Gerald Schmid-Bindert

MicroRNA-214 Regulates the Acquired Resistance to Gefitinib via the PTEN/AKT Pathway in EGFR-mutant Cell Lines

Patients with non-small cell lung cancer (NSCLC) who have activating epidermal growth factor receptor (EGFR) mutations derive clinical benefit from treatment with EGFR-tyrosine kinase inhibitors ((EGFR-TKIs)- namely gefitinib and erlotinib. However, these patients eventually develop resistance to EGFR-TKIs. Despite the fact that this acquired resistance may be the result of a secondary mutation in the EGFR gene, such as T790M or amplification of the MET proto-oncogene, there are other mechanisms which need to be explored. MicroRNAs (miRs) are a class of small non-coding RNAs that play pivotal roles in tumorigenesis, tumor progression and chemo-resistance. In this study, we firstly successfully established a gefitinib resistant cell line-HCC827/GR, by exposing normal HCC827 cells (an NSCLC cell line with a 746E-750A in-frame deletion of EGFR gene) to increasing concentrations of gefitinib. Then, we found that miR-214 was significantly up-regulated in HCC827/ GR. We also showed that miR-214 and PTEN were inversely expressed in HCC827/GR. Knockdown of miR-214 altered the expression of PTEN and p-AKT and re-sensitized HCC827/GR to gefitinib. Taken together, miR-214 may regulate the acquired resistance to gefitinib in HCC827 via PTEN/AKT signaling pathway. Suppression of miR-214 may thus reverse the acquired resistance to EGFR-TKIs therapy.

Blocking the PI3K/AKT and MEK/ERK signaling pathways can overcome Gefitinib-resistance in non-small cell lung cancer cell lines

PURPOSE To investigate the effects of gefitinib (EGFR-TKI), LY294002 (PI3K inhibitor) and U0126 (MEK inhibitor) on proliferation and apoptosis in five non-small cell lung cancer (NSCLC) cell lines (PC9, PC9/AB2, H1975, H1299 and A549). METHODS The inhibitory rates of cells were tested by MTT and apoptosis was detected through flow cytometry when treated with gefitinib, LY294002 and U0126. RESULTS The sensitivity to gefitinib was different in different cell lines, which was associated with EGFR mutation type. The cells with EGFR mutation were more sensitive than those with EGFR wild-type, except PC9/AB2 cells. LY294002 and U0126 can inhibit cell proliferation and promote apoptosis in all five cell lines. The sensitivity to gefitinib was restored partially in the resistant cell lines by combining gefitinib with LY294002 or U0126. The effects on cell proliferation and apoptosis were stronger in cells with EGFR mutation when PI3K/AKT pathway was blocked, however, for cells with EGFR wild-type, the effects were stronger when the MEK pathway was blocked. When the PI3K and MEK pathways were blocked together, proliferation inhibition and apoptosis level in NSCLC cells was similar to that in cells treated with EGFR TKI. There were some differences according to EGFR mutation type, suggesting that EGFR mutations may result in alterations of downstream signaling pathways. CONCLUSION The sensitivity of gefitinib resistant cell lines can be restored partially when the two downstream signaling pathways are blocked. However, these cells were still drug resistant, suggesting that the activation of PI3K and MEK pathways is not the only mechanism of EGFR-resistance.

Diffusion and perfusion MRI of the lung and mediastinum.

With ongoing technical improvements such as multichannel MRI, systems with powerful gradients as well as the development of innovative pulse sequence techniques implementing parallel imaging, MRI has now entered the stage of a radiation-free alternative to computed tomography (CT) for chest imaging in clinical practice. Whereas in the past MRI of the lung was focused on morphological aspects, current MRI techniques also enable functional imaging of the lung allowing for a comprehensive assessment of lung disease in a single MRI exam. Perfusion imaging can be used for the visualization of regional pulmonary perfusion in patients with different lung diseases such as lung cancer, chronic obstructive lung disease, pulmonary embolism or for the prediction of postoperative lung function in lung cancer patients. Over the past years diffusion-weighted MR imaging (DW-MRI) of the thorax has become feasible with a significant reduction of the acquisition time, thus minimizing artifacts from respiratory and cardiac motion. In chest imaging, DW-MRI has been mainly suggested for the characterization of lung cancer, lymph nodes and pulmonary metastases. In this review article recent MR perfusion and diffusion techniques of the lung and mediastinum as well as their clinical applications are reviewed.

Targeted Therapy for Patients with BRAF-Mutant Lung Cancer Results from the European EURAF Cohort

Introduction: Approximately 2% of lung adenocarcinomas have BRAF (v-Raf murine sarcoma viral oncogene homolog B) mutations, including V600E and other types. Vemurafenib, dabrafenib, and sorafenib as BRAF inhibitors are currently tested in clinical trials, but access for patients is limited. The aim of this study was to document the clinical course of patients treated outside of clinical trials. Methods: We conducted a retrospective multicenter cohort study in Europe of patients with advanced BRAF-mutant lung cancer treated with known BRAF inhibitors. Data were anonymized and centrally assessed for age, gender, smoking, histology, stage, local molecular diagnostic results, systemic therapies, and survival. Best response was assessed locally by RECIST1.1. Results: We documented 35 patients treated in 17 centers with vemurafenib, dabrafenib, or sorafenib. Median age was 63 years (range 42–85); gender was balanced; 14 (40%) were never smokers; all (100%) had adenocarcinoma; 29 (83%) had V600E; 6 (17%) had other mutations; one of them had a concomitant KRAS mutation. Thirty (86%) patients had chemotherapy in the first line. Overall survival with first-line therapy was 25.3 months for V600E and 11.8 months for non-V600E. Thirty-one patients received one BRAF inhibitor, and four received a second inhibitor. Overall response rate with BRAF therapy was 53%, and disease control rate was 85%. Median progression-free survival with BRAF therapy was 5.0 months, and overall survival was 10.8 months. Conclusions: These results confirm the activity of targeted therapy in patients with BRAF-mutant lung adenocarcinoma. Further trials are warranted to study combination therapies and drug resistance mechanisms.

ROS1 fusions in Chinese patients with non-small-cell lung cancer

BACKGROUND To determine the prevalence and clinicopathological features of ROS1 fusions in Chinese patients with non-small-cell lung cancer (NSCLC). METHODS Formalin-fixed and paraffin-embedded (FFPE) tissue sections from 392 patients with NSCLC were screened for ROS1 fusions by multiplex RT-PCR and all ROS1 fusions were validated by direct sequencing. The relationship between ROS1 fusions and clinicopathological features and the prognostic effect of the ROS1 fusion status on survival were analyzed. RESULTS In this study, 8 of 392 (2.0%) evaluable samples were found to harbor ROS1 fusions. Of the ROS1-positive patients, seven presented with adenocarcinoma, and one with adenosquamous carcinoma. The ratio of female to male and never smoker to smokers in a ROS1 fusion-positive group was 5:3. There was no statistically significant difference in age, sex, smoking history, histological type and pathological stage between ROS1 fusion-positive and ROS1 fusion-negative patients. ROS1 fusion-negative patients had a significantly longer survival when compared with ROS1 fusion-positive patients (P = 0.041). Lower pathological stage, younger age and ROS1 fusion-negative status were significantly associated with better prognosis on multivariate analysis. CONCLUSIONS ROS1 fusions occurred in ∼2.0% of Chinese patients with NSCLC and had no specific clinicopathological feature. ROS1 fusion-negative patients may have a better survival than ROS1 fusion-positive patients.BACKGROUND To determine the prevalence and clinicopathological features of ROS1 fusions in Chinese patients with non-small-cell lung cancer (NSCLC). METHODS Formalin-fixed and paraffin-embedded (FFPE) tissue sections from 392 patients with NSCLC were screened for ROS1 fusions by multiplex RT-PCR and all ROS1 fusions were validated by direct sequencing. The relationship between ROS1 fusions and clinicopathological features and the prognostic effect of the ROS1 fusion status on survival were analyzed. RESULTS In this study, 8 of 392 (2.0%) evaluable samples were found to harbor ROS1 fusions. Of the ROS1-positive patients, seven presented with adenocarcinoma, and one with adenosquamous carcinoma. The ratio of female to male and never smoker to smokers in a ROS1 fusion-positive group was 5:3. There was no statistically significant difference in age, sex, smoking history, histological type and pathological stage between ROS1 fusion-positive and ROS1 fusion-negative patients. ROS1 fusion-negative patients had a significantly longer survival when compared with ROS1 fusion-positive patients (P = 0.041). Lower pathological stage, younger age and ROS1 fusion-negative status were significantly associated with better prognosis on multivariate analysis. CONCLUSIONS ROS1 fusions occurred in ∼2.0% of Chinese patients with NSCLC and had no specific clinicopathological feature. ROS1 fusion-negative patients may have a better survival than ROS1 fusion-positive patients.

High Discrepancy of Driver Mutations in Patients with NSCLC and Synchronous Multiple Lung Ground-Glass Nodules

Background: The aim of this study was to investigate the discordance rates of eight known driver mutations among multiple matched intrapulmonary ground-glass nodules (GGNs) in non–small-cell lung cancer (NSCLC) patients. Methods: Tumors from 35 patients with multiple lesions resected, including confirmed NSCLC and at least one GGN, were analyzed for mutations in EGFR, KRAS, HER2, BRAF, and PIK3CA together with fusions in ALK, ROS1, and RET. Results: From 35 patients, a total of 72 lesions (60 were GGNs) were analyzed. These included nine adenocarcinoma in situ, nine minimal invasive adenocarcinoma, and 54 invasive adenocarcinoma. Among them, 33 tumor lesions (45.8 %) were found harboring EGFR mutations: 13 tumors with exon 19 deletion, 18 with L858R on exon 21, and two with both exon 19 del and L858R mutation. There were 5 tumors (6.9 %) harboring EML4-ALK fusion, four HER2 mutations (5.6%), three KRAS mutations (4.2%), one ROS1 fusion and one BRAF mutation. When we used the matched tumors to determine the intertumor discrepancy, only six out of 30 patients harbored identical mutations. The discordance rate of driver mutations was 80% (24 of 30) in those patients harboring at least one of the detected driver mutations. The median disease-free survival was 41.2 months (95% confidence interval: 35.8–52.6 months) and the median overall survival was “still not reached” in this cohort. Conclusions: We found a high discrepancy of driver mutations among NSCLC patients with GGNs and a favorable prognosis after multiple lesions resection, which support surgical resection in this situation as a reasonable approach.

Erlotinib in the treatment of advanced non-small cell lung cancer: an update for clinicians

Inhibition of epidermal growth factor receptor (EGFR) has become an important target in the treatment of advanced non-small cell lung cancer (NSCLC). Erlotinib and gefitinib, two small molecular agents that target the tyrosine kinase domain of the EGFR, were approved in many countries for the treatment of locally advanced or metastatic NSCLC as a second- or third-line regimen. Since then, randomized trials have evaluated the role of these two targeted agents alone or combined with chemotherapy in maintenance and first-line settings. This review summarizes the results of recent clinical trials with these tyrosine kinase inhibitors, with a focus on erlotinib, as first-line treatment towards a form of personalized medicine aimed at improving clinical outcome in advanced NSCLC.

Association of EGFR mutation or ALK rearrangement with expression of DNA repair and synthesis genes in never-smoker women with pulmonary adenocarcinoma

Epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement may predict the outcome of targeted drug therapy and also are associated with the efficacy of chemotherapy in patients with nonsmall cell lung cancer (NSCLC). The authors of this report investigated the relation of EGFR mutation or ALK rearrangement status and the expression of DNA repair or synthesis genes, including excision repair cross‐complementing 1 (ERCC1), ribonucleotide reductase subunit M1 (RRM1), thymidylate synthetase (TS), and breast cancer‐early onset (BRCA1), as a potential explanation for these observations.

T790M mutation is associated with better efficacy of treatment beyond progression with EGFR-TKI in advanced NSCLC patients

BACKGROUND AND PURPOSE Continuous EGFR-TKI treatment beyond progression has shown promising benefit for some patients with acquired resistance to EGFR-TKIs. The aim of this study was to investigate the association of secondary T790M mutation at the time of progression with the efficacy of EGFR-TKI treatment beyond progression. METHODS From March 2011 to March 2013, patients with advanced NSCLC who developed acquired resistance to EGFR-TKI and where a re-biopsy was performed at Tongji University Cancer Institute were included into this study. Scorpion ARMS was used to detect EGFR mutation status. RESULTS A total of 54 patients were enrolled in this study with a median progression-free survival time (PFS1) of 10.9 months according to RECIST criteria. In all, 53.7% (29/54) had T790M mutation after the failure of EGFR-TKIs; PFS1 was not statistically significantly different between patients with T790M mutation and without (13.0 vs. 10.5 months, p = 0.894). In all, 41 patients received TKI treatment beyond progression, including 22 with local progression to receive additional local therapy and 19 with gradual progression to receive additional chemotherapy. The median progression-free survival time (PFS2) of patients who received EGFR-TKI beyond progression treatment was 3.5 months (95% CI, 2.689-4.311). Patients with T790M mutation had significantly longer PFS2 (6.3 vs. 2.6 months, p = 0.002) and overall survival (39.8 vs. 23.2 months, p = 0.044) than those without. CONCLUSION Patients with secondary T790M mutation at the time of progression having gradual or local progression after acquired resistance to EGFR-TKI benefit more from EGFR-TKI treatment beyond progression compared to those without T790M mutation.

EBUS-TBNA Provides Highest RNA Yield for Multiple Biomarker Testing from Routinely Obtained Small Biopsies in Non-Small Cell Lung Cancer Patients - A Comparative Study of Three Different Minimal Invasive Sampling Methods

Background Multiple biomarker testing is necessary to facilitate individualized treatment of lung cancer patients. More than 80% of lung cancers are diagnosed based on very small tumor samples. Often there is not enough tissue for molecular analysis. We compared three minimal invasive sampling methods with respect to RNA quantity for molecular testing. Methods 106 small biopsies were prospectively collected by three different methods forceps biopsy, endobronchial ultrasound (EBUS) guided transbronchial needle aspiration (TBNA), and CT-guided core biopsy. Samples were split into two halves. One part was formalin fixed and paraffin embedded for standard pathological evaluation. The other part was put in RNAlater for immediate RNA/DNA extraction. If the pathologist confirmed the diagnosis of non-small cell lung cancer(NSCLC), the following molecular markers were tested: EGFR mutation, ERCC1, RRM1 and BRCA1. Results Overall, RNA-extraction was possible in 101 out of 106 patients (95.3%). We found 49% adenocarcinomas, 38% squamouscarcinomas, and 14% non-otherwise-specified(NOS). The highest RNA yield came from endobronchial ultrasound guided needle aspiration, which was significantly higher than bronchoscopy (37.74±41.09 vs. 13.74±15.53 ng respectively, P = 0.005) and numerically higher than CT-core biopsy (37.74±41.09 vs. 28.72±44.27 ng respectively, P = 0.244). EGFR mutation testing was feasible in 100% of evaluable patients and its incidence was 40.8%, 7.9% and 14.3% in adenocarcinomas, squamouscarcinomas and NSCLC NOS subgroup respectively. There was no difference in the feasibility of molecular testing between the three sampling methods with feasibility rates for ERCC1, RRM1 and BRCA1 of 91%, 87% and 81% respectively. Conclusion All three methods can provide sufficient tumor material for multiple biomarkers testing from routinely obtained small biopsies in lung cancer patients. In our study EBUS guided needle aspiration provided the highest amount of tumor RNA compared to bronchoscopy or CT guided core biopsy. Thus EBUS should be considered as an acceptable option for tissue acquisition for molecular testing.