Effect of Tiam1 overexpression on proliferation and metastatic potential of human colorectal cancer

Abstract

To confirm the role of Tiam1 (T lymphoma invasion and metastasis 1) gene in the proliferation and metastasis of colorectal cancer. Proliferative and metastatic abilities of Tiam1 transfectant were investigated by subcutaneous injection of cells and surgical orthotopic transplantation (SOI) in mice. The expression of Tiam1 led to a pronounced increase in HT29/Tiam1 cell growth starting from day 7, up to 2.5 fold increase of tumor volume at day 20 post injection. Tumors in the HT29/Tiam1 group receiving surgical orthotopic implantation were significantly heavier than those in HT29/mock group (t = -14.916, P < 0.01). In vivo metastasis assay by SOI showed that in HT29/Tiam1 group, 7/7 of mice developed peritoneal metastases and 4/7 had hepatic lesions. In addition, one of the seven HT29/Tiam1 group mice had tumors in lung, spleen and lymph nodes. In the HT29/mock group, only 2/7 of animals had peritoneal metastases and none produced detectable tumor in the liver. Tiam1 gene plays an important role in the proliferation, invasion and metastasis of colorectal cancer. It may serve as a useful clinical marker for tumor progression and metastasis of colorectal cancer.