血清蛋白质指纹图谱诊断早期胃癌临床意义

目的：应用SELDI蛋白质芯片检测胃癌患者血清蛋白质指纹图谱,筛选候选肿瘤标志物以建立诊断模型。方法：表面加强激光解吸电离-飞行时间质谱（SELDI-TOF-MS）技术及其配套蛋白质芯片检测34例胃癌患者（Ⅰ／Ⅱ期12例与Ⅲ／Ⅳ期22例）和30例健康人的血清蛋白质组图谱,运用判别分析处理数据筛选标志物并建立诊断模型。结果：2046m／z、1179m／z、1817m／z、1752m／z和1588m／z等5个蛋白质峰组合所构建的诊断模型能达到鉴别胃癌患者和健康人的最佳诊断效果,特异度94．1％（32／34）,灵敏度93．3％（28／30）。单个4665m／z蛋白质峰诊断模型可达到鉴别Ⅰ／Ⅱ期与Ⅲ／Ⅳ期胃癌效果,其特异度91．6％（11／12）,灵敏度95．4％（21／22）。结论：该方法在胃癌的诊断尤其是早期诊断方面具有一定价值,值得进一步研究。     

Diagnostic application of serum proteomic patterns in gastric cancer patients by ProteinChip surface-enhanced laser desorption/ionization time-of-flight mass spectrometry

Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) is one of thecurrently used techniques to identify biomarkers for cancers. This study was planned to establish a system to accurately distinguish gastric cancer patients by using SELDI-TOF-MS. A total of 100 serum samples obtained from 60 individuals with gastric cancer and 40 healthy individuals were screened. Protein expression profiles were expressed on CM10 ProteinChip arrays and analyzed. Peak intensities were analyzed with the Biomarker Wizard software to identify peaks showing significantly different intensities between normal and cancer groups. Classification analysis and construction of decision trees were done with the Biomarker Pattern software 5.0. Seventeen protein peaks showed significant differences between the two groups. The decision tree which gave the highest discrimination included four peaks at mass 5,919, 8,583, 10,286, and 13,758 as splitters. The sensitivity and specificity for classification of the decision tree were 96.7% (58/60) and 97.5% (39/40), respectively. When the protein biomarker pattern was tested on a blinded test set, it yielded a sensitivity of 93.3% (28/30) and a specificity of 90% (18/20). These results suggest that serum protein profiling by the SELDI system may distinguish gastric cancer patients from healthy controls with relatively high sensitivity and specificity.     

Early diagnosis of lung cancer by detection of tumor liberated protein

Tumor liberated protein (TLP) is a protein that can be used to reveal the early development of a tumor. Besides being formed in the tumor, TLP is released in the blood when a patient starts producing cancer cells, which in turn enables the physician to intervene at a stage when the cancer is operable. To date, the available studies of tumor markers in lung cancer patients are CEA, NSE, TPA, Chromogranine, CA125, CA19-9, and Cyfra 21-1. The sensitivity and specificity for serum markers ranges between 50 and 90%, depending on the study and the clinical samples analyzed. Most of these markers show an increased rate of positivity as the stage advances. There are very limited data on TLP to draw any firm conclusion regarding the diagnostic value of this marker. TLP has been detected in 53.1% of non-small cell lung cancer (NSCLC) patients (N = 534) with 75% being positive in the early stage (stage I) and dropping to 45% in the late stage (stage IV). However, 7.6% blood donor sera and 17.4% chronic lung disease sera have also tested positive. In a confirmation study, the specificity was 89.94% and the sensibility was 63.63% from stage III to IV NSCLC patients. In an initial study of TLP as a marker for early detection in stage I, NSCLC patients showed a sensitivity of 66.7% and a specificity of 80% for TLP compared to a sensitivity of 33.3% for CA19-9, 11.1% for Cyfra 21-1 and CA125, and 0% for CEA; the specificity for all four of the latter markers was 100%. Using immunohistochemical analysis with peroxidase anti-peroxidase (PAP), we observed that NSCLC cells were positive; we used the specific rabbit antiserum to TLP, which turned out negative in the presence of 1 mg/ml of the synthetized peptide. The pre-serum was also negative. The same reactivity was found early in the modified epithelial cells of interstitial lung fibrosis and might be a predictive marker of cell transformation. The site of the peroxidase positivity was cytoplasmic, of diffuse and/or granular type.     

Irisin and Carcinoembryonic Antigen (CEA) as Potential Diagnostic Biomarkers in Gastric and Colorectal Cancers

Background:Carcinoembryonic antigen (CEA) is a common gastrointestinal tumor biomarker. Irisin is adipo-myokines that has been suggested to have a potential role in cancer development. However, limited studies test irisin as biomarker in gastric and colorectal cancers. Therefore, this study aims to investigate whether CEA and irisin could be a potential diagnostic biomarker in gastric and colorectal cancer.Methods:A case-control study consists of 90 subjects, 21 gastric cancer patients, 49 colorectal cancer patients and 20 control. Serum CEA was detected by fluorescence immunoassay (FIA) kit. Serum irisin was determined by enzyme-linked immunosorbent assay (ELISA) kit.Results:Serum CEA increases significantly and serum irisin decreases significantly in gastric and colorectal cancer patients. According to Receiver Operating Characteristic (ROC) curve analysis, in gastric cancer, the area under curve of CEA is 1.00 (95% CI, 1.000-1.000, p< 0.0001). The diagnostic cut-off of CEA is< 3.08 ng/ml with %100 sensitivity and 100% specificity. The area under curve of irisin is 0.94 (95% CI, 0.8177-1.000, p< 0.0001). The cut-off of irisin is> 30.2 ng/ml with %90 sensitivity and 100%, specificity. In colorectal cancer, the area under curve of CEA is 0.99 (95% CI, 0.9866-1.000, p< 0.0001) and the diagnostic value< 2.6 ng/ml with %98 sensitivity and %100 specificity. The area under curve of irisin is 0.96 (95% CI, 0.9155-1.000, p< 0.0001). The diagnostic cut-off of irisin is> 41.9 ng/ml with 88.1sensitivity and 90.5 specificity.Conclusion:CEA and irisin could be powerful potential diagnostic biomarkers which would be use for early detection of gastric and colorectal cancers.Key Words: Biomarker, Carcinoembryonic antigen (CEA), Colorectal cancer, Gastric cancer, Irisin     

Classification of HER2/neu status in gastric cancer using a breast-cancer derived proteome classifier

HER2-testing in breast and gastric cancers is mandatory for the treatment with trastuzumab. We hypothesized that imaging mass spectrometry (IMS) of breast cancers may be useful for generating a classifier that may determine HER2-status in other cancer entities irrespective of primary tumor site. A total of 107 breast (n = 48) and gastric (n = 59) cryo tissue samples was analyzed by IMS (HER2 was present in 29 cases). The obtained proteomic profiles were used to create HER2 prediction models using different classification algorithms. A breast cancer proteome derived classifier, with HER2 present in 15 cases, correctly predicted HER2-status in gastric cancers with a sensitivity of 65% and a specificity of 92%. To create a universal classifier for HER2-status, breast and nonbreast cancer samples were combined, which increased sensitivity to 78%, and specificity was 88%. Our proof of principle study provides evidence that HER2-status can be identified on a proteomic level across different cancer types suggesting that HER2 overexpression may constitute a unique molecular event independent of the tumor site. Furthermore, these results indicate that IMS may be useful for the determination of potential drugable targets, as it offers a quicker, cheaper, and more objective analysis than the standard HER2-testing procedures immunohistochemistry and fluorescence in situ hybridization.     

Development of multiplexed bead-based immunoassays for the detection of early stage ovarian cancer using a combination of serum biomarkers

CA125 as a biomarker of ovarian cancer is ineffective for the general population. The aim of this study was to evaluate multiplexed bead-based immunoassay of multiple ovarian cancer-associated biomarkers such as transthyretin and apolipoprotein A1, together with CA125, to improve the identification and evaluation of prognosis of ovarian cancer. We measured the serum levels of CA125, transthyretin, and apolipoprotein A1 from the serum of 61 healthy individuals, 84 patients with benign ovarian disease, and 118 patients with ovarian cancer using a multiplex liquid assay system, Luminex 100. The results were then analyzed according to healthy and/or benign versus ovarian cancer subjects. When CA125 was combined with the other biomarkers, the overall sensitivity and specificity were significantly improved in the ROC curve, which showed 95% and 97% sensitivity and specificity, respectively. At 95% specificity for all stages the sensitivity increased to 95.5% compared to 67% for CA125 alone. For stage I+II, the sensitivity increased from 30% for CA125 alone to 93.9%. For stage III+IV, the corresponding values were 96.5% and 91.6%, respectively. Also, the three biomarkers were sufficient for maximum separation between noncancer (healthy plus benign group) and stage I+II or all stages (I-IV) of disease. The new combination of transthyretin, and apolipoprotein A1 with CA125 improved both the sensitivity and the specificity of ovarian cancer diagnosis compared with those of individual biomarkers. These findings suggest the benefit of the combination of these markers for the diagnosis of ovarian cancer.     

Scope and limitations of MALDI-TOF MS blood serum peptide profiling in cancer diagnostics

Serum samples (33 healthy women, 34 ovarian cancer, 28 colorectal cancer, 34 syphilis patients and 136 patients with various benign gynecological diseases) were analyzed by MALDI-TOF MS peptide profiling and respective predictive models were generated by genetic and supervised neural network algorithms. Classification models for pathology versus healthy control showed up to 100% sensitivity and specificity for all target diseases. However, the specificity dropped to unsatisfactory 25–40% in case of target versus nontarget disease diagnostics. Expansion of the control group to an artificial “nominal control” group by adding profiles of benign gynecological diseases considerably improved specificity of the models distinguishing ovarian cancer from healthy control and benign gynecological diseases. The suggested version of MALDI-TOF MS profiling of sera could be applied to differentiate between cancers and benign neoplasms of the same localization which is a challenging task for classical methods. To increase the specificity of diagnostic methods based on peptidome analysis of blood samples, it is necessary to identify sets of concrete peptide structures which qualitatively or quantitatively differ among patients with different diseases.     

Correlation between tumor burden and anticomplementary activity in sera from cancer patients

Summary A total of 739 sera from cancer patients, noncancer patients and normal donors were analyzed for anticomplementary (AC) activity by the complement consumption method. The results were correlated with clinical stage and tumor burden. The incidence of AC activity in cancer and noncancer patients' sera was 53% (233/439) and 67% (100/150), respectively, as against 14% (20/140) in normal donors' sera. Among cancer patients, this incidence was lowest (42%) for melanoma sera and highest (65%) for lung carcinoma sera. With the exception of sarcoma sera, the incidence of AC activity did not differ significantly with clinical Stages I, II, or III. Sera from Stages II and III sarcoma patients had a significantly higher incidence of AC activity (73% and 63%, respectively) than Stage I (38%). There appeared to be a higher incidence of AC activity in sera of cancer patients with 1–100 g tumor burden than in those from patients with tumors greater than 100 g or less than 1 g. Follow-up of cancer patients with no evidence of disease or minimal tumor burden revealed that 42% (18/43) whose sera were AC-positive had tumor recurrence within 3 months and 90% (57/63) whose sera were AC-negative had no detectable tumor recurrence up to at least 6 months after the serum analysis.     

Screening of Prostate Cancer by Analyzing Trace Elements in Hair and Chemometrics

Prostate cancer is the most common non-cutaneous malignancy and second leading cause of cancer mortality in men. The principle goal of this study was explore the feasibility of applying boosting coupled with trace element analysis of hair, for accurately distinguishing prostate cancer from healthy person. A total of 113 subjects containing 55 healthy men and 58 prostate cancers were collected. Based on a special index of variable importance and a forward selection scheme, only nine elements (i.e., Zn, Cr, Mg, Ca, Al, P, Cd, Fe, and Mo) were picked out from 20 candidate elements for modeling the relationship. As a result, an ensemble classifier consisting of only eight decision stumps achieved an overall accuracy of 98.2%, a sensitivity of 100%, and a specificity of 96.4% on the independent test set while all subjects on the training set are classified correctly. It seems that integrating boosting and element analysis of hair can serve as a valuable tool of diagnosing prostate cancer in practice.     

Production and standardization of Paracoccidioides brasiliensis, Histoplasma capsulatum and Aspergillus fumigatus antigens to be used in immunodiagnosis. Comparison between immunodiffusion and immunoelectrophoresis

Soluble antigens (Ag) from Paracoccidioides brasiliensis, Histoplasma capsulatum and Aspergillus fumigatus were prepared and standardized by double immunodiffusion (DID) and immunoelectroosmophoresis (IEOP). No difference in sensitivity was observed between the two techniques; 100% of standard patient sera were positive with P. brasiliensis and A. fumigatus Ag and 83.3% were positive with H. capsulatum Ag. The specificity of the tests was verified testing 96 sera from patients with paracoccidioidomycosis, histoplasmosis, systemic candidiasis, sporotrichosis, tuberculosis, lung cancer, visceral or cutaneous leishmaniasis and 18 sera from healthy individuals. All the three antigens were 100% specific with the DID (using the identification pattern indicated by the confluence of test serum with standard serum precipitin lines as a positive criterium). However in the IEOP, the specificity varied with each Ag. Positive reactions with P. brasiliensis Ag were observed in 16.7% of histoplasmosis sera and in 10% of cutaneous leishmaniasis sera. On the other hand 31.8% of paracoccidioidomycosis and 10% of cutaneous leishmaniasis sera reacted with H. capsulatum Ag. The high sensitivity and specificity of the DID test, its easy reproducibility and low cost, led us to consider it highly appropriate as a routine procedure for the screening of patients with respiratory infections.     

Protein microarray signature of autoantibody biomarkers for the early detection of breast cancer

Cancer patients spontaneously generate autoantibodies (AAb) to tumor-derived proteins. To detect AAb, we have probed novel high-density custom protein microarrays (NAPPA) expressing 4988 candidate tumor antigens with sera from patients with early stage breast cancer (IBC), and bound IgG was measured. We used a three-phase serial screening approach. First, a prescreen was performed to eliminate uninformative antigens. Sera from stage I-III IBC (n = 53) and healthy women (n = 53) were screened for AAb to all 4988 protein antigens. Antigens were selected if the 95th percentile of signal of cases and controls were significantly different (p < 0.05) and if the number of cases with signals above the 95th percentile of controls was significant (p < 0.05). These 761 antigens were screened using an independent set of IBC sera (n = 51) and sera from women with benign breast disease (BBD) (n = 39). From these, 119 antigens had a partial area under the ROC curve (p < 0.05), with sensitivities ranging from 9-40% at >91% specificity. Twenty-eight of these antigens were confirmed using an independent serum cohort (n = 51 cases/38 controls, p < 0.05). Using all 28 AAb, a classifier was identified with a sensitivity of 80.8% and a specificity of 61.6% (AUC = 0.756). These are potential biomarkers for the early detection of breast cancer.     

Serum proteomic profiling for the early diagnosis of colorectal cancer

No ideal serum biomarker currently exists for the early diagnosis of colorectal cancer (CRC). Magnetic bead‐based fractionation coupled with MALDI‐TOF MS was used to screen serum samples from CRC patients, healthy controls, and other cancer patients. A diagnostic model with five proteomic features (m/z 1778.97, 1866.16, 1934.65, 2022.46, and 4588.53) was generated using Fisher algorithm with best performance. The Fisher‐based model could discriminate CRC patients from the controls with 100% (46/46) sensitivity and 100% (35/35) specificity in the training set, 95.6% (43/45) sensitivity and 83.3% (35/42) specificity in the test set. We further validated the model with 94.4% (254/269) sensitivity and 75.5% (83/110) specificity in the external independent group. In other cancers group, the Fisher‐based model classified 25 of 46 samples (54.3%) as positive and the other 21 as negative. With FT‐ICR‐MS, the proteomic features of m/z 1778.97, 1866.16, 1934.65, and 2022.46, of which intensities decreased significantly in CRC, were identified as fragments of complement C3f. Therefore, the Fisher‐based model containing five proteomic features was able to effectively differentiate CRC patients from healthy controls and other cancers with a high sensitivity and specificity, and may be CRC‐specific. Serum complement C3f, which was significantly decreased in CRC group, may be relevant to the incidence of CRC. J. Cell. Biochem. 114: 448–455, 2013. © 2012 Wiley Periodicals, Inc.     

Development and evaluation of Leishmania infantum rK26 ELISA for serodiagnosis of visceral leishmaniasis in Iran

The purpose of this study was to prepare recombinant K26 antigen from Leishmania infantum and evaluate its performance by enzyme-linked immunosorbent assay (ELISA) test for serodiagnosis of visceral leishmaniasis (VL) in endemic regions of Iran. The results were compared with those obtained by direct agglutination test (DAT) and whole cell ELISA using crude parasite antigen. Of 93 sera from patients with confirmed VL, 90 sera were positive with rK26 ELISA (sensitivity=96.8%), whereas 85 sera were positive with DAT (sensitivity=91.4%) and 89 sera were positive with whole cell ELISA (sensitivity=95.7%). Of 130 subjects who either had other infectious diseases (n=30) or were healthy (n=100), rK26 ELISA were negative in all cases (specificity=100%), whereas DAT were negative in 116 cases (specificity=89.2%) and whole cell ELISA was negative in 114 cases (specificity=87.7%). The results of this study indicate that the rK26 ELISA is more sensitive and specific than conventional methods and could be used for reliable diagnosis of VL caused by Leishmania infantum.     

Preliminary study on serum levels of mucinous like cancer antigen (MCA) in patients with breast disease: comparison with CEA

MCA (mucinous-like cancer antigen) can be measured in the biological fluids of patients by means of a solid phase enzyme immunoassay. This study describes the results of MCA determination in sera of 230 patients with benign (99) and malignant (131) breast diseases. MCA levels were significantly higher in breast cancer patients than in non cancer patients and in healthy subjects (p less than 0.001). MCA concentrations tended to increase as the stage of the disease advanced. The 95th percentile of MCA value distribution in normal subjects showed a diagnostic sensitivity in breast cancer patients of 16.3% at stage I, 26.2% at stages II-III and 52% at stage IV. In a group of 118 cancer patients, MCA and CEA were tested simultaneously. The diagnostic sensitivity and specificity of MCA and CEA assays was very similar; nevertheless the association of the two tests showed 11 cases with high levels of MCA and low levels of CEA and 9 patients with high levels of CEA and low levels of MCA. Seventy-four out of 118 patients were negative for both markers and in 22 out of 118 patients markers were positive. The new marker MCA appeared to correlate with breast cancer and gave different information complementary to CEA.     

Increase of sensitivity of sputum cytology using high-resolution image cytometry: field study results

Lung cancer remains the leading cause of cancer deaths in the developed world. There is no widely accepted method to screen for this cancer. The most commonly used method remains conventional sputum cytology, but this method is hampered by low sensitivity. We tested the hypothesis that sensitivity of sputum cytology for early lung cancer can be greatly improved by using image analysis of sputum cells, at a modest reduction of specificity.The study was double-blinded and used sputum samples from subjects with well-characterized clinical diagnoses. There were 177 cancers, 98 dysplasias, and 558 normals. The study samples were separated into two independent sets: training set and test set. Sputum samples were collected prospectively from subjects with a high probability of having lung cancer. Seven institutions from five countries participated in the study. All subjects had complete clinical diagnoses which included, as a minimum, negative chest x-rays for all negative cancers, while all cancers had confirmed tissue pathology. Samples were prepared according to the Saccomanno method. For conventional cytology, slides were stained using Papanicolaou stain. For image analysis, slides were stained using a DNA-specific (Feulgen-Thionin) stain. An automated, high-resolution image cytometer was used for measurements.At 90% specificity, sensitivity of 60% can be achieved for adenocarcinoma, compared to only 14% sensitivity of conventional cytology (at 99% specificity). Similarly, 45% sensitivity at 90% specificity can be reached for stages 0 and I lung cancer, compared to only 14% (at 99% specificity) using conventional cytology.Cytometry combined with conventional cytology shows an increase in sensitivity to early-stage cancer and to adenocarcinomas compared to conventional cytology alone. While the results are encouraging, the sensitivity to detect early lung cancer should be further improved to 70-80% at 90-95% specificity before this test can be considered for screening of high-risk individuals for lung cancer. Cytometry (Clin. Cytometry) 50:168-176, 2002.     

Development of an Automated and Sensitive Microfluidic Device for Capturing and Characterizing Circulating Tumor Cells (CTCs) from Clinical Blood Samples

Current analysis of circulating tumor cells (CTCs) is hindered by sub-optimal sensitivity and specificity of devices or assays as well as lack of capability of characterization of CTCs with clinical biomarkers. Here, we validate a novel technology to enrich and characterize CTCs from blood samples of patients with metastatic breast, prostate and colorectal cancers using a microfluidic chip which is processed by using an automated staining and scanning system from sample preparation to image processing. The Celsee system allowed for the detection of CTCs with apparent high sensitivity and specificity (94% sensitivity and 100% specificity). Moreover, the system facilitated rapid capture of CTCs from blood samples and also allowed for downstream characterization of the captured cells by immunohistochemistry, DNA and mRNA fluorescence in-situ hybridization (FISH). In a subset of patients with prostate cancer we compared the technology with a FDA-approved CTC device, CellSearch and found a higher degree of sensitivity with the Celsee instrument. In conclusion, the integrated Celsee system represents a promising CTC technology for enumeration and molecular characterization.     

Data reduction using a discrete wavelet transform in discriminant analysis of very high dimensionality data

We present a method of data reduction using a wavelet transform in discriminant analysis when the number of variables is much greater than the number of observations. The method is illustrated with a prostate cancer study, where the sample size is 248, and the number of variables is 48,538 (generated using the ProteinChip technology). Using a discrete wavelet transform, the 48,538 data points are represented by 1271 wavelet coefficients. Information criteria identified 11 of the 1271 wavelet coefficients with the highest discriminatory power. The linear classifier with the 11 wavelet coefficients detected prostate cancer in a separate test set with a sensitivity of 97% and specificity of 100%.     

Differentiation of serum levels of trace elements in normal and malignant breast patients

The objective of this study was to determine which elements in serum best differentiated breast cancer in a case-control study. Concentrations of 13 elements in serum of 68 breast tumor patients (25 malignant and 43 benign) and 26 healthy controls were measured. Logistic regression with different variable-selection procedures was used to determine a possible configuration of elements. Sensitivity and specificity of the model were calculated to obtain the optimal cutoff point for discriminating malignant breast cancers vs other individuals (including benign breast disease and normal ones). A combination of Cd, Mn, and Fe was found to have a specificity and sensitivity of 100% using forward-type logistic regression, when the cutoff value of the combination score was 52.71. Using stepwise-type logistic regression, a combination of Cr and Mn had a sensitivity of 100% and a specificity of 97.1% when the combination score of 17.4 was chosen as the cutoff. Similar analysis could be implemented to compare the malignant and control groups. Specificity and sensitivity were 100% for Mn (forward and stepwise type) with a cutoff point of 6.40. For the backward regression, specificity was 84.6% and sensitivity was 100% for Zn, with a cutoff point of 869.1. In conclusion, there was a significant difference in concentrations of all 13 elements in serum between breast cancer patients and controls. A combination among Cd, Mn, Fe, Cr, and Zn might be important to determine a differentiating reference for breast cancers if a long-term followed-up study is to be conducted.     

Serum anti-p53 antibodies as a useful marker for prognosis of gastric carcinoma

Mutations in the TP53 gene are the most common genetic alterations in cancer. Accumulation of mutated protein may induce circulating anti-p53 antibodies (anti-p53Ab) in sera of cancer patients. The aim of our work was to evaluate the presence and prognostic value of anti-p53Ab in gastric cancer patients and to investigate whether their presence is related to p53 overexpression in tumor tissue. Anti-p53Ab were analyzed in sera from 111 patients with gastric carcinoma and from 64 healthy donors by ELISA. p53 expression was also quantified by ELISA in biopsies of 54 gastric cancers and 22 healthy gastric mucosas. Significant anti-p53Ab levels were found in 15.3% of patients, whereas none of the 64 donor sera were positive. High levels of p53 expression were detected only in tumor tissue, in 72.2% of cases. A significant correlation was observed between anti-p53Ab and high levels of mutated p53 in tissue (p<0.05). The survival time of serum-positive patients was significantly longer than that of patients with low/negative serum levels, with a survival rate of 41.2% and 14.9%, respectively, over 48 months (p<0.05). Thus, detection of serum anti-p53Ab in gastric cancer patients can be useful to identify a subset of patients with better prognosis.