Objective: To confirm the role of Tiam1 (T lymphoma invasion and metastasis 1) gene in the proliferation and metastasis of colorectal cancer.
Methods: Proliferative and metastatic abilities of Tiam1 transfectant were investigated by subcutaneous injection of cells and surgical orthotopic transplantation (SOI) in mice.
Results: 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.
Conclusions: 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.