RESUMO
Abstract Objective: This study aimed to investigate the effect of Zinc Finger E-box Binding Homeobox 1 (ZEB1) regulation by Micro Ribonucleic acid (miR)-448 on Breast Cancer (BC) cells and their sensitivity to chemotherapy. Methods: miR-448 and ZEB1 mRNA levels in BC and normal tissues were detected by qPCR, and ZEB1 protein was detected by Western Blotting (WB). The correlation between miR-448 and tumor metastasis, clinical staging, and ZEB1 expression was analyzed. MCF-7 cells were transfected or co-transfected with the miR-448 mimic, oe-ZEB1, or their negative controls. Changes in miR-448 and ZEB1 expression were detected by qPCR and WB. Cell proliferation was determined by CCK-8 assays, invasion changes were analyzed by Transwell assays, and apoptosis was detected by flow cytometry. Results: miR-448 expression in BC tissues was lower than that in normal tissues, while ZEB1 expression was increased in the former. ZEB1 expression was lower in BC patients with lymph node metastasis than in those without. In patients with clinical stage I-III BC, miR-448 expression decreased with an increase in tumor stage, which was negatively correlated with ZEB1 expression. Upregulation of miR-448 expression can suppress MCF-7 cell proliferation and invasion and promote apoptosis. Upregulation of ZEB1 expression in cells overexpressing miR-448 can partially reverse the inhibition of BC cell growth induced by miR-448. miR-448 can enhance the sensitivity of cells toward paclitaxel and 5-fluorouracil. Conclusions: miR-448 suppresses cell proliferation and invasion and promotes apoptosis by targeting ZEB1. Moreover, it can increase the sensitivity of cells toward paclitaxel and 5-fluorouracil.
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OBJECTIVE@#To screen the microRNAs (miRNAs) targeting Rictor and investigate their effects in regulating the biological behaviors of colorectal cancer (CRC).@*METHODS@#Human colorectal cancer cell line KM12SM was transfected with the miRNAs targeting Rictor identified by prediction software to test inhibitory effects of these miRNAs on Rictor expression using qRT-PCR and Western blotting. Dual luciferase reporter assay was used to further confirm the binding of these miRNAs to the 3'UTR of Rictor mRNA. Cell survival and colony formation assays were used to investigate the effects of these miRNAs on survival and colony formation in KM12SM cells.@*RESULTS@#miR-152 and miR-448 were identified as the Rictor-targeting miRNAs, which significantly inhibited the expression of Rictor in KM12SM cells ( < 0.05). The two miRNAs were confirmed to bind to the 3'UTR of Rictor mRNA and significantly inhibited luciferase activity in KM12SM cells ( < 0.01, < 0.05); they also showed activities of posttranscriptional modulation of Rictor. Overexpression of miR-152 and miR-448 both significantly inhibited the growth and colony formation of KM12SM cells.@*CONCLUSIONS@#miR-152 and miR-448 can down-regulate the protein expression of Rictor by targeting Rictor mRNA to negatively regulate the growth and colony formation of colorectal cancer cells.
Assuntos
Humanos , Regiões 3' não Traduzidas , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Colorretais , Tratamento Farmacológico , Regulação Neoplásica da Expressão Gênica , MicroRNAs , Farmacologia , Proteína Companheira de mTOR Insensível à RapamicinaRESUMO
MicroRNAs play a crucial role in the progression of spinal cord ischemia/reperfusion injury (SCII). The role of miR-448 and SIRT1 in SCII was investigated in this study, to provide further insights into prevention and improvement of this disorder. In this study, expressions of miR-448 and SIRT1 protein were determined by qRT-PCR and western blot, respectively. Flow cytometry was used to analyze cell apoptosis. The endogenous expression of genes was modulated by recombinant plasmids and cell transfection. Dual-luciferase reporter assay was performed to determine the interaction between miR-448 and SIRT1. The Basso, Beattie, and Bresnahan score was used to measure the hind-limb function of rat. The spinal cord ischemia reperfusion injury model of adult rats was developed by abdominal aorta clamping, and the nerve function evaluation was completed by motor deficit index score. In SCII tissues and cells treated with hypoxia, miR-448 was up-regulated while SIRT1 was down-regulated. Hypoxia treatment reduced the expression of SIRT1 through up-regulating miR-448 in nerve cells. Up-regulation of miR-448 induced by hypoxia promoted apoptosis of nerve cells through down-regulating SIRT1. Down-regulated miR-448 improved neurological function and hind-limb motor function of rats with SCII by up-regulating SIRT1. Down-regulated miR-448 inhibited apoptosis of nerve cells and improved neurological function by up-regulating SIRT1, which contributes to relieving SCII.