Exploratory study on application of MALDI­TOF­MS to detect serum and urine peptides related to small cell lung carcinoma.

Matrix­assisted laser desorption/ionization time­of­flight mass spectrometry (MALDI­TOF­MS) was employed to analyze differential serum and urine peptides in patients with small cell lung cancer (SCLC) and healthy individuals, and SCLC diagnostic classification models were constructed. Serum and urine samples from 72 patients with SCLC, age­ and gender­matched with 72 healthy individuals, were divided into training and testing sets in a 3:1 ratio. Serum and urine peptides were extracted using copper ion­chelating nanomagnetic beads, and mass spectra were obtained using MALDI­TOF­MS. Peptide spectra for the training set were analyzed, and the classification model was constructed using ClinProTools (CPT). The testing set was used for blinded model validation. For training­set sera, 122 differential peptide signal peaks with a mass of 0.8­10 kDa were observed, and 19 peptides showed significantly different expression [P<0.0005; area under curve (AUC) ≥0.80]. CPT screened 5 peptide peaks (0.8114, 0.83425, 1.86655, 4.11133 and 5.81192 kDa) to construct the classification model. The testing set was used for the blinded validation, which had 95.0% sensitivity and 90.0% specificity. For the training­set urine, 132 differential peptide signal peaks with m/z ratios of 0.8­10 kDa were observed, and 8 peptides had significantly different expression (P<0.0005; AUC ≥0.80). Then, 5 peaks (1.0724, 2.37692, 2.7554, 4.75475 and 4.7949 kDa) were used for classification model construction. The testing set was used for 36 blinded validation, which had 85.0% sensitivity and 80.0% specificity. Among the differential peptides, 3 had the same significant peaks at 2.3764, 0.8778 and 0.8616 kDa, identified as fibrinogen α, glucose­6­phosphate isomerase and cyclin­dependent kinase­1, respectively. The present study highlighted the differences that exist in serum and urine peptides between patients with SCLC and healthy individuals. Serum and urine peptide diagnostic classification models could be constructed using MALDI­TOF­MS, and showed high sensitivity and specificity.

Metal dyshomeostasis based biomarkers of lung cancer using human biofluids.

Lung cancer (LC) is one of the most common causes of cancer-related deaths in the world and it is well known that trace elements play important roles in the carcinogenic process activating and inhibiting enzymatic reactions and metalloproteins, in which they usually participate as cofactors. A cross-sectional study was conducted on 48 lung cancer patients and 39 controls (56 men and 31 women), aged 44-76 years between March 2011 and June 2012. Eleven elements have been included in the study: V, Cr, Mn, Fe, Co, Cu, Zn, Se, Mo, Cd, and Pb, some of them considered toxic (V, Cd, Cr and Pb), while others are essential (Co, Mo, Se, Fe and Zn), and they have been analyzed by ICP-QQQ-MS in serum, urine and for the first time in bronchoalveolar lavage fluid (BALF). In order to understand the involvement of metals in this process, an analytical metallomic approach based on non-denaturing precipitation of proteins (NDPP) has been optimized for the fractionation of high molecular mass (HMM) and low molecular mass (LMM) metal species, in order to distinguish between metal species that affect the biological activity and toxicological potential of the elements. In this work, the NDPP followed by the analysis of metals by ICP-QQQ-MS has been applied for the first time to serum, urine and BALF samples from lung cancer patients and controls in order to get metal-size molecule profiles (MSMP), which can be used as metal-based biomarkers of altered metabolic processes such as oxidative stress and homeostasis. In this sense, we have demonstrated that several metals are good biomarkers when they are related to labile complexes, complexed with low molecular mass ligands, or in the form of metalloproteins (i.e. V and Cr in HMM and Cu in LMM), which has been described for the first time. On the other hand, metal dyshomeostasis biomarkers are proposed using metal ratios and correlations. Finally, the ratios between elements were shown to be important biomarkers for lung cancer in serum (V/Mn, V/Pb, V/Zn, Cr/Pb), urine (Cr/Cd, Mn/Cd, V/Cd, Co/Cd, Cd/Pb) and BALF (V/Cu), which reflects the dyshomeostasis of metals in lung cancer. In this sense, several metals are correlated to others suggesting also the existence of an interconnected homeostasis in lung cancer.

Development and validation of a liquid chromatography-tandem mass spectrometry assay for the quantification of lurbinectedin in human plasma and urine.

Lurbinectedin is a novel highly selective inhibitor of RNA polymerase II triggering caspase-dependent apoptosis of cancerous cells. This article describes the development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay to quantify lurbinectedin in human plasma and urine. Plasma samples were pre-treated with 1 M aqueous ammonia after which they were brought onto supported liquid extraction (SLE) columns. Lurbinectedin was eluted from the columns using tert-butyl methyl ether (TBME). Urine was first diluted in plasma and lurbinectedin was extracted from this matrix by liquid-liquid extraction using TBME. Samples were measured by LC-MS/MS in the positive electron ion spray mode. The method was linear over 0.1-100 ng/mL and 1-1000 ng/mL in plasma and urine, respectively, with accuracies and precisions within ±15% (20% for LLOQ) and below 15% (20% for LLOQ), respectively. The method was developed to support a mass balance study in which patients received a dose of 5 mg lurbinectedin.

Urinary metabolomic study of non-small cell lung carcinoma based on ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

Metabolic profiles from human urine reveal the significant difference of carnitine and acylcarnitines levels between non-small cell lung carcinoma patients and healthy controls. Urine samples from cancer patients and healthy individuals were assayed in this metabolomic study using ultra high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. The data were normalized by the sum of all intensities and creatinine calibration, respectively, before orthogonal partial least squares discriminant analysis. Twenty differential metabolites were identified based on standard compounds or tandem mass spectrometry fragments. Among them, some medium-/long-chain acylcarnitines, for example, cis-3,4-methylene heptanoylcarnitine, were found to be downregulated while carnitine was upregulated in urine samples from the cancer group compared to the control group. Receiver operating characteristic analysis of the two groups showed that the area under curve for the combination of carnitine and 11 selected acylcarnitines was 0.958. This study suggests that the developed carnitine and acylcarnitines profiling method has the potential to be used for screening non-small cell lung carcinoma.

Prospective study of urinary and serum cross-linked N-telopeptide of type I collagen (NTx) for diagnosis of bone metastasis in patients with lung cancer.

BACKGROUND: Many cancers metastasize to bone, which may cause an increase in bone resorption because of the direct effects of the tumor itself or osteoclastic activation. PATIENTS AND METHODS: Levels of urinary cross-linked N-telopeptide of type I collagen (uNTx) and serum cross-linked N-telopeptide of type I collagen (sNTx) were measured in 100 patients with lung cancer and 50 patients with benign respiratory disease using the Osteomark NTx urine and serum assays (Osteomark, Princeton, NJ). Bone metastasis was diagnosed by bone scintigraphy. Receiver operating characteristic (ROC) analysis was used to evaluate the detection of bone metastasis. Sensitivity and specificity to detect bone metastasis were calculated when cutoff points were set to 64 nmol bone collagen equivalents (BCE)/mmol Cr for uNTx and 22 nmol BCE/L for sNTx. RESULTS: Patients with lung cancer and bone metastasis had significantly higher levels of both uNTx and sNTx (uNTx median [range], 61.3 [22.7-593.1] nmol BCE/mmol creatinine [Cr]; sNTx median [range], 19.7 [10.7-97.1] nmol BCE/L) than did patients with lung cancer without bone metastasis (uNTx median [range], 45.2 [19.8-153.0] nmol BCE/mmol Cr; sNTx median [range], 16.7 [11.0-28.4] nmol BCE/L), or patients with benign respiratory diseases (uNTx median [range], 40.6 [15.2-155.9] nmol BCE/mmol Cr; sNTx median [range], 14.8 [9.5-55.5] nmol BCE/L.). There was good correlation between uNTx and sNTx (R = 0.807). Area under the curve (AUC) for ROC was 0.743 for uNTx and 0.712 for sNTx. The sensitivity and specificity for the diagnosis of bone metastasis were 48.0% and 86.0%, respectively, using uNTx, and 40.0% and 87.0%, respectively, using sNTx. CONCLUSION: This prospective study indicates equivalency between sNTx and uNTx in sensitivity and specificity to detect bone metastasis, and both uNTx and sNTx may have value as aids in the diagnosis of bone metastasis in patients with lung cancer.

Positive urinary cytology in patients with lung cancer in the absence of obvious urine tract metastases.

PURPOSE: To study the phenomenon of positive urine cytology in patients with lung cancer in the absence of obvious urothelial metastases. PATIENTS AND METHODS: 150 patients with small (SCLC) and non-small cell lung cancer (NSCLC) of all stages and 3 control groups were prospectively studied. Immunocytochemical study (cytokeratins 7-20, TTF1) in all positive urine specimens and chemokine profile (CXCR4, CCL21) study of the primary tumor in selected positive patients was performed. In experimental study, C57Bl/6 BALB/C mice injected with LLC lung and 4T1 mammary cancer cells were used for the detection of positive urine cytology. RESULTS: 11% of patients with NSCLC, 7% of patients with SCLC and none of the control group had positive urine cytology. In NSCLC, metastatic disease and high tumor burden positively correlated (p=0.01 and 0.03 respectively) with the phenomenon. In SCLC, correlation with extensive disease and multiple metastatic sites (p=0.02 and 0.04 respectively) was found. No correlation was found in either group with: age, gender, histology, performance status, line of chemotherapy, previous platinum-based chemotherapy, adrenal metastases, renal function, abnormal urinary sediment, response to chemotherapy and overall survival (p=0.9). Distinctive chemokine expression was identified in positive patients studied and was not observed in negative patients (×2 p=0.008). In the experimental study, only the LLC lung cancer cells were detected in the urine cytology of mice. CONCLUSION: This phenomenon, carrying undefined pathophysiological mechanisms, seems to characterize only patients with metastatic/extensive disease and high tumor burden. Further studies are needed to validate our preliminary chemokine expression results.