Proteomics-Based Analysis of Clinical Significance of Roundabout Guidance Receptor 4 and Protocadherin 12 in Screening,Diagnosis,and Staging of Colorectal Cancer. (PubMed, Zhongguo Yi Xue Ke Xue Yuan Xue Bao)
Results The target proteins ROBO4 and PCDH12 were screened out through proteomics.Bioinformatics analysis showed that ROBO4 and PCDH12 were highly expressed in CRC patients.Further correlation analysis revealed a positive correlation between ROBO4 and PCDH12 in CRC(R=0.870,P<0.001).The ELISA results of clinical samples showed that compared with the normal group and polyp group,the cancer group presented elevated expression levels of ROBO4 and PCDH12(all P<0.001).There was no statistically significant difference in the expression level of ROBO4 or PCDH12 between the normal group and the polyp group(P=0.586,P=0.550).The ROC curves showed that the diagnostic efficacy of ROBO4,PCDH12,and ROBO4+PCDH12 was 0.787,0.757,and 0.812,respectively,all of which were higher than the diagnostic efficacy of CEA and CA199.Further analysis of serum levels of ROBO4 and PCDH12 with the pathological data of CRC showed that the serum level of ROBO4 was correlated with differentiation degree(P=0.013),pathological stage(P=0.002),lymph node metastasis(P=0.001),and distant metastasis(P=0.026).The serum level of PCDH12 was correlated with differentiation degree(P=0.043),pathological stage(P=0.012),and lymph node metastasis(P=0.001).The ROC curves showed that the diagnostic efficacy of ROBO4,PCDH12,and ROBO4+PCDH12 was 0.637,0.758,and 0.787 for early CRC and 0.872,0.757,and 0.882 for progressive CRC,respectively. Conclusions The serum levels of ROBO4 and PCDH12 demonstrate high diagnostic efficacy for CRC patients and are correlated with the pathological features of CRC.The two proteins are expected to be novel serum biomarkers for the diagnosis and screening of CRC.