Activin A as a novel biomarker for colorectal adenocarcinoma in humans.

ABSTRACT

OBJECTIVE: Early diagnostics of colorectal cancer is complicated by the lack of reliable serum biomarkers. This study aimed to investigate if the serum level of activin A can be used for diagnostics of this disease. PATIENTS AND METHODS: In this study we measured the level of activin A in patients with colorectal adenocarcinoma, benign colorectal polyps, as well as in healthy subjects. RESULTS: We found that the level of activin A was significantly higher in patients with colorectal adenocarcinoma, as compared to patients with polyps and healthy controls. Furthermore, activin A levels correlated well with the stage of colorectal cancer. The level of activin A was substantially reduced in post-operative patients. Immunohistochemical staining demonstrated that high levels of activin A were present in the adenocarcinoma tissue samples but not in the non-cancerous samples. RT-PCR further confirmed that mRNA of ßA subunit of activin A is significantly over-expressed in the majority of cancerous samples. Western blotting results further demonstrated the elevated level of activin A in cancer samples. CONCLUSIONS: Taken together, the findings suggest that colorectal adenocarcinomas directly secret activin A into the blood stream. Measuring the serum level of activin A might be used as a reliable diagnostic and screening tool in clinical practice.