Gene

Molecular biology

Biology

Messenger RNA

Cell culture

Cell growth

Cancer research

Biochemistry

Transfection

Reverse transcription polymerase chain reaction

Genetics

Internal medicine

Medicine

Cell

Breast cancer

Cancer

Cancer cell

ObjectiveTo investigate the expression of B cell translocation gene 3 (BTG3) in breast cancer tissues and its effect on proliferation and invasion of breast cancer cells.MethodsThe breast cancer tissue and adjacent cancer tissues from 80 breast cancer patients were selected.The sestern blot and reverse transcription-polymerase chain reaction (RT-PCR) were used to measure the BTG3 protein and mRNA levels in breast cancer tissues and adjacent tissues.The MCF-7 cells were divided into Blank group (no transfection), NC group (transfected with empty vector) and Ex-BTG3 group (transfected with overexpressed BTG3 vector). The cell proliferation was detected by 3- (4, 5-dimethylthiazole-2)-2, 5-diphenyltetrazolium bromide (MTT) assay.The Transwell chamber was used to measure the cell invasiveness ability.The scratch test was used to determine the cell migration ability.The Western blotting and RT-PCR were used to determine the levels of BTG3, transforming growth factor β1 (TGF-β1), human signal transduction molecule 7 (Smad7), E-cadherin, vimentin protein and mRNA. T test and analysis of variance were used.ResultsThe BTG3 protein (0.18±0.06) and mRNA level (0.56±0.07) in breast cancer cells MCF-7 were lower than those in normal breast epithelial cells HBL-100 (0.44±0.09, 1.00±0.04) (t=5.375, 12.203, P<0.05). Compared with the Blank group and the NC group, the optical density value (A) value of MCF-7 cells in the Ex-BTG3 group was decreased (t=4.214, 4.185, 3.941, 3.952, P<0.05), the number of invasive cells was decreased (P<0.05), the scratch area was increased (t=7.426, 7.437, P<0.05), TGF-β1, the level of TGF-β1, Vimentin protein and mRNA were decreased (t=3.012, 3.024, 3.105, 3.108, P<0.05), and the levels of BTG3, Smad7 and E-cadherin protein and mRNA were increased (t=4.516, 4.518, 3.231, 3.118, 3.402, 3.411, P<0.05).ConclusionThe level of BTG3 in breast cancer tissues is decreased, and overexpression of BTG3 can inhibit the proliferation and invasion of breast cancer cells by inhibiting TGF-β1/Smad signaling pathway.Key words: B cell translocation gene 3; Breast cancer; Proliferation; Invasion; Transforming growth factor β1; Human signal transduction molecule 7; Epithelial-mesenchymal transition

Expression of B cell translocation gene 3 in breast cancer tissues and its effect on proliferation and invasion of breast cancer cells