To screen differentially expressed proteins in serum of patients with renal clear cell carcinoma (RCC) before and after operation by protein chip technique and to explore its clinical significance.

From October 2015 to October 2016, 89 patients with renal clear cell carcinoma (RCC) who underwent urological surgery in the First Affiliated Hospital of Xinjiang Medical University were selected as the RCC group, and 100 healthy volunteers and non-RCC patients were selected as the control group. The RCC group was followed up for 1 year after operation. Serum differential proteins were detected by surface enhanced laser time of flight mass spectrometry (SELDI-TOF-MS) and CM10 weak cation exchange protein chip. Linear Support Vector Machine (SVM) method was used to establish a protein fingerprint diagnosis model, leaving a cross validation model to identify the effect. The serum differential proteins were analyzed by ZUCI-PDAS protein mass spectrometry data analysis system.

The protein of mass-charge ratio (M/Z) 2745 was differentially expressed between RCC group and control group, and corresponding protein is Histatin-3, its expression level was lower in RCC group than that in control group before operation (P<0.05). The preoperative expression level of renal cell carcinoma group was lower than that of the follow-up group 1 month, 3 months, 6 months and 12 months after operation (P<0.05). The expression level at 3, 6, 12 months after operation was significantly higher than that at 1 month after operation (P<0.05); There was no significant difference between 6 months, 12 months after operation and 3 months after operation (P>0.05). According to the different expression levels of Histone-3 in the two groups, ROC curve analysis showed that the area under the curve(AUC) was 0.804, sensitivity was 86.7%, specificity was 66.7%. A certain boundary of protein expression intensity was used as a marker, the sensitivity of predicting renal clear cell carcinoma was 86.3%(76/89), and the specificity was 88%(88/100).

The expression of Histone-3 in renal cell carcinoma was different from that in healthy people, and the expression level of Histone-3 increased after operation, suggesting that Histone-3 is correlated with renal cell carcinoma and may become a new molecular marker of renal clear cell carcinoma.