Аннотация:Lung cancer is the major cause of mortality from cancer in the world, according to various studies. Diagnosis often occurs when the disease is already in an advanced stage. Early diagnosis is limited by the fact that the disease usually occurs asymptomatic, and available screening methods do not meet the requirements for reliable discrimination between patients with lung cancer and without it.
Analysis of exhaled breath condensate (EBC) is a noninvasive method to study the composition of the airway lining fluid and has the potential to evaluate the various respiratory system diseases
The aim of our study was to develop a method for early diagnosis of lung cancer based on exhaled breath condensate analysis by mass spectrometry of high resolution.
2 group of donors were taken for the study: 26 patients with verified lung cancer (21 M, 57 ± 12 years) and 23 healthy nonsmoking donor (19 m, 30 ± 7 years) as a control. Patients were treated at the thoracic department of the Herzen Oncological Institute, Moscow. Most of them were diagnosed with squamous cell carcinoma of various localization, some had adenocarcinoma.
EBC samples were collected via disposable portable condenser RTube® (Respiratory Research, Inc., USA), freeze dried, treated by trypsin and analyzed by nanoflow LC-MS/MS with a 7-Tesla Finnigan LTQ-FT mass spectrometer (ThermoElectron, Germany). By means of Bioworks Browser 3.1SR1(Thermo Electron, Germany) list of direct peptide masses and masses of their fragments was generated, with following identification of proteins in Mascot (MatrixScience version 2.0.04, the UK).
The identified proteins were annotated and analyzed for the following databases: GeneCards, GeneOntology, UniProt, MOPED and BioGPS.
EBC proteome analysis revealed about 300 proteins. Some of them were invariant for both groups of donors. The major EBC proteins were cytoskeletal keratins types I and II, non-keratinic proteins – dermcidin, immunoglobulin alpha, albumin, and others ¬ were also presented.
17 proteins identified exclusively in EBC of lung cancer donors with the initial disease stages were of the greatest interest to us. These proteins can be divided into the following functional groups: regulatory proteins - ATPIF1, DPYSL, PANK2, SHROOM3, SYN1, TBC1D1; cell cycle proteins – BSD, Spindly Protein, DDX20, HSP90A, NUCKS1, SEPT7, SFRS1,3,4,6, WDR13; tumor antigens – Cep290, POTEE. POTEE must be mentioned to be under consideration as a commercial tumor marker, used for target delivery of anticancer drugs.
Thus, we have shown that the proteome EBC analysis may be a promising non-invasive method of early lung cancer diagnosis