| Colorectal cancer (CRC) is ranked the fifth in cancer-related deaths in China and third in frequency in men and second in women. The high mortality rate caused by this disease is to a significant extent associated with the poor diagnosis at its presymptomic stages. When CRC is detected early, more than 90% of persons with the disease live at least 5 years beyond diagnosis. Unfortunately, only 37% of colorectal cancers are diagnosed before they have spread. Furthermore, it's important to identify those prognostic factors, which is a primary basis for therapeutic protocol selection and accurate prognosis of patients with colorectal cancer.Currently, there are some difficulty in early diagnosis, accurate prognosis estimate and early recurrence or/and metastasis detection. All the non-invasive detection techniques, which were used for clinical and screening, lack adequate sensitivity and specificity. The most reliable prognostic factor identified to date in colorectal cancer is the staging of disease at the time that treatment is initiated. Although the modified Dukes staging is commonly used worldwide, the number of applied variations makes correlation of different studies less than ideal. On the other hand, follow-up is carried out to find potentially curable recurrences. Detection of these recurrences can be worthwhile in terms of survival. Therefore, it is essential that more accurate and sophisticated methods be developed for this purpose.Because of the multifactorial nature of the colorectal cancer, it is very likely that a combination of several markers will be necessary to effectively detect and predict prognosis of the colorectal cancer. Proteomic methods detect the functioning units of expressed genes, through biochemical analysis of cellular proteins, to provide a protein fingerprint. The proteomic reflects both the intrinsic genetic programme of the cell and the impact of its immediate environment and is therefore valuable in biomarkerdiscovery. Distinct changes that occur at the protein level during the transformation of a normal cell into a neoplastic cell include altered expression, differential protein modification, changes in specific activity, and inappropriate localization, all of which may affect cellular function. SELDI-TOF (surface-enhanced laser desorption/ionization time of flight) mass spectrometry is one of the recently developed sophisticated technologies, which, based on capturing proteins/peptides by chemically modified surface, is specifically powerful for analyzing the complex biological samples. This technology, combined with bioinformatics, has been successfully used to analyze the complex serum proteins to explore the cancer-specific 'fingerprints' or 'patterns'.Methods:182 serum samples including 55 colorectal cancer (CRC) patients, 35 colorectal adenoma (CRA) patients and 92 healthy people were detected by SELDI-TOF-MS. The data of spectra were analysed by the bioinformatics tools like artificial neural network (ANN) and support vector machine (SVM). The median follow-up time of the patients of Dukes'A, B, C was 20 months (12-24months). Using SELDI-TOF-MS, we expect to find some undocumented prognostic factors and create an individual risk assessment model for predicting the prognosis of the patients with colorectal cancer. We also used SELDI-TOF-MS to detect the serum of post-operation patients at intervals of 3 months, 6 months and 12 months to investigate the dynamic change of the serum protein fingerprint.Results:1. Phosphate buffer containing 0.5% CHAPS (pH 7.4) was added to serumsample and Cibacron Blue 3GA (Sigma) was added into the mixtures to delete serum albumin. The modified protocol of serum protein profiling was stable and repeatable, and applicable to other malignant tumor. Hydrophobic surface arrays (H4 chips) used for serumbiomarker discovery of the colorectal cancer have the advantage over other chips.2. Through noise filtration conducted by Ciphergen ProteinChip Software 3.1, there were 61 peaks detected for discriminate CRC from H...
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