A classification method based on principal components of SELDI spectra to diagnose of lung adenocarcinoma.

PURPOSE: Lung cancer is the leading cause of cancer death worldwide, but techniques for effective early diagnosis are still lacking. Proteomics technology has been applied extensively to the study of the proteins involved in carcinogenesis. In this paper, a classification method was developed based on principal components of surface-enhanced laser desorption/ionization (SELDI) spectral data. This method was applied to SELDI spectral data from 71 lung adenocarcinoma patients and 24 healthy individuals. Unlike other peak-selection-based methods, this method takes each spectrum as a unity. The aim of this paper was to demonstrate that this unity-based classification method is more robust and powerful as a method of diagnosis than peak-selection-based methods. RESULTS: The results showed that this classification method, which is based on principal components, has outstanding performance with respect to distinguishing lung adenocarcinoma patients from normal individuals. Through leaving-one-out, 19-fold, 5-fold and 2-fold cross-validation studies, we found that this classification method based on principal components completely outperforms peak-selection-based methods, such as decision tree, classification and regression tree, support vector machine, and linear discriminant analysis. CONCLUSIONS AND CLINICAL RELEVANCE: The classification method based on principal components of SELDI spectral data is a robust and powerful means of diagnosing lung adenocarcinoma. We assert that the high efficiency of this classification method renders it feasible for large-scale clinical use.

Expression of GPC3 protein and its significance in lung squamous cell carcinoma.

The purpose of this study was to investigate GPC3 gene expression in lung squamous cell carcinoma tissue and its correlation with clinical and tumor characteristics. Using RT-PCR, the presence of GPC3 gene expression was detected in cancer tissue and adjacent normal tissue in 66 cases of lung squamous cell carcinoma and positive rates were calculated. Using Western blot, changes in GPC3 protein expression were detected in lung squamous cell carcinoma and adjacent normal tissues. The percentage of tissue samples expressing GPC3 mRNA was significantly higher in lung squamous cell carcinoma than in adjacent normal tissue (P < 0.05). This percentage was also significantly higher for cases with lymph node metastasis than for those without lymph node metastasis (P < 0.05). Further, the percentage of samples expressing GPC3 mRNA was higher with lowering degrees of tumor differentiation (P < 0.05). Rates of GPC3 expression were, however, independent of patient gender, age, and tumor size (P > 0.05). The expression of GPC3 protein in lung squamous cell carcinoma was significantly higher than that in adjacent normal tissues (P < 0.05). The expression in cases with lymph node metastasis was significantly higher than in those without lymph node metastasis (P < 0.05), and GPC3 protein expression increased with lowering degrees of tumor differentiation (P < 0.05). Further investigation is warranted for the association of initiation, development, invasion, and metastasis of disease.

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.

Prognostic impact of vascular endothelial growth factor-A and E-cadherin expression in completely resected pathologic stage I non-small cell lung cancer.

OBJECTIVE: The purpose of this study was to evaluate the value of vascular endothelial growth factor-A and E-cadherin expression as well as other confirmed prognostic factors in predicting the clinical outcome after definitive surgery of pathologic stage I non-small cell lung cancer. METHODS: One hundred and eighty-five consecutive and non-selected patients who underwent definitive surgery for stage I non-small cell lung cancer in our institute were included in this study. Formalin-fixed paraffin-embedded specimens were stained for vascular endothelial growth factor-A and E-cadherin and the correlation between the staining, its clinicopathological parameters and its prognostic power were analyzed statistically. RESULTS: Of the 185 patients studied, 92 cases (49.7%) were strongly positive for vascular endothelial growth factor-A. Vascular endothelial growth factor-A expression was only related to visceral pleural involvement (P < 0.001). A total of 95 carcinomas (51.4%) were E-cadherin-negative tumors. E-cadherin expression correlated with histology (P < 0.001), tumor size (P = 0.001) and visceral pleural involvement (P < 0.001). In univariate analysis by log-rank test, gender, tumor size, lymphovascular invasion, visceral pleural involvement, vascular endothelial growth factor-A expression and E-cadherin expression were significant prognostic factors (P = 0.003, 0.042, 0.026, 0.035, 0.008 and 0.006, respectively). In multivariate analysis, gender, vascular endothelial growth factor-A and E-cadherin expression maintained its independent prognostic influence on overall survival (P = 0.013, <0.001 and 0.036, respectively). CONCLUSIONS: Expression of vascular endothelial growth factor-A is related to visceral pleural involvement, and E-cadherin expression correlates with histology, tumor size and visceral pleural involvement. Multivariate analysis confirmed gender, vascular endothelial growth factor-A and E-cadherin expression were significant predictive factors for overall survival in completely resected pathologic stage I non-small cell lung cancer.

[VEGF-C mRNA expression and its relationship with clinicopathological parameters in esophageal squamous cell carcinoma].

OBJECTIVE: To detect the expression of VEGF-C mRNA and to investigate its relationship with clinicopathological parameters in esophageal squamous cell carcinoma (ESCC). METHODS: Real-time quantitative reverse transcriptase-PCR was used to measure the level of VEGF-C mRNA in the tumor tissue and corresponding normal mucosa in ESCC patients. RESULTS: The VEGF-C mRNA expression in tumor tissue was significantly higher than that in the corresponding normal mucosa (6.30 vs. 2.81, P = 0.02), and also significantly higher in the patients with lymph node metastasis than that in those without lymph node metastasis (10.11 vs. 4.15, P = 0.04). Among the patients with metastatic lymph nodes, VEGF-C mRNA expression was 62.19 in the patients with > or = 4 metastatic lymph nodes versus 6.30 in those with < 4 (P = 0.01), and 18.98 in the patients with > or = 3 metastatic lymph node stations versus 4.92 in those with < 3 (P = 0.04). In terms of stage, VEGF-C mRNA expression was significantly higher in the stage II b + III + IV than that in the stage I + II a (9.99 vs. 3.80, P = 0.03). Logistic binary regression analysis showed that VEGF-C mRNA was an independent risk factor for lymph node metastasis in ESCC (P = 0.01). In survival analysis, 2-year survival rate was not related with VEGF-C mRNA expression (P = 0.46). It was showed by COX regression model that the number of metastatic lymph node stations was the only independent risk factor for survival (P < 0.01). CONCLUSION: The expression of VEGF-C mRNA play an important role in lymph node metastasis of human ESCC.

[Efficient generation and functional characteristics of dendritic cells from malignant pleural effusion in patients with lung cancer].

OBJECTIVE: To clarify whether functionally competent dendritic cells (DC) can be generated from malignant pleural effusion in patients with lung cancer. METHODS: Malignant effusion-associated monocytes were separated by adherence from malignant effusion-associated mononuclear cells and cultured in medium with granulocyte macrophage colony-stimulating factor (GM-CSF) plus interleukin 4 (IL-4). TNF-alpha was added for the last 24 h before culture termination. Cultured DC were identified by (1) using microscopy, scanning electron microscopy, and immunocytochemistry for the morphological features; (2) phenotypic markers; and (3) functional characteristics including a high stimulatory capacity to activate proliferation of lymphocyte in an allogeneic mixed leukocyte reaction and the ability to produce high levels of IFN-gamma. RESULTS: Cultured DC had the typical morphological features. The phenotype of DCs generated from effusion showed higher expression of CD(86) (84.6 +/- 6.1)%, HLA-DR (81.1 +/- 13.0)%, CD(40) (42.0 +/- 21.7)%, CD(1a) (20.0 +/- 9.5)% and lower expression of CD(14) (4.8 +/- 3.5)% than the control group. There was a significant difference in the stimulatory activity in allogeneic lymphocyte proliferation and the ability to produce high levels of IFN-gamma between DC derived from the malignant effusion and the control group. CONCLUSION: These findings suggest that DC can be generated from malignant pleural effusion, which might be a useful source of DC for immunotherapy.

[Implication of micrometastatic cancer cells in the peripheral blood on prognosis of non-small cell lung cancer].

OBJECTIVE: To evaluate the relationship of micrometastatic cancer cells in the blood and prognosis of patients with non-small cell lung cancer (NSCLC). METHODS: Blood samples were collected from peripheral vein perioperatively and from the pulmonary vein intraoperatively in NSCLC patients. Cancer cells were detected by flow cytometry, as described previously. The patients were followed up and analyzed statistically. RESULTS: Cancer cells in blood samples were detected in 20 of 58 patients (34.5%). Patients under 57 years of age or with stage III/IV lesions had higher positive findings than those over 57 years or with stage I/II lesions (P = 0.000 and 0.006, respectively). On the basis of 40 month follow-up data, the 2- and 3-year survival rates of patients with positive and negative results were 30.0% vs 20.0%, and 52.6% vs 50.0%, respectively. There was significant difference between the overall survival curves which favored patients with negative findings (P = 0.0291 and 0.0092, respectively). CONCLUSION: This study indicates that cancer cells can be detected in the blood perioperatively from NSCLC patients which means poor prognosis.

[Vascular endothelial growth factor inhibits dendritic cells from patients with non-small cell lung carcinoma].

OBJECTIVE: To detect the effect of vascular endothelial growth factor (VEGF) on dendritic cells (DC) in patients with non-small cell lung cancer (NSCLC). METHODS: The measurement of DC in the peripheral blood was performed by a novel flow cytometric assay in 85 patients with NSCLC and 14 healthy volunteers. Enzyme-linked immunosorbent assay (ELISA) was used to measure the concentration of VEGF(165) in the plasma. CD(14)(+) peripheral blood mononuclear cells (PBMC) were cultured to obtain DC in vitro with cytokines. VEGF(165) was added to evaluate its effect on DC differentiation and survival. The phenotypes and apoptosis of cultured cells were detected by flow cytometry. RESULTS: In comparison with healthy volunteers, the level of VEGF(165) was significantly increased (P < 0.05), while that of DC was significantly decreased (P < 0.01) in patients with NSCLC. No significant correlation was noted between the concentration of VEGF(165) and age, gender, differentiation and histological types in patients with NSCLC, neither was found in the level of DC (P > 0.05). The concentration of VEGF(165) was closely associated with TNM stage and distal metastasis (P < 0.05), while no correlation was found between the concentration of VEGF(165) and lymph node metastasis (P > 0.05). Significant correlations were noted between the level of DC in patients with NSCLC and TNM stage, lymph node metastasis and distal metastasis (P < 0.05). There was a negative correlation between the concentration of VEGF(165) and the level of DC (P < 0.05). Patients with abnormally elevated VEGF(165) showed significantly fewer DC. Cells cultured in vitro in the presence of VEGF(165) exhibited higher expression of CD(+)(14)(P = 0.000) and increased ratio of apoptic cells (P < 0.01), but decreased expression of CD(40), CD(86) and HLA-DR (P < 0.01), as compared to cells cultured without VEGF(165). CONCLUSIONS: The level of DC and the concentration of VEGF in the peripheral blood can reflect the malignancy of NSCLC. NSCLC can over-express VEGF to inhibit DC differentiation and maturation to evade host immune surveillance.