4.2% and AKT1 increase by polysomy of chromosome 14 in 27.3% of cases. For AKT2, amplification was observed in 3.2% and polysomy of chromosome 19 in 26.3% of cases. AKT3 increase was observed in 40.0% of cases only by polysomy of chromosome 1. Although “FISH-positive” AKT1 and AKT2 gene increases (amplification/high-level polysomy) were found exclusively in the cases overexpressing total Akt, Akt1 or Akt2, respectively, AKT3 increase was irrelevant of Akt3 expression. Statistically, expressions of Akt2, p-Akt and cytoplasmic-p-Akt were correlated with lymph node metastasis (P = 0.0479, P = 0.0371 and P = 0.0310, respectively). Although AKT1 and AKT2 gene increase showed positive correlation with, or trend towards a positive correlation with tumor size (P = 0.0430, P = 0.0590, respectively), AKT3 did not. In conclusion, Akt isoforms are differentially involved in the pathological phenotype of lung carcinoma in a diverse manner. Because abnormality of Akt1/AKT1 and Akt2/AKT2 correlated with clinicopathological profiles, Akt1/2-specific targeting may open a novel therapeutic window for the group showing Akt deregulation.

Immunohistochemical characterization of the mTOR pathway in stage-I non-small-cell lung carcinoma

BACKGROUND

Dysregulation of mammalian target of rapamycin (mTOR) pathway has been linked with malignant tumorigenesis. This study explored the expression profiles of proteins involved in the mTOR pathway and their relationships with clinicopathologic characteristics in stage-I non-small-cell lung carcinoma (NSCLC).

METHODS

The protein expression profiles of PTEN, p-Akt, p-mTOR, p-S6, and eIF4E were examined using immunohistochemical staining and tissue microarray method in 408 patients with stage-I NSCLC (250 adenocarcinomas [ADC] and 158 squamous cell carcinomas).

RESULTS

Retained PTEN expression (P<0.001), p-mTOR expression (P<0.001), and p-S6 expression (P=0.007) were associated with ADC histology. Expression of PTEN (P=0.001), p-Akt (P=0.005), p-mTOR (P=0.007), p-S6 (P<0.001) were correlated with lower pathologic T stage. PTEN loss was correlated with male gender and smoking history and p-mTOR expression was inversely correlated with these factors (P<0.001). Subgroup analysis of ADCs indicated that male gender, high pT stage, lymphovascular invasion, and PTEN loss were poor prognostic factors. Multivariate analysis revealed that the PTEN(-)/p-Akt(+)/p-mTOR(+) combination more effectively determined the prognosis of ADC (hazard ratio=2.2, P=0.004) than PTEN alone.

CONCLUSIONS

Activation of the mTOR pathway in early-stage ADCs suggests a significant role for the mTOR axis in early carcinogenesis. The combination of PTEN(-)/p-Akt(+)/p-mTOR(+) expression was correlated with poor overall survival in patients with stage-I lung ADC.

Regulatory mechanisms of betacellulin in CXCL8 production from lung cancer cells

Background

Betacellulin (BTC), a member of the epidermal growth factor (EGF) family, binds and activates ErbB1 and ErbB4 homodimers. BTC was expressed in tumors and involved in tumor growth progression. CXCL8 (interleukin-8) was involved in tumor cell proliferation via the transactivation of the epidermal growth factor receptor (EGFR).

Materials and methods

The present study was designed to investigate the possible interrelation between BTC and CXCL8 in human lung cancer cells (A549) and demonstrated the mechanisms of intracellular signals in the regulation of both functions. Bio-behaviors of A549 were assessed using Cell-IQ Alive Image Monitoring System.

Results

We found that BTC significantly increased the production of CXCL8 through the activation of the EGFR-PI3K/Akt-Erk signal pathway. BTC induced the resistance of human lung cancer cells to TNF-α/CHX-induced apoptosis. Treatments with PI3K inhibitors, Erk1/2 inhibitor, or Erlotinib significantly inhibited BTC-induced CXCL8 production and cell proliferation and movement.

Conclusion

Our data indicated that CXCL8 production from lung cancer cells could be initiated by an autocrine mechanism or external sources of BTC through the EGFR–PI3K–Akt–Erk pathway to the formation of inflammatory microenvironment. BTC may act as a potential target to monitor and improve the development of lung cancer inflammation.

Biliverdin's regulation of reactive oxygen species signalling leads to potent inhibition of proliferative and angiogenic pathways in head and neck cancer

BACKGROUND

In this study, we evaluate whether the use of biliverdin (BV), a natural non-toxic antioxidant product of haeme catabolism, can suppress head and neck squamous cell carcinoma (HNSCC) cell proliferation and improve the tumour survival both in vitro and in vivo. Furthermore, we investigate whether this therapeutic outcome relies on BV's potent antioxidant effect on reactive oxygen species (ROS)-mediated signalling.

METHODS

Two well-characterised HNSCC cell lines and a mouse model with human HNSCC were used for this study. In vitro, the effect of BV on ROS was assayed. Subsequently, critical regulatory proteins involved in growth, antiapoptotic, and angiogenic pathways were investigated by western blot analysis. In addition, the antiproliferative effect of BV was also evaluated using the clonogenic assay. Moreover, tumour growth inhibition was assessed using a mouse model with HNSCC.

RESULTS

Biliverdin treatment resulted in decreased ROS, leading to suppression of proliferation and angiogenesis pathways of HNSCC, significantly decreasing the expression and phosphorylation of oncogenic factors such as epidermal growth factor receptor (EGFR), phosphorylation of Akt, and expression of angiogenic marker and transcription factor, hypoxia-inducible factor1-α (HIF1-α). Furthermore, this downregulation of ROS by BV led to a significant suppression of tumour growth in vivo.

CONCLUSIONS

Our study demonstrates the efficacy of a novel therapeutic approach using BV as an antitumour agent against HNSCC through its effect on EGFR/Akt and HIF1-α/angiogenesis signal transduction pathways. Our findings indicate that BV's inhibitory effect on these tumorigenic pathways relies on its antioxidant effect, and may extend its therapeutic potential to other solid cancers.

Targeting AKT with the allosteric AKT inhibitor MK-2206 in non-small cell lung cancer cells with acquired resistance to cetuximab

The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in human cancers. Cetuximab is an anti-EGFR monoclonal antibody that has been approved for use in oncology. Despite clinical success the majority of patients do not respond to cetuximab and those who initially respond frequently acquire resistance. To understand how tumor cells acquire resistance to cetuximab we developed a model of resistance using the non-small cell lung cancer line NCI-H226. We found that cetuximab-resistant (Ctx (R) ) clones manifested strong activation of EGFR, PI3K/AKT and MAPK. To investigate the role of AKT signaling in cetuximab resistance we analyzed the activation of the AKT pathway effector molecules using a human AKT phospho-antibody array. Strong activation was observed in Ctx (R) clones for several key AKT substrates including c-jun, GSK3β, eIF4E, rpS6, IKKα, IRS-1 and Raf1. Inhibition of AKT signaling by siAKT1/2 or by the allosteric AKT inhibitor MK-2206 resulted in robust inhibition of cell proliferation in all Ctx (R) clones. Moreover, the combinational treatment of cetuximab and MK-2206 resulted in further decreases in proliferation than either drug alone. This combinatorial treatment resulted in decreased activity of both AKT and MAPK thus highlighting the importance of simultaneous pathway inhibition to maximally affect the growth of Ctx (R) cells. Collectively, our findings demonstrate that AKT activation is an important pathway in acquired resistance to cetuximab and suggests that combinatorial therapy directed at both the AKT and EGFR/MAPK pathways may be beneficial in this setting.

The PI3K/AKT pathway promotes gefitinib resistance in mutant KRAS lung adenocarcinoma by a deacetylase-dependent mechanism

To select the appropriate patients for treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), it is important to gain a better understanding of the intracellular pathways leading to EGFR-TKI resistance, which is a common problem in patients with lung cancer. We recently reported that mutant KRAS adenocarcinoma is resistant to gefitinib as a result of amphiregulin and insulin-like growth factor-1 receptor overexpression. This resistance leads to inhibition of Ku70 acetylation, thus enhancing the BAX/Ku70 interaction and preventing apoptosis. Here, we determined the intracellular pathways involved in gefitinib resistance in lung cancers and explored the impact of their inhibition. We analyzed the activation of the phosphatidyl inositol-3-kinase (PI3K)/AKT pathway and the mitogen-activated protein kinase/extracellular-signal regulated kinase (MAPK/ERK) pathway in lung tumors. The activation of AKT was associated with disease progression in tumors with wild-type EGFR from patients treated with gefitinib (phase II clinical trial IFCT0401). The administration of IGF1R-TKI or amphiregulin-directed shRNA decreased AKT signaling and restored gefitinib sensitivity in mutant KRAS cells. The combination of PI3K/AKT inhibition with gefitinib restored apoptosis via Ku70 downregulation and BAX release from Ku70. Deacetylase inhibitors, which decreased the BAX/Ku70 interaction, inhibited AKT signaling and induced gefitinib-dependent apoptosis. The PI3K/AKT pathway is thus a major pathway contributing to gefitinib resistance in lung tumors with KRAS mutation, through the regulation of the BAX/Ku70 interaction. This finding suggests that combined treatments could improve the outcomes for this subset of lung cancer patients, who have a poor prognosis.

Phosphorylated S6 as an immunohistochemical biomarker of vulvar intraepithelial neoplasia

As life expectancy lengthens, cases of non-viral-associated vulvar squamous cell carcinoma and its precursor lesion, so-called differentiated vulvar intraepithelial neoplasia (VIN), continue to increase in frequency. Differentiated VIN often is difficult to recognize and failure to detect it before invasion results in morbidity and mortality. Thus, identification of a reliable biomarker for this type of lesion would be of great clinical benefit. Our recent studies have identified activation (ser235/236 phosphorylation) of ribosomal protein S6 (p-S6) in basal epithelial cells as an event that precedes and accompanies laminin γ(2) overexpression in most preinvasive oral dysplasias. To test this as a potential biomarker of vulvar dysplasia, we immunostained seven differentiated VINs and nine papillomavirus-related 'classic' VINs, most of which were associated with carcinoma, for p-S6. All carcinomas, all differentiated VINs, and most classic VINs contained regions of p-S6 staining in the basal layer, whereas basal and parabasal cells of normal vulvar epithelium and hyperplastic and inflamed lesions lacking cellular atypia were p-S6 negative. Laminin γ(2) was expressed in a subset of VINs, always occurring within basal p-S6 positive regions, as we had found previously for oral dysplasias. Lichen sclerosus is considered a potential precursor of vulvar carcinoma. Two lichen sclerosus lesions of patients with a concurrent carcinoma and one of six lichen sclerosus lesions without atypia or known concurrent carcinoma were basal p-S6 positive. In summary, there is a distinct difference in p-S6 basal cell layer staining between benign and neoplastic vulvar squamous epithelium, with consistent staining of differentiated VIN and of some lichen sclerosus lesions. These results support further studies to assess the potential of p-S6 as a biomarker to identify vulvar lesions at risk of progressing to invasive cancer.

Combined inhibition of the EGFR and mTOR pathways in EGFR wild-type non-small cell lung cancer cell lines with different genetic backgrounds

The epidermal growth factor receptor (EGFR) signaling pathway is widely activated in non-small cell lung cancer (NSCLC). However, only a subset of patients with NSCLC is sensitive to EGFR tyrosine kinase inhibitors (TKIs), particularly those with activating EGFR mutations. The mammalian target of rapamycin (mTOR) is another key intracellular kinase that plays an important role in the onset and progression of many types of human cancers and has been proven to be linked with primary resistance to EGFR inhibitors. We performed this study to investigate the combined inhibitory effect of the mTOR inhibitor RAD001 and the EGFR-TKI gefitinib in three EGFR wild-type NSCLC cell lines: A549 (PIK3CA wild‑type), NCI-H460 (PIK3CA mutant) and NCI-H661 (PIK3CA wild-type). All cell lines demonstrate a poor response to gefitinib, but have a different genetic status for PIK3CA. We used MTT assays to measure cell proliferation. Flow cytometry was used to assess the effects on apoptosis and cell cycle arrest. Immunoblot analysis was used to evaluate the expression of downstream proteins. Treatment of RAD001 alone showed dose-dependent growth inhibition in all three cell lines. The combination of gefitinib and RAD001 resulted in synergistic growth inhibition in NCI-H460 cells, but only an additive inhibitory effect on A549 and NCI-H661 cells. Exposure to the combination of RAD001 and gefitinib led to a significant reduction in phosphorylated AKT levels in NCI-H460 cells; however, this was not noted in the other two cell lines. In conclusion, our data indicate that the dual inhibition of the EGFR/mTOR pathways may be a promising approach to treat EGFR wild-type NSCLC; however, this may be dependent on the PIK3CA mutation status.

Operant behavior to obtain palatable food modifies ERK activity in the brain reward circuit

Food palatability produces behavioral modifications that resemble those induced by drugs of abuse. Palatability-induced behavioral changes require both, the activation of the endogenous cannabinoid system, and changes in structural plasticity in neurons of the brain reward pathway. The ERK intracellular pathway is activated by CB1 receptors (CB1-R) and plays a crucial role in neuroplasticity. We investigated the activation of the ERK signaling cascade in the mesocorticolimbic system induced by operant training to obtain highly palatable isocaloric food and the involvement of the CB1-R in these responses. Using immunofluorescence techniques, we analyzed changes in ERK intracellular pathway activation in the mesocorticolimbic system of wild-type and CB1 knockout mice (CB1-/-) trained on an operant paradigm to obtain standard, highly caloric or highly palatable isocaloric food. Operant training for highly palatable isocaloric food, but not for standard or highly caloric food, produced a robust activation of the ERK signaling cascade in the same brain areas where this training modified structural plasticity. These changes induced by the operant training were absent in CB1-/-. We can conclude that the activation of the ERK pathway is associated to the neuroplasticity induced by operant training for highly palatable isocaloric food and might be involved in CB1-R mediated alterations in behavior and structural plasticity.

EGFR and HER2-Akt-mTOR signaling pathways are activated in subgroups of salivary gland carcinomas

Salivary gland carcinomas encompass a wide spectrum of histological entities. To identify candidate therapeutic targets and innovative treatment options for these carcinomas, we examined epidermal growth factor receptor (EGFR), phosphorylated EGFR (p-EGFR), HER2, and phosphorylated forms of Akt (p-Akt) and mammalian target of rapamycin (p-mTOR) in 47 salivary gland tumors using immunohistochemistry. EGFR overexpression was found in 51 % of the tumors (24/47); in particular, EGFR overexpression occurred in mucoepidermoid (seven out of seven) and salivary duct carcinomas (9/12). Although EGFR amplification was not detected by fluorescence in situ hybridization analysis, increased copy number due to polysomy of chromosome 7, which houses EGFR, was observed in 4 of the 24 tumors with EGFR overexpression; this polysomy occurred most frequently in salivary duct carcinomas (three out of nine). HER2 overexpression was observed in 21 % (10/47) of all tumors; in these 10 tumors, HER2 gene amplification was found in seven cases. p-Akt was found in 51 % (24/47) of all tumors, most frequently in mucoepidermoid carcinomas (six out of seven). p-mTOR was found in 57 % of the latter (four out of seven). Consequently, different signaling cascades were found activated: (1) an EGFR/HER2(-Akt)-mTOR-dependent axis, with gene gains of HER2 and/or EGFR, activated in salivary duct carcinoma and carcinoma ex pleomorphic adenoma; (2) an EGFR(-Akt)-mTOR-dependent pathway activated in mucoepidermoid carcinoma or acinic cell carcinoma, without HER2 or EGFR gene alterations; and (3) an Akt-dependent pathway without EGFR/HER2 activation in other types. These findings indicate that phosphoprotein mapping of components in the EGFR/HER2-Akt-mTOR pathways may be a useful guide to select appropriate targeting regimens.

Identification of mammalian target of rapamycin as a direct target of fenretinide both in vitro and in vivo

N-(4-hydroxyphenyl) retinamide (4HPR, fenretinide) is a synthetic retinoid that has been tested in clinical trials as a cancer therapeutic and chemopreventive agent. Although 4HPR has been shown to be cytotoxic to many kinds of cancer cells, the underlying molecular mechanisms are only partially understood. Until now, no direct cancer-related molecular target has been reported to be involved in the antitumor activities of 4HPR. Herein, we found that 4HPR inhibited mammalian target of rapamycin (mTOR) kinase activity by directly binding with mTOR, which suppressed the activities of both the mTORC1 and the mTORC2 complexes. The predicted binding mode of 4HPR with mTOR was based on a homology computer model, which showed that 4HPR could bind in the ATP-binding pocket of the mTOR protein through hydrogen bonds and hydrophobic interactions. In vitro studies also showed that 4HPR attenuated mTOR downstream signaling in a panel of non-small-cell lung cancer cells, resulting in growth inhibition. Moreover, knockdown of mTOR in cancer cells decreased their sensitivity to 4HPR. Results of an in vivo study demonstrated that i.p. injection of 4HPR in A549 lung tumor-bearing mice effectively suppressed cancer growth. The expression of mTOR downstream signaling molecules in tumor tissues was also decreased after 4HPR treatment. Taken together, our results are the first to identify mTOR as a direct antitumor target of 4HPR both in vitro and in vivo, providing a valuable rationale for guiding the clinical uses of 4HPR.

Mitochondrial DNA mutations in respiratory complex-I in never-smoker lung cancer patients contribute to lung cancer progression and associated with EGFR gene mutation

Mitochondrial DNA (mtDNA) mutations were reported in different cancers. However, the nature and role of mtDNA mutation in never-smoker lung cancer patients including patients with epidermal growth factor receptor (EGFR) and KRAS gene mutation are unknown. In the present study, we sequenced entire mitochondrial genome (16.5 kb) in matched normal and tumors obtained from 30 never-smoker and 30 current-smoker lung cancer patients, and determined the mtDNA content. All the patients' samples were sequenced for KRAS (exon 2) and EGFR (exon 19 and 21) gene mutation. The impact of forced overexpression of a respiratory complex-I gene mutation was evaluated in a lung cancer cell line. We observed significantly higher (P = 0.006) mtDNA mutation in the never-smokers compared to the current-smoker lung cancer patients. MtDNA mutation was significantly higher (P = 0.026) in the never-smoker Asian compared to the current-smoker Caucasian patients' population. MtDNA mutation was significantly (P = 0.007) associated with EGFR gene mutation in the never-smoker patients. We also observed a significant increase (P = 0.037) in mtDNA content among the never-smoker lung cancer patients. The majority of the coding mtDNA mutations targeted respiratory complex-I and forced overexpression of one of these mutations resulted in increased in vitro proliferation, invasion, and superoxide production in lung cancer cells. We observed a higher prevalence and new relationship between mtDNA alterations among never-smoker lung cancer patients and EGFR gene mutation. Moreover, a representative mutation produced strong growth effects after forced overexpression in lung cancer cells. Signature mtDNA mutations provide a basis to develop novel biomarkers and therapeutic strategies for never-smoker lung cancer patients.

Potential mechanism of interleukin-8 production from lung cancer cells: an involvement of EGF-EGFR-PI3K-Akt-Erk pathway

Tumor inflammatory microenvironment is considered to play the role in the sensitivity of tumor cells to therapies and prognosis of lung cancer patients. Interleukin-8 (IL-8) is one of critical chemo-attractants responsible for leukocyte recruitment, cancer proliferation, and angiogenesis. The present study aimed at investigating potential mechanism of IL-8 production from human non-small cell lung cancer (NSCLC) SPC-A1 cells. We initially found that EGF could directly stimulate IL-8 production, proliferation, and bio-behaviors of lung cancer cells through the activation of EGFR, PI3K, Akt, and Erk signal pathway. EGF-stimulated IL-8 production, phosphorylation of Akt and Erk, and cell proliferation and movement could be inhibited by EGFR inhibitor (Erlotinib), PI3K inhibitor (GDC-0941 BEZ-235 and SHBM1009), and ERK1/2 inhibitor (PD98059). Our data indicate that IL-8 production from lung cancer cells could be initiated by their own produced factors, leading to the recruitment of inflammatory cells in the cancer tissue, and the formation of inflammatory microenvironment. Thus, it seems that the signal pathway of EGFR-PI3K-Akt-Erk can be the potential target of therapies for inflammatory microenvironment in lung cancer.