| Cervical cancer(CC) is one of the most common cancers in women, of which the incidence was only second to breast cancer. Patients with advanced stage disease have a 5-year survival rate between 9% and 64% and patients with stage IB or IIA disease have an overall 5-year survival rate of between 66% and 95%, so early diagnosis of CC can significantly increase the survival rate of patients. Traditional methods of diagnosis of cervical cancer, such as cell method, observation method, and colposcopy, have shortcomings such as poor sensitivity and poor specificity. So it is urgent to find a new diagnostic method that can accurately early detection of cervical cancer. Using tumor markers for early diagnosis of cancer is a new kind of diagnostic method developing in recent years, and some tumor markers have already been applied in clinical.Urine, dialysis fluid by kidney, holding advantages of non-invasive, simple and convenient sampling, is the ideal screening marker of specimens. This study analysis the urine proteins from normal people and patients with cervical cancer to screen differential proteins and aim to look for early diagnosis tumor markers associated with cervical cancer.We gathered 43 patients with cervical cancer and 47 cases of healthy women urine samples, including 13 cases of urine samples from cervical cancer patients and 7 cases of urine samples from healthy women as the experimental group; 30 cases of urine samples from cervical cancer patients and 40 cases of urine samples from healthy women as a validation set. All urine samples were performed to ultracentrifugation method to precipitate urine proteins, and then, the proteins were reduction by Dithiothreitol(DTT). After that, the oteins were added wash buffer and ultracentrifugation for second time. At last, we got the final protein pellet. Urine proteins precipitated by ultracentrifugation are characterized by 1D SDS-Page after quantified. The proteins were digested in gel by trypsin, and then, the peptides were extracted from the gel by acetonitrile, which were identified by mass spectrum(MS). When the protein unique to cervical cancer patients and healthy women applied to GO analysis, we known in which biological process the protein participate. For the proteins belonged to both, we screened different expression proteins by statistical method, which the proteins were analysis by cluster and GO method. After all the bioinformatics analysis, we expected to find some potential diagnostic value cancer markers from urine.In experimental set, we identified 4135 proteins(FDR<0.01) in CC patient's urine(CC_urine), from which 2158 proteins contain more than two unique peptides and 4347 proteins(FDR<0.01) in healthy women's urine(HW_urine), from which 2689 proteins contain more than two unique peptides. The GO analysis result showed that the proteins unique to cervical cancer patients were significantly enriched in immune system process, and the proteins unique to healthy women biological adhesion. From the common proteins, we found 84 up-regulated proteins and 82 down-regulated proteins by statistical method. After analysis by cluster, we found that only the up-regulated proteins could be divided into patients group and healthy group and the GO analysis result showed that the up-regulated proteins were enriched in immune system process too. Eventually, we found three proteins, of which S100A7 and CEACAM8 were unique to CC; DPP4 belonged to both groups. In the validation set, the sensitivity of S100A7 and CEACAM8 were 73% and 87%, of which the specificity 93% and 88% by double blind test. The ROC analysis of DPP4 showed the sensitivity and specificity were 67% and 76%, respectively. Based this study, we can envision that the urine proteome of cervical cancer was different from urine proteome of healthy women. S100A7 and CEACAM8 were potential biomarkers for cervical cancer. |
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