Analysis Of Differentially Expressed Proteome In Urinary From Non-small Cell Lung Cancer Patients

Objective: Lung cancer is one of the leading causes of cancer-related death in developed countries, and 80% cases are non-small cell lung cancer(NSCLC). Although continuous improvements of the diagnosis and treatment methods of lung cancer have been achieved, about 60% patients with NSCLC don’t start therapy until they have reached advanced stage. Their five-year survival rates are less than 10%, but for patients with stage Ⅰ NSCLC can up to 70%. Therefore early diagnosis is key to successful treatment of NSCLC. The probability of successful cure could only be increased through optimizing the prescription according to early diagnosis. Hence, it is significant to search for clinical screening methods of early NSCLC. Urine samples are important biomedical materials, which could be used to look for potential disease biomarkers. Proteins in urine are mainly used to reflect renal and urogenital disorders, and most studies are limited to kidney and urinary tract diseases. However, recent studies showed that analyses of urinary proteomics could occur in other non-urogenital diseases and also be used to diagnosis or therapy of these diseases. In addition, studies on urinary proteomics are increasingly valued because of urinary samples are convenient and noninvasive. Considering that analyses for composition and function of proteins in urine would be of great significance to some diseases, especially for the occurring, diagnosis, prevention, and cure of neoplastic disease, so our present study compared urinary proteins among healthy people, patients with lung benign disorders, and patients with NSCLC, in order to find out biomarkers for early screening. At last, aimed to find out a powerful early screening method for patients with NSCLC and increase diagnostic accuracy of early NSCLC.Method: Urinary samples collected from non-neoplastic groups and NSCLC patients were used to extract proteins through ultra high-speed centrifugal precipitation with speed at 200000×g, and grouping was done through 0.9% 1D SDS-PAGE. select targeted stripes to implement digestion and extraction in protein gel. Proteins and peptide mixture after digestion were identified one by one with MS-Thermo-Orbitrap-Velos,and mass spectrometry data were analyzed by HCBI-Human Data with MASCO, to search for differentially expressed proteins, which could be regarded as candidate biomarkers for early screening of NSCLC. Finally, biomarkers related to NSCLC could be determined, also with their pattern for screening and diagnosis.Results: The differences of urinary proteins between non-neoplastic groups and NSCLC patients mainly focused on 90 k Da, 60 k Da and 20 k Da-30 k Da stripes. Abundant gel stripes were cut because of factors caused by protein abundances, and then identification through MS-Thermo-Orbitrap-Velos and analyses through HCBI-Human Data with MASCO were performed. NSCLC group and control group identified1194-2813 and 1313-2740 proteins, and the mean value was2001±363.1 and 1967±505.0, respectively. Four differentially expressed proteins were found in urinary proteins in NSCLC group, including LRG1, CA1(up-regulated proteins) and VPS4 B, YWHAZ(down-regulated proteins). The sensitivity of these four proteins for biomarkers of NSCLC was relatively low when they were used to screen or diagnose independently, while significantly improvement if they were combined.Conclusions: 1. Urinary samples are body fluid with many proteins, peptides and amino acids. Urinary proteins are noninvasive, sensitive and specific and convenient to obtain. Therefore, it is of great value to determine urinary proteins to early diagnosis and evaluation of clinical course and prognosis. 2. Positive correlation is between the expression of LRG1 and CA1 and NSCLC, while negative correlation between VPS4 B and YWHAZ and NSCLC. They could be regarded as biomarkers for early screening, monitoring prognosis and evaluating therapy of NSCLC. 3. The sensitivity of LRG1, CA1, VPS4 B and YWHAZ for biomarkers of NSCLC is relatively low when they are used to screen or diagnose independently, while significantly improvement if they were in combined pattern, which will be of excellent applications to clinical diagnosis and treatment.