Identification of novel diagnostic biomarkers in stages I-IV colorectal cancer

Abstract Background Additional new biomarkers that aid in detecting colorectal adenocarcinoma early are definitely needed. Here, we report that tumor-specific CDX2, CD74, HER2, CD104, and CD26 genes are differentially expressed in the tumor microenvironment (stages I-IV) in patients with colorectal cancer. Material and methods Tumor CDX2, CD74, HER2, CD26 , and CD104 expression levels were studied by immunohistochemistry and RT-qPCR. Tissues from 210 patients with CRC (stages I–IV) were used. Additionally, gene expression ( CDX2, CD74, HER2, CD26, and CD104 ) of CRC patients, CRC with metastasis, and normal tissues were identified using 4 GEO datasets. Results At the mRNA and protein levels, CDX2 was more highly expressed in tumor tissue (I–IV) than in surrounding normal tissue ( P < 0.0001). Furthermore, the ROC curve analysis demonstrated that CDX2 can be a suitable biomarker at all stages. CD74 and CD104 showed a significant increase in expression. However, CD26 did not show any significant increase in mRNA and protein expression. The results of the GEOR2 analyses also confirmed the present results. Conclusions This proof-of-principle study demonstrated that CDX2 is a biomarker for diagnosis and prognosis strategies for CRC. On the other hand, CD74 and CD104 are recommended for diagnosis in stages I and II. The results justify prospective validation to clarify the clinical impact of these biomarkers in cancer diagnosis.