RESUMEN
PURPOSE: Breast cancer causes significant mortality in women world over. The lack of efficient and reliable biomarkers and therapeutic targets impedes the treatment of breast cancer. Herein, the role and therapeutic potential of miR-155 was investigated in different breast cancer cell lines Methods: Cell viability was determined by WST-1 and colony formation assays. Transfections were performed by Lipofectamine 2000 reagent. Cell cycle analysis was carried out by flow cytometry and apoptosis was detected by AO (acridine orange)/EB (ethidium bromide) staining. Cell migration and cell invasion were determined by wound healing assay. RNA and protein expressions were determined by qRT-PCR and western blotting, respectively. RESULTS: miR-155 was significantly upregulated in all the breast cancer cells. Suppression of miR-155 in SK-BR-3 cells inhibited the growth and colony formation. The inhibition of SK-BR-3 cell proliferation was found to trigger apoptotic cell death and cell cycle arrest. Induction of apoptosis was also accompanied with enhancement of cytochrome c, Bax caspase 3, 8 and 9and inhibition of Bcl-2. Besides, suppression of miR-155 resulted in the decrease of cell migration and invasion. Bioinformatic analysis revealed MAPK7 to be the potential target of miR-155. The MAPK7 expression was also upregulated in all the breast cancer cells and suppression of miR-155 resulted in its downregulation. CONCLUSION: Taken together, miR-155 may prove essential in the management of breast cancer.
Asunto(s)
Neoplasias de la Mama/enzimología , Neoplasias de la Mama/genética , MicroARNs/metabolismo , Proteína Quinasa 7 Activada por Mitógenos/genética , Proteína Quinasa 7 Activada por Mitógenos/metabolismo , Apoptosis/fisiología , Neoplasias de la Mama/patología , Puntos de Control del Ciclo Celular/fisiología , Línea Celular Tumoral , Proliferación Celular/fisiología , Femenino , Humanos , Células MCF-7 , MicroARNs/antagonistas & inhibidores , MicroARNs/biosíntesis , Metástasis de la Neoplasia , TransfecciónRESUMEN
OBJECTIVE: To investigate the expression of targeting protein for Xenopus kinesin-like protein 2 (TPX2) in breast cancer tissue and to explore its role in proliferation, migration and invasion of breast cancer cells. METHODS: The mRNA and protein expressions of TPX2 in breast cancer tissue and cell lines were assessed by quantitative RT-PCR and Western blot. The effect of TPX2 with RNA interference on proliferation, invasion and migration of breast cancer cells was observed by MTT and Transwell assays. RESULTS: Both mRNA and protein expressions of TPX2 were upregulated in breast cancer tissues compared to tumor-adjacent tissue. TPX2 expression was also upregulated in breast cancer cell lines, and the TPX2 interfered by small interfering RNA could inhibit the proliferation, invasion and migration of breast cancer cells by inhibiting matrix metalloproteinase-2 and matrix metalloproteinase-9. CONCLUSIONS: Significantly upregulated TPX2 expression is observed in breast cancer tissue and cells, and contributes to promote the proliferation, migration and invasion of breast cancer cells.
