TNNT1 facilitates proliferation of breast cancer cells by promoting G1/S phase transition

Aims: Breast cancer is the major diagnosed cancer and the leading reason of cancer related death among women, and the tumor size is one of the risk factors. Therefore, it is significant to reveal the principle of breaking the subtle homeostasis of cell cycle and sustaining chronic proliferation of cancer cells. Main methods: The expression of TNNT1 was examined by qPCR and western blotting. The effect of TNNT1 on cell proliferation was detected by MTT, colony formation and anchorage-independent growth assay. The percent of cells in different cell phase was analyzed by Flow cytometry. The mRNA and protein expression of genes involved in G(1)/S transition was assayed using qPCR and western blotting, respectively. Key findings: The results showed that TNNT1 expression is significantly increased in breast cancer tissues and closely correlated with clinical stage, T and N classification. Further experiments demonstrate that TNNT1 contributes to proliferation of breast cells by promoting G(1)/S transition. Significance: Our results extend the mechanisms of controlling cell cycle and may provide a novel therapeutic target to therapy breast cancer.