Transforming growth factor-β1 in invasion and metastasis in colorectal cancer

Abstract

Aim: To investigate the role of TGF β1 in invasion and metastasis in colorectal cancer by analysing TGFβ1 correlated with depth of tumor invasion, stage and metastasis. Methods: Serum TGFβ1 levels were determined in 50 patients with colorectal cancer and 30 healthy volunteers using a TGFβ1 enzyme-linked immunosorbent assay. TGFβ1 expression in primary and lymph node metastatic lesions were detected in 98 cases of colorectal cancer by immunohistochemical staining and in situ hybridization. Results: Serum levels of TGFβ1 in patients with colorectal cancer (40±18 μg.L-1) were significantly higher than those in the healthy control group (19±8 μg.L-1), P<0.05. Elevated levels of serum TGFβ1 were found in 60 % of patients with colorectal cancer when the mean +2 s was used as the upper limit of the normal range (35.1 μg.L-1). Increases in serum TGFβ1 levels were significantly associated with Dukei's stage (P<0.05), but there was no significant difference between Dukei's stage B patients and Dukei's stage C patients. In the cytoplasm of cancer cells, TGFβ1 was immunostained in 37.8 % (37/98) of colorectal cancer, and this expression was confirmed by in situ hybridization. Among 35 cases of colorectal cancer with lymph node metastatic lesions, TGFβ1 positive staining was found in 18 (51.4 %) cases of primary tumor, and 25 (71.4 %) cases with lymph node metastatic lesions, respectively. Of 17 cases with no staining in the primary lesion, 7 (41.2%) cases showed TGFβ1 staining in the metastatic lesion. Serum TGFβ1 levels and TGFβ1 expression in colorectal cancer tissues were correlated significantly with depth of tumor invasion, stage and metastasis. Patients in stage C-D, T3-T4 and with metastasis had significantly higher TGFβ1 levels than patients in stage A-B, T1-T2 and without metastasis (P<0.05). Conclusion: These results suggest that transforming growth factor-β1 is closely related to the invasion and metastasis of colorectal cancer. It increased the invasive and metastatic potential of tumor by altering a tumor microenvironment. TGFβ1 may be used as a possible biomarker.