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Tumorigenesis is closely and highly associated with developmental biology. The present study aimed to discover and identify marker proteins strongly associated with the occurrence and development of non‑small cell lung cancer (NSCLC) in humans and to provide new ideas for investigating lung cancer markers by combining biological analyses of embryonic development. We established primary cultures for samples of tumor and control tissues from 9 patients with NSCLC and collected conditioned medium (CM). Subsequently, we used liquid chromatography and linear ion trap (LTQ) mass spectrometry to isolate and identify proteins in CM samples. Data mining of free proteins was conducted using the analogous analysis strategy in systems biology to obtain important lung cancer‑associated proteins (plasma markers). Proteins with significant plasma enrichment in lung cancer patients were detected via enzyme‑linked immunosorbent assay (ELISA). We identified 987 high‑confidence proteins and established a primary database of free proteins associated with lung cancer. Furthermore, 511 high‑confidence proteins were present in CM from primary tissue cultures from at least 2 of the 9 examined cases of lung cancer. Analysis using Gene Set Enrichment Analysis (GSEA) software revealed significant enrichment for 197 proteins from the CM of lung cancer samples in maternal‑placental interface expression profiles for a mid‑term placenta with strong invasiveness relative to RNA expression profiles for a human full‑term placenta after delivery. ELISA results demonstrated that hypoxanthine phosphoribosyltransferase 1 (HPRT1) was associated with worse rates of disease‑free survival (DFS) and overall survival (OS). The biological behaviors of embryonic implantation are similar to those of tumor invasion and metastasis, and the information obtained regarding developmental biology could facilitate the interpretation of tumor invasion and metastasis. Therefore, similar biological behaviors combined with analyses at different molecular levels from the perspective of systems biology will provide new ideas for tumor research.

This study aimed to assess the diagnostic value of the latent transforming growth factor-beta binding protein-1 (LTBP-1) in distinguishing hepatocellular carcinoma (HCC) from patients with hepatitis or liver cirrhosis. The protein levels of LTBP-1 or AFP in circulating plasma were measured by enzyme-linked immunosorbent assay (ELISA) or chemiluminescence in four cohorts: HCC (n = 167), liver cirrhosis (n = 50), chronic hepatitis B (CHB, n = 50), and healthy individuals (n = 104). Receiver operating characteristics (ROC) curves and area under the curves (AUC) of the proteins were calculated. Results showed that plasma levels of LTBP-1 were significantly higher in HCC patients than those in other three groups. LTBP-1 showed a better diagnostic performance (AUC = 0.74, 95% CI: 0.67-0.80) in distinguishing HCC from the CHB or cirrhosis patients, compared to AFP (AUC = 0.59, 95% CI: 0.52-0.65). In the early-stage HCCs investigated, diagnostic performance of LTBP-1 (AUC = 0.77, 95% CI: 0.70-0.84) remained better than that of AFP (AUC = 0.61, 95% CI: 0.52-0.69). Combination of LTBP-1 and AFP showed increased diagnostic efficiency than any of the two proteins performed alone, for both all HCC (AUC = 0.78, 95% CI: 0.72-0.83) and early-stage HCC (AUC = 0.80, 95% CI: 0.74-0.87). These findings proposed that LTBP-1 may be a promising biomarker for distinguishing HCC from the CHB or liver cirrhosis patients, especially for the early-stage HCC.

Long-term exposure to airborne PM2.5 is associated with increased lung cancer risk but the underlying mechanism remains unclear. We characterized global microRNA and mRNA expression in human bronchial epithelial cells exposed to PM2.5 organic extract and integrally analyzed microRNA-mRNA interactions. Foci formation and xenograft tumorigenesis in mice with NIH3T3 cells expressing genes targeted by microRNAs were performed to explore the oncogenic potential of these genes. We also detected plasma levels of candidate microRNAs in subjects exposed to different levels of air PM2.5 and examined the aberrant expression of genes targeted by these microRNAs in human lung cancer. Under our experimental conditions, treatment of cells with PM2.5 extract resulted in downregulation of 138 microRNAs and aberrant expression of 13 mRNAs (11 upregulation and 2 downregulation). In silico and biochemical analyses suggested SLC30A1, SERPINB2 and AKR1C1, among the upregulated genes, as target for miR-182 and miR-185, respectively. Ectopic expression of each of these genes significantly enhanced foci formation in NIH3T3 cells. Following subcutaneous injection of these cells into nude mice, fibrosarcoma were formed from SLC30A1- or SERPINB2-expressing cells. Reduced plasma levels of miR-182 were detected in subjects exposed to high level of PM2.5 than in those exposed to low level of PM2.5 (P = 0.043). Similar results were seen for miR-185 although the difference was not statistically significant (P = 0.328). Increased expressions of SLC30A1, SERPINB2 and AKR1C1 were detected in human lung cancer. These results suggest that modulation of miR-182 and miR-185 and their target genes may contribute to lung carcinogenesis attributable to PM2.5 exposure.

Objective: To evaluate septin-9 and clusterin protein levels in the peripheral blood samples from epithelial ovarian cancer patients, and explore its clinical significance., Methods: Clinical data of 200 patients in Cancer Hospital, Chinese Academy of Medical Sciences from Jan. 29, 2008 to Feb. 1, 2010 were collected. The peripheral blood samples were obtained from 137 epithelial ovarian cancer patients, 12 borderline ovarian tumor patients, 10 benign ovarian tumor patients, 41 benign pelvic lesion patients and 58 healthy women. The septin-9 and clusterin protein levels in the plasma were measured by double antibody sandwich ELISA or ELISA. The clinical significance of clusterin and septin-9 in plasma was analyzed. The diagnostic efficacy of septin-9 and clusterin protein in the detection of ovarian cancer was evaluated by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve., Results: Double antibody sandwich ELISA showed: the mean levels of plasma septin-9 in epithelial ovarian cancer patients or benign pelvic lesion patients were significantly higher than that in healthy women detedted by double antibody sandwich ELISA (P < 0.01). The mean levels of plasma septin-9 in epithelial ovarian carcinoma patients with tumor family history or distance metastasis were significantly higher than those patients without (P < 0.05). While the expression level of septin-9 protein in peripheral blood of ovarian cancer patients was not related to the patient age, pathologic stage, pathologic differentiation, smoking history, treatment history (including surgery, radiotherapy and chemotherapy) and lymph node metastasis (all P > 0.05). ELISA showed: the mean level of plasma clusterin in epithelial ovarian cancer patients was significantly higher than that in healthy women deteded by ELISA (P = 0.021). The expression level of clusterin protein in peripheral blood of ovarian cancer patients was not related to the above clinical pathological parameters (all P > 0.05). To distinguish between ovarian cancer patients and healthy women by septin-9 protein expression level in plasma, when AUC was 0.712 and cut off was 0.28, the sensitivity of detection ovarian cancer by septin-9 protein expression was 82.5%, and the specificity was 50.0%. To distinguish between ovarian cancer patients and healthy women by clusterin protein expression level in plasma, when AUC was 0.636 and cut off was 87.96 pg/L, the sensitivity of detection ovarian cancer by clusterin protein expression was 71.5%, and the specificity was 41.4%., Conclusions: The expression of septin-9 and clusterin protein in peripheral blood of ovarian cancer patients is increased, especially the expression level of septin-9 protein with related to the distant metastasis. The study results shown that the detection of septin-9 and clusterin in plasma has a certain diagnosis value in ovarian cancer, which may be a potential markers for ovarian cancer.

Objective: Effective biomarkers for early detection of ovarian cancer are needed. Our study previously showed that basement membrane protein, nidogen-1 plasma level was significantly increased in ovarian cancer patients. This study aimed to examine the plasma levels of nidogen-1 in a large patient population to evaluate its effectiveness in ovarian serous carcinoma and expression in tumor tissues., Methods: The concentration of nidogen-1 in circulating plasma specimens of 265 ovarian serous cancer patients and 98 healthy individuals were assayed by enzyme linked immunosorbent assay. The medical records of 265 ovarian serous cancer cases were reviewed retrospectively. The expression status of nidogen-1 in tumor tissues of 44 ovarian serous carcinoma patients was examined by immunohistochemical analysis. For statistical analysis, we used the Mann-Whitney U test, Fisher's exact test and receiver operating characteristic., Results: Protein levels of nidogen-1 were considerably raised in the plasma from ovarian serous cancer patients compared with those in healthy controls (P < 0.001), especially elevated in patients with advanced stage and those received neoadjuvant chemotherapy followed by interval debulking surgery. However, it was irrelevant to the grade, chemotherapy sensitivity or residual tumor of the ovarian serous carcinoma cases investigated (P > 0.05). Receiver operating characteristic curve analysis for nidogen-1 showed that it could discriminate patients with ovarian serous carcinomas from healthy controls [areas under the curve (AUC): 0. 65, 95%CI, 0.59-0.71], but CA125 was superior (AUC: 0. 98, 95%CI, 0.96-0.99). The immunohistochemical staining result showed that nidogen-1 protein was localized both in the cancer cell cytoplasm and intercellular substance, mainly expressed in extracellular matrix of ovarian serous carcinoma tissues (the positive rate was 77.3%)., Conclusions: Our study suggests that plasma nidogen-1 may be used as a diagnostic biomarker for ovarian serous carcinoma and can reflect the tumor burden., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Objective: This study was aimed to create a large-scale laryngeal cancer relevant secretory/releasing protein database and further discover candidate biomarkers., Methods: Primary tissue cultures were established using tumor tissues and matched normal mucosal tissues collected from four laryngeal cancer patients. Serum-free conditioned medium (CM) samples were collected. These samples were then sequentially processed by SDS-PAGE separation, trypsin digestion, and LC-MS/MS analysis. The candidates in the database were validated by ELISA using plasma samples from laryngeal cancer patients, benign patients, and healthy individuals., Results: Combining MS data from the tumor tissues and normal tissues, 982 proteins were identified in total; extracellular proteins and cell surface proteins accounted for 15.0% and 4.3%, respectively. According to stringent criteria, 49 proteins were selected as candidates worthy of further validation. Of these, human tissue kallikrein 6 (KLK6) was verified. The level of KLK6 was significantly increased in the plasma samples from the cancer cohort compared to the benign and healthy cohorts and moreover showed a slight decrease in the postoperative plasma samples in comparison to the preoperative plasma samples., Conclusions: This laryngeal cancer-derived protein database provides a promising repository of candidate blood biomarkers for laryngeal cancer. The diagnostic potential of KLK6 deserves further investigation.

Cancer/testis antigens (CTAs) are highly immunogenic in many tumors, especially in non-small cell lung cancer (NSCLC). A low-density protein microarray, which consisted of 72 CTAs and six non-CTAs, was used to screen for lung cancer-related autoantibodies. The CTA panel of NY-ESO-1, XAGE-1, ADAM29 and MAGEC1, had sensitivity and specificity values of 33% and 96%, respectively. When examined in a test set, this panel of markers had sensitivity and specificity values of 36% and 89%, respectively. This array of markers preferentially detected NSCLC, but did not detect breast cancer, and non-cancer lung disease., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Ovarian cancer is the most lethal gynecological malignancy worldwide, and early detection of this disease using serum or plasma biomarkers may improve its clinical outcome. In the present study, a large scale protein database derived from ovarian cancer was created to enable tumor marker discovery. First, primary organ cultures were established with the tumor tissues and corresponding normal tissues obtained from six ovarian cancer patients, and the serum-free conditioned medium (CM) samples were collected for proteomic analysis. The total proteins from the CM sample were separated by SDS-PAGE, digested with trypsin and then analyzed by LC-MS/MS. Combining data from the tumor tissues and the normal tissues, 1129 proteins were identified in total, of which those categorized as "extracellular proteins" and "plasma membrane proteins" accounted for 21.4% and 16.9%, respectively. For validation, three secretory proteins (NID1, TIMP2, and VCAN) involved in "organ development"-associated subnetwork, showed significant differences between their levels in the circulating plasma samples from ovarian cancer patients and healthy women. In conclusion, this ovarian cancer-derived protein database provides a credible repertoire of potential biomarkers in blood for this malignant disease, and deserves mining further., (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Aims: Lung cancer patients within the pN0 category have a significantly different outcome. The aim of this study was to develop a mathematical model to assist in predicting the prognosis of pN0 lung squamous cell carcinoma (SCC)., Methods and Results: Twenty-three proteins were examined by immunohistochemical (IHC) analysis on primary tumour tissues from 319 lung SCC patients. In a training group, using IHC data, a recursive partitioning decision tree (RP-DT) was used to build a model for estimating the risk for lymphatic metastasis. This model was then validated in a test cohort. Of 23 proteins, 8 (matrix metallopeptidase 1, metalloproteinase inhibitor 1, Ras GTPase-activating-like protein IQGAP1, targeting protein for Xklp2, urokinase-type plasminogen activator, cathepsin D, fascin, polymeric immunoglobulin receptor/secretory component) were selected, and generated a tree model in a training group of 255 patients to classify them as at high or low risk of lymphatic invasion, with accuracy of 78.0% (compared to histopathological diagnosis), sensitivity of 83.0% and specificity of 70.3%. When the tree model was applied to the test group, the accuracy, sensitivity and specificity were 76.6%, 76.0% and 76.9%, respectively. The performance of this mathematical model was substantiated further in 34 'problematic' stage I/pN0 patients by survival analysis., Conclusions: The RP-DT model, constructed with eight protein markers for estimating lymphatic metastasis risk in pN0 lung SCC, is clinically feasible and practical, using IHC data from the primary tumour., (© 2011 Blackwell Publishing Limited.)

Background and Objective: proper tumor markers are useful to diagnosis, prognosis and treatment for lung cancer. The aim of this study is to examine the levels of alpha-enolase (ENO1) protein in the tumor tissues and peripheral plasma samples obtained from non-small cell lung cancer (NSCLC) patients, and evaluate its potential clinical significance., Methods: the ENO1 protein levels in the tumor tissues and corresponding normal tissues from 16 cases of lung squamous cell carcinoma were analyzed by Western blot. The ENO1 protein levels in the plasma samples from 42 healthy individuals, 34 patients with lung benign disease and 84 patients with NSCLC were measured by double antibody sandwich enzyme-linked immunosorbent assay., Results: for 87.5% (14/16) of the patients with lung squamous cell carcinoma, the ENO1 protein level in the tumor tissues was higher than that in the corresponding normal lung tissues. The ENO1 protein level in the plasma of NSCLC patients was significantly higher than that in the plasma of healthy individuals (P=0.031) and patients with lung benign disease (P=0.019). Furthermore, the ENO1 protein level was significantly higher in the plasma of patients with lung adenocarcinoma than that of patients with lung squamous cell carcinoma., Conclusions: the elevated levels of ENO1 protein in the tumor tissues and the plasma samples from NSCLC patients indicate ENO1 may be a candidate biomarker of lung cancer.

Matrix metalloproteinase-1 (MMP-1) participates in a variety of physiological and pathological processes. We previously found that MMP-1 was one of the lung cancer-related proteins detectable in peripheral blood. To validate our preliminary observations and explore the clinical significance of MMP-1 for lung cancer further, we carried out the present study. The concentrations of MMP-1 in circulating plasma specimens of 170 lung cancer patients and 70 healthy individuals were measured by an enzyme-linked immunosorbance assay. The expression status of the MMP-1 in archival tissue samples from 122 lung cancer patients was examined by immunohistochemical analysis. The correlation between the MMP-1 levels and prognosis of the lung cancer patients was then assessed statistically. Protein levels of MMP-1 were considerably raised in the plasma from lung cancer patients relative to those in healthy controls. The high plasma MMP-1 levels were associated with advanced-stage of the disease and significantly lower overall survival rate of the patients. Coincidently, MMP-1 protein extraordinarily overexpressed in the tumour tissues of lung cancer; and the up-regulated MMP-1 was associated with the progression (including tumour size, staging and lymphatic invasion), especially with decreased survival rate of the patients. Statistic analysis revealed that MMP-1 protein levels had an independent influence on survival. MMP-1 levels were elevated in both tumour tissue and blood; the latter may serve as an independent predictor for survival of lung cancer patients. MMP-1 protein levels in plasma/serum thus represent a potential and clinically relevant biomarker for the prognosis of patients with lung cancers., (Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.)

To identify differentially expressed genes in lung squamous cell carcinomas (SCCs), the suppression subtractive hybridization method (SSH) was performed comparing six lung tumour tissues and 10 morphologically normal bronchial epithelial tissues. A cDNA library consisting of 220 upregulated genes in tumour tissue was established and named as LSCC (lung squamous cell carcinoma). Of them, six were tested using semi-quantitative reverse transcription-PCR on 27 pairs of tumour tissue and normal lung tissue. Differential expression was confirmed in five of these six genes, including IGFBP5, SQLE, RAP2B, CLDN1, and TBL1XR1. The elevated mRNA expression of RAP2B, CLDN1 and TBL1XR1, three genes located on chromosome 3q, were further validated in 64.3% (18/28), 82.1% (23/28), and 75.0% (21/28) of lung SCC tumour tissues, respectively, by quantitative real-time reverse transcription-PCR analysis. Moreover, western blot analysis showed that the protein expression of TBL1XR1 was also upregulated in 53.3% (8/15) of lung SCC tumour samples, as well as in five lung cancer cell lines and in one human immortalized bronchial epithelial cell line. All the initial characteristics of these genes were first reported in the lung SCCs. The differentially expressed genes reported in this study will provide a valuable resource for understanding the pathogenesis of lung SCCs and for discovery of novel diagnostic or therapeutic targets.

Aim: To study the expression of Fhit protein in lung cancers and its potential relevance in the diagnosis and prognosis of lung cancers., Methods: Tissue microarrays (TMA) and Immunohistochemistry (IHC) were performed in 321 cases of lung cancers. Fhit protein was tested by the S-P immunohistochemistry method upon tissue microarrays., Results: In our TMA blocks comprising 321 cases of lung cancer, there were 253 (78.8 %) cases valid for Fhit protein assessment. Total loss or marked reduction of Fhit expression (-, +) were seen in 170 cases (67.1 %). Fhit protein loss in NSCLCs (non-small cell lung carcinoma was significantly lower than in SCLCs (small cell lung cancers) (p < 0.05), in most squamous cell carcinomas (85 out of 105, 81.0 %), and in a smaller portion of adenocarcinomas (53 out of 109, 48.6 %; p < 0.05). The loss or marked reduction of Fhit expression was more common in tumours occurring in smokers and male patients (133 out of 191, 69.6 %; 135 out of 189,71.4 %) as compared to nonsmokers and female patients (29 out of 62, 46.8 %; p < 0.005 and 29 out of 64, 45.3 %; p < 0.005). However, the expression of Fhit protein was not associated with histopathologic grading, clinical staging, lymph node metastasis or survival time., Conclusions: Our studies showed that the loss or reduced expression of Fhit, a tumour suppressor gene is a frequent occurrence in lung cancers, with variations amongst different histological subtypes. The loss or marked reduction of Fhit expression was more frequent in smokers. This study showed that tissue microarrays can be used efficiently for evaluation of the expression of certain tumor markers.

Suppression subtractive hybridization (SSH) was applied to identify differentially expressed genes in the SV40LT immortalized human bronchial epithelial cell line Y-BE, with normal human bronchial epithelial cells (HBEC) as a control. Two cDNA libraries of up- and downregulated genes were generated, comprising 218 known genes and 131 unknown genes in total. The expression of 22 clones from the 2 libraries was investigated by Northern blot analysis, and 86.4% (19/22) of them showed differential expression between Y-BE cells and HBEC. Although the Y-BE cells are nontumorigenic in nude mice, Comparative genomic hybridization (CGH) detected some DNA imbalances in Y-BE cells that were similar to lung cancer cells. Our data demonstrate that the studied cell line Y-BE and SSH is a reliable approach for identifying new genes that are associated with immortalization and early tumor development that may help to understand the pathogenesis of lung cancer., (Copyright 2002 Wiley-Liss, Inc.)