Rapid KRAS, EGFR, BRAF and PIK3CA mutation analysis of fine needle aspirates from non-small-cell lung cancer using allele-specific qPCR

Endobronchial Ultrasound Guided Transbronchial Needle Aspiration (EBUS-TBNA) and Trans-esophageal Ultrasound Scanning with Fine Needle Aspiration (EUS-FNA) are important, novel techniques for the diagnosis and staging of non-small cell lung cancer (NSCLC) that have been incorporated into lung cancer staging guidelines. To guide and optimize treatment decisions, especially for NSCLC patients in stage III and IV, EGFR and KRAS mutation status is often required. The concordance rate of the mutation analysis between these cytological aspirates and histological samples obtained by surgical staging is unknown. Therefore, we studied the extent to which allele-specific quantitative real-time PCR with hydrolysis probes could be reliably performed on EBUS and EUS fine needle aspirates by comparing the results with histological material from the same patient. We analyzed a series of 43 NSCLC patients for whom cytological and histological material was available. We demonstrated that these standard molecular techniques can be accurately applied on fine needle cytological aspirates from NSCLC patients. Importantly, we show that all mutations detected in the histological material of primary tumor were also identified in the cytological samples. We conclude that molecular profiling can be reliably performed on fine needle cytology aspirates from NSCLC patients.     

Transmission of synovial sarcoma from a single multi-organ donor to three transplant recipients: case report

Quick and reliable testing of EGFR and KRAS is needed in non-small cell lung cancer (NSCLC) to ensure optimal decision-making for targeted therapy. The Idylla™ platform was designed for Formalin-Fixed Paraffin-Embedded (FFPE) tissue sections but recently several studies were published that evaluated its potential for cytological specimens. This study aimed to validate the Idylla™ platform for the detection of EGFR/KRAS mutations in cytological NSCLC samples prepared as cytoblocks using AGAR and paraffin embedding. The KRAS Idylla™ test were performed on 11 specimens with a known KRAS mutation. The EGFR Idylla™ test was performed on 18 specimens with a known primary EGFR mutation and 7 specimens with a primary EGFR-EGFR T790M resistance mutation combination. Concordant KRAS and primary EGFR mutations were detected for both KRAS and primary EGFR mutations. Samples with a total CQ value of < 26 could be considered negative. Samples with a total CQ value of > 26 could not be assessed (probability of false-negative). In specimens with a primary EGFR-EGFR T790M resistance mutation combination, 5/7 cases were not concordant. Our results confirm the conclusion of recent reports that the Idylla™EGFR assay is not suitable in a resistance to EGFR TKI setting, also not in our cytological NSCLC samples prepared as cytoblocks using AGAR and paraffin embedding. KRAS and primary EGFR mutations were detected using the Idylla™ assays in virtually all cytological NSCLC samples. This analysis was rapid and time-saving compared to other mutation detection assays and may be useful if the amount of material is insufficient to perform a full set of molecular tests.     

Screening for EGFR and KRAS mutations in endobronchial ultrasound derived transbronchial needle aspirates in non-small cell lung cancer using COLD-PCR

EGFR mutations correlate with improved clinical outcome whereas KRAS mutations are associated with lack of response to tyrosine kinase inhibitors in patients with non-small cell lung cancer (NSCLC). Endobronchial ultrasound (EBUS)-transbronchial needle aspiration (TBNA) is being increasingly used in the management of NSCLC. Co-amplification at lower denaturation temperature (COLD)-polymerase chain reaction (PCR) (COLD-PCR) is a sensitive assay for the detection of genetic mutations in solid tumours. This study assessed the feasibility of using COLD-PCR to screen for EGFR and KRAS mutations in cytology samples obtained by EBUS-TBNA in routine clinical practice. Samples obtained from NSCLC patients undergoing EBUS-TBNA were evaluated according to our standard clinical protocols. DNA extracted from these samples was subjected to COLD-PCR to amplify exons 18-21 of EGFR and exons two and three of KRAS followed by direct sequencing. Mutation analysis was performed in 131 of 132 (99.3%) NSCLC patients (70F/62M) with confirmed lymph node metastases (94/132 (71.2%) adenocarcinoma; 17/132 (12.8%) squamous cell; 2/132 (0.15%) large cell neuroendocrine; 1/132 (0.07%) large cell carcinoma; 18/132 (13.6%) NSCL-not otherwise specified (NOS)). Molecular analysis of all EGFR and KRAS target sequences was achieved in 126 of 132 (95.5%) and 130 of 132 (98.4%) of cases respectively. EGFR mutations were identified in 13 (10.5%) of fully evaluated cases (11 in adenocarcinoma and two in NSCLC-NOS) including two novel mutations. KRAS mutations were identified in 23 (17.5%) of fully analysed patient samples (18 adenocarcinoma and five NSCLC-NOS). We conclude that EBUS-TBNA of lymph nodes infiltrated by NSCLC can provide sufficient tumour material for EGFR and KRAS mutation analysis in most patients, and that COLD-PCR and sequencing is a robust screening assay for EGFR and KRAS mutation analysis in this clinical context.     

Chronic Obstructive Pulmonary Disease-Related Non-Small-Cell Lung Cancer Exhibits a Low Prevalence of EGFR and ALK Driver Mutations

Lung cancer and chronic obstructive pulmonary disease (COPD) are two major lung diseases. Epidermal growth factor receptor (EGFR) mutations, v‐Ki‐ras2 Kirsten rat sarcoma (KRAS) mutations and anaplastic lymphoma kinase (ALK) gene rearrangements represent driver mutations that are frequently assessed on initial evaluation of non-small-cell lung cancer (NSCLC). The present study focused on the expression of driver mutations in NSCLC patients presenting with COPD and further evaluated the association between NSCLC and COPD. Data from 501 consecutive patients with histologically proven recurrent or metastatic NSCLC were analyzed retrospectively. The patients underwent spirometry and genotyping of EGFR, ALK, and KRAS in tissue samples. Patient characteristics and expression of driver mutations were compared between the COPD and non-COPD groups.Among 350 patients with spirometric results, 106 (30.3%) were diagnosed with COPD, 108 (30.9%) had EGFR mutations, 31 (8.9%) had KRAS mutations, and 34 (9.7%) showed ALK rearrangements. COPD was independently associated with lower prevalences of EGFR mutations (95% confidence interval [CI], 0.254–0.931, p = 0.029) and ALK rearrangements (95% CI, 0.065–0.600, p = 0.004). The proportions of EGFR mutations and ALK rearrangements decreased as the severity of airflow obstruction increased (p = 0.001). In never smokers, the prevalence of EGFR mutations was significantly lower in the COPD group than in the non-COPD group (12.7% vs. 49.0%, p = 0.002). COPD-related NSCLC patients exhibited low prevalences of EGFR mutations and ALK rearrangements compared with the non-COPD group. Further studies are required regarding the molecular mechanisms underlying lung cancer associated with COPD.     

Cytoplasmic sequestration of the tumor suppressor p53 by a heat shock protein 70 family member, mortalin, in human colorectal adenocarcinoma cell lines

Lung cancer, predominantly non-small cell lung cancer (NSCLC), remains the leading cause of cancer-related deaths worldwide. Although epidermal growth factor receptor (EGFR) signaling is important and well studied with respect to NSCLC progression, little is known about how miRNAs mediate EGFR signaling to modulate tumorigenesis. To identify miRNAs that target EGFR, we performed a bioinformatics analysis and found that miR-542-5p down-regulates EGFR mRNA and protein expression in human lung cancer cells (H3255, A549, Hcc827). We observed increases in EGFR association with Ago2 in miR-542-5p-transfected cells. Interestingly, we observed an inverse correlation of miR-542-5p expression and EGFR protein levels in human lung cancer tissue samples, suggesting that miR-542-5p directly targets EGFR mRNA. Furthermore, we found that miR-542-5p inhibited the growth of human lung cancer cells. Our findings suggest that miR-542-5p may act as an important modulator of EGFR-mediated oncogenesis, with potential applications as a novel therapeutic target in lung cancer.     

EML4-ALK 融合基因在非小细胞肺癌中的研究进展

肺癌是发病率和死亡率最高的恶性肿瘤,分子靶向治疗以其特异性高、副反应轻的特点正日益受到关注。近年来临床研究发现EML4-ALK融合基因是除EGFR突变及KRAS突变之外的另-个重要的酪氨酸激酶抑制剂的作用靶点,该融合基因在年轻、不吸烟或少吸烟、腺癌、无EGFR和KRAS突变的非小细胞肺癌患者中发生率较高,且该融合基因阳性者对酪氨酸激酶抑制剂耐药,对于ALK抑制剂(如克唑替尼)则有良好的治疗反应,关于该药的临床试验表明:总有效率达57%(46例确定为部分缓解,1例确定为完全缓解),估计6个月无进展生存概率为72%,常见的副反应是1、2级胃肠道反应。该基因及该药的发现为非小细胞肺癌患者带来了希望。     

Combinatorial Action of MicroRNAs let-7 and miR-34 Effectively Synergizes with Erlotinib to Suppress Non-small Cell Lung Cancer Cell Proliferation

Lung cancer represents the leading cause of cancer-related deaths in men and women worldwide. Targeted therapeutics, including the epidermal growth factor receptor (EGFR) inhibitor erlotinib, have recently emerged as clinical alternatives for the treatment of non-small cell lung cancer (NSCLC). However, the development of therapeutic resistance is a major challenge, resulting in low 5-year survival rates. Due to their ability to act as tumor suppressors, microRNAs (miRNAs) are attractive candidates as adjuvant therapeutics for the treatment of NSCLC. In this study, we examine the ability of 2 tumor suppressor miRNAs, let-7b and miR-34a to sensitize KRAS;TP53 mutant non-small cell lung cancer cells to the action of erlotinib. Treatment with these miRNAs, individually or in combination, resulted in synergistic potentiation of the anti-proliferative effects of erlotinib. This effect was observed over a wide range of miRNA and erlotinib interactions, suggesting that let-7b and miR-34a target oncogenic pathways beyond those inhibited by EGFR. Combinatorial treatment with let-7b and miR-34a resulted in the strongest synergy with erlotinib, indicating that these miRNAs can effectively target multiple cellular pathways involved in cancer cell proliferation and resistance to erlotinib. Together, our findings indicate that NSCLC cells can be effectively sensitized to erlotinib by supplementation with tumor suppressor miRNAs, and suggest that the use of combinations of miRNAs as adjuvant therapeutics for the treatment of lung cancer is a viable clinical strategy.     

The positive impact of cytological specimens for EGFR mutation testing in non‐small cell lung cancer: a single South East Asian laboratory’s analysis of 670 cases

B. Pang, D. Matthias, C.W. Ong, A.N. Dhewar, S. Gupta, G.L. Lim, M.‐E. Nga, J.E. Seet, A. Qasim, T.‐M. Chin, R. Soo, R. Soong and M. Salto‐Tellez The positive impact of cytological specimens for EGFR mutation testing in non‐small cell lung cancer: a single South East Asian laboratory’s analysis of 670 cases Objectives: To compare the rejection rates of non‐small cell lung cancer (NSCLC) samples obtained by differing sampling methods for testing by Sanger sequencing for epidermal growth factor receptor (EGFR) mutations. To assess the association between unsatisfactory outcomes and the quantity of DNA extracted from cytological versus histological samples. Methods: Six hundred and seventy NSCLC samples referred to our centre from 2008 to 2010 were reviewed as a consequence of sample rejection, presence of EGFR mutations, cytological versus histological sampling methods, DNA quantity and the unsatisfactory genotyping rate. Results: Eighty samples were rejected for testing in similar proportions of histological and cytological samples (11.9% versus 10.9%) usually (n = 75) because the amount of cellular material was judged insufficient in small biopsies or cytology samples. The remaining 590 samples on which EGFR testing was attempted yielded 51 (8.6%) unsatisfactory test outcomes caused by failure of the polymerase chain reaction (PCR) (n = 47 cases), uninterpretable Sanger chromatograms (n = 3 cases) and insufficient DNA extracted for PCR (n = 1 case). The difference in rates of unsatisfactory outcomes between cytological samples (seven of 147 samples or 4.7%) versus tissue samples (44 of 443 samples or 9.9%) was clinically relevant but not statistically significant (Mann–Whitney test; P < 0.081). There was no association between the concentration of DNA extracted and the likelihood of an unsatisfactory analysis; which was similar in all types of sections (large and small) while 0% of 37 cytology slides were unsatisfactory. Conclusions: Utilizing cytology samples for EGFR testing avoids unnecessary patient re‐biopsing and yields a clinically superior satisfactory rate to the overall satisfactory rate of tissue biopsies of NSCLC. The quality rather than quantity of DNA extracted may be a more important determinant of a satisfactory result.     

miR-146a Inhibits Cell Growth,Cell Migration and Induces Apoptosis in Non-Small Cell Lung Cancer Cells

Aberrant expression of microRNA-146a (miR-146a) has been reported to be involved in the development and progression of various types of cancers. However, its role in non-small cell lung cancer (NSCLC) has not been elucidated. The aim of this study was to investigate the contribution of miR-146a to various aspects of the malignant phenotype of human NSCLCs. In functional experiments, miR-146a suppressed cell growth, induced cellular apoptosis and inhibited EGFR downstream signaling in five NSCLC cell lines (H358, H1650, H1975, HCC827 and H292). miR-146a also inhibited the migratory capacity of these NSCLC cells. On the other hand, miR-146a enhanced the inhibition of cell proliferation by drugs targeting EGFR, including both TKIs (gefitinib, erlotinib, and afatinib) and a monoclonal antibody (cetuximab). These effects were independent of the EGFR mutation status (wild type, sensitizing mutation or resistance mutation), but were less potent compared to the effects of siRNA targeting of EGFR. Our results suggest that these effects of miR-146a are due to its targeting of EGFR and NF-κB signaling. We also found, in clinical formalin fixed paraffin embedded (FFPE) lung cancer samples, that low expression of miR-146a was correlated with advanced clinical TNM stages and distant metastasis in NSCLC (P<0.05). The patients with high miR-146a expression in their tumors showed longer progression-free survival (25.6 weeks in miR-146a high patients vs. 4.8 weeks in miR-146a low patients, P<0.05). miR-146a is therefore a strong candidate prognostic biomarker in NSCLC. Thus inducing miR-146a might be a therapeutic strategy for NSCLC.     

CBL Is Frequently Altered in Lung Cancers: Its Relationship to Mutations in MET and EGFR Tyrosine Kinases

Background

Non-small cell lung cancer (NSCLC) is a heterogeneous group of disorders with a number of genetic and proteomic alterations. c-CBL is an E3 ubiquitin ligase and adaptor molecule important in normal homeostasis and cancer. We determined the genetic variations of c-CBL, relationship to receptor tyrosine kinases (EGFR and MET), and functionality in NSCLC.

Methods and Findings

Using archival formalin-fixed paraffin embedded (FFPE) extracted genomic DNA, we show that c-CBL mutations occur in somatic fashion for lung cancers. c-CBL mutations were not mutually exclusive of MET or EGFR mutations; however they were independent of p53 and KRAS mutations. In normal/tumor pairwise analysis, there was significant loss of heterozygosity (LOH) for the c-CBL locus (22%, n = 8/37) and none of these samples revealed any mutation in the remaining copy of c-CBL. The c-CBL LOH also positively correlated with EGFR and MET mutations observed in the same samples. Using select c-CBL somatic mutations such as S80N/H94Y, Q249E and W802* (obtained from Caucasian, Taiwanese and African-American samples, respectively) transfected in NSCLC cell lines, there was increased cell viability and cell motility.

Conclusions

Taking the overall mutation rate of c-CBL to be a combination as somatic missense mutation and LOH, it is clear that c-CBL is highly mutated in lung cancers and may play an essential role in lung tumorigenesis and metastasis.     

Molecular Typing of Lung Adenocarcinoma on Cytological Samples Using a Multigene Next Generation Sequencing Panel

Identification of driver mutations in lung adenocarcinoma has led to development of targeted agents that are already approved for clinical use or are in clinical trials. Therefore, the number of biomarkers that will be needed to assess is expected to rapidly increase. This calls for the implementation of methods probing the mutational status of multiple genes for inoperable cases, for which limited cytological or bioptic material is available. Cytology specimens from 38 lung adenocarcinomas were subjected to the simultaneous assessment of 504 mutational hotspots of 22 lung cancer-associated genes using 10 nanograms of DNA and Ion Torrent PGM next-generation sequencing. Thirty-six cases were successfully sequenced (95%). In 24/36 cases (67%) at least one mutated gene was observed, including EGFR, KRAS, PIK3CA, BRAF, TP53, PTEN, MET, SMAD4, FGFR3, STK11, MAP2K1. EGFR and KRAS mutations, respectively found in 6/36 (16%) and 10/36 (28%) cases, were mutually exclusive. Nine samples (25%) showed concurrent alterations in different genes. The next-generation sequencing test used is superior to current standard methodologies, as it interrogates multiple genes and requires limited amounts of DNA. Its applicability to routine cytology samples might allow a significant increase in the fraction of lung cancer patients eligible for personalized therapy.     

MicroRNA-429 induces tumorigenesis of human non-small cell lung cancer cells and targets multiple tumor suppressor genes

Lung cancer is the major cause of cancer death globally. MicroRNAs are evolutionally conserved small noncoding RNAs that are critical for the regulation of gene expression. Aberrant expression of microRNA (miRNA) has been implicated in cancer initiation and progression. In this study, we demonstrated that the expression of miR-429 are often upregulated in non-small cell lung cancer (NSCLC) compared with normal lung tissues, and its expression level is also increased in NSCLC cell lines compared with normal lung cells. Overexpression of miR-429 in A549 NSCLC cells significantly promoted cell proliferation, migration and invasion, whereas inhibition of miR-429 inhibits these effects. Furthermore, we demonstrated that miR-429 down-regulates PTEN, RASSF8 and TIMP2 expression by directly targeting the 3′-untranslated region of these target genes. Taken together, our results suggest that miR-429 plays an important role in promoting the proliferation and metastasis of NSCLC cells and is a potential target for NSCLC therapy.     

A Mathematical Model for MicroRNA in Lung Cancer

Lung cancer is the leading cause of cancer-related deaths worldwide. Lack of early detection and limited options for targeted therapies are both contributing factors to the dismal statistics observed in lung cancer. Thus, advances in both of these areas are likely to lead to improved outcomes. MicroRNAs (miRs or miRNAs) represent a class of non-coding RNAs that have the capacity for gene regulation and may serve as both diagnostic and prognostic biomarkers in lung cancer. Abnormal expression patterns for several miRNAs have been identified in lung cancers. Specifically, let-7 and miR-9 are deregulated in both lung cancers and other solid malignancies. In this paper, we construct a mathematical model that integrates let-7 and miR-9 expression into a signaling pathway to generate an in silico model for the process of epithelial mesenchymal transition (EMT). Simulations of the model demonstrate that EGFR and Ras mutations in non-small cell lung cancers (NSCLC), which lead to the process of EMT, result in miR-9 upregulation and let-7 suppression, and this process is somewhat robust against random input into miR-9 and more strongly robust against random input into let-7. We elected to validate our model in vitro by testing the effects of EGFR inhibition on downstream MYC, miR-9 and let-7a expression. Interestingly, in an EGFR mutated lung cancer cell line, treatment with an EGFR inhibitor (Gefitinib) resulted in a concentration specific reduction in c-MYC and miR-9 expression while not changing let-7a expression. Our mathematical model explains the signaling link among EGFR, MYC, and miR-9, but not let-7. However, very little is presently known about factors that regulate let-7. It is quite possible that when such regulating factors become known and integrated into our model, they will further support our mathematical model.     

Knockdown of lncRNA ZFAS1-suppressed non–small cell lung cancer progression via targeting the miR-150-5p/HMGA2 signaling

Non–small cell lung cancer (NSCLC) is the main type of lung malignancy. Early diagnosis and treatments for NSCLC are far from satisfactory due to the limited knowledge of the molecular mechanisms regarding NSCLC progression. Long noncoding RNA (lncRNA) ZNFX1 antisense RNA1 (ZFAS1) has been implicated for its functional role in the progression of malignant tumors. This study aimed to determine the ZFAS1 expression from lung cancer clinical samples and to explore the molecular mechanisms underlying ZFAS1-modulated NSCLC progression. Experimental assays revealed that clinical samples and cell lines of lung malignant tumors showed an upregulation of ZFSA1. ZFAS1 expression was markedly upregulated in the lung tissues from patients with advanced stage of this malignancy. The loss-of-function assays showed that knockdown of ZFAS1-suppressed NSCLC cell proliferative, as well as invasive potentials, increased NSCLC cell apoptotic rates in vitro and also attenuated tumor growth of NSCLC cells in the nude mice. Further experimental evidence showed that ZFAS1 inversely affected miR-150-5p expression and positively affected high-mobility group AT-hook 2 (HMGA2) expression in NSCLC cell lines. MiR-150-5p inhibition or HMGA2 overexpression counteracted the effects of ZFAS1 knockdown on NSCLC cell proliferative, invasive potentials and apoptotic rates. In light of examining the clinical lung cancer samples, miR-150-5p expression was downregulated and the HMGA2 expression was highly expressed in the lung cancer tissues compared with normal ones; the ZFAS1 expression showed a negative correlation with miR-150-5p expression but a positive correlation with HMGA2 expression in lung cancer tissues. To summarize, we, for the first time, demonstrated the inhibitory effects of ZFAS1 knockdown on NSCLC cell progression, and the results from mechanistic studies indicated that ZFAS1-mediated NSCLC progression cells via targeting miR-150-5p/HMGA2 signaling.     

miR-138-5p reverses gefitinib resistance in non-small cell lung cancer cells via negatively regulating G protein-coupled receptor 124

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) such as gefitinib are clinically effective treatments for non-small cell lung cancer (NSCLC) patients with EGFR activating mutations. However, therapeutic effect is ultimately limited by the development of acquired TKI resistance. MicroRNAs (miRNAs) represent a category of small non-coding RNAs commonly deregulated in human malignancies. The aim of this study was to investigate the role of miRNAs in gefitinib resistance. We established a gefitinib-resistant cell model (PC9GR) by continually exposing PC9 NSCLC cells to gefitinib for 6 months. MiRNA microarray screening revealed miR-138-5p showed the greatest downregulation in PC9GR cells. Re-expression of miR-138-5p was sufficient to sensitize PC9GR cells and another gefitinib-resistant NSCLC cell line, H1975, to gefitinib. Bioinformatics analysis and luciferase reporter assay showed that G protein-coupled receptor124 (GPR124) was a direct target of miR-138-5p. Experimental validation demonstrated that expression of GPR124 was suppressed by miR-138-5p on protein and mRNA levels in NSCLC cells. Furthermore, we observed an inverse correlation between the expression of miR-138-5p and GPR124 in lung adenocarcinoma specimens. Knockdown of GPR124 mimicked the effects of miR-138-5p on the sensitivity to gefitinib. Collectively, our results suggest that downregulation of miR-138-5p contributes to gefitinib resistance and that restoration of miR-138-5p or inhibition GPR124 might serve as potential therapeutic approach for overcoming NSCLC gefitinib resistance.     

Absence of evidence for epidermal growth factor receptor and human homolog of the Kirsten rat sarcoma-2 virus oncogene mutations in breast cancer

Aims: The epidermal growth factor receptor (EGFR) is an available target of effective anti-EGFR therapy for human breast cancer. KRAS, the human homolog of the Kirsten rat sarcoma-2 virus oncogene, encodes a main downstream signaling molecule in the EGFR pathway. The aim of this study was to assess the presence of EGFR and KRAS gene mutations in breast cancer. Materials and methods: EGFR and KRAS gene mutations were investigated in formalin-fixed, paraffin-embedded tissues from 143 Chinese female patients with breast cancer by means of real-time quantitative polymerase chain reaction (RT-PCR). Results: Based on RT-PCR, 2/143 (1.4%) samples and 1/143 (0.7%) had EGFR and KRAS gene mutations, respectively. Overall, none of the cases was identified with mutations of both of these two genes. Conclusions: In this study, both EGFR and KRAS mutations were present rarely in this cohort of samples with breast cancer. This suggested that mutation analyses for EGFR and KRAS are not useful as screening tests for sensitivity to anti-EGFR therapy for breast carcinomas.     

MicroRNA-486 as a Biomarker for Early Diagnosis and Recurrence of Non-Small Cell Lung Cancer

Background

Non-small cell lung cancer (NSCLC) is a leading cause of cancer death worldwide. Early diagnosis is essential for improvements of prognosis and survival of the patients. Currently, there is no effective biomarker available in clinical settings for early detection of lung cancer. Altered expressions in many cancer types including NSCLC and stable existence in plasma make microRNAs (miRNAs) a group of potentially useful biomarkers for clinical assessments of patients with NSCLC.

Objectives

To evaluate the potential values of miRNAs as blood-based biomarkers for early diagnosis and prognosis in NSCLC patients.

Methods

Peripheral blood samples from healthy volunteers and early-staged NSCLC patients before and after surgery were collected, and plasma was separated. Expression of ten miRNAs in the plasma and tumor sections of the patients was detected by quantitative real-time polymerase chain reaction.

Results

MiRNA (miR)-486 and miR-150 were found to significantly distinguish lung cancer patients from healthy volunteers. Area under curve of miR-486 and miR-150 were 0.926 (sensitivity, 0.909; specificity, 0.818) and 0.752 (sensitivity, 0.818; specificity, 0.818), respectively. In response to therapy, patients with down-regulated miR-486 expression showed prolonged recurrence-free survival than those with un-reduced miR-486 expression (median, unreached vs. 19 months; hazard ratio, 0.1053; 95% confidence interval, 0.01045 to 1.060; P=0.056).

Conclusions

The results suggest that miR-486 and miR-150 could be potential blood-based biomarkers for early diagnosis of NSCLC. Monitoring change of miR-486 expression in plasma might be an effective and non-invasive method for recurrence prediction of early-staged NSCLC patients.     

Two Panels of Plasma MicroRNAs as Non-Invasive Biomarkers for Prediction of Recurrence in Resectable NSCLC

The diagnosis of non-small cell lung carcinoma (NSCLC) at an early stage, as well as better prediction of outcome remains clinically challenging due to the lack of specific and robust non-invasive markers. The discovery of microRNAs (miRNAs), particularly those found in the bloodstream, has opened up new perspectives for tumor diagnosis and prognosis. The aim of our study was to determine whether expression profiles of specific miRNAs in plasma could accurately discriminate between NSCLC patients and controls, and whether they are able to predict the prognosis of resectable NSCLC patients. We therefore evaluated a series of seventeen NSCLC-related miRNAs by quantitative real-time (qRT)-PCR in plasma from 52 patients with I-IIIA stages NSCLC, 10 patients with chronic obstructive pulmonary disease (COPD) and 20-age, sex and smoking status-matched healthy individuals. We identified an eleven-plasma miRNA panel that could distinguish NSCLC patients from healthy subjects (AUC = 0.879). A six-plasma miRNA panel was able to discriminate between NSCLC patients and COPD patients (AUC = 0.944). Furthermore, we identified a three-miRNA plasma signature (high miR-155-5p, high miR-223-3p, and low miR-126-3p) that significantly associated with a higher risk for progression in adenocarcinoma patients. In addition, a three-miRNA plasma panel (high miR-20a-5p, low miR-152-3p, and low miR-199a-5p) significantly predicted survival of squamous cell carcinoma patients. In conclusion, we identified two plasma miRNA expression profiles that may be useful for predicting the outcome of patients with resectable NSCLC.     

Epigenetic regulation of miR-212 expression in lung cancer

Many studies have shown that microRNA expression in cancer may be regulated by epigenetic events. Recently, we found that in lung cancer miR-212 was strongly down-regulated. However, mechanisms involved in the regulation of miR-212 expression are unknown. Therefore, we addressed this point by investigating the molecular mechanisms of miR-212 silencing in lung cancer. We identified histone modifications rather than DNA hypermethylation as epigenetic events that regulate miR-212 levels in NSCLC. Moreover, we found that miR-212 silencing in vivo is closely associated with the severity of the disease.