Erratum: miR-199a-3p/5p regulate tumorgenesis via targeting Rheb in non-small cell lung cancer: Erratum.

[This corrects the article DOI: 10.7150/ijbs.70312.].

HNRNPA2B1 as a potential therapeutic target for thymic epithelial tumor recurrence: An integrative network analysis.

Thymic epithelial tumors (TETs) are rare malignant tumors, and the molecular mechanisms of both primary and recurrent TETs are poorly understood. Here we established comprehensive proteomic signatures of 15 tumors (5 recurrent and 10 non-recurrent) and 15 pair wised tumor adjacent normal tissues. We then proposed an integrative network approach for studying the proteomics data by constructing protein-protein interaction networks based on differentially expressed proteins and a machine learning-based score, followed by network modular analysis, functional enrichment annotation and shortest path inference analysis. Network modular analysis revealed that primary and recurrent TETs shared certain common molecular mechanisms, including a spliceosome module consisting of RNA splicing and RNA processing, but the recurrent TET was specifically related to the ribosome pathway. Applying the shortest path inference to the collected seed gene module identified that the ribonucleoprotein hnRNPA2B1 probably serves as a potential target for recurrent TET therapy. The drug repositioning combined molecular dynamics simulations suggested that the compound ergotamine could potentially act as a repurposing drug to treat recurrent TETs by targeting hnRNPA2B1. Our study demonstrates the value of integrative network analysis to understand proteotype robustness and its relationships with genotype, and provides hits for further research on cancer therapeutics.

miR-199a-3p/5p regulate tumorgenesis via targeting Rheb in non-small cell lung cancer.

Lung cancer is one of the deadliest cancers, in which non-small cell lung cancer (NSCLC) accounting for 85% and has a low survival rate of 5 years. Dysregulation of microRNAs (miRNAs) can participate in tumor regulation and many major diseases. In this study, we found that miR-199a-3p/5p were down-expressed in NSCLC tissue samples, cell lines, and the patient sample database. MiR-199a-3p/5p overexpression could significantly suppress cell proliferation, migration ability and promote apoptosis. Through software prediction, ras homolog enriched in brain (Rheb) was identified as a common target of miR-199a-3p and miR-199a-5p, which participated in regulating mTOR signaling pathway. The same effect of inhibiting NSCLC appeared after down-regulating the expression of Rheb. Furthermore, our findings revealed that miR-199a can significantly inhibit tumor growth and metastasis in vivo, which fully demonstrates that miR-199a plays a tumor suppressive role in NSCLC. In addition, miR-199a-3p/5p has been shown to enhance the sensitivity of gefitinib to EGFR-T790M in NSCLC. Collectively, these results prove that miR-199a-3p/5p can act as cancer suppressor genes to inhibit the mTOR signaling pathway by targeting Rheb, which in turn inhibits the regulatory process of NSCLC. Thus, to investigate the anti-cancer effect of pre-miR-199a/Rheb/mTOR axis in NSCLC, miR-199a-3p and miR-199a-5p have the potential to become an early diagnostic marker or therapeutic target for NSCLC.

miRNA-199a-5p/SLC2A1 axis regulates glucose metabolism in non-small cell lung cancer.

Lung cancer is acknowledged as a common cancer with high morbidity and mortality. MicroRNAs (miRNAs), kind of non-coding single-stranded RNA molecules, can be used in cancer clinical treatments. In this research, miR-199a-5p was seen lowly expressed in NSCLC sera samples. miR-199a-5p suppressed the cell proliferation, migration and arrested cell cycle in NSCLC cell lines. The results showed that SLC2A1 (glucose transporter 1, GLUT1) was a direct target of miR-199a-5p. Downregulation of SLC2A1 could not only inhibit cell proliferation, migration and cell cycle, but also promote cell apoptosis. The data suggests that miR-199a-5p can inhibit glucose metabolism in NSCLC by targeting SLC2A1.This study proves that miR-199a-5p / SLC2A1 can play an essential role in the development of NSCLC by targeting SLC2A1. It puts forward a new approach for clinical treatments of NSCLC.

Novel Tumor-Specific Antigens for Immunotherapy Identified From Multi-omics Profiling in Thymic Carcinomas.

Thymic carcinoma (TC) is the most aggressive thymic epithelial neoplasm. TC patients with microsatellite instability, whole-genome doubling, or alternative tumor-specific antigens from gene fusion are most likely to benefit from immunotherapies. However, due to the rarity of this disease, how to prioritize the putative biomarkers and what constitutes an optimal treatment regimen remains largely unknown. Therefore, we integrated genomic and transcriptomic analyses from TC patients and revealed that frameshift indels in KMT2C and CYLD frequently produce neoantigens. Moreover, a median of 3 fusion-derived neoantigens was predicted across affected patients, especially the CATSPERB-TC2N neoantigens that were recurrently predicted in TC patients. Lastly, potentially actionable alterations with early levels of evidence were uncovered and could be used for designing clinical trials. In summary, this study shed light on our understanding of tumorigenesis and presented new avenues for molecular characterization and immunotherapy in TC.

Downregulation of LINC01296 suppresses non-small-cell lung cancer via targeting miR-143-3p/ATG2B.

The 5-year survival rate of lung cancer is one of the lowest among various malignant tumors. Long noncoding RNAs (lncRNAs), noncoding RNAs longer than 200 nucleotides, can function either as tumor suppressors or as oncogenes. The aim of this study is to investigate the function of lncRNA LINC01296 and its molecular mechanism in non-small-cell lung cancer (NSCLC). According to the Gene Expression Omnibus database, 10 differentially expressed lncRNAs in NSCLC cells and patient tissues are upregulated. LINC01296 is the one with the most significant overexpression. Knockdown of LINC01296 inhibits the growth and migration, arrests the cell cycle, and promotes the apoptosis of NSCLC cells. Knocking down LINC01296 in vivo suppresses tumor growth and metastasis. LINC01296 also acts as the sponge of miR-143-3p. Lowering the expression of LINC01296 leads to decreased expression of autophagy-related 2B (ATG2B), a target gene of miR-143-3p. Moreover, downregulation of LINC01296 promotes paclitaxel sensitivity in NSCLC. These results demonstrated that the LINC01296/miR-143-3p/ATG2B axis is crucial in promoting the development of NSCLC and paclitaxel resistance. Our study may provide new ideas for the further research of clinical chemotherapy of NSCLC in the near future.

Tissue signals imprint Aiolos expression in ILC2s to modulate type 2 immunity.

Group 2 innate lymphoid cells (ILC2s) manifest tissue heterogeneity and are crucial modulators of regional immune responses. The molecular mechanisms regulating tissue ILC2 properties remain elusive. Here, we interrogate the signatures of ILC2s from five tissues at the transcriptome and epigenetic level. We have found that tissue microenvironment strongly shapes ILC2 identities. The intestine induces Aiolos+ILC2s, whereas lung and pancreas enhance Galectin-1+ILC2s. Though being a faithful gut ILC2 feature under the steady state, Aiolos is induced in non-intestinal ILC2s by pro-inflammatory cytokines. Specifically, IL-33 stimulates Aiolos expression in both human and mouse non-intestinal ILC2s. Functionally, Aiolos facilitates eosinophil recruitment by supporting IL-5 production and proliferation of ST2+ILC2s through inhibiting PD-1. At the epigenetic level, ILC2 tissue characters are imprinted by open chromatin regions (OCRs) at non-promoters. Intestinal-specific transcription factor aryl hydrocarbon receptor (Ahr) binds to Ikzf3 (encoding Aiolos) locus, increases the accessibility of an intestinal ILC2-specific OCR, and promotes the Ikzf3 transcription by enhancing H3K27ac. Consequently, Ahr prevents ILC2s entering an "exhausted-like" state through sustaining Aiolos expression. Our work elucidates mechanism of ILC2 tissue adaptation and highlights Aiolos as a potential target of type 2 inflammation.

miR-224-5p-enriched exosomes promote tumorigenesis by directly targeting androgen receptor in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is the most common form of cancer, resulting in cancer-related deaths worldwide. Exosomes, a subclass of extracellular vesicles, are produced and secreted from various types of cells, including cancer cells. Cancer-derived exosomes can deliver nucleic acids, proteins, and lipids to provide a favorable microenvironment that supports tumor growth through enhancing cell proliferation and metastasis. Our results showed that miR-224-5p was upregulated in NSCLC patient tissues and cell lines, with a tumor-promoting phenotype. Meanwhile, exosome-derived miR-224-5p induced cell proliferation and metastasis in NSCLC and human lung cells. Moreover, we characterized the androgen receptor (AR) as a direct target of miR-224-5p. Tumor xenograft assay experiments revealed that overexpression of miR-224-5p drove NSCLC tumor growth via the suppression of AR and the mediation of epithelial-mesenchymal transition (EMT). Collectively, our results suggest that miR-224-5p-enriched exosomes promote tumorigenesis by directly targeting AR in NSCLC, which may provide novel potential therapeutic and preventive targets for NSCLC.

Higher expression of miR-150-5p promotes tumorigenesis by suppressing LKB1 in non-small cell lung cancer.

Lung cancer is one of the most malignant tumors that can form in the human. MicroRNAs (MiRNAs) play significant role in tumor progression. Human lung cancer tissues and cell lines were used to determine miR-150-5p respectively, and Liver Kinase B1 (LKB1) expression using quantitative real-time PCR (qRT-PCR). The data analysis website Kaplan-Meier Plotter (database obtained from The Cancer Genome Atlas) was used to perform a survival analysis with LKB1 levels. Using the appropriate assays, the function of miR-150-5p was also detected in cellular proliferation, migration and cell apoptosis as well as cell cycle. Results revealed that miR-150-5p was upregulated in non-small cell lung cancer (NSCLC) tissue and cell lines. In NSCLC, miR-150-5p promoted cellular proliferation and migration, but decreased cellular apoptosis. Conversely, miR-150-5p inhibition suppressed cellular growth. These results further revealed a network of cellular signaling for miR-150-5p to target LKB1. Ectopic expression of LKB1 can mitigate the tumor-promoting function of miR-150-5p. Collectively, these results indicated that miR-150-5p may promote lung cancer by inhibiting the suppressor gene LKB1 in NSCLC.

The MiR-17-92 Gene Cluster is a Blood-Based Marker for Cancer Detection in Non-Small-Cell Lung Cancer.

BACKGROUND: Lung cancer is one of the most malignant cancers threatening human health. The miR-17-92 gene cluster is a highly conserved oncogene cluster encoding 6 miRNAs: miR-17, miR-18a, miR-19a, miR-19b-1, miR-20a and miR-92a. This study explored whether these miRNAs can be used as diagnostic markers for non-small-cell lung cancer (NSCLC). METHODS: Serum samples were collected from healthy subjects (n = 23) and NSCLC patients at various stages (n = 74). Serum RNA was extracted by the TRIzol-glycogen method, and cDNA libraries were constructed by reverse transcription. Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to detect the expression levels of the 6 miRNAs. RESULTS: The expression levels of the 6 miRNAs varied in different stages of NSCLC. Thus, 2 receiver operating characteristic (ROC) curves, that is, normal subjects and stage I-III patients and normal subjects and stage IV patients, of each miRNA were established to determine the interval of normal ΔCt values. The 2 areas under the curve (AUCs) of each miRNA were investigated (miR-17: 0.8097 and 1.000; miR-18a: 0.7388 and 0.9907; miR-19a/19b: 0.8451 and 0.5104; miR-20a: 0.8975 and 1.000; miR-92a: 0.8097 and 0.8342). In addition, a high positive correlation was discovered between miR-17 and miR-20a expression. Combining these 2 miRNAs can improve the screening effect of NSCLC. CONCLUSION: The miR-17-92 gene cluster can likely serve as a diagnostic marker in NSCLC.

Deciphering tissue-based proteome signatures revealed novel subtyping and prognostic markers for thymic epithelial tumors.

Thymic epithelial tumors (TETs) belong to a group of tumors that rarely occur, but have unresolved mechanisms and heterogeneous clinical behaviors. Current care of TET patients demands biomarkers of high sensitivity and specificity for accurate histological classification and prognosis management. In this study, 134 fresh-frozen tissue samples (84 tumor, 40 tumor adjacent, and 10 normal thymus) were recruited to generate a quantitative and systematic view of proteomic landscape of TETs. Among them, 90 samples were analyzed by data-independent acquisition mass spectrometry (DIA-MS) leading to discovery of novel classifying molecules among different TET subtypes. The correlation between clinical outcome and the identified molecules was probed, and the prioritized proteins of interest were further validated on the remaining samples (n = 44) via parallel reaction monitoring (PRM) as well as immunohistochemical and confocal imaging analysis. In particular, two proteins, the cellular mRNA deadenylase CCR4 (carbon catabolite repressor 4)-NOT (negative on TATA) complex subunit 2/9 (CNOT2/9) and the serine hydroxymethyltransferase that catalyzes the reversible interconversions of serine and glycine (SHMT1), were found at dramatic low levels in the thymic epithelia of more malignant subtype, thymic squamous cell carcinoma (TSCC). Interestingly, the mRNA levels of these two genes were shown to be closely correlated with prognosis of the TET patients. These results extended the existing human tissue proteome atlas and allowed us to identify several new protein classifiers for TET subtyping. Newly identified subtyping and prognosis markers, CNOT2/9 and SHMT1, will expand current diagnostic arsenal in terms of higher specificity and prognostic insights for TET diagnosis and management.

Using proteomic profiling to characterize protein signatures of different thymoma subtypes.

BACKGROUND: Histology is a traditional way to classify subtypes of thymoma, because of low cost and convenience. Yet, due to the diverse morphology of thymoma, this method increases the complexity of histopathologic classification, and requires experienced experts to perform correct diagnosis. Therefore, in this study, we developed an alternative method by identifying protein biomarkers in order to assist clinical practitioners to make right classification of thymoma subtypes. METHODS: In total, 204 differentially expressed proteins in three subtypes of thymoma, AB, B2, and B3, were identified using mass spectrometry. Pathway analysis showed that the differentially expressed proteins in the three subtypes were involved in activation-related, signaling transduction-related and complement system-related pathways. To predict the subtypes of thymoma using the identified protein signatures, a support vector machine algorithm was used. Leave-one-out cross validation methods and receiver operating characteristic analysis were used to evaluate the predictive performance. RESULTS: The mean accuracy rates were > 80% and areas under the curve were ≧0.93 across these three subtypes. Especially, subtype B3 had the highest accuracy rate (96%) and subtype AB had the greatest area under the curve (0.99). One of the differentially expressed proteins COL17A2 was further validated using immunohistochemistry. CONCLUSIONS: In summary, we identified specific protein signatures for accurately classifying subtypes of thymoma, which could facilitate accurate diagnosis of thymoma patients.

Cryptotanshinone Suppresses Non-Small Cell Lung Cancer via microRNA-146a-5p/EGFR Axis.

Epidermal growth factor receptor (EGFR), a cancer-driven gene, plays an important role in tumorigenesis of lung cancer. Cryptotanshinone (CT) is the main constituent of salia miltiorrhiza and has been found to affect tumor progression. However, the mechanism of CT on lung cancer is still not clear. Here we found that CT could suppress the proliferation of non-small cell lung cancer (NSCLC) by inhibiting EGFR. We further confirmed that knockdown of EGFR also suppressed cell proliferation and arrested cell cycle progression. Furthermore, we evaluated EGFR was a direct target gene of miR-146a-5p which was upregulated by CT. In general, our results proved that CT could restrain NSCLC via miR-146a-5p/EGFR axis. CT and miR-146a-5p have the potential to be positive candidates in drug development of NSCLC.

Oncogenic microRNA-411 promotes lung carcinogenesis by directly targeting suppressor genes SPRY4 and TXNIP.

Lung cancer is one of the most common malignant diseases globally, composed of non-small cell lung cancer (NSCLC, 85%) and small cell lung cancer (SCLC, 15%). MicroRNAs (miRNAs) are single-stranded noncoding RNAs having important roles in lung cancer development. miR-411-5p/3p were reported to be increased significantly in human NSCLC tissues and cell lines. Moreover, miR-411-5p/3p overexpression could accelerate cell proliferation and migration, and impede cell apoptosis in NSCLC cell lines. Mechanically, SPRY4 is confirmed a direct target of miR-411-5p/3p. Furthermore, our findings showed that miR-411-5p/3p promoted lung tumor growth in vivo, decreased SPRY4 expression dramatically, and induced EGFR, AKT signaling activation, as well as epithelial-mesenchymal transition (EMT) simultaneously in tumor tissues. In addition, we showed that miR-411-5p also targeted tumor suppressor TXNIP, involved in regulating positively cell cycle progress in SPC-A1 cells rather than in H1299. Whether cell specificity of low TXNIP mRNA level in H1299 is responsible for the different response to cell cycle between H1299 and SPC-A1 would need further explorations. Collectively, these results suggest that miR-411-5p/3p are required for NSCLC development by suppressing SPRY4 and TXNIP; thus, the miR-411-SPRY4-AKT axis might act as a promising target for lung cancer therapy clinically.

tRF-Leu-CAG promotes cell proliferation and cell cycle in non-small cell lung cancer.

tRNA-derived RNA fragments (tRFs), non-coding single-stranded RNAs with 14-35 nt in length, were found to play important roles in gene regulation, even in carcinogenesis. In this study, we investigated the expression of tRF-Leu-CAG in human non-small cell lung cancer (NSCLC) and its function in the cell proliferation and cell cycle of NSCLC. The expression level of tRF-Leu-CAG was detected in NSCLC tissues, cell lines, and sera. tRF-Leu-CAG RNA levels were higher in NSCLC tumor tissues than in normal tissues, and also upregulated in NSCLC cell lines. A significant relationship was observed between stage progression and tRF-Leu-CAG in NSCLC sera. We found that in H1299 cells, inhibition of tRF-Leu-CAG suppressed cell proliferation and impeded cell cycle. AURKA was also repressed with the knockdown of tRF-Leu-CAG. Thus, our study revealed that tRF-Leu-CAG may be involved in regulating AURKA and could be a new diagnostic marker and potential therapeutic target in NSCLC.

Direct repression of the oncogene CDK4 by the tumor suppressor miR-486-5p in non-small cell lung cancer.

MicroRNAs are a class of non-coding single-stranded RNA, 20-23 nucleotide in length, which can be involved in the regulation of gene expression. Through binding with 3'-untranslated regions (3'-UTR), microRNAs can cause degradation of target mRNAs or inhibition of translation, and thus regulating the expression of genes at the post-transcriptional level. In this study, we found that miR-486-5p was significantly downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines, suggesting that miR-486-5p might function as a tumor suppressor in lung cancer. Additionally, we showed that CDK4, an oncogene that plays an important role in cell cycle G1/S phase progression, was directly targeted by miR-486-5p. Furthermore, our data reveals that knockdown of CDK4 by siRNA can inhibit cell proliferation, promote apoptosis, and impede cell-cycle progression. In epigenetics, the upstream promoter of miR-486-5p was strongly regulated by methylation in NSCLC. Collectively, our results suggest that miR-486-5p could not only inhibit NSCLC by downregulating the expression of CDK4, but also be as a promising and potent therapy in the near future.

Proteome analysis and tissue array for profiling protein markers associated with type B thymoma subclassification.

BACKGROUND: The prognostic relevance of World Health Organization (WHO) subtypes within type B thymomas is still controversial. Understanding of the molecular characteristics of the different histologic types of thymomas will provide meaningful information for diagnosis and therapeutic management in type B thymoma. METHODS: Proteins extracted from twelve type B thymoma tissue specimens (six type B1 and six type B2) were analyzed by two-dimensional electrophoresis (2-DE) coupled with MALDI-TOF-MS. Differentially expressed proteins were then assayed in sixty-nine type B thymoma tissues (including B1, B2 and B3) by tissue array analysis with immunohistochemistry staining. The relationship of their expression with clinicopathological parameters, such as tumor stage or WHO classification, was estimated by Spearman's Rank Correlation Test. RESULTS: Sixteen differentially expressed proteins between type B1 and B2 thymoma tissues were identified. The differential levels of ezrin and glutathione S-transferase pi (GSTP1) were validated using immunohistochemistry staining. A statistically significant difference was observed in the positive rate of ezrin expression between type B1 thymoma and type B3 thymoma (Z = -2.963, P < 0.01). Ezrin showed a tendency to be expressed in higher classification tumors from type B1 to B3. A statistical analysis demonstrated that type B2 and B3 tumors had significantly higher positive expression of GSTP1 than the B1 group (type B2 vs. B1: Z = -2.582, P = 0.01; type B3 vs. B1: Z = -4.012, P ≤ 0.001). The results also showed a strong correlation between GSTP1 and WHO type staging of B1 to B3 tumors (Spearman's correlation coefficient: 0.633, P ≤ 0.001). Statistical analysis showed that there was close correlation between GSTP1 and ezrin expression with the clinical stage (Spearman's correlation coefficients, ezrin: 0.481, P < 0.05; GSTP1: 0.484, P < 0.01). CONCLUSIONS: Differentially expressed proteins between type B1 and B2 thymoma tissues were analyzed by comparative proteomic analysis. The techniques of proteomic analysis and tissue array provide a potential tool for screening of key molecules in type B thymoma histological sub-classifications. The statistical analysis of ezrin and GSTP1 expression by immunohistochemistry, especially GSTP1, may be a useful approach for type B thymoma classification.

Comparative proteomic analysis of paclitaxel sensitive A549 lung adenocarcinoma cell line and its resistant counterpart A549-Taxol.

PURPOSE: Paclitaxel is used as the first-line chemotherapy for Non-Small Cell Lung Cancer (NSCLC), but acquired resistance becomes a critical problem. Several mechanisms have been proposed in paclitaxel resistance, but they are not sufficient to exhaustively explain this resistance emergence. To better investigate molecular resistance mechanisms, a comparative proteomic approach was carried out to identify differentially expressed proteins between human lung adenocarcinoma A549 cell line (paclitaxel sensitive) and A549-Taxol cell line (acquired resistant). METHODS: A paclitaxel-resistant subline (A549-Taxol) derived from the parental-sensitive cell line A549 was established by stepwise selection by paclitaxel. Total proteins in the two cell lines were separated by fluorescent differential gel electrophoresis (DIGE). Image analysis was carried out with the DeCyder 2D 6.5 software. Proteins associated with chemoresistance process were identified by matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS/MS). Some key molecules were valuated by Western blot. RESULTS: Thirty proteins were identified and grouped into eight main functional classes according to the biological processes in which they are likely to participate, i.e. signal transduction, cytoskeleton, redox reaction, energy and metabolism, and so on. Alterations of these processes might be involved in paclitaxel resistance. Most of the proteins showed mitochondrial and cytoplasm location. The up-regulation of CK8, CK18, ALDH1, CAST and ANX I in A549-Taxol cell line was verified by Western blot, in coincidence with the data obtained from proteomic analysis. CONCLUSION: For the first time, differentially expressed proteins between paclitaxel-sensitive cell line and paclitaxel-resistant one were explored by comparative proteomic approach in human lung adenocarcinoma. It may be useful for further studying of resistance mechanisms and screening of resistance biomarkers, so as to develop tailored therapeutic strategies.

DSA affinity glycoproteome of human liver tissue.

Due to the critical roles of glycoproteins in the activities of cells to tissues, mapping of liver glycoproteome may provide valuable basic information for finding disease marker proteins. In this study, Datura Stramonium Agglutinin (DSA) was chosen to enrich N-linked glycoproteins for its broader specificity with tri- or tetra-antennary complex type. DSA affinity glycoproteins' profiles of human liver tissue were generated by two-dimensional electrophoresis (2-DE) followed by glycoprotein staining based on multiplexed proteomics (MP) technology. 64+/-3 (n=3) protein spots were detected and 41 of glycoproteins were identified via peptide mass fingerprinting (PMF) using MALDI-TOF-MS/MS and annotated to IPI databases. Identified glycoproteins definitely take part in the regulation of cell cycle and metabolic processes. The detailed carbohydrate moiety of some glycoproteins might be concluded according to the literatures. The construction of DSA affinity glycoprotein database would contribute to the subsequent research.

[Analysis of differential gel electrophoresis of paclitaxol resistant and sensitive lung adenocarcinoma cells' secretome.].

BACKGROUND: Paclitaxol (PTX) resistance is one of main factors which affect the outcome of chemotherapy of lung adenocarcinoma. The aim of this study is to compare the secreted protein expression profiles between Paclitaxol (PTX) resistant and sensitive lung adenocarcinoma cells by proteomic research method, so as to provide evidence of choosing individual chemotherapy drugs in clinical treatment. METHODS: Total secreted proteins extracted from a PTX sensitive cell line A549 and a PTX resistant cell line A549-Taxol were separated by fluorscent differential gel electrophoresis (DIGE). High quality 2-DE profiles were obtained and analyzed by Decyder 6.5 analysis software to screen differentially expressed protein spots. Those spots were identified by mass spectrometry. RESULTS: 2-DE patterns of lung adenocarcinoma cells with high-resolution and reproducibility were obtained. 76 significantly differentially expressed protein spots were screened, 19 proteins were identified by mass spectrometry. The identified proteins could be classified into different catogories: metabolic enzyme, extracellular matrix (ECM) degradation enzyme, cytokine, signal transducer, cell adhesion, and so on. CONCLUSIONS: Multiple secreted proteins related to chemoresistance of A549-Taxol cells were identified in this study for the first time. The results presented here would provide clues to identify new serologic chemoresistant biomarkers of NSCLC.