RESUMO
Objective: To investigate the inhibitory effect of capsaicin on the growth of breast cancer MDA-MB-231 cells transplanted tumour in nude mice and its possible molecular mechanism. Method: Transplanted tumor model of breast cancer MDA-MB-231 cells in nude mice were established. Then the tumor-bearing mice were randomly divided into 4 groups:model group, and low, medium and high-dose capsaicin groups (5, 10, 20 mg·kg-1). Mice of low, medium and high-dose capsaicin groups (5, 10, 20 mg·kg-1) were intraperitoneally injected with the corresponding dose of capsaicin, and the model group was injected with the same volume of phosphate buffer saline (PBS), once every 3 days, for a total of 8 times in succession. Body weight of mice and transplantation tumor volume were measured before each injection of capsaicin. Mice of each group were put to death 24 h after the last administration, and then the tumor volume, mass and the tumor inhibitory rate were calculated. The protein expression levels of high mobility group box 1 (HMGB1) and Toll-like receptors 4(TLR4) were measured by immunohistochemistry and Western blot. Result: No significant difference was observed between each group in body weight. However, compared with the model group, capsaicin (5, 10, 20 mg·kg-1) remarkably inhibited the tumor volume and mass (PPP-1) also markedly inhibited the protein expression levels of HMGB1 and TLR4 (PConclusion: Capsaicin remarkably inhibits the growth of breast cancer MDA-MB-231 cells transplanted tumour in nude mice, and the possible mechanism may be related to the down-regulation of HMGB1 and TLR4 at the protein level.
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Objective: To investigate the effect of capsaicin on the migration and invasion of human breast cancer MCF-7 cells and the underlying molecular mechanism. Method: Three capsaicin intervention groups of different concentrations (25, 50, 75 μmol·L-1) and a blank group were set up. After MCF-7 cells were treated with different concentrations of capsaicin (25, 50, 75 μmol·L-1) for 24 h, the cell migration and invasion abilities were assessed by Transwell migration and invasion assay, respectively. Meanwhile, the mRNA level of silent information regulator 2 homolog 1 (SIRT1) and DNA polymerase δ catalytic subunit p125 encoding gene POLD1 (POLD1) were detected by Real-time polymerase chain reaction (Real-time PCR). The protein levels of SIRT1 and DNA polymerase δ catalytic subunit p125 (p125) were detected by Western blot. Result: Compared with the blank group, the number of transmembrane cells was significantly reduced, and the mobility was significantly decreased (P-1) in MCF-7 cells for 24 h. Capsaicin (25, 50, 75 μmol·L-1) significantly down-regulated the mRNA and protein expressions of SIRT1 (P-1) in MCF-7 cells for 24 h. Furthermore, capsaicin (25, 50, 75 μmol·L-1) also significantly down-regulated the mRNA expression of POLD1 and the protein expression of p125 (P-1) in MCF-7 cells for 24 h. Conclusion: Capsaicin remarkably inhibits the cell migration and invasion of breast cancer MCF-7 cells, and the possible mechanism may be related to the down-regulation of SIRT1 and POLD1 mRNA expression levels and SIRT1 and p125 protein expression levels.
RESUMO
This work aimed to observe the effects of short hairpin RNA (shRNA)-silenced FBI-1 (factor that binds to the inducer of short transcripts of human immunodeficiency virus-1) on proliferation and apoptosis of triple-negative breast cancer cell line MDA-MB-231. qRT-PCR and Western blot analysis were applied to detect the mRNA and/or protein expression of FBI-1, Bcl-2, Bax, cleaved-Caspase 3 and Survivin. RNA interference method was used to silence FBI-1 expression in MDA-MB-231 cells. CCK-8 and colony formation assay were employed to detect the cell proliferation. Flow cytometry was employed for examining cell apoptosis. In vivo tumorigenicity of MDA-MB-231 cells was detected by tumor transplantation in nude mice. The results showed that the mRNA and protein expressions of FBI-1 were higher in MDA-MB-231 cells compared with those in normal human mammary epithelial cells MCF-10A. FBI-1 gene silencing inhibited proliferation and induced apoptosis of MDA-MB-231 cells in vitro, together with decreased Bcl-2 and Survivin protein expression, increased Bax protein expression and activated Caspase 3. Moreover, FBI-1 gene silencing inhibited the tumorigenesis of MDA-MB-231 cells in vivo. These results suggest that silencing of FBI-1 gene inhibits proliferation, induces apoptosis and suppresses the tumorigenesis of MDA-MB-231 cells.