EGFR mutations and clinical outcomes of chemotherapy for advanced non-small cell lung cancer: a meta-analysis

An Investigation of the Effect of the Traditional Naxi Herbal Formula Against Liver Cancer Through Network Pharmacology, Molecular Docking, and In Vitro Experiments

Background/Objectives: The formula Chong-Lou-Yao-Fang (CLYF) is an herbal medicinal formulation developed by the indigenous Naxi people for treating liver cancer. This study was to reveal the biological activity, potential targets, and molecular mechanisms of CLYF for cancer treatment. Methods: Network pharmacology, microarray data analysis, survival analysis, and molecular docking were employed to predict potential compounds, targets, and pathways for the treatment of liver cancer. In vitro experiments and Western blot validation were conducted to confirm these predictions. Results: 35 key compounds and 20 core targets were screened from CLYF, involving signaling pathways for PI3K-Akt, MAPK, hepatitis B and C, which were effective for liver cancer treatment. Microarray data analysis and survival analysis indicated that EGFR and TP53 serve as promising biomarkers for diagnosis and prognosis in liver cancer. Molecular docking revealed stable binding between EGFR, TP53, and AKT1 with active ingredients. Cell experiments confirmed that CLYF-A suppressed cell proliferation, induced apoptosis, and caused cell cycle arrest in HepG2 cells, which were associated with a loss of mitochondrial membrane potential. Compared to the control group, the relative protein expression levels of EGFR and AKT1 significantly decreased following treatment with CLYF-A, while TP53 levels increased significantly. Conclusions: Verification of the anticancer activity of CLYF and its potential mechanisms may have important implications for anticancer therapies. Our results may provide a scientific basis for the clinical use of CLYF for cancer treatment and have important implications for developing pharmaceutical preparations, which also need more pharmacological experiments, clinical experiments, and in vivo experiments.

Association between epidermal growth factor receptor gene mutation status and short‑term efficacy of first‑line platinum‑containing chemotherapy in advanced non‑small cell lung cancer

It remains undetermined whether there is an explicit association between the epidermal growth factor receptor (EGFR) gene mutation status and chemotherapy efficacy in non-small cell lung cancer (NSCLC) patients with advanced stages. Thus, the aim of the present retrospective study was to investigate the possible association between EGFR gene mutation status and the efficacy of first-line chemotherapy in patients with advanced NSCLC. In total, 52 patients who were diagnosed with NSCLC at Changzhou Tumor Hospital (Changzhou, China) from January 2015 to December 2018 were enrolled. All 52 patients received pemetrexed combined with platinum chemotherapy, for 21 days per cycle. After two cycles of treatment, the short-term clinical efficacy was assessed according to the Response Evaluation Criteria in Solid Tumours 1.1 guidelines. The objective response rate (ORR), disease control rate (DCR) and progression-free survival (PFS) rate were calculated at the end of the study (December 31, 2019). These patients also underwent second-generation gene sequencing before the potential association between mutations in the EGFR gene and chemotherapy efficacy was analyzed. In this group of patients, 25 cases (48.1%) were found to be harboring EGFR gene mutation, whilst 27 cases (51.9%) expressed wild-type EGFR. After receiving the first-line chemotherapy regimen, the ORR was determined to be 36.5%, the DCR was 71.2%, whereas the PFS period was 207 days. Following first-line chemotherapy, the DCR of patients with EGFR mutations (52%) was higher compared with those in patients harboring the wild-type EGFR (22%). By contrast, the PFS (260 days) of patients with EGFR mutations was longer compared with those in patients harboring wild-type EGFR (100 days). These differences were statistically significant (P<0.05). Multivariate analysis revealed that EGFR gene mutation was an independent predictor of PFS in patients with advanced NSCLC (P<0.05). To conclude, data from the present study suggest that EGFR gene mutation has independent predictive value for the efficacy of first-line chemotherapy in patients with advanced NSCLC.

Prognostic implication of EGFR gene mutations and histological classification in patients with resected stage I lung adenocarcinoma

Introduction

The prognostic value of epidermal growth factor receptor (EGFR) mutations and the correlation between EGFR mutations and the new International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histological classification remain controversial. The current study aimed to investigate the pure prognostic role of EGFR mutations in treatment-naïve patients with resected stage I lung adenocarcinoma.

Methods

We retrospectively reviewed 373 patients with stage I pulmonary non-small-cell lung cancer who underwent complete surgical resection between January 2010 and May 2014. The tumors were classified according to IASLC/ATS/ERS criteria. EGFR mutation status was determined by established methods.

Results

A total of 120 patients were included for analysis; 87 had tumors with EGFR mutations and 33 had wild-type tumors. More low- and intermediate-grade tumors had EGFR mutations, and nearly half of the high-grade tumors were wild-type (75.7% versus 46.2%, p = 0.041). Patients with low-grade tumors had significantly greater median disease-free survival (DFS) (76.8 versus 13 months, p < 0.0001) and better overall survival (OS) (median OS not reached, p = 0.0003) than those with intermediate- and high-grade tumors. Tumor recurrence was 41.4% and 30.3% in mutant and wild-type patients. The 5-years survival rate was 54% and 71.2%. Multivariate analysis revealed that the new histological classification and the pathologic stage were independent predictors of both DFS and OS. EGFR mutation status had no prognostic implications.

Conclusion

Low grade tumors according to IASLC/ATS/ERS histological classification and the pathologic stage IA tumors of resected stage I lung adenocarcinomas independently predict better DFS and OS. EGFR mutations were frequently seen in histologically low- and intermediate-grade tumors but not a prognostic factor.

Anaplastic lymphoma kinase gene rearrangement predicts better prognosis in NSCLC patients: A meta-analysis

OBJECTIVE

For non-small cell lung cancer (NSCLC), anaplastic lymphoma kinase (ALK) rearrangement and epidermal growth factor receptor (EGFR) mutations are predictive markers of the treatment benefit from selective tyrosine kinase inhibitors (TKI). However, their prognostic roles remained uncertain. Thus, we conducted this meta-analysis to evaluate the prognosis of ALK+ NSCLC patients in the treatment of surgery, chemotherapy, and/or EGFR-TKI.

MATERIALS AND METHODS

PubMed, Embase and Cochrane databases were thoroughly searched to identify relevant studies. Primary endpoints of this study included overall survival (OS), recurrence/progression free survival (RFS/PFS) and objective response rate (ORR). All statistical analyses were performed via REVIEW MANAGER (version 5.3).

RESULTS

In total, 15 studies involving 4981 NSCLC patients were included. This study demonstrated that smoking status profoundly influenced prognosis of ALK related NSCLC. In the general population with NSCLC, compared with ALK- arm, ALK+ arm obtained a significantly better prognosis (HR=0.81 for OS, 95% CI=0.72-0.91; 0.80 for RFS/PFS, 95% CI=0.70-0.90), even after further stratification analysis according to disease stage. However, in the non-smoking population with NSCLC, compared with ALK- arm, those in the ALK+ arm had a worse prognosis (HR=1.65 for OS, 95% CI=1.28-2.12; 1.23 for RFS/PFS, 95% CI=1.05-1.44). Furthermore, ALK+ patients experienced a significantly higher ORR in pemetrexed-based chemotherapy but not in EGFR-TKI.

CONCLUSIONS

Smoking status had a profound influence on the ALK-related prognosis of NSCLC. ALK rearrangement predicted a better prognosis in the general population with NSCLC, but a poor survival in the non-smoking population. Therefore, stratification according to smoking status is strongly recommended for future studies exploring ALK-related prognosis.

Advanced non small cell lung cancer: response to microwave ablation and EGFR Status

OBJECTIVES

To verify the association between EGFR status and clinical response to microwave ablation (MWA) and survival.

METHODS

NSCLC patients with known EGFR status and treated with MWA in combination with chemotherapy were retrospectively enrolled in the study.

RESULTS

A total of 61 patients were recruited. EGFR mutations were found in 28 patients (39.4 %), and were more common in women (67.7 %) and nonsmokers (74.1 %). Complete ablation was achieved in 69.7 % of patients with EGFR mutant tumours and in 82.1 % of patients with EGFR wild-type tumours (p = 0.216). The median progression-free survival (PFS) and overall survival (OS) were 8.3 months and 27.2 months in patients with an EGFR mutant tumour. The corresponding values were 5.4 months (p = 0.162) and 17.8 months (p = 0.209) in patients with an EGFR wild-type tumour. Patients with complete ablation had longer PFS (7.8 months vs. 4.2 months, p = 0.024) and OS (28.1 months vs. 12.6 months, p = 0.001) than those with incomplete ablation. Multivariate analyses also showed that response to MWA was an independent prognostic factor for OS, but EGFR status was not, and that neither response to MWA nor EGFR status was a prognostic factor for PFS.

CONCLUSIONS

The EGFR status was not related to response to MWA, and response to MWA was a predictor of survival.

KEY POINTS

• EGFR mutations were commonly seen in women and in nonsmokers • EGFR status had no correlation with the response to MWA, PFS and OS. • The response to MWA could predict PFS and OS.

EGFR kinase domain mutation positive lung cancers are sensitive to intrapleural perfusion with hyperthermic chemotherapy (IPHC) complete treatment

Lung cancer is the global leading cause of cancer-related deaths. A significant portion of lung cancer patients harbor kinase domain mutations in the epidermal growth factor receptor (EGFR). While EGFR tyrosine kinase inhibitors (TKI) effectively shrink tumors harboring mutant EGFR, clinical efficacy is limited by the development of TKI resistance. Effective alternatives are desperately needed in clinic for treating EGFR kinase domain mutation positive lung cancer. In our clinic in treating M1a lung cancer patients through intrapleural perfusion with hyperthermic chemotherapy (IPHC) followed by cycles of systemic chemotherapy (we termed this procedure IPHC complete treatment, IPHC-CT), we found dramatic tumor shrinkage in mutant EGFR-positive patients. We further confirmed the sensitivity of EGFR mutation-positive lung cancer cell lines derived from patients to HC (hyperthermic chemotherapy) treatment. We found that hyperthermia promoted accumulation of cisplatin in lung cancer cells. Hyperthermia and cisplatin synergistically downregulated the EGFR protein level, leading to quenching of signal from EGFR and induction of apoptosis. Our work therefore showed IPHC-CT is an effective treatment for EGFR kinase domain mutation positive lung cancer patients.

Impact of active smoking on survival of patients with metastatic lung adenocarcinoma harboring an epidermal growth factor receptor (EGFR) mutation

Lung cancer in smokers and non-smokers demonstrates distinct genetic profiles, and cigarette smoking affects epidermal growth factor receptor (EGFR) function and causes secondary EGFR tyrosine kinase resistance. We evaluated the effect of active smoking in patients with metastatic lung adenocarcinoma. A total of 132 metastatic lung adenocarcinoma patients, diagnosed between 2008 and 2013, with known EGFR mutation status, were evaluated retrospectively. Among these patients, 40 had an activating EGFR mutation. Patients who continued smoking during the treatment were defined as active smokers. Former smokers and never smokers were together defined as non-smokers. The outcomes of the treatment in relation to the EGFR mutation and smoking status were evaluated. The median follow-up time was 10.5 months. The overall response rate for the first-line therapy was significantly higher among the EGFR-mutant patients (p = 0.01), however, smoking status had no impact on the response rate (p = 0.1). The EGFR-mutant active smokers progressed earlier than the non-smokers (p < 0.01). The overall survival (OS) of the non-smokers and patients treated with erlotinib was significantly longer (p = 0.02 and p = 0.01, respectively). Smoking status did not affect the OS in EGFR wild type tumors (p = 0.49) but EGFR-mutant non-smokers had a longer OS than the active smokers (p = 0.01).The active smokers treated with erlotinib had poorer survival than the non-smokers (p = 0.03). Multivariate analysis of EGFR-mutant patients showed that erlotinib treatment at any line and non-smoking were independent prognostic factors for the OS (p = 0.04 and p = 0.01, respectively). Smoking during treatment is a negative prognostic factor in metastatic lung adenocarcinoma with an EGFR mutation.

A decade of EGFR inhibition in EGFR-mutated non small cell lung cancer (NSCLC): Old successes and future perspectives

The discovery of Epidermal Growth Factor Receptor (EGFR) mutations in Non Small Cell Lung Cancer (NSCLC) launched the era of personalized medicine in advanced NSCLC, leading to a dramatic shift in the therapeutic landscape of this disease. After ten years from the individuation of activating mutations in the tyrosine kinase domain of the EGFR in NSCLC patients responding to the EGFR tyrosine kinase inhibitor (TKI) Gefitinib, several progresses have been done and first line treatment with EGFR TKIs is a firmly established option in advanced EGFR-mutated NSCLC patients. During the last decade, different EGFR TKIs have been developed and three inhibitors have been approved so far in these selected patients. However, despite great breakthroughs have been made, treatment of these molecularly selected patients poses novel therapeutic challenges, such as emerging of acquired resistance, brain metastases development or the need to translate these treatments in earlier clinical settings, such as adjuvant therapy.

The aim of this paper is to provide a comprehensive review of the major progresses reported so far in the EGFR inhibition in this molecularly-selected subgroup of NSCLC patients, from the early successes with first generation EGFR TKIs, Erlotinib and Gefitinib, to the novel irreversible and mutant-selective inhibitors and ultimately the emerging challenges that we, in the next future, are called to deal with.

Former smokers with non-small-cell lung cancers: a comprehensive investigation of clinicopathologic characteristics, oncogenic drivers, and prognosis

The aim of this present investigation was to evaluate the clinicopathologic characteristics, oncogenic drivers, and prognosis of former smokers with non‐small‐cell lung cancer (NSCLC), and to compare them with those of the current and never smokers. This investigation was a single‐institution retrospective study of 2289 NSCLC patients, who were classified as former, current, or never smokers. A collection was made of the clinicopathological characteristics, spectra of well‐identified driver genes and survival rates. The survival rates were compared using log‐rank test, and independent prognostic factors, identified using Cox regression analysis. Of 2289 NSCLC patients, 257 (11.2%) were former smokers; 868 (37.9%), current smokers; and 1164 (50.9%), never smokers. Compared with the current, the former were characterized by older age at diagnosis (64.3y vs. 59.9y; P < 0.001), earlier TNM stage (stage I, 47.9% vs. 39.5%; P = 0.017), fewer solid predominance in adenocarcinomas (16.2% vs. 29.5%; P = 0.005), and more EGFR mutation (33.2% vs. 20.7%; P < 0.001) but less KRAS mutation (6.7% vs. 11.9%, P = 0.041). No statistically significant survival differences were observed between the former and current. However, the light former smokers presented favorable overall survival when compared with the light current and heavy former or current (the light former vs. the heavy former, P = 0.028; the light former vs. the light current, P = 0.048; and the light former vs. the heavy current, P = 0.048). Our findings suggest that the former smokers with NSCLCs can have distinctive clinicopathologic characteristics, oncogenic drivers, and prognosis, and they, especially the light former, can benefit from smoking cessation.

[Association between the epidermal growth receptor status and the efficacy of first-line chemotherapy in patients with advanced non-small cell lung cancer]

背景与目的

表皮生长因子受体（epidermal growth factor receptor, EGFR）基因状态是表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor tyrosine kinase inhibitor, EGFR-TKI）疗效的预测因素，但其对化疗疗效的预测作用尚不明确。本研究旨在探讨对晚期非小细胞肺癌（non-small cell lung cancer, NSCLC）患者一线化疗疗效的预测意义。

方法

收集首都医科大学附属北京胸科医院自2006年1月10日-2013年12月20日经组织病理学证实的181例Ⅲb期/Ⅳ期的NSCLC患者。分析EGFR基因状态、临床特征与化疗疗效及无疾病进展生存期（progression-free survival, PFS）之间的关系。

结果

181例患者均进行了EGFR基因检测，EGFR突变患者75例（41.4%），野生型为106例（58.6%）。全部患者均接受一线化疗，客观缓解率（objective response rate, ORR）为26.0%，疾病控制率（disease control rate, DCR）为70.2%。EGFR突变患者的DCR显著高于EGFR野生型患者高（84.0% vs 60.4%, P=0.001）。亚组分析显示，19外显子缺失突变患者化疗的ORR、DCR均高于EGFR野生型患者（P值分别为0.049，0.002）。21外显子L858R突变患者的DCR高于EGFR野生型患者（P=0.010）。全部患者中，168例患者可评价PFS，中位PFS为4.3个月，其中腺癌患者PFS较鳞癌患者延长（4.7个月 vs 3.0个月，P=0.036）；突变患者PFS长于野生型患者（6.3个月 vs 3.0个月，P=0.002）；体力状况评分（performance status, PS）0-1分组患者PFS较评分为2分延长（4.4个月 vs 0.7个月，P=0.016）。Cox多因素分析显示，EGFR突变是影响PFS的独立因素（HR=0.654, 95%CI: 0.470-0.909, P=0.012）。

结论

EGFR突变是晚期NSCLC患者一线化疗PFS的预测因素。

The Metastasis Suppressor, N-MYC Downstream-regulated Gene-1 (NDRG1), Down-regulates the ErbB Family of Receptors to Inhibit Downstream Oncogenic Signaling Pathways

N-MYC downstream-regulated gene-1 (NDRG1) is a potent growth and metastasis suppressor that acts through its inhibitory effects on a wide variety of cellular signaling pathways, including the TGF-β pathway, protein kinase B (AKT)/PI3K pathway, RAS, etc. To investigate the hypothesis that its multiple effects could be regulated by a common upstream effector, the role of NDRG1 on the epidermal growth factor receptor (EGFR) and other members of the ErbB family, namely human epidermal growth factor receptor 2 (HER2) and human epidermal growth factor receptor 3 (HER3), was examined. We demonstrate that NDRG1 markedly decreased the expression and activation of EGFR, HER2, and HER3 in response to the epidermal growth factor (EGF) ligand, while also inhibiting formation of the EGFR/HER2 and HER2/HER3 heterodimers. In addition, NDRG1 also decreased activation of the downstream MAPKK in response to EGF. Moreover, novel anti-tumor agents of the di-2-pyridylketone class of thiosemicarbazones, namely di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone and di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone, which markedly up-regulate NDRG1, were found to inhibit EGFR, HER2, and HER3 expression and phosphorylation in cancer cells. However, the mechanism involved appeared dependent on NDRG1 for di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone, but was independent of this metastasis suppressor for di-2-pyridylketone 4-cyclohexyl-4-methyl-3-thiosemicarbazone. This observation demonstrates that small structural changes in thiosemicarbazones result in marked alterations in molecular targeting. Collectively, these results reveal a mechanism for the extensive downstream effects on cellular signaling attributed to NDRG1. Furthermore, this study identifies a novel approach for the treatment of tumors resistant to traditional EGFR inhibitors.

PCR-sequencing is a complementary method to amplification refractory mutation system for EGFR gene mutation analysis in FFPE samples

Amplification Refractory Mutation System (ARMS) is the most popular technology for EGFR gene mutation analysis in China. Cutoff Ct or ΔCt values were used to differentiate low mutation abundance cases from no mutation cases. In this study, all of 359 NSCLC samples were tested by ARMS. Seventeen samples with larger Ct or ΔCt than cutoff values were retested by PCR-sequencing. TKI treatment responses were monitored on the cases with ARMS negative and PCR-sequencing positive results. One exon 18 G719X case, 67 exon 19 deletion cases, 2 exon 20 insertion cases, 1 exon 20 T790M case, 60 exon 21 L858R cases, 5 exon 21 L861Q cases and 201 wild type cases were identified by ARMS. Another 22 cases were evaluated as wild type but had later amplification fluorescent curves. Seventeen out of these 22 cases were retested by PCR-sequencing. It turns out that 3 out of 3 cases with exon 19 deletion later amplifications, 2 out of 2 cases with L858R later amplifications and 4 out of 12 cases with T790M later amplifications were identified as mutation positive. Two cases with exon 19 deletion and L858R respectively were treated by TKI and got responses. Our study indicated that PCR-sequencing might be a complementary way to confirm ARMS results with later amplifications.

Navigating into the binding pockets of the HER family protein kinases: discovery of novel EGFR inhibitor as antitumor agent

The epidermal growth factor receptor (EGFR) family has been validated as a successful antitumor drug target for decades. Known EGFR inhibitors were exposed to distinct drug resistance against the various EGFR mutants within non-small-cell lung cancer (NSCLC), particularly the T790M mutation. Although so far a number of studies have been reported on the development of third-generation EGFR inhibitors for overcoming the resistance issue, the design procedure largely depends on the intuition of medicinal chemists. Here we retrospectively make a detailed analysis of the 42 EGFR family protein crystal complexes deposited in the Protein Data Bank (PDB). Based on the analysis of inhibitor binding modes in the kinase catalytic cleft, we identified a potent EGFR inhibitor (compound A-10) against drug-resistant EGFR through fragment-based drug design. This compound showed at least 30-fold more potency against EGFR T790M than the two control molecules erlotinib and gefitinib in vitro. Moreover, it could exhibit potent HER2 inhibitory activities as well as tumor growth inhibitory activity. Molecular docking studies revealed a structural basis for the increased potency and mutant selectivity of this compound. Compound A-10 may be selected as a promising candidate in further preclinical studies. In addition, our findings could provide a powerful strategy to identify novel selective kinase inhibitors on the basis of detailed kinase–ligand interaction space in the PDB.

MiR-205 and miR-218 expression is associated with carboplatin chemoresistance and regulation of apoptosis via Mcl-1 and Survivin in lung cancer cells

Lung cancer chemoresistance is the most frequent barrier in lung cancer therapy. Recent studies have indicated that microRNAs play a significant role in this mechanism and can function as either tumor suppressor or tumor promoters. However the effect of miRNA in lung cancer chemoresistance is poorly understood. Therefore, in the present study we investigated the role of two distinct miR members, the miR-205 and the tumor suppressor miR-218 in the proliferation, invasion and induction of apoptosis in lung cancer cells after carboplatin treatment. The results showed that miR-205 overexpression in A549 and H1975 lung cancer cells is concurrent with the down regulation of miR-218 and in linked with carboplatin sensitivity and chemoresistance. Interestingly, ectopic miR-218 overexpression reduced cell proliferation, invasion and migration of lung cancer cells, whereas miR-205 rescued the suppressive effect of miR-218 by altering the expression levels of the pro-apoptotic proteins PARP, Caspase 3, Bax and upregulating the anti-apoptotic markers Mcl-1 and Survivin. Taken together our findings imply that the miRNAs miR-205 and miR-218 play a key role in the development of lung cancer acquired chemoresistance and the tumor suppressor role of miR-218 in inhibiting lung cancer cell tumorigenesis and overcoming platinum chemoresistance is significant for future cancer therapeutic approaches.

Molecular histology of lung cancer: from targets to treatments

Lung cancer is the leading cause of cancer-related death worldwide with a 5-year survival rate of less than 15%, despite significant advances in both diagnostic and therapeutic approaches. Combined genomic and transcriptomic sequencing studies have identified numerous genetic driver mutations that are responsible for the development of lung cancer. In addition, molecular profiling studies identify gene products and their mutations which predict tumour responses to targeted therapies such as protein tyrosine kinase inhibitors and also can offer explanation for drug resistance mechanisms. The profiling of circulating micro-RNAs has also provided an ability to discriminate patients in terms of prognosis/diagnosis and high-throughput DNA sequencing strategies are beginning to elucidate cell signalling pathway mutations associated with oncogenesis, including potential stem cell associated pathways, offering the promise that future therapies may target this sub-population, preventing disease relapse post treatment and improving patient survival. This review provides an assessment of molecular profiling within lung cancer concerning molecular mechanisms, treatment options and disease-progression. Current areas of development within lung cancer profiling are discussed (i.e. profiling of circulating tumour cells) and future challenges for lung cancer treatment addressed such as detection of micro-metastases and cancer stem cells.

RNA-Seq and Network Analysis Revealed Interacting Pathways in TGF-β-Treated Lung Cancer Cell Lines

Whole transcriptome shotgun sequencing (RNA-Seq) is a useful tool for analyzing the transcriptome of a biological sample. With appropriate statistical and bioinformatic processing, this platform is capable of identifying significant differences in gene expression within the transcriptome and permits pathway and network analyses to determine how these genes interact biologically. In this study, we examined gene expression in two lung adenocarcinoma cell lines (H358 and A459) that were treated with transforming growth factor-β (TGF-β) as a model for induction of the epithelial-to-mesenchymal transition (EMT), commonly associated with disease progression. We performed this study in order to illustrate a workflow for identifying interesting genes and processes that are regulated early in EMT and to determine their gene pathway/network relationships and regulation. With this, we identified 137 upregulated and 32 downregulated genes common to both cell lines after TGF-β treatment that represent components of multiple canonical pathways and biological networks associated with the induction of EMT. These findings were also verified against reposited Affymetrix U133a expression profiles from multiple trials examining metastatic progression in patient cohorts (n = 731 total) to further establish the clinical relevance and translational significance of the model system. Together, these findings help validate the relevance of the TGF-β model for the study of EMT and provide new insights into early events in EMT.

Chronic nicotine exposure mediates resistance to EGFR-TKI in EGFR-mutated lung cancer via an EGFR signal

BACKGROUND

Some of patients with non-small cell lung cancer (NSCLC) harboring somatic activating mutations of the epidermal growth factor receptor gene (EGFR mutations) show poor responses to EGFR-tyrosine kinase inhibitors (EGFR-TKIs) treatment. Cigarette smoking is the strongest documented risk factor for the development of lung cancer. Nicotine, while not carcinogenic by itself, has been shown to induce proliferation, angiogenesis, and the epithelial-mesenchymal transition; these effects might be associated with EGFR-TKI resistance.

MATERIALS AND METHODS

PC-9 and 11_18 cell lines (EGFR-mutated NSCLC cell lines) were cultured with 1μM nicotine for 3 months and were designated as PC-9/N and 11_18/N cell lines, respectively. The sensitivities of these cell lines to EGFR-TKI were then tested in vitro. Moreover, the association between the smoking status and the progression-free survival (PFS) period was investigated in patients with EGFR-mutated NSCLC who were treated with gefitinib.

RESULTS

The PC-9/N and 11_18/N cell lines were resistant to EGFR-TKI, compared with controls. The phosphorylation of EGFR in these cell lines was reduced by EGFR-TKI to a smaller extent than that observed in controls, and a higher concentration of EGFR-TKI was capable of further decreasing the phosphorylation. Clinically, smoking history was an independent predictor of a poor PFS period on gefitinib treatment.

CONCLUSIONS

Chronic nicotine exposure because of cigarette smoking mediates resistance to EGFR-TKI via an EGFR signal. Smoking cessation is of great importance, while resistance may be overcome through the administration of high-dose EGFR-TKI.

EGFR and K-Ras mutations in women with lung adenocarcinoma: implications for treatment strategy definition

Background

We aimed at investigating the outcomes of female patients with stage IIIB-IV adenocarcinoma of the lung according to EGFR and K-Ras mutational status.

Methods

One hundred and three consecutive female patients genotyped at a single Italian Institution were analyzed. Patients were planned to receive first-line platinum-based chemotherapy (CT) and a salvage treatment with anti-EGFR tyrosine-kinase inhibitors (TKIs) was proposed irrespective of tumor mutational status. EGFR (exons 18–21) and K-Ras (exon 2, codons 12–13) mutations were evaluated by real-time PCR and pyrosequencing. The association of mutational status with clinical variables and treatment benefit was investigated by chi-square test and log-rank test.

Results

EGFR and K-Ras mutations were found in 31 (30%) and 13 (15%) cases, respectively. Sixty-six patients received platinum CT: no correlation was observed between EGFR or K-Ras mutational status and response rate (RR) (p > 0.05). However, patients treated with first-line CT harboring EGFR activating mutations experienced a significantly reduced progression-free survival (PFS) in comparison with wild-type ones (4.4 vs. 6.4 months, respectively; HR 0.597, 95% CI 0.287-0.975; p = 0.048). Thirty-nine patients received salvage treatment with erlotinib: EGFR activating mutations were significantly correlated with RR (60% vs. 12.5%; p = 0.004) and PFS (11.4 vs. 4.5 months; HR 0.491, 95% CI 0.216-0.936; p = 0.044). Responses to erlotinib were not reported among women with K-Ras mutant tumors, while 50% of those with wild-type K-Ras achieved an objective remission (p = 0.296). Median PFS (3.5 vs. 8.8 months; HR 0.284, 95% CI 0.015-0.510; p = 0.010) and OS (3.9 vs. 19.8 months; HR 0.158, 95% CI 0.001-0.075; p < 0.001) were significantly shorter among K-Ras mutant patients treated with TKI.

Conclusions

In our population of Caucasian women with advanced lung adenocarcinoma we observed that the presence of EGFR activating mutations correlates with a significant reduction in the benefit from first-line platinum-based CT, emphasizing the importance of an upfront use of anti-EGFR TKIs in this patient subset. K-Ras mutations seem to correlate with a detrimental effect from anti-EGFR TKI, but this finding deserves further investigation.